JP2012160867A - Illumination apparatus and image reading apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination apparatus having a simple structure and manufactured inexpensively, which is capable of irradiating a read surface with linear light of a light quantity adapted to the characteristics of a reading optical system.SOLUTION: The illumination apparatus which scatters and reflects light from a light source and irradiates the read surface with linear light is provided with: a light guide which comprises a light scattering surface scattering the light from the light source in a line direction along the read surface and a light emitting surface emitting the light from the light scattering surface, toward the read surface; and the light source disposed at one end face of the light guide. The light source is disposed on one end face of the light guide with a predetermined interval therebetween. A reflector is adhered on the other end face of the light guide with an adhesive material of high light transmissivity therebetween.

Description

  The present invention relates to a light source unit in an image reading apparatus such as a scanner device, a copying machine, or a facsimile, and relates to an improvement in a light source mechanism that irradiates light on a reading surface.

  In general, a light source unit in an image reading apparatus such as a scanner device or a copying machine irradiates light from a light source to a reading platen as disclosed in, for example, Patent Document 1 and collects reflected light by a photoelectric conversion sensor. It is widely known as a device for photoelectric conversion.

  As this light source unit, a light source lamp is disposed on a scanning carriage that moves along a platen as disclosed in Patent Document 2, and reflected light of light emitted from the light source lamp is converted into a photoelectric conversion sensor by a condenser lens. An image is formed. The photoelectric conversion sensor is composed of a line sensor, and the image on the platen is read in line order while moving the scanning carriage in the sub-scanning direction.

  In the image reading apparatus having such a configuration, the light source unit is required to emit uniform light in the main scanning direction (line sensor arrangement direction). For this reason, conventionally, a rod-like light emitter such as a fluorescent lamp (cold cathode tube) or an LED array is used as a light source lamp, or a rod light source that diffuses a point light source along a reading line and emits it from a predetermined angle is used. .

  For example, Patent Literature 3 proposes an illuminating device in which a light scattering surface of a light guide is provided with a surface with a minute angle and a convex surface, and the illuminance is uniform in the longitudinal direction of the light guide. An illumination device is known in which light incident from a light source is incident on a surface at a minute angle, and a portion of the reflected light beam is incident on a convex surface, reflected, and emitted to an irradiated surface. At this time, the other end surface of the light guide (the surface facing the light incident surface from the light source) is subjected to aluminum vapor deposition, metallic luster paint application, light diffuse reflection paint application, or the like.

Further, in Patent Document 4, a rod-shaped light guide body in which a surface facing a light incident surface from a light source is mirror finished is low comforted. According to the present invention, the incident light is retroreflected toward the light source, and is uniformly scattered in the longitudinal direction by the light scattering pattern provided on the bottom surface of the light guide, etc., so that the illuminance of the emitted light is made uniform. be able to.

JP 2007-074019 A JP 2005-234297 A Japanese Patent Laid-Open No. 2001-5122 JP 2006-85975 A

  As described above, a light source unit structure in which a light guide is provided along a reading line and light is introduced from a light emitting body such as an LED when the image reading surface is irradiated with uniform linear light is disclosed in the above patent. It is known from documents 3, 4 and the like. In this case, conventionally, light is incident on the light guide from at least one light emitter from the end face of the light guide, or light is incident on the light guide from a plurality of light emitters having different wavelengths.

  The light guide is configured to irradiate a uniform amount of light as a linear light beam along the reading line of the reading surface, and the reflected light from the reading surface is imaged on the line sensor by the condenser lens. Yes. The condenser lens is composed of one or a plurality of lens units (convex lens configuration). As described above, it is known that light emitted from a light emitter is incident from the end face of the light guide and is reflected in the light guide to cause unevenness in the emitted light.

In order to solve such a problem, conventionally, the other end surface of the light guide is mirror-finished as described in Patent Documents 3 and 4 so that the amount of light emitted from the light guide to the reading surface is uniform. The amount of light emitted from the light guide is made uniform by performing aluminum vapor deposition, applying a metallic luster paint, or applying a light scattering reflective paint.

However, when the other end face is directly vapor deposited, it is necessary to attach the other end face of the light guide parallel to the vapor deposition face in the pot of the vapor deposition apparatus. There is a problem in that light leaks from the location and the amount of reflected light tends to fluctuate. Also, when mirror finishing, it is necessary to attach the other end of the light guide parallel to the finished surface, and the installation error immediately leads to specular spots and loss of flatness, and the reflectivity is low. There is a problem that it tends to fluctuate. Furthermore, in the case of coating processing, it is also necessary to mount the other end face of the light guide parallel to the coating processing, and the mounting error immediately leads to the occurrence of specular spots and loss of flatness, and the reflectance is low. There are fluctuating problems. As a result, an appropriate light quantity characteristic cannot be obtained. Furthermore, there is a problem of productivity because processing accuracy is involved.

Further, it is known from the characteristics of the condenser lens that the light passing through the lens unit attenuates the amount of light passing through the periphery of the lens relative to the amount of light passing through the center of the lens. Therefore, the amount of light emitted from the light guide needs to be high at both ends of the reading line and low at the center.

  This is generally known as the cosine fourth law (the illuminance after incidence is proportional to the cosine fourth power when the incident angle incident on the lens is θ). For this reason, even if the linear light that irradiates the reading surface is evenly configured in the main scanning direction, the amount of light that is photoelectrically converted by the line sensor is the sensor output value for light that has passed through the center of the lens and light that has passed through its periphery. It will be different. At this time, the output value of the sensor is high at the center of the lens and low at the periphery.

  In view of this, the present inventor configures a light source for introducing light into the end face of the light guide body by a plurality of chip-shaped light emitters, regulates the distance between the light guide body and the light source, and efficiently guides light from the light source. By providing a reflector to be incident on the light body, further providing an inclined surface on the other end surface of the light guide, and providing a reflector on the inclined surface, the light amount of the linear light is increased at both ends and the central portion is reduced, It came to the idea that it is possible to make the light intensity other than both ends uniform.

In addition, a reflector cut out in accordance with the outer shape of the other end surface as a reflecting surface is pasted with a double-sided tape, and it is only necessary to manage the reflecting sheet of the reflecting plate to be punched. Even if a little skill is required to stick, the work is easy and excellent workability, and the amount of reflected light and the fluctuation of reflectance due to light leakage are suppressed compared to the conventional method, and the result is appropriate. It is possible to provide an illumination device that can obtain light quantity characteristics.

The present invention provides a light source unit that can emit light with a light amount suitable for the characteristics of a reading optical system when irradiating a reading surface with linear light, has a simple structure, and can be manufactured at low cost. That is the issue.
It is another object of the present invention to provide a light source unit that is free from unevenness of light when light is introduced from a plurality of light emitters into a light guide that generates linear light, and at the same time is suitable for light amount characteristics.

  In order to achieve the above object, the present invention is an illuminating device that scatters and reflects light from a light source to irradiate a reading surface with linear light, and scatters light from the light source in a line direction along the reading surface. A light guide having a light scattering surface and a light emitting surface that emits light from the light scattering surface toward the reading surface; and a light source disposed on one end surface of the light guide. Is disposed at one end face of the light guide member at a predetermined interval, and a reflector is attached to the other end face of the light guide member through an adhesive material having high light transmittance.

Further, in the present invention, the pressure-sensitive adhesive material is made of a sheet-like material having a light transmittance of 90% or more, and the reflection plate has a sheet base material having a reflection surface on the front and back sides of the pressure-sensitive adhesive material. It comprised so that it might consist of a sheet | seat material which piled up the peeling sheet provided with the peeling surface on the side.

Furthermore, the present invention is configured such that the other end surface of the light guide body forms an inclined surface, and the reflector is attached to the inclined surface.

In addition, the light guide has a light emission surface formed by a circumferential surface, the reflection surface is formed at a position separated by a predetermined distance outside the circumferential region, and the light source includes one light emitter, the circumferential surface It arrange | positioned between the center of the circle | round | yen which forms a surface, and a circumferential surface.

Further, the configuration will be described in detail. In the light guide, the light emitting surface is formed by a circumferential surface, the reflecting surface is formed at a position separated by a predetermined distance outside the circumferential region, and the light source includes a first light source, And the second light emitter. The first light emitter is disposed between the center of the circle forming the circumferential surface and the circumferential surface of the first light emitter. Are arranged in the circumferential region according to the separation distance of the light scattering surface.

Further, a reflector is provided between the light guide and the light source to form a reflecting surface that regulates a light irradiation angle of the light source to the end surface of the light guide, and the light guide and the light source are interposed via the reflector. Are held by the holding member.

The present invention further includes a substrate on which the light source is mounted, and a heat radiating member that receives and radiates heat generated by the light source via the substrate, and the holding member attaches the light guide and the heat radiating member to the reflector, respectively. It comprised so that it might press-contact.

Furthermore, the present invention provides a platen for placing a read document, a light source unit having a light source for illuminating the read document placed on the platen, and reflected light from the read document illuminated by the light source of the light source unit. And a light receiving means for receiving the light. The illumination device is configured as described in any one of claims 1 to 7.

According to the first aspect of the present invention, the reflecting plate forming the pseudo light source is attached to the other end surface of the light guide through an adhesive material having a high light transmittance, so that a predetermined interval is provided on one end surface of the light guide. Like the light source, the adhesive material creates a certain gap between the reflector and the other end surface of the light guide so that the light environment between the light source and the simulated light source is closer, making the light source more A similar simulated light source can be created. Therefore, the illuminating device having this configuration is bright as in the case where the light sources are provided on both end faces of the light guide, and exhibits an excellent effect of obtaining the left and right spectral characteristics as linear light.

Moreover, in the illuminating device according to claim 2 of the present invention, the sheet material is cut in accordance with the outer shape of the other end face of the light guide body and used as a reflection plate, and the reflection sheet is peeled off. By attaching the plate to the other end surface of the light guide, the workability is excellent, and by simply attaching the reflector to the other end surface of the light guide, it is ensured between the reflector and the other end surface of the light guide. A certain gap can be provided, and the above-described effects can be obtained. Furthermore, since the reflection plate is configured such that the sheet-like reflective layer is superimposed on the sheet-like adhesive material, the reflection plate can be processed without being affected by the processing accuracy, and the light amount due to the unevenness of the mirror surface. It is possible to reduce the occurrence of unevenness.

Furthermore, in the illumination device according to the third aspect of the present invention, the light from the light source disposed on the one end face of the light guide is guided by a drop in the amount of light that attenuates when propagating through the light guide. By reducing the amount of light on the other end surface side of the body, the light amount on the other end surface side of the light guide can be increased by inclining the reflecting plate, and an excellent effect is obtained in that the left and right uniform spectral characteristics are obtained as linear light.

Furthermore, in the illuminating device according to claim 4 of the present invention, the light guide in the illuminating device according to claim 1 has a light emission surface formed by a circumferential surface, and is predetermined outside the circumferential region. The reflecting surface is formed at a position separated by a distance, and the light source has one light emitter disposed between the center of the circle forming the circumferential surface and the circumferential surface. Can be made higher than the light quantity at the center, and the light quantity distribution optimal for the illumination apparatus mounted on the optical reduction system image reading apparatus described above can be obtained.

Furthermore, in the illuminating device according to claim 5 of the present invention, the light guide in the illuminating device according to claim 1 has a light emission surface formed of a circumferential surface, and a predetermined area outside the circumferential region. The reflecting surface is formed at a position separated by a distance, and the light source has the first light emitter disposed between the center of the circle forming the circumferential surface and the circumferential surface of the first light emitter. By arranging the light emitters in the circumferential area according to the separation distance of the light scattering surface, it is possible to adjust the light quantity so that the light quantity at both ends is higher than the light quantity at the center part of the light guide. The light amount distribution can be adjusted to be optimal for the illumination device mounted on the optical reduction system image reading device.

In the illumination device according to claim 6 of the present invention, the gap between the light guide and the light source is made uniform by holding the light guide and the light source with the holding member via the reflector. It is possible to achieve the effect of suppressing unevenness in the amount of light.

In the illumination device according to claim 7 of the present invention, the gap between the light guide and the light source can be made uniform by pressing the light guide and the heat radiating member against the reflector. By arranging the light source between the light guide and the light guide in a sealed space and dissipating the heat generated from the light source to the heat sink, it is possible to suppress the occurrence of unevenness in the amount of light and the effect of improving the heat dissipation efficiency. Play.

The illumination device according to claim 8 of the present invention is an image reading device that reads an image by scattering and reflecting light from a light source and irradiating a reading surface with linear light, and reads the light. A light guide having a light scattering surface that scatters in a line direction along the surface, and a light emitting surface that emits light from the light scattering surface toward the reading surface, and is disposed on one end surface of the light guide. A light source and a reflector that causes light of the light emitter to enter the light guide, the light emitter facing the light guide via the reflector, and The other end surface of the light guide body is formed with an inclined surface, and a reflection plate is attached to the inclined surface with an adhesive material, thereby improving productivity and reducing the amount of light at both ends of the light guide body. The amount of light in the center can be made higher than that in the optical reduction system image reading apparatus described above. Optimum light amount distribution in the illumination device for mounting an effect that is obtained.

  As described above, the light irradiated from the exit surface of the light guide to the reading surface has a large amount of light at both ends in the reading line direction and a small amount of light at the central portion, and has a light amount characteristic. Accordingly, by setting the incident positions of the first and second plurality of light emitters to the optimum values, it is possible to irradiate the reading surface with the light amount characteristic suitable for the characteristic (mainly the lens characteristic or the sensor characteristic) of the reading optical system. It becomes possible.

  In addition, the present invention is a method in which a reflecting plate that has been punched in accordance with the outer shape of the other end surface as a reflecting surface is bonded with a double-sided tape, and it is only necessary to manage the reflecting sheet of the reflecting plate to be punched. Even if some skill is required to stick the other end to the other end, the work is easy and excellent in workability, and compared to the conventional method, variation in the amount of reflected light and fluctuation in reflectance due to light leakage, light leakage can be suppressed, As a result, it is possible to provide an illumination device capable of obtaining an appropriate light quantity characteristic.

1 is a cross-sectional view showing an overall configuration of an image reading apparatus according to the present invention. FIG. 2 is a cross-sectional view illustrating a configuration of a reading carriage that reads a document image in the image reading apparatus of FIG. 1. FIG. 2 is a perspective view showing an external structure of a carriage in the image reading apparatus of FIG. 1. The perspective view which shows the external appearance structure which looked at the carriage of FIG. 3 from the downward direction. The top view which shows the external appearance structure which looked at the carriage of FIG. 3 from upper direction. The perspective view which shows the illuminating device mounted in the carriage of FIG. The partial exploded side view of the illuminating device of FIG. The partial exploded perspective view of the illuminating device of FIG. It is a principal part enlarged view in the illuminating device of FIG. 8, (a) is side surface fragmentary sectional view, (b) is the external view seen from the one end light source side of a light guide, (c) is from the other end side of a light guide. External view seen. The principal part enlarged view explaining the state of the reflected light in the light guide in the illuminating device of Fig.9 (a). The top view seen from the light guide body explaining the light source unit in the illuminating device of FIG. FIG. 12 is an enlarged cross-sectional view of the light source unit of FIG. 11. The disassembled perspective view of the light source unit of FIG. It is a figure which shows the structure of the light source and light source board | substrate of the light source unit of FIG. 13, (a) is a top view which shows the light source feed circuit pattern wiring of a light source board | substrate, (b) is sectional drawing of the ZZ surface, (c). FIG. 3 is a plan view showing a terminal pattern of a light source. 11A and 11B are views for explaining the positional relationship between the light source and the light guide in the light source unit of FIG. 11, wherein FIG. 11A is a side view, and FIG. 11B is a position of the light source with respect to the light guide viewed from one light source side of the light guide. (C) is a top view which shows the position of the light source seen from the other end side of the light guide. The plane enlarged view which shows the position of the light source with respect to the light guide of FIG.15 (b). It is a figure for demonstrating the positional relationship of the light source and light guide in the light source unit regarding the other Example corresponding to FIG. 15, (a) is a side view, (b) was seen from the one end light source side of the light guide. The top view which shows the position of the light source with respect to a light guide, (c) is a top view which shows the position of the light source seen from the other end side of the light guide. FIG. 6 is a spectral characteristic diagram showing spectral characteristics of the illumination device in the image reading apparatus of the present invention. 1 is a functional block diagram showing a control system for reading a document image in the image reading apparatus of FIG.

In the following, one embodiment of an image reading apparatus equipped with the illumination device according to the present invention will be described based on FIGS. 1 to 16, another embodiment of the image reading apparatus based on FIG. 17, and the image of the present invention based on FIG. The spectral characteristics of the illumination device in the reading device will be described with reference to FIG. 19 for an image data processing unit that reads a document image of the image reading device.

[One Example of Image Reading Apparatus]
First, an embodiment of an image reading apparatus equipped with an illumination device according to the present invention will be described with reference to FIGS. FIG. 1 shows the overall configuration of the image reading device, FIGS. 2 to 5 show the configuration of a reading carriage mounted on the image reading device, and FIGS. 6 to 10 show the illumination device serving as the light source of the reading carriage. 11 to 16 are for explaining the configuration of the light source unit of the illumination device.

<Overall configuration of image reading device>
FIG. 1 is a cross-sectional view showing the overall configuration of the image reading apparatus. This image reading apparatus is composed of the following image reading unit A and a document feeding unit B mounted thereon.

(Image reading unit A)
The image reading unit A includes a first platen 2 and a second platen 3 in the apparatus housing 1. The first platen 2 and the second platen 3 are made of a transparent material such as glass and are fixed to the top of the apparatus housing 1. The first platen 2 is formed with the maximum size of a usable document that can be manually placed, and the second platen 3 is formed with the maximum width of the usable document so as to read a document that moves at a predetermined speed. Yes. The first platen 2 and the second platen 3 are arranged side by side, guided below by the guide shaft 12 and the rail member GL, and supported in the apparatus housing 1 so as to be movable parallel to the platen surface. A reading carriage 6 reciprocated by Mc is incorporated.

(Original Feed Unit B)
The document feeding unit B is disposed above the first platen 2 and the second platen 3 so as to cover the first platen 2 and the second platen 3, and a lead roller (document feeding means) 21 and a carry-out roller 22 that feed the document sheet to the second platen 3. And. Further, on the upstream side of the read roller 21, a paper feed stacker 23 for stacking and storing original sheets, a paper feed roller 24 for separating and feeding the sheets stacked on the paper feed stacker 23 one by one, and separation feeding A registration roller pair 25 for correcting the skew of the leading edge of the sheet is disposed. Further, a lead sensor S 1 for detecting the leading edge of the original reaching the second platen 3 is provided in the paper supply path 26 for guiding the original sheet from the paper supply stacker 23 to the second platen 3, and the upper surface of the second platen 3. The backup roller 27 is arranged at the same peripheral speed as the lead roller 21, fits the original sheet on the second platen 3, and conveys it to the carry-out roller 22 arranged downstream of the platen. Further, on the downstream side of the carry-out roller 22, a paper discharge stacker 29 arranged in a vertically parallel manner is disposed below the paper discharge roller 28 and the paper feed stacker 23, and the first platen 2 is disposed at the bottom of the paper discharge stacker 29. There is provided a platen cover 5 for pressing and supporting a document sheet placed thereon.

Instead of the backup roller 27, a backup guide may be arranged above the platen. In the image reading apparatus described as the first embodiment described above, the first platen 2 and the second platen 3 are arranged side by side, and the document feeding unit B is mounted thereon. An image reading apparatus in which the two platen 3 is removed and only the first platen 2 is provided, an opening / closing cover is attached instead of the document feeding unit B, and the opening / closing cover covers the first platen 2 may be used.

(Original Fixed Reading Mode = Flat Bed Mode)
The document feeding unit B configured as described above is set on the first platen 2 by the operator selecting the document fixed reading mode, so-called flatbed mode, on the apparatus panel of the image reading unit A or on the screen of the PC. When the original sheet is read, the original sheet is placed on the apparatus housing 1 of the image reading unit A so as to be freely opened and closed, the original feeding unit B is lifted upward, and the first platen 2 is opened. The document sheet is covered with the platen cover 5 of the document feeding unit B, and the reading carriage 6 moves along the guide shaft 12 below the document sheet to perform a reading operation.

(Original scanning mode = sheet-through mode)
Also, the document feeder unit B has a second platen that is transported by the document feeder unit B when the operator selects a document flow scanning mode, so-called sheet-through mode, on the apparatus panel of the image reading unit A or on the screen of the PC. When reading a document sheet flowing over 3, the reading carriage 6 is moved to the reading position of the second platen 3 by the above-described travel driving means 19 and carriage motor Mc and stopped, and is read. I do.

<Configuration of reading carriage>
Next, the reading carriage 6 will be described. 2 is a cross-sectional view showing a configuration of a reading carriage 6 that reads an original image in the image reading unit A of FIG. 1, FIG. 3 is a perspective view showing an external structure of the reading carriage 6, and FIG. 4 shows the reading carriage 6 of FIG. FIG. 5 is a plan view showing the external structure of the reading carriage 6 shown in FIG. 3 as viewed from above.

First, the reading carriage 6 will be described with reference to FIG. The reading carriage 6 includes a unit frame 11 made of a heat-resistant resin and a metal plate, a light source unit 9 (illuminating device) including a pair of a first light source body 9a and a second light source unit 9b, and a light source unit 9 A reflecting mirror 10 composed of first to sixth mirrors 10a to 10f for deflecting reflected light from the original sheet illuminated by the light, and condensing the reflected light from the original sheet reflected by the reflecting mirror 10. A lens 7 and a line sensor 8 (imaging device) disposed in an image forming unit that forms an image with the condenser lens 7 are mounted. The image data output as an electrical signal from the line sensor 8 is electrically connected to an image processing unit (data processing board) to be described later by a data transfer cable (not shown) so as to be transferred to the image processing unit.

As shown in FIGS. 2 and 3, the unit frame 11 has a reading opening 34 corresponding to the reading line width W of the original sheet. The reading opening 34 reads the original sheet irradiated with light from the light source unit 9. The line sensor 8 can receive the reflected light reflected from the surface. The unit frame 11 is movably supported by the guide shaft 12 and the rail member GL so as to reciprocate with a predetermined stroke.

The light source unit 9 will be described in detail as a lighting device, which will be described later. The light source unit 9 is composed of a light source that irradiates linear light along the reading opening 34 of the unit frame 11, and is integrally attached to the unit frame 11. Then, the reading light is applied to a document sheet on a platen described later.

The reflection mirror 10 is appropriately composed of a plurality of sheets so as to form a predetermined optical path length, and in the case of this embodiment, it is composed of six sheets. Reflected light from the image reflected on the original surface of the original sheet by the first mirror 10a is reflected toward the second mirror 10b, and the reflected light is reflected by the second mirror 10b and reflected toward the third mirror 10c. The reflected light is reflected by the third mirror 10c and again reflected toward the second mirror 10b, the reflected light is reflected toward the fourth mirror 10d, and the reflected light is reflected by the fourth mirror 10d, and the reflected light is reflected. The light is reflected toward the fifth mirror 10e. Finally, the reflected light reflected by the fifth mirror 10e is guided to the sixth mirror 10f, and the reflected light reflected by the sixth mirror 10f is converted into the condenser lens 7. To guide. The reflected light of the document image is not limited to such an optical path formation, and it is possible to form an optical path using, for example, first and second reflection mirrors.

The condensing lens 7 is composed of one or a plurality of imaging lenses, and forms an image on the line sensor 8 of the reflected light reflected from the original surface of the original sheet transmitted through the reflecting mirror 10.

The line sensor 8 is composed of a photoelectric conversion sensor such as a CCD, and receives and photoelectrically converts the reflected light of the document image sent from the condenser lens 7. The line sensor 8 is composed of a color line sensor, and sensor elements constituting R (Red), G (Green), and B (Blue) pixels are arranged in three lines in a line. The line sensor 8 having such a configuration is attached to the sensor circuit board 45, and the sensor circuit board 45 is fixed to the unit frame 11.

<Reading carriage support mechanism>
As shown in FIGS. 3 to 5, the reading carriage 6 has one end pivotally supported by the guide shaft 12 by a bearing disposed in the apparatus housing 1, and the other end of the reading carriage 6 is slidable on the rail member GL. The device housing 1 is supported so as to be reciprocally movable. The carriage support mechanism composed of the guide shaft 12 and the rail member GL is attached to the apparatus housing 1 in parallel with each other and to both the first platen 2 and the second platen 3 in parallel. The platen 2 and the second platen 3 are opposed to the plane and are configured to reciprocate stably in parallel.

<Scanning carriage movement mechanism>
The carriage movement mechanism of the reading carriage 6 includes a carriage motor Mc composed of a drive motor such as the pulse motor and the DC motor with an encoder shown in FIG. 1, a wire that rotates by the reciprocating rotation of the carriage motor Mc, a timing belt, and the like. The pulling member 17 and a pair of pulleys 46a and 46b rotatably supported by the apparatus frame 1 are configured. A carriage motor Mc that can be rotated forward and backward is connected to the one pulley 46b, a traction member 17 is stretched between the pair of pulleys 46a and 46b, and the reading carriage 6 is connected to the traction member 17 to move the carriage. The mechanism is configured.

<Reading operation of reading carriage>
The reading carriage 6 connected to the carriage moving mechanism uses a shading plate as a light source for adjusting a light amount characteristic (not shown) disposed above the home position HP, that is, a position corresponding to the home position HP shown in FIG. Depending on the mode selected from the home position HP, the unit 9 is stopped at the position where the light is illuminated. In the document flow reading mode, the reading carriage 6 is shown at the position indicated by the solid line in FIG. Is moved to the position of the reading carriage 6 indicated by the two-dot chain line.

<Configuration of lighting device>
Next, an illumination device that is attached to the above-described reading carriage 6 and used as the light source unit 9 will be described with reference to FIGS. 6 is a perspective view showing the lighting device mounted on the carriage of FIG. 3, FIG. 7 is a partially exploded side view of the lighting device of FIG. 6, FIG. 8 is a partially exploded perspective view of the lighting device of FIG. FIG. 9 is an enlarged view of a main part of the illumination device of FIG. 8, (a) is a side sectional view, (b) is an external view as viewed from one light source side of the light guide, and (c) is the other end side of the light guide. FIG. 10 is a main part enlarged view for explaining the state of reflected light in the light guide in the illumination device of FIG. 9A.

The light source unit 9 that is this illumination device irradiates linear light along a reading line that forms a reading width in the main scanning direction orthogonal to the reading surface R shown in FIG. The light source unit 9 is composed of a first light source body 9a and a second light source unit 9b shown in FIG. 2, and each of the first light source body 9a and the second light source unit 9b is a unit frame 11 of the carriage 6 shown in FIG. Are accommodated in a first accommodating portion 13a and a second accommodating portion 13b formed in a light source accommodating portion (light guide support frame) 13 supported by the first and second accommodating portions. As shown in FIG. 7, the first light source body 9a and the second light source unit 9b are respectively composed of a light source unit La and a light guide body 30 that support the light emitting body 40. Hereinafter, the configuration and guide of the light source unit La will be described. The configuration of the light body 30 will be described in detail.

<Configuration of light source unit>
First, the configuration of the light source unit La will be described in detail with reference to FIGS. 8 and 11 to 14. 11 is a plan view of the light source unit La in the illumination device of FIG. 8 as viewed from the light guide side, FIG. 12 is an enlarged sectional view of the light source unit La of FIG. 11, and FIG. 13 is an exploded perspective view of the light source unit La of FIG. FIGS. 14 and 14 are views showing the structure of a light source substrate to which the light emitter 40 of the light source unit La in FIG. 13 is electrically attached. FIG. 14 (a) is a plan view showing light source power supply circuit pattern wiring of the light source substrate. Sectional drawing of the ZZ surface, (c) is a top view which shows the terminal pattern of a light source.

As shown in FIG. 8, the light source unit La is composed of a heat radiating member 14, a heat conductive sheet 15, and a circuit board 16, and the circuit board 16 includes a first light emitter as shown in FIG. A lens cap 43 is attached to each of the (white LED) 41 and the second light emitter (white LED) 42, and a reflector 49 is put on the lens cap 43. In addition, an insulating mylar 47 that insulates portions other than those covered by the reflector 49 is provided. In the following, description of individual parts and unit assembly will be described.

* Description of Light Emitter First, the light emitter 40 will be described with reference to FIGS. The light emitter 40 includes two light emitting elements, a first light emitter 41 and a second light emitter 42, and is mounted on the circuit board 16. In this embodiment, the light emitting element is composed of a white LED chip. Further, as shown in FIG. 14C, the luminous body 40 forms an anode 40a and a cathode 40b for supplying power, and a thermal pad 40c for heat dissipation.

* Description of Circuit Board The circuit board 16 on which the light emitting body 40 is mounted is fixed to the heat radiating member 14 via the heat conductive sheet 15 as shown in FIG. 14B, and the light emitting body 40 is mounted on the circuit board 16. Has been. As shown in FIG. 14 (a), the circuit board 16 has a wiring pattern 16a-1 made of a material having high conductivity such as copper, silver, gold, etc. for emitting and energizing the light emitter 40 on the surface of the circuit board. 16a-5 are formed, and the back surface of the substrate is covered with a heat conductive layer 16b-2 having a particularly high thermal conductivity such as copper, silver, and aluminum, and a part of the heat conductive layer is formed on the light emitting body 40. The protrusion 16b-1 is formed on the substrate surface so as to be in direct contact with the light emitting source. The circuit board 16 has a particularly high thermal conductivity such as copper, silver or aluminum on the back surface of the circuit board 16 in a state where a through hole for forming the protrusion 16b-1 is previously formed in an insulating board made of an epoxy material. After forming the heat conductive layer 16b-2 and the protrusion 16b-1 by injection molding of the heat conductive material, a layer made of a material having high conductivity such as copper, silver, gold or the like is formed on the substrate surface. Is formed by etching so as to leave the wiring patterns 16a-1 to 16a-5 and the protrusions 16b-1. The circuit board 16 has the light emitter 40 mounted thereon, and the thermal pad 40c of the light emitter 40 and the protruding portion 16b-1 protruding from the back surface of the substrate are in pressure contact with each other, so that the heat generated when the light emitter 40 is turned on. Is radiated to the heat conductive layer 16b-2 on the back surface of the substrate through the protrusion 16b-1 in contact with the thermal pad 40c.

The circuit board 16 may be formed in multiple layers. In this case, it is desirable that the heat conductive layer 16b-2 on the back surface of the circuit board and the projecting part 16b-1 projecting on the surface of the board be connected so as to maintain high heat conduction. Moreover, you may comprise so that the heat | fever of the light-emitting body 40 may be conducted to the thermal radiation member 14 through the anode 40a and the cathode 40b.

* About the heat conductive sheet The heat conductive sheet 15 is an elastic sheet material made of an insulating synthetic resin having high thermal conductivity made of, for example, a thermoplastic elastomer or a non-silicone thermoplastic resin, and having high elasticity. As shown by the dotted line in FIG. 14B, the heat of the light emitting body 40 interposed between the circuit board 16 and the heat radiating member 14 to be described later and radiated to the heat conductive layer 16b-2 of the circuit board 16 is dissipated. Is provided for efficient conduction.

* Regarding the heat radiating member The heat radiating member 14 is made of a metal material having a high thermal conductivity such as an aluminum alloy. In order to increase the surface area, for example, a plurality of protruding plate-like fins are formed as shown in FIG. The heat of the luminous body 40 conducted through the above-described heat conductive sheet 15 is efficiently radiated.

* Insulation Mylar As shown in FIG. 8, an insulation mylar 47 is provided on the surface of the circuit board 16 on the light guide 30 side. The insulating mylar 47 insulates the circuit board 16 from contact with the metal members constituting the carriage 6 and protects the surface of the circuit board 16 from damage to the substrate surface.

* Further, as shown in FIGS. 8 to 13, in order to make the light from the illuminant 40 enter the light guide 30 without loss, the reflectors of the first illuminant 41 and the second illuminant 42 are used. A reflector 49 that restricts the characteristics within 90 ° is provided. One reflector 49 is provided for each light emitter. The reflector 49 is made of a material having a high reflectivity obtained by evaporating a metal such as aluminum on a plastic material, and has an umbrella shape extending from the light emitting body 40 toward the light guide body 30. At this time, the umbrella-shaped portion may be formed with a curved surface or a flat surface.

* Similarly to the holding member, the holding member 48 shown in FIG. 8 presses and urges the heat radiating member 14 and the flange 30N provided at the one end 30L of the light guide 30 through the reflector 49 as shown in FIG. In addition, the gap between the light guide 30 and the light emitter 40 is regulated to be constant. Accordingly, the holding member 48 is formed of a spring member having rigidity such as a metal having a spring property, and pulls the light guide 30 toward the heat radiating member 14 and pulls the heat radiating member 14 toward the light guide 30. .

[Configuration of light guide]
Next, the light guide will be described based on FIGS. 9 and 10 described above and FIGS. 15 and 16 newly. FIGS. 15A and 15B are diagrams for explaining the positional relationship between the light source and the light guide in the light source unit of FIG. 11, where FIG. 15A is a side view and FIG. 15B is a light guide viewed from one light source side of the light guide. The top view which shows the position of the light source with respect to a body, (c) is a top view which shows the position of the light source seen from the other end side of a light guide, FIG. 16 shows the position of the light source with respect to the light guide of FIG.15 (b). It is a plane enlarged view.

The light guide 30 is a rod-like light-transmitting member having a length corresponding to the reading width (reading line width) W as shown in FIGS. 9 and 10, and is rich in light-transmitting properties such as transparent acrylic resin and epoxy resin. It is made up of materials. As shown in FIGS. 15 and 16, the cross-sectional shape is formed so that the light scattering surface 32 and the light emitting surface 33 face each other, the light emitter 40 is disposed on one end surface 30L, and the other end surface 30R is disposed on the other end surface 30R. A reflective plate 50 having a mirror-finished surface and a reflective layer having a high reflectivity such as aluminum or silver is attached by an adhesive (double-sided tape) 60 having a light transmittance of 90% or more so as to form a reflective surface. ing. Further, as shown in FIG. 9, the light scattering surface 32 and the light emitting surface 33 are arranged to face each other with a length of the reading line width W substantially in parallel with a distance Ld.

<Description of light scattering surface>
The light scattering surface 32 is surface-processed so as to diffusely reflect the light that is formed on the uneven surface by coating, etching, or molding with a reflective paint such as urethane-based white ink. The surface processing is not performed on the side close to the one end face 30L of the light guide 30 as shown in FIGS. 9 and 10, and from the place where a certain distance has passed from the one end face 30L to the other end face 30R. Further, the base end portion on the one end surface 30L side is longer than the base end portion of the reading line width W on the one end surface 30L side as shown in FIG. This is because when the reading line width W and the surface processed portion have substantially the same length, the peak of the light amount on the 30L side of the reading line width W is shifted to the 30R side, and the light amount at the end on the 30L side is insufficient. For this reason, the light amount distribution is set long in advance so as to be an appropriate value.

Further, the light emitting surface 33 of the light guide 30 is formed as a circumferential surface as shown in FIG. The circumferential surface is formed with a radius of 3.7 mm ± 0.1 mm, and the center P1 of the circumferential surface is provided on a normal line hx that is the center of the illumination optical path. The light scattering surface 32 is located outside the circumferential region, and the position is set at a position of 8.46 mm ± 0.1 mm from the light emitting surface 33 on the normal hx.

<Description of reflector>
The reflective plate 50 and the adhesive material 60 are formed as a single sheet-like material, and the adhesive material 60 is made of an acrylic sheet-like material having a light transmittance of 90% or more. A reflection plate 50 serving as a sheet base material having the above-described reflection surface formed on the front surface side and a sheet material in which a release sheet provided with a release surface (not shown) on the back surface side are stacked. In the present embodiment, the thickness of the reflection plate and the sheet material of the adhesive material is 25 micrometers. However, if the light transmittance can be ensured to be 90% or more, the thickness can be 25 micrometers or more. Then, the release sheet is peeled off from the adhesive material 60 from the sheet material that has been punched in conformity with the outer shape of the other end surface 30R of the light guide, and the reflection plate 50 to which the adhesive material 60 is attached is attached to the other end surface of the light guide. By attaching to 30R, the reflector attaching operation can be easily performed with good workability. Moreover, the adhesive material 60 is reliably provided between the reflector 50 and the other end surface 30R of the light guide by simply attaching the reflective plate 50 to which the adhesive material 60 is attached in advance to the other end surface 30R of the light guide. A constant gap can be provided on one end face of the light guide at a predetermined interval with the thickness of the material, and the reflector 50 is in a state close to the light environment of the light source. Thus, by creating a pseudo light source that is more similar to the light source, it is possible to obtain bright and uniform left and right spectral characteristics as linear light as in the case where the light sources are provided on both end faces of the light guide.

Further, as shown in FIG. 9, the reflection surface of the other end surface 30 </ b> R can correct the above light quantity characteristic by adjusting the angle by an angle θ in the length direction with respect to the normal direction hx of the light scattering surface 32. It becomes. That is, as shown in FIG. 9, when the angle of the reflecting surface is tilted by plus θ in the clockwise direction, the amount of light at both ends of the main scanning direction increases. Conversely, when tilted by minus θ in the counterclockwise direction, the amount of light at both ends of the main scanning direction becomes By reducing this angle and setting this angle when designing the light guide 30 in advance, it becomes possible to easily match the characteristics of the condenser lens 7. The optimum value is about 5 °. Note that the reflecting surface of the other end surface 30R is also inclined with respect to the light guide side surface 30S in order to improve convenience when the light guide 30 is removed from the mold.

Further, the light guide 30 has a protrusion 30P as shown in FIG. The protrusion 30P is a bowl-shaped protrusion protruding from the cross section as shown in the figure. The protruding portion 30P is not provided in the vicinity of the one end portion 30L, and is located between the base end portion where the surface processing of the light scattering surface 32 is performed and the base end portion of the reading line width W. And provided between the other end 30R. This is to prevent the projection 30P from extending to the one end face 30L and causing the light to be irregularly reflected by the projection 30P and affecting the spectral characteristics, and to prevent the amount of reflected light from attenuating outside that portion. is there.

Therefore, the light of the light emitting body 40 introduced into the light guide 30 is diffused in a predetermined direction by the light scattering surface 32, and the light introduced into the light emitting surface 33 is reflected inside when the angle exceeds a predetermined critical angle, When it is below the critical angle, it is emitted to the outside. The light indicated by the arrow ha in FIG. 8 is reflected in the light guide 30 and dispersed in the reading line width W direction, and the light indicated by the arrow hb is emitted from the light emitting surface 33 to the reading surface R. Although not shown, light is incident in a spherical direction (360-degree direction; the illustrated one is a 60-degree wide-angle direction) from a light emitter 40, which will be described later, and irradiates the light scattering surface 32 and the light emitting surface 33.

In addition, light that has repeatedly reflected in the light guide 30 and reaches the other end surface 30R is reflected by the surface of the other end surface 30R, returned to the light emitter 40 side, and similarly reflected by the light scattering surface 32 and indicated by an arrow ha. Is emitted from the light emitting surface 33 to the reading surface R. Using this characteristic, the arrangement of the light emitter 40 with respect to the one end surface 30L is adjusted, the light emitted from the light emitting surface 33 on the one end surface 30L side to the reading surface R is lowered, and the light reflected on the surface of the other end surface 30R is reflected. By increasing the light amount on the one end surface 30L side, the light amount on the other end surface 30R side can be increased, the light amount emitted to the reading surface R is made uniform, and when using the optical reduction system type condensing lens 7 It is possible to adjust the light amount close to the light amount distribution of the cosine fourth law that depends on the lens characteristics.

<Arrangement of light emitter and light guide>
Next, the positional relationship between the light emitter 40 and the light guide 30 will be described with reference to FIGS. 13 and 16. The first light emitter 41 and the second light emitter 42 constituting each light emitter 40 shown in FIG. 13 are located at the position P1 on the normal line (outgoing light path direction) hx of the light scattering surface 32 described above with reference to FIG. The first light emitters 41 and the second light emitters 42 are arranged at the position P2. The first light emitter 41 is disposed at a distance Ld1 from the light scattering surface 32, and the second light emitter 42 is disposed at a distance Ld2. An offset amount dx is formed between the light emitters 41 and 42. In the present embodiment, the first light emitter 41 disposed at a position close to the light scattering surface 32 and the second light emitter 42 disposed at a position close to the light exit surface 33 are each composed of two light emitting elements. In order to further diffuse light, a lens 43 is provided between the light emitting element and the light guide 30. The first light emitter 41 and the second light emitter 42 are disposed on the normal line hx. In other words, the first light emitter 41 is arranged at a distance Ld1 and the second light emitter 42 is arranged at a distance Ld2 (Ld1 <Ld2) with respect to the light scattering surface 32.

<Gap between light emitter and light guide>
The circuit board 16 on which the light emitting element is mounted is disposed with a gap d between the light emitting surface and the one end surface 30L of the light guide 30. The gap d is preferably in the range of 0.1 millimeters to 0.55 millimeters. FIG. 9 shows an arrangement structure in a state where the light emitters 40 (41, 42) are mounted on the circuit board 16. The light emitter 40 (41, 42) is composed of a planar light emitting element, and is composed of a white LED. Furthermore, in order to increase the total amount of light, a similar light emitter 40 (41, 42) may be disposed instead of the reflective paint on the other end surface 30R. Further, in this case, the first light emitter 41 and the second light emitter 42 enter light from one end face 30 </ b> L of the light guide 30 from different positions between the light scattering surface 32 and the light emitting surface 33. At the same time, the first light emitter 41 and the second light emitter 42 are arranged at a distance from each other in the direction of the outgoing light path from the light emitting surface 33 toward the reading surface R (indicated by an arrow hx in FIG. 5).

<Assembly of light source unit>
Next, assembly of the light source unit will be described with reference to FIG. First, the light emitting body 40 (41, 42) is mounted on the circuit board 16, and the lens cap 43 is mounted. The circuit board 16 is integrally attached by screwing in a state where the circuit board 16 is in close contact with the heat radiating member 14 (heat sink) via the heat resistant sheet 15 (heat resistant resin plate). Then, the heat dissipation member 14 (heat sink) to which the circuit board 16 is attached and the light guide 30 are held by the holding member 48 via the reflector 49, and the circuit board 16 is pressed into contact with one surface of the reflector 49. The light guide 30 is attached to the unit frame 11 of the carriage 6 in a state where the light guide 30 is pressed against the surface of the carriage 6.

[Other Embodiments of Image Reading Apparatus]
Next, another embodiment of the above-described lighting device will be described. FIGS. 17A and 17B are views for explaining the positional relationship between the light source and the light guide in a light source unit according to another embodiment corresponding to FIG. 15, where FIG. 17A is a side view, and FIG. The top view which shows the position of the light source with respect to the light guide seen from the side, (c) is a top view which shows the position of the light source seen from the other end side of the light guide. The difference from the light source unit shown in FIG. 15 is that the arrangement and brightness of the light source and the light guide are different depending on whether the light emitting source 40 is composed of one light emitting element or two light emitting elements. However, the basic functions are almost the same.

In this embodiment, as shown in FIG. 17A, in this embodiment, a light emitting source 40 composed of one light emitting element facing a certain gap is arranged on one end face 30L of the light guide 30. The light source 40 is disposed at the light source position P2 shown in FIG. 16 described above. The spectral characteristics at that time will be described later with reference to FIG. As in FIG. 15, only one light source unit that is received in a pair in the front and rear direction in the sub-scanning direction with respect to the center of the reading surface R is displayed as shown in FIG.

Next, the spectral characteristics of the illumination device in the image reading apparatus of the present invention will be described based on the spectral characteristics diagram of FIG. In the figure, the spectral characteristics indicated by P1 to P4 indicate the spectral characteristics obtained when the light source 40 is disposed at the positions P1 to P3 shown in FIG. First, the spectral characteristic indicated by P1 indicates the spectral characteristic obtained when the light emitting source 40 composed of one light emitting element (white LED) is arranged at the position P1 shown in FIG. 16, and the spectral characteristic indicated by P2 is FIG. 16 shows the spectral characteristics of the other embodiment shown in FIG. 17 obtained when the light emission source 40 is arranged at the position P2 shown in FIG. 16, and the spectral characteristics shown by P3 show the light emission source 40 in FIG. The spectral characteristic obtained when it arrange | positions in the position of P3 shown by is shown. The spectral characteristic indicated by P4 is obtained when the light source 40 (41, 42) composed of two light emitting elements (white LEDs) is arranged at the positions P2 and P3 shown in FIG. The spectral characteristics of the first embodiment shown in FIGS. 2 to 15 are shown. Looking at this spectral characteristic, since the illumination device of the image reading apparatus having the contact optical system described above requires a substantially uniform spectral characteristic, a light emitting source composed of one light emitting element. By arranging 40 at a position P1 shown in FIG. 16, an illumination device having ideal spectral characteristics can be obtained. On the other hand, in the case of an illumination device of an optical reduction system image reading device that is affected by the cosine fourth law by a condensing lens, the light amount distribution needs to be higher at both end portions than at the central portion. In the case where reading is possible even when the total amount of light is relatively low, an illuminating device having ideal spectral characteristics can be obtained by arranging a light emitting source 40 composed of one light emitting element at a position P2 shown in FIG. If the light source 40 (41, 42) composed of two light emitting elements cannot be read unless the total light quantity is relatively high, the light source 40 (41, 42) composed of two light emitting elements is placed at the position P2 shown in FIG. An illuminating device having ideal spectral characteristics can be obtained by disposing the two light emitting sources 42 and disposing the first light emitting source 41 at the position P3.

[Configuration of image reading control system]
Next, an outline of a control system for reading a document image in the image reading apparatus shown in FIG. 1 will be described based on FIG. FIG. 19 is a functional block diagram showing a control system for reading a document image in the image reading apparatus. In FIG. 19, a portion surrounded by a two-dot chain line corresponds to the reading carriage 6 and is surrounded by a thin line. The portion corresponds to the control board S provided in the image reading unit A. The operation of the image reading apparatus by each basic functional block is as follows. The control unit CPU of the control board S drives the motor driving means S-MC, the light source lighting means S-La, and the sensor driving means S-CCD. Then, the sensor driving means S-CCD causes the line sensor 8 to read the original sheet. That is, with the reading carriage 6 moved or stopped as necessary by the motor driving means S-MC, the original sheet is illuminated while the light source 40 is appropriately turned on by the light source lighting means S-La, and the reflected light from the original is reflected. An image is formed on the line sensor 8 and photoelectrically converted to accumulate charges. The output signal from the sensor 16 is amplified by the amplifier circuit AMP and then converted into a digital image signal by the A / D converter. The image signal digitized by the A / D converter is subjected to image processing such as shading correction, digital gain adjustment, and digital black correction using shading data stored in the RAM in the image processing means. Thereafter, the digital image signal is stored in a line buffer and transferred to an external device such as a personal computer PC via an interface. These are all performed by the control unit PC controlling each functional block based on an instruction from the driver means of the external device.

[Light source control configuration]
The control of the light source unit 9 by the light source lighting means S-La will be described. As shown in FIG. 9, the first light source body 9a and the second light source unit 9b irradiate light onto the reading surfaces R of the first platen 2 and the second platen 3, and use diffusely reflected light reflected from the read original. Yes. The light source unit 9a (9b) is not necessarily composed of two light sources as shown in the figure, and may be composed of one or three or more light sources. In this case, in the document feeding unit B described later, the speed of the document traveling on the second platen 3 is set higher than the speed at which the carriage 6 moves along the first platen 2.

That is, the reading speed of the second platen 3 is higher than the reading speed of the first platen 2. For this reason, it is preferable that the second platen 3 is higher than the first platen 2 in the amount of light applied to the document.

Accordingly, when the carriage 6 is positioned on the first platen 2, the first light guide 30a is turned on, and when the carriage 6 is positioned on the second platen 3, the first light guide 30a and the second light guide 30b are turned on.

[Other Embodiments]
As described above, in the illumination device of the present invention described as the embodiment of the illumination device that can be used for the image reading device based on FIGS. 1 to 19, the illumination device is used as a cause of the occurrence of light spot in the image read by the image reading device. Illumination spots due to variations in the light quantity distribution characteristics of the linear light source caused by fluctuations in the light source mounting position with respect to the light guide to be configured are regarded as one of the factors.
An illumination device that scatters and reflects light from a light source to irradiate a reading surface with linear light, the light scattering surface scattering light from the light source in a line direction along the reading surface, and the light scattering surface. And a light source disposed on one end surface of the light guide, and the light source is provided on one end surface of the light guide. A pseudo light source is formed by arranging a reflection plate on the entire surface of the other end surface of the light guide with a predetermined thickness of an adhesive having a high light transmittance. The reflecting plate and the light guide are, like the light source disposed at a predetermined interval on one end surface of the light guide, between the reflecting plate and the other end surface of the light guide by the adhesive material. By creating a certain gap, the light environment between the light source and the simulated light source becomes closer, and a simulated light source more similar to the light source can be created. Come. Therefore, the illuminating device having this configuration is bright as in the case where the light sources are provided on both end faces of the light guide, respectively, and exhibits the excellent effect of obtaining the left and right uniform spectral characteristics as linear light. However, the present invention may have the following structure.

[Additional explanation of new matter]
The supplementary explanation will be given again for the new matter of the illumination device according to the present invention described as the illumination device of the image reading apparatus.

<Gap retention between light guide and light source by reflector>
First, it supplements about the gap maintenance of a light guide and a light source. As shown in FIG. 9A, an end face (30a, 30b) that captures light, a diffuse reflection surface (32) that diffusely reflects light captured from the end faces (30a, 30b), and a diffuse reflection surface (32). A light guide (30) having a light exit surface (33) for emitting diffusely reflected light toward an irradiation surface (R: see FIG. 2), and at least one end surface (30a, 30) of the light guide (30) In a lighting device (9) comprising a light source (40) facing 30b), a reflecting surface (9a, 30b) that reflects light from the light source (40) toward one end face (30a, 30b) of the light guide (30). 9b), the light guide (30) has a flange (30N) that abuts the reflector (49) on one end face (30a, 30b) of the light guide (30), and the light source (40) Mounted on the circuit board (16) on which the light source is mounted, the reflector (4 ) Is sandwiched between the collar (30N) of the light guide (30) and the circuit board (16), and is held at a predetermined interval between the light source (40) and the light guide (30), so that the light source is reflected by the reflector. The gap between the light source and the light guide can be defined, the predetermined gap between the light source and the light guide is not changed, and illumination unevenness can be suppressed. By using this illumination device as a light source unit of the image reading device, no unevenness in the amount of light occurs in the read image.

The light guide (30) has a flange (30N) that abuts the reflector (49) on one end face (30a, 30b), and the light source (40) is mounted and attached to the circuit board (16). The reflector (49) is sandwiched between the collar (30N) of the light guide (30) and the circuit board (16), and is held at a predetermined interval between the light source (40) and the light guide (30). The collar portion of the light guide supports the plane of the reflector over a wide range, and the circuit board on which the light source is mounted and the light guide can be reliably positioned and held via the reflector.

Moreover, the holding member (48) which clamps a reflector (49) with the collar part (30N) of a light guide (30), and a circuit board (16) is provided. As described above, the holding member (48) includes a heat radiating member (14) for screwing the circuit board (16) on which the light source (40) is mounted to the unit frame (11) via the heat resistant sheet (15). The gap (30N) between the light guide (30) housed in the frame (13) that forms the light source housing that houses the light guide (30) supported by the unit frame (11). Hold it. Then, the holding member (48) holds the circuit board (16) and the light guide (30) in pressure contact with the reflector (49), so that the light source (40) and the light guide (30), which are the cause of the illumination spots. And the gap can be kept constant without variation.

In the embodiment in which the gap between the light source and the light guide is defined by the reflector, the plane of the circuit board on which the light source is mounted is arranged on one of the left and right planes of the reflector, and the plane composed of one end surface of the light guide is formed on the other side. The structures are in direct contact with each other, but the following structures may be used.

One of the structures is a structure in which a thin insulating mylar is sandwiched between the reflector and the circuit board on which the light source is mounted, because the reflector surface is coated with a metal film having good reflection efficiency such as aluminum or silver. A structure in which a thin light-shielding mylar is sandwiched in order to suppress variation in light of the light source narrowed down by the reflector may be used.

Moreover, although each surface contact | abutted with a reflector is formed in the plane, it does not need to be a plane. For example, when one of the abutting surfaces has an uneven shape, the other may have an inverted uneven shape. Further, when one of the abutting surfaces has a curved surface shape, the other may have an inverted curved surface shape.

Further, when the light irradiation surface of the light source mounted on the circuit board is wide and flat, the light source itself may be in contact with the reflector.

Moreover, even if it is the structure which formed the reflector itself integrally as a part of a light source or a light guide, the gap of a light source and a light guide may be prescribed | regulated by the reflector of this invention.

Furthermore, in the above-described embodiment, a light source is arranged at one end of the light guide, and a reflector serving as a pseudo light source is arranged at the other end, but the same is applied to the other end of the light guide to increase the absolute light quantity. When the light source is disposed in the structure, the reflector is naturally disposed on the other surface of the light guide.

<Positioning of the light source facing the light guide>
Next, it supplements about positioning of the light source which opposes a light guide. As shown in FIG. 10, both the light guide (30) and the circuit board (16) have one common reference surface (11s), and the diffuse reflection surface (32) of the light guide (30) is the common reference surface. The circuit board (16) is positioned from the common reference plane (11s), and the light source (40) is one of the light guides (30), held at the first position (d3) positioned from the surface (11s). The positioning structure is arranged at the second position (d2) facing the end faces (30a, 30b). That is, the diffused reflection surface (32) of the light guide (30) is positioned from the common reference surface (11s) to the first position (d3), so that the light guide is attached from the common reference surface (11s). A reference position (d4) is determined. At the same time, the light source (40) mounted on the circuit board (16) is mounted on the light guide (30) by attaching the circuit board (16) on which the light source (40) is mounted to a predetermined position on the common reference plane (11s). The light source mounting reference position (d2) and the light guide mounting reference position (d4) from the common reference plane (11s) are arranged at the second position (d2) facing the one end face (30a, 30b). It can be easily matched, and variation in the light source mounting position (position relative to the normal direction of the optical axis) facing the end face of the light guide can be minimized, and a predetermined gap between the light guide and the light source In addition to the adjustment of lighting, it can suppress illumination spots.

The common reference plane (11s) is provided on the unit frame (11) that constitutes the lighting device (9), and the light guide (30) is a frame that forms a light source accommodating portion supported by the unit frame (11). (13) The diffused reflection surface (32) of the light guide (30) is held at the first position (d3) positioned from the common reference surface (11s) through the frame (13). By using the unit frame as a common reference plane by matching the light source mounting reference position with the light guide mounting reference position, the light source mounting position facing the end surface of the light guide (relative to the normal direction of the optical axis) The device is easy to assemble without adjusting the position.

Further, the common reference plane (11s) is provided in the unit frame (11) constituting the illumination device (9), and the unit frame (11) has positioning portions (11a, 11b) for positioning the circuit board (16). The circuit board (16) is formed and provided with positioning support parts (16a, 16b) supported by the positioning parts (11a, 11b) of the unit frame (11), thereby simply positioning the circuit board (16a, 16b). 16b) is attached to the positioning part (11a, 11b) of the unit frame using the light guide attachment reference, and the light source attachment position (position relative to the normal direction of the optical axis) facing the end face of the light guide is uniform. Can be combined, and the device assembly can be remarkably improved.

<Arrangement of the light source facing the light guide>
Next, it supplements regarding arrangement | positioning of the light source facing a light guide. As shown in FIGS. 16 and 17, the end surfaces (30a, 30b) that capture light, the diffuse reflection surface (32) that diffusely reflects the light captured from the end surfaces (30a, 30b), and the diffuse reflection surface (32). A light guide (30) including a light exit surface (33) for emitting diffusely reflected light toward an irradiation surface (R: see FIG. 2), and at least one end surface (30a, 30b) of the light guide (30) ), The light emitting surface (33) of the light guide (30) is formed with a circumferential surface (radius r), and the diffuse reflection surface (32) is the circle. It is disposed at a position where an optical axis normal (hx) exiting from the light exit surface (33) passes through the center (P1) of the circle forming the peripheral surface (radius r), and is mounted on the circuit board (16). The light source (40) is on the optical axis normal (hx) of the diffuse reflection surface (32) and the center of the circle ( 1) is arranged at the first light source mounting position (P2) displaced toward the light exit surface (33) with respect to 1), and the light source is located between the center of the circle formed by the circumferential surface and the light exit surface. The light quantity at both ends of the light guide can be made higher than the light quantity at the central part, and the optimal light quantity distribution for the illumination device mounted on the optical reading system image reading apparatus described above. Can be obtained.

Moreover, as shown in FIG. 9, the light emission surface (33) of the light guide (30) is formed of a circumferential surface (radius r),
The diffuse reflection surface (32) is disposed at a position where an optical axis normal line (hx) exiting from the light exit surface (33) passes through the center (P1) of the circle forming the circumferential surface (radius r). The light source (40) mounted on the circuit board (16) is composed of the first and second light sources, and the first light source (40) is the optical axis normal (hx) of the diffuse reflection surface (32). The second light source (40) is arranged at a first position (d3) displaced toward the light exit surface (33) with respect to the center (P1) of the circle, and the second light source (40) has its optical axis normal (hx) It is arranged at the second position (d2) which is displaced on the diffuse reflection surface (32) side with respect to the center (P1) of the circle, and the light quantity is increased nearly twice and the light is guided. The amount of light at both ends of the body can be made higher than the amount of light at the center, and an optimum light amount distribution can be obtained for an illumination device mounted on an optical reduction system image reading device. Only the without optimal added document by bright illumination to the image reading apparatus of a so-called sheet-through mode equipped for reading while feeding automatically, can speed up the image reading speed.

In addition, regarding the arrangement of the light source facing the light guide, the following structure may be used.

First, the light source facing at least one end surface of the light guide with a predetermined interval is a light source facing the one end surface of the light guide with a predetermined interval in the embodiment shown in FIGS. 9 and 10 described above. However, instead of this reflecting plate, a new light source may be provided with the same structure as the light source on the one end surface of the light guide.

In addition, by adopting a configuration in which the position of the second light source positioned with respect to the first light source as a position reference can be adjusted, the spectral characteristics can be adjusted by finely adjusting the position with respect to the light amount deterioration due to the temporal change of the light source. The initial appropriate state can be obtained.

<Description of pseudo light source>
Next, the pseudo light source will be supplemented. As shown in FIG. 9A, the illumination device irradiates linear light onto the irradiation surface (R) serving as a reading surface by scattering and reflecting the light from the light source (40), and the light from the light source (40) is irradiated. A diffusion reflection surface (32) that forms a light scattering surface that scatters in a line direction along the irradiation surface (R), and light emission that emits light from the diffusion reflection surface (32) toward the irradiation surface (R). A light guide (30) having a surface (33), and a light source (40) disposed on one end surface (30L) of the light guide (30), the light source (40) being a light guide (30). The reflector (50) is attached to the other end surface (30R) of the light guide (30) via an adhesive (60) having a high light transmittance. By constructing a pseudo light source corresponding to the light source (40), the reflecting plate forming the pseudo light source is connected to the other end surface of the light guide through an adhesive material having high light transmittance. By sticking, like the light source disposed at a predetermined interval on one end surface of the light guide, a certain gap is generated between the reflector and the other end surface of the light guide by the adhesive material. As a result, the light environment between the light source and the pseudo light source becomes close, and a pseudo light source more similar to the light source can be created. Therefore, the illuminating device having this configuration is bright as in the case where the light sources are provided on both end faces of the light guide, and exhibits an excellent effect of obtaining the left and right spectral characteristics as linear light.

Furthermore, the reflecting plate (50) and the adhesive sheet (60) used for the pseudo light source are used as the reflecting plate that is cut in accordance with the outer shape of the other end face of the light guiding body (30), and the reflecting plate is used as the light guiding body. It is excellent in workability by being affixed to the other end surface of the light source, and it is reliably between the reflector (50) and the other end surface of the light guide (30) by simply affixing the reflector to the other end surface of the light guide. Since a certain gap can be provided, a gap can be formed between the reflector (50) and the light guide (39) by a simple method, and a light source is provided on each end face of the light guide. As in the case of the above, it is bright and has the effect of obtaining left and right uniform spectral characteristics as linear light.

In addition, it is good also as a structure which inclines the other end part (30R) pseudo | simulated by changing the thickness of an adhesive sheet, without inclining the edge part of the light guide (30) by the side of a pseudo light source.

<Isolation between reflector light sources>
Next, it supplements about isolation between the light sources by a reflector. As shown in FIGS. 11 and 12, the first light source (40) and the second light source (40) are separated from each other by the reflector (49), and the light irradiation region of the light guide (30) is separated. By separating the light entering the light guide (30) from the one end face (30a, 30b), the spectral characteristics of the light sources of the first and second light sources are individually regulated, and the optimum Light from the first and second light sources regulated by the spectral characteristics can be incident on the end face of the light guide only from the region regulated by the reflector, and illumination spots can be further suppressed.

<Frame body locking of light guide>
Next, it supplements regarding the frame locking of a light guide. As shown in FIGS. 7 and 9 (a) and 10, the light source (40) and the light from the light source (40) are guided along the illumination line direction, and the illumination areas (41a, 42a) are linear light. A light source (30) that illuminates the light source (40), and the light source (40) is disposed to face at least one end surface (30a, 30b) of the light guide (30), and the light guide (30) Includes an end face (30a, 30b) for capturing light, a diffuse reflection surface (32) for diffusing and reflecting light captured from the end face (30a, 30b), and an irradiation surface (for reflecting light diffusely reflected by the diffuse reflection surface (32)). R: a light exit surface (33) that emits toward the surface), and the light exit surface (33) is formed of a circumferential surface (radius r), and the diffuse reflection surface (32) is the circumference thereof. An optical axis normal line that exits from the light exit surface (33) through the center (P1) of the circle forming the surface (radius r) x) is an illuminating device disposed at a position where the light guide body (30) is formed, and includes a frame body (13) that houses the light guide body (30). The light guide body (30) has a diffuse reflection surface (32). A projection (30P) is formed on the side surface along the optical axis normal line (hx) to be formed and is locked to the frame (13) along the illumination line direction, and the light source (40 of the projection (30P)) ) Side end (32a) between the light source side end face (30a, 30b) of the diffuse reflection surface (32) and the light source side end face (30a, 30b) at the illumination line of the illumination area (41a, 42a). By forming in between, the reflected light reflected at the base end of the light entering the light guide from the light source is not disturbed by the protrusion, and the locking condition with the frame is maintained, In particular, there is little variation in the light amount distribution on the light source side end face in the illumination line of the illumination area. It is possible to suppress the more lighting spots.

[Industrial applicability]
The illumination apparatus according to the present invention can be used for apparatuses other than the above-described image reading apparatus. For example, the illumination apparatus can be used as an illumination apparatus for optical devices such as an optical microscope, a magnifying projector, and a projector, or a general household illumination apparatus. I can do it.

DESCRIPTION OF SYMBOLS 1 Apparatus housing 2 1st platen 3 2nd platen 5 Platen cover 6 Carriage 7 Condensing lens 8 Line sensor 9 Pulling fixing | fixed part 9 Light source 9a 1st light source 9b 2nd light source 10 Reflective mirror 10a 1st mirror 10b 2nd mirror (2nd mirror) 4 mirrors)
10c 3rd mirror 10d 5th mirror 10e 6th mirror 10f 7th mirror 11 Unit frame 12 Guide shaft 13 Light source housing part 13a 1st housing part 13b 2nd housing part 14 Heat radiation member 15 Heat-resistant sheet 16 Circuit board 16b Circuit part 16d Resin Numeral 17 Pulling member 18 Reflector 19 Traveling drive means 21 Lead roller 22 Unloading roller 23 Paper feed stacker 24 Paper feed roller 25 Registration roller pair 27 Backup roller 28 Paper discharge roller 29 Paper discharge stacker 30 Light guide 30N Hook 30P Projection 30S Light guide side surface 30L One end surface 30R The other end surface 31 Reading opening 32 Light scattering surface 33 Light emitting surface 40 Light emitter 40a Anode 40b Cathode 41 First light emitter (white LED)
42 Second light emitter (white LED)
43 Lens Cap 44 Power Supply 45 Sensor Circuit Board 46 Pulley 47 Insulating Mylar 48 Holding Member 49 Reflector A Image Reading Unit B Document Feeding Unit F1 Arrow F2 Arrow GL Rail Member HP Home Position Ld Distance Ld1 Distance Ld2 Distance MO Motor Mc Carriage Motor R Reading surface W Reading line width d Gap dx Offset amount ha arrow hb arrow hc Output optical path direction hx normal line P1 light guide center P2 second light emitter center P3 first light emitter center

Claims (8)

An illumination device that scatters and reflects light from a light source and irradiates a reading surface with linear light,
A light guide having a light scattering surface that scatters light from the light source in a line direction along the reading surface, and a light emitting surface that emits light from the light scattering surface toward the reading surface;
A light source disposed on one end surface of the light guide,
The light source is disposed at a predetermined interval on one end surface of the light guide,
An illuminating device, wherein a reflection plate is attached to the entire other end surface of the light guide through an adhesive having a predetermined thickness and high light transmittance. The adhesive material is composed of a sheet-like material having a light transmittance of 90% or more,
2. The illumination according to claim 1, wherein the reflection plate is made of a sheet material in which a sheet base material having a reflection surface formed on the front surface side and a release sheet having a separation surface on the back surface side is superimposed on the front and back surfaces of the adhesive material. apparatus. The other end surface of the light guide body forms an inclined surface,
The lighting device according to claim 1, wherein the reflector is attached to an inclined surface thereof. The light guide has a light exit surface formed by a circumferential surface,
Forming the reflective surface at a position separated by a predetermined distance outside the circumferential region;
The lighting device according to claim 1, wherein the light source includes one light emitter disposed between a center of a circle forming the circumferential surface and the circumferential surface. The light guide has a light exit surface formed by a circumferential surface,
Forming the reflective surface at a position separated by a predetermined distance outside the circumferential region;
The light source includes a first light emitter and a second light emitter,
The first light emitter is disposed between the circumferential surface of the circle forming the circumferential surface and the circumferential surface of the circumferential surface;
The lighting device according to claim 1, wherein the second light emitter is disposed in the circumferential region in accordance with a separation distance of the light scattering surface. Between the light guide and the light source, comprising a reflector that forms a reflective surface that regulates the light irradiation angle of the light source to the end surface of the light guide,
The light source is hermetically sealed with the reflector and the light guide,
The lighting device according to claim 1, wherein the light guide and the light source are held by the holding member via the reflector. A board on which the light source is mounted and a heat radiating member that receives and radiates heat generated by the light source through the board, and the holding member presses the light guide and the heat radiating member against the reflector, respectively. Item 7. The lighting device according to Item 6. A platen for placing a reading document, a light source unit including a light source for illuminating the reading document placed on the platen, and light receiving means for receiving reflected light from the reading document illuminated by the light source of the light source unit An image reading device comprising:
An image reading apparatus comprising the illumination device according to any one of claims 1 to 7.