CN207200825U - Light source module and imaging device - Google Patents

Abstract

The utility model provides a light source module and an image capturing device; the light source module comprises a substrate, a light guide rod and a plurality of light emitting diodes; the light guide rod is provided with a light incident surface and a light emergent surface, and the light emergent surface is adjacent to the light incident surface. The light emitting diodes are arranged on the substrate along a first axis and project light rays towards the light incident surface, and the distance between an optical axis of each light emitting diode and the first axis is not more than 0.5 mm. The image capturing device comprises the light source module, a base, an imaging module and a sensing module, wherein the light source module is arranged in the base and emits light rays towards an object; the imaging module is arranged in the base and is used for imaging the light reflected by the object on the sensing module positioned on the other side of the base.

Description

Light source module and imaging device

technical field

The utility model relates to a method or device for reading or recognizing printed or written characters or for recognizing graphics, and particularly relates to a light source module and an image capturing device of a linear image sensor.

Background technique

Contact image sensor (contact image sensor) is a kind of linear image sensor, mainly used in scanners, fax machines and multi-function business machines, to scan flat images or documents into electronic format, so that store, display or transmit.

The working principle of the contact image sensor is to irradiate the light generated by the light source on the manuscript to be scanned, reflect the light through the manuscript, and use a lens group to gather the reflected light on the photosensitive element; The signal is changed into an electrical signal to generate analog or digital pixel (pixel) data.

Currently, the light sources generally used in contact image sensing devices on the market mainly provide a white light to irradiate objects; however, LEDs that use blue light-emitting chips and yellow phosphors to produce white light will cause poor image quality due to poor color rendering. bad.

Utility model content

According to the utility model, a light source module is provided, which is used in an image-taking device; the light source module includes a substrate, a light guiding rod and a plurality of light emitting diodes. The light guide rod has a light incident surface and a light exit surface, and the light exit surface is adjacent to the light incident surface. The light-emitting diodes are arranged on the substrate and arranged along a first axis and project light toward the light-incident surface. The distance between an optical axis of each light-emitting diode and the first axis is not greater than 0.5 millimeters. Secondly, the first axis is parallel to the normal of the light-emitting surface.

In one embodiment of the present invention, the light emitting diodes in the light source module cooperate to generate a white light, and among the light emitting diodes of the light source module, the light emitting diodes closest to the light-emitting surface are arranged to generate light with a wavelength between 606 and 626 nanometers. The light emitting diodes arranged next to the light-emitting surface are for generating light with a wavelength of 508-555 nanometers, and the light-emitting diodes arranged farthest from the light-emitting surface are for generating light with a wavelength of 450-480 nanometers.

In one embodiment of the present utility model, a plurality of microprisms of the light guiding rod are formed on a bottom surface of the light guiding rod, and the bottom surface is opposite to the light emitting surface; the arrangement density of the microprisms is inversely proportional to the light intensity received by the arrangement position.

In one embodiment of the present invention, the light source module further includes a reflector installed on the substrate, a side wall of the reflector surrounds the plurality of light emitting diodes, and the inner diameter of the side wall increases as the distance away from the substrate .

In an embodiment of the present invention, the reflector further includes a bottom wall connected to a side of the side wall adjacent to the substrate, and the light-emitting diodes are arranged on the bottom wall.

In one embodiment of the present invention, the light source module further includes a joint, the light-emitting diode and the reflector are arranged on one side of the joint, and the light guiding rod is installed on the other side of the joint to receive the white light emitted by the light-emitting diode. light.

In an embodiment of the present invention, the light source module further includes a protective part, which partially covers the light guiding rod, and the light incident surface and the light outgoing surface are exposed outside the protective part.

According to the present invention, an image capturing device is further provided for capturing an image of an object; the image capturing device includes the aforementioned light source module, a base, a sensing module and an imaging module. The base includes an accommodating groove and a through groove, the light source module is arranged in the accommodating groove, and the object is located on one side of the base. The sensing module is located on the other side of the base, and includes a plurality of photosensitive elements arranged along a second axis. The imaging module is installed in the slot, and is used to image the image of the object on the photosensitive element.

In one embodiment of the present invention, the included angle between the first axis and an optical axis of the photosensitive member is between 35° and 65°.

The imaging device of the utility model provides a white light source with high color rendering property to irradiate the object by properly arranging the light-emitting diodes for generating blue light, green light and red light in the light source module and their relative positions with the light-emitting surface, so as to achieve Effects that improve image quality.

Description of drawings

Fig. 1 is a three-dimensional exploded view of an imaging device according to the present invention;

Fig. 2 is a partial exploded view of the imaging device according to the present invention;

Fig. 3 is a top view of a substrate, a reflector and a light emitting diode according to the present invention;

Fig. 4 is a three-dimensional combined view of the light source module according to the present invention; and

Fig. 5 is a cross-sectional view of the imaging device according to the present invention.

Instructions for marks in the figure:

1 image taking device; 10 seat body; 100 top surface; 102 bottom surface; 104 accommodating groove; 106 through groove;

12 light source module; 120 substrate; 1200 through hole; 1202 conductive part; 122 light guiding rod; 1220 light incident surface;

1222 light-emitting surface; 1226 microprism; 124 reflector; 1240 side wall; 1242 bottom wall;

126B, 126G, 126R light-emitting diodes; 128 protective parts; 130 joint parts; 132 convex ribs;

14 imaging module; 16 sensing module; 160 circuit board; 162 photosensitive element; 164 connection pad;

A first axis; C optical axis.

Detailed ways

FIG. 1 is a three-dimensional exploded view of an image-taking device according to the present invention, and FIG. 2 is a partial exploded view of the image-taking device according to the present invention. In FIG. 1 and FIG. 2 , an imaging device 1 is used to sense an image of a (flat) object, and convert the optical image of the object into an analog or digital electronic signal for storage and transmission. The imaging device 1 includes a base 10 , a light source module 12 , an imaging module 14 and a sensing module 16 .

The seat body 10 includes a top surface 100 , a bottom surface 102 opposite to the top surface 100 , an accommodating groove 104 and a through groove 106 ; the bottom surface 102 is substantially parallel to the top surface 100 . The accommodating groove 104 is formed on the top surface 100 and is recessed toward the bottom surface 102 , and the through groove 106 is a slot structure penetrating through the top surface 100 and the bottom surface 102 . The seat body 10 can be made of plastic or other polymer materials by injection molding or casting techniques. The base body 10 can be made of black or other dark materials without reflective effect, so as to prevent the optical image generated by the reflection of the object from being reflected by the base body 10 and affecting the imaging contrast. In other words, it is not recommended to use white or silver or other materials with reflective effect to make the seat body 10 .

The light source module 12 is used to generate a linear light to illuminate objects. The light source module 12 includes a substrate 120 , a light guiding rod 122 , a light reflector 124 and a plurality of LEDs 126B, 126G, 126R. The substrate 120 can be a printed circuit board or a flexible print circuit; wherein, the flexible print circuit can effectively reduce the volume and weight of the light source module 12 .

The light guiding rod 122 can transmit light, and includes a light incident surface 1220 and a light exit surface 1222; the light incident surface 1220 is used to receive the light generated by the light emitting diodes 126B, 126G, 126R, and the light exit surface 1222 is adjacent to the light incident surface 1220, and is used for For light to exit.

The bottom surface (not otherwise labeled) of the light guide rod 122 can form a plurality of microprisms 1226, which are used to make the light entering the light guide rod 122 from the light incident surface 1220 be transmitted to the far light side (ie away from the light incident surface 1220); The bottom surface is adjacent to the light incident surface 1220 and may be opposite to the light exit surface 1222 . The number of microprisms 1226 varies with the intensity of light received at the location where they are arranged, and can be non-linear, for example; thereby, the uniform brightness of the linear light output from the light emitting surface 1222 can be achieved.

More specifically, in the vicinity of the light incident surface 1220, the number of microprisms 1226 arranged per unit area is low (i.e. low density); The number is high (that is, high density); in other words, the arrangement density of the microprisms 1226 is inversely proportional to the light intensity received by the arrangement positions.

The reflective element 124 is disposed on the substrate 120 and includes a side wall 1240 and a bottom wall 1242 ; the reflective element 124 can be made of a color with high reflective effect such as white or silver. The inner diameter of the side wall 1240 increases as the distance from the substrate 120 increases, so as to change the transmission path of the large-angle light generated by the light-emitting diodes 126B, 126G, and 126R, so that the large-angle light can be smoothly coupled to the light guiding rod 122, thereby improving light utilization. Effect. The bottom wall 1242 is connected to one side of the side wall 1240 adjacent to the substrate 120 for supporting the LEDs 126B, 126G, 126R.

The reflector 124 also includes a plurality of connectors 1244, one end of which can be arranged on the bottom wall 1242 for electrical connection with the light emitting diodes 126B, 126G, 126R; form an electrical connection.

Please refer to FIG. 3 ; the LEDs 126B, 126G, 126R are arranged on the bottom wall 1242 along a first axis A, and the sidewall 1240 surrounds the LEDs 126B, 126G, 126R. The distance between the optical axis I of each light emitting diode 126B, 126G, 126R and the first axis A is not more than 0.5 mm; wherein, the optical axis C is the light emitted by each light emitting diode 126B, 126G, 126R in space. The axis of symmetry of the intensity distribution.

The light emitting diodes 126B, 126G, and 126R can emit light at different time points respectively; For green light, the light emitting diode 126R is used to generate red light with a wavelength between 606-626 nanometers.

Please refer to FIG. 4; when the light-emitting diodes 126B, 126G, 126R are assembled with the light-guiding rod 122, the first axis A is parallel to a normal line to the light-emitting surface 1222; The second arrangement is closest to the light emitting surface 1222 , and the light emitting diode 126B is arranged farthest from the light emitting surface 1222 ; in other words, the light emitting diode 126G is arranged between the light emitting diodes 126R and 126B. Accordingly, imaging quality can be improved. In actual implementation, the relative positions of the light-emitting diodes 126B, 126G, 126R and the light-emitting surface 1222 can be adjusted according to actual needs.

It should be noted here that the light emitting diodes 126B, 126G, 126R can also be directly mounted on the substrate 120 . In the aforementioned state, the reflector 124 only includes the side wall 1240 for surrounding the light emitting diodes 126B, 126G, 126R to change the transmission path of the large-angle light emitted by them. In other words, when the light emitting diodes 126B, 126G, 126R are directly installed on the substrate 120 , the light reflector 124 may not include the aforementioned bottom wall 1242 ; thus, the overall length of the light source module 12 can be reduced.

The light source module 12 may further include a protection part 128 and a joint part 130 . The protective member 128 partially covers the light guiding rod 122 and at least exposes the light incident surface 1220 and the light emitting surface 1222 ; the protective member 128 is mainly used to protect the light guiding rod 122 and prevent the light guiding rod 122 from being broken due to no support during assembly or transportation. The protective member 128 can be made of white or silver material with reflective effect, so that it can reflect part of the light that is not emitted from the light-emitting surface 1222 of the light-guiding rod 122 , so as to improve the efficiency of light use.

One end of the joint 130 is provided with a reflector 124 and LEDs 126B, 126G, 126R, and the light guide rod 122 is arranged at the other end of the joint 130 to receive blue light, green light, red rays. In other words, an opening (not shown) with a suitable aperture is provided at the center of the joint member 130 so that the blue light, green light, and red light generated by the LEDs 126B, 126G, and 126R can be smoothly coupled to the light guiding rod 122 . In other words, the joint member 130 can provide the positioning of the light guiding rod 122 and the light emitting diodes 126B, 126G, 126R and the effect of improving the light coupling rate. A plurality of convex ribs 132 are formed on one side surface of the bonding member 130 for accommodating the LEDs 126B, 126G, 126R, and the ribs 132 pass through the through holes 1200 formed on the substrate 120 to achieve a positioning effect. Furthermore, by controlling the timing of the blue light, green light, and red light generated by the light emitting diodes 126B, 126G, and 126R, the light emitted from the light emitting surface 1222 can be mixed and visible to the human eye.

Referring again to FIG. 1 , the imaging module 14 is accommodated in the slot 106 for imaging the image of the object on the sensing module 16 ; the imaging module 14 may include a plurality of progressive refractive index lenses, for example.

The sensing module 16 is disposed on one side of the base body 10 and includes a circuit board 160 and a plurality of photosensitive elements 162 . The circuit board 160 can be, for example (but not limited to), a printed circuit board; the plurality of conductive parts 1202 on the substrate 120 can be electrically connected to the plurality of connection pads 164 on the circuit board 160 to capture the light emitting diodes 126B, 126G, and 126R. electricity required.

The photosensitive element 162 is arranged on the circuit board 160 along a second axis and is electrically connected to the circuit board 160; the angle θ between an optical axis of the photosensitive element 160 and the first axis A can be between 35° and 65° (as shown in FIG. 5 ), and the photosensitive element 162 is arranged corresponding to the through groove 106 to receive the optical image generated by the object reflecting the light generated by the light source module 12 , and further convert the optical image into an analog or digital electronic signal. The photosensitive element 162 can be a charge-coupled device, a complementary metal-oxide-semiconductor device or other devices with photoelectric conversion properties.

The light-emitting diodes 126B, 126G, and 126R of the imaging device 1 of the present utility model can increase the uniformity of the outgoing light through proper positioning; moreover, by properly arranging the LEDs in the light source module 12 for generating blue light, green light and red light The relative positions of the light emitting diodes 126B, 126G, 126R and the like to the light emitting surface 1222 are used to improve the imaging quality.

The above-mentioned embodiments are only preferred embodiments for fully illustrating the utility model, and the protection scope of the utility model is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present utility model are all within the protection scope of the present utility model. The scope of protection of the utility model shall be determined by the claims.

Claims (9)

1. a kind of light source module group, it is characterised in that the light source module group includes：

One substrate；

One light guide bar, has an incidence surface and an exiting surface, and the exiting surface is adjacent to the incidence surface；And

Multiple light emitting diodes, on the substrate, the multiple light emitting diode is arranged along a first axle and direction The incidence surface throw light, and the distance between an optical axis of each light emitting diode and described first axle are not more than 0.5 millimeter,

Normal of the wherein described first axle parallel to the exiting surface.

2. light source module group as claimed in claim 1, it is characterised in that in the multiple light emitting diode, arrangement is closest The light emitting diode of the exiting surface is arranged and gone out described in secondary be adjacent to for producing wavelength between 606 ~ 626 nanometers of light The light emitting diode of smooth surface arranges the institute farthest away from the exiting surface for producing wavelength between 508 ~ 555 nanometers of light Light emitting diode is stated for producing wavelength between 450 ~ 480 nanometers of light.

3. light source module group as claimed in claim 1, it is characterised in that the light guide bar includes multiple microprisms, the multiple Microprism is formed on a bottom surface of the light guide bar, and the bottom surface is relative to the exiting surface, the cloth of the multiple microprism If density is in inverse ratio with the light intensity received by its installation position.

4. light source module group as claimed in claim 1, it is characterised in that also comprising a reflecting element, be installed on the substrate, institute State a side wall of reflecting element increases around the multiple light emitting diode, the internal diameter of the side wall with away from the substrate.

5. light source module group as claimed in claim 4, it is characterised in that the reflecting element also includes a bottom wall, is connected to described Side wall is adjacent to the side of the substrate, and the multiple light emitting diode is on the bottom wall.

6. light source module group as claimed in claim 4, it is characterised in that also comprising a fastener, the multiple light emitting diode And the reflecting element is located at the side of the fastener, the opposite side that the light guide bar is installed on the fastener is described to receive Light caused by multiple light emitting diodes cooperations.

7. light source module group as claimed in claim 1, it is characterised in that also comprising a guard member, the light guide bar is partly coated, The incidence surface and the exiting surface expose outside the guard member.

A kind of 8. image-taking device, to capture the image of an object, it is characterised in that the image-taking device includes：

Light source module group as any one of claim 1 to 7；

One pedestal, comprising a storage tank and a wears groove, the light source module group is located in the storage tank, and the object is positioned at described The side of pedestal；

One sensing module, positioned at the opposite side of the pedestal, the sensing module is included along the multiple of second axis arrangement Sensitive piece；

One imaging modules, be installed in the wears groove, and to by the video imaging of the object in the multiple sensitive piece.

9. image-taking device as claimed in claim 8, it is characterised in that the optical axis of the first axle and the multiple sensitive piece Angle between 35 ~ 65 degree.