JPH09330611A - Image reading device and light source unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unify the irradiated state of an object by classifying usable light sources into multiple groups according to their luminous characteristics, and arranging the light sources belonging to the same group within multiple groups at different positions of a light guiding means. SOLUTION: The rank in each luminous wavelength range is determined according to the measured luminous spectrum. In the first luminous wavelength area, the central wavelength of 600-605nm is set to the rank A, 605-610nm is set to the rank B, 610-615nm is set to the rank C, and 615-620nm is set to the rank D, for example. The second and third luminous wavelength ranges are likewise ranked. LED lamps 1, 2 belonging to the same group of the luminous spectrum are extracted, and they are arranged at both ends of a light guide body 3. When the LED lamps are classified according to the rank, the LED lamps of the same rank can be integrated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus used for, for example, a facsimile, a scanner, etc., and an illuminating apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, an LED chip as shown in FIG. 40 has been used as a document illumination light source for an image reading apparatus such as a facsimile machine or an electronic copying machine which electrically captures and processes image information of a document, a book or the like. The one using is widely used.

A plurality of LEs arranged on the LED substrate 50
The light emitted from the D chip 60 illuminates the original 10. Then, the reflected light from the document is imaged by the unity-magnification optical system 11 on the sensor 12 arranged on the sensor substrate 14 and converted into an image signal.

Such an illuminating device is intended for monochrome reading of image information, and in the case of red, only a plurality of LED chips in the red emission wavelength range and in the case of green, a plurality of LED chips in the green emission wavelength range are provided on the same substrate. The so-called LED array mounted in the above has been used. This type of light source is L
ED chip image reading width (216m for A4 size
m, B4 is 256 mm), with a sufficiently fine pitch (usually 10 mm) so that uneven illumination does not occur.
Hereinafter, it has a structure in which a plurality (usually 20 or more) are arranged.

Further, in recent years, with the widespread use of personal computers, there has been an increase in the usage of once capturing image information in a computer with an image scanner and displaying it on a color display for processing. Furthermore, inexpensive devices, such as inkjet printers, that can easily output color images have become widespread. As a result, it is becoming an indispensable condition to capture image information as a color image.

Conventionally, a discharge tube such as a fluorescent tube has been mainly used as an illuminating device in a color image reading device which takes in these image information as a color image. this is,
A white light source, red, or
Blue and green light sources are required. The simplest way to obtain a white light source or a three-color light source is to use a discharge tube such as a fluorescent tube. However, in terms of size, cost, power consumption, and the like, the LED that is often used for monochrome reading is more advantageous.

Red LEDs and green LEDs have been put to practical use with relatively high brightness from the past, but blue LEDs are only much darker, which makes it practical to perform color reading using LEDs as light sources. It was hindering me. However, with respect to the blue LED, one having a dramatically high brightness has been developed in recent years.

In order to obtain linear illumination required for an image reading apparatus using LEDs, a large number of LED chips are arranged to form an LED array, and a small number of LEDs are used by using a special optical member as shown in FIG. There has been proposed a method of expanding a light beam emitted from a linear beam. Such a light source is shown in detail in FIG. In FIG. 42, the light emitted from the LED lamp 1 made by bonding an LED chip onto a metal lead and sealing that portion with a transparent resin in a lens shape has a circular cross section, for example, acrylic resin. A light beam propagating through the light guide body 3 made of a light-transmissive member such as is reflected and scattered by the reflection region 5 and is extracted to the outside of the light guide body 3. Here, the reflection area 5 is formed by forming the surface of the light guide 3 into a minute sawtooth shape.

A reflecting surface 6 is provided at the end portion of the light guide 3 opposite to the incident surface side. The reflecting surface 6 is formed by vapor-depositing a metal such as aluminum on the surface of the end portion of the light guide 3 itself or applying a light diffusive and reflective paint, but when it is provided as a separate member. There is also.

With such a structure, the light flux L emitted from the LED lamp 1 and entering the light guide 3 through the incident surface 4 of the light guide 3 is repeatedly reflected on the inner surface of the light guide 3 and the inside thereof. To reach the surface on the opposite side of the incident surface 4, where it is also reflected and propagates inside the light guide 3. Then, when light is incident on the reflection area 5 while repeating reflection,
The light flux is reflected there, and the light is emitted to the outside with the side facing the area 5 as the emission surface.

FIG. 43 is an application of the configuration shown in FIG. 42 to a collar. In FIG. 43, the LED chip 1
Is obtained by bonding a plurality of LED chips having emission wavelength regions different from each other onto a lead made of metal and sealing the portion with a transparent resin in a lens shape. This LED
An enlarged view of the lamp 1 is shown in FIGS. 44 (a) and 44 (b). FIG.
As shown in FIG. 4 (a), the LED lamp 1 contains red (R), green (G), and blue (B) LED chips 1a, 1b, and 1c having different emission wavelength ranges. Where red LE
The D chip is an LED chip whose main emission wavelength is 590 nm or more, the green LED chip is an LED chip whose main emission wavelength is 490 nm or more and 590 nm or less, and the blue LED chip is an LED chip whose main emission wavelength range is 490 nm or less. There is.

Using such a method, a small number of LEDs
A lamp can be used to uniformly illuminate a sufficiently long effective length. Even if an expensive high-brightness blue LED is used, it is possible to configure an inexpensive color image reading light source as compared with an LED using a large number of LEDs.

However, in the method in which the light source is provided only on one end face of the light guide member, the end face side having the light source is bright and the other end face side having the reflecting face is darker than that as shown in FIG. Prone. Therefore, uneven illumination tends to increase. Further, since the light source is provided only on one end face, there is a drawback that the total amount of light cannot be increased. To eliminate such drawbacks,
As shown in FIG. 46, there is a method of providing LED lamps at both ends of the light guide, and a larger amount of light can be obtained as the number of LED lamps increases. Further, as shown in FIG. 47, it is possible to reduce uneven illumination.

[0014]

However, when the light sources are provided at both ends of the light guide as described above, there arises a problem that has not occurred in the method of providing the light sources on one side of the light guide.
In the method in which the light source is provided on only one side of the light guide, the spectrum, which is the emission characteristic of the illumination light, is substantially constant regardless of the position on the illuminated surface. This is because the light beams emitted from the light sources provided on one side of the light guide are mixed with each other in the vicinity of the incident surface of the light guide, and even if there are a plurality of light sources that emit light at the same time, the emission spectra are slightly different. Even if they are different
This is because almost the entire surface to be illuminated is illuminated with the mixed spectral distribution.

However, when the light sources are provided at both ends of the light guide, the influence of the light source closer to each end face is stronger as shown in FIG. 48 when the light source spectra at both ends are different. To receive it, it may be illuminated by light with a different spectral distribution depending on the location. Then, even if the same color original is read, there is a problem that different colors are read depending on the place.

[0016]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in an image reading apparatus according to claim 1, a plurality of light sources and a plurality of light sources at different positions are provided. Image reading having a light guide unit that is disposed in the light guide unit to illuminate a subject by guiding light emitted from a light source, and a photoelectric conversion unit that converts the light from the subject illuminated by the light guide unit into an image signal In the device, the light emission wavelength region of the light source is divided into a plurality of regions, and a plurality of light sources belonging to the same region among the divided regions can be used for reading and light sources that cannot be used according to variations in emission characteristics. And further classify the light source to be used into a plurality of groups according to its light emitting characteristics, and arrange the light sources belonging to the same group among the plurality of groups at different positions of the light guide means. Wherein the homogenized the irradiation state of the object using.

According to another aspect of the image reading apparatus of the present invention, a plurality of LEDs and a light guiding means for illuminating a subject by arranging the plurality of LEDs at different positions and guiding light emitted from the LEDs. In an image reading apparatus having a photoelectric conversion unit that converts light from a subject illuminated by the light guiding unit into an image signal, a plurality of LEDs are cut out from the same wafer having variations in light emission characteristics, and the cut LEDs are cut out. The LEDs that can be used for reading and the LEDs that cannot be used are classified according to the variation in the light emission characteristics of the LEDs, and the LEDs that can be used for reading are further classified into a plurality of groups, and the LEDs are classified into the same group among the plurality of groups. It is characterized in that the illumination state of the subject is made uniform by disposing the belonging LEDs at different positions of the light guide means.

In the image reading apparatus according to the twentieth aspect of the invention, a plurality of light sources, and a light guide means for illuminating an object by arranging the plurality of light sources at different positions and guiding the light emitted from the light sources. In an image reading apparatus having a photoelectric conversion unit that converts light from the subject illuminated by the light guide unit into an image signal, the emission wavelength range of the light source is divided into a plurality of regions, and the same region among the separated regions is used. A plurality of light sources belonging to a region are classified into a first group at the center of variation and second and third groups on both sides thereof according to variations in light emission characteristics, and belong to the same group of the first, second or third groups. By arranging light sources at different positions of the light guide means, the irradiation state of the subject is made uniform.

According to a thirtieth aspect of the present invention, in the image reading apparatus, a plurality of LEDs and light guiding means for illuminating an object by arranging the plurality of LEDs at different positions and guiding the light emitted from the LEDs. In an image reading apparatus having a photoelectric conversion unit that converts light from a subject illuminated by the light guiding unit into an image signal, a plurality of LEDs are cut out from the same wafer with variations in light emission characteristics, and the cut LEDs are used. LEDs belonging to the same group of the first, second or third groups are classified into a first group at the center of the variation and a second group and a third group on both sides of the variation according to the light emission characteristics. It is characterized in that the irradiation state of the subject is made uniform by arranging the same in places.

According to a thirty-ninth aspect of the invention, in a light source unit that can be used in an image reading apparatus, a plurality of light sources and a plurality of the light sources are arranged at different positions, and the light emitted from the light sources is guided to guide an object. A light emitting means for irradiating the light source, the light emission wavelength region of the light source is divided into a plurality of regions, and a plurality of light sources belonging to the same region among the separated regions can be used for reading according to variations in light emission characteristics. The light sources are classified into light sources and unusable light sources, the light sources to be used are further classified into a plurality of groups according to their emission characteristics, and the light sources belonging to the same group among the plurality of groups are different in the light guide means. It is characterized in that the irradiation state of the subject is made uniform by arranging the same in places.

According to a 49th aspect of the present invention, there is provided a light source unit usable in an image reading apparatus, wherein a plurality of LEDs and a plurality of L's are provided.
EDs are arranged at different positions, and the light guide means for irradiating the subject by guiding the light emitted from the LEDs is provided.
Multiple LEDs are cut out from the same wafer with variations in light emission characteristics, and are classified into LEDs that can be used for reading and LEDs that cannot be used according to variations in the light emission characteristics of the cut LEDs, and can be used for the above reading. Na L
It is characterized in that the EDs are classified into a plurality of groups, and the LEDs belonging to the same group among the plurality of groups are arranged at different positions of the light guide means to make the irradiation state of the subject uniform.

In the light source unit that can be used in the image reading apparatus according to the present invention, a plurality of light sources and a plurality of the light sources are arranged at different positions and the light emitted from the light sources is guided to illuminate a subject. A light guide means for dividing the light emission wavelength range of the light source into a plurality of regions, and a plurality of light sources belonging to the same region among the separated regions are dispersed in accordance with variations in light emission characteristics. Group and second on both sides
And a third group, the first, second or third
By arranging light sources belonging to the same group of the groups at different positions of the light guide means, the irradiation state of the subject is made uniform.

According to a sixty-eighth aspect of the present invention, in a light source unit usable in the image reading apparatus, a plurality of LEDs and a plurality of L's are provided.
A plurality of LEs are provided from the same wafer that has EDs arranged at different locations and guides the light emitted from the LED to illuminate the subject.
D is cut out, and the cut out LEDs are varied according to the light emission characteristics. The first group in the central part and the second and third groups on both sides thereof.
The LEDs are classified into groups, and the LEDs belonging to the same group of the first, second, or third groups are arranged at different positions of the light guide unit to uniformize the irradiation state of the subject.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

<< First Embodiment >> FIG. 1 shows a first embodiment of the present invention.
FIG. 3 is a configuration diagram of the image reading device in the embodiment. In FIG. 1, LED lamps 1, which constitute a light source unit,
The light 9 emitted from 2 and guided and reflected by the light guide 3 illuminates the original 10 in a line. The reflected light from the original 10 is imaged by the equal-magnification optical system 11 on the line sensor 12 formed on the substrate 13 and converted into an image signal.

Next, FIG. 2 is a diagram showing a configuration of a light source unit used in the image reading apparatus shown in FIG. FIG.
In the above, a plurality of Ls having different emission wavelength ranges from each other
LED lamps 1 and 2 are provided at both ends of the light guide 3 by bonding an ED chip onto a metal lead, and sealing that portion with a transparent resin in a lens shape to form one unit. ing.

The light guide 3 has a circular cross section and is made of a light-transmissive member such as acrylic resin, and an incident surface 41 on which the light beam emitted from the LED lamp 1 or 2 enters the light guide 3. , 42, and a reflection region 5 for reflecting / scattering the light beam propagating through the light guide 3 and taking it out of the light guide 3. In the present embodiment, the reflection area 5 is formed by forming the surface of the light-transmissive member 3 into a minute sawtooth shape and further vapor-depositing aluminum on the surface. Here, the reflective region may be formed by coating or printing a light-reflective coating instead of aluminum vapor deposition. Alternatively, total reflection or Fresnel reflection on the inner surface of the sawtooth portion may be used without forming such a film.

The light beams emitted from the LED lamps 1 and 2 and made incident on the light guide body 3 through the incident surfaces 41 and 42 of the light guide body 3 are repeatedly reflected on the inner surface of the light guide body 3 and propagate therein. To do. When the light beam is incident on the reflection area 5 while repeating the reflection, the light flux is reflected there, and the light is emitted to the outside with the side facing the area 5 as the emission surface.

Next, an enlarged view of the LED lamp 1 is shown in FIG. LEs of red R, green G, and blue B with different emission wavelength ranges
D chips 1a, 1b, 1c and 2a, 2b, 2c are provided. In the present embodiment, LEDs that are light sources in the respective emission wavelength ranges are provided at different ends of the light guide body 3.
The chips 1a, 1b, 1c and 2a, 2b, 2c are light sources of the same emission wavelength range, that is, the red LED chip 1
a and 2a, green LED chips 1b and 2b, and blue LED chips 1c and 2c are configured so as to have light emission characteristics that are close to each other. This will be described later in detail. Further, the light sources in the same emission wavelength range are turned on at the same time, and the light sources in different emission wavelength ranges are turned on separately.

Next, light sources of the same luminous efficiency range arranged at different ends of the light guide 3, that is, the red LEDs 1a and 2a, the green LEDs 1b and 2b, and the blue LEDs 1c and 2c, have emission spectra close to each other. A method of configuring to have will be described.

The steps for producing the LED lamp 1 as shown in FIG. 2 are shown in FIGS. First, the LED as shown in Figure 4.
A metal frame 101 serving as a support for mounting the chip is prepared, and the LED chip 101a in the first emission wavelength range (for example, R) is mounted on the frame as shown in FIG.
Similarly, the LED chip 101b in the second emission wavelength range (for example, G) is mounted as shown in FIG. 6, and the LED chip 101c in the third emission wavelength range (for example, B) is further mounted as shown in FIG. Then, as shown in FIG. 8, wire bonding is applied to these LED chips, a lens-shaped resin is formed on the chips as shown in FIG. 9, and each LED lamp is separated as shown in FIG.

Next, in order to construct the light sources of the same emission wavelength range arranged at different ends of the light guide body 3 so as to have emission spectra close to each other, the LED lamp 1 thus completed For each one, only the LED chip in the first emission wavelength range is caused to emit light and the emission spectrum thereof is measured.

FIG. 11 is a diagram showing how the emission spectrum of the LED lamp is measured. First, a voltage is applied to a terminal connected to the LED chip in the first emission wavelength range of the LED lamp 1, and the luminous flux emitted by the LED at this time is analyzed by the spectroscopic device 20.
The emission spectrum distribution is examined by the sensor after the light is dispersed by 0. The measured emission spectrum data is output as it is, or is appropriately sent to the data processing device in the next stage, and the processing for ranking described later is performed.

According to the emission spectrum thus measured, the rank in the emission wavelength is determined.
Here, various indexes can be considered as an index for ranking by the emission spectrum, but the simplest method is to use the peak wavelength of the emission spectrum as an index as it is. In addition to these, the center of gravity wavelength obtained by weighting the intensity of each wavelength and taking the average, the dominant wavelength taking into consideration the relative luminous efficiency, or the spectral intensity ratio at appropriately determined multiple wavelengths, the spectral half of the emission peak Price range etc.

The method of ranking by the emission peak wavelength is as follows:
It is excellent in that it can be easily ranked without any special data processing after the emission spectrum measurement. Further, the method of ranking by the center of gravity wavelength or the dominant wavelength is excellent in that the ranking can be performed without being confused by noise accompanying measurement, local deformation of the emission spectrum shape, or the like. Further, the method of ranking by the spectral intensity ratio at a plurality of wavelengths and the spectral half width of the emission peak is not limited to the position of the emission spectrum,
It is excellent in that it can be ranked in consideration of the spread and shape of the emission spectrum. Depending on the required image reading accuracy, the variation of the emission spectrum of the LED, the measurement accuracy of the emission spectrum, etc., these indexes are appropriately determined,
They may be used in combination as needed.

In the present embodiment, a method of using the center-of-gravity wavelength that is not easily affected by noise associated with measurement and local deformation of the emission spectrum shape and is suitable for measurement in an actual process is adopted. Then, the rank in the emission wavelength range is determined according to the measured emission spectrum.

For example, in the first emission wavelength range, the center of gravity wavelength is 600 nm or more and less than 605 nm in A rank, the center of gravity wavelength is 605 nm or more and less than 610 nm in B rank, and the center of gravity wavelength is 610 nm or more and less than 615 nm in C rank. D rank from 615 nm to less than 620 nm ...
So decide. When the center-of-gravity wavelength of the first emission wavelength range of this LED lamp is 607 nm, the rank is B.

Similarly, the second and third emission wavelength ranges are similarly ranked. And by ranking in this way, for one LED lamp,
The rank of each emission wavelength range is determined as B rank for the first emission wavelength range, A rank for the second emission wavelength range, and C rank for the first emission wavelength range.

It should be noted that how finely the emission wavelength range is divided may be changed depending on the emission wavelength range. In general, the human eye is sensitive to green light to slight variations in its color tone, but less sensitive to red and blue light than green. Therefore, in the present embodiment, when the LEDs in the green wavelength range are classified into ranks, it is 3
Ranks are set every nm, and ranks are set every 5 nm for other wavelength ranges. By setting the ranks in this way, it is possible to perform high-quality image reading without dividing the ranks more than necessary. Of course, the ranking method is not limited to this.

Next, the rank as one LED lamp is defined by the combination of the emission spectrum ranks of the light sources mounted in the LED lamps in the respective emission wavelength ranges. For example, LED lamps of rank A for all emission wavelength ranges are AAA ranks, while those of rank A for the first emission wavelength range are second rank,
Regarding the third emission wavelength range, the LED lamp of B rank is defined as ABB rank.

Then, as shown in FIG. 12, the LED lamps of the same rank can be put together by classifying them according to the ranks of the LED lamps thus completed. When a color light source unit is constructed by combining the LED lamps thus classified with a light guide,
LED lamps belonging to the same or close ranks are used for one color light source unit. Then, it becomes possible to configure the light sources of the same emission wavelength range arranged at different ends of the light guide body so as to have emission spectra close to each other.

FIG. 13 shows the spectrum of the illumination light on the surface to be illuminated, which is illuminated by the LED lamp constructed as described above. As shown in FIG. 13, since the emission spectra of the LEDs in each emission wavelength range in the present embodiment are close to each other, the spectrum of the illumination light is substantially constant regardless of the position of the irradiation surface. Therefore, it is possible to solve the problem that originals of the same color are read as different colors depending on places. Furthermore, when there are variations in the light emission characteristics of the LEDs, most of them have standard light emission characteristics, and the distribution of the variations becomes a mountain shape as shown in FIG.
Conventionally, LE in the central part of this mountain, for example, CD rank
Although D was extracted and attached to the device, in the present embodiment, not only the central portion but also the AB rank or EF rank LEDs on both sides thereof can be used.
The LED cut out from the wafer can be utilized without waste, and high-quality reading can be performed.

In the present embodiment, the emission spectrum is described as an example of the emission characteristic of the LED lamp, but the present invention is not limited to this, and the LED lamp may be ranked according to the emission efficiency or the emission amount of the LED lamp. Further, the optical system is not limited to the equal-magnification optical system as in the present embodiment, but may be a reduction optical system as shown in FIG.

<Second Embodiment> Another method for constructing light sources of the same emission wavelength range arranged at different ends of a light guide member so as to have emission spectra close to each other will be described below. A second embodiment will be described.

In FIG. 16, the metal frame is prepared in the same manner as in the first embodiment, but L is attached to both ends of the same color LED light source in advance in the future.
Make sure you understand the part that will be the ED lamp. FIG.
The part A of the frame is attached to both ends of the same color LED light source. In addition, the LED lamp that can be separated from this series of frames is always combined with the LED lamp that is made from the same frame, and the same L
It may be attached to both ends of the ED light source.

Next, consider the case of mounting an LED chip in the first emission wavelength range. Here, LED chips having the same emission spectrum are mounted on the portions which become the LED lamps attached to both ends of the same color LED light source. Specifically, as shown in FIG. 17, the emission spectrum of each LED chip on the wafer is measured in advance, and the center of gravity wavelength is 600 nm or more and 605 nm.
Is less than A rank, the centroid wavelength of 605 nm or more and less than 610 nm is B rank, the centroid wavelength of 610 nm or more and less than 615 nm is C rank, and the centroid wavelength of 615 nm or more and less than 620 nm is D rank.

The method of selecting LED chips having the same emission spectrum as shown in FIG. 18 and the LED chips located close to each other on the wafer as shown in FIG. 19 often have the same emission spectrum. Take advantage of
LEDs located close to each other on the wafer as shown in FIG.
A method of selecting and mounting a chip can be considered.

21 to 24 show how LED chips in the second and third emission wavelength bands are selected and mounted similarly to the LED chips in the first emission wavelength band. A resin on the lens is molded on top of the LED selected in this way mounted on a metal frame and separated into LEs.
D lamp.

The LED lamps thus produced are put together in such a manner that they are marked so that they do not fall apart, are packaged in a lump, or are stored in a continuous area of the reel, and the end surface of the light guide is assembled. It is sent to the next step of assembling the color LED light source by mounting it on.

When combined with a light guide, one color light source device must be preliminarily set to be attached to both ends of the same color LED light source as shown in FIG. 25, or as shown in FIG. The LED lamps that have been divided into groups may be used.

<< Third Embodiment >> In the above-mentioned embodiment, the metal frame type LED lamp in which the LED chip is mounted on the metal frame has been described.
A surface mount type LE in which an LED chip is bonded onto a flat plate substrate 201 which is often seen in a surface mount type package as shown in FIG.
The case of the D lamp will be described.

Although FIG. 27 shows only one LED chip having a light emission wavelength range in one package, as shown in FIG. 28, one package has a plurality of LEDs having different light emission wavelength ranges. It is also possible to put a chip into a unit.

In the case of such a surface mount type LED lamp, the directivity of the light flux is broader as shown in FIG. 29 (b) than in the metal frame type LED lamp shown in FIG. 29 (a). Therefore, the shape of the light guide does not have a simple circular cross section, but the shape shown in FIG. 30 is suitable.

A form using such a light guide is shown in FIG. In FIG. 31, the LED units 11 and 21
Is a unit in which a plurality of surface-mounted LED lamps each containing an LED chip having a different emission wavelength range are soldered onto a printed circuit board to form one unit. It is provided individually.

The light guide 31 is made of a translucent resin such as acrylic resin. Then, the light flux emitted from the LED lamp 1 or 2 from the incident surfaces 41 and 42 is guided by the light guide 3
The light flux that has entered the light guide 1 and propagated through the light guide 31 is reflected by the reflection area 5
It is reflected and confused at and is irradiated toward the outside. In this embodiment, the surface of the translucent member 31 is formed into a minute sawtooth shape, and aluminum is vapor-deposited on the surface to form a reflection region. The reflective film may be formed by coating or printing a light reflective film instead of aluminum vapor deposition. Further, total reflection or Fresnel reflection on the inner surface of the sawtooth portion may be used without forming such a film.

FIG. 32 shows an enlarged view of the LED unit 11. Surface mount type LED lamps 11a, 11b, 11
In c, LED chips in red (R), green (G), and blue (B) emission wavelength ranges, each of which has a different emission wavelength range, are contained. The LED unit 21 also has a similar structure, and has surface-mounted LED lamps 21a, 21b, 21c containing LED chips of R, G, and B emission wavelength regions having different emission wavelength regions.

In the present embodiment as well, similar to the one shown in FIG. 2, the luminous fluxes emitted from the LED units 11 and 12 and made incident on the incident surfaces 41 and 42 of the light guide 31 into the light guide 3. Is repeatedly reflected on the inner surface of the light guide 31 and propagates inside thereof. Then, when light is incident on the reflection area 5 while repeating reflection, the light flux is reflected there, and the light is emitted to the outside with the side facing the area 5 as the emission surface.

In such a structure, the light sources of the respective emission wavelength ranges, that is, L are arranged at the different ends of the light guide 31.
ED lamps 11a, 11b, 11c and 21a, 21
b and 21c are light sources having the same emission wavelength range, that is, LED lamps 11a and 21a, 11b and 21b, 11c.
And 21c are each configured to have an emission spectrum close to each other. In order to configure in this way, the LED lamps may be ranked by the same method as described in the form of the metal frame type LED lamps.

As a method of ranking, the rank of the completed LED unit is defined by a combination of the emission spectrum ranks of the surface-mounted LED lamps of the respective emission wavelength regions, which are soldered thereto, and L is assigned in accordance with the defined rank.
LEDs that belong to the same or close rank are classified into one color light source unit by classifying ED units.
There is a way to get the lamp to be used. Also, in advance, identify the parts that will become LED lamps that will be attached to both ends of the same color LED light source in the future.
The emission spectrum of the surface-mounted LED lamp was measured in advance, and LE of the same emission spectrum was measured in that part.
There is a method of mounting a D chip.

The surface-mount LED lamp is not one in which only one LED chip in the light emission wavelength range is included in one package, but a plurality of LED chips in different light emission wavelength ranges in one package as shown in FIG. In the case where the light source is used as a unit, the metal frame is used even when the light sources of the same emission wavelength range arranged at different ends of the light guide are configured to have emission spectra close to each other. The rank may be divided by a method similar to that of the type LED lamp.

Further, as shown in FIGS. 34 and 35, a method of directly bonding a plurality of LED chips having different emission wavelength ranges onto the printed circuit board can be considered. 34 and 35, the LED units 13 and 23 are
It is an LED unit in which LED chips having emission wavelength regions different from each other are directly bonded onto the printed circuit board 301 to form one unit, and are provided at both ends of the light guide 31. LED chips 1a, 1b,
1c and 2a, 2b and 2c have red, green and blue emission wavelength ranges, respectively. The light guide 31 shown in FIG. 35 is the same as that shown in FIG.

FIG. 36 shows a block diagram of an image reading apparatus using the light source unit as described above. In FIG. 36, the light 9 emitted from the LED lamps 11 and 21 constituting the light source unit, guided by the light guide 31 and reflected therefrom illuminates the original 10 in a line shape. The reflected light from the original 10 is imaged by the unit-magnification optical system 11 on the line sensor 12 formed on the substrate 14 and converted into an image signal. Note that the optical system may not be a unity-magnification optical system as shown in FIG. 36 but may be a reduction optical system as shown in FIG. 37.
Further, as shown in FIGS. 38 and 39, it is also possible to adopt a configuration in which the document to be read is brought into close contact with the sensor formed on the transparent substrate without using a lens through a thin protective film to read the document.

[0063]

As described above, in the image reading apparatus according to the first aspect of the present invention, the plurality of light sources and the plurality of light sources are arranged at different positions to guide the light emitted from the light sources. In the image reading device having the light guide means for illuminating the subject by the above, and the photoelectric conversion means for converting the light from the subject irradiated by the light guide means into an image signal, the light emission wavelength region of the light source is set to a plurality of regions. The plurality of light sources belonging to the same area among the separated areas are classified into a light source that can be used for reading and a light source that cannot be used according to variations in light emission characteristics, and the usable light source is further divided into The illumination state of the subject is made uniform by classifying into a plurality of groups according to the light emission characteristics and arranging light sources belonging to the same group among the plurality of groups at different positions of the light guide means.

Further, in the light source unit usable in the image reading apparatus according to the thirty-ninth aspect, a plurality of light sources and the plurality of light sources are arranged at different positions, and the light emitted from the light sources is guided. And a light guide means for illuminating the subject,
The emission wavelength region of the light source is divided into a plurality of regions, and a plurality of light sources belonging to the same region among the separated regions are classified into a light source that can be used for reading and a light source that cannot be used according to variations in emission characteristics. In addition, the usable light sources are further classified into a plurality of groups according to their light emitting characteristics, and light sources belonging to the same group of the plurality of groups are arranged at different positions of the light guide means, thereby It has become possible to make the irradiation state uniform and perform reading.

Then, not only the light sources belonging to the same emission wavelength region as in claims 1 and 39 are classified into the light sources that can be used for reading and the light sources that cannot be used, but also the usable light sources are grouped. By arranging the light sources belonging to the same group at different positions of the light guide means, it becomes possible to make the irradiation state of the subject uniform.

According to the eleventh aspect of the present invention, in the image reading apparatus, a plurality of LEDs and light guiding means for illuminating an object by arranging the plurality of LEDs at different positions and guiding the light emitted from the LEDs. In an image reading apparatus having a photoelectric conversion unit that converts light from a subject illuminated by the light guiding unit into an image signal, a plurality of LEDs are cut out from the same wafer having variations in light emission characteristics, and the cut LEDs are cut out. The LEDs that can be used for reading and the LEDs that cannot be used are classified according to the variation in the light emission characteristics of the LEDs, and the LEDs that can be used for reading are further classified into a plurality of groups, and the LEDs are classified into the same group among the plurality of groups. By arranging the belonging LEDs at different positions of the light guide means, the irradiation state of the subject is made uniform.

In the light source unit usable in the image reading apparatus according to the forty-ninth aspect, a plurality of LEDs and the plurality of LEDs are arranged at different positions, and the light emitted from the LEDs is guided. It has a light guide that illuminates the subject, and cuts out multiple LEDs from the same wafer that has variations in light emission characteristics. LEDs that can be used for reading are unusable depending on the variations in light emission characteristics of the cut LEDs. The LEDs that can be used for reading are further classified into a plurality of groups, and the LEDs belonging to the same group among the plurality of groups are arranged at different positions of the light guide means, thereby the The irradiation condition was made uniform.

According to the eleventh and forty-ninth aspects, the LED that can be used for reading when the emission characteristics of the LEDs cut out from the wafer have variations.
Not only is the LED classified as an unusable LED, but also usable LEDs are grouped and light sources belonging to the same group are arranged at different positions of the light guide means.
It is now possible to make the irradiation state of the subject uniform and perform reading.

According to the twentieth aspect of the present invention, there are provided a plurality of light sources, light guide means for arranging the plurality of light sources at different positions, and guiding light emitted from the light sources to illuminate an object. In an image reading apparatus having a photoelectric conversion unit that converts light from the subject illuminated by the light guide unit into an image signal, the emission wavelength range of the light source is divided into a plurality of regions, and the same region among the separated regions is used. A plurality of light sources belonging to a region are classified into a first group at the center of variation and second and third groups on both sides thereof according to variations in light emission characteristics, and belong to the same group of the first, second or third groups. By arranging the light sources at different positions of the light guide means, the irradiation state of the subject is made uniform.

Further, in the light source unit usable in the image reading apparatus according to the forty-eighth aspect, a plurality of light sources and the plurality of light sources are arranged at different positions and the light emitted from the light source is guided to the subject. And a light guide means for irradiating the light source, the light emission wavelength range of the light source is divided into a plurality of regions, and a plurality of light sources belonging to the same region among the separated regions are scattered in accordance with variations in light emission characteristics. Irradiation of the object by classifying into a first group and second and third groups on both sides of the first group, and arranging light sources belonging to the same group of the first, second or third groups at different positions of the light guide means. The condition was made uniform.

According to the twentieth and the fifty-eighth aspects, when a plurality of light sources belonging to the same emission wavelength region have variations in light emission characteristics, they are divided into three groups at the center of variation and both sides thereof. By arranging the light sources belonging to the same group at different positions of the light guiding means, it is possible to effectively utilize the light sources other than the central portion of the variation and to make the irradiation state of the subject uniform and perform reading. .

According to the thirtieth aspect of the present invention, in the image reading apparatus, a plurality of LEDs and light guide means for illuminating a subject by guiding the light emitted from the LEDs by disposing the plurality of LEDs at different positions. In an image reading apparatus having a photoelectric conversion unit that converts light from a subject illuminated by the light guiding unit into an image signal, a plurality of LEDs are cut out from the same wafer with variations in light emission characteristics, and the cut LEDs are used. LEDs belonging to the same group of the first, second or third groups are classified into a first group at the center of the variation and a second group and a third group on both sides of the variation according to the light emission characteristics. By arranging in the place, the irradiation state of the said subject was made uniform.

Further, in the light source unit usable in the image reading apparatus according to claim 68, the plurality of LEDs and the plurality of LEDs are arranged at different positions and the light emitted from the LEDs is guided to guide the subject. A plurality of LEDs are cut out from the same wafer having different light emission characteristics, and the cut LEDs are changed in accordance with the light emission characteristics in the first group in the central portion and the second group on both sides thereof.
And the LEDs belonging to the same group of the first, second, or third groups are arranged at different positions of the light guide means to make the irradiation state of the subject uniform.

According to the thirty-eighth and sixty-eighth aspects, when there are variations in the light emission characteristics of the LEDs cut out from the wafer, the variation center is divided into three groups at the center and both sides, and the same group is formed. LED to belong
By arranging the LEDs at different positions of the light guide means, it is possible to effectively utilize the LEDs other than the central portion of the variation and to make the irradiation state of the subject uniform and perform the reading.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an image reading apparatus according to a first embodiment.

FIG. 2 is a configuration diagram of a lighting device according to the first embodiment.

FIG. 3 is a configuration diagram of an LED lamp according to the first embodiment.

FIG. 4 is a diagram illustrating a manufacturing process of the LED lamp according to the first embodiment.

FIG. 5 is a diagram illustrating a manufacturing process of the LED lamp according to the first embodiment.

FIG. 6 is a diagram illustrating a manufacturing process of the LED lamp according to the first embodiment.

FIG. 7 is a diagram illustrating a manufacturing process of the LED lamp according to the first embodiment.

FIG. 8 is a diagram illustrating a manufacturing process of the LED lamp according to the first embodiment.

FIG. 9 is a diagram illustrating a manufacturing process of the LED lamp according to the first embodiment.

FIG. 10 is a diagram illustrating a manufacturing process of the LED lamp according to the first embodiment.

FIG. 11 is an explanatory diagram of a method for measuring an emission spectrum of the LED lamp according to the first embodiment.

FIG. 12 is a diagram illustrating a combination of LED lamps according to the first embodiment.

FIG. 13 is a spectrum distribution diagram of the lighting device according to the first embodiment.

FIG. 14 is a distribution chart of ranks of light emission characteristics of LED lamps.

FIG. 15 is a configuration diagram of the image reading apparatus according to the first embodiment.

FIG. 16 is a diagram illustrating a manufacturing process of the LED lamp according to the second embodiment.

FIG. 17 is a diagram illustrating a manufacturing process of the LED lamp according to the second embodiment.

FIG. 18 is a diagram illustrating a manufacturing process of the LED lamp according to the second embodiment.

FIG. 19 is a diagram illustrating a manufacturing process of the LED lamp according to the second embodiment.

FIG. 20 is a diagram illustrating a manufacturing process of the LED lamp according to the second embodiment.

FIG. 21 is a diagram illustrating a manufacturing process of the LED lamp according to the second embodiment.

FIG. 22 is a diagram illustrating a manufacturing process of the LED lamp according to the second embodiment.

FIG. 23 is a diagram illustrating a manufacturing process of the LED lamp according to the second embodiment.

FIG. 24 is a diagram illustrating a manufacturing process of the LED lamp according to the second embodiment.

FIG. 25 is a diagram illustrating a combination of LED lamps according to the second embodiment.

FIG. 26 is a diagram illustrating a combination of LED lamps according to the second embodiment.

FIG. 27 is a configuration diagram of an LED lamp according to a third embodiment.

FIG. 28 is a configuration diagram of an LED lamp according to a third embodiment.

FIG. 29: Metal frame type LED lamp and surface mount type L
It is a figure which shows the directional characteristic of an ED lamp.

FIG. 30 is a configuration diagram of a light guide according to a third embodiment.

FIG. 31 is a configuration diagram of an illumination device according to a third embodiment.

FIG. 32 is a configuration diagram of an LED unit according to a third embodiment.

FIG. 33 is a configuration diagram of an LED unit according to a third embodiment.

FIG. 34 is a configuration diagram of an LED unit according to a third embodiment.

FIG. 35 is a configuration diagram of an illumination device according to a third embodiment.

FIG. 36 is a configuration diagram of an image reading device according to a third embodiment.

FIG. 37 is a configuration diagram of an image reading device according to a third embodiment.

FIG. 38 is a configuration diagram of an image reading device according to a third embodiment.

FIG. 39 is a configuration diagram of an image reading device according to a third embodiment.

FIG. 40 is a configuration diagram of a conventional image reading apparatus.

FIG. 41 is a configuration diagram of a conventional image reading apparatus.

FIG. 42 is a configuration diagram of a conventional lighting device.

FIG. 43 is a configuration diagram of a conventional lighting device.

FIG. 44 is a configuration diagram of a conventional LED lamp.

FIG. 45 is an illuminance distribution diagram of a conventional lighting device.

FIG. 46 is a configuration diagram of a conventional lighting device.

FIG. 47 is an illuminance distribution diagram of a conventional lighting device.

FIG. 48 is a spectrum distribution diagram of a conventional lighting device.

[Explanation of symbols]

 1 LED lamp 2 LED lamp 3 Light guide 11 LED unit 12 Line sensor 21 LED unit 31 Light guide

Claims (82)

[Claims] 1. A plurality of light sources, a light guide unit for arranging the plurality of light sources at different positions and for guiding the light emitted from the light source to illuminate an object, and the light guide unit for irradiating the subject. An image reading apparatus having a photoelectric conversion means for converting light from an object into an image signal, wherein the emission wavelength region of the light source is divided into a plurality of regions, and a plurality of light sources belonging to the same region among the separated regions are emitted. The light sources usable for reading and the light sources that cannot be used are classified according to the variation of the characteristics, and further, the usable light sources are classified into a plurality of groups according to the emission characteristics thereof, and among the plurality of groups. An image reading apparatus, wherein light sources belonging to the same group are arranged at different positions of the light guide means so that the irradiation state of the subject is made uniform. 2. The image reading device according to claim 1, wherein the light guide means is formed of a light transmissive resin. 3. The image reading apparatus according to claim 1, wherein the plurality of light sources are light sources belonging to a plurality of different emission wavelength regions. 4. The image reading apparatus according to claim 3, wherein a plurality of light sources belonging to different emission wavelength regions are arranged at the same position of the light guide means. 5. The image reading device according to claim 1, wherein the light sources belonging to the same emission wavelength region can be turned on at the same time. 6. The image reading device according to claim 3, wherein the light sources belonging to the different emission wavelength regions can be independently turned on. 7. The image reading device according to claim 6, wherein a plurality of light sources belonging to the different emission wavelength regions can be sequentially turned on. 8. The image reading device according to claim 3, wherein the plurality of light sources include red, green, and blue light sources. 9. The image reading device according to claim 1, wherein the plurality of light sources include LEDs. 10. The image reading apparatus according to claim 1, wherein the light guide unit irradiates the subject in a line shape, and the photoelectric conversion unit is a line sensor. 11. A plurality of LEDs, light guide means for illuminating a subject by arranging the plurality of LEDs at different positions and guiding light emitted from the LEDs, and the light guide means for irradiating the subject. In an image reading apparatus having a photoelectric conversion means for converting light from an object into an image signal, a plurality of LEDs are cut out from the same wafer having variations in light emission characteristics, and read according to variations in light emission characteristics of the cut LEDs. LEDs that can be used for reading and those that cannot be used are classified into LEDs that cannot be used.
Image reading, characterized in that EDs are classified into a plurality of groups, and LEDs belonging to the same group among the plurality of groups are arranged at different positions of the light guide means to make the irradiation state of the subject uniform. apparatus. 12. The image reading device according to claim 11, wherein the light guide unit is formed of a light transmissive resin. 13. The plurality of LEs according to claim 11.
An image reading device characterized in that D is composed of a plurality of LEDs belonging to different emission wavelength regions. 14. The LED according to claim 13, which belongs to the same portion of the light guide means and belongs to different emission wavelength regions.
An image reading apparatus having a plurality of arranged. 15. The image reading apparatus according to claim 11, wherein the LEDs belonging to the same emission wavelength region can be turned on at the same time. 16. The image reading apparatus according to claim 13, wherein the LEDs belonging to the different emission wavelength regions can be turned on independently. 17. The image reading device according to claim 16, wherein a plurality of LEDs belonging to the different emission wavelength regions can be sequentially turned on. 18. The image reading apparatus according to claim 13, wherein the plurality of LEDs include red, green, and blue light sources. 19. The image reading device according to claim 11, wherein the light guide unit irradiates the subject in a line shape, and the photoelectric conversion unit is a line sensor. 20. A plurality of light sources, a light guide means for illuminating a subject by arranging the plurality of light sources at different locations and guiding light emitted from the light source, and a subject illuminated by the light guide means. In an image reading apparatus having a photoelectric conversion unit that converts light from an image signal into an image signal, the emission wavelength range of the light source is divided into a plurality of regions, and a plurality of light sources that belong to the same region among the separated regions have emission characteristics. According to the variation of the first group in the central portion of the variation and the second and third groups on both sides thereof,
Alternatively, the image reading device is characterized in that the light sources belonging to the same group of the third group are arranged at different positions of the light guide means to make the irradiation state of the subject uniform. 21. The image reading device according to claim 20, wherein the light guide unit is formed of a light transmissive resin. 22. The image reading apparatus according to claim 21, wherein the plurality of light sources are light sources belonging to a plurality of different emission wavelength regions. 23. The image reading device according to claim 22, wherein a plurality of light sources belonging to different emission wavelength regions are arranged at the same location of the light guide means. 24. The image reading device according to claim 20, wherein light sources belonging to the same emission wavelength region can be turned on at the same time. 25. The image reading device according to claim 22, wherein the light sources belonging to the different emission wavelength regions can be turned on independently. 26. The image reading apparatus according to claim 25, wherein a plurality of light sources belonging to the different emission wavelength regions can be sequentially turned on. 27. The image reading apparatus according to claim 22, wherein the plurality of light sources include red, green, and blue light sources. 28. The image reading device according to claim 20, wherein the plurality of light sources include LEDs. 29. The image reading device according to claim 20, wherein the light guide unit irradiates the subject in a line shape, and the photoelectric conversion unit is a line sensor. . 30. A plurality of LEDs, a light guide means for illuminating a subject by arranging the plurality of LEDs at different positions and guiding light emitted from the LEDs, and a subject illuminated by the light guide means. In an image reading apparatus having a photoelectric conversion means for converting light from the image signal into an image signal, a plurality of LEDs are cut out from the same wafer having variations in light emission characteristics, and the cut LEDs are varied in accordance with the light emission characteristics. The first group and the second and third groups on both sides of the first group are classified, and LEDs belonging to the same group of the first, second, or third groups are arranged at different positions of the light guide unit, so that the LEDs of the subject are separated. An image reading device having a uniform irradiation state. 31. The image reading device according to claim 30, wherein the light guide unit is formed of a light transmissive resin. 32. The plurality of LEs according to claim 30,
An image reading device characterized in that D is composed of a plurality of LEDs belonging to different emission wavelength regions. 33. The LEDs according to claim 32, which belong to different light emission wavelength regions at the same portion of the light guide means.
An image reading apparatus having a plurality of arranged. 34. The image reading device according to claim 30, wherein LEDs belonging to the same emission wavelength region can be turned on at the same time. 35. The image reading device according to claim 32, wherein the LEDs belonging to the different emission wavelength regions can be turned on independently. 36. The image reading device according to claim 35, wherein a plurality of LEDs belonging to the different emission wavelength regions can be sequentially turned on. 37. The image reading device according to claim 32, wherein the plurality of LEDs include red, green, and blue light sources. 38. The image reading device according to claim 30, wherein the light guide unit irradiates the subject in a line shape, and the photoelectric conversion unit is a line sensor. 39. A light emission wavelength of the light source, comprising: a plurality of light sources; and a light guide means for arranging the plurality of light sources at different positions to guide light emitted from the light source to illuminate a subject. The area is divided into a plurality of areas, and a plurality of light sources belonging to the same area among the separated areas are classified into a light source that can be used for reading and a light source that cannot be used according to variations in emission characteristics. Possible light sources are classified into a plurality of groups according to their light emission characteristics, and light sources belonging to the same group among the plurality of groups are arranged at different positions of the light guide means to make the irradiation state of the subject uniform. A light source unit that can be used in an image reading device characterized by the above. 40. The light source unit according to claim 39, wherein the light guide means is formed of a light transmissive resin. 41. The light source unit according to claim 39, wherein the plurality of light sources are light sources belonging to a plurality of different emission wavelength regions. 42. The light source unit according to claim 41, wherein a plurality of light sources belonging to different emission wavelength regions are arranged at the same position of the light guide means. 43. The light source unit according to claim 39, wherein the light sources belonging to the same emission wavelength region can be turned on at the same time. 44. The light source unit according to claim 41 or 42, wherein the light sources belonging to the different emission wavelength regions can be independently turned on. 45. A light source unit according to claim 44, wherein a plurality of light sources belonging to the different emission wavelength regions can be sequentially turned on. 46. The light source unit according to claim 41, 42, 44 or 45, wherein the plurality of light sources include red, green and blue light sources. . 47. The light source unit according to claim 39, wherein the plurality of light sources include LEDs. 48. The light source unit according to claim 39, wherein the light guide unit illuminates the subject in a line shape. 49. A plurality of LEDs, and light guide means for illuminating a subject by arranging the plurality of LEDs at different positions and guiding light emitted from the LEDs. A plurality of LEDs are cut out from one and the same wafer, and LEDs that can be used for reading and LEDs that cannot be used are classified according to variations in the emission characteristics of the cut LEDs.
Image reading, characterized in that EDs are classified into a plurality of groups, and LEDs belonging to the same group among the plurality of groups are arranged at different positions of the light guide means to make the irradiation state of the subject uniform. Light source unit that can be used in the device. 50. The light source unit according to claim 49, wherein the light guide means is formed of a light transmissive resin. 51. The plurality of LEs according to claim 49.
A light source unit that can be used in an image reading apparatus, characterized in that D is composed of a plurality of LEDs belonging to different emission wavelength regions. 52. The LEDs according to claim 51, which belong to different light emission wavelength regions at the same portion of the light guide means.
A light source unit that can be used in an image reading apparatus, in which a plurality of light source units are arranged. 53. A light source unit according to any one of claims 49 to 52, wherein the LEDs belonging to the same emission wavelength region can be turned on at the same time. 54. The light source unit according to claim 51 or 52, wherein the LEDs belonging to the different emission wavelength regions can be turned on independently of each other. 55. The light source unit according to claim 54, wherein a plurality of LEDs belonging to the different emission wavelength regions can be sequentially turned on. 56. The light source unit according to claim 51, 52, 54 or 55, wherein the plurality of LEDs include red, green and blue light sources. . 57. The light source unit according to claim 49, wherein the light guide unit irradiates the subject in a line shape. 58. A light emission wavelength range of the light source, comprising: a plurality of light sources; and a light guide means for arranging the plurality of light sources at different positions to guide light emitted from the light source to illuminate a subject. Is divided into a plurality of regions, and a plurality of light sources belonging to the same region among the separated regions are classified into a first group at the center of variation and second and third groups on both sides thereof according to variations in light emission characteristics, The first and second
Alternatively, a light source unit that can be used in an image reading apparatus, in which light sources belonging to the same group of the third group are arranged at different positions of the light guide unit so that the irradiation state of the subject is made uniform. 59. The light source unit according to claim 58, wherein the light guide means is formed of a light transmissive resin. 60. The light source unit according to claim 59, wherein the plurality of light sources are light sources belonging to a plurality of different emission wavelength regions. 61. The light source unit according to claim 60, wherein a plurality of light sources belonging to different emission wavelength regions are arranged at the same location of the light guide means. 62. A light source unit according to claim 58, wherein light sources belonging to the same emission wavelength region can be turned on at the same time. 63. The light source unit according to claim 60 or 61, wherein the light sources belonging to the different emission wavelength regions can be independently turned on. 64. The light source unit according to claim 63, wherein a plurality of light sources belonging to different emission wavelength regions can be sequentially turned on. 65. The light source unit according to claim 60, 61, 63 or 64, wherein the plurality of light sources include red, green and blue light sources. . 66. The light source unit according to claim 58, wherein the plurality of light sources include LEDs. 67. The light source unit according to claim 58, wherein the light guide unit illuminates the subject in a line shape. 68. A plurality of LEDs and light guide means for irradiating a subject by arranging the plurality of LEDs at different positions and guiding light emitted from the LEDs are provided, and light emission characteristics vary. A plurality of LEDs are cut out from the same wafer, and the cut LEDs are classified into a first group at the center of variation and second and third groups on both sides thereof according to the light emission characteristics. An illumination unit that can be used in an image reading device, wherein LEDs belonging to the same group of three groups are arranged at different positions of the light guide means to make the irradiation state of the subject uniform. 69. The light source unit according to claim 68, wherein the light guide means is formed of a light transmissive resin. 70. The plurality of LEs according to claim 69.
A light source unit that can be used in an image reading apparatus, characterized in that D is composed of a plurality of LEDs belonging to different emission wavelength regions. 71. The LEDs according to claim 69, which belong to different light emission wavelength regions at the same portion of the light guide means.
A light source unit that can be used in an image reading apparatus, in which a plurality of light source units are arranged. 72. A light source unit according to any one of claims 68 to 71, wherein the LEDs belonging to the same emission wavelength region can be turned on at the same time. 73. The light source unit according to claim 70 or 71, wherein the LEDs belonging to the different emission wavelength regions can be turned on independently of each other. 74. The light source unit according to claim 73, wherein a plurality of LEDs belonging to the different emission wavelength regions can be sequentially turned on. 75. The light source unit according to claim 70, 71, 73 or 74, wherein the plurality of LEDs include red, green and blue light sources. . 76. The light source unit according to claim 68, wherein the light guide unit irradiates the subject in a line shape. 77. The image reading device according to claim 1, wherein the emission characteristic is an emission spectrum. 78. The image reading device according to claim 1, wherein the light emission characteristic is light emission efficiency. 79. The image reading device according to claim 1, wherein the light emission characteristic is a light emission amount. 80. The light source unit according to claim 39, wherein the light emission characteristic is an emission spectrum. 81. A light source unit according to any one of claims 39 to 76, wherein the light emission characteristic is light emission efficiency. 82. The light source unit according to claim 39, wherein the light emission characteristic is a light emission amount.