JPH10276298A - Linear light source device, image reader provided with it and resin package type led light source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a high difference from being caused in an emission luminous amount of each color light and a luminous quantity distribution in the case that each of R, G, B color lights emitted from a LED light source is linearly emitted to desired regions through the use of a light guide member, to make the light guide member small and to improve the assembling work performance or the like of the LED light source to the light guide member. SOLUTION: The linear light source device is provided with a light source that emits each of R, G, B color lights and with a light guide member 1 that disperses a light emitted from the light source and made incident into the inside in strips to emit the strips almost from the entire length of a light emission face 12 with a prescribed length, and a 1-package LED light source 3 resin- packaging three kinds of LED chips emitting each of R, G, B color lights altogether is adopted for the light source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear light source device used for illumination of a document in a so-called contact image scanner, an image reading device provided with the linear light source device, and a resin usable for the linear light source device. Package type LE
D light source.

[0002]

2. Description of the Related Art Conventionally, as an example of a linear light source device, there is one described in, for example, JP-A-6-217084. The linear light source device described in the publication is shown in FIG.
As shown in (1), R, G, B (red, green, blue (the same applies hereinafter in the present invention)) are provided on end surfaces 15e, 15e at both ends in the longitudinal direction of the light guide member 1e made of a transparent member.
Three types of LED light sources 9 (9A to 9A)
C) are opposed to each other. These three types of LEDs
Each of the light sources 9A to 9C emits light of a desired color.
Two LED chips (not shown) are individually resin-packaged, and are arranged in a line in the width direction of the light guide member 1e. On the other hand, in the light guide member 1e, one side surface extending in the longitudinal direction is a light exit surface 12e, and a side surface facing the light exit surface in the thickness direction is a light diffuse reflection surface 14e. Other aspects of 19,1
9 and the light emitting surface 12e are mirror-like flat surfaces.

In the linear light source device having the above-described structure, as shown in FIG. 14, light incident on the inside of the light guide member 1e from the end surfaces 15e, 15e of the light guide member 1e is transmitted to the center of the light guide member 1e in the longitudinal direction. By causing these lights to diffusely reflect on the light diffusely reflecting surface 14e while traveling to the portion side, the light that has been diffusely reflected can be emitted from the light emitting surface 12e to the outside. Therefore, the surface of the document K can be irradiated with light in a linear manner. Therefore, the image reading apparatus using the linear light source device can read the image of the document K line by line. Also, as the light source,
Since three types of LED light sources 9A to 9C are used, it is possible to cope with reading of a so-called color image. In the linear light source device described above, it is not necessary to arrange a large number of point light sources in a straight line along the longitudinal direction of the reading line of the document K, and the number of LED light sources can be reduced. Can be achieved.

[0004]

However, the conventional linear light source device has the following disadvantages.

That is, in the above-described conventional linear light source device,
A total of three LED light sources 9A to 9C are used as light sources for allowing light to enter the light guide member 1e, and these LED light sources 9A to 9C are arranged in the width direction of the light guide member 1e. For this reason, the width of the light guide member 1e must necessarily be equal to or greater than the total width of the three LED light sources 9A to 9C in total. As a result, in the related art, the width of the light guide member 1e is limited, and it is difficult to reduce the size of the light guide member 1e. Had a problem that the size of the device became large.

Conventionally, as shown in FIG. 15, a total of three LED light sources 9A to 9C are connected to the end face 15 of the light guide member 1e.
e and 15e, one LED light source 9B can be arranged at the center in the width direction of the light guide member 1e, but the other two LED light sources 9A and 9C have the width of the light guide member 1e. It will be located at a considerable distance from the center of the direction. Therefore, the above three LEDs
When each of the light sources 9A to 9C emits light, the traveling paths of the R, G, and B lights emitted from the LED light sources 9A to 9C when traveling inside the light guide member 1e are different from each other. Becomes Such a difference in the traveling path of light leads to non-uniformity in the amount of light emitted from the light emitting surface 12e of the light guide member 1e and in the light amount distribution. In particular, conventionally, the light emitted from the two LED light sources 9A and 9C located at both ends in the width direction of the light guide member 1e is smaller than the light emitted from the single LED light source 9B located at the center. Light was easily leaked to the outside through the side surfaces 19, 19 of the light guide member 1e, and the amounts of the R, G, and B lights emitted from the light emission surface 12e were more uneven. As a result, conventionally, when the color image of the document K is read by the image reading device, the color tone of the read image is actually changed due to the uneven illuminance of the light of each color of R, G, and B. The color tone of the original image is greatly different from that of the original image, and the quality of the read image deteriorates. As means for solving such a problem, image data processing for correcting the color tone of the read image may be performed. However, such image data processing is difficult, and a dedicated circuit for the processing is very expensive. .

Furthermore, conventionally, a total of three LED light sources 9
A to 9C are used, and the number of components of these LED light sources is large. Therefore, it is not easy to assemble the LED light sources 9A to 9C at predetermined positions, and there is still room for improvement in this respect.

The present invention was conceived under such circumstances, and the R and R emitted from the LED light source were developed.
When linearly irradiating light of each color of G and B to a desired region using a light guide member, appropriate image reading is performed so that there is no large difference between the emission light amount and light amount distribution of each color light. It is an object of the present invention to reduce the size of the light guide member and improve the workability of assembling the LED light source to the light guide member.

[0009]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

According to a first aspect of the present invention, a linear light source device is provided. The linear light source device includes a light source that emits light of each color of R, G, and B, and a light emission surface having a predetermined length by dispersing the light emitted from the light source and entering the inside into a band shape, over a substantially entire area. A light guide member that emits light from the light source, wherein the light source is a one-package type in which three types of LED chips that emit light of each color of R, G, and B are collectively resin-packaged. LED light source.

According to a second aspect of the present invention, there is provided a resin package type LED light source. This resin-packaged LED light source is characterized in that three types of LED chips that emit light of each color of R, G, and B are collectively resin-packaged. This resin package type LE
The D light source can be suitably used as a one-package LED light source of the linear light source device provided by the first aspect of the present invention.

According to the present invention, there is provided a one-package LED light source in which three types of LED chips that emit light of R, G, and B colors are collectively packaged with a resin. In order for the light of each color of R, G, and B emitted from the light source to enter the light guide member, for example, the width of the light guide member is set to the one-package LE.
The width may be set to be substantially the same as the width of the D light source. On the other hand, the one-package LED light source has three types of L light sources.
The ED chips can be packaged together in a resin with good space efficiency, and the overall size can be reduced to, for example, the same small size as the conventional one in which only one LED chip is resin-packaged. .
Therefore, in the present invention, compared with the conventional means in which a total of three LED light sources having a predetermined size are arranged in the width direction of the light guide member, the width of the light guide member is reduced to about 1/3 of the width. The light guide member can be made considerably thin. as a result,
The effect is obtained that the overall size of the linear light source device can be reduced, and that the image reading device and other various devices incorporating the linear light source device can be reduced in size.

Further, as an important effect, in the one-package type LED light source used in the present invention,
It is also possible to make the three types of LED chips that emit light of each color of R, G and B very close to each other. Therefore, when light of each color of R, G, and B is made to enter the inside of the light guide member in a state where the one-package type LED light source is opposed to a predetermined position of the light guide member, the R, G , B
It is possible to cause the light of each color to travel through almost the same path without exiting from the light traveling path of each color, and then to emit the light from the light exit surface of the light guide member. Therefore, differently from the related art, it is also possible to equalize the emission light amount and the light amount distribution of the light of each color of R, G, and B. As a result, when the linear light source device according to the present invention is used as a light source device for reading an image, the color tone of the read image can be made closer to the color tone of the actual original image, and the quality of the read image can be improved. The effect that can be obtained is also obtained. Further, according to the present invention, unlike the related art, there is no need to provide a dedicated circuit for correcting the color tone of the read image, which is advantageous in reducing the manufacturing cost of the entire image reading apparatus.

Further, according to the present invention, the work of assembling the LED light source of one package type at a predetermined position in association with the light guide member can be performed more easily than the work of assembling the conventional three LED light sources. The manufacturing operation of the shaped light source device is also facilitated.

In a preferred embodiment of the present invention, the light guide member has a first side surface among a plurality of outer peripheral side surfaces extending in a longitudinal direction thereof as the light exit surface, and the light guide member has a light exit surface. Any part of the outer surface other than the surface is a light incident portion where light is incident from the light source into the light guide member, and the light incident into the light guide member from the light incident portion is the light incident portion. The one-pack type L is configured to be emitted from the light emitting surface while being reflected by a plurality of outer peripheral side surfaces and traveling in the longitudinal direction thereof.
The ED light source may be configured to face a central portion in the lateral direction of the light guide member in the light incident portion.

According to such a configuration, light of each color of R, G, B emitted from the LED light source of one package type is
The light guide member can be made to enter the inside of the light guide member from the central portion in the short direction (width direction or thickness direction) of the light guide member, and then the light is made to travel in the longitudinal direction inside the light guide member. The light can be efficiently emitted from the emission surface. For example, if the light emitted from the LED light source is incident on the inside of the light guide member from a position far away from the center of the light guide member in the lateral direction, most of the light leaks to the outside of the light guide member. However, according to the above configuration, such a problem can be suppressed.

According to a third aspect of the present invention, there is provided a linear light source device having a configuration different from that of the linear light source device provided by the first aspect of the present invention. The linear light source device includes a light source that emits light of each color of R, G, and B, and a light emission surface having a predetermined length by dispersing the light emitted from the light source and entering the inside into a band shape, over a substantially entire area. And a light guide member that emits light from the light source device, wherein the light source is:
Of the three types of LED chips that emit light of each color of R, G, and B, a first LED light source in which two types of LED chips are collectively resin-packaged, and the remaining one type of LED chip are the first type LED chip. The LED light source is characterized by being combined with a second LED light source individually packaged with resin.

According to a fourth aspect of the present invention, there is provided a resin package type LED light source. This resin-packaged LED light source is characterized in that two types of LED chips that emit light of two colors of light of three colors of R, G, and B are collectively resin-packaged. This resin package type LED light source can be suitably used as the first LED light source of the linear light source device provided by the third aspect of the present invention.

In the present invention, a first LED light source in which two types of LED chips that emit light of two colors of R, G, and B are collectively resin-packaged, and emits light of another one color. A light source in which a second LED light source is combined is provided, and light of each color of R, G, and B emitted from the first LED light source and the second LED light source is made to enter the light guide member. For example, the width of the light guide member may be set to be substantially the same as the total size of the two LED light sources, the first LED light source and the second LED light source. On the other hand, the first LED light source is capable of resin packaging two types of LED chips together in a space-efficient manner, and the overall size of the first LED light source is the same as that of a conventional LED package having only one LED chip. It is possible to have a small size approximately equal to the one.
Therefore, similarly to the linear light source device provided by the first aspect of the present invention, a light guide is compared with a conventional means in which a total of three LED light sources of a predetermined size are arranged in the width direction of the light guide member. The width dimension or thickness dimension of the member can be considerably reduced, so that the size of the entire linear light source device can be reduced, and the image reading device and other various devices in which the linear light source device is incorporated can be reduced. Is obtained.

In the present invention, the first LED light source and the second LED light source are brought closer to each other,
Again, three types of LED chips that emit light of each color of R, G, and B can be brought close to each other. Therefore, when light of each color of R, G, and B is made to enter the inside of the light guide member, similarly to the linear light source device provided by the first aspect of the present invention, the R, G, and B light are emitted. In order not to cause a large difference in the traveling path of the light of each color B,
It is possible to equalize the amount of emitted light and the distribution of the amount of light of each color of R, G, and B, which is useful for improving the quality of a read image. Further, since the number of LED light sources can be reduced as compared with the related art, the assembling work is also facilitated.

In a preferred embodiment of the present invention, the light guide member has a first side surface among a plurality of outer peripheral side surfaces extending in a longitudinal direction thereof as the light exit surface, and the light guide member has a light exit surface. Any part of the outer surface other than the surface is a light incident portion where light is incident from the light source into the light guide member, and the light incident into the light guide member from the light incident portion is the light incident portion. The first LED light source and the second LED light source are configured to be emitted from the light emitting surface while traveling in the longitudinal direction while being reflected by the plurality of outer peripheral side surfaces. The light guide member may be arranged symmetrically with respect to the center of the light guide member in the lateral direction.

According to such a configuration, the two-color light emitted from the first LED light source and the one-color light emitted from the second LED light source are transmitted in the width direction or the thickness direction of the light guide member. Can be made to enter the inside of the light guide member without being largely deviated from the center portion in the short direction of the light guide member, and then the light can be efficiently emitted from the light exit surface while traveling inside the light guide member in the longitudinal direction. You can do it. For example, if one of the first LED light source and the second LED light source is provided at a position that is farther deviated from the center in the width direction of the light guide member than the other, the light is emitted from the first LED light source. Although the traveling paths of the light and the light emitted from the second LED light source are different, and the amount of light leaking to the outside of the light guide member is different, the difference in the amount of light emitted from the light exit surface is likely to occur. According to the above configuration, such a problem can be avoided.

In another preferred embodiment of the present invention,
The light guide member may be configured to further include another light guide member that causes light emitted from the light exit surface of the light guide member to travel along a predetermined path and irradiates the light linearly to a predetermined position.

According to such a configuration, light emitted from the light exit surface of the light guide member can be guided to a predetermined position by using another light guide member. In the case of irradiating light, it is not necessary to make the light exit surface of the light guide member directly face the image reading area. Therefore, it is possible to give flexibility to the mounting posture of the light guide member having the light emitting surface, and to assemble the light guide member and to use the LED.
It is possible to facilitate the arrangement of the light source and the like.

According to a fifth aspect of the present invention, there is provided an image reading apparatus. This image reading device irradiates a predetermined image reading surface with light from a light source device,
An image reading apparatus, wherein reflected light from an image reading object on a reading line of the image reading object disposed opposite to the image reading surface is received by a plurality of light receiving elements arranged in the reading line direction. The light source device is characterized in that the linear light source device provided by the first or third aspect of the present invention is used.

In the image reading apparatus according to the present invention, the same effects as those obtained by the linear light source device provided by the first or third aspect of the present invention can be expected.
The overall size of the apparatus can be reduced, and the quality of the read image can be improved.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a front view showing an example of a linear light source device A according to the present invention. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a sectional view taken along line III-III of FIG.

The linear light source device A shown in FIG.
And an LED light source 3 for entering light inside the light guide member 1
Are provided. The LED light source 3 corresponds to the resin package type LED light source and the one package type LED light source according to the present invention.

The light guide member 1 is a transparent member 10 obtained by molding an acrylic transparent resin such as PMMA.
Occupy the main part. The light guide member 1 has a bar shape having a certain dimension in the longitudinal direction, and has a first side surface 10A, a second side surface 10B, a third side surface 10C, a fourth side surface 10D extending in the longitudinal direction, and end surfaces at both ends in the longitudinal direction. 10E, 1
0F. The first side surface 10A and the second side surface 10
B faces the light guide member 1 in the vertical thickness direction, and the third side face 10C and the fourth side face 10D face each other in the width direction of the light guide member 1. As is best seen in FIG.
The width dimension b1 of the light guide member 1 is equal to the width of the LED light source 3,
Alternatively, the dimensions are slightly wider.

The first side surface 10A is, as described later,
The entire length region is a portion serving as the light emitting surface 12, and is preferably a mirror-like plane. Similarly, the third side surface 10C and the fourth side surface 10D are also mirror-like planes. Note that the mirror-like plane does not necessarily need to be a plane whose surface is actively polished. For example, in the case where the light guide member 1 is molded with a resin using a resin, a relatively smooth surface obtained by the resin molding is also included in the mirror-like plane. If the surface of the transparent member is a mirror-like flat surface, all light rays incident on the surface at an angle larger than the total reflection critical angle specified by the material of the transparent member can be totally reflected. On the other hand, light rays incident at an angle smaller than the critical angle for total reflection can be transmitted through the surface.

At the center of the first side surface 10A in the longitudinal direction, there is provided a substantially V-shaped concave portion 11 as viewed from the front. The recess 11 forms two inclined surfaces 11a, 11a, and these two inclined surfaces 11a, 11a are also mirror-like. As shown in FIG. 6, each of the inclined surfaces 11 a reflects light emitted from the LED light source 3 and incident on the inside of the light guide member 1 so as to travel toward both ends in the longitudinal direction of the light guide member 1. It is the part that plays a role. In the present embodiment, each of the inclined surfaces 11a is a convex curved surface, and a series of surfaces capable of totally reflecting light emitted from the LED light source 3 as a point light source disposed at a predetermined position are connected. The surface is equal to.

A concave portion 16 is formed at the center in the longitudinal direction of the second side surface 10 B, and the portion where the concave portion 16 is formed is a light incident portion 15. The recess 16 is LE
The size is such that the D light source 3 can be arranged inside the
The ED light source 3 has a substantially trapezoidal cross-section that becomes narrower as it goes to the back so as to facilitate the insertion positioning of the ED light source 3.
The recess 16 faces the center of the recess 11.

A plurality of concave portions 14 are provided at appropriate intervals in a region of the second side surface 10B other than the light incident portion 15. The region between the plurality of concave portions 14 is a mirror-shaped flat portion 13. The plurality of concave portions 14 serve to rapidly change the traveling angle of light traveling inside the light guide member 1 and emit the light from the first side surface 10A, and have, for example, an arc-shaped cross section and a curved surface. Inclined surface 14a. In addition, the second side surface 10
B is an inclined surface that gradually reduces the thickness of the light guide member 1 from the center in the longitudinal direction to both ends in the longitudinal direction. It is preferable that the second side surface 10B has such an inclined surface, since light traveling from the central portion in the longitudinal direction of the light guide member 1 to both ends in the longitudinal direction can be efficiently incident on the inclined surface 14a. . However, the present invention is not limited to this, and the second side surface 10B is replaced with the first side surface 10A.
The plane may be substantially parallel to the plane.

The light guide member 1 plays a role of dispersing the light emitted from the LED light source 3 in a strip shape and then emitting the light from the entire length of the light emitting surface 12 (first side surface 10A). Specifically, as shown in FIG. 6, when the LED light source 3 emits light in a state where the LED light source 3 is arranged in the concave portion 16, the light is transmitted from the light incident portion 15 into the light guide member 1. It enters with an appropriate spread angle. Many of the above lights are
It reaches the two inclined surfaces 11 a of the recess 11.
However, since these inclined surfaces 11a, 11a are inclined with respect to the longitudinal direction of the light guide member 1, it is necessary to increase the incident angle of light that directly reaches the respective inclined surfaces 11a from the LED light source 3. The angle of incidence of the transparent member 10
Can be larger than a predetermined total reflection critical angle specified by the material. Therefore, most of the light that has entered the light guide member 1 from the LED light source 3
a, 11a is prevented from leaking to the outside as it is. As means for surely preventing light incident into the light guide member 1 from passing through the inclined surfaces 11a and 11a and leaking to the outside as it is, for example, the inclined surface 1
Means of covering the whole or a part of 1a and 11a with a light reflecting material or a light reflecting member may be adopted. Specific means include, for example, means for applying a light reflecting material such as metal to the inclined surface 11a by vapor deposition or sputtering, means for applying a light reflecting paint, and attaching a light reflecting film or tape to the inclined surface 11a. Means and the like can be adopted. Further, each of the inclined surfaces 11a may be, for example, a planar inclined surface instead of a convex curved surface.

In FIG. 6, most of the light incident on the light guide member 1 is eventually totally reflected by the inclined surfaces 11a, 11a and travels in the longitudinal direction of the light guide member 1. Then, the first side surface 10A, the second side surface 10B, and the third side surface 10
C, and reaches both ends in the longitudinal direction of the light guide member 1 while repeating total reflection at various points on the fourth side surface 10D.
If the end faces 10E and 10F of the light guide member 1 are covered with a light reflecting material or a light reflecting member, light will
It is also possible to properly solve the problem that the light passes through E and 10F and leaks to the outside. When the light travels through the light guide member 1, although the light is totally reflected in the flat portion 13 of the second side surface 10 </ b> B, the inclined surface 14 of the concave portion 14 is formed.
Most of the light incident on a is reflected in a form close to scattered reflection, and the course of the light is rapidly changed. Then, the first
It is more likely that light will enter the side surface 10A at an incident angle smaller than the critical angle for total reflection. Therefore, most of the light reflected by the inclined surface 14a and traveling in the direction of the first side surface 10A passes through the first side surface 10A as it is and is emitted to the outside of the light guide member 1. Therefore, even though the light incident portion 15 is provided at the central portion in the longitudinal direction of the light guide member 1, light can be emitted almost uniformly from the entire length region of the light exit surface 12 (first side surface 10A). Become.

However, in the present invention, the second aspect 10
B instead of the means for providing the concave portion 14 in the second side 1
Means for providing a concave portion of another shape such as a triangular cross section on 0B, means for making the surface of the second side surface 10B a rough surface with minute irregularities, and abrupt change of the light path on the second side surface 10B. A means for providing a plurality of possible projections at appropriate intervals, a means for applying a white or other color paint for scattering and reflecting light to the surface of the second side face 10B, or a light reflecting member for scattering and reflecting light For example, means for performing such operations can be employed. Even by such means, when light traveling inside the light guide member 1 reaches the second side surface 10B, a part of the light is reflected in the direction of the first side surface 10A, and
Light can be incident on OA at a small incident angle and transmitted outside.

FIGS. 4 and 5 show the LED light source 3, and FIG. 4 is a sectional view thereof. FIG. 5 is a schematic perspective view thereof.

The LED light source 3 comprises three types of LED chips Dr, Dg, Db for emitting R, G, B light, respectively.
Are packaged together in a resin. More specifically, the LED light source 3 has one first lead 31 and a total of three second leads 32, and the three types of LED chips Dr, Dg, and Db are It is mounted on the internal lead 31a of one lead 31 and is conductive.
These LED chips Dr, Dg, and Db are arranged in a line at minute intervals. On the other hand, each of the three second leads 32 has the LED chips Dr, Dg,
Db is conducted through a wire W such as a gold wire. The first lead 31 and the second lead 32 are embedded in a package resin 33, and an external lead portion of the first lead 31 is a common electrode 31b. In contrast,
The external lead portion of the second lead 32 is an individual electrode 32b. By supplying a drive voltage to the individual electrode 32b or ground connection, three types of LED chips Dr,
Dg and Db can be individually driven. The electrodes 31b and 32b are preferably formed so that the LED light source 3 can be surface-mounted on a desired surface area. For example, the electrodes 31b and 32b are opposed to the lower surface of the package resin 33. Further, the LED light source 3 is one in which a transparent resin 35 such as an epoxy resin is filled in a concave portion 34 having an opening shape on the upper surface of the package resin 33, and the three types of LED chips Dr, Dg, and Db are formed of the transparent resin. Resin 35
Is enclosed in the back. The package resin 33 is
For example, it is a white resin having a high light reflectance.

The LED light source 3 can be manufactured through, for example, the following steps. That is, first
At predetermined positions on a lead frame (not shown) having the leads 31 and the second leads 32, the LED chips Dr, Dg,
After Db is bonded and the work of connecting the wires W is performed, the package resin 33 is molded using a mold. Next, after the transparent resin 35 is filled into the concave portion 34 of the package resin 33, the cutting operation and the forming operation of the lead frame are performed to produce the common electrode 31b and the individual electrode 32b.
Of course, the specific method of manufacturing the LED light source 3 is not limited to such a method. The above LE
The D light source 3 is a resin package of three types of LED chips Dr, Dg, and Db collectively.
By densely mounting the types of LED chips Dr, Dg, and Db, the size of the LED light source 3 as a whole is approximately the same as that of a conventional LED light source, for example.

In the linear light source device A, the LED light source 3 is arranged in the concave portion 16 of the light guide member 1, and as shown in FIG. Are provided so as to substantially coincide with the center portion in the width direction of the light guide member 1. As means for disposing the LED light source 3 in the recess 16, for example, means for directly bonding the LED light source 3 to the light guide member 1,
Means for arranging a substrate on which the substrate is mounted to face the light guide member 1,
Various means can be employed.

Next, the operation of the linear light source device A having the above configuration will be described.

First, when the three types of LED chips Dr, Dg, and Db of the LED light source 3 emit light one by one, the light enters the light guide member 1 from the light incident portion 15 and thereafter. As described in FIG. 6, the light guide member 1
The light exits from various parts of the light exit surface 12 while traveling toward both ends in the longitudinal direction. The LED chips Dr, Dg, Db of the LED light source 3 are provided close to each other,
The light of each color of R, G, and B emitted from these LED light sources 3 is incident on the inside of the light guide member 1 from almost the same place with respect to the light guide member 1. Therefore, R, G,
The light of each color B also exits from the light exit surface 12 after passing through almost the same path, and the amount of light emitted from any of the R, G, and B light and the distribution of the amount of light are different from those of the other light. It is possible to eliminate a significant difference. Further, since the three types of LED chips Dr, Dg, and Db are provided close to each other at the central portion in the width direction of the light guide member 1 or in the vicinity thereof, the three types of LED chips Dr, Dg, and Db are provided. The light emitted from each of the third side face 10C and the fourth side face 10D in the vicinity of the light incident part 15 can be prevented from leaking to the outside as much as possible. This is advantageous in increasing the amount of light. It is assumed that the LED chips Dr, D
Even if light emitted from g and Db passes through the third side surface 10C and the fourth side surface 10D near the light incident portion 15 and leaks to the outside, the amount of light leakage of each color is substantially the same. As a result, the amounts of light emitted from the light emitting surfaces 12 for the respective colors can be made uniform.

Further, the width of the light guide member 1 is one L
Since the width is approximately equal to the width of the ED light source 3, the size of the light guide member 1 can be reduced. In addition, the material cost can be reduced, and the manufacturing cost can be reduced.

FIG. 7 is a sectional view showing an example of an image reading apparatus B having the linear light source device A.

The image reading device B is configured as a so-called close contact type image sensor. The image reading apparatus B mounts a transparent glass plate 49 on the upper surface of the casing 41 so as to cover the opening of the upper surface of the casing 41, so that the surface (upper surface) of the image reading surface 4
It is 2. Below the transparent glass plate 49, a rod lens array 46 and a plurality of light receiving elements 45 for reading the image of the document K conveyed while being in close contact with the image reading surface 42 by the platen roller 43 line by line. Is provided. The plurality of light receiving elements 45
Is a photoelectric conversion element such as a CCD, for example, which is arranged in a line along the longitudinal direction of the reading line on the image reading surface 43 and mounted on the substrate 44. The rod lens array 46 focuses the reflected light from the document K on the plurality of light receiving elements 45.

The linear light source device A is housed inside the casing 41 and is arranged on one side of the rod lens array 46. The light guide member 1 is inclined at an appropriate angle θ such that the light exit surface 12 of the light guide member 1 faces the image reading area of the image reading surface 42.

In the image reading apparatus B having the above-described structure, the R, G, and B lights are emitted from the light emitting surface 12 of the linear light source device A toward the image reading surface 42, thereby forming a color image of the original K. Can be read line by line by the light receiving element 45. As described above, the light exit surface 12
Since the amounts of light of the respective colors R, G, and B emitted from the scanner are uniform, the color tone of the read image does not greatly differ from the color tone of the actual image of the original K, and the quality of the read image is improved. be able to.

In the image reading device B, since the width b1 of the light guide member 1 of the linear light source device A is small,
The inclination angle θ of the light guide member 1 is reduced so that the light exit surface 1
2 can face a predetermined image reading surface 42. Therefore, the apparent width b2 of the light guide member 1 can be reduced, and the overall width dimension b3 of the casing 41 that houses the light guide member 1 therein can also be reduced. As a result, the size of the image reading device B can be reduced. Furthermore, if the inclination angle θ of the light guide member 1 is reduced, light can be irradiated at an angle close to a right angle with respect to the image reading area of the document K, and therefore, the illuminance of the image reading area can be increased. , Would be advantageous.

FIG. 8 shows a linear light source device A according to the present invention.
FIG. 4A is a cross-sectional view illustrating another example of the image reading device Ba including the linear light source device Aa. In the following drawings, the same parts as those in the above embodiment are denoted by the same reference numerals.

The linear light source device Aa includes a first light guide member 1, a second light guide member 2, and an LED light source 3. The first light guide member 1 and the LED light source 3
Is the same as the light guide member 1 and the LED light source 3 of the linear light source device A described in the above embodiment. The second light guide member 2 is formed integrally with or separate from the first light guide member 1. For example, an acrylic transparent resin similar to the first light guide member 1 is molded. The resulting transparent member occupies the main part. The second light guide member 2 includes the first light guide member 2.
A first side surface 20A, a second side surface 20B facing the upper and lower thickness directions, and a slant facing the left and right width directions as a plurality of outer peripheral surfaces extending substantially in the longitudinal direction and having substantially the same overall length as the light guide member 1 of FIG. Planar third side surface 20C, fourth side surface 20D
have. Each of these side surfaces 20A to 20D is a mirror-like plane. The second light guide member 2
Are disposed between the first light guide member 1 and the rod lens array 46 and the transparent glass plate 49.

In the image reading device Ba provided with the linear light source device Aa, when light is emitted upward from the light exit surface 12 of the first light guide member 1, the light is inclined by the second light guide member 2. The light reaches the planar third side surface 20C and is totally reflected in the direction of the fourth side surface 20D. Then, the light that has reached the fourth side surface 20D is reflected by the fourth side surface 20D toward a predetermined image reading area of the document K, and is reflected by the first side surface 20A.
Illuminates the original K through the light. Then, the reflected light from the document K passes through the inside of the second transparent member 2 and then reaches the rod lens array 46, where the light is received by the light receiving element 45.
Is appropriately received.

In the image reading device Ba, unlike the image reading device B described with reference to FIG. 7, the first light guide member 1 does not need to be provided in the casing 41 in an inclined manner. LED on 44A
After mounting the light source 3, the first light source
The light guide member 1 may be arranged in a non-inclined manner, and the work of assembling the LED light source 3 at a predetermined position in association with the first light guide member 1 is significantly facilitated. Further, the light emitted from the first light guide member 1 travels along a predetermined path inside the second light guide member 2 to reach the image reading area of the document K from the first light guide member 1. It is also possible to lengthen the optical distance to. By increasing the optical distance in this way, even if the amount of light emitted from the entire length of the light exit surface 12 of the first light guide member 1 varies in the longitudinal direction, for example, this variation is caused. The second
It is possible to reduce the amount by the light traveling inside the light guide member 2. Therefore, it is also advantageous in achieving uniform illuminance in the longitudinal direction of the reading line in the image reading area of the document K.

As described above, in the present invention, the light exit surface 12 of the light guide member 1 is used instead of using only one light guide member.
May be configured to use another light guide member (second light guide member) for guiding the light emitted from the optical path to a predetermined path and then to a desired image reading area. Of course, the other light guide member is not limited to the second light guide member 2 described above, and a light guide member having a configuration different from that of the second light guide member 2 may be used. Further, the light exit surface 1 of the light guide member 1
The light emitted from 2 may be guided to a desired image reading area using a reflection mirror or the like.

In the image reading device Ba, a predetermined outer surface area of the first light guide member 1 or the second light guide member 2 is covered with the light reflection plates 8A and 8B having high light reflectance. I have. According to such a configuration, it is possible to prevent a large amount of light traveling inside each of the first light guide member 1 and the second light guide member 2 from leaking outside these light guide members. Thus, the efficiency of irradiating light to the image reading area of the document K can be increased. In the present invention, means for covering the outer surface of the light guide member with the light reflecting member can be appropriately employed.

FIG. 9 shows a linear light source device Ab according to the present invention.
It is a front view which shows the other example of. FIG. 10 is a sectional view taken along line X-X in FIG.
It is sectional drawing. FIG. 11 is a schematic perspective view showing two LED light sources used in the linear light source device Ab.

This linear light source device Ab includes a light guide member 1A,
It is configured to include a first LED light source 3A and a second LED light source 3B. The basic configuration of the light guide member 1A is the same as that of the light guide member 1 described above, and a description thereof will be omitted. The first LED light source 3A and the second L
The ED light source 3B is arranged in the concave portion 16 of the light guide member 1 and is arranged in the width direction of the light guide member 1, as shown in FIG. Line CL
Are arranged symmetrically on the left and right.

As is clearly shown in FIG.
The LED light source 3A is, for example, a resin package in which two types of LED chips Dr and Dg that emit R and G light are put together. Specifically, the first LED light source 3
A mounts two types of LED chips Dr and Dg on one first lead 31A, and these LED chips Dr and Dg.
Are connected to two second leads 32A via wires W. Of course, the first lead 31A and a part of the second lead 32A are embedded in the package resin 33A,
The LED chips Dr and Dg and the wires W are made of transparent resin 3
5 is covered. The external lead portion of the first lead 31A is a common electrode, and the external lead portion of the second lead 32A is an individual electrode, so that the two types of LED chips Dr and Dg can be individually driven. It has become.

The first LED light source 3A can be manufactured by the same manufacturing method as the LED light source 3 described with reference to FIGS. In addition, the first L
The ED light source 3A, for example, as shown in FIG.
After mounting two LED chips Dr and Dg on the first lead 31 used for the ED light source 3, these LEs
The D chips Dr and Dg may be connected to two of the three second leads 32 via the wire W. With such a configuration, the first L
When manufacturing the ED light source 3A, the same lead frame as that of the LED light source 3 can be used, and the manufacturing cost can be reduced by using common components.

In FIG. 11, the second LED light source 3
B is obtained by resin-packaging the LED chip Db emitting the light of B. As the second LED light source 3B, one having the same configuration as the conventional LED light source can be used, and a detailed description thereof will be omitted for convenience.

In the linear light source device Ab having the above configuration,
By driving the first LED light source 3A and the second LED light source 3B, light of a total of three colors of R, G, and B can be made incident from the light incident portion 15 of the light guide member 1A. The light can be emitted linearly from the entire length of the light exit surface 12. The two types of LED chips Dr and Dg incorporated in the first LED light source 3A are:
Since the first LED light source 3A and the second LED light source 3B are brought closer to each other, the three types of LED chips Dr, Dg, and Db are also brought closer to each other. be able to. Accordingly, the light of each color of R, G, and B enters the light guide member 1A from almost the same position with respect to the light guide member 1, and as a result, the lights are almost the same in the light guide member 1A. The light travels along the path and exits from the light exit surface 12, and R, G,
The outgoing light amount or light amount distribution of one of the lights B does not greatly differ from the outgoing light amount or light amount distribution of the other light.

The first LED light source 3A and the second LED
Since the light source 3B is arranged symmetrically in the width direction of the light guide member 1A, one of the LED chips Dr, Dg, Db is larger than the other LED chips from the center in the width direction of the light guide member 1A. It is no longer arranged at a biased position. Therefore, it is possible to prevent light emitted from each of the LED chips Dr, Dg, and Db from leaking outside through the third side surface 10C and the fourth side surface 10D near the light incident portion 15 as much as possible. This makes it possible to increase the amount of light emitted from the light emitting surface 12 and to make the amount of light emitted for each color uniform, which is more advantageous.

Further, the width of the light guide member 1 is the first L
Since the size of the ED light source 3A and the size of the second LED light source 3B may be substantially the same, the thickness of the light guide member 1A can be reduced.
The size can be reduced. Further, the material cost can be reduced and the manufacturing cost can be reduced.

In the linear light source device Ab, the first LED light source 3A emits R and G light, and the second LED light source 3 emits B light. It is not limited to this. In the present invention, the first LE
The D light source may be configured to emit R and B light or G and B light, and the second LED light source may be configured to emit light of another color.

In addition, the specific configuration of each part of the linear light source device, the image reading device, and the resin package type LED light source according to the present invention is not limited to the above-described embodiment, and various design changes can be made. The light guide member according to the present invention is:
For example, the present invention is not limited to a configuration in which the LED light source is opposed to the central portion in the longitudinal direction of the second side surface 10B facing the light emitting surface 12, but may be an intermediate region other than the central portion in the longitudinal direction of the second side surface 10B, or a longitudinal end region. The LED light source may face the LED light source. Furthermore, the third side surface 1 of the light guide member
0C, the fourth side face 10D, or the end faces 10E, 10F at both ends in the longitudinal direction.
The light emitted from the LED light source may be made to enter the inside of the light guide member by facing the ED light source. As a light guide member constituting the linear light source device, FIG.
The means using the conventional light guide member described with reference to FIG. 15 is within the technical scope of the present invention as long as the light guide member is used in combination with the resin package type LED light source according to the present invention.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a linear light source device according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III of FIG. 1;

FIG. 4 is an LE used in the linear light source device shown in FIG. 1;
It is sectional drawing which shows D light source.

FIG. 5 is a schematic perspective view of the LED light source shown in FIG.

FIG. 6 is an explanatory diagram showing an operation of the linear light source device shown in FIG.

FIG. 7 is a sectional view showing an example of the image reading apparatus according to the present invention.

FIG. 8 is a sectional view showing another example of the image reading apparatus according to the present invention.

FIG. 9 is a front view showing another example of the linear light source device according to the present invention.

FIG. 10 is a sectional view taken along line XX of FIG. 9;

11 is a schematic perspective view showing a first LED light source and a second LED light source used in the linear light source device shown in FIG.

FIG. 12 is a schematic perspective view showing another example of the first LED light source.

FIG. 13 is a perspective view showing an example of a conventional linear light source device.

FIG. 14 is a front view showing the operation of the linear light source device shown in FIG.

FIG. 15 is a plan view showing the operation of the linear light source device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light guide member 2 2nd light guide member (other light guide members) 3 LED light source 3A 1st LED light source 3B 2nd LED light source 10A 1st side surface (peripheral side surface of a light guide member) 10B 2nd side surface (guide) 10C Third side surface (outer side surface of light guide member) 10C Fourth side surface (outer side surface of light guide member) 12 Light emitting surface 15 Light incident portion A, Aa, Ab Linear light source device B, Ba Image reading device Dr, Dg, Db LED chip

Claims (8)

[Claims] A light source that emits light of each color of R, G, and B;
A light guide member for dispersing light emitted from the light source and entering the inside into a band shape and emitting the light from substantially the entire length of a light exit surface having a predetermined length, Are three types of L that emit light of each color of R, G, and B
A linear light source device, which is a one-package type LED light source in which ED chips are collectively packaged with a resin. 2. The light guide member, wherein a first side surface among a plurality of outer peripheral side surfaces extending in a longitudinal direction thereof is the light exit surface, and any one of an outer surface of the light guide member other than the light exit surface. A partial region of the light guide member is a light incident portion where light is incident from the light source into the light guide member, and light incident into the light guide member from the light incident portion is reflected by the plurality of outer peripheral side surfaces. The one-package LED light source is configured to emit light from the light emitting surface while traveling in the longitudinal direction, and the central portion of the light incident member in the short direction of the light guide member. Claim 1
4. The linear light source device according to 1. 3. A light source for emitting light of each color of R, G, and B;
A light guide member for dispersing light emitted from the light source and entering the inside into a band shape and emitting the light from substantially the entire length of a light exit surface having a predetermined length, Are three types of L that emit light of each color of R, G, and B
Among the ED chips, a first LED light source in which two kinds of LED chips are packaged as a single resin and a second LED in which the remaining one kind of LED chips are individually resin-packaged with the first LED light source A linear light source device characterized by being combined with an LED light source. 4. The light guide member, wherein a first side surface of a plurality of outer peripheral side surfaces extending in the longitudinal direction is the light exit surface, and any one of the outer surfaces of the light guide member other than the light exit surface. A partial region of the light guide member is a light incident portion where light is incident from the light source into the light guide member, and light incident into the light guide member from the light incident portion is reflected by the plurality of outer peripheral side surfaces. The first LED light source and the second LED light source are configured to emit light from the light exit surface while traveling in the longitudinal direction, and the first LED light source and the second LED light source The linear light source device according to claim 3, wherein the linear light source device is arranged symmetrically with respect to a center portion in the short direction. 5. A light guide member further comprising: a light guide member configured to cause light emitted from a light exit surface of the light guide member to travel along a predetermined path so as to linearly irradiate the light to a predetermined position. Item 5. The linear light source device according to any one of Items 1 to 4. 6. A method for irradiating a predetermined image reading surface with light from a light source device and reading reflected light from the image reading object on a reading line of the image reading object arranged opposite to the image reading surface. An image reading device configured to receive light by a plurality of light receiving elements arranged in a line direction, wherein the linear light source device according to any one of claims 1 to 5 is used as the light source device. An image reading device characterized by the above-mentioned. 7. A resin package type LED light source, characterized in that three types of LED chips emitting light of each color of R, G, B are packaged together in a resin. 8. A resin package type LED, wherein two types of LED chips emitting two colors of light of three colors of R, G and B are packaged together in a resin. light source.