JP2003197021A - Planar light source device and image reader device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To save labor and time in an assembling process by reducing the number of products under working and eliminating reversion of a workpiece during a working process. <P>SOLUTION: An LED module 12 is attached to an outer frame 13 by fitting three pins 15 formed in a recess part 16 of the outer frame 13 in holes 17 formed in the LED module 12 corresponding to the pins 15. A transparent light guide plate 11 is fitted from the upper part into the outer frame 13 integrally formed with a bottom lid and the transparent light guide plate 11 is fixed by a hook 21 provided in the outer frame 13. Then, the transparent light guide plate 11 is pushed toward the LED module 12 by a push spring 18 so as to prevent a clearance from being formed between the transparent light guide plate 11 and the LED module 12. This device has such a structure as capable of working from one direction like that the transparent light guide plate 11 is fitted to the outer frame 13 from the upper part and a dispersion sheet 14 is stuck to the outer edge surface of the outer frame from the upper part. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide type planar light source device and an image reading apparatus using this planar light source device, and more particularly to a planar light source device capable of labor saving and time saving in an assembly process. Also, the present invention relates to an image reading device using the planar light source device.

[0002]

2. Description of the Related Art In recent years, a planar light source device using a light emitting diode (LED) and a light guide plate has been commercialized. This planar light source device is a CIS (Contact Image).
It is used as a transmitted light unit of a Sensor type scanner. In this planar light source device, light emitted from an LED is incident on a light guide plate, scattered by a diffusion pattern provided on the bottom surface of the light guide plate, and constitutes a uniform planar light source device through a diffusion sheet.

FIG. 12 is an exploded perspective view showing a conventional planar light source device. The planar light source device shown in FIG. 12 includes a transparent light guide plate 51, an LED module 52, an outer frame 53, a diffusion sheet 54, and a bottom cover 55.

The LED module 52 is attached to the inner surfaces of the outer frame 53 which face each other in the direction orthogonal to the longitudinal direction.

Notches for taking out the leads of the LED module 52 are provided on both end surfaces of the bottom lid 55 in a direction orthogonal to the longitudinal direction.

On the lower surface of the transparent light guide plate 51, the LED
A light-scattering pattern for scattering light that has entered the transparent light guide plate 51 from the module 52 is formed.

This conventional planar light source device is assembled as follows. First, the LED module 52 is attached to the inner surface of the outer frame 53 with an adhesive. Next, the LED
The transparent light guide plate 51 is fitted into the outer frame 53 to which the module 52 is adhered from below, and the transparent light guide plate 5 is attached by the bottom cover 55.
1, and finally, the diffusion sheet 54 is attached to the upper edge surface of the outer frame 53.

[0008]

As described above, since the conventional planar light source device has a structure in which the LED module is attached to the inner surface of the outer frame with an adhesive, the adhesive is dried and the LED module is removed from the outside. There is a problem that it takes a long time to completely adhere to the inner surface of the frame and the number of products in the process of waiting for the adhesive to dry increases.

Furthermore, since the transparent light guide plate and the bottom cover are fitted into the outer frame from below and the diffusion sheet is attached from above, the outer frame must be processed from both the upper and lower sides. Among them, it is necessary to invert the work (processed product), which is troublesome and difficult to automate.

The present invention has been made by paying attention to such a conventional problem, and an object thereof is to reduce the number of products in the process of machining and to invert the work (processed product) during the machining process. An object of the present invention is to provide a planar light source device which can eliminate the labor and time saving of the assembly process and an image reading device using the planar light source device.

[0011]

According to the present invention, there is provided a flat transparent light guide plate and at least one of which light is incident on the transparent light guide plate.
Two light sources, the transparent light guide plate and the light source are housed,
A planar light source device comprising an outer frame integrally formed with a bottom lid and a diffusion sheet arranged on the upper surface of the transparent light guide plate, wherein the light source includes at least one pin formed in the outer frame. , The transparent light guide plate is attached to the outer frame by fitting with a hole formed in the light source corresponding to the pin, and the transparent light guide plate is arranged on the outer frame so that the light source is arranged on an end face of the transparent light guide plate. It is characterized by being fitted.

The present invention also includes a flat transparent light guide plate,
A planar light source including at least one light source that allows light to enter the transparent light guide plate, an outer frame that houses the transparent light guide plate and the light source, a bottom cover, and a diffusion sheet that is disposed on an upper surface of the transparent light guide plate. In the device, the bottom lid is fixed to the outer frame by fitting a protrusion-shaped locking portion provided on an end surface of the bottom lid and a recess provided in a lower portion of an inner side surface of the outer frame. The light source is attached to the outer frame by fitting at least one pin formed in the outer frame and a hole formed in the light source corresponding to the pin, and the transparent light guide plate is transparent. The light source is fitted to the outer frame so that the light source is disposed on the end surface of the light guide plate.

The pin is formed in a concave portion formed in the outer frame, and the light source is formed in the concave portion of the outer frame by fitting the pin and a hole formed in the light source corresponding to the pin. It is desirable to be attached.

Further, it is preferable that the outer frame is provided with a spring for pressing the transparent light guide plate against the light source.

Further, the diffusion sheet is attached to a lower surface of a reinforcing frame provided around the diffusion sheet, and the outer frame is a part of an upper edge surface of the diffusion sheet, and only a portion for accommodating the reinforcing frame of the diffusion sheet. The reinforcing frame has a notch, and the reinforcing frame is provided on the outer frame by fitting a protrusion-shaped locking portion provided on an end surface of the reinforcing frame and a recess provided on the inner side surface of the notch of the outer frame. It is desirable to be stored.

Alternatively, the outer frame has a part of the upper edge surface,
The diffusion sheet has a notch only in a portion for accommodating the diffusion sheet, and the diffusion sheet has a protrusion-shaped engaging portion provided on an end surface of the diffusion sheet, and a recess provided on an inner side surface of the notch of the outer frame. The planar light source device according to any one of claims 1 to 4, wherein the planar light source device is housed in the outer frame by fitting.

Further, it is preferable that the transparent light guide plate is fixed to the outer frame by a hook which is a protrusion-like engaging portion provided on the outer frame or the transparent light guide plate and has a contact surface at a lower end. .

It is preferable that the hooks are formed on one of the opposing inner side surfaces of the outer frame in a state of being separated from each other, and on both sides of the mounting position of the light source.

Alternatively, the hook is formed on one of the facing inner side surfaces of the outer frame in a positional relationship that is point-symmetrical with respect to the center of the outer frame, and further, the width of the other facing inner side surface of the outer frame. It is desirable to be formed in the central portion in the direction.

Alternatively, it is desirable that the hooks are formed on one of the opposing inner side surfaces of the outer frame in a state of being separated from each other.

Further, it is preferable that the hook is provided at the uppermost portion of the inner side surface of the outer frame, and the height of the transparent light guide plate is up to the contact surface of the hook.

Alternatively, the hook is provided at the uppermost portion of the inner side surface of the outer frame, and the transparent light guide plate is formed so as to have a step surface that abuts against the abutment surface of the hook from below. It is desirable that the upper surface of the outer frame and the outer edge surface of the outer frame be flush with each other.

Alternatively, the hook is provided at an intermediate portion in the height direction of the inner side surface of the outer frame, and the transparent light guide plate is formed so as to have a stepped surface that abuts the abutment surface of the hook from below. It is preferable that the upper surface of the transparent light guide plate and the outer edge surface of the outer frame are flush with each other.

Alternatively, it is preferable that the hook is provided at an intermediate portion in the height direction of the transparent light guide plate, and a concave portion for fitting with the hook is provided at an intermediate portion in the height direction of the inner side surface of the outer frame.

Further, in the image reading apparatus of the present invention, it is desirable to use the above-mentioned planar light source device as an illumination light source for a transparent original.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first planar light source device according to the present invention.
FIG. 3 is an exploded perspective view showing the embodiment of FIG. The planar light source device of the present invention includes a planar transparent light guide plate 11 and a transparent light guide plate 11.
The LED module 12 which is a light source for injecting light to the bottom, the outer frame 13 integrally formed with the bottom cover, and the diffusion sheet 14 arranged on the upper surface of the transparent light guide plate 11.

The outer frame 13 is formed integrally with the bottom cover,
The outer frame 13 is made of, for example, polycarbonate resin or the like, which has good processing accuracy and high mechanical strength. A recess 16 for accommodating the LED module 12 is formed on one of the opposing inner side surfaces of the outer frame 13 in a direction orthogonal to the longitudinal direction, and the inner side surface of the recess 16 holds the LED module 12 therein. Three pins 15 for positioning are provided. The pin 15 is formed integrally with or separately from the outer frame 13. Further, this pin may be a split pin 15a as shown in FIG. FIG. 2 is a perspective view of the outer frame when the pin is replaced with a split pin and an enlarged view of the split pin 15a.

Two of the three pins are formed horizontally with respect to the upper surface of the outer frame 13, and one of the three pins is a line with respect to the center line of the recess 16 in the height direction. It is formed at a position that is not symmetrical. This is to enable the LED module 12 to be installed without mistake when mounting the LED module 12. Also, here, the number of pins is three,
The LED module 12 cannot rotate in this recess 16,
Since the positioning is possible, the number of pins may be one or two.

Further, the LED module 12 is provided on the bottom lid portion of the outer frame 13 which is exposed by forming the recess 16.
Lead-out hole 20 for taking out lead 19 of
Is provided.

A push spring 18 having a leaf spring-like structure is formed on the other of the opposing inner side surfaces in the direction orthogonal to the longitudinal direction of the outer frame 13. The push spring 18 is formed integrally with the outer frame 13.

The push spring 18 connects the transparent light guide plate 11 to the outer frame 1.
When housed in 3, the transparent light guide plate 11 is pressed against the LED module 12 side to prevent a gap from being left between the transparent light guide plate 11 and the LED module 12. This push spring 18
May be pressed against the back surface of the LED module 12, and may be near the pin on the LED module 12 side.

Further, hooks 21 are provided on the inner surface of the outer frame 13 on both sides of the recess 16 and the push spring 18 as projecting locking portions.

The LED module 12 is composed of red (R), green (G), and blue (B) LED chips, and LE
The D module 12 is formed with a hole 17 for fitting with the pin 15. When the pin 15 is fitted into the hole 17, the LED module 12 is attached to the outer frame 1
3 is attached and positioned without adhesive.

On the lower surface of the transparent light guide plate 11, the LED
A light-scattering pattern for scattering light that has entered the transparent light guide plate 11 through the light emitting window 30 of the module 12 is formed. This light-scattering body pattern is formed by screen printing with a specific pattern using, for example, a light-reflecting white ink. A transparent material such as acrylic or glass is used for the transparent light guide plate 11.

When assembling, first, the LED module 12 is inserted into the hole 17 formed in the LED module 12 so that the pin 15 also serves as a positioning member.
3 is mounted and positioned.

Next, in the outer frame 13 integrally formed with the bottom lid,
The transparent light guide plate 11 is fitted from the upper part, and the transparent light guide plate 11 is fixed by the hooks 21 provided on the upper inner side surface of the outer frame 13. At this time, the transparent light guide plate 11 is pressed against the LED module 12 side by the force of the pressing spring 18 provided on the outer frame 13, and the LED module 12 is pressed against the outer frame 13 by this force. Finally, the diffusion sheet 14 is attached from the top to the outer edge surface of the outer frame.

In the planar light source device having such a structure,
From the light emitting window 30 of the LED module 12 to the transparent light guide plate 11
The light incident on the light guides inside the transparent light guide plate 11, is scattered by the light scattering pattern, reaches the diffusion sheet 14 attached to the upper surface of the transparent light guide plate 11, and is diffused by the diffusion sheet 14 so that the light has a uniform illuminance. Emit with distribution.

In the above-described embodiment, the case of the one-light type having one LED module as the light source has been described, but in the case of the two-light type, as shown in FIG. A recess 16 for accommodating the LED module 12 is formed on both of the inner surfaces facing each other in the direction orthogonal to the longitudinal direction, and a pin 15b for positioning the LED module 12 is formed on the inner surface of the recess 16. And LED
LE through the pin 15b in the hole 17 of the module 12
The D module 12 is arranged.

When assembling, first, the LED module 12 is attached to the outer frame 13 through the pin 15b which also serves as a positioning through the hole 17 formed in the LED module 12. At this stage, the LED module 12 is temporarily fixed.

Next, the transparent light guide plate 11 is fitted from above while keeping the LED module 12 from falling down. Therefore, the pin 15b is a split pin as shown in the enlarged view of FIG. 3, and the thicker tip is more suitable for temporarily fixing and assembling the LED module 12. When the transparent light guide plate 11 is pushed into the outer frame 13, the LED module 12 is also completely fixed to the outer frame 13.

Although only one push spring is provided in FIG. 1, a method of providing a plurality of push springs in a place where there is no LED module is also effective because the fixation becomes more reliable. Further, in FIG. 3, although the push spring is not provided, L
The method of providing one or more push springs in the place where there is no ED module is also effective because the fixation becomes more firm.

The split pin 15 shown in FIGS. 2 and 3 is also used.
As shown in FIG. 4, it is more preferable that a and 15b have a thick tip, a thin portion near the center, and a thicker end. The LED module tends to be pushed back toward the tip end due to the thick base of the split pin, but in the one-lamp type, the push spring is applied from the opposite side, and in the two-lamp type, the LED module at the other end is used, and Will have a narrower space between each other and will be more firmly fixed.

FIG. 5 is a sectional view when the LED module and the transparent light guide plate are brought into close contact with each other. As shown in FIG. 5, the LED chip 36 is protected by a transparent resin 39, and the transparent resin 39 is formed so as to fit in a recess 38 provided in the printed board 37. By doing so, the LED module 12 and the transparent light guide plate 11 can be brought into close contact with each other, so that the light emitted from the LED chip 36 can be prevented from leaking to the outside. If the transparent resin 39 is provided so as to protrude from the recess 38 provided in the printed board 37, the LED module 12 and the transparent light guide plate 11 are provided.
Cannot be brought into close contact with each other, and light from the LED chip 36 leaks from a gap formed between the two, which is not preferable.

Further, in the above-described embodiment, the outer frame 13
A recess 16 for housing the LED module 12 was formed on the inner side surface of the, and a pin 15 for positioning the LED module 12 was formed on the inner side surface of the recess 16, but with respect to the longitudinal direction of the transparent light guide plate 11. When a recess for accommodating the LED module 12 is formed on the end surface in the direction orthogonal to each other, the pin 15 may be formed on the inner side surface of the outer frame 13 without forming the recess 16 on the outer frame 13. good.

As described above, in this planar light source device, the transparent light guide plate 11 is fitted into the outer frame 13 from the upper portion, and the diffusion sheet 14 is attached from the upper portion to the outer edge surface of the outer frame. Since the structure allows machining from one direction, there is no need to invert the work (processed product) during the machining process, which saves labor and facilitates automation of the process.

Next, an example of changing the position of the hook for fixing the transparent light guide plate to the outer frame will be described. FIG. 6 is a plan view of the outer frame showing an example of the formation position of the hook in the plane direction.

FIG. 6 (a) is similar to the position of the hooks shown in FIGS. 1 and 3, and a total of four hooks 21 are provided on the inner surfaces facing each other in the direction orthogonal to the longitudinal direction of the outer frame 13.
The case where a is formed is shown. The hook 21a is LE
It is formed on both sides of the mounting position of the D module.

Further, in FIG. 6B, a total of four hooks 21b are provided on the opposing inner side surfaces of the outer frame 13 in the direction orthogonal to the longitudinal direction and the opposing inner side surfaces of the outer frame 13 in the longitudinal direction.
It shows the case of forming. The hooks 21b formed in the direction orthogonal to the longitudinal direction of the outer frame 13 have a positional relationship that is point-symmetrical with respect to the center of the outer frame 13, and the hooks 21b formed in the longitudinal direction of the outer frame 13 are provided. Is located in the widthwise central portion of the inner surface in the longitudinal direction.

Further, FIG. 6C shows a case where a total of four hooks 21c are formed on the inner side surfaces of the outer frame 13 which are opposed to each other in the longitudinal direction and are separated from each other.

FIG. 7 is a partial sectional view showing an example of the formation position of the hook in the height direction.

In FIG. 7 (a), a hook 21d, which is a protruding locking portion having a contact surface at the lower end, is provided at the uppermost portion of the inner side surface of the outer frame 13a, and the height of the transparent light guide plate 11a is hooked. 21
The case where the transparent light guide plate 11a contacts the contact surface from below and is fixed to the outer frame 13a is shown up to the contact surface of d.

Further, in FIG. 7B, a hook 21e is provided at the uppermost portion of the inner side surface of the outer frame 13b, and the transparent light guide plate 1 has a stepped surface that abuts against the abutment surface of the hook 21e from below.
1b is formed, and the upper surface of the transparent light guide plate 11b and the outer frame 13b are formed.
It shows a case where the outer edge surfaces of are made to be on the same plane.

Further, in FIG. 7 (c), a hook 21f is provided on the inner side surface of the outer frame 13c at the middle portion in the height direction.
The case where the transparent light guide plate 11c is formed so that the contact surface of f has a stepped surface that abuts from the lower side, and the upper surface of the transparent light guide plate 11c and the outer edge surface of the outer frame 13c are flush with each other is shown. ing.

Further, FIG. 7D shows a transparent light guide plate 11d.
21g is provided in the middle part in the height direction of the outer frame 13d.
It shows a case where a concave portion that fits with the hook 21g is provided in the middle portion of the inner side surface in the height direction.

Next, a second embodiment of the present invention will be described. FIG. 8 is an exploded perspective view showing a second embodiment of the planar light source device according to the present invention.

In FIG. 8, the diffusion sheet 14a is attached to the lower surface of the acrylic reinforcing frame 22 provided around the diffusion sheet 14a. On a part of the upper edge surface of the outer frame 13e,
Only the portion of the diffusion sheet 14a that houses the reinforcing frame 22 has a cutout. Hooks 23, which are projecting locking portions, are provided on both end surfaces of the reinforcing frame 22 in a direction orthogonal to the longitudinal direction, and the hooks 23 are provided on the inner surface of the cutout of the outer frame 13e. The reinforcing frame 22 is housed in the outer frame 13e by fitting with the recess 24. Others are the same as those in the first embodiment, and thus the description thereof will be omitted.

It should be noted that the hook 23, which is a protrusion-like locking portion,
May be provided on both end surfaces of the reinforcing frame 22 in the longitudinal direction.

Next, a third embodiment of the present invention will be described. FIG. 9 is an exploded perspective view showing a third embodiment of the planar light source device according to the present invention.

In FIG. 9, a part of the upper edge surface of the outer frame 13f has a notch only in a portion for accommodating the acrylic diffusion sheet 14b. On both end surfaces of the diffusion sheet 14b in the direction orthogonal to the longitudinal direction, the hooks 2 that are projecting locking portions are provided.
5, the diffusion sheet 14b is housed in the outer frame 13f by fitting with the recesses 26 provided on the inner side surface of the cutout of the outer frame 13f with the hooks 25.

The hook 25, which is a protrusion-like locking portion,
May be provided on both end surfaces in the longitudinal direction of the diffusion sheet 14b.

The acrylic surface of the area of the diffusion sheet 14b which is in contact with the transparent light guide plate 11 is roughened, and is roughened by, for example, sandblasting, thereby functioning as a diffusion sheet. The thickness of the diffusion sheet 14b is the same as that of the transparent light guide plate 1.
In the area in contact with 1, the outer frame 13 is 0.5 mm.
The peripheral part (including the hook) in contact with f is thickened to 1.0 mm in order to maintain strength. Others are the same as those in the first embodiment, and thus the description thereof will be omitted.

In the above-described first embodiment, since the diffusion sheet is attached to the outer edge surface of the outer frame, work steps such as sheet alignment and sheet cutting are required. Since the third embodiment has a structure in which the diffusion sheet is fitted in the outer frame, such a work process can be omitted.

Next, a fourth embodiment of the present invention will be described. FIG. 10 shows a fourth planar light source device according to the present invention.
FIG. 3 is an exploded perspective view showing the embodiment of FIG.

In the surface light source device shown in FIG. 10, the outer frame 13
g is not integrally formed with the bottom cover, and the bottom cover 2 is attached to the outer frame 13g.
It has a structure in which 7 is fitted.

A concave portion 28 is provided in the lower portion of the opposing inner side surfaces in the direction orthogonal to the longitudinal direction of the outer frame 13g. Hooks 29, which are projecting locking portions, are provided on both end surfaces of the bottom lid 27 in a direction orthogonal to the longitudinal direction, and the recesses 28 provided on the inner side surface of the outer frame 13g are provided by the hooks 29. And the bottom lid 27 is fixed to the outer frame 13g. In addition, the recess 28 is provided in the lower portion of the inner side surfaces of the outer frame 13g which face each other in the longitudinal direction, and the hook 29 which is a protrusion-shaped locking portion.
May be provided on both end surfaces of the bottom lid 27 in the longitudinal direction. Others are the same as those in the first embodiment, and thus the description thereof will be omitted.

In the above-mentioned embodiment, the case where the number of the LED modules serving as the light source is one and two has been described. However, the present invention is not limited to the shape of the light scattering pattern formed on the lower surface of the transparent light guide plate. Since a substantially uniform brightness distribution can be realized, the number of LED modules is not limited to one and two, and may be arranged on all side surfaces of the light guide body, and the LED modules are not limited to the central portion of the side surface of the light guide plate. It may be placed anywhere on the side surface. That is, the present invention is
It can be applied when at least one light source is provided.

Next, an image reading apparatus using the planar light source device of the present invention will be described. FIG. 11 is a diagram showing an example of a contact image sensor type image reading apparatus capable of reading a transparent original. The planar light source device of the present invention is used as an illumination light source for illuminating a transparent original.

In the image reading apparatus shown in FIG. 11, the upper surface of the case body 31 is constituted by the original plate glass 32, and the contact type image sensor unit 33 is provided in the case body 31. A paper document or a transparent document 34 is placed on the platen glass 32. The contact image sensor unit 33 has a built-in linear light source necessary for reading a paper original, but is turned off when reading the transparent original 34.

Above the platen glass 32, there is provided a surface light source device 35 according to the present invention.
Is built in a document pressing cover (not shown) or is replaced with the document pressing cover when reading the transparent document 34.

When reading the transparent original 34, the contact image sensor unit 33 is reciprocally driven in a fixed direction,
The light emitted from the planar illumination device 35 is reflected by the platen glass 32.
Through the rod lens array in the contact image sensor unit 33, and the line sensor detects the transparent original 34 for scanning.

Although the contact type image sensor type image reading apparatus has been described with reference to FIG. 11, the present invention is not limited to the contact type image sensor type image reading apparatus, and another reduction optical system is used. It goes without saying that it can also be used for a CCD type image reading device and the like.

[0073]

As described above, the present invention provides an LED
When the module is mounted on the transparent light guide plate, there is no adhesive bonding step and there is no adhesive curing waiting time, so the processing time can be shortened and the number of products in the process can be reduced.

Further, since the parts are fitted into the outer frame serving as the base from one direction, there is no need to reverse the work (work product) during the working process, and the labor of the work can be saved. It is easy to automate the process.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a planar light source device according to the present invention.

FIG. 2 is a perspective view of an outer frame when a pin is replaced with a split pin and an enlarged view of the split pin.

FIG. 3 is an exploded perspective view when two LED modules are provided.

FIG. 4 is a diagram showing another example of the split pin.

FIG. 5 is a cross-sectional view when an LED module and a transparent light guide plate are brought into close contact with each other.

FIG. 6 is a plan view of an outer frame showing an example of a formation position of a hook in a plane direction.

FIG. 7 is a partial cross-sectional view showing an example of the formation position of the hook in the height direction.

FIG. 8 is an exploded perspective view showing a second embodiment of the planar light source device according to the present invention.

FIG. 9 is an exploded perspective view showing a third embodiment of the planar light source device according to the present invention.

FIG. 10 is an exploded perspective view showing a fourth embodiment of the planar light source device according to the present invention.

FIG. 11 is a diagram showing an example of an image reading apparatus using the planar light source device according to the present invention.

FIG. 12 is an exploded perspective view showing a conventional planar light source device.

[Explanation of symbols]

11, 11a to 11d, 51 transparent light guide plate 12,52 LED module 13, 13a to 13g, 53 outer frame 14,14a, 14b, 54 Diffusion sheet 15,15a, 15b pin 16, 24, 26, 28, 38 Recess 17 holes 18 Push spring 19 lead 20 Hole for taking out lead 21,21a-21g, 23,25,29 hook 22 Reinforcement frame 27,55 Bottom lid 30 luminous window 31 Case body 32 Platen glass 33 Contact image sensor unit 34 Transparent manuscript 35 planar light source device 36 LED chips 37 Printed circuit board 39 Transparent resin

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 1/04 101 H04N 1/04 101 // F21Y 101: 02 F21Y 101: 02 F term (reference) 2H109 AA03 AA13 AA26 AA32 AA67 AA72 DA12 5C051 AA01 BA02 DB01 DB22 DB29 DB31 DC05 DC07 5C072 AA01 BA02 CA05 CA07 CA08 CA09 DA02 DA21 DA30 EA04 QA11

Claims (15)

[Claims] 1. A flat transparent light guide plate, at least one light source for allowing light to enter the transparent light guide plate, and an outer frame in which the transparent light guide plate and the light source are housed and in which a bottom lid is integrally molded. A planar light source device comprising: a diffusion sheet disposed on an upper surface of the transparent light guide plate, wherein the light source is formed on the light source corresponding to at least one pin formed on the outer frame. The planar light source device is attached to the outer frame by fitting with the formed hole, and the transparent light guide plate is fitted into the outer frame such that the light source is arranged on an end surface of the transparent light guide plate. . 2. A flat transparent light guide plate, at least one light source for making light incident on the transparent light guide plate, an outer frame for housing the transparent light guide plate and the light source, a bottom cover, and the transparent light guide plate. A planar light source device comprising: a diffusion sheet disposed on an upper surface, wherein the bottom lid is provided on a lower portion of an inner side surface of the outer frame, and a projecting locking portion provided on an end surface of the bottom lid. Is fixed to the outer frame by fitting with a concave portion, and the light source is configured by fitting at least one pin formed in the outer frame and a hole formed in the light source in correspondence with the pin. A planar light source device mounted on an outer frame, wherein the transparent light guide plate is fitted into the outer frame such that the light source is disposed on an end surface of the transparent light guide plate. 3. The pin is formed in a recess formed in the outer frame, and the light source of the outer frame is formed by fitting the pin and a hole formed in the light source corresponding to the pin. The planar light source device according to claim 1 or 2, which is attached to the recess. 4. The planar light source device according to claim 1, wherein the outer frame is provided with a spring for pressing the transparent light guide plate against the light source. 5. The diffusion sheet is attached to a lower surface of a reinforcing frame provided around the diffusion sheet, and the outer frame is provided only on a portion of an upper edge surface of the diffusion sheet where the reinforcing frame is accommodated. The reinforcing frame has a notch, and the reinforcing frame is provided on the outer frame by fitting a protrusion-shaped locking portion provided on an end surface of the reinforcing frame and a recess provided on the inner side surface of the notch of the outer frame. The planar light source device according to claim 1, wherein the planar light source device is housed. 6. The outer frame has a notch only in a portion of an upper edge surface for accommodating the diffusion sheet, and the diffusion sheet is a protrusion-like engagement provided on an end surface of the diffusion sheet. The planar light source device according to claim 1, wherein the planar light source device is housed in the outer frame by fitting a portion and a recess provided on the inner surface of the cutout of the outer frame. 7. The transparent light guide plate is fixed to the outer frame by a hook provided on the outer frame or the transparent light guide plate, the hook being a protrusion-like locking portion having a contact surface at a lower end. The planar light source device according to claim 1. 8. The hook according to claim 7, wherein the hooks are formed on one of the opposing inner side surfaces of the outer frame in a state of being separated from each other, and formed on both sides of a mounting position of the light source. Planar light source device. 9. The hook is formed on one of the opposing inner side surfaces of the outer frame in a positional relationship that is point-symmetrical with respect to the center of the outer frame, and the width of the other opposing inner side surface of the outer frame. The planar light source device according to claim 7, wherein the planar light source device is formed at a central portion in the direction. 10. The planar light source device according to claim 7, wherein the hooks are formed on one of the opposing inner side surfaces of the outer frame in a state of being separated from each other. 11. The hook according to claim 7, wherein the hook is provided at the uppermost portion of the inner side surface of the outer frame, and the height of the transparent light guide plate is up to the contact surface of the hook. The planar light source device described. 12. The transparent light guide plate, wherein the hook is provided at the uppermost portion of the inner side surface of the outer frame, and the transparent light guide plate is formed so as to have a step surface that abuts against the abutment surface of the hook from below. The planar light source device according to any one of claims 7 to 10, wherein an upper surface of the outer frame and an outer edge surface of the outer frame are flush with each other. 13. The transparent light guide plate is formed so that the hook is provided at an intermediate portion of an inner side surface of the outer frame in a height direction, and the contact surface of the hook has a step surface abutting from below. ,
The planar light source device according to claim 7, wherein an upper surface of the transparent light guide plate and an outer edge surface of the outer frame are flush with each other. 14. The hook is provided at an intermediate portion in the height direction of the transparent light guide plate, and a recess for fitting with the hook is provided at an intermediate portion in the height direction of an inner side surface of the outer frame. The planar light source device according to claim 7. 15. An image reading device using the planar light source device according to claim 1 as an illumination light source for a transparent original.