JPH11266340A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the entire size of the image reader small by properly positioning components of a lens array and a light guide member in a case and assembling them so as not to make them voluminous. SOLUTION: The reader is provided with a case 2 which contains a light source, a light guide member 1 that guides a light from the light source so as to be emitted to each position of a linear image read area P, a lens array 6 extended in a main scanning direction that converges reflected lights from the image read area P and forms an image, a plurality of photodetectors 40 that receive the light converged by the lens array 6 and apply photoelectric conversion to the light, and a container section 21 that contains the lens array 6 and the light guide member 1. At lest one-side faces 10E, 10E, 60a, 60b of the lens array 6 and the light guide member 1 in a subscanning directions respectively are in contact opposite to each other and the side faces 60a, 60b of the lens array 6 in contact with the light guide member 1 are supported by the light guide member 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus which is configured as a so-called contact type image sensor or flat bed type image sensor and is used to read a desired document image.

[0002]

2. Description of the Related Art The applicant of the present invention has previously proposed an image reading apparatus of this type having a structure shown in FIG. 13 (Japanese Patent Application No. 8-333583). This image reading apparatus reads a plurality of light sources 5e such as LEDs that emit light of each color of R, G, and B (red, green, and blue), and reads light emitted from each of the plurality of light sources 5e into a linear image. The light guide member 1e leading to the region Pe, the image reading region Pe
A lens array 6e for converging light reflected from the surface of the document Ke placed on the lens array to form an image, a plurality of light receiving elements 40e for receiving the light converged by the lens array 6e and performing photoelectric conversion, and And a circuit board 3e on which the plurality of light receiving elements 40e are mounted.
Each of the above components is assembled to the housing 2e.

The light guide member 1e is provided with a transparent member having a plurality of side surfaces extending in the main scanning direction, and as shown in FIG. A V-shaped recess 90 is formed, and the light source 5e is disposed at a position facing the recess 90 with the light guide member 1e interposed therebetween. Each of the plurality of side surfaces of the light guide member 1e is formed in a mirror-like shape, but a plurality of concave grooves 93 are formed at appropriate intervals on a second side surface 92 facing the first side surface 91 serving as a light emitting surface. Is provided.

As shown in FIG. 15, in the light guide member 1e, when light emitted from the light source 5e enters the light guide member 1e and reaches the inclined surface 90a of the concave portion 90, the light is transmitted to the light guide member 1e. The light is reflected toward both ends in the longitudinal direction of the member 1e, and thereafter reaches the both ends in the longitudinal direction of the light guide member 1e while repeating total reflection by a plurality of side surfaces of the light guide member 1e. At that time, the light that has reached each of the grooves 93 of the second side surface 92 is reflected so that its traveling direction can be rapidly changed,
Part of the light enters the first side surface 91 at an incident angle smaller than the critical angle for total reflection. Then, the light passes through the first side surface 91 as it is and is emitted to the outside,
The light is irradiated onto the image reading area Pe.

In the above-described image reading apparatus, although a so-called point light source 5e is used as a light source for illuminating the original, the light emitted from the light source 5e is appropriately applied to various parts of the linear image reading area Pe. Can be irradiated. Therefore, there is obtained an advantage that the required number of light sources can be reduced and the component cost and running cost can be reduced.

[0006]

However, the above image reading apparatus has the following disadvantages.

[0007] That is, the above-mentioned image reading apparatus has the structure shown in FIG.
As shown in FIG. 3, the lens array 6e is fitted and held in the concave portion 94 provided in the housing 2e. On the other hand, the light guide member 1e is accommodated in a concave portion 95 provided separately from the concave portion 94, and is supported using a dedicated support member (not shown). For this reason, in the image reading apparatus, the lens array 6e and the light guide member 1e are formed by the wall 96 that partitions the two concave portions 94 and 95.
Are separated from each other, and the lens array 6e and the light guide member 1e are bulky in the sub-scanning direction. As a result, in the above-described image reading device, a certain limit has been generated in reducing the width of the housing 2e that houses the lens array 6e and the light guide member 1e, and reducing the size of the entire image reading device.

The present invention has been devised in view of such circumstances, and appropriately positions and assembles these components in a housing so that the lens array and the light guide member do not become bulky with each other. It is an object of the present invention to make it possible to reduce the size of the entire image reading apparatus.

[0009]

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

That is, the present invention provides a light source and a plurality of light emitted from the light source and incident inside the light source extending in the main scanning direction such that the light emitted from the light source is applied to a linear image reading area. A light guide member for emitting the light from a fixed length region of the first side surface while advancing the light in the main scanning direction by reflecting the light from the side surface of the plurality of side surfaces; and converging the light reflected from the image reading region. A lens array extending in the main scanning direction for forming an image by performing the image formation, a plurality of light receiving elements for receiving light converged by the lens array and performing photoelectric conversion, the lens array and the light guide member, A housing having an accommodating portion accommodated therein, wherein at least one side face of each of the lens array and the light guide member that faces in the sub-scanning direction. There face contact with each other, and the side in contact with the light guide member of said lens array is characterized in that it is supported by the light guide member.

In the present invention, the lens array is directly supported by the light guide member because at least one side of the lens array and the light guide member facing each other in the sub-scanning direction are in opposition to each other. It has become. For this reason, in the present invention, unlike the above-described image reading device in which the lens array and the light guide member are individually supported and arranged so as to be separated from each other,
The lens array and the light guide member can be arranged in the housing so as not to be bulky in the sub-scanning direction. On the other hand, since the lens array is supported by the light guide member, positioning and holding of the lens array can be appropriately performed. As a result, in the present invention, there is obtained an excellent effect that the size of the housing can be reduced and the entire image reading apparatus can be reduced in size without causing any inconvenience in positioning and holding of the lens array. Of course, in the present invention, similarly to the above-described image reading apparatus, while the light emitted from the light source travels in the main scanning direction, the linear image reading area extends from the fixed length area on the first side surface of the light guide member. Since light can be applied to various places, a so-called point light source can be used as the light source, and the number of the light sources can be reduced.

In a preferred embodiment of the present invention, the light guide member includes a first light guide portion extending in a longitudinal direction of the light guide member and two second light guide portions connected to the first light guide portion. And a concave groove portion is formed between the two second light guide portions, and the lens array is fitted in the concave groove portion so that both of the lens array in the width direction are provided. The outer side surface may be configured to be supported by the light guide member.

According to such a configuration, since the lens array is fitted in the concave groove formed in the light guide member, both outer surfaces in the width direction of the lens array are supported by the light guide member. Therefore, the lens array can be reliably supported and positioned and held by the light guide member. Therefore, it is possible to reduce the number of components for positioning and holding the lens array, or to eliminate the components, thereby simplifying the entire configuration. If the lens array is fitted into the concave groove of the light guide member, the lens array and the light guide member overlap each other in the sub-scanning direction. Therefore, as compared with a case where the lens array is arranged to protrude to the side of the light guide member, the light guide member and the lens array can be arranged in a more compact state, and the image reading apparatus can be further improved. Can be reduced in size.

In another preferred embodiment of the present invention,
The first light guide of the light guide member is disposed between the image reading area and the lens array, and a side of the first light guide that faces the image reading area is the first side. And the light guide member is configured such that light emitted from the light source and entering the light guide member from a longitudinal end of the light guide member enters the two second light guide portions and the first light guide member.
It is possible to adopt a configuration in which light is emitted from substantially the entire length area of the first side surface while traveling inside the light guide section.

According to such a configuration, when the light emitted from the light source enters the inside of the light guide member from the longitudinal end, the light is transmitted to the first light guide portion of the light guide member and the two first light guide portions. 2
The light is emitted from substantially the entire length area of the first side face facing the image reading area while traveling inside the respective light guide sections in the longitudinal direction thereof. Therefore, it is possible to appropriately irradiate the light in various places in the longitudinal direction of the image reading area.
When the light applied to the image reading area is reflected by the surface of the original, the light passes through the first light guide portion of the light guide member, reaches the lens array, and is focused on the light receiving element surface. Becomes

In another preferred embodiment of the present invention,
Each of the second light guides has a second side surface that scatters and reflects light traveling in the second light guide, and a third side that reflects light traveling from the second side surface toward the image reading area.
A configuration in which a side surface is provided can be adopted.

According to such a configuration, when the light emitted from the light source travels in each of the second light guides, the light is scattered and reflected by the second side surface, and a part of the light is reflected on the third side surface. To reach. Then, the third side surface reflects the light toward the image reading area. Therefore,
Most of the light emitted from the light source and incident on the light guide member can be efficiently radiated to the image reading area.

In another preferred embodiment of the present invention,
The third side surface is a surface connecting a curved surface or a plurality of planes having different inclination angles that reflect light traveling from the second side surface to the third side surface so as to be focused on the image reading area or the vicinity thereof. A certain configuration can be adopted.

According to such a configuration, the light that travels in each second light guide portion of the light guide member and is scattered and reflected by the second side surface is formed by connecting a plurality of planes having different curved surfaces or different inclination angles. When the light reaches the third side surface formed in the shape, the light is reflected by the third side surface and converges on the image reading area or in the vicinity thereof. Therefore, it is possible to irradiate the image reading area with light more intensively, which is preferable in increasing the illuminance of the image reading area.

In another preferred embodiment of the present invention,
The light source may be provided at a position overlapping each of the lens array and the plurality of light receiving elements in the sub-scanning direction.

According to such a configuration, the light source can be prevented from being greatly bulky in the sub-scanning direction with respect to the lens array and the plurality of light receiving elements, so that the size of the entire image reading apparatus can be further reduced. .

In another preferred embodiment of the present invention,
A circuit board may be provided with the plurality of light receiving elements mounted thereon, and the light source may be mounted on the circuit board.

According to such a configuration, since a plurality of light receiving elements and a light source are mounted on one circuit board, the number of components as a whole can be reduced and the configuration can be simplified. Therefore, it is useful for reducing the manufacturing cost of the image reading device.

In another preferred embodiment of the present invention,
The light guide member may include a light reflection member that covers a side surface of the light guide member.

According to such a configuration, when the light emitted from the light source is made to enter the inside of the light guide member and is emitted from the first side surface while traveling in the longitudinal direction of the light guide member, The light reflecting member can prevent light traveling inside the light member from leaking from the other side surface of the light guide member to the outside. Therefore, the amount of light emitted from the first side surface of the light guide member toward the image reading region can be increased by the amount of light leakage from the light guide member, and the amount of light with respect to the image reading region can be increased. Irradiation efficiency can be further increased.

The features and advantages of the present invention will become more apparent from the following description of embodiments.

[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 sectional view showing an example of an image reading apparatus 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. FIG. 4 is an exploded perspective view of the image reading device shown in FIG.

The image reading device A of the present embodiment is configured as a contact type image sensor. As shown in FIG. 4, the image reading device A includes a housing 2,
Circuit board 3 on which a plurality of sensor IC chips 4 are mounted, LE
It comprises a D light source 5, a document guide plate 20, a light guide member 1, a lens array 6, and a pair of light reflection members 7A and 7B. As will be described later, the sensor IC chip 4 has a plurality of light receiving elements 40.

The housing 2 is formed in an elongated box shape having a housing portion 21 having an upper surface opening. The above-described components of the image reading apparatus A are assembled to the housing 2. The document guide plate 20 is for arranging a document to be read as opposed to a document, and is made of, for example, transparent glass or synthetic resin. The document guide plate 20 is mounted on the upper surface of the housing 2 so as to close the upper part of the housing 21 of the housing 2. A linear area immediately above the lens array 6 on the upper surface of the document guide plate 20 is an image reading area P (see FIG. 2). For example, a platen roller 8 is disposed on the upper surface of the document guide plate 20, and the document K is transported by the platen roller 8 in the sub-scanning direction.

FIG. 5 is a schematic perspective view, partially in section, showing the light guide member 1. FIG. 6 is a sectional view taken along line VI-VI of FIG.
FIG. 7 is a sectional view taken along line VII-VII of FIG. FIG.
VIII-VIII sectional drawing of FIG.

The light guide member 1 is for efficiently guiding the light emitted from the LED light source 5 to the entire length of the linear image reading area P. The light guide member 1 includes a transparent member 10 obtained by molding an acrylic transparent resin such as PMMA, and the surface of each part is a mirror surface. If the surface of the transparent member is made to be a mirror surface, when light is guided inside the transparent member, light rays incident on the surface of the transparent member 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, a light ray incident at an angle smaller than the critical angle for total reflection can be transmitted as it is to the outside of the transparent member. In addition,
The mirror surface does not necessarily need to be a surface whose surface is actively polished. For example, when a transparent member is resin-molded using a mold, it is a relatively smooth surface obtained by resin molding. You may.

The light guide member 1 has an auxiliary region Sb at one longitudinal end of the light guide member 1 and a main region Sa other than the auxiliary region Sb.
And can be divided into The auxiliary area Sb is LE
It is a part that plays a role in advancing light emitted from the D light source 5 into the main area Sa. The auxiliary area Sb is provided with a downward projection 13, a downward bottom surface 14, two tapered surfaces 16a and 16b connected to the end surface 15, and the like. The bottom surface 14 is a surface on which the LED light sources 5 are arranged to face each other, and light emitted from the LED light sources 5
4 and enters the light guide member 1. As shown in FIG. 7, the tapered surfaces 16a and 16b are flat or curved surfaces capable of totally reflecting light transmitted through the bottom surface 14 toward the main region Sa of the light guide member 1. is there. The protruding portion 13 is positioned below the bottom surface 14 by L
This is useful for securing a space for disposing the ED light source 5.

The main region Sa has a substantially uniform cross-sectional shape at various points in the longitudinal direction, and includes a first light guide portion 11A extending in a fixed direction and two second light guide portions 11B, 11B. I have. As is clearly shown in FIG.
The light guides 11B, 11B are connected so as to protrude downward from both ends in the width direction of the first light guide 11A, and the two second light guides 11B, 11B are connected to the light guide member 1B. Are facing each other at a constant interval in the width direction of. For this reason, between the second light guide portions 11B, 11B, a concave groove portion 12 having an open bottom surface is formed to extend in the longitudinal direction of the light guide member 1.

The side surfaces of the main region Sa of the light guide member 1 include a first side surface 10A, second side surfaces 10B, 10B, and a third side surface 10B.
There are side surfaces 10C, 10C, fourth side surfaces 10D, 10D, fifth side surfaces 10E, 10E as inner wall surfaces of the concave groove portion 12, and sixth side surfaces 10F. The first side surface 10A is an upward flat surface of the first light guide 11A, and the first side surface 10A serves as a light emission surface that emits light toward the image reading area P. The second side surfaces 10B, 10B correspond to the bottom surfaces of the second light guide portions 11B, 11B, respectively, and as shown well in FIG. 7, these second side surfaces 10B, 10B.
Are provided with a plurality of groove-shaped recesses 17 having an arc-shaped cross section at appropriate intervals. The region between the plurality of recesses 17 is a mirror-like plane. The plurality of recesses 17
Plays a role of causing the light traveling in the light guide member 1 to be scattered and reflected or reflected in a state close to the scattered light, thereby rapidly changing the traveling angle of the light and causing most of the light to be emitted from the first side surface 10A. Part. The second side surface 10
Other means for abruptly changing the advancing angle of the light that has reached B include means for providing a plurality of protrusions on the second side face 10B at appropriate intervals, and a method for scattering and reflecting light from the second side face 10B. And a means for forming the second side surface 10B into a rough surface with minute unevenness.

The third side surfaces 10C, 10C are formed so as to face each of the two second side surfaces 10B, 10B at an inclined angle, and advance from the second side surfaces 10B, 10B. The first side 10A
Is a surface that reflects toward the central portion in the width direction. As is clearly shown in FIG. 8, the two fifth side surfaces 10E, 10E
E has an inclined surface 18 at a longitudinal end near the auxiliary region Sb.
a, 18a are formed. Also, two fourth side surfaces 1
The inclined surfaces 18b, 18b are also formed in the portions of OD and 10D that face the inclined surfaces 18a, 18a. The inclined surface 18a of each of the fifth side surfaces 10E serves to reflect light traveling from the auxiliary region Sb toward the main region Sa in the direction of the fourth side surface 10D. The surface 18b is a part that plays a role in further reflecting the light and traveling toward the other end in the longitudinal direction of the light guide member 1.

The light guide member 1 is provided on the bottom surface 1 of the auxiliary area Sb.
The light incident on the inside of the first side surface 4 is emitted from the substantially entire region of the first side surface 10A. Specifically, as shown in FIG.
When light emitted upward from the ED light source 5 at an appropriate spread angle enters the light guide member 1 from the bottom surface 14, the light is reflected by the tapered surfaces 16a and 16b and proceeds into the main region Sa. Then, the light reaches the end face 10G at the other longitudinal end of the light guide member 1 while repeating total reflection by the plurality of side faces 10A to 10F of the main region Sa. However, when light is incident on the second side surface 10B, the light incident on each of the concave portions 17 is reflected so as to change the course of the light rapidly, and a part of the reflected light reaches the third side surface 10C. As a result, the other part of the light directly reaches the first side face 10A without reaching the third side face 10C, and most of the light is transmitted to the first side face 10A.
The light enters the side surface 10A at an incident angle smaller than the critical angle for total reflection. As a result, light is emitted upward from various points along the entire length of the first side surface 10A in the longitudinal direction. As is well shown in FIG. 2, the light guide member 1 is
The first side surface 10 </ b> A is provided in the housing portion 21 of the housing 2 so as to face the image reading area P below the document guide plate 20. Therefore,
Light emitted from the first side surface 10A can be appropriately applied to the image reading area P.

The lens array 6 is provided with the first light guide member 1.
The light emitted from the side surface 10A to the image reading area P and reflected by the document K on the document guide plate 20 is focused on each surface of the plurality of light receiving elements 40 to form an image. As the lens array 6, for example, a lens array having a structure in which a large number of rod lenses capable of converging an original image to an erect equal magnification are arranged in a row and held by a holder made of synthetic resin or the like is applied. The lens array 6 is arranged in the housing 21 of the housing 2 in a state of being fitted in the concave groove 12 of the light guide member 1. These lens arrays 6
The light guide member 1 and the light guide member 1 are both set to extend in the main scanning direction.

The pair of light reflecting members 7A and 7B are formed to have dimensions substantially the same as the entire length of the light guiding member 1. For example, the surface has a light reflectance of about 97% or 98%. Is made of a white synthetic resin having a high light reflectance. These one set of light reflecting members 7A and 7B has a shape capable of sandwiching the light guide member 1 from both sides in the width direction of the light guide member 1, and the main region Sa of the light guide member 1 has the same shape. The third side surfaces 10C, 10C, the fourth side surfaces 10D, 10D, and the second side surfaces 10B, 10B can be covered. Further, the light reflecting members 7A, 7B
As is well shown in FIG. 1, the auxiliary region Sb of the light guide member 1 has its end face 15 and two tapered faces 16.
It is configured to cover each side surface other than the bottom surface 14, such as a and 16b. Further, the light reflecting members 7A,
At one end in the longitudinal direction of 7B, a wall surface 70 facing the end face 10G of the other end in the longitudinal direction of the light guide member 1 is also provided.
These light reflecting members 7A and 7B are fitted into the housing portion 21 of the housing 2 with the light guide member 1 sandwiched from the left and right so as to cover a predetermined side surface of the light guide member 1.

The plurality of sensor IC chips 4 are formed by integrally forming a plurality of light receiving elements 40 on one surface of a semiconductor chip, and the light collected by the lens array 6 is received by the light receiving elements 40. Thus, the photoelectric conversion is performed, and an image signal having an output level corresponding to the amount of received light is output. The plurality of sensor IC chips 4 are mounted in a row in the longitudinal direction of the circuit board 3.

The LED light source 5 includes, for example, R, G, B
The three types of LED chips that emit light of each color are collectively packaged in a resin, and are capable of reading color images. The LED light source 5 is mounted on the mounting surface of the circuit board 3 on which the sensor IC chip 4 is mounted, and its mounting position overlaps the sensor IC chip 4 in the sub-scanning direction, as is clearly shown in FIG. Position.

The circuit board 3 includes the plurality of light receiving elements 4
0 is located immediately below the lens array 6 and the LED
The light source 5 is assembled to the bottom of the housing 2 so as to face the bottom surface 14 of the light guide member 1. On the surface of the circuit board 3, a conductive wiring pattern (not shown) for inputting and outputting signals to the plurality of sensor IC chips 4 and the LED light source 5 and for supplying power is formed. Can be connected via the connector 31.

Next, the operation of the image reading apparatus A will be described.

First, in FIG. 2, in the image reading apparatus A, since the lens array 6 is fitted into the concave groove 12 of the light guide member 1, the lens array 6 and the light guide member 1 are sub-scanned. Unlike the case in which the lens array 6 and the light guide member 1 are arranged at intervals in the direction, it is possible to prevent the lens array 6 and the light guide member 1 from becoming bulky in the sub-scanning direction as much as possible. For this reason, the width of the housing portion 21 of the housing 2 that houses the lens array 6 and the light guide member 1 may be a relatively small size, and the width of the housing 2 and thus the entire width of the image reading device A may be reduced. It is possible to do. Also, as for the LED light source 5, the lens array 6 and the plurality of sensor IC chips 4 are used.
Since it is arranged at a position overlapping with 0 in the sub-scanning direction, it is not necessary to increase the width of the circuit board 3, which can also reduce the overall size of the image reading apparatus A.

On the other hand, the lens array 6 includes the light guide member 1.
The outer surfaces 60a and 60b facing the sub-scanning direction in the left-right width direction are in contact with the inner wall surface of the groove 12 and are directly supported by the light guide member 1. . Therefore, the lens array 6 can be accurately placed and fixed at a desired position after being set in a predetermined standing posture without using a dedicated support member. That is, one set of light reflecting members 7A, 7B
Plays a role in positioning and fixing the light guide member 1, but when the light guide members 1 are positioned and fixed by the light reflecting members 7A and 7B, the lens array 6 is also positioned and fixed at the same time. . Even if a slight vibration or the like occurs in the image reading apparatus A, the lens array 6 is not easily displaced or its standing posture is destroyed.

Further, in the image reading apparatus A, the reading operation of the original image can be appropriately performed. That is, when the LED light source 5 is driven to light, the light emitted from the LED light source 5 enters the light guide member 1 from the bottom surface 14 of the auxiliary area Sb of the light guide member 1. Then the light
As described above, while traveling toward the other end of the light guide member 1 in the longitudinal direction, the light exits from various locations in the substantially entire length area of the first side surface 10A,
The surface of the original K in the line-shaped image reading area P is efficiently irradiated. The light reflected by the document K then passes through the first light guide portion 11A of the light guide member 1 and is focused by the lens array 6 to form the sensor IC chip 4
, And a predetermined image signal is output. Since the above-described predetermined side surface of the light guide member 1 is surrounded by the light reflection members 7A and 7B having high light reflectance, light traveling in the light guide member 1 is first.
Leakage to the outside of the light guide member 1 from a side surface different from the side surface 10A can be prevented. Therefore, the efficiency of light irradiation on the image reading area P can be further increased.

FIGS. 9 and 10 are sectional views showing another example of the image reading apparatus according to the present invention. Note that FIG.
In the following drawings, the same parts as those in the previous embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the image reading apparatus Aa shown in FIG. 9, the entire or substantially the entire outer surface of each of the second light guide portions 11B and 11B of the light guide member 1A is defined as a third side surface 10C ', and the third side surface 10C' is defined as the third side surface 10C '. It is formed in a curved shape. Further, the cross-sectional shape of the pair of light reflecting members 7A 'and 7B' is also a shape corresponding thereto. The third side surface 10C ′ is connected to the second side surface 10B.
Is a curved surface that reflects so that light that has traveled from above is focused on the image reading area P or a position (focal point) near the image reading area P. According to such a configuration, it is possible to more intensively irradiate the image reading area P with light, which is preferable in increasing the illuminance of the image reading area P. As a means for irradiating the image reading area P with light intensively, for example, the third
Means for forming the side surface 10C 'on a surface obtained by connecting a plurality of planes having different inclination angles in a substantially curved shape may be employed.
Even with such means, it is possible to approximately converge the light reflected by the surface at a predetermined position (focal point).

In the image reading device Ab shown in FIG.
One second light guide portion 11A of the light guide member 1B
It has a structure in which only the light guide 11B is continuously provided. Also,
As the light reflecting member, only one light reflecting member 7A is used. Even with such a structure, the second light guide is formed while the light emitted from the LED light source travels in the longitudinal direction inside the first light guide 11A and the second light guide 11B of the light guide member 1B. The light scattered and reflected by the second side surface 10B of the portion 11B can be appropriately applied to the image reading region P from the first side surface of the first light guide portion 11A.
If such a structure is adopted, the overall size of the image reading apparatus can be further reduced by the amount that the width of the light guide member 1B can be made smaller than that of the light guide members 1 and 1A of the previous embodiment. Becomes Furthermore, in this image reading device Ab, the two outer surfaces 60a,
Only one of the outer surfaces 60a of the housing 60b is supported by the light guide member 1B, and the other outer surface 60b is supported by the inner wall surface of the housing 21B of the housing 2. It may be a simple structure. Even with such a structure, the lens array 6 and the light guide member 1
B can be prevented from becoming bulky in the sub-scanning direction, and one side of the lens array 6 is connected to the light guide member 1.
B can be supported, and the object of the present invention can be achieved.

FIGS. 11 and 12 are explanatory views showing other examples of the combination structure of the light guide member and the light source applied to the image reading apparatus according to the present invention.

In the structure shown in FIG. 11, the light source 5 is opposed to the bottom surfaces 14 at both ends in the longitudinal direction of the light guide member 1C, and light enters the light guide member 1C from those two positions. It is configured to be able to. With such a configuration, the amount of incident light into the light guide member 1C can be increased, which is advantageous in increasing the illuminance of the image reading area. Thus, in the present invention, the specific number of light sources is not limited.

In the structure shown in FIG. 12, the light source 5 is opposed to the end faces 10H at both ends in the longitudinal direction of the light guide member 1D.
With such a configuration, the end face 1 emitted from the light source 5
Most of the light transmitted through the light guide member 1D can be allowed to travel in the longitudinal direction of the light guide member 1D as it is.
Light can be appropriately emitted from various portions of the first side surface 10A. As described above, in the present invention, the specific configuration of the part of the light guide member from which the light emitted from the light source enters the light guide member is not particularly limited.

In addition, the specific configuration of each part of the image reading apparatus according to the present invention is not limited to the above-described embodiment, and various design changes can be made. For example, in the above-described embodiment, the light emitted from the first side surface of the light guide member is directly applied to the image reading area. However, the present invention is not limited to this. The light emitted from the side surface may be reflected by a reflection mirror or the like and then applied to the image reading area. Further, the image reading apparatus according to the present invention may be configured as a contact image sensor used as a handy scanner, for example, instead of being configured as a contact image sensor arranged to face the platen roller. In addition, for example, a so-called flatbed type image sensor may be configured in which the housing is provided so as to be relatively movable in the sub-scanning direction with respect to the document placing plate. Further, according to the present invention, a light source other than the LED light source can be used as the light source, and the image reading device can be configured to read a so-called monochrome image instead of reading a color document. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an image reading apparatus 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 exploded perspective view of the image reading apparatus shown in FIG.

FIG. 5 is a schematic partial cross-sectional perspective view showing an example of a light guide member applied to the image reading apparatus according to the present invention.

FIG. 6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is a sectional view taken along line VII-VII of FIG. 5;

FIG. 8 is a sectional view taken along line VIII-VIII of FIG. 7;

FIG. 9 is a sectional view showing another example of the image reading apparatus according to the present invention.

FIG. 10 is a sectional view showing another example of the image reading apparatus according to the present invention.

FIG. 11 is an explanatory view showing another example of the combination structure of the light guide member and the light source applied to the image reading apparatus according to the present invention.

FIG. 12 is an explanatory diagram showing another example of the combination structure of the light guide member and the light source applied to the image reading apparatus according to the present invention.

FIG. 13 is a cross-sectional view showing an example of the image reading apparatus proposed by the applicant of the present application.

14 is an explanatory diagram showing a combination structure of a light guide member and a light source used in the image reading device shown in FIG.

FIG. 15 is an explanatory diagram showing a traveling state of light in the combination structure of the light guide member and the light source shown in FIG.

[Explanation of symbols]

 A, Aa, Ab Image reading device K Document P Document reading area 1, 1A to 1D Light guide member 2 Housing 3 Circuit board 5 Light source 6 Lens array 7A, 7B Light reflecting member 10A First side surface 10B Second side surface 10C Third Side surface 11A First light guide 11B Second light guide 12 Concave groove 21 Housing 60a, 60b Outer surface (of lens array)

Claims (8)

[Claims] 1. A light source, and a plurality of side surfaces extending in a main scanning direction, reflecting light emitted from the light source and entering the inside so that the light emitted from the light source irradiates a linear image reading area. By causing the light to travel in the main scanning direction while emitting the light from a fixed length region of the first side surface of the plurality of side surfaces, the light reflected from the image reading region is focused to form an image. A lens array extending in the main scanning direction for performing an image, a plurality of light receiving elements for receiving light converged by the lens array and performing photoelectric conversion, and a housing for housing the lens array and the light guide member A housing having a portion, wherein at least one side surface of each of the lens array and the light guide member facing the sub-scanning direction is in opposing contact with each other. And a side in contact with the light guide member of said lens array is characterized in that it is supported by the light guide member, the image reading apparatus. 2. The light guide member includes a first light guide portion extending in a longitudinal direction of the light guide member, and two second light guide portions connected to the first light guide portion. 2
A concave groove is formed between the two second light guides, and both outer surfaces in the width direction of the lens array are formed by the light guide member by fitting the lens array into the concave groove. The image reading device according to claim 1, which is supported. 3. The first light guide of the light guide member is disposed between the image reading area and the lens array, and a surface of the side of the first light guide facing the image reading area. Is the first side surface, and the light guide member is configured to receive light emitted from the light source and entering the light guide member from the longitudinal end of the light guide member into the two second light guide members. The first light guide section while traveling inside the first light guide section.
The image reading device according to claim 2, wherein the image reading device is configured to emit light from substantially the entire length region of the side surface. 4. Each of the second light guides has a second side surface for scattering and reflecting light traveling in the second light guide, and a second side surface.
The image reading device according to claim 3, further comprising: a third side surface configured to reflect light traveling from a side surface toward the image reading area. 5. The third side surface is a curved surface or a plurality of planes having different inclination angles for reflecting light traveling from the second side surface to the third side surface so as to be focused on or near the image reading area. 5. The surface connected to
An image reading device according to claim 1. 6. The image reading device according to claim 1, wherein the light source is provided at a position overlapping each of the lens array and the plurality of light receiving elements in the sub-scanning direction. 7. The image reading device according to claim 1, further comprising a circuit board on which the plurality of light receiving elements are mounted, and wherein the light source is mounted on the circuit board. 8. The image reading device according to claim 1, further comprising a light reflection member that covers a side surface of the light guide member.