JP3138845B2 - Image sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called close contact type image sensor used for reading a document surface as image information, for example, in a facsimile or image reader.

As shown in the drawings of this application, this type of close contact type image sensor directly contacts an original with a transparent plate provided on one surface of a frame, and emits light from a light emitting element disposed in the frame. The received light reflected from the original surface is focused on a light receiving element in the frame.
More specifically, the light-emitting element is arranged so as to irradiate illumination light in an oblique direction toward a document reading unit at a portion relatively close to the document surface in order to enhance the illumination efficiency of the document surface. The light reflected from the portion is configured to be collected at an equal magnification on a light receiving element disposed on a substrate below the frame by a lens array having an optical axis arranged in the thickness direction of the frame.

The light receiving elements are bonded to a substrate in a bare chip shape, and wire bonding is performed between each light receiving element and a wiring pattern on the substrate. Wiring patterns on the board are collected on a part of the board, and conventionally, a commercially available connector is connected by soldering to connect with external wiring.

[0004] The substrate is conventionally attached to the lower portion of the frame by means such as bonding.

[0005] By the way, the demand for smaller and lighter devices such as facsimile machines and image readers has been further strengthened, and for this purpose, the miniaturization of such contact image sensors has also been demanded. By the way, as described above, a special lens array for condensing the reflected light from the original reading section to the light receiving element at the same size as the erect is used in this image sensor. Since the length is specified, it has been considered difficult to shorten the frame itself in the thickness direction.

As described above, the wiring for outputting the image reading signal is obtained by attaching a commercially available connector to the substrate on which the light receiving element is mounted, and connecting the wiring via the connector. I have. However, the thickness of the connector increases the thickness dimension of the entire image sensor, which also makes it difficult to reduce the dimension of the image sensor in the thickness direction.

[0007] The wiring connection method using a commercially available connector as described above also has a problem that the number of parts increases and the cost increases.

Further, the mounting of the substrate on which the light receiving element is mounted to the frame by bonding has a problem in maintaining the mounting stability for a long period of time.
There was also a problem that workability was poor.

The present invention has been conceived in view of the above-mentioned circumstances, and allows a substrate on which a light receiving element is mounted to be mounted on a frame with good workability, and allows a connection between the substrate and external wiring. It is an object of the present invention to provide an image sensor which can omit a connector in connection and achieve downsizing and cost reduction by this.

[0010]

Means for Solving the Problems To solve the above problems, the present invention takes the following technical means.

That is, in the invention described in claim 1 of the present application, a transparent plate for contacting a read original is disposed on one surface side of the frame, and the inside of the frame is irradiated with illumination light toward the read original. A light-emitting element, a lens array for condensing light reflected from the read original, and a light-receiving element mounted on a substrate so as to receive light condensed by the lens array, the image sensor, The board is mounted on the other side of the frame by elastically pressing the rigid support member disposed on the back side of the board against the frame by a spring member, and is formed on the flat cable and the board by utilizing the elasticity of the spring member. And the above-mentioned terminal portions are pressed and connected to each other.

According to a second aspect of the present invention, in the image sensor according to the first aspect, the terminal portion is formed on an upper surface edge of the substrate, and is provided between the terminal portion and a frame. By inserting the flat cable, mutual pressing connection between the flat cable and the terminal portion of the board is achieved.

Further, according to a third aspect of the present invention, in the image sensor of the first aspect, the terminal portion is formed on a rear edge of the substrate, and the rigid support member and the terminal portion are formed. By inserting the flat cable between them, mutual press connection between the flat cable and the board-shaped terminal portion is achieved.

[0014]

In the image sensor according to the present invention, a rigid support member is disposed on the back side of the substrate when the substrate on which the light receiving element is mounted is attached to the frame, and this is elastically pressed against the frame by a spring member. Like that. Therefore, even when the spring member is used in the longitudinal direction of the frame, the substrate can be held in contact with the frame with a uniform pressing force over the longitudinal direction via the rigid support member. Since the elasticity is used within the elastic limit of the spring member, the mounting stability of the substrate to the frame is as follows.
It is constant over a long period. Also, by using the self-locking type spring member, the work of attaching the substrate to the frame can be performed with good workability as compared with the case of using a screw or an adhesive.

Further, in the present invention, the mutual pressing connection between the terminal portion formed on the substrate and the flat cable is achieved by utilizing the elastic pressing force given by the spring member. The substrate is mounted by elastically pressing a rigid support member disposed on the back side thereof toward the frame side. Therefore, between the frame and the board, and
An elastic mutual pressing force always acts between the substrate and the rigid support member. In the present invention, the mutual pressing force is utilized so that the flat cable is elastically held between these members, and the mutual pressing connection between the flat cable and the terminal portion on the board is made. Is being planned.

According to the second aspect of the present invention, when the terminal portion is formed on the same upper surface edge as the surface to which the light receiving element is bonded, the mutual elastic pressing force between the substrate and the frame is used. A flat cable is inserted between them.

According to a third aspect of the present invention, in the case where the terminal portion is formed on the rear edge opposite to the surface to which the light receiving element is bonded via a through hole or the like, the terminal portion is formed on the rear side of the substrate. A flat cable is inserted between the rigid support member and an elastic pressing force acting between the rigid support members.

As described above, in the present invention, a flat cable is selected as the wiring to be connected to the board, and is simply inserted between the members which are elastically pressed to each other as described above. Since the connection between the board and the wiring is aimed at, firstly, the conventional connector is omitted, and the cost can be reduced accordingly.
Since the connector is omitted, the dimension in the thickness direction of the frame can be omitted, and the size of the image sensor can be reduced accordingly. In addition, the work of connecting the cables can be achieved simply by inserting the flat cable into a predetermined portion, and the workability is excellent.

As described above, according to the image sensor of the present invention, the workability of attaching the substrate on which the light receiving element is mounted to the frame is remarkably improved, and at the same time, the connector is omitted when connecting to the external wiring. By
The cost can be reduced by reducing the number of parts and improving the workability, and the size reduction of the image sensor itself, particularly in the thickness direction, can be promoted.

[0020]

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

FIGS. 1 to 5 show a first embodiment of the image sensor 1 of the present invention. A transparent plate 3 made of a glass plate or the like is attached to the upper surface of the frame 2 having a substantially rectangular cross section by bonding or the like. The document 4 to be read is transported at least at the reading position 3a of the transparent plate 3 so as to be in contact with the surface of the transparent plate 3 while being backed up by the platen 5 or the like.

The frame 2 can be made by extrusion molding using aluminum or resin as a material, or by resin injection molding.

Inside the frame 2, a light emitting element 6 for irradiating the illumination light toward the original 4 brought into contact with the transparent plate 3 as described above, and a light reflected from the reading position 3a are erected. A lens array 7 that converges the light twice and a light receiving element 8 that receives the reflected light condensed by the lens array 7 are provided.

The light-emitting element 6 is disposed at a position diagonally lower than the reading position 3a on the transparent plate 3, and irradiates the original so that the distance from the transparent plate 3 is relatively short. Light intensity can be increased.

As the light emitting element 6, for example, an element in which an LED chip is sealed with a transparent resin is used, and is fixed on the substrate 9 at equal intervals by soldering or the like.

On the other hand, the light receiving element 8 has the form of an array chip in which unit light receiving elements such as photodiodes are integrally formed on a silicon substrate at minute intervals, and has a small coefficient of thermal expansion in a bare chip state. The substrate is directly bonded to the ceramic substrate or the glass epoxy substrate 10, and the wiring on the substrate is connected by wire bonding.

Further, the lens array 7 arranged on the straight line in the vertical direction connecting the light receiving element 8 and the reading position 3a on the transparent plate 3 as described above Is held in close contact with a holding wall 11 formed so as to grip the holding member. The substrate 9 on which the light receiving element 8 is mounted is attached to the frame 2 by pressing a rigid support member 12 attached to the rear surface of the substrate 2 with a spring member 13 on the lower surface of the frame 2.

That is, the rigid support member 12 includes a substantially flat plate portion 12a along the back surface of the substrate 10, and a rib 12b rising from one side edge of the substantially flat plate portion in an L shape. Thereby, the section modulus is increased, and the rigidity against bending is significantly increased.

On the other hand, the spring member 13 has a form in which a band-shaped spring plate is bent into an M shape as shown in FIG. 3, and the M-shaped legs 13a, 13a have engagement holes 14,
14 are formed. Engagement projections 15, 15 for ratchet engagement with the respective engagement holes 14, 14 of the spring member 13 are formed on the side surfaces cut off on both sides of the frame 2. This spring member 13 can be provided at, for example, two places in the longitudinal direction of the frame.

As can be seen from the above description, in this embodiment, the work of attaching the substrate 10 on which the light receiving element 8 is mounted to the frame 2 is performed in the state where the rigid support member 12 is attached to the back surface. The leaf spring member 13 is pushed in the direction of the arrow in FIG.
May be ratchet-engaged with the engagement protrusions 15, 15. When the engagement state between the engagement projection 15 and the engagement hole 14 is achieved, the spring member 13 is no longer prevented from coming off. The spring member 13 is bent in an M-shape, and the V-shaped intermediate bent portion is formed by the rigid support member 12.
In order to elastically press the substrate 10 against the lower surface of the frame 2, the engagement hole 14 and the engagement protrusion 1 are formed so that the M-shaped spring member 13 is elastically deformed in the mounted state.
Needless to say, the positional relationship with 5 is set.

On the rear side edge of the substrate 10, there is formed a terminal portion 16 which is electrically connected to a wiring pattern on the upper surface of the substrate through a through hole (not shown) or the like. Of course, the terminal section 16 is also provided with a terminal section for supplying power to the light emitting element 6, and the wiring to the substrate 9 on which the light emitting element 6 is mounted passes through the frame 2. It is connected to the substrate 10 on which the light receiving element 8 is mounted by providing wiring or the like.

On the other hand, the rigid support member 12 is provided with a swelling deformation portion 12c so as to face the region where the terminal portion 16 is provided, and the inner surface of the swelling deformation portion 12c and the terminal portion 16 are provided. , A certain gap is formed.

In the gap, a so-called FFC is provided.
An end of a flat cable 17 such as a cable called (flexible flat cable) is inserted. In addition, what is called a card wire can also be used for the plate cable 17. This flat cable 1
Reference numeral 7 denotes a form in which a conductor wiring layer is formed in an insulated state on a flexible thin-plate resin base, and its end is exposed. In the embodiment, this flat cable 17 is used.
The exposed terminal portion is formed on the upper surface of the end portion. When the flat cable 17 is inserted as shown in FIG.
The side terminal portions 16 are pressed against each other.

In this case, the thickness of the flat cable 17 depends on the terminal portion 16 of the substrate 10 and the rigid support member 12.
Is slightly larger than the gap between the inner surfaces of the bulging deformation portions 12c provided on the substrate 10. When the flat cable 17 is inserted, the cable 17 And rigid support member 12
Between them. Thereby, a reliable contact state between the terminal portion 16 on the substrate side and the terminal portion on the cable side is ensured.

FIGS. 6 to 8 are sectional views showing a second embodiment of the present invention. The difference between the second embodiment and the first embodiment is that a terminal portion 16 on the substrate 10 on which the light receiving element 8 is mounted is to be connected to a flat cable.
Is formed at the edge of the same upper surface as the surface on which the light receiving element 8 is mounted. The method of attaching the substrate 10 to the frame 2 is the same as in the first embodiment.
An L-shaped plate-shaped rigid support member 12 attached to the back side of the substrate 10 is elastically pressed against the frame side by an M-shaped spring member 13.

A notch 18 is provided in the frame 2 at a portion corresponding to the portion where the terminal portion 16 is provided, and a projection 19 is formed on the lower surface of the notch. The gap between the top of the projection 19 and the substrate 10 is set slightly smaller than the thickness of the flat cable 17. Then, the flat cable 17 is inserted into the gap between the projection 19 and the substrate 10. In this state, the flat cable 17 is pinched between the terminal portion 16 of the substrate 10 and the convex portion 19 by the elasticity of the spring member 13. Thereby, the terminal 1 on the substrate side
6 and the terminal portion on the side of the flat cable can be surely contacted.

As described above, in the image sensor 1 of the present invention, the workability of attaching the substrate 10 on which the light receiving element 8 is mounted to the frame 2 is very good, and the elastic pressing of the substrate 10 against the frame is very good. The pressure becomes stable for a long time.

Since the flat cable 17 is elastically held by utilizing the elasticity of the spring member 13, the connection between the cable and the terminal portion 16 provided on the substrate 10 is achieved. Unlike the related art, a connector is not required, and the connection of the flat cable 17 can be achieved only by a simple operation of inserting the flat cable 17 into a predetermined portion.

In particular, since the conventional connector is not required, the image sensor 1 can be made more compact in the thickness direction, and the cost reduction effect due to the reduction in the number of parts and the improvement in workability is remarkable. .

Of course, the scope of the present invention is not limited to the embodiment described above. The present invention is characterized by a structure for mounting a light receiving element on a board to a frame, and a connection structure between a terminal portion provided on the board and a flat cable. The arrangement of the light emitting element or the lens array is not limited at all.

[Brief description of the drawings]

FIG. 1 is a front view of a first embodiment of an image sensor according to the present invention.

FIG. 2 is a rear view of the image sensor of FIG. 1;

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV in FIG. 2;

FIG. 5 is an enlarged view of a main part of FIG.

FIG. 6 is a rear view of a second embodiment of the image sensor of the present invention.

FIG. 7 is a sectional view taken along line VII-VII in FIG.

FIG. 8 is a sectional view taken along the line VIII-VIII in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image sensor 2 Frame 3 Transparent plate 4 Document 6 Light emitting element 7 Lens array 8 Light receiving element 10 Substrate 12 Rigid support member 13 Spring member 16 Terminal part 17 Flat cable

Claims (3)

(57) [Claims] A transparent plate for contacting a document to be read is arranged on one side of a frame, and inside the frame,
A light-emitting element that irradiates illumination light toward the read original, a lens array that collects reflected light from the read original, and a light-emitting element mounted on the substrate so as to receive the light collected by the lens array An image sensor comprising a light receiving element, wherein the substrate is attached to the other surface of the frame by elastically pressing a rigid support member disposed on the back side of the substrate with a spring member, and utilizes the elasticity of the spring member. An image sensor, wherein the flat cable and the terminal portion formed on the substrate are pressed and connected to each other. 2. The terminal portion is formed on an upper surface edge of the board, and the flat cable is inserted between the terminal portion and a frame, so that the flat cable and a terminal of the board are inserted. 2. The image sensor according to claim 1, wherein a mutual pressing connection is established between the first and second parts. 3. The terminal portion is formed on a rear edge portion of the substrate, and the flat cable is inserted between the rigid support member and the terminal portion so as to be connected to the flat cable. 2. The image sensor according to claim 1, wherein a mutual pressing connection is established between the terminal and the substrate.