JPH04243163A - Close contact type image sensor - Google Patents

Abstract

PURPOSE:To scarcely affect influence of stray light from the end face of a board to a photodetector without increasing the area of the board and a manufacturing cost in a close contact type image sensor in which a photodetector is divided into blocks and matrix-driven. CONSTITUTION:Matrix wirings 5a, 5b are divided to both sides of a photodetector 2. Thus, since the photodetector 2 can be disposed near the center of a board without increasing the substrate 1 and its cost, influence of tray light from the end face of the board can be reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact type image sensor used in an image reading section of a facsimile machine, and more particularly to a contact type image sensor in which a light receiving element is divided into blocks and driven in a matrix.

0002

2. Description of the Related Art A conventional example of this type of contact type image sensor will be explained with reference to FIG.

In FIG. 3, reference numeral 1 denotes a transparent substrate such as a glass substrate, on which a large number of light receiving elements (photoelectric conversion elements) are mounted.
2 are arranged in a straight line at regular intervals. The light-receiving elements 2 are divided into blocks of a certain number (6 in this example), and a common electrode 3 is provided corresponding to each block, and an individual electrode 4 is provided corresponding to each light-receiving element 2. It is being The common electrode 3 is connected to one end of the light receiving element 2, and the individual electrode 4 is connected to the other end of the light receiving element 2.

Reference numeral 5 denotes a matrix wiring section for interconnecting the individual electrodes 4 corresponding to the light receiving elements 2 arranged in the same order in all the blocks, and this has a pattern corresponding to the blocks. Six upper layer wiring patterns 7 (equal to the number of light receiving elements in one block) are provided on the pattern of the electrode 4, insulated by an intermediate insulating layer 6, and the intermediate insulating layer 6
In this configuration, the corresponding upper layer wiring pattern 7 and the pattern of the individual electrode 4 are connected by a contact portion 8 penetrating through the contact portion 8 .

Common electrode pads 3b, which are part of the common electrode 3, and individual electrode pads 4b, which correspond to groups of individual electrodes interconnected by the matrix wiring section 5, are alternately arranged along one side of the substrate 1. ing. 4a is an individual electrode lead for connecting the individual electrode pad 4b and the corresponding individual electrode group.

[0006]

[Problem to be Solved by the Invention] However, according to such a configuration, the array of receiving elements is biased toward one side of the substrate.
There were problems such as stray light from the end surface of the substrate easily entering the light receiving element.

That is, in practice, the number of light receiving elements in one block is quite large, about 32, so the area occupied by the matrix wiring section is considerably larger than the area occupied by the common electrode pads and the individual electrode pads. Become. Therefore, in order to effectively utilize the substrate surface, it is necessary to move the light receiving element array to one side of the substrate.

Normally, a plurality of image sensors of this type are manufactured simultaneously on a large-sized unit substrate, and finally individual image sensor substrates are cut out. However, it is difficult to make the cut surface of the image sensor substrate exactly perpendicular to the upper and lower surfaces of the substrate, and the cut surface tends to be inclined to some extent. When using an image sensor, document illumination light is emitted from the bottom surface of the substrate (the surface opposite to the surface on which the light-receiving elements are formed), but if the light-receiving element row is close to the edge of the substrate, the illumination light may be reflected off the slanted edge of the substrate. Original illumination light or other external light tends to enter the light receiving element as stray light.

On the other hand, if an attempt is made to arrange the light receiving element array at the center of the substrate in order to reduce such stray light from the end surface of the substrate, not only will the width of the image sensor substrate increase and the size of the image sensor will increase; Since the number of image sensors obtained from a unit substrate decreases, an increase in the manufacturing cost of image sensors is unavoidable.

The present invention has been made in view of the above-mentioned problems, and provides a close-contact image sensor that prevents stray light from entering a light-receiving element from an end surface of a substrate without increasing the substrate area or manufacturing cost. The purpose is to

[0011]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a contact type image sensor in which light-receiving elements are divided into blocks and driven in a matrix, in which a matrix wiring section is divided into both sides of a row of light-receiving elements. It is provided with the structure of providing.

0012

[Operation] Even when the number of light receiving elements per block is large and the area occupied by the matrix wiring section is large,
By arranging the matrix wiring section separately on both sides of the light-receiving element array as described above, the substrate width remains the same or almost the same as when the matrix wiring section is concentrated on one side.
The light receiving element array can be arranged near the center of the substrate. As a result, the distance between the light-receiving element array and the end face of the substrate increases, making it difficult for stray light from the end face of the substrate to enter the light-receiving elements.

[0013]

[Embodiment] FIG. 1 is a schematic plan view showing the main part configuration of a contact type image sensor according to an embodiment of the present invention, and parts corresponding to the conventional example shown in FIG. 3 are designated with the same or similar numbers. It is being FIG. 2 is a circuit diagram showing the electrical connections of this image sensor.

In FIG. 1, in this image sensor, the light receiving elements 2 are divided into blocks of six consecutive light receiving elements 2 as in the conventional example, but each block is further divided into a first sub-block consisting of four light receiving elements 2 and the rest. It is divided into a second sub-block consisting of two light-receiving elements 2. Then, the common electrodes 3 corresponding to each block are arranged in a staggered manner so that the common electrodes 3 corresponding to each block are alternately positioned on both sides of the row of light receiving elements, and the four light receiving elements 2 belonging to the first sub-block of each block are arranged alternately on both sides of the row of light receiving elements. is connected at one end (upper side in FIG. 1), and connected to the two light receiving elements 2 belonging to the second sub-block at the other end (lower side in FIG. 1).

The individual electrodes 4 corresponding to each light receiving element 2 are also connected to the light receiving element 2 belonging to the first sub-block and the light receiving element 2 belonging to the second sub-block of each block in accordance with the connection between the common electrode 3 and the light receiving element 2. They are arranged in a staggered manner so that they connect at opposite ends.

The matrix wiring section includes a matrix wiring section 5a for matrix connection of the individual electrodes 4 corresponding to the first sub-block light receiving elements 2 of each block, and a matrix wiring section 5a for connecting the individual electrodes 4 corresponding to the second sub-block light receiving elements 2 of each block. It is divided into matrix wiring portions 5b for matrix connection, and each is disposed on both sides of the light receiving element array.

Common electrode pad 3b and individual electrode pad 4b
are arranged along one side of the substrate 1 as in the prior art, and the individual electrode pads 4b are connected to corresponding individual electrode patterns by individual electrode leads 4a as in the prior art. The common electrode lead 3a and the individual electrode lead 4a intersect with the upper wiring pattern 7 of the matrix wiring section 5b, but are insulated by the intermediate insulating layer 6 between them.

As is clear from the above explanation and FIG. 1, in this image sensor, the matrix wiring portions 5a and 5b are provided on both sides of the light receiving element row, so that the number of elements in the light receiving element block can be reduced to a practical level. Even if the number of elements is increased to 32 elements, the board width (board area) is almost the same as with the conventional configuration (a configuration in which the photodetector array is moved to one side of the board).
The light-receiving element array can be placed near the center of the substrate without changing the structure.

In this image sensor, the common electrode has a staggered shape spanning both sides of the light-receiving element array, and the individual electrodes have also been arranged in a staggered manner, but each electrode may have a linear shape similar to the conventional one or a staggered arrangement. It is also possible to set it as an arrangement. However, using a staggered shape or a staggered arrangement has advantages such as being able to reduce wiring intersections.

In addition, in this image sensor, each block is divided into subblocks at a ratio of 2:1 in the number of elements, and the matrix wiring section is divided accordingly, but the number of elements in the block increases to 32 elements. In this case, the division ratio can be brought closer to 1:1. This division ratio is
It is preferable to consider the area occupied by the common electrode pad and the individual electrode pads, and to select such that the light-receiving element array is sufficiently separated from the end surface of the substrate.

[0021]

[Effects of the Invention] As is clear from the above description, the present invention provides a matrix wiring section divided on both sides of the photodetector array, so that the photodetector array can be easily placed near the center of the board without increasing the board area. This has the effect of making it possible to create a close-contact image sensor in which stray light from the edge of the substrate is less likely to enter the light-receiving element at the same manufacturing cost and size as the conventional one. be.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing the configuration of main parts of a contact type image sensor according to an embodiment of the present invention.

[Figure 2] Circuit diagram showing electrical connections of the contact type image sensor

[Fig. 3] A schematic plan view showing the main part configuration of a conventional contact type image sensor.

[Explanation of symbols]

1 Board 2 Photo receiving element 3 Common electrode 3a Common electrode lead 3b Common electrode pad 4 Individual electrodes 4a Individual electrode lead 4b Individual electrode pad 5a, 5b Matrix wiring part 6 Intermediate insulation layer 7 Upper layer wiring pattern 8 Contact part

Claims (1)

[Claims] 1. A plurality of light receiving elements arranged linearly on a substrate, and a common electrode that corresponds to a block consisting of a fixed number of continuous light receiving elements and that is common and continuous to the light receiving elements in the corresponding block. , a matrix wiring section that interconnects individual electrodes corresponding to each of the light receiving elements and connected to the corresponding light receiving elements, and the individual electrodes corresponding to the light receiving elements having the same arrangement order in all the blocks; a common electrode pad connected to a common electrode, and an individual electrode pad connected to a group of individual electrodes interconnected by the matrix wiring, the matrix wiring section being divided into both sides of the array of the light receiving elements; A close-contact image sensor is provided.