JPH0758766B2 - Perfect contact image sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a perfect contact image sensor for reading an image at an actual size, in particular, a rod lens for image formation is omitted to integrate a light source and a light receiving element. The present invention relates to a perfect contact image sensor.

(Prior Art) In the past, as a technology in such a field, Nikkei Mechanical (1986-12-1) Nikkei McGraw-Hill, Inc. "For a trump card for miniaturization of contact type image sensor OA equipment with short optical path" P.71-78 Some were mentioned. The configuration will be described below with reference to the drawings.

FIG. 2 is a diagram showing a configuration example of a conventional contact image sensor.

This contact image sensor is composed of a light emitting diode (hereinafter referred to as LED) array 2 for irradiating a document 1, a rod lens array 3 for image formation, and a light receiving element 4 for optical / electrical conversion. . When the document 1 is irradiated with the light emitted from the LED array 2, the image of the document 1 is formed on the light receiving element 4 through the rod lens array 3, converted into an electric signal by the light receiving element 4, and read.

In this type of contact image sensor, since the image of the original 1 is read at the original size using the rod lens array 3, the optical path is significantly shortened as compared with an image sensor using a reduction optical system, and a copier or facsimile machine is used. It is possible to reduce the size of the image reading device such as.

However, since the rod lens array 3 is used, it is not sufficiently satisfactory in terms of size and weight reduction. Therefore, a perfect contact type image sensor without the rod lens array 3 has been proposed.

FIG. 3 is a diagram showing a configuration example of a conventional perfect contact image sensor.

The perfect contact type image sensor includes an LED array 10 and a sensor body 20. The sensor body 20 has a glass substrate 21, the electrode 22, on the bottom surface of the glass substrate 21,
A light receiving element 23 made of amorphous silicon (hereinafter referred to as a-Si), a transparent electrode 24, and an electrode 25 are formed in a laminated state. A window 26 for passing light is provided in the center of the light receiving elements 23 and the like, and these light receiving elements 23 and the like are covered by a transparent protective layer 27.
Is covered with. An original 28 is placed under the transparent protective layer 27. Then, by the LED array 10, the glass substrate 2
1. When a document 28 is illuminated through the window 26 and the transparent protective layer 27, the image of the document 28 passes through the transparent protective layer 27 and the light receiving element.
It is converted into an electric signal at 23.

In this perfect contact type image sensor, since the rod lens array is omitted, the size and weight can be reduced, and there is no light amount loss in the rod lens array.
The output of 23 also becomes large and the signal-to-noise ratio (S / N ratio) improves.

(Problems to be solved by the invention) However, in the perfect contact type image sensor of FIG. 3, since the LED array 10 as a light source and the sensor body 20 on the light receiving element 23 side are individually configured, the size is small. However, there was a limit to weight reduction. Moreover, when assembling the image sensor as a unit, it is necessary to adjust the mounting positions of the LED array 10 and the sensor body 20, and this adjustment is complicated, and if the adjustment is insufficient, Since the amount of incident light is reduced and the reading accuracy is lowered, it is difficult to solve them.

The present invention provides a complete contact type image sensor that solves the problems of the above-mentioned conventional technology in that there is a limit to the reduction in size and weight and the complexity of adjusting the mounting position between the light source and the sensor body. To do.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a perfect contact type image sensor which irradiates light to electrically read an image at a full scale, in which at least the image sensor is mounted on an element. A substrate, and a film-like light emitting element formed on the substrate,
On the common electrode, there is a light-shielding common electrode having a first window for passing the emitted light of the light-emitting element and covering the light-emitting element, and a second window located on the first window. The formed film-shaped light receiving element and the light emitting element, the common electrode, and the light-transmitting protective film deposited on the light receiving element.

(Operation) According to the present invention, since the perfect contact type image sensor is configured as described above, the light emitting element and the light receiving element formed on the same substrate function to improve the size and weight reduction by integration. In addition, the positional relationship between the two can be set with high accuracy at the stage of the manufacturing process, and the position adjustment at the time of assembling work becomes unnecessary. Therefore, the above problems can be eliminated.

(Embodiment) FIGS. 1 (1) and 1 (2) show an embodiment of the present invention. FIG. 1 (1) is a schematic plan view of one dot of a perfect contact image sensor, and FIG. 2) is a sectional view taken along the line AA.

This perfect contact image sensor is a glass plate, resin plate,
An insulative substrate 30 such as a metal plate covered with an insulation is provided, and an individual electrode 31 for a light emitting element made of chromium or the like is provided on the substrate 30.
Are formed.

A film-shaped light emitting element 32 for converting electricity into light is formed on the individual electrode 31. The light emitting element 32 has a structure in which a light emitting layer 32a made of zinc sulfide, manganese (ZnS: Mn) or the like is sandwiched by insulating films 32b and 32c.
After the formation of 1, the insulating film 32b, the light emitting layer 32a and the insulating film 32c
Are continuously or separately formed by plasma CVD (chemical vapor deposition), vapor deposition, sputtering or the like.

On the light emitting element 32, a light shielding common electrode 33 is formed to cover the light emitting element 32, and on the light emitting element 32, a film of a hydrogenated amorphous silicon (a-Si: H) or the like for converting light into electricity is formed. The light receiving element 34 is formed by plasma CVD, electron cyclotron resonance (hereinafter referred to as ECR) CVD, photo CVD or the like. The common electrode 33 serves as a common electrode for both the light emitting element 32 and the light receiving element 34.
Has a first window 33a for passing the light emitted from the light emitting element 32.
Is opened, and the second window 34a faces the light receiving element 34
Is also formed.

On the light receiving element 34, a translucent individual electrode 35 for the light receiving element made of indium tin oxide or the like is formed. The individual electrode 35 has a third window 35a at a position facing the second window 34a.
Are formed. When the individual electrode 35 is brought into contact with a part of the light receiving element 34, the third window 35a may not be formed.
On the light emitting element 32, the light receiving element 34, the individual electrode 35, etc.,
A translucent insulating protective film 36 made of polyimide resin or the like is applied to protect them. Since the first, second, and third windows 33a, 34a, 35a are provided, a recess is formed in the center of the protective film 36, but the recess may be removed. The original 37 is set so as to face the protective film 36.

Next, the operation will be described.

First, the common electrode 33 is connected to the ground so as to be used for the light emitting element 32 and the light receiving element 34, and a positive voltage is applied to the light emitting element individual electrode 31, and a negative voltage is applied to the light receiving element individual electrode 35. Apply. Then, the light emitting element 32 emits light, and the emitted light irradiates the document 37 through the first, second, and third windows 33a, 34a, 35a as shown by arrows in FIG. 1 (2). Manuscript 37
The image of is converted into an electric signal by the light receiving element 34 through the protective film 36 and read.

The present embodiment has the following advantages.

(A) Since the light emitting element 32 and the light receiving element 34 are integrally formed on the substrate 30, the size and weight of the entire sensor unit can be significantly improved.

(B) Since the light emitting element 32 and the light receiving element 34 are formed on the same substrate 30, the light emitting element 32 is formed during the manufacturing process.
Thus, the light receiving element 34 can be accurately formed at an accurate arrangement position.
Therefore, it is possible to omit the complicated work of position adjustment at the time of assembling work of the light source and the light receiving element as in the prior art, simplify the manufacturing process, and improve the optical axis matching accuracy.
The reliability can be increased.

(C) Since the distance between the light emitting element 32 and the original 37 becomes short,
Incident light on the original 37 becomes stronger, and the S / N is significantly improved.
Moreover, since the light emitting element 32 is covered with the common electrode 33 and the light is emitted through the first window 33a of the common electrode 33, the light quantity loss is small, the light emitting efficiency is high, and the power consumption is low. Can be expected.

(D) Since the common electrode 33 is also used as the light emitting element 32 and the light receiving element 34, the number of electrodes can be reduced.

The present invention is not limited to the illustrated embodiment, and various modifications can be made. The following are examples of such modifications.

(I) The light emitting element 32 and the light receiving element 34 can be formed of various materials other than those illustrated. For example, the light emitting element 32 is configured by a three-layer pin junction or an nip junction made of amorphous silicon carbide (a-SiC).
They may be formed on the substrate 30 by plasma CVD, ECR / CVD, photo CVD, vapor deposition, sputtering or the like.

(Iii) The individual electrodes 31, 35 and the common electrode 33 are the light emitting elements 32.
Also, the light receiving element 34 can be deformed into various arrangements and shapes according to changes in the arrangement and shape of the light receiving elements 34.

(Effects of the Invention) As described in detail above, according to the present invention, the light emitting element and the light receiving element are integrally formed on the substrate.
The size and weight of the entire device can be significantly improved, and the light emitting element and the light receiving element can be accurately formed at appropriate arrangement positions, thereby simplifying the manufacturing process and improving reliability.
Since the distance between the light emitting element and the manuscript is shortened, the S / N ratio is remarkably improved. Moreover, since the light of the light emitting element is emitted through the first window of the common electrode, the emission efficiency is high,
Low power consumption can also be expected. Furthermore, since the common electrode is also used as the light emitting element and the light receiving element, the effect of reducing the number of electrodes can be expected.

[Brief description of drawings]

1 (1) and 1 (2) show an embodiment of the present invention.
FIG. 1A is a schematic plan view of the perfect contact image sensor, FIG. 2B is a sectional view taken along the line AA of FIG. 1A, and FIG. 2 is a configuration diagram of a conventional contact image sensor. FIG. 3 is a block diagram of a conventional perfect contact type image sensor. 30 …… Substrate, 31,35 …… Individual electrode, 32 …… Light emitting element, 33
...... Common electrodes, 33a, 34a, 35a …… First, second and third windows, 34
…… Light receiving element, 36 …… Protective film, 37 …… Document.

Claims (1)

[Claims] 1. A perfect contact type image sensor for irradiating light to electrically read an image at a full scale, and a substrate for mounting an element, and a film-like light emission for electrical / optical conversion formed on the substrate. An element; a light-shielding common electrode having a first window for allowing the light emitted from the light-emitting element to pass therethrough; and a second window located on the first window. A light receiving element in the form of a film for light-to-electricity conversion formed on the electrode; and a light-transmitting protective film deposited on the light emitting element, the common electrode and the light receiving element. Perfect contact image sensor.