JPH02174161A - Image readout device - Google Patents

Abstract

PURPOSE:To shut off unnecessary reflected light which is incident on individual picture elements by using a light-shielding layer and to enhance a resolving power of a photodetector by a method wherein the light-shielding layer is laid between an EL light-emitting element and the photodetector. CONSTITUTION:An EL light-emitting element 4 provided with a metal electrode 44 and a photodetector 2 are arranged and installed via an insulating layer 42; a light-incident window 6 which is used to guide reflected light alpha1 from a manuscript 100 arranged on the side of a transparent electrode 41 of the EL light-emitting element 4 to the photodetector 2 is installed at the metal electrode 44. A light-shielding layer 12 provided with a window part 11 transmitting the reflected light alpha1 from the manuscript 100 facing the photodetector 2 is laid between the EL light-emitting element 4 and the photodetector 2; light alpha2 from parts other than the manuscript 100 corresponding to individual picture elements 21 of the photodetector 2 is shut off by the light-shielding layer 12 in order to prevent the light from being incident on the photodetector 2. Thereby, a resolving power of an image readout operation is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image reading device used in a facsimile, scanner, etc., and particularly relates to the structure of an EL light emitting element for improving resolution.

(Prior Art) Conventionally, facsimile machines, scanners, etc., consist of a fluorescent light source, an image sensor, and an optical system that focuses the reflected light from the original onto the image sensor. 2. Description of the Related Art An image reading device is used that stores signals as electrical signals in a linearly arranged light receiving element array by electrical scanning and outputs the electrical signals in time series.

This image reading device has the disadvantage that it is difficult to miniaturize the device because it uses a rod lens array or the like as an optical system.

Therefore, an ultra-compact image reading device has been proposed that uses an EL light emitting element as a light source and integrates the EL light emitting element and a contact type image sensor.

For example, as shown in FIG. 6 (a>(b)), this image reading device includes a thin substrate 1 made of glass, ceramic, etc., and a light-receiving element array 2 formed of a plurality of pixels 21 on the substrate 1. , a transparent insulating layer 3 formed to cover the light receiving element array 2, and an EL layer disposed on the transparent insulating layer 3.
It is composed of a light emitting element 4.

The EL light emitting element 4 includes a transparent electrode 41. Insulating layer 42° Light emitting layer 43. Insulating layer 42. The metal electrode 44 is sequentially laminated on the transparent substrate 5. The metal electrode 44 has a rectangular, circular, elliptical, etc. light incident window 6 opened corresponding to each pixel 21 of the light receiving element array 2, and the light emitted from the light emitting layer 43 is reflected by the original 100. The configuration is such that the reflected light irradiates the pixels 21.

(Problem to be Solved by the Invention) However, according to the structure of the image reading device described above, the reflected light α1 from the original 100 is reflected on the back surface of the metal electrode 44 at the pixel 21 of the light receiving element array 2. The multiple reflected light β generated by this is irradiated. Therefore, since the pixel 21 accumulates charge for the total amount of light, the electrical signal output from the pixel 21 includes unnecessary light, and the resolution of the light receiving element (MTF
There was a problem that this resulted in a decrease in

The present invention has been made in view of the above circumstances, and provides an image reading device that can integrate an EL light emitting element and a contact type image sensor to achieve miniaturization and improve the resolution of image reading. The purpose is to

(Means for Solving the Problems) The image reading device of the present invention, which solves the problems of the conventional example described above, is characterized by the following configuration.

An EL light emitting element having at least a metal electrode and a light receiving element are disposed with an insulating layer interposed therebetween.

A light entrance window is provided on the metal electrode for guiding reflected light from a document placed on the transparent electrode side of the BL light emitting element to the light receiving element.

A light-shielding layer having a window portion that transmits reflected light from a document facing the light-receiving element is interposed between the EL light-emitting element and the light-receiving element.

(Function) According to the present invention, since the light-shielding layer is interposed between the ELQ optical element and the light-receiving element, the light-shielding layer blocks light from other than the document corresponding to each pixel of the light-receiving element. Prevent it from entering the element.

(Example) An example of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory cross-sectional view of an image reading device according to an embodiment, and parts having the same configuration as those in FIG. 6 are designated by the same reference numerals.

The light receiving element array 2 includes, for example, a plurality of individual electrodes (chrome patterns) corresponding to the pixels 21 and a band-shaped transparent electrode (IT
It is formed of a sandwich structure sensor in which amorphous silicon (a-3t) is sandwiched between amorphous silicon (a-3t) and amorphous silicon (a-3t).

The light emitting element 4 has a light emitting layer 43 made of ZnS:Mn or the like.
are sandwiched between insulating layers 42 made of Y2O, Si, N, BaTLOl, etc., and these are further layered with ITO, In, O, etc.
It is constructed by being sandwiched between a transparent electrode 41 made of SnO, etc. and an opaque metal electrode 44 made of metal such as aluminum.

The light emitted from the light emitting layer 43 is applied to the metal electrode 44.
A rectangular light entrance window 6 having an area smaller than the pixel is opened above each pixel 21 of the light receiving element array 2 so that the reflected light irradiates the light receiving element array 2.

A transparent glass plate 10 is inserted between the light-receiving element array 2 and the EL light-emitting element 4, and a light-shielding layer 1 is provided on the surface of the transparent glass plate 10, which has a window 11 of the same size as the light entrance window 6.
2 is formed. The window portions 11 are formed to correspond to the light entrance windows 6, respectively, and are arranged so that the light entrance windows 6 are located directly above the window portions 11. This light shielding layer 12 is intended to prevent reflected light from sources other than the original located directly above the light entrance window 6 and light emitted from the light emitting layer 43 from being guided directly to the pixels 21 .

A transparent substrate 5 is disposed on the EL light emitting element 4 to prevent the EL light emitting element 4 from being worn out due to direct contact between the EL light emitting element 4 and the surface of the original 100 read by the image reading device. . Alternatively, the EL light emitting element 4 may be formed on the transparent substrate 5, and the transparent substrate 5 on which the EL light emitting element is formed may be placed on the transparent glass plate 10.

When a driving signal for emitting light from the EL light-emitting element is applied between the metal electrode 44 and the transparent electrode 41, the light-emitting layer 43 in the area sandwiched between these picture electrodes emits light, and the light-emitting layer 43 in the area directly above the light entrance window 6 emits light. Layer 43 does not emit light.

The light emitted upward from the light emitting layer 43 is reflected by the original 100, and the reflected light α irradiates each pixel 21 from the light entrance window 6, but the multiple reflected light β as shown in FIG. The light does not reach the back surface of the metal electrode 44 and therefore does not irradiate each pixel 21. In addition, when paying attention to the pixel 21a in FIG. 1, the light entrance window 6 directly above it
The reflected light α1 from the document surface 100 passing through a is reflected by the pixel 2
1a, but reflected light (for example, reflected light α2) from an adjacent document surface is blocked by the light shielding layer 12.

In this embodiment, the light shielding layer 12 is the EL light emitting element 4ff of the transparent glass plate 10! ! Although it is formed on the light-receiving element array 2 side, it is also possible to form it on both sides of the transparent glass plate 10 to further block unnecessary reflected light from the document surface.

Furthermore, in order to effectively block reflected light from the adjacent document surface from irradiating the pixels 21 by interposing only one layer of the light-shielding layer 12 between the light-receiving element array 2 and the EL light-emitting elements 4, it is necessary to The effect differs depending on where the light shielding layer 12 is placed between the array 2 and the EL light emitting elements 4. That is, when the light receiving element array 2 and the EL light emitting element 4 are inserted at a position of 2/3 of the distance between them toward the EL light emitting element 4 (Fig. 4), when the light shielding layer 12 is not interposed (Fig. 3), In comparison, reflected light α2. α3. α4. Since it is possible to block the reflected light α5° and α7, and especially the reflected light α2 having the largest amount of light passing through the near-light entrance window 6b, it is possible to effectively block unnecessary reflected light from the adjacent document surface.

Therefore, each light receiving element allows reflected light from the document surface to be read to be incident on each light receiving element, and also prevents light from other than the corresponding document onto each pixel 21 of the light receiving element from entering the light shielding layer 1.
2 effectively blocks the light from entering the light receiving element, so it is possible to improve the resolution of the light receiving element.

Next, a method for manufacturing the above-described image reading device will be described.

This image reading device includes a light receiving element array 2. The EL light emitting elements 4 are manufactured separately, and finally they are bonded together.

That is, a light receiving element array 2 is formed on a substrate 1 made of glass, ceramic, or the like. The light receiving element array 2 is
For example, a chromium film is deposited on the substrate 1 and patterned by photolithography to form a plurality of individual electrodes, and amorphous silicon is deposited to cover the individual electrodes to form a band-shaped photoconductive layer. A band-shaped transparent electrode is formed by depositing indium tin oxide on the layer.

ITO is placed on a transparent substrate 5 made of a glass plate or the like.

I n20. , SnO, etc., by sputtering or the like to form a transparent electrode 41, and then Y on the transparent electrode 41.

0, , St, N, , BaTi0. etc. to form an insulating layer 4.
ZnS is formed on the insulating layer 42 by sputtering or the like.
A strip-shaped light emitting layer 43 is formed by depositing Mn or the like, an insulating layer 42 similar to the above is formed again, a metal such as aluminum is vapor deposited on the insulating layer 42, and patterned by photolithography to form a light incident window 6. EL is formed by forming a metal electrode 41 having
A light emitting element 4 is produced.

Next, a light-shielding Jlli (Brewer 5cie) is placed on the insulating transparent glass plate 10 to cover the entire surface.
DARC (manufactured by nce) is coated or deposited. Then, the light shielding film is etched using a mask having an opening of the same size as the mask used to form the entrance window 6 until the transparent glass plate 10 is exposed, thereby forming a light shielding layer 12 having a window 11. do.

A transparent glass plate 10 is placed between the substrate 1 on which the light receiving element array 2 is formed and the transparent substrate 5 on which the EL light emitting elements 4 are formed, and the pixels 21 and the window portion 11 . The window portion 11 and the entrance window 6 are bonded using an adhesive 9 so as to correspond to each other.

FIG. 5 shows another embodiment of the present invention, in which the light shielding layer 12
is formed continuously on the metal electrode 44 of the EL light emitting element 4. In this case, aluminum and a light-shielding film (Br
According to the zero-layer structure, the electrodes having the entrance window 6 and the light-shielding layer 12 having the window portion 11 can be formed by successively depositing DARC> manufactured by Wer 5science and etching each using the same mask. It is possible to prevent the pixels 21 from being irradiated with multiple reflected light.

Further, in the manufacturing process of the light receiving element array 2, an insulating layer may be formed on the common electrode, and the light shielding layer 12 having the window portion 11 may be formed on this insulating layer.

If the light shielding layer 12 is formed continuously on the F and L light emitting elements 4 and the light receiving element array 2, the light receiving element array 2 and the EL light emitting elements 4
The transparent glass plate 10 between the light emitting element 4 and the light receiving element array 2 is removed by sandwiching the passivation film 30 between the light emitting element 4 and the light receiving element array 2.
to join.

(Effects of the Invention) According to the present invention, since the light-shielding layer is interposed between the EL light-emitting element and the light-receiving element, unnecessary reflected light that enters each pixel can be blocked by the light-shielding layer, and the light-receiving element It is possible to improve the resolution of

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view of an image reading device according to an embodiment of the present invention, FIG. 2 is an explanatory plan view of a light shielding layer formed on a transparent glass plate, and FIGS. 3 and 4 are irradiation of reflected light from the surface of a document. FIG. 5 is an explanatory cross-sectional view showing another embodiment of the present invention. FIG. FIG. 2(b) is an explanatory cross-sectional view of the same as above. 1... Substrate 2... Light receiving element array 21... Pixel 4... EL light emitting element 5... Transparent substrate 6... ...Light entrance window 10...Transparent glass plate 11...Window section 12...Light blocking layer Figure 1 Figure 3 Figure 4 Procedure amendment (method) % formula % Indication of the case Patent application No. 326271 of 1988, Title of the invention Image reading device Edit the "Brief explanation" column. Figure 6 (a) (b)

Claims (1)

[Scope of Claims] An EL light emitting element having at least a metal electrode and a light receiving element are disposed with an insulating layer interposed therebetween, and light for guiding reflected light from a document placed on the side of the EL light emitting element to the light receiving element. In an image reading device in which an entrance window is provided on a metal electrode, a light-shielding layer having a window portion that transmits reflected light from a document facing the light-receiving element is interposed between the EL light-emitting element and the light-receiving element. An image reading device characterized by: