JPH03185864A - Image reading device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an image reading device. In particular, the present invention relates to a fully contact type 1x image reading device, and particularly to a fully contact type 1x image reading device of a type in which the width of the sensor substrate is extremely narrow.

[Prior art]

One way to reduce the cost of full-size sensors is to make the substrate narrower. This is because by manufacturing a large number of same-size sensor substrates at once using a large-area substrate, it is possible to reduce the manufacturing equipment cost and material cost per unit. The narrower the inside of the board, the lower the board cost I per board.
~ decreases.

However, in particular, one image signal is read with the image in close contact with the sensor surface. In the case of a so-called full-contact type 1-magnification sensor, an 1-magnification imaging element is not required and the cost can be reduced. Since it becomes difficult to maintain the signal, the conventional technique has a problem in that the S/N ratio decreases. FIG. 1 shows a conventional example.

A light-shielding layer (not shown) having a photoelectric conversion element and a window through which incident light passes on a transparent substrate, and a same-size sensor substrate having a transparent protective layer are usually held by a light-shielding holding member made of metal, The light-shielding holding member has a slit through which incident light can pass. This is not a problem if the substrate width is sufficiently wide as shown in Figure 1A, but as the substrate width becomes narrower as shown in Figure 1B, the slit width must also become narrower in order to securely hold the substrate. I don't get it. As the slit width becomes narrower, the amount of incident light decreases and the signal output S decreases, resulting in a decrease in S/N. FIG. 2 shows the relationship between the signal output S and the slit width. When the slit width is 1+m+ or more.

The signal output S hardly changes, but sharply decreases below 1 circle, and at 0.5 mn, S decreases to 1/2.

〔the purpose〕

The purpose of the present invention is to solve the above-mentioned problems, and to propose a mounting method that can securely hold even a same-size sensor with a narrow board width and prevent S/N deterioration. It is.

〔composition〕

The present invention provides a transparent substrate, a light blocking layer formed on the transparent substrate having a lighting window, a sensor substrate having at least an array of photoelectric conversion elements formed on the light blocking layer, and a holder for supporting the sensor substrate. The present invention relates to an image reading device comprising a member, wherein necessary portions of the holding member are made of a transparent material.

If the photoelectric conversion element directly contacts an image, for example, a document, the element will be damaged, so it is preferable that there is some sort of spacing layer between the element and the image.

The spacing layer may be a mere space, but it may be 5L-C, 5i-N,
A transparent thin film such as 5L-0 or microcrystalline C or a transparent thin plate material such as quartz or plastic may be used. In the case of a thin film, a normal film forming method may be used, and in the case of a thin plate material, a transparent adhesive may be used.

A detailed explanation will be given below based on FIG.

The transparent substrate 1 is made of quartz, glass such as virex, plastics, or the like. A light-shielding layer 2 made of Cr, An, etc. is formed on the transparent substrate 1 to a thickness of 0.1 μm to 0.5 μm by vacuum evaporation, sputtering, etc., and then a light shielding layer 2 of approximately the same number as the number of reading elements is formed. A window 4 is formed by an etching method (FIG. 5). Thereafter, a transparent insulating film is formed on the entire surface in order to prevent short circuit between the light shielding layer 2 and other electrode materials. The transparent insulating film is 5i-N.

5i-0, 5i-C, microcrystalline C, etc. formed by CVD or the like are used. What is the film thickness?

0.5 to 3 μm is suitable. Thereafter, as shown in FIG. 5, a photoelectric conversion element 3 is formed as an image reading element at a position having a certain distance from the lighting window 4. A film mainly made of amorphous silicon with electrodes provided above and below is preferably used, and is microfabricated through film formation by conventional CVD and etching by photolithography. Note that it is also possible to use a light shielding layer as the lower electrode of the photoelectric conversion element 3.

After the image reading device is formed as described above, a transparent wear-resistant film with a thickness of 5 to 50 μm, such as 5i-C, 5L-N, 5i-0° microcrystalline C, etc., is used as the protective layer 5. A film is formed on the entire surface by CVD method, or a film is formed with a thickness of 30 to 70 μm.
The sensor substrate process is completed by gluing a thin glass sheet with a thickness of .

Next, the sensor substrate thus obtained is adhered onto the transparent holding member 7 (FIGS. 3 and 4).

The transparent holding member and the transparent adhesive preferably have a refractive index (1.4 to 1.5) comparable to that of the transparent substrate.

Particularly desirable materials for the transparent holding member are glass such as quartz, Pyrex, and plastics.

Further, in the present invention, as shown in FIG. 4, it is preferable to shield the holding member from light except for the portion where light enters and the surface on the transparent substrate on which the photosensitive element is mounted. As a light-shielding means, methods such as holding with a light-shielding holding member such as a metal material such as AQ or SUS, burying in a light-shielding filler, applying a light-shielding adhesive, or a combination thereof are used. A light-shielding holding member 6 is obtained.

〔effect〕

The above-mentioned configuration makes it possible to secure a light path for the sensor board, making it possible to securely hold the sensor board even when the sensor board width is narrow, making it easy to attach the unit externally, and using a transparent holding member. Since a sufficient amount of incident light can be ensured, the signal output S will not decrease, and stray light from the outside can also be blocked, making it possible to provide a fully contact type 1x sensor with no decrease in S/N.

[Brief explanation of drawings]

1A and 1B are cross-sectional views of conventional image reading devices. FIG. 1A shows a case where the sensor board is wide, and FIG. 1B shows a case where the sensor board is narrow. show. FIG. 2 is a graph showing how the size of the slit width in FIG. 1 affects the signal output (relative value). FIG. 3 is a sectional view showing an example of the image reading bag device of the present invention, and FIG. 4 is a sectional view showing a modified example of the image reading device of the present invention. FIG. 5 shows a top view of the image reading device of the present invention. 1... Transparent substrate 2... Light blocking layer 3... Photoelectric conversion element 4... Lighting window 5... Transparent protective layer 7... Transparent holding member 9... Slit 6... Light blocking property Holding member 8...Transparent adhesive layer 11...Document figure slit @ (mml Figure 4 Figure 5

Claims (1)

[Claims] 1. A transparent substrate, a light-shielding layer having a lighting window formed on the transparent substrate, a sensor substrate having at least an array of photoelectric conversion elements formed on the light-shielding layer, and a holding member for supporting the sensor substrate. An image reading device characterized in that necessary portions of the holding member are made of a transparent material.