JPS58127463A - Close contact type image sensor - Google Patents

Abstract

PURPOSE:To prevent a transmission original from being damaged and scattering of light when the original is read, by forming a transparent protective layer with a glass plate and a transparent and highly hard thin film formed on the glass plate. CONSTITUTION:The transmission original 1 is pressed with a paper feed roller 13 on a transparent protection layer 11 arranged on the surface of a close contact type image sensor and carried toward the A. The luminous flux 12 from the light source illuminates the original 1 athrough a transparent base 5, an illumination window 6, and the layer 11, and the reflected light is caught on an island 8 of a photo-conductor and photo-electric-converted. The film 11 consists of the thin plate glass 15 and an aluminum oxide thin film 14 formed on the surface. Since the hardness of the thin film 14 is as high as 9 in Mohs' hardness, the surface is hardly subject to scratch and the thin plate glass 15 is protected from damage completely.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for arranging a plurality of optical sensors on a transparent substrate in a size corresponding to, for example, a facsimile transmission document, and transmitting an original document placed on the transparent substrate. Lighted from below,
The present invention relates to a contact image sensor that receives reflected light with an optical sensor array.

Conventionally, in the case of a reading system for a transmitted document such as a facsimile machine, as shown in FIG. A close-contact image sensor 4 whose dimensions are approximately the same as the width of the transmitted original 10 is sent through a light guide system 3 such as
and obtained time-series electrical signals. In this case, it is difficult to align the light guide system 3 and the contact image sensor 4,
Further, there was a drawback that the light guiding system 3 was expensive.

Therefore, as a method to resolve the above-mentioned drawbacks, a method has been proposed in which the sensor and the transmitted original are brought into close contact with each other and the original is directly read without using the light guide system 3. In this method, for example, as shown in FIG. 2, which is a cross-sectional view, and FIG. A light shielding layer 7 is formed, on which a row of photoconductor islands 8, a transparent electrode 9. It has a structure in which a metal electrode 10 is provided and the entire structure is covered with a transparent protective layer 11. Note that 12 is a luminous flux from a light source (not shown), and 1s is a paper feed roller.

In FIG. 2, the transmission document 1 is pressed against the transparent protective layer 11 disposed on the surface of the contact image sensor by the paper feed roller 13, and is transported in the direction indicated by arrow A in the figure. A regular scan is performed.

A light beam 12 from a light source such as a fluorescent lamp (not shown) is transmitted to a transparent substrate 5. The transmitted original 1 passes through the illumination window 6 and the transparent fuzzy layer 11.
The reflected light is captured by the photoconductor island 8 and photoelectrically converted.

At this time, the photoconductor islands 8 are arranged in a one-dimensional row in the direction perpendicular to the plane of the paper in FIG. A scan is performed. The transparent protective layer 11 serves to prevent the sending document 1 from directly contacting the photoconductor island 8, and also allows the reflected light from the beam 12 from the sending document 1 to efficiently enter the photoconductor island 8. It plays the role of maintaining a constant distance between the photoconductor island 8 and the transmission document 1. Transparent protection Ji
11 needs to have a thickness comparable to the resolution, that is, the pitch of the islands 8 of the photoconductor, from the viewpoint of the conductive efficiency. For example, in the case of resolution of 8 lines and 10, a thickness of about 100 μm is required. For this purpose, at least the photoconductor island 8 and the illumination window 6 are bonded with a transparent adhesive to form a thin glass plate serving as the transparent protective layer 11.
It is made of K which is glued so as to cover it.

However, as shown in FIG. 2, the above-mentioned contact type sensor has a structure in which the transmitted document 1 directly rubs the surface of the transparent protective layer 110, so it is difficult to detect minute dust or metal particles contained in the copied paper. Transparent protective layer 1 with powder etc.
The surface of the thin glass plate 1 is easily scratched, and such scratches cause scattered light that interferes with the reading of the transmitted document 1, which has disadvantages such as significantly impairing the performance of the contact type image sensor. there were.

The present invention was made to eliminate the above-mentioned drawbacks, and provides a contact type image cell in which a transparent protective layer is composed of a glass plate and a transparent and highly hard thin film formed on the glass plate. It is. Hereinafter, the present invention will be described in detail based on the drawings.

FIG. 4 shows an embodiment of the present invention, in which the transparent protective layer 11 includes a thin glass 15 and an oxidized film formed on the surface thereof.
(Al, pseudo) thin film 14. The full oxidized ξ thin film 14 is formed by, for example, pasting the thin glass 15 with an adhesive and then depositing a thin film of several μm on the surface by reactive high frequency sputtering or electron beam evaporation. The aluminum oxide thin film 14 thus formed has a high hardness of about 9 on the Mohs scale, and the Mohs hardness of glass is 4.
-7, it is extremely hard. Therefore, the surface of the oxidized Fulumi thin film 140 is hardly scratched, and the thin glass 15 underneath is also completely protected from scratches. Therefore, by configuring the transparent protective layer 11 in this manner, it is possible to obtain a contact type image sensor whose performance is unlikely to deteriorate due to scratches on the surface of the °C transparent protective layer 11 during long-term use.

In the above embodiment, the thin film formed on the surface of the thin glass 15 is the oxidized full ξ thin film 14, but other materials such as silicon nitride, tantalum oxide, silicon carbide, etc. can also be used.

As explained above, in this invention, the transparent protective layer of a contact type image sensor is formed by depositing a thin glass and a full oxidized ξ thin film formed on the six sides of the glass, so that the surface of the transparent protective layer has a high hardness. This has the advantage that a contact type image sensor with good performance can be obtained because no scratches occur even when the surface of the transmitted document is rubbed, and therefore reflected light that interferes with the light beam reading the document is not scattered.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view showing a conventional transmission document reading system, Fig. 2 is a sectional view of a conventional direct reading sensor, Fig. 3 is an enlarged plan view of Fig. 2, and Fig. 4 is an example of the present invention. It is a sectional view showing an example. In the figure, 1 is a transmission document, 5 is a transparent substrate, 6 is an illumination window, and T
is a photosensitive layer, wealth is a photoconductor island, 9 is a transparent electrode, 10 is a metal electrode, 11 is a transparent protective layer, 12 is a luminous flux, 13 is a paper feed p-ra, 14 is an aluminum oxide thin film, 15 is a thin plate It's glass. Figure 1 Figure 3 8 8 888 Figure 4

Claims (1)

[Claims] An optically transparent substrate, a light-shielding layer that is optically opaque and an electrically poor conductor formed on this substrate, a transparent window for illumination made in this light-shielding layer, and a light-shielding layer in the vicinity of this. In a close-contact image sensor, the contact image sensor includes a photoelectric conversion element array formed on a glass plate, and a transparent protective layer arranged on at least the transparent window and the photoelectric conversion element array. A contact image sensor characterized by comprising K and a transparent and highly hard thin film formed on a plate.