JPS62264658A - Contact-type image sensor - Google Patents

Abstract

PURPOSE:To obtain a contact-type image sensor reading a copy with high resolution, by providing a light-receiving element in a recessed part of a supporting body and by providing a contact element with the copy outside the indented portion. CONSTITUTION:A rectangular recessed part 33 is provided in a glass plate 31 perpendicularly to a paper surface, and a light-receiving element 13 is provided in about half of the width of the bottom surface of said portion so that it is parallel to the longitudinal direction of the portion. The remaining portion of the bottom surface is used for a window 35 for introducing the light from a light source 21. The light-receiving element 13 is constructed by superposing a first electrode 37 serving also as a light- intercepting layer, an a-Si:H light-receiving layer 39 and a second electrode 41 being transparent and isolated from the electrode 37 sequentially from the bottom surface of the recessed part 33, and is covered with a surface protective layer 43. A copy 17 contacts at the peripheral portion 45 outside the indented portion 33. According to this construction, a light emitted from the light source 21 passes through the window of the substrate 31 and falls on the copy 17, and it is reflected therefrom, reaches the light-receiving element 13 and is converted thereby into an electric signal. Thus, the copy can be read by a simple structure and with high resolution. The recessed part needs only to be several mum to several tens of mum deep.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image sensor, and particularly to a contact type image sensor for reading a document at the same magnification (1:1).

(Prior Art) Conventionally, an image sensor has been proposed that is incorporated into a device such as a facsimile machine or an image scanner, and is used to scan a document. Since such a contact type image sensor does not require a reduction optical system, it has the feature that the device can be made smaller. This contact type image sensor includes a large number of light-receiving sections for receiving reflected light from a document, arranged in an array so as to have the same dimension as the width of the document, for example. Further, research and development is being conducted to use hydrogenated amorphous silicon, which can be manufactured in a large area by a low-temperature process (at a temperature of 200 to 300° C.), for these light-receiving parts.

In such a close-contact image sensor, it is necessary to place the document and the light receiving section in close contact in order to read the document with high resolution. Since the document must be read by receiving light from the light source, a method for irradiating (injecting) the light from the light source onto the document is important.Hereinafter, this method will be explained with reference to the drawings. .

The cabinet 30 is a schematic diagram of a plastic image sensor in the 1F hall, and shows an outline of a document reading device using this image sensor. A rod lens array 19 having a height of, for example, about 7 to 8 mm is provided between an image sensor 15 having a light receiving section 13 on a support 11 and an original 17. Note that gaps are provided between the rod lens array 19, the light receiving section 13, and the original 17 for light convergence. Further, for example, a light source 21 for irradiating light onto the original is provided near the rod lens array 19.
is provided. Therefore, according to this device, the original 1
7 information can be guided to the light receiving section 13 on a one-to-one basis.

FIG. 4 is an explanatory diagram of another example of a conventional contact type image sensor. In the case of this image sensor, a window 23 for introducing light is provided in the center of the light receiving section 13, and a support l
! The original 21 is irradiated with light from a light source 21 provided on the side opposite to the side on which the light receiving section 13 is provided through this window 23 . Furthermore, a light-transmitting insulating film with a thickness of several μm as shown by 25 in FIG. The amount of reflected light 1 from the document received by the light receiving section is increased by maintaining the distance .

(Problems to be Solved by the Invention) However, a conventional contact type image sensor array using a rod lens array has a problem in that the size of the contact type image sensor array becomes large due to the provision of the rod lens array. There was. Furthermore, there is a problem in that the contact type image sensor becomes more expensive due to the use of this rod lens array.

In addition, in the case of a conventional contact image sensor having a structure in which a light receiving part has a window for introducing light from a light source, a complicated manufacturing process for forming the window is required in the manufacturing process of this image sensor, and a window is required to form the window. There is a problem in that it is necessary to perform manufacturing while aligning the light receiving section and the light receiving section with high precision. Therefore, this causes an increase in manufacturing cost and a decrease in manufacturing yield. Furthermore, there is a problem in that it requires a step of forming an insulating film on the light receiving section to increase the amount of reflected light.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned problems and provide a contact image sensor that can read a document with high resolution even if it has a simple structure.

(Means for Solving the Problems) In order to achieve this object, the present invention provides a contact image sensor having a light receiving section on a support for receiving reflected light from a document, as described above. The present invention is characterized in that the light-receiving section is provided in a recess provided in the support described above, and a contact portion that comes into contact with the original is provided in a portion of the support outside the recess.

Note that the light source for irradiating the original can be constructed by, for example, a transparent support and provided on the opposite side of the support from the side that contacts the original. in this case,
The light from this light source passes through the transparent support and illuminates the original.

Alternatively, a light emitting section may be formed in the concave portion of the support body adjacent to the light receiving section, and this light emitting section may be used as a light source for reading the document.

(Function) According to such a configuration, the document is supported by the contact portion of the support portion outside the recess. Furthermore, since the light-receiving section is provided inside the recess, there is a gap between the document surface and the upper surface of the light-receiving section, which is large enough to receive sufficient reflected light from the document, and which allows for high-resolution reading. A gap as narrow as possible is formed.

(Example) Hereinafter, an example of the present invention will be described with reference to FIG. 1 and FIG. 71g2. It should be noted that these drawings are only schematic illustrations to the extent that the present invention can be understood, and the dimensions, shapes, and arrangement relationships of each component are not limited to the illustrated examples. In each figure, the same components are designated by the same reference numerals. In addition, the same components as in the prior art are denoted by the same reference numerals.

FIG. 1 is a sectional view showing a contact type image sensor of the present invention. Note that, in order to avoid complicating the drawing in FIG. 1, hatching indicating the cross section is omitted.

In FIG. 1, reference numeral 31 denotes a support, and in this embodiment, the support 31 is made of a transparent insulating substrate such as glass. In the case of this embodiment, an elongated recess 33 is provided on the side of the transparent insulating substrate 31 that is in close contact with the original 17 in a direction parallel to a direction perpendicular to the plane of the paper. Furthermore, in this embodiment, the reflected light from the original is received on the area on the inner bottom surface of the recess 33, which is approximately half the area in the width direction of the recess 33 and parallel to the longitudinal direction of the recess 33. A large number of light receiving sections 13 are provided in an array for reading the information. Further, the remaining area of the inner bottom surface of the recess 33 is configured to function as a window area 35 for introducing light from the light source 21 provided on the opposite side of the transparent insulating substrate 31 from the original 17, for example. It is.

It should be noted that these light-receiving parts 13 include a first electrode 37 which also serves as one electrode and a light-shielding layer, which are provided sequentially from the bottom side of the recess 33, a light-receiving layer 39 made of hydrogenated amorphous silicon, for example, The second electrode 41 is electrically separated from the first electrode and is made of a transparent conductive film. Further, in FIG. 1, reference numeral 43 indicates a surface protection insulating layer for protecting the light receiving section 13. Further, 45 indicates a contact portion that comes into contact with the original 17. In this case, the peripheral portion of the transparent insulating substrate 31 outside the recess 33 becomes the contact portion, and the original i17 comes into contact with this portion.

A contact type image sensor having such a structure detects the light emitted from the light source 21 and transmitted through the transparent insulating substrate 31 or the original 17 (1).
The reflected light from the source i+7 is received by the light receiving section 13 provided inside the recess 33 and converted into an electrical signal.

Hereinafter, a method for manufacturing a contact type image sensor according to the present invention will be briefly explained.

After applying a resist to the transparent insulating substrate 31)H, a resist pattern is formed such that a portion of the substrate 31 is exposed in a stripe shape in order to form the recesses 33. Next, the portion of the substrate exposed from the resist pattern is etched to a suitable depth within the range of several micrometers to several tens of micrometers using plasma etching or a fluoric acid etchant.

Next, a first electrode 37, a light-receiving layer 39, a second electrode 41, and a surface protection insulating layer 43 are sequentially formed using a conventional photoetching process, plasma CVD, vapor deposition, and other film forming techniques. , the contact type image sensor of the present invention can be obtained.

Note that the size and position of the light receiving section 13 formed inside the recess 33 can be changed depending on the design. For example, the recess 33
The light receiving section 13 may be provided on the entire bottom surface of the recess 33 if the amount of light incident from the side surface is greater than the amount of light necessary for reading the document. Further, the light receiving section 13 may be provided on the side surface of the recess 33 as required.

Regarding the shape of the recess 33 provided in the transparent insulating substrate 31, it is preferable that the side surface of the recess 33 be a gentle slope so that the light receiving section 13 can be easily manufactured.
The light receiving section 13 is provided with the depth of the recess 33 inside the recess 33.
A gap is formed between the F-side surface of the document 17 and the surface of the document 17 to the extent that sufficient reflected light from the document 17 can be obtained, and an appropriate gap is formed so as not to reduce the reading resolution. If the depth is too shallow to obtain a
This results in a decrease in the ratio of Furthermore, if the depth of the recess 33 is made deeper than necessary, there may be problems such as a decrease in the accuracy of photolithography for forming the light receiving section 13, or a reduction in reading accuracy due to the leakage of reflected light to the adjacent light receiving section 13. Therefore, it is necessary to decide the shape of the four parts 33 in consideration of such points.

In order to prevent the reflected light from leaking to the adjacent light receiving section 13,
A plurality of recesses 33 may be provided in an array on the support body, corresponding to each of the light receiving portions provided in a large number in an array. An example of a contact type image sensor having such a structure is shown in FIG.

Incidentally, FIG. 2 is a top view showing the contact type image sensor array having such a structure as viewed from the document side. Further, the already shown FIG. 1 corresponds to the sectional view taken along the knee I line shown in FIG. 2.

In the embodiment described above, the light source is separately provided on the side opposite to the base 8!17 of the support (transparent insulating substrate) 31.
l"1 and 6 days ro +, t- is 1 λ bar -n upper shi body 3
1) For example, a light emitting element may be formed inside the protected recess 33 so as to be adjacent to the light receiving section 13, and this light emitting element may be used as a light source for reading the document. In this case,
The support body 31 does not have to be made of a transparent material.

Furthermore, the above-described embodiments have been described with reference to examples in which the light receiving sections 13 are provided in an array as a contact type image sensor. but,
For example, the arrangement of the light receiving section 13 can be changed depending on the shape of the original to be read, and the shape and arrangement of the recessed section 33 can be changed to configure various structures, for example, a contact image sensor in which the light receiving sections are arranged in a matrix. You can also do it.

(Effects of the Invention) As is clear from the above description, according to the contact image sensor of the present invention, the document is supported by the contact portion of the support portion outside the recess, and the document is supported by the light receiving portion provided inside the recess. A gap is formed between the upper surface of the document and the document surface, which is large enough to receive sufficient reflected light from the document, and narrow enough to allow high-resolution reading.

Therefore, the document can be read without providing a transparent insulating film several micrometers thick on the light receiving section as in the conventional case.

Therefore, it is possible to provide a contact type image sensor that can read a document with high resolution even if it has a simple structure.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the contact type image sensor of the present invention, FIG. 2 is a plan view for explaining the contact type image sensor of the present invention, and FIGS. 3 and 4 are conventional contact type image sensors. FIG. 2 is an explanatory diagram of an image sensor. 13... Light receiving section, 17... Original 21.
...Light source 31...Support (transparent insulating substrate) 33...Concave portion, 35...Window area 37.
...first electrode, 39...light-receiving layer 41...
Second electrode, 43... surface protection insulating layer 15...
・Contact part. Patent applicant Takashi Ogaki, attorney for Oki Electric Industry Co., Ltd. -″ 2-? The ＾A-Ken image of Hitoto’s true story, Part 3
Figure 4 of the theory of Nq with the image of the 2-year-old model of Figure I

Claims (1)

[Claims] (1) In a contact image sensor in which a support is provided with a light receiving section for receiving reflected light from a document, the light receiving section is provided in a recess provided in the support, and a portion of the support outside the recess is provided. A contact image sensor characterized by having a contact part that comes into contact with a document.