JPS63232366A - Image reader - Google Patents

Abstract

PURPOSE:To improve the characteristics of a sensor, such as of an optical responding speed by forming a conductive layer substantially equal to or slightly wider than that of a photodetecting region at a substrate side directly under the photodetecting region of a semiconductor layer formed of a pair of upper electrodes. CONSTITUTION:An auxiliary electrode 12 of a gate electrode with respect to main electrodes 6, 7 is formed corresponding only to the photodetecting region of a semiconductor layer 4 formed of a photodetecting window 8, or slightly wider in width. In order to reduce the superposition of the electrodes 6, 7 with the gate electrode as small as possible, it is desirable to form the gate electrode in the same size as that of the photodetecting region, but in order to prevent the superposition of masks during manufacturing steps from displacing due to the displacement of the mask alignment, a slightly wider gate electrode is preferably formed to reduce the irregularity of the capacity. Accordingly, the occurrence rate of short-circuits due to defects, such as pinholes is remarkably improved by the decrease in an optical response due to the capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an image reading device, which has a line sensor in which optical sensors are arranged in, for example, the − dimension, and is brought into close contact with the −-dimensional line sensor. The present invention relates to an image reading apparatus that is suitable for application to facsimile machines, image leagues, etc., which read image information while relatively moving a document involved in image reading.

[Prior Art] Conventionally, as an image reading device using a -dimensional line sensor, an original image is formed on a one-dimensional line sensor several centimeters in length using a reduction optical system to read original image information. It has been known. However, this type of image reading device requires a long optical path length to perform reduction or imaging, and furthermore, the volume of the optical system is large, making it difficult to construct the reading device in a compact size.

On the other hand, when using a same-magnification optical system using a long-dimensional line sensor with the same length as the JfX10I width, the volume of the optical system can be significantly reduced, and the reading device can be made smaller. A method using a focusing fiber is known as a method for realizing such a same-magnification optical system.

FIGS. 11(A) and 11(B) show an example of an optical sensor used in a conventional image reading device. In these figures, on an insulating substrate l such as glass or ceramics,
An auxiliary electrode 2 and an insulating layer 3 are formed on which hydrogenated amorphous silicon (hereinafter referred to as a-5t) is formed as a photoconductive layer.
:H), Cd5-5e, or the like is formed. Further, a pair of main electrodes 6 and 7 are formed via the doped semiconductor layer 5 for ohmic codon contact.
A light receiving section 8 is formed between them.

In such a configuration, for example, when a high-potential drive voltage is applied to the main electrode 7 with reference to the potential of the main electrode 6, when reflected light from the document surface enters the surface of the semiconductor layer 4, carriers increase. The resistance decreases, and this change can be read as image information. Further, by appropriately applying a voltage to the auxiliary electrode 2, it is possible to stabilize the output of the optical sensor and obtain an output proportional to the light intensity.

This kind of optical sensor corresponds to one bit of image reading, and it is arranged in a line on the substrate 1.
It is also possible to configure a one-dimensional line sensor of equal magnification type.

[Problems to be Solved by Development II] However, in the conventional image reading device, the projected area (the 11th figure(
(See A) is large, so six stitches are large, and therefore there is a problem that the light response speed is reduced. In addition, the insulating layer 3
If there is a defect such as a pinhole in the wafer, there is a high probability that a short circuit will occur at this defective portion, resulting in a reduction in product yield.

An object of the present invention is to eliminate these conventional problems, improve various sensor characteristics such as light response speed, and provide a highly reliable image reading device.

[Means for Solving the Problems] Therefore, in the present invention, an insulating substrate, a conductive layer, an insulating layer disposed on the conductive layer, a semiconductor layer disposed on the insulating layer, and a semiconductor layer are provided. In an image reading device having a pair of upper electrodes spaced apart from each other in contact with the conductive layer,
It is characterized in that it is formed on the base body side directly below the light receiving region of the semiconductor layer formed by the pair of upper electrodes, with a dimension that is approximately equal to or slightly wider than the light receiving region.

[Function] That is, according to the present invention, the conductive layer overlaps the upper electrode only slightly, so when the conductive layer is used as a gate electrode for the upper electrode, the capacitance of the overlapped portion can be significantly reduced. □ When there are defects such as pinholes, short circuits, etc. do not occur.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIGS. 1(A) and (B) show an optical sensor of an image reading device according to an embodiment of the present invention. Here, parts that can be configured in the same way as FIGS. 7(A) and CB) are shown in corresponding locations. The same reference numerals are given.

In this example, the auxiliary electrode 12 serving as the gate electrode for the main electrodes 6 (source side) and 7 (drain side) is provided so as to correspond only to the light-receiving region of the semiconductor layer 4 formed by the light-receiving window 8 or slightly Provided with wide dimensions.

In order to suppress the overlap between the main electrodes 6 and 7 and the gate electrode as much as possible.

It is desirable to provide a gate electrode with the same dimensions as the light-receiving area. However, in order to prevent overlapping deviations (Figure 2 (B)) due to mask misalignment during the manufacturing process, it is necessary to form a gate electrode with a slightly wider width. It is more preferable to do so, and the variation in capacity can be reduced. In any case, the overlap is significantly reduced compared to the prior art, and therefore the reduction in photoresponsiveness due to capacitance and the incidence of short circuits due to defects such as pinholes are significantly improved. Note that the semiconductor layer may have a structure as shown by the reference numeral 4' in FIG.

FIGS. 3A and 3B are a side sectional view and a top view of the sensor section of an image reading device that does not require an imaging system, respectively, as another embodiment of the present invention. Note that (A) is a cross-sectional view taken along the line 1-1 in (B) of the same figure. In these figures, numeral 108 is a sensor section arranged on a transparent substrate 11 such as glass in a direction perpendicular to the drawing to constitute a one-dimensional line sensor. In this sensor unit lO8, a light shielding layer 112 and an insulating layer 13 are formed on a transparent substrate l such as glass, and a photoconductive layer (7) L is formed thereon.
A semiconductor layer 14 such as -5t:H or cdSL18e is formed. Furthermore, a pair of main electrodes 116 and 117 are formed via a doped semiconductor layer 15 for ohmic contact, and a light receiving window 11B is formed between them.

In the sensor section 108 according to this example, the light shielding layer 112 is formed of a conductive material such as a metal, and is connected to an appropriate drive section, so that the main electrode 116 (source side) and the main electrode 117 (
1-' rain side). Further, the main electrodes 116 and 117 are formed in a comb shape,
By making them face each other alternately, the upper light-receiving windows 118 (FIG. 2B) are formed in a meandering shape, and the light-shielding layer 112 is also configured to correspond to the shape.

That is, the portion of the semiconductor layer 14 exposed by the window 118 receives reflected light from the original P, and photoelectric conversion is performed.

Furthermore, the distance between the FXMP and the sensor unit 10B is usually about 0.1 mm, and a reading resolution of 4 to 8 mm/mm can be obtained, but the above distance must be strictly controlled to ensure such resolution. The distance that must be controlled is controlled by coating the top surface of the sensor section 108 with a transparent protective layer 20.

In this configuration, the light L incident through the entrance window 19 of the transparent substrate 11 (for this incident light, the sensor @g10
8 is shielded from light by a light shielding layer 112), the original P is illuminated, the reflected light is received by the optical sensor section 108, and a read signal is extracted via electrode wiring. That is, for example, the potential of the main electrode 11B is used as a reference.
When a high potential drive voltage is applied to the semiconductor layer 17, when reflected light enters the surface of the semiconductor layer 14 through the light receiving window 118, the resistance decreases due to the increase in carriers, and this change can be read as image information. Can be done. Furthermore, by appropriately applying the 'Iπ pressure to the metallic light-shielding layer 112, it becomes possible to stabilize the output of the optical sensor and obtain an output proportional to the light intensity.

The optical sensor section 108 shown in FIGS. 3(A) and 3(B) corresponds to one bit of image reading, but by arranging a plurality of them in a line on the substrate 11, a -dimensional line is formed. Sensors can also be configured. That is, for example, in the width direction of the document P (the direction perpendicular to the moving direction of the document P indicated by the arrow in FIG.
If a resolution of 8 pixels/mm is provided over 6 mm, 1728 optical sensor sections 108 can be arranged.

Furthermore, the optical sensor section, a charge storage section (capacitor section) that accumulates the output of the optical sensor section, a switch section that transfers the accumulated charge and uses it for signal processing, and necessary wiring patterns, etc. They may be formed on the substrate in the same manufacturing process.

FIGS. 4A, 4B, and 4C are plan views showing an example of an image reading device in which such a photosensor section, a charge storage section, a switch section, etc. are integrally formed, respectively. , its BB sectional view and CC line sectional view are shown.

In these figures, 210 is a matrix wiring section, 208
212 is the optical sensor section, and 212 is the 7J storage 111 section.

213 is a transfer switch 213a and a charge storage section 21
2, a switch section including a discharge switch 213b for resetting the charge of No. 2; 214, a wiring that connects the signal output of the transfer switch to a signal processing section, which will be described later; and 223, the charge transferred by the transfer switch 213a is accumulated and read out. It is a load capacitor for

In this embodiment, the optical sensor section 208 and the transfer switch 213
A-3i:H film is used as the photoconductive semiconductor layer 14 constituting the discharge switch 213b and the insulating layer 2
As 03, silicon nitride 1%j (Si
NH) is used.

In addition, in FIG. 4(A), in order to avoid complexity, only the upper and lower two layers of electrode wiring are shown, and the photoconductive semiconductor layer 14
The photoconductive semiconductor layer 14 and the insulating layer 203 are not shown, and the photoconductive semiconductor layer 14 and the insulating layer 203 are formed in the optical sensor section 208, the charge storage section 212, the transfer switch 213a, and the discharge switch 213b. It is also formed between the wiring and the board. Further, at the interface between the upper electrode wiring and the photoconductive semiconductor layer, a doped a
-3i: H layer 205 is formed and ohmic contact is established.

In addition, in the wiring pattern of the line sensor of this embodiment, all signal paths output from each sensor section are wired so as not to intersect with other wires, and crosstalk between each signal component and gate electrode wiring are avoided. This prevents dielectric noise from occurring.

In the optical sensor section 208, 216 and 217 are upper layer electrode wirings. The light incident through the entrance window 219 and reflected on the document surface is transmitted to the a-3i:H light-guiding core semiconductor layer 2.
By changing the conductivity of 04, the current flowing between the upper layer electrode wirings 216 and 217 facing each other in a comb shape is changed. In addition,
Reference numeral 202 denotes a fully refracted light shielding layer connected to a driving section to be described later.

The charge storage section 212 is formed on the lower electrode arrangement 214, the dielectric of the insulating layer 203 and the photoconductive semiconductor 14 formed on the lower electrode wiring 214, and the photoconductive semiconductor layer 14, and is a photosensor section. The wiring is continuous with the upper layer electrode wiring 217. The structure of this charge storage section 212 is a so-called MIS (Metal-Insulator-
It has the same structure as a coy capacitor (Semiconductor). Although either positive or negative bias conditions can be used, the lower electrode wiring 214 can be always biased negatively.

In the figure, (C) shows a switch 213 having a thin film transistor (TPT) structure including a transfer switch 213a and a discharge switch 213b. It is composed of an insulating layer 203, a photoconductive semiconductor layer 14, an upper layer electrode wiring 225 serving as a source electrode, an upper layer electrode wiring 217 serving as a drain electrode, and the like. The gate insulating layer and the photoconductive semiconductor layer of the discharge switch 213b are the same layer as the insulating layer 203 and the photoconductive semiconductor layer 14, respectively, the source electrode is the upper layer electrode wiring 217, the gate electrode is the lower layer electrode wiring 227, and the drain electrode. is upper layer electrode wiring 2
It is 26. Moreover, 234 is a lower layer wiring connected to the gate electrode of the transfer switch 213a.

As mentioned above, at the interface between the upper layer electrode wirings 217, 225 and 226 and the photoconductive semiconductor layer 14, a-5i
:H n◆ layer 205 is interposed to form an ohmic contact.

As described above, the line sensor according to this example includes a light sensor section,
Since each component of the charge storage section, transfer switch, discharge switch, and matrix wiring section all has a laminated structure of a photoconductive semiconductor layer, an insulating layer, etc., each component can be formed simultaneously by the same process.

FIG. 5 shows, as still another embodiment of the image reading apparatus to which the present invention can be applied, an image reading apparatus having an imaging system with a short imaging distance and a same-magnification line sensor. , P is a document, and 301 is a conveyance roller for conveying the document M in the f direction, and its shaft 301A is rotatably supported at a predetermined position of the main body of the apparatus. Reference numeral 303 denotes a reading unit provided at a position facing the conveyance roller, and a plate spring 305 as a pressing member for elastically pressing the document P against the conveyance roller 301 over the entire width of the document P;
(7) LED array 3 as a lighting means for illuminating the
07. An optical system 309 in which convergent optical fibers are arranged to converge the reflected light from the original M, a conversion unit 308 provided with a photoelectric conversion element (optical sensor) that performs photoelectric conversion of the converged light, and holding each of these parts. It has a holding member 310.

That is, as the conveyance roller 301 is rotated by a driving means (not shown), the conveyance roller 301 is pressed by the pressing member 305.
The document P being pressed toward is guided and conveyed in the f direction.
7, the reflected light is supplied to the converter 308 via the optical system 309, and the images on the document P are sequentially read.

FIG. 6 shows an example of the configuration of an optical sensor constituting the converting section 308. In FIG.
is formed, and a photoconductive layer is formed thereon.
A semiconductor layer 14 such as or a-5i:H is formed. Furthermore, a doped semiconductor layer 315 for ohmic contact
A pair of main electrodes 316 and 317 are formed through the
A light receiving window 318 is formed between them. In addition, each part 3
Regarding the shapes of 12, 316, 317, etc., see Figure 3 (A
) and (B).

In such a configuration, for example, when a high-potential driving voltage is applied to the main electrode 317 with reference to the potential of the main electrode 316, reflected light is transmitted to the semiconductor layer 14 through the light-receiving window 318.
When the carriers are incident on the surface, the resistance decreases due to the increase in carriers, and this change can be read as image information. Further, by appropriately applying a voltage to the auxiliary electrode 312, it is possible to stabilize the output of the optical sensor and obtain an output proportional to the light intensity.

Although such an optical sensor corresponds to one bit of image reading, it is also possible to arrange the optical sensor in a line on the substrate 11 to form a one-dimensional line sensor 308 of the same magnification type.

For example, 1728 optical sensor sections 308 can be arranged in the width direction of the document P (the direction perpendicular to the moving direction of the document P indicated by the arrow in FIG. 5). Furthermore, the fourth
Similar to the embodiments shown in Figures (A) to (C), there is an optical sensor section, a charge storage section (capacitor section) that accumulates the output of the optical sensor section, and a signal processing unit that transfers the accumulated charges. A switch section for providing the same and necessary wiring patterns and the like may be formed on the substrate in the same manufacturing process.

FIG. 7 is a plan view showing an embodiment of an image reading device in which such a photosensor section, charge storage section, switch section, etc. are integrally formed.

In the figure, 410 is a matrix wiring section, 408 is a photosensor section, 412 is a charge storage section 413 is a transfer switch 4
13a and a switch section including a discharging switch 413b that resets the charge in the charge storage section 142, 414 is a wiring that connects the signal output of the transfer switch to a signal processing section to be described later, and 423 is a charge transferred by the transfer switch 413a. These are load capacitors for accumulating and reading out the information, and these can be constructed with a laminated structure similar to the parts 210, 208, 212, 213, and 223 shown in FIGS. 4(A) to (C), respectively. can. In the optical sensor section 408, 416 and 417 are electrode wirings serving as a source electrode and a drain electrode, respectively, and 402 is an auxiliary electrode wiring serving as a gate electrode. Since it is not designed to irradiate light from the back side, it does not have an entrance window as shown in FIG. 4(A).

In the line sensor according to the above example, each component of the optical sensor section, charge storage section, transfer switch, discharge switch, and matrix wiring section all has a laminated structure of a photoconductive semiconductor layer and an insulating layer. Therefore, each part can be formed simultaneously by the same process.

In each of the embodiments shown in FIGS. 3 to 7, the main electrodes were made to face each other in a comb-like manner, and the light-shielding layer or auxiliary electrodes were also shaped accordingly. )
Or Figure 2 (C).

Of course, the shape shown in (D) may also be used.

By using the conductive light-shielding layer or auxiliary electrode according to each of the above-described embodiments and adding, for example, the following circuit thereto, various controls can be performed.

FIG. 8 shows an equivalent circuit of the image reading device shown in FIG. 4 or FIG. 7.

In the figure, Sl, S2. ...SN (hereinafter referred to as SYI)
) is an optical sensor indicating the optical sensor section 208 or 408. CI, C2, . . . CN (hereinafter referred to as CYI) are storage capacitors representing the charge storage section 212 or 412, and store the photocurrent of the optical sensor SYI.

STI, Sr1,...STN (hereinafter referred to as 5TYI
) is the charge of storage capacitor CYI to load capacitor CXI (corresponds to load capacitor ?23 or 423)
Transfer switch (transfer switch 21)
3a or 413a), SRI, SR2,...
, 5RN (hereinafter referred to as 5RYI) is the storage capacitor C
This is a discharge switch (corresponding to the discharge switch 213b or 413b) that resets the charge of YI.

The optical sensor SYI, the storage capacitor CYI, the transfer switch 5TYI, and the discharge switch 5RYI are each arranged in a line in an array, and N pieces constitute one block, and the image reading device as a whole is divided into M blocks. For example, if there are 1728 sensors, N=32. M=54. The gate electrodes of the transfer switches 5TYI and the discharge switches 5RYI provided in an array are connected to the matrix wiring sections 210 and 410. Transfer switch 5TY
The gate electrode of I is commonly connected to the gate electrode of the transfer switch of the same rank in other blocks, and the gate electrode of the discharge switch 5RYI is circulated to the gate electrode of the transfer switch of the next rank in each block. connected.

The common lines (gate drive lines Gl, G2..., GN) of the matrix wiring section 210 or 410 are connected to the gate drive section 24.
Driven by 6. -Force signal output is lead wire 2
14 or 414 (signal output lines Dl, D2..., D
M) is connected to the signal processing unit 247.

In addition, the optical sensors Sl, ..., SN, ..., SNXM
gate electrode (t! light layer 202 or auxiliary electrode 402)
is connected to the drive source 250, and a negative bias is applied thereto.

In such a configuration, the gate drive line Gl.

G2. . . , GN is sequentially selected from the gate drive section 246 (VGI, VG2, VG3, . . . -).

VGN) is supplied. First, when the gate drive line G1 is selected, the transfer switch ST1 is turned on, and the charge accumulated in the storage capacitor C1 is transferred to the load capacitor C.
0th order gate drive transferred to XI! 21 line G2 is selected, the transfer switch ST2 is turned on, and the charge accumulated in the storage capacitor C2 is transferred to the load capacitor Cx.
1, and at the same time, the charge in the storage capacitor Ct is reset by the discharge switch SRI. Similarly, G3. G4. ....

GN is also selected and a read operation is performed. These operations are performed for each block, and the signal outputs VXI, VX2 . ....

VXM is the signal processing unit 247 (7) input DI, D2°...
・It is sent to the DM, converted to a serial signal, and output ~ In this way, by configuring the control system as shown in Fig. 8 for the image reading device as shown in Fig. 4 or Fig. 7. , the following control is rotation.

First, a depletion layer is formed in the semiconductor layer 14 related to photoelectric conversion by connecting the drive unit 250 that applies an appropriate negative bias voltage to the conductive light-shielding layer 202 or the auxiliary electrode 402. The dark current can be made sufficiently small, and the dependence of output on the amount of incident light (γ value), S/N ratio, etc. can be improved.

In addition, a bias voltage is applied to the conductive light shielding layer or auxiliary electrode according to the carriers that carry the current in the semiconductor layer, and a voltage with the same polarity as the bias voltage and a small absolute value is applied during the non-reading period. By providing the drive unit 250 to perform the previous reading, the output of the previous reading is erased and the next reading is performed, thereby improving the optical response speed.
In addition, it is possible to correctly respond to incident light and obtain stable output.

Furthermore, in an image reading device in which a plurality of optical sensors such as line sensors are arranged, different bias voltages are applied to the conductive light shielding layer 202 or the auxiliary electrode 402 depending on the arrangement position.
By providing a driving unit 250 that applies an voltage to the current, it is possible to obtain an output with a smooth distribution regardless of the position.

Next, FIG. 9 shows another embodiment of an image reading device in which a photosensor section, a charge storage section, and a switch section are integrally formed and does not have a lens. A) ~ (C
) In FIG. 0, corresponding parts are given the same reference numerals as those in the embodiment shown in FIG.

FIG. 1O shows an equivalent circuit of the device shown in FIG.

In the same figure, S t, I + S i, 2 H
゛” * S i, N (hereinafter referred to as Sl, where,
i is the block number and 1-N is the number of bits in each block. ) is an optical sensor indicating the optical sensor section 208.

(, +, + +Ci, ?+'''+Ci, N (hereinafter referred to as C0) is a storage capacitor representing the charge storage section 212, which stores the photocurrent of the optical sensor S.

STt, +, STi,z,..., STi
, Nr (hereinafter)

(denoted as STi) is the charge of the storage capacitor Ci as the load capacitor CX+, CX2, =, CXN
(corresponds to load capacitor 223), transfer switch (corresponds to transfer switch 213a), 3R1
,1,SRt,2,...,SRt,s (hereinafter.

S Rt ) is a discharge switch (corresponding to the discharge switch 213b) that resets the charge of the storage capacitor Ci.

The photosensor Si, the storage capacitor Ci, the transfer switch STi, and the discharge switch SR+ are each arranged in an array, for example, and N pieces constitute one block, and the image reading device as a whole is divided into M blocks. For example, if 1728 sensors are configured, N=32. M=54. The gate electrodes of the transfer switch STi and discharge switch SR+ provided in an array form are connected to the gate wiring section 210.
connected to. The gate electrode of the transfer switch STi is 1
Commonly connected within the second block.

The gate electrode of the discharge switch SRi is cyclically connected to the gate electrode of the transfer switch of the next block.

Common lines of the matrix wiring section 210 (gate drive lines Gl,
G2. ..., GM) are driven by the gate driving section 246. On the other hand, the signal output is carried out by the leader lines 230 (signal output lines DI, D2...,
DN) to the signal processing unit 247 (in block units).

In addition, the optical sensor Si, l +...* Si, N
g S2. '+ +..., SN, H gate electrode (
The light shielding layer 202) is connected to a driving source 250, and a negative bias is applied thereto.

In such a configuration, the gate drive line Gl.

G2. ..., GM is sequentially supplied with selection pulses (VGI, VG2, VG3, -) from the gate driving section 246.

When Gl is selected, the transfer switch STI is turned on, and the charge accumulated in the storage capacitor CI is transferred to the load capacitors CXI to CXH. When the gate drive line G2 is selected, the transfer switch STI is turned on. ST2 is ON
The charge stored in the storage capacitor C2 is transferred to the load capacitors CXI to CX32, and at the same time, the charge in the storage capacitor C1 is reset by the discharge switch SRI. Similarly, G3. G4゜...
, GM are also selected and read operations are performed.

These operations are performed for each block, and the signal outputs VXI, VX2, . . . of each block.

vxN is the signal processing unit 247 (7) input DI, D2°...
・The signal is sent to the DN, converted to a serial signal, and output.

In this example as well, the conductive light-shielding layer can be subjected to various controls in the same manner as described with reference to FIG.

As described above, the conductivity J#-' according to each of the above-mentioned examples
M-1111%+-%+1-1nh4 Symphony PWI↓$>-
Although it can be used for various types of control such as No. It is possible to significantly reduce the capacitance due to the overlapping portion of the insulating layer, thereby increasing the optical response speed, and to reduce the incidence of failures due to defects such as pinholes in the insulating layer.

In addition, in each of the above-mentioned parts, the main electrode (116, 117 in FIG. 1(A)) and the light-shielding layer (the first
In FIG. 11A, a staggered image reading device has been described in which the main electrodes 116 and 11 are placed on the opposite side of the semiconductor layer 14, but as shown in FIG.
A similar effect can be obtained by arranging the light shielding layer 7 and the light shielding layer 112.

[Effects of the Invention] As described above, according to the present invention, it is possible to improve various sensor characteristics such as the light response speed, and to realize a highly reliable image reading device.

[Brief explanation of drawings]

FIGS. 1(A) to (C) and FIGS. 2(A) to (D) are diagrams for explaining an image reading device according to an embodiment of the present invention, and FIGS. 3(A) and (B) 4(A), 4(B) and 4(C) are respectively a side sectional view and a top view of the sensor unit of an image reading device according to another embodiment of the present invention, and FIG. ) and CB), a plan view showing an embodiment of an image reading device in which a photosensor section, a charge storage section, a switch section, etc. are integrally formed, a sectional view taken along the line BB, and a sectional view of the image reading device shown in FIGS. 5 is a side view of an image reading device according to still another embodiment of the present invention; FIG. 6 is a side sectional view showing an example of the structure of the optical sensor in the device shown in FIG. 5; FIG. 5 is a sectional view showing an embodiment of an image reading device in which a photosensor section, a charge storage section, a switch section, etc. shown in figure t56 are integrally formed, and FIG. 8 is a cross-sectional view of the embodiment shown in FIG. 4 or 6. FIG. 9 is a plan view showing still another embodiment of the present invention, FIG. 1O is a circuit diagram showing an equivalent circuit of the embodiment shown in FIG. 9, and FIG. 12th sectional side view showing an example of another form of image reading device that is applicable and removable;
Figures (A) and (B) are a top view and a side view, respectively, showing an example of a conventional image reading device. 11.201... Transparent substrate, 13,203... Insulating layer, 14... Semiconductor layer, 20... Protective layer, 108°208.308.408... Optical sensor section, 112...
- Light shielding layer, 116, 117, 216, 217° 316.
317,416,417,312°402・? [Polar (distribution*), 212,412. , , -1 load storage section, 213,
413... Switch section, 213a, 413a... Transfer switch section. 213b, 413b...discharge switch section, 19°2
19...Entrance window. Figure 1 Figure 2 Figure 2 Figure 31 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 12

Claims (1)

[Claims] an insulating base, a conductive layer, an insulating layer disposed on the conductive layer, a semiconductor layer disposed on the insulating layer, and a pair of upper electrodes disposed in contact with and spaced apart from the semiconductor layer. In the image reading device, the conductive layer is formed on the substrate side directly below the light-receiving region of the semiconductor layer formed by the pair of upper electrodes, and has a dimension that is approximately equal to or slightly wider than the light-receiving region. An image reading device characterized by: