JPS5868968A - Photoelectric transducer - Google Patents

Abstract

PURPOSE:To increase a SN ratio by forming the photoelectric transducer by a photoconductive element, a charge storage element, an element for discharge connected in parallel with the charge storage element and an exchange amplifying element. CONSTITUTION:With the photoconductive elements S1-0-S54-31 formed by thin- film amorphous silicon or thin-film polycrystal silicon, one ends are connected to a bias power supply VB, and the other ends are connected to capacitors C1-0- C54-31 for storage. Transistors Q1-0-Q54-31 for discharging charges are each connected in parallel with several capacitor. Currents corresponding to incident luminous power flow through the photoconductive elements and charges are stored to the capacitors, potential corresponding to charges stored is supplied to transistors A1-0-A54-31 for conversion and amplification, which can be selected, and signal currents are outputted to data lines D0-D31.

Description

[Detailed Description of the Invention] The present invention relates to a photoelectric conversion device that transmits and outputs emitted light information as an electrical signal, and particularly relates to a 7T Kukumiri, digital copier (hereinafter abbreviated as 1) laser recording device, etc. The present invention relates to a photoelectric conversion device suitable for text and image human-powered devices, etc.

A conventional photoelectric conversion device includes a circuit having a conversion function and a scanner P' which extracts electrical signals output from the pixels in a time-series manner. Photodiode and MOS m PIT (yield
d Effect t'transistor) (M+,
) 8 type) as a component, or CCD (Charge Coupled
l')evice) and BBD (RacketBriga)
11 (Charge)
There are various methods such as those that include Thanster 1) device) as a constituent element, etc.
Whether it is pe or C'rD, 5ilk crystal (C-8
In order to use a wafer substrate (abbreviated as i),
The area of the light receiving surface of the charge conversion section is limited by the size of the C-8i wafer substrate. In other words, at present, if uniformity in all four areas is included, it is only a few nc at most.
Since only a C-8i wafer board with a size of about 1.5 h can be manufactured, such a C-8i wafer substrate 1r] is used for MO8 type or c'roll, and a charging conversion device is used as its component. In this case, the light receiving surface d
It cannot exceed the size of the previous C-8i wafer substrate.

Therefore, the light-receiving surface is shaped like this, and the light in a small area is
For example, when a charging conversion device having a conversion section is used as a manual device for a digital copier (hereinafter abbreviated as IJC), an optical system with a large aperture magnification is used to interpose the document between the document to be copied and the light-receiving surface. It is necessary to image the original document on the fluorescent screen through the optical system.

In this case, there are technical limits to increasing the darkness of the four images, as described below.

In other words, if the resolution of the photoelectric conversion unit is, for example, 10 mm, the length of the light-receiving surface in the user's direction is 3 cIL, and an attempt is made to copy a 4-size original, the image of the original on the light-receiving surface is The optical resolution is reduced to about 1/69, and the actual image resolution of the photoelectric conversion unit for an A4 document is reduced to about 1.5 lines/frame.

As the size of the original increases, it decreases at the ratio of (size of light-receiving surface)/(size of original).

Therefore, in order to solve this problem, in such a system, manufacturing technology that increases the resolution of the photoelectric conversion section is required. To achieve this resolution, devices must be manufactured with extremely high integration densities and with no defects in the components, but such manufacturing techniques have their own limits.

On the other hand, a plurality of charging conversion units are arranged so that the length in the longitudinal direction of the entire light-receiving surface is equal to the length in the main scanning direction of the eel-sized original that can be copied, and 1; Optical I? A method has been proposed in which the resolution is divided into the number of photoelectric conversion units to avoid a substantial drop in resolution.

Even in such a method, there are disadvantages as described below. In other words, when a plurality of photoelectric conversion parts are arranged, boundary areas where there is no light receiving surface inevitably occur between each photoelectric conversion part.
When the entire surface is glossy, the phosphor screen is no longer continuous and becomes blurred, and the optical image that is bundled together of the original is divided, and the portion corresponding to the boundary area is not manually applied to the charging conversion unit and is not used for copying. The resulting image becomes incomplete in the form of a line (white spots or areas corresponding to white spots in a line shape are removed), and it is divided into multiple light-receiving surfaces and becomes a condensed image. The captured optical image is an optically inverted image on each light-receiving surface, so the overall image is different from the optically inverted image of the original 41ψ.

Therefore, light reception 14! If you reproduce the optical image delivered as is, it will not be possible to reproduce the original manuscript.

As described above, in the conventional charging conversion device equipped with the photoelectric conversion section T-, it is extremely difficult to reproduce the 1# signal with an image resolution of 4>8 because the light receiving surface is small.

Accordingly, there are four charging conversion devices each having a long light-receiving surface and a charging conversion section having excellent release properties. Especially the manpower f of r bushimiri and DC! electricity or other
1. Buttocks or -rL.Applicable to a device that reads characters or AT, light reception equal to the size of the original to be reproduced + @ f 44 L, without reducing the resolution f required for the reproduced image. , original t-photoelectric converter 11 equipped with a photoelectric converter capable of faithfully reproducing the document t! equipment is essential.

The present invention d1 has been made in view of the above points, and the object of the present invention is to provide a photoelectric conversion section having an elongated light-receiving surface, high resolution, and high sensitivity. The object of the present invention is to provide a photoelectric conversion device gc which is extremely lightweight.

In the information processing device of the present invention, n photoelectric conversion elements are arranged in a line array, and the photoelectric conversion elements have an electrode common to the n photoelectric conversion elements, and an electrode common to the n photoelectric conversion elements.
A one-dimensional elongated photoelectric conversion unit having n electrodes provided independently between each photoelectric conversion unit, and a photoelectric conversion layer between the common electrode and the independent electrode: an input light The electrical signals outputted from the n photoelectric conversion elements in response to the signals are inputted in parallel and outputted in series; it includes a scanning-I11 section and a matrix wiring section.

Further details of the features of the phototransformation device of the present invention include a resistor, a charge accumulation time each individually and simultaneously connected to another piece of the photoconductive element, and a charge swell means. It is composed of a controllable discharge means for discharging the accumulated charge and nine stages for discharging the accumulated charge, and a control signal line of the discharge means is commonly wired for every predetermined number. , and the widened output line with the end width hand-reduced is wired with a vine trix to the wiring shaft of the horizontal puller.

1-LF The scanning circuit in the present invention will be explained.

Figure 41 shows the scanning circuit (1) in the present invention.A4
Approximately 8 pixels in the 4-handed direction / 14 images with the density of a dragon! r;*,
1728 (=54 x 32) required to achieve Nagatori
The photoconductive element 5l-PS54-31 is powered by VB, which is shown as an external bias power supply, and cs4-
Charges are accumulated in st in accordance with the amount of light incident on each photoconductive element. As a result, the above-mentioned Tsunden-? C,
-・~cs4-st selectable widening MO8) transistor 5! The connection point potential of -.~kg-H to the gate has a value corresponding to the amount of incident light for a certain charge accumulation time. In this scanning circuit, the charge storage capacitor is rather used as a widening MO8) Rungis 20, which is expected to be effective as a low frequency wave circuit together with the photoconductive element.
If a voltage is exclusively supplied to the common drain side wiring for every 32 lines, for example, the plotter drive line b1, the transistors Al-0 to A1 for increasing the width MO8 (in winter, it is 18) depending on the potential ltc at the connection point. -%-S becomes a biased gate and has a nine-channel resistance corresponding to the amount of light incident on the photoconductive element connected to each amplifier MO8 (or MI8) transistor company individually. . Therefore, the individual data ID0 to D31 are automatically transferred to the photoconductive elements.
A signal current corresponding to the amount of light incident on 31 is output. To ensure the above operation, individual data 4a D
It is obvious that the o-Dsl should be connected to a low impedance input circuit such as a current amplifier.

Here, the current female diode a1-...RI4-11
is the width increasing MO8 (or MI
8)) Provided to ensure the distance between the transistors (especially when non-redundant). Next, when the drive line A' is exclusively supplied with voltage 1, the M for discharging
O8 (or MI8)) transistor Ql-0 to Q1-st
Is it in a conductive state?The first light guide element group is also -o=st-st
The photocharge accumulated in the storage capacitor C1-.~ct-st belonging to K is transferred to the transistor Qs o-Qt~31.
It will be discharged through.

The common gate line of the discharging transistor 9 layers...~Qs-Furei is connected to the second photoconductive element group S-0~5s-st (L tube middle) transistors -〇~A Yue-31. Driving by connecting to the common line on the drain side has the advantage of reducing the number of control lines from external equipment to the photoelectric conversion means, but the drive is
It can also be easily assumed that they are driven separately due to problems such as differences in J voltage and drive type settings.

Eight transistors for increasing the width! - If the transmission characteristics such as the threshold voltage of A1411 are reconsidered and the common source line of the discharging transistor Q1-...Qsa-1 is fed from a separate bias power supply, the range of device design can be expanded. It is also clear that it gives rise to

An example of the scanning circuit 1s2 is shown in FIG. The first example shown in Figure 1 is used when high accuracy in reading out the amount of incident light is not required, or when the transistors used for width amplification are 11 products in the same lot and the transfer characteristics, especially the distribution of the threshold voltage, are small. can be expected to have sufficient effects, and the circuit is simple. However, especially when reading light amount information with high accuracy, the distribution of the transfer characteristics may become a problem. In the example shown in Figure 2, in order to solve the above problem, a resistor is inserted into the source circuit of the amplifier/transistor At-...Al4-m1, and the composite transfer characteristics are made uniform by current feedback. This is a precedent. The explanation of the circuit operation will be clear from the explanation of the @10 scanning circuit if it is understood that negative feedback using current feedback is applied to the operation of the amplifier transistor.

A third example of the scanning circuit according to the invention is shown in Fig. f43 (1).

(Listed in bl. In this example, nonlinear operating elements P, -0 to P
14-□ (only a part of which is shown in the figure) is used, and M is used as a means of separating the width-enhancing transistor from the common line on the drain side.
OS (or MI8) Transistors are used, especially the width increasing transistors AI-...A modification 31, the discharging transistors Qt-o to Qsa-s+, and the isolation transistors Tte to T'5-s1. A great effect is created by easily integrating elements that are manufactured using the same technology.

eK Fig. 3 (in case of Al, current feedback transistor p
, -o to common gate bias v to PS4-III.

It has the feature that the composite shear transfer characteristics can be programmed by changing the power supply voltage to □. Various components are shown in FIG.

In the scanning circuit described above, the output of the photoconductive element is always amplified (in the above example, it is converted into a current and amplified)! It sends a signal on the Trix wiring. In general, the conductivity of photoconductive elements is quite low, and the long wires required for digital copiers, facsimile machines, etc., which are the main uses of this photoelectric conversion means, can be processed through long wiring, and a good signal-to-noise ratio can be obtained. In many cases, we cannot expect it. One of the major features of the present invention is that, as shown above, the adverse effects of a portion of the photoconductive element output transverse resistance element are greatly reduced.

! Fig. s5 shows a schematic explanatory diagram of the configuration of the inventive charging conversion device. A group of photoconductive elements made in a row on a transparent substrate 50 such as glass (the element structure will be described later) 88x -8, Bs
4Fi, 11t wiring and capacitor group CB formed on the same board as a thin film! ~ A scanning circuit board integrated with CB54! It is connected to I52 by a wire pond. Mae l! ~to
The output line from wa is also ultimately led to the output electrode. The drive lines bl to b14 - external control lines are also led to the scanning circuit board through the vapor-deposited thin film electrode wiring on the board. The electric transformer element having the hybrid structure shown in the first embodiment has the same structure as the light guide element in the monolithic structure shown in the following embodiments, so it will be explained in detail.

The embodiment shown in Figure 6 is an example of the charging conversion device of the present invention in which the scanning circuit shown in Figure 1 i'4 is all realized on one substrate by thin film deposition. FIG. 6(a) is a plan view, and FIG. 6(b) is x-x' shown in the 6th LSI(a).
It is a cross-sectional view at the position indicated by .

On the substrate are a photoelectric conversion section 601, a charge/storage section 602,
A horizontal expansion section 603 and a discharge section 604, a matrix wiring section located on the right side of the drawing, and signal input/output and power supply electrodes are fabricated. The schematic diagram of the i-trix wiring section is the general one shown in Figure 7.
0 to 74 etc. correspond to through-hole connection parts, and 75 corresponds to a photoconductive part and a scanning circuit part.

The photoelectric conversion section is made of indium tin oxide (ITO) as an individual electrode so that the light that has passed through the transparent substrate 600 can enter.
A transparent conductive vapor deposited film 605 such as, and a light shielding electrode vapor deposited film 607 such as chromium (Cr) for uniformity of elementary shape.
Each pixel is manufactured independently by photo-etching. Further, a glow discharge is generated on the individual electrodes in a mixed gas of 8iH4 gas and H snow gas, and by decomposition of SiH4, a BP1 conductive element 606 is produced for each pixel by etching. Subsequently, the common counter electrode 608 is wired with a metal material such as AJ (through a vapor deposition etching process).

In the vapor deposition process using the discharge decomposition method, 8iH4/H2' gas is mixed with a suitable concentration of PH, gas or B, H, and gas gold to cover a wide range of various conductivity types. ;- can be deposited.For example, the above a-Si'/f,
The conductive layer's F° area and lower surface are doped with P atoms in a large amount to ensure resistive contact with the electrode metal.

:H ie In the following explanation, the method of forming the a-8t layer of each conductivity type will not be mentioned.

Now, the charge storage section 602 is pattern etched n,
5il formed by sputtering method etc.
It consists of a capacitor with a hole made by thin film wiring with a ground electrode 609 sandwiching an N4 evaporated '4' 618.

The material of the drain electrode 610 is A, which uses the potential generated by the dust to remove the n soil layer by utilizing the fact that the transition speed of the MI8 structure depends on the doped P atoms aWl.
Due to the use of metal such as LA, the mountain - in the f41 diagram
- Forms a Schottky barrier diode designated by ~R14-H which functions as an isolation diode. Further, an n-soil layer is left in the □ portion where the source side electrode 613 is in contact, maintaining a 9-resistance contact. The absolute layer 619 is made of an insulating film such as 8LHN4.8 iol 7LHN4.8IOL SUBATA+FI, and is particularly designed to reduce the electrostatic coupling between the lateral resistance electrode 610 and the luminescent electrode 607, which is the output line from the photoelectric conversion section. It is formed for the purpose of stimulating.

The MI8 structure transistor constituting the discharge section 604
Connected through layers. The n+1- layer in the a-8i layer between the drain electrode 614 and the source electrode 616 is removed by photoetching.

(Fig. 48fa), (The photoelectric conversion gcI11 shown in BL is an example in which a current feedback resistor "1 o-F'54st" not shown in Fig. 2 is inserted, and Fig. 8 (a> is a schematic plan view, figure(
b) is a sectional view taken along line X-X' in '48□--Figure 1al. The member arrangement 1 is almost the same as that shown in FIG. 6, except that the resistance is low, and it may be constructed using an appropriate metal oxide, boride, nitride, etc.

An example using a four-way feedback element and a 17M2S) transistor is shown in FIGS. 9A and 9B. Corresponding scanning times
has already been shown in Figure 3 (a). In this example also #
It is similar in many respects to the component arrangement shown in fS13M,
A current feedback 615 is placed parallel to the discharge 615, and a Mis
? The transistor 900 is also connected to the charge storage 4602.
The only difference is that the same (MI8) transistor 901 is formed as an isolation element at °I11 with the Ji1M18) transistor 904. Note that the rain is designed to maintain resistive contact with the electrode metal. Also, MI for separation
8) Ranjistagut is input line 902 of bond selection signal line bi
Toyokawa also posted an example of forming a bow which is shared with the transistor power supply line VD on the drain side as a supplementary explanation to the figure.

As shown in the embodiments above, in the present invention, in a conventional photoelectric conversion device that scans and outputs a large amount of optical information, it is possible to achieve a longer length, and a 4kK Therefore, we have made it possible to create a photoelectric conversion device that greatly reduces the influence of noise, which is a problem when photoconductive elements with high impedance are widely arranged.

[Brief explanation of the drawing]

FIGS. 1 to 3 (at, (b) are scanning circuit diagrams for explaining the scanning circuit according to the present invention, and FIG. 4 6 ↑
, Figures 5 and 6 fa), (bl
are explanatory diagrams for explaining embodiments of the present invention, respectively.
The figure is in the present invention! Explanatory diagrams for explaining the Trix wiring section, Figure 8 fal, (bl and Figure 9 (a),
(b) is an explanatory diagram for explaining another example of the present invention. Actor Canon Co., Ltd. −

Claims (1)

[Claims] A photoconductive element made of a plurality of thin film silicones having one end commonly wired by a power supply wiring, a charge storage means individually electrically connected to another end of the photoconductive element, and the charge storage. A controllable discharging means for discharging the electric charge accumulated in the electric charge storage means, and a controllable discharging means for reading the generated voltage and converting and amplifying it into a voltage or a current according to the amount of electric charge accumulated in the electric charge storage means, which can be selected. and amplification means made of polycrystalline silicon, control signal lines of the output and wL means are wired in common for every predetermined number, and the conversion and amplification rjj output lines of the amplification means are connected to selection inputs. A photoelectric conversion device characterized by matrix wiring according to the wiring.