JPH03227165A - Scanner circuit device - Google Patents

Abstract

PURPOSE:To obtain an output corresponding accurately to scanning by connecting photoelectric conversion circuit elements in common, using one signal string to scan the elements, extracting an output of each element, using a differentiating circuit to detect a level change at a connecting point and controlling the scanner circuit based thereupon. CONSTITUTION:A voltage V0 of a power supply 1 is increased linearly, a voltage at points P0-P3 is increased and photoelectric conversion elements S0-S3 are sequentially reverse-biased. A charge current flows to an element whose equivalent capacitance is discharged by optical input through block diodes Dc0-Dc3 and a capacitor 10 of an IV conversion circuit 3. The capacitor 10 is charged by an output Iout of unit circuits K1-K3 and a switch 11 is periodically closed to divide a current change in the elements S0-S3 to output a voltage V0. A change in levels Vp0-Vp3 of the points P0-P3 is detected by differentiating circuits F0-F3 from a control signal Vr of the switch 11 and a control signal Vs of a sampling circuit 4 and the control signals are formed based thereon. Thus, even when the mutual time width at ON time of diodes Db0-Db3 is changed, since a read point of time is changed, the output of the elements S0-S3 is read accurately.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a scanning circuit device for sequentially supplying voltage to a plurality of circuit elements, and more particularly, to a scanning circuit device suitable for a -dimensional image sensor. Related to circuit devices.

[Issues to be solved by the prior art and the invention] An image sensor includes a plurality of photoelectric conversion elements for converting optical information into electrical signals, and electrical signals are generated by electrically scanning the plurality of photoelectric conversion elements. It has an analog switch for selectively obtaining. For example, an analog switch is disclosed in Japanese Patent Application Laid-open No. 63-
As disclosed in Japanese Patent No. 2377, it is made of a field effect transistor (FET) and is arranged near a plurality of photoelectric conversion elements.

By the way, in an image sensor with an integrated circuit configuration,
The width of one charging conversion element, that is, one pixel (for example, 125
One field effect transistor must be placed to fit within .mu.m).

However, it is not easy to form a field effect transistor to fit within such an extremely narrow width, and the three wiring conductor layers for the drain, source, and gate of the field effect transistor are placed in predetermined locations on the substrate. When the three wiring conductor layers are provided within the same width, the width of the three wiring conductor layers inevitably becomes narrower, and the yield of manufacturing the image sensor becomes lower. In order to solve this kind of problem, the applicant filed a patent application in
No. 3-190848 and Japanese Patent Application No. 1-198279, which is the above-mentioned application claiming domestic priority, propose a scanning circuit device using a series circuit of diodes. Not disclosed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for accurately and easily extracting an output from a scanning circuit device using a diode having fewer electrodes than a transistor.

[Means for Solving the Problems] To achieve the above object, the present invention will be described with reference to the reference numerals in the drawings showing the embodiments. A circuit in which a plurality of first diodes Da1 to Da3 each having a second electrode and a second electrode are connected in series, one end of which is connected to the voltage source l, and each of the first diodes Da1 to Da3
Each of the first diodes Da1 to Da3 has a directionality such that a forward current of 3 flows based on the sawtooth wave.
has, and each first diode Da1 to Da
a first series circuit in which the first electrodes of No. 3 are arranged on the side of the voltage source 1, each of which has a first resistor or capacitor Ra1 to Ra3 or Ca1 to Ca3 and a second diode Dbl to Db3; It consists of a circuit connected in series,
The second diode of each of the first diodes Da1 to Da3
and the other end of the voltage source 1, and each of the second diodes Db1 to Db3 has a directionality such that the forward current of the second diode Db1 to Db3 flows based on the sawtooth wave. a plurality of second series circuits included in the diodes Db1 to Db3, the second electrodes of the respective first diodes Da1 to Da3, and the voltage source 1;
a plurality of second resistors or capacitors Rb1 to Rb3 or Ca1 to Ca3 respectively connected to the other end thereof, and the first resistor or capacitor Ra1 to Ra3 or Ca1;
A connection point P between ~Ca3 and the second diodes Dbl~Db3.

A plurality of circuit elements SI to Ss to be scanned are connected between the common current output line 2 and the common current output line 2, respectively, and the other end of the voltage source 1 is connected between the common current output line 2 and the other end of the voltage source 1. a common current-voltage conversion circuit 3, a signal processing circuit for controlling the current-voltage conversion circuit 3 or its output to obtain readout outputs of the scanned circuit elements S, ~S3, and the connection point P1. -P, a plurality of differentiating circuits F1-F for timing detection connected to P, respectively, and a control signal forming circuit 5 forming a signal for controlling the signal processing circuit based on the outputs of the differentiating circuits F1-F. The present invention relates to a scanning circuit device consisting of.

Further, as shown in claim 2, the first resistor R of claim 1
It is possible to connect capacitors 01 to C3 or diodes having an equivalent function in place of a1 to Ra3, and to connect resistors R1 to R3 in place of second diodes Db1 to Db3.

Note that the signal processing circuit corresponds to at least one of the current-voltage conversion circuit and the sample-hold circuit of the embodiment, or a peak-hold circuit (not shown) for the output current Iout.

[Operation] A plurality of scanned circuit elements 81 to S3 according to claims 1 and 2.
are connected in common, so the outputs of the plurality of scanned circuit elements 81 to S3 are taken out as one signal train. The signal processing circuit detects potential changes at the connection points P1 to P3 using differentiating circuits F1 to F3, and is controlled by a control signal determined based on this, so it is possible to obtain an output that accurately corresponds to scanning. .

[Embodiment] A one-dimensional image sensor according to an embodiment of the present invention shown in FIG. , a current voltage conversion port l#33 connected to the common current output line 2,
It consists of a sample hold circuit 4, differentiating circuits FO to F3 for timing detection, waveform shaping circuits Go to G3, and a control signal forming circuit 5. This -dimensional image sensor is configured to be able to detect more than four pixels. However, since it is difficult to show the entire configuration of this one-dimensional image sensor in the drawing, only a part of it is shown in FIG.

For three unit circuits that are the same, +, Kt, and Ks are
First diodes Dal, Ca2, Ca3, second diodes Db1, Db2, Db3, and first resistor Ra1
, Ra2, Ra3 and second resistors Rb1, Rb2, Rb
3, a photoelectric conversion element S turtle as a scanned circuit element,
S2, Ss and blocking diodes Dc1, Ca2
, Ca3. Another unit circuit arranged between the voltage source 1 and the unit circuit 1 includes a second diode DbO5, a first resistor Ra01, a photoelectric conversion element So, and a blocking diode DCO. 0 in the unit circuit, + in another unit circuit, 2 in the first diode in K, eDal, Da2, Da3, and the second resistor RbO.
However, the unit circuit Ko
It is also possible to connect to another unit circuit 1, K, , K, corresponding to the first diode and the second resistor. Further, if necessary, 0 can be omitted from the first-stage unit circuit of the image sensor shown in FIG.

Three first diodes Da1, Da2, Da3 having an anode (first electrode) and a cathode (second electrode)
One end (left end) of a circuit in which these are connected in series with each other (first series circuit) is connected to one end of a voltage source 1. The first diodes Da1, Da2, and Da3 have directionality that is biased in the forward direction by the voltage of the voltage source 1. That is, the anodes of the first diodes D81 to Da3 (the first
electrodes) are arranged on the voltage source 1 side. Note that when the upper terminal of the voltage source 1 is negative, the cathodes of the first diodes Da1 to Da3 are arranged on the voltage source 1 side.

First resistors Ra1, Ra2, Ra3 and second diodes Dbl, Db2, A circuit (second series circuit) in which Db3 is connected in series is connected to each other. In the unit circuit 0, a series circuit including a first resistor RaO and a second diode DbO is connected between one end and the other end of the voltage source 1. Second diode DbO1Db
1, Db2, and Db3 have the directionality of being biased in the forward direction by the voltage of the voltage source 1.

Each unit #l consists of a photodiode at the interconnection point P0, Pl, P2, Ps of the first resistor Rag, Ra1, Ra2, Ra3 in Ko, Kt, 2, Ks and the second diode DbO1, Db1, Db2, Db3. The cathodes of the photoelectric conversion elements So, St, St, and Ss are connected to each other. Photoelectric conversion element S,, Sl,
The anodes of St, S, are blocking diodes DcO1Dc to prevent mutual interference of photoelectric conversion elements S0 to S.
Common via l, Dc2, and Dc3! It is connected to the outflow output line 2. A current-voltage conversion circuit 3 connected between the common current output line 2 and the ground is a circuit that obtains a voltage corresponding to the output current 1 out.

Note that each of the photoelectric conversion elements So to Sj is substantially connected in parallel to the diodes DbO to Db3 of each part 2.

The photodiodes serving as the photoelectric conversion elements So, St, St, and Sj are connected so as to be reverse biased by the voltage of the voltage source 1, so the current flowing therein is extremely small.

The waveform shaping circuits Go to G3 connected to the output lines of the differentiating circuits FO- and -F3 include a Schmitt trigger circuit and a monostable multivibrator, and form narrow timing pulses corresponding to the differential output, and control signals. to the formation circuit 5.

The control signal forming circuit 5 supplies a control # signal to the current-voltage conversion circuit 3 via a line 6, and supplies a filJ# signal to the sample hold circuit 4 via a line 7.

Details of each part of the image sensor shown in FIG. 1 are as follows.

The voltage source 1 consists of a circuit that generates a sawtooth wave, and periodically generates a sawtooth wave or sweep signal having a ramped voltage as shown in FIG. 4(A). The maximum amplitude value of the sawtooth wave in FIG. 4(A) is
1 to Da3 and DbO to Db3 are set to values that can turn them on.

Note that the rising speed of the sawtooth wave is slower than the rising speed of the first and second diodes Da1 to Da3 and DbO to Db3, and the vertical axis (voltage) in FIG. 4(A) is shown in FIG. 4(B). It is compressed by comparison.

Photoelectric conversion elements Sa to Sj, first diodes Da1 to D
a3, the second diodes DbO to Db3, and the booking diodes DcO to Dc3 are PIN junction diodes, respectively, and are connected to the hydrogenated amorphous silicon semiconductor layer and the semiconductor layer provided below the semiconductor layer. and the other electrode layer provided above the semiconductor layer, and are provided on a common insulating substrate (not shown). When the width given to each unit circuit KO~ formed by an integrated circuit is 125 μm, the width of the wiring conductor layer of the first and second diodes Da1~Da3 and DbO~Db3 is about 20 μm. I can do it. If a field effect transistor is used for scanning the photoelectric conversion elements S0 to S, the width of the wiring conductor layer will be approximately 10 μm, which is narrower than in this example, and thus the yield of image sensor manufacturing will be reduced. Deteriorate.

Since the photoelectric conversion elements S0 to Ss are reverse biased,
This is equivalently represented by a parallel circuit of a capacitance Cs and a current source Is proportional to the light intensity shown in FIG. Note that the value of the current flowing through the equivalent capacitance Cs of the photoelectric conversion elements S0 to S is extremely small, and the value of the current flowing through the first diodes Da1 to D
When a3 and the second diodes DbO to Db3 are turned on, the voltage across them, that is, the forward voltage Vf, is approximately 1V. The first resistors RaO to Ra3 are each 100Ω
The second resistors Rb1 to Rb3 are each 1 to Ω, and these are T i 02 , Ta S I O
It is made of a material such as x or NiCr.

The current-voltage conversion circuit 3 includes photoelectric conversion elements S0 to S.

This circuit converts the current into a voltage, and in this embodiment, it is made up of an integrating circuit, and is made up of a capacitor 10, a discharge (reset) switch 11, and an amplifier 12. Since the capacitor 10 is connected between the anodes of the photoelectric conversion elements S0 to S, and the ground, the capacitor 10 is connected between the anodes of the photoelectric conversion elements S0 to S,
, is charged by the current flowing through it.

A switch 11 connected in parallel to the capacitor 10 separates and detects the output currents of the photoelectric conversion elements So to S, respectively.

The capacitor 10 is turned on at or near the time when charging of the capacitor 10 is completed, and the capacitor 10 is placed in a discharge state. One end of the capacitor 10 is connected to the sample and hold circuit 5 of FIG. 1 via an amplifier 12. The sample and hold circuit 5 samples the output of the current-voltage conversion circuit 3 immediately before the discharge switch 11 starts to turn on, and holds the sample.

Each of the differentiating circuits FO to F3 consists of a capacitor C connected to connection points P0 to P, and a resistor R connected between the output line of this capacitor C and the ground.
Figure 4 (
The potential of the connection point Po, p shown in B) ■ pO ~ Vp3
In response to changes in , differential outputs HO to H3 are generated as shown in FIGS. 4(C) to 4(F).

The waveform shaping circuits GO~G3 adjust tl and t based on the differential outputs HO~H3 as shown by dotted lines in FIG. 4(C)~(F).
Timing signals are output at times 2, t6, and t7.

The control signal generation circuit 5 is composed of a combination of a plurality of monostable multivibrators, and generates a sample hold control signal Vs shown in FIG. 4(G) and a discharge control signal Vs shown in FIG. 4(H).
generate r. The sample hold control signal Vs in FIG. 4(G) rises in synchronization with the leading edge of the timing signal shown by the dotted line in FIGS. 4(C) to (F) and continues for a certain period of time. The discharge control signal vr in FIG. 4(H) rises a little later than the leading edge of the sample-and-hold control signal in FIG. 4(G), and falls after a relatively short period of time.

[Operation] In the image sensor shown in FIG. 1, when the sawtooth wave shown in FIG. 4(A) is generated from the voltage source 1, the first diodes Da1 to Da3 become conductive in sequence. That is, as the slope voltage of the sawtooth wave gradually increases, the potential V at point P0
The pO gradually increases as shown in FIG. 4(B). As a result, when the potential VpO at point P(l reaches the forward voltage Vf (approximately IV) of the second diode DbO of 0 in the unit circuit, the diode DbO turns on and the potential VpO at point P0
pO becomes a substantially constant value (approximately Vf), that is, a saturation voltage value.

Almost at the same time as the second diode DbO of 0 in the unit circuit is turned on, the first diode Da of the unit circuit Kl is turned on.
1 is also turned on. During the period in which the first diode Dal of the unit circuit KI is non-conducting (off state), the cathode of the first diode Dal is at almost zero volts, but the first diode Da1 is in the on state and the voltage source is further increased. 1
When the voltage Vd of the first diode Dal increases, the cathode voltage of the first diode Dal follows the voltage Vd and increases. That is, the first
When the diode Dal turns on, the voltage across it is almost fixed to the forward voltage Vf, so the power supply voltage Vd
A voltage obtained by subtracting the forward voltage Vf of the diode Da1 from the voltage is applied across the second resistor Rb1. Further, during a period in which the positive second diode Dbl in the unit circuit is non-conductive, the potential at the point P becomes approximately equal to the voltage across the second resistor Rbl. Therefore, after the first diode Da1 is turned on, the potential Vpl at the point P1 gradually increases as shown in FIG. 4(B). When the voltage Vf is reached, this turns on, and the potential Vpl at point P1 becomes an almost constant value (Vf).Almost at the same time as the second diode Db1 in the unit circuit turns on, the second diode Db1 in the unit circuit turns on. The first diode Da2 is turned on, and a potential Vp2 is obtained at the point P2 as shown in FIG. 4(B). When the slope voltage of the sawtooth wave supplied from the 1c pressure source 1 further increases, the first diode Da3 of the unit circuit Kj turns on, and the potential Vp3 of FIG. 4(B) is obtained at the point P. 4 (
When the voltage changes sequentially as shown in B), the photoelectric conversion elements S0 to Ss connected between each point P0 to Ps and the ground via the capacitor 10 are sequentially driven. That is, the photoelectric conversion elements S0 to S are electrically scanned.

In the circuit of FIG. 1, photoelectric conversion elements S0-S.

are arranged in − dimensions. This photoelectric conversion element S0~
When reading optical information in S3, first, the first diodes Da1 to Da3 and the second diodes DbO to Db3
The voltage source 1 generates a voltage that can turn on all of the devices. Note that the first diodes Da1 to Da3
The voltage for turning on all of the second diodes DbO to Db3 can be given by a sawtooth wave as shown in FIG. 4(A).

That is, the maximum value of the sawtooth wave and the voltage value in the vicinity thereof are the values of the first and second diodes Da1 to Da3 and DbO to D
You can turn on all of b3.

During the period when all of the first diodes Da1 to Da3 and the second diodes DbO to Db3 are in the on state, the point P
0 to P3, each photoelectric conversion element S0
~S, is reverse biased and a capacitance Cs, equivalently shown in FIG. 2, is charged.

Note that since the equivalent capacitance Cs is extremely small, charging of the equivalent capacitance Cs can be achieved by the current in the region before the point where the forward current of the blocking diodes DcO to Dc3 rises sharply.

When an optical signal obtained from an object # (not shown) such as a facsimile document placed opposite to the image sensor in FIG. 1 is input to photoelectric conversion elements S0 to S3,
Depending on the presence or absence and size of the optical signal, the photoelectric conversion element S・~S
The amount of charge charged in the equivalent capacitance Cs of s changes.

That is, among the photoelectric conversion elements S0 to S, the equivalent capacitance Cs is discharged in the one to which the optical signal is input, and the equivalent capacitance Cs is discharged in the one to which the optical signal is not input.
The amount of discharge of the zero equivalent capacitance C8, where no discharge occurs, changes depending on the amount of light. There are two methods for providing optical input to the photoelectric conversion elements S and S1. One method is to constantly apply optical input to the photoelectric conversion elements S0 to S, and the other is a method for a predetermined period (for example, the voltage V of voltage source 1
This method provides optical input only during periods when d is zero volts.

When the voltage Vd of the voltage source 1 increases linearly with time as shown in FIG.
As shown in the figure, potentials VpO1Vpl, Vp2, and Vp3 are obtained, and thereby the photoelectric conversion elements S0 to S3 are sequentially reverse biased. In other words, the voltage for charging the equivalent capacitance Cs shown in FIG.
Applied to 0 to Ss. At this time, photoelectric conversion elements S0 to S
Among the equivalent capacitances Cs of , a charging current flows to those that are discharged due to optical input, but no charging current flows to those that are not discharged due to no optical input, photoelectric conversion elements S0 to S1. Since the charging current of the equivalent capacitance Cs flows through the blocking diodes DcO to Dc3 and the capacitor 10, the voltage of the capacitor 10 changes depending on the presence or absence of the charging current of the equivalent capacitance Cs of the photoelectric conversion elements S0 to S. FIG. 4(1) shows a photoelectric conversion element S. ~S, the current I out of the common current output line 2
It is shown. In this FIG. 4(I), three photoelectric conversion elements S0. There is a large optical input for S+, Ss,
The current I out when there is a small optical input to one photoelectric conversion element 82 is shown. The current I out increases following the rise in the potentials VpO to Vp3 at each point P o to Ps, and decreases as the potentials vpO to Vp3 approach saturation.

The capacitor 10 is charged with the current I out shown in FIG. 4(I), and this charging voltage Vc changes as shown in FIG. 4(J). In order to separately detect current changes in the photoelectric conversion elements S0 to Ss, the discharge switch 11 is periodically turned on. The sample and hold circuit 4 operates in synchronization with the leading edge time points t1, t2, t6, t7, and t8 of the pulse of the sample and hold control signal Vs shown in FIG. 4(G).
) is sampled and held for a pulse width (for example, t2 to t5) shown in FIG. 4(G). Since the value of the sample in FIG. 4(J) at time t7 is low, the output voltage VOUT during the period from t7 to 78 is also low.

The output voltage vout of the sample hold circuit 4 is shown in Fig. 4 (
As shown in K), it corresponds to the optical input of the photoelectric conversion elements So to S1. Note that the discharge period of the capacitor 10 by the switch 11 is immediately after the leading edge of the sample-and-hold control signal Vs in FIG. 4(G), as shown, for example, from t3 to t4 in FIG. 4(H).

As is clear from the above explanation, the control signal Vr for the discharging switch 11 of the capacitor 10 and the control signal Vs for the sample-and-hold circuit 4 are not generated at regular intervals, but are
The change in potentials VpO to Vp3 at point PO-P3 is detected and formed based on this. Therefore, the mutual time widths t1 to t2, t when the second diodes DbO to Db3 are turned on
Even if 2 to t6, t6 to t7, and t7 to t8 change, the reading time also changes, so the outputs of the photoelectric conversion elements S0 to S can be accurately read.

[Modifications] The present invention is not limited to the above-described embodiments, and, for example, the following modifications are possible.

(1) Blocking diodes DCO to Dc3 for preventing mutual interference of photoelectric conversion elements S0 to Ss are connected in series to first resistors Ra1 to Ra3, or second resistors Rb1 to Db3 and first resistor Ra1 ~Ra3.

(2) The photoelectric conversion elements S0 to Ss can be made into photoconductive mode elements.

(3) The polarity of each diode and the polarity of the voltage source 1 can be reversed. (4) If the number of pixels read by the image sensor according to the embodiment is increased, the driving voltage Vd must be increased accordingly. It is desirable to set the maximum number of pixels to be read to about several dozen. If the number of pixels is increased than this, the image sensor may be divided into a plurality of blocks and driven.

(5) Instead of a sawtooth wave with a region of ramped voltage that increases linearly with time, a sawtooth wave that changes quadratically, as shown in Figure 5, or stepwise, as shown in Figure 6. It is possible to use varying sawtooth waves.

(6) As shown in FIG. 7, the second resistor Rb1 in FIG.
Capacitors Cb1 to Cb3 may be connected in place of Rb3, and capacitors Cb1 to Cb3 in FIG. 7 may be replaced with diodes connected to be reverse biased. This diode acts as a capacitor.

(7) As shown in FIG. 8, it is possible to replace the first resistors RaO to Ra3 in the circuit of FIG. 1 with capacitors CaO to Ca3. In this case, it is necessary to increase the leakage current of the second diodes DbO to Db3 to form a capacitor discharge circuit.

(8) As shown in FIG. 9, the first resistor RaO in FIG.
~Ra3 can be replaced with capacitors CO~C3, and diodes DbO~Db3 of section 2 can be replaced with resistors RO~R3. Further, the capacitors CO to C3 can be replaced with equivalent capacitance diodes connected in a reverse bias direction. Note that the capacitance values of the capacitors CO to C3 are set to be sufficiently larger than the capacitance values of the photoelectric conversion elements S0 to Ss.

(9) The current-voltage conversion circuit 3 can be modified in various ways. For example, it can be a combination of a current-voltage conversion circuit of the type in which a feedback resistor is connected to an operational amplifier and an integrating circuit connected to this output stage.

(10) It is possible to create a circuit in which the first stage DbO1RaO130 and DcO are omitted.

[Effects of the Invention] As described above, according to the present invention, it is possible to easily perform timing detection for reliably operating a scanning circuit device using a diode.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an image sensor according to an embodiment of the present invention, Fig. 2 is an equivalent circuit diagram of the photoelectric conversion element shown in Fig. 1, and Fig. 3 is a circuit diagram showing the current-voltage conversion circuit shown in Fig. 1. , Figure 4 is a waveform diagram showing the state of each part of the circuit in Figure 1, Figures 5 and 6 are waveform diagrams showing modified examples of sawtooth waves, Figures 7, 8, and 9 are modified examples. FIG. 2 is a circuit diagram illustrating an example image sensor. DESCRIPTION OF SYMBOLS 1... Voltage source, 2... Common current output line, 3... Current-voltage conversion circuit, 4... Sample hold circuit, 5...
...Control signal forming circuit, S0-Ss...Photoelectric conversion element, FO-F attack...Differentiating circuit.

Claims (1)

[Claims] [1] A voltage source (1) for supplying a sawtooth wave, and a plurality of first diodes (Da1 to Da3) each having a first electrode and a second electrode are connected in series. a circuit connected to the voltage source (1), one end of which is connected to the voltage source (1);
In addition, each of the first diodes (Da1 to Da3) has a directionality such that the forward current of each of the first diodes (Da1 to Da3) flows based on the sawtooth wave.
has, and each first diode (Da1 to D
a3) a first series circuit in which the first electrode is placed on the side of the voltage source (1), each connected to a first resistor or capacitor (Ra1 to Ra3
or Ca1 to Ca3) and the second diode (Db1 to D
b3) connected in series, each connected between the second electrode of each first diode (Da1 to Da3) and the other end of the voltage source (1), and a plurality of second series circuits in which each second diode (Db1 to Db3) has a directionality such that the forward current of the second diode (Db1 to Db3) flows based on the sawtooth wave; , a plurality of second resistors or capacitors (Rb1 to Rb1 to Rb2) connected between the second electrode of each of the first diodes (Da1 to Da3) and the other end of the voltage source (1);
Rb3 or Cb1 to Cb3), the connection point (P_
A plurality of circuit elements to be scanned (S_1 to S
_3), the common current output line (2) and the voltage source (1
), and a common current-voltage conversion circuit (3) connected between the other end of the current-voltage conversion circuit (3) or the circuit elements (S_1 to S_3) to be scanned by controlling the output of the current-voltage conversion circuit (3) or the output of the current-voltage conversion circuit (3). A signal processing circuit for obtaining a read output and the connection point (P_
a plurality of timing detection differentiating circuits (F_1 to F_3) connected to the differentiating circuits (F_1 to F_3), respectively; and a control signal forming unit for forming a signal for controlling the signal processing circuit based on the output of the differentiating circuits (F_1 to F_3). A scanning circuit device comprising a circuit (5). [2] A circuit in which a voltage source (1) for supplying a sawtooth wave and a plurality of first diodes (Da1 to Da3) each having a first electrode and a second electrode are connected in series. one end of which is connected to the voltage source (1),
In addition, each of the first diodes (Da1 to Da3) has a directionality such that the forward current of each of the first diodes (Da1 to Da3) flows based on the sawtooth wave.
has, and each first diode (Da1 to D
a3) a first series circuit in which the first electrode is placed on the side of the voltage source (1), each connected to a capacitor (C1 to C3) and a first resistor (R
1 to R3) connected in series), each connected between the second electrode of each first diode (Da1 to Da3) and the other end of the voltage source (1). a plurality of second series circuits each connected between the second electrode of each first diode (Da1 to Da3) and the other end of the voltage source (1); resistors (Rb1 to Rb3), the capacitors (C1 to C3), and the first resistor (R1
A plurality of circuit elements (S_1 to S_3) to be scanned are respectively connected between the connection points (P_1 to P_3) with the common current output line (2) and the common current output line (2). ) and the other end of the voltage source (1); and a common current-voltage conversion circuit (3) or a circuit element to be scanned by controlling the output of the current-voltage conversion circuit (3). A signal processing circuit for obtaining read outputs of (S_1 to S_3) and the connection point (P_
Differentiating circuits (F_1 to F_3) for timing detection connected to the differentiating circuits (F_1 to F_3) respectively connected to the differentiating circuits (F_1 to F_3)
A scanning circuit device comprising a control signal forming circuit (5) that forms a signal for controlling the signal processing circuit based on the output of F_3).