JPS63232761A - Signal transferring device - Google Patents

Abstract

PURPOSE:To execute the high speed transfer without reducing a signal level by providing an amplifier between a switch means and a signal line, driving directly the signal line with an amplifier and decreasing the capacity of the signal line. CONSTITUTION:An amplifier 101 is provided between a switch means Qsr and a signal line 2. The output signal of a sensor 1 accumulated once in a capacitor Ct is inputted through a scanning transistor Qsr to constitute a switch means to a buffer amplifier 101. The buffer amplifier 101 drives a capacity Ch of the signal line 2. Thus, since the signal line 2 is directly driven by the buffer amplifier 101, the high speed transfer can be executed for a sensor signal without reducing the level.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a signal transfer device that transfers a plurality of signals to a signal line via a switch means.

[Prior art and its problems] The case of a high-density line sensor will be described below as an example.

When sensors are arranged in high density, the capacitance of signal lines increases, causing various problems in reading signals from each sensor.

FIGS. 7A to 7C are schematic circuit diagrams showing conventional examples of signal transfer devices, respectively.

In FIG. 3A, the transfer transistor Qt is turned on, the scanning transistor Qsr is turned off, and the output signal of the sensor 1 is temporarily stored in the capacitor Ct. Then, the transfer transistor Qt is turned off, and the scanning transistor QSr is turned off.
When the capacitor CL is turned on, the signal from the capacitor CL is taken out as a signal kQ2 and outputted to the outside through the output amplifier 3. In this case, if the capacitance of signal line 2 is ch, the signal is Ct/(
The level decreases in proportion to Ct+ch).

In particular, when the density is increased and the number of scanning transistors Qsr increases, the capacitance Ch of the signal line 2 also increases, and the signal level decreases significantly.

As a countermeasure for this, increasing Ct can be considered,
This will increase the layout area of Ct, causing problems such as an increase in chip size and a decrease in yield.
Ru.

The circuit shown in the same figure (B) directly receives the output signal of sensor 1.
A method is adopted in which the signal is taken out to signal line 0 line 2.

This method has a capacity of 7. Since there is no Ict, the signal line capacitance c
There is no level drop between h and h.

However, since the sensor size is reduced due to high density, it takes time to drive a large capacitance channel, and high-speed scanning is not possible.

The circuit shown in FIG. 3(C) is an improved version of the circuit shown in FIG. 2(B). That is, the output signal of the sensor 1 is passed through the amplifier 4, and the amplifier 4 drives the signal line 2 having a large capacity. For example, the sensor 1 and the amplifier 4 may include bipolar transistors connected in a Darlington connection. The scanning speed in this case is
It is determined by a time constant consisting of the ON resistance Ron of the scanning transistor Qsr and the capacitance ch.

However, the main thing about signal &1ij2's capacity ff1ch is:
This is the total amount of drain capacitance of the scanning transistor Qsr connected to the signal line 2. Therefore, the time constant Ron・c
In order to reduce h, there is no point in increasing the channel width of the transistor Qsr, and it is necessary to reduce the channel length.

However, there are limitations in reducing the channel length due to the characteristics of MOS transistors and in terms of manufacturing, and therefore there are also limitations to high-speed scanning speed.

[Means for Solving the Problems] A signal transfer device according to the present invention is a signal transfer device that transfers a plurality of signals to a signal line via a switch means, and includes an amplifier between the switch means and the signal line. It is characterized by having been established.

[Function] By providing an amplifier between the L-sinch means and the signal line, the signal line can be directly driven by the amplifier, so high-speed transfer is possible without lowering the signal level.

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

FIGS. 1A and 1B are schematic diagrams of a first and fJS2 embodiment of a signal transfer device according to the invention, respectively.

In FIG. 1(A), the sensor signal once stored in the capacitor Ct is input to the buffer amplifier 101 through the scanning transistor Qsr. and buffer amplifier 1
01 drives the capacitor channel of the signal line 2.

In this way, in order for the buffer amplifier 101 to directly drive the capacitor channel, the senna signal is used as the signal! ! 2 can be transferred at high speed, and there is no drop in signal level.

FIG. 1(B) shows the configuration of a system in which the sensor signal is directly read out. The sensor signal is directly input to the buffer amplifier 101 through the scanning transistor Qsr, and the capacitance channel of the signal line 2 is driven by the buffer amplifier 101. Ru.

FIG. 2 is a circuit diagram of a line sensor that is a specific configuration example of the first embodiment of the present invention.

As shown in the figure, the optical sensors C11 to Cn are arranged in a line and are operated by inputting a drive pulse φr.

The output signal of each optical sensor is stored in a capacitor Ct through a transfer transistor Qt, and is further inputted into a base electrode of an amplifier IO1 made of a bipolar transistor through a scanning transistor Qsr. A transfer pulse φt is input to the gate electrode of the transfer transistor Qt.

A constant positive voltage is applied to the collector electrode of the amplifier 101, and the emitter electrode is commonly connected to the signal line 2. As described above, the signal line 2 has a capacitor channel. The signal line 2 is grounded via the reset transistor Qhrs, and is also connected to the input terminal of the output amplifier 3.

Further, the base electrode of each amplifier 101 is grounded via the reset transistor Qhr, and the transistor Qhr
A reset pulse φhrs is input to the gate electrode of the transistor Qhrs and the gate electrode of the transistor Qhrs.

A scanning circuit 1 is connected to the gate electrode of the scanning transistor Qsr.
Scanning pulses φ11 to φ1n are input from 02, respectively.
The scanning circuit 102 receives the start pulse φS and outputs a scanning pulse in synchronization with the drive pulse φ1.

Further, in order to reset the optical sensors C1 to Cn and each capacitor Ct, a transistor Qvrs is provided, and a pulse φvrs is commonly input to its gate electrode.

FIG. 3 is a timing chart showing an example of the operation of the line sensor. First, pulse φ and φvrs are set to high level to turn on transistors Qt and Qvrs and reset capacitor Ct (Ct reset period).

Subsequently, the transistor Qvrs is turned off while the transistor Qt remains on, and the drive pulse φr is set to a high level. As a result, the signals of the optical sensors C1 to Cn are transferred and accumulated in each capacitor Ct (signal transfer period)
.

Next, while applying the drive pulse φr, the transistor Qt is turned off and the transistor Qvrs is turned on to reset each optical sensor (sensor reset period). When this reset is completed, each optical sensor performs a photoelectric conversion operation. The charge accumulation operation is started, and in parallel with this, the signal accumulated in the capacitor Ct is scanned.

The mass pulse φhrs is set to low level and the transistor Q
hr and Qhrs are turned off, and the scanning pulse φ11 is output from the scanning circuit 102.

As a result, the signal from the photosensor C1 stored in the capacitor Ct is input to the amplifier 101 through the scanning transistor Qsr, amplified, taken out to the signal line 2, and outputted to the outside as a signal Vout through the output amplifier 3. Next, 5. < Set the pulse φhrs to high level, turn on the transistors Qhr and Qhrs, and turn on the amplifier 10.
1 base and signal line 2.

Similarly, scanning pulses φ12 and φ are sent from the scanning circuit 102.
By sequentially outputting signals 1i, . . . -φ1n, the signals of the optical sensors C2, c3'', .

Since the signal line 2 is driven by the amplifier 101 in this way, high-speed transfer of two signals is possible even if the sensors are arranged at high density and the capacity of the signal line 2 becomes large.

FIG. 4 is a circuit diagram of a line sensor that is a specific configuration example of the second embodiment of the present invention.

In the figure, scanning circuit 103 receives start pulse φS and sequentially outputs scanning pulses φ11 and φ21 to φ1n and φ2n, respectively, in synchronization with pulses φ1 and φ2. By outputting each scanning pulse, the corresponding optical sensor is driven, and the corresponding scanning transistor Qsr is turned on to transfer signals.

Further, the photosensor is reset through the transistor Qrs at the timing of the pulse φrs.

The configuration of the transistor Qhr, amplifier 101, signal line 2, etc. is the same as that shown in FIG.

FIG. 5 is a timing chart showing an example of the operation of the line sensor.

The mass pulse φrs is set to low level and the transistor Qr
s, Qhr, and Qhrs are turned off, and a scanning pulse φ11 is output in synchronization with the pulse φ1.

As a result, the optical sensor C1 is driven, the scanning transistor Qsr is turned on, and the signal from the optical sensor C1 is input to the amplifier 101 through the transistor Qsr, amplified, and taken out to the signal line 2. And output amplifier 3
The signal Vout is output to the outside as a signal Vout (transfer period).

Next, while keeping the scanning pulse φ11 at high level,
Pulse φrs is set to high level, transistor Qrs,
Turning Qhr and Qhrs ON=This resets the optical sensor cl and the signal line 2. Note that in this case, the transistor Qhr can also be omitted.

Similarly, each signal from the optical sensors C2 to C2n is sequentially taken out to the signal line 2 through the amplifier 101 by the scanning pulse from the scanning circuit 103, and output to the outside.

On the wood flow side, the optical sensor signal is directly sent to the amplifier 101.
There is no reduction in signal level due to input, and higher output and higher speed operation can be achieved than in the first embodiment.

Next, as an example of the optical sensor used in each of the above embodiments, a photoelectric conversion device basically described in Japanese Patent Application No. 120751/1982 will be shown.

FIG. 6(A) is a basic drive circuit diagram of the optical sensor.
Figure (B) is a timing chart for explaining the operation.

In FIG. 6(A), the optical sensor C is composed of a bipolar transistor and a capacitor Cox for controlling the base potential of the bipolar transistor. Then, carriers excited by the incident light are accumulated in the base of the bipolar transistor, thereby performing a photoelectric conversion operation.

A positive voltage driving pulse φ is applied to the capacitor electrode of the optical sensor C.
r is input, and the emitter electrode is connected to JaJlb through the transistor Qvrs. A pulse, φvrs, is input to the gate electrode of the transistor Qvrs. Further, a temporary storage capacitor Ct is connected to the emitter electrode.

In such a configuration, by applying a pulse at the timing shown in the same figure (B), the optical sensor can be reset,
Performs storage and read operations.

First, the transistor Qvrs is turned off by the pulse φvrs.
When the emitter electrode of the photosensor C is grounded and a pulse φr is input to the capacitor electrode, the bipolar transistor operates and the carriers accumulated in the base are removed (reset operation).

Subsequently, after carrying out a carrier accumulation operation corresponding to the incident light, the emitter side is placed in a floating state and a pulse φr is applied. This causes the bipolar transistor to operate, and the base storage voltage is read out to the emitter side (read operation) and temporarily stored in the capacitor Ct.

Note that the optical sensor is not limited to such a base accumulation type, and may be of other types such as an electrostatic induction type.

Further, the one-piece invention is not limited to the above-mentioned embodiments, but can be applied to general circuits that scan and drive and transfer a large number of signals.

[Effects of the Invention] As explained in detail above, the signal transfer device according to the present invention provides the amplifier between the switch means and the signal line, so that the signal line can be directly driven by the amplifier, and the signal line can be directly driven by the amplifier. Since the capacity can be reduced, high-speed transfer can be achieved without reducing the signal level.

[Brief explanation of drawings]

FIGS. 1A and 1B are schematic diagrams of the first and second embodiments of the signal transfer device according to the present invention, respectively.
A circuit diagram of a line sensor that is a specific configuration example of the first embodiment of the present invention; FIG. 3 is a timing chart showing an operation example of the line sensor; FIG. 4 is a specific configuration example of the second embodiment of the present invention FIG. 3 is a circuit diagram of a line sensor that is an example of a configuration. FIG. 5 is a timing chart showing an example of the operation of the line sensor, FIG. 6(A) is a basic drive circuit diagram of the optical sensor, and FIG.
FIG. 7(B) is a timing chart for explaining its operation, and FIGS. 7(A) to 7(C) are schematic circuit diagrams showing conventional examples of signal transfer devices, respectively. l・11-Senna 2...Signal line 3...Reference output amplifier 101φ・Base amplifier 102.103...φ scanning circuit C1~Cneψ・Optical sensor ch...Signal line capacity agent Patent attorney Sekihei Yamashita Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 (A) Enemy (B) Tongue

Claims (1)

[Claims] (1) A signal transfer device for transferring a plurality of signals to a signal line via a switch means, characterized in that an amplifier is provided between the switch means and the signal line.