JPH02210948A - Sensor chip and photoelectric converter using same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sensor chip and a photoelectric conversion device using the sensor chip, and particularly to a multi-chip photoelectric conversion device formed by arranging a plurality of sensor chips.

[Prior art and problems to be solved by the invention] Conventionally,
2. Description of the Related Art Photoelectric conversion devices (linear image sensors) in which light-receiving elements are arranged in a line are often used in image reading devices such as facsimile machines.

Since the sensor chip of a linear image sensor is made from a silicon wafer, the sensor length is limited by the wafer size, and it is difficult to make a linear image sensor chip with the same length as the width of the original to be read. For this reason, an imaging optical system is used to form a reduced image of the original to be read, and the mutually compatible images of the original are read. However, devices that utilize such a reduction imaging optical system require space for the optical system, making it difficult to downsize and also difficult to achieve sufficient resolution.

Therefore, so-called multi-chip image sensors, in which a plurality of linear image sensor chips are arranged in a straight line, have come to be used.

FIG. 5 is a schematic diagram showing an example of the conventional multi-chip image sensor.

In the figure, 1-1 is a sensor chip, and this chip includes n light receiving elements 2-1-1 arranged in a row in the X direction.
~2-1-n are formed.

The depth 1-1 also includes light receiving elements 2-1-1 to 2.
A selection circuit 3-1 is formed which sequentially selects the outputs of -1-n. The chip 1-1 also includes the selection circuit 3.
An amplifier 4-1 is formed to amplify the output of -1,
The output of the amplifier is output from the chip through an output line 5-1.

The selection circuit 3-1 is driven by an external drive circuit via an input line 8-1.

1-2 to 1-m are sensor chips having the same configuration as the above-mentioned sensor chip 1-1, and corresponding parts are given corresponding symbols.

The sensor chips l-1 to 1-m are arranged in one row in the X direction, so that all (nXm) light receiving elements are arranged in one row in the X direction.
It will be arranged in columns.

When reading an image, the document carrying the gunshot image is conveyed in the y direction relative to the photoelectric conversion device while facing the light receiving element.

The output from the entire light receiving fill of chip 1-1 is sent to the selection circuit 3.
-1 are sequentially selected and output from the output line 5-1 to the outside, and then outputs from all light receiving elements of the chip 1-2 are sequentially selected by the selection circuit 3-2 and output from the output line 5-2 to the outside. Thereafter, signals are sequentially read out from the light receiving elements in the same manner, and eventually the outputs of all the light receiving elements are outputted in time series.

However, in the conventional multi-chip image sensor as described above, the amplifier is in operation even when the light-receiving element of each chip is not outputting a signal to the outside of the sensor chip. When the number increases, there are problems such as an unnecessary increase in power consumption and a deterioration of the lasensor characteristics as the chip temperature rises due to heat generation.

In view of the above-mentioned prior art, the present invention provides a photoelectric conversion device that reduces power consumption of a multi-chip photoelectric conversion device and prevents sensor characteristics from deteriorating due to temperature rise due to heat generation, and a sensor chip that constitutes the photoelectric conversion device. The purpose is to provide

[Means to solve the problem] According to the invention, the above objectives are achieved.

In a sensor chip used in a multi-chip photoelectric conversion device in which a plurality of sensor chips having a plurality of light-receiving elements are arranged, the sensor chip includes an amplifier that amplifies the output signal from the light-receiving element of the sensor chip, and an amplifier that amplifies the output signal from the light-receiving element of the sensor chip, and A sensor chip, characterized in that it has a control circuit that keeps the amplifier in an operating state only during a period that includes the time for outputting a signal from an element to the outside of the sensor chip, and that makes the amplifier in an inactive state outside of the period. achieved.

In the sensor chip of the present invention, the light receiving element may be of a type that accumulates photoexcited carriers in the control electrode region of the transistor.

Furthermore, the sensor chip of the present invention is provided with a selection circuit that sequentially selects the output signals from each light-receiving element and inputs them to a common amplifier, and the control circuit is operated by the signal from the selection circuit. can do.

Further, in the sensor chip of the present invention, the start time of the above-mentioned period can be set to be slightly before the time when the first signal output from the light receiving element to the outside of the sensor chip is actually started.

According to the present invention, the above object is to amplify an output signal from the light receiving element in each sensor chip in a multi-chip photoelectric conversion device formed by arranging a plurality of sensor chips each having a plurality of light receiving elements. An amplifier is provided to receive light for each sensor chip. The sensor chip is characterized in that a control circuit is provided in the sensor chip to keep the amplifier in operation only during a period including the time when a signal is output from the sensor chip to the outside of the sensor chip, and to make the amplifier 4111 inactive outside of the above period. shall be. Photoelectric conversion device.

This is achieved by

In the photoelectric conversion device of the present invention, a plurality of light-receiving elements are arranged in a straight line in each sensor chip, and the sensor chips can be arranged along the direction in which the light-receiving elements are arranged.

[Example] Hereinafter, specific examples of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing a first embodiment of a photoelectric conversion device of the present invention.

In the figure, 1-1 is a sensor chip, and the chip is made of a semiconductor such as silicon. The chip includes n light receiving elements 2-1- arranged in a row in the X direction.
1 to 2-1-n are formed. The light-receiving element is of a type in which photo-excited carriers are accumulated in the control electrode region of the transistor and an output corresponding to the accumulated charges is outputted at an appropriate time. In addition, each light receiving element 2-1-1 to 2-1 is attached to the chip l-1.
A selection circuit 3-1 is formed which sequentially selects the -n outputs. The chip l-1 also includes the selection circuit 3-1.
An amplifier 4-1 is formed to amplify the output of the amplifier 4-1, and the output of the amplifier is output from the output line 5-1 to the outside of the chip.

In this embodiment, a control circuit 6-1 is formed in the chip t-i to output a control signal for switching between an operating state and a non-operating state to the amplifier 4-1. The control circuit is driven by an external drive circuit via input line 7-1. Also,
The selection circuit 3-1 is also driven by an external drive circuit via the input MA8-1.

1-2 to 1-m are sensor chips having the same configuration as 1-1, and corresponding parts are given corresponding symbols.

The sensor chips l-1 to 1-m are arranged in one row in the X direction, and therefore all (n x m) light receiving elements are arranged in one row in the X direction.

All sensor chips are arranged and fixed on a base (not shown). and,! ! When reading an i-image, the document carrying the read image is conveyed in the X direction relative to the photoelectric conversion device while facing the light receiving element.Next, the operation of this embodiment will be described.

FIG. 2 is a timing diagram for explaining an example of the operation of the above embodiment.

In the figure, φL represents the output control signal of the control circuit 6-1 in the sensor chip 1-1, φ2 represents the output control signal of the control circuit 6-2 in the sensor chip 1-2, and V out IVout2 are each sensor chips! -1 output of amplifier 4-1 and sensor chip 1
-2 amplifier 4-2 is shown.

The above φ1 is the selection circuit 3- driven by the input line 8-1.
In other words, the output of φ1 is synchronized with the operation of the amplifier 4-1 only during a specific period including the time when the outputs from all the light-receiving elements of the chip l-1 are sequentially selected by the selection circuit. is in the operating state, and there is an output of Voutl. Of course, the sensor chip l-
Contains outputs from all light-receiving elements of 1.

Similarly, φ2 is synchronized with the operation of the selection circuit 3-2 driven by the input line 8-2, that is, the time during which the outputs from all the light-receiving elements of chip l-2 are sequentially selected by the selection circuit. There is an output of φ2 only during a specific period including V Out
There are 2 outputs. Of course, the output of Vout2 includes all the light received by sensor chip l-2! Contains output from the source.

As shown in FIG. 2, the start time of the period φ2 in E-book is the same as the end time of the period φ1.

Thereafter, in the same manner, the third and subsequent sensor chips 1-
The output control signals of the control circuits 6-3 to B-m in the control circuits 6-3 to 1-m are issued.

In the manner described above, signals are sequentially read out from the light-receiving elements, and the outputs of all the light-receiving elements are eventually output in time series.

In this example, for each sensor chip, the kPj amplitude amplifier is in the operating state only during the period tlff, which is approximately the same as the time when the signal is output from the light receiving element, and the amplifier is in the non-operating state in periods other than this period. Therefore, the total amplifier 4
The power consumption for -1 to 4-m can be the conventional l/m.

FIG. 3 is a timing diagram for explaining another example of the operation of the above embodiment. In this figure, the same reference numerals as in FIG. 2 are used.

In this example, as shown in Figure 1, the control signal φJ for the first sensor chip and the control signal φ2 for the second sensor chip overlap for a time t. Then, φ1 and φ2 are brought into operation a little # (before time t) when the first light-receiving element is selected by the selection circuit in each sensor chip. The same applies to the 38th and subsequent sensor chips.

In this way, by starting each control signal at a timing slightly before the reading of the first light receiving element of each sensor chip,
It is possible to secure time for each amplifier to start operating and stabilize, and it is possible to output signals from all light receiving elements including the first selected light receiving element in each sensor chip with good accuracy. Furthermore, since the time for the control signals to overlap at this time is sufficiently small in terms of the overall time, the increase in power consumption is extremely small even in the example shown in FIG. 2 above.

FIG. 1 is a schematic configuration diagram showing a second embodiment of the photoelectric conversion device of the present invention. In this figure, the same members as in FIG. 1 are given the same reference numerals.

In this embodiment, each sensor chip has a control circuit e-t~
The second embodiment is the same as the first embodiment except that the selection circuits 6-m are controlled by control signals from the selection circuits 3-1 to 3-m, respectively.

That is, the selection circuits 3-1 to 3- are selected from the input lines 8-1 to 8-m.
A signal is given from the selection circuit to the control circuit corresponding to the time when an operation command signal for sequentially selecting the outputs from all the light-receiving elements of each chip is input for m, and thereby the first embodiment described above is achieved. Switching control between the operating state and the non-operating state of the amplifier is performed in the same manner.

According to this embodiment, compared to the first embodiment described above.

Switching between the operating state and non-operating state of the amplifier can be automatically set, there is no need to use an external drive circuit with an output for #IIdIa, and furthermore, as in the first embodiment, the control circuit of each chip can be controlled from the external drive circuit. For wiring 7-1 to 7-r
Since there is no need to provide n, the external circuit is simplified.

[Effects of the Invention] As explained above, according to the present invention, there is a significant effect in reducing power consumption in a multi-chip photoelectric conversion device without providing a special circuit externally, and furthermore, the power consumption can be reduced. This has the effect of reducing heat generation caused by the oxidation process and preventing deterioration of characteristics.

[Brief explanation of the drawing]

Figure 1 shows the photoelectric transformer of the present invention! 1 is a schematic configuration diagram showing a first example of an II device; FIG. FIG. 2 is a timing diagram for explaining an example of the operation of the above embodiment. FIG. 3 is a timing diagram for explaining an example of the operation of the above embodiment. FIG. 4 is a schematic configuration diagram showing a second embodiment of the photoelectric conversion device of the present invention. FIG. 5 is a schematic diagram showing an example of the conventional multi-chip image sensor. l-1-1-m: sensor chip, 2-1-1 to 2-m-n: light receiving element. 3-1 to 3-m: selection circuit, 4-1 to 4-m: *@ device, 8-1 to 6-m: control circuit. Agent Patent Attorney Seki Yamashita Out 2 --- 11 pressure pressure 1 plate■-

Claims (6)

[Claims] (1) In a sensor chip used in a multi-chip photoelectric conversion device formed by arranging a plurality of sensor chips each having a plurality of light-receiving elements, the sensor chip includes an amplifier that amplifies the output signal from the light-receiving element of the sensor chip. and a control circuit that keeps the amplifier in an operating state only during a period that includes the time for outputting a signal from the light-receiving element to the outside of the sensor chip, and keeps the amplifier in an inoperable state outside of the period. Chip. (2) The sensor chip according to claim 1, wherein the light receiving element is of a type that accumulates photoexcited carriers in a control electrode region of a transistor. (3) The sensor according to claim 1, further comprising a selection circuit that sequentially selects the output signal from each light-receiving element and inputs it to a common amplifier, and the control circuit is operated by the signal from the selection circuit. Chip. (4) The sensor chip according to claim 1, wherein the start time of the period is slightly before the time when the light receiving element actually starts outputting a first signal to the outside of the sensor chip. (5) In a multi-chip photoelectric conversion device formed by arranging a plurality of sensor chips each having a plurality of light-receiving elements,
Each sensor chip is provided with an amplifier that amplifies the output signal from the light-receiving element, and for each sensor chip, the amplifier is activated only during the period that includes the time for outputting the signal from the light-receiving element to the outside of the sensor chip. A photoelectric conversion device characterized in that a control circuit for putting the amplifier in a non-operating state is provided in a sensor chip. (6) The photoelectric conversion device according to claim 5, wherein a plurality of light receiving elements are arranged in a straight line in each sensor chip, and the sensor chips are arranged along the arrangement direction of the light receiving elements.