JPH09121306A - Ccd drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a CCD drive with which it is not necessary to redesign a horizontal CCD pulse output buffer or a reset gate pulse output buffer for each desired characteristics of a solid-state imaging device and voltage drop at a part of respective pulses can be easily dealt with as well. SOLUTION: This device is provided with a first voltage operating part 5, to which a first power source voltage is supplied, for outputting 1st pulses H1 and H2 and a pulse P for another to be applied to an area image sensor for horizontally transferring electric charges on the area image sensor and a second voltage operating part 6, to which a second power source voltage is supplied, for outputting 2nd pulses H1' and H2' having the same cycle and phase as the 1st pulses and a pulse R to be applied to the reset gate of a charge detection part at the area image sensor. When outputting the 1st pulses H1 and H2, the outputs of the 2nd pulses H1' and H2' are stopped and when outputting the 2nd pulses, the outputs of 1st pulses are stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device (LSI) for generating CCD drive pulses.

[0002]

2. Description of the Related Art In recent years, the voltage of LSIs has been reduced to reduce the power consumption of video cameras and to prevent unwanted radiation. For example, many LSIs that were driven by a power supply voltage of 5V have been replaced by those that can be driven by a low voltage of 3V. However, lowering the driving voltage of the solid-state image sensor is not possible with other LS.
It's behind I.

A conventional video camera, as shown in FIG.
Solid-state image sensor 1, CCD driving LSI 2, signal processing unit 3,
The horizontal driver 4 etc. are provided. When the power supply voltage of the CCD driving LSI 2 is 5V, the horizontal CCD of the solid-state image sensor 1
The reset gate and the reset gate could be directly driven by the CCD driving LSI 2, but they could not be directly driven as the voltage of each LSI was lowered. Therefore, the CCD drive pulse generation LSI 2 and the solid-state image sensor 1 which operate at a low voltage
A horizontal driver 4 for converting a voltage from a low voltage to a CCD driving voltage is provided between the and.

The need for the horizontal driver 4 as described above is disadvantageous in terms of the number of parts and the cost. Therefore, FIG.
As shown in, the CCD drive LSI 2 has two power sources (V
DD1, VDD2) prepared, CCD drive pulses H1, H
The pulses P other than 2 are output as they are with a low voltage (VDD1, about 3 V) amplitude, while the CCD drive pulses H1 and H2 are output by the CCD using the level shifter inside the LSI.
It is also performed that the level is shifted to the amplitude of the power supply voltage (about 5 V) required for driving and then output. That is, CCD
By changing the voltage of the output buffer between the drive pulse and the LSI pulse of the signal processing unit 3, the number of parts for voltage conversion is reduced.

[0005]

The above-mentioned structure is not a problem when the voltages of the horizontal CCD and the reset gate of the solid-state image pickup device have the same value, but generally, lowering the voltage of the reset gate reduces the solid-state image pickup device. This is difficult because it has a large effect on the characteristics of (1), and it is necessary to change the drive voltage between the horizontal CCD and the reset gate pulse according to the desired characteristics.

Therefore, according to the present invention, it is not necessary to redesign the horizontal CCD pulse output buffer or the reset gate pulse output buffer for each desired characteristic of the solid-state image pickup element, and it is possible to reduce the voltage of a part of each pulse. It is an object of the present invention to provide a CCD drive device (LSI) which can be easily dealt with.

[0007]

In order to achieve the above object, the CCD driving device according to the first aspect of the present invention is provided with a first CCD driving device.
A first voltage operating unit, which is supplied with a power supply voltage and outputs a first pulse applied to the area image sensor to transfer charges on the area image sensor in the horizontal direction and a pulse for another device, and a second power supply A voltage is applied to the first
A second voltage operation unit that outputs a second pulse having the same period and phase as the pulse and a pulse applied to the reset gate of the charge detection unit of the area image sensor is provided.
Further, when it is configured to stop the output of the second pulse when outputting the first pulse and stop the output of the first pulse when outputting the second pulse, power consumption and It is preferable for reducing unnecessary radiation.

The CCD drive device according to the second configuration is the first
A drive pulse supplied to the area image sensor to supply charges on the area image sensor in the horizontal direction, a reset pulse applied to a reset gate of a charge detection unit of the area image sensor, and the like. A first voltage operation unit that outputs the device pulse, and a second voltage operation unit that is supplied with the second power supply voltage and has the same number of voltage conversion buffers as the number of the drive pulses and the reset pulses. .

The CCD drive device according to the third configuration is the first
A first power supply operating unit that is supplied with a power supply voltage and outputs a pulse applied to the area image sensor to transfer charges on the area image sensor in the horizontal direction; and a second power supply voltage is supplied, and the area image sensor A second power supply operating unit that outputs a pulse applied to the reset gate of the charge detecting unit and a third power supply operating unit that is supplied with a third power supply voltage and outputs a pulse for another device.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a conceptual diagram of a CCD drive device (hereinafter referred to as “CCD drive LSI”) according to the first embodiment. This CCD driving LSI includes a first voltage operating unit 5 to which a first power supply voltage (VDD1) is supplied and a second voltage operating unit 6 to which a second power supply voltage (VDD2) is supplied.
Consists of A horizontal CCD drive pulse (H1, H2) and a pulse to another LSI are output from the first voltage operating unit 5, and another horizontal CC is output from the second voltage (VDD2) operating unit 6.
The D drive pulse (H1 ′, H2 ′) and the reset gate pulse (R) are output. Therefore, other LSI pulses are output at the first voltage, reset gate pulses are output at the second voltage, and horizontal CCD pulses are output at the first and second voltages.
It is output at both voltages.

To output all output pulses at 5V,
It is sufficient to supply 5 V for both the first and second power supply voltages. When the horizontal CCD pulse and the reset gate pulse are 5 V and the other LSI pulses are 3 V, the first power supply voltage is 3 V and the second power supply voltage is 5 V, and the second voltage outputs H1 'and H2' are horizontal CCD drive pulses. Should be used. If only the reset gate pulse is 5V and the other pulses are 3V,
The first power supply voltage is 3V, the second power supply voltage is 5V, and the horizontal C
The first voltage outputs H1 and H2 may be used as the CD drive pulse. When the output pulses are all 3V, both the first and second voltages may be set to 3V, and the horizontal CCD drive pulse may use either the first or second voltage output.

Further, by providing a switch for stopping the output of the two horizontal CCD drive pulse outputs on the unused side, it is possible to reduce power consumption and unnecessary radiation.

Next, a CCD drive L according to the second embodiment
The conceptual diagram of SI is shown in FIG. This CCD drive LSI
It comprises a first voltage operating unit 7 supplied with a first power supply voltage (VDD1) and a second voltage operating unit 8 supplied with a second power supply voltage (VDD2). Horizontal CCD from the first voltage operating unit 7
A drive pulse (H1, H2), a reset gate pulse (R), and a pulse to another LSI are output. Second
The voltage operating unit 8 is provided with three systems of buffers 12 including level shifters for boosting.

In order to output all output pulses at 5V using this CCD driving LSI, the first power supply voltage may be set to 5V. In this case, the second voltage operating unit 8 (buffer 1
2) need not be used. Horizontal CCD pulse and reset gate pulse are 5V, other LSI pulses are 3V
In this case, the first power supply voltage is 3 V, the second power supply voltage is 5 V, and the horizontal CCD pulse (H1,
2) and the reset gate pulse (R) are input to the second voltage operation unit 8 (buffer 12). Then, the level-shifted 5V output (H1 ′, H2 ′, R ′) is obtained. When only the reset gate pulse is 5V and the other pulses are 3V, the first power supply voltage is 3V and the second power supply voltage is 5V.
Only the reset gate pulse obtained as V output is second
It is input to the voltage operating unit 8 (buffer 12) and a 5V output (R ') is obtained. When all the output pulses are 3V, the first power supply voltage is set to 3V, and the second voltage operating unit 8 (buffer 1
2) is not used.

Next, a CCD drive L according to the third embodiment
A conceptual diagram of SI is shown in FIG. This CCD drive LSI
The first voltage operating unit 9 supplied with the first power supply voltage (VDD1), the second voltage operating unit 10 supplied with the second power supply voltage (VDD2), and the third supplied with the third power supply voltage (VDD3).
And a voltage operating unit 11. The first voltage operation unit 9 outputs a pulse to another LSI, and the second voltage operation unit 10 outputs a horizontal CCD drive pulse (H1, H2).
Reset gate pulse (R) from the third voltage operating unit 11
Is output.

Since this CCD driving LSI can supply the first, second and third power supply voltages corresponding to the horizontal CCD pulse, the reset gate pulse and the other LSI pulse, respectively, It is possible to set three types of power supply voltages according to voltage conditions.

In the above embodiment, the normal power supply voltage is 5
Although the description has been made assuming that the V and the low voltage are 3V, other combinations of voltage values may be used. Further, the present invention can be applied not only to the case where the high voltage side pulse output from the CCD drive device drives only the CCD, but also to the case where another LSI such as a bipolar IC is driven.

[0018]

As described above, according to the CCD driving device (LSI) of the present invention, it is possible to output a pulse of a plurality of voltage types including a pulse for a solid-state image pickup device without the need for a level shift IC. In addition, it is possible to cope with various combinations of each pulse and output voltage. Therefore, it is possible to easily cope with a reduction in the voltage of a part of each pulse.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a CCD driving device according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of a CCD driving device according to a second embodiment.

FIG. 3 is a conceptual diagram of a CCD driving device according to a third embodiment.

FIG. 4 is a block diagram of a conventional video camera.

FIG. 5 is a conceptual diagram of a CCD driving device in a conventional video camera.

[Explanation of symbols]

 1 Solid-state imaging device 2 CCD drive LSI 3 Signal processing unit 4 Horizontal driver 5, 7, 9 First voltage operating unit 6, 8, 10 Second voltage operating unit 11 Third voltage operating unit

Claims (4)

[Claims] 1. A first voltage supplied with a first power supply voltage and outputting a first pulse applied to the area image sensor for horizontally transferring charges on the area image sensor and a pulse for another device. An operating unit and a second voltage operation for supplying a second power supply voltage and outputting a second pulse having the same period and phase as the first pulse and a pulse applied to a reset gate of a charge detection unit of the area image sensor. And a CCD drive device. 2. The C according to claim 1, wherein the output of the second pulse is stopped when the first pulse is output, and the output of the first pulse is stopped when the second pulse is output.
CD drive. 3. A drive pulse applied to the area image sensor to transfer charges on the area image sensor in the horizontal direction when supplied with a first power supply voltage, and applied to a reset gate of a charge detection unit of the area image sensor. A first voltage operation unit for outputting a reset pulse and a pulse for another device, and a second voltage supplied with a second power supply voltage and having a voltage conversion buffer of the same number as the number of the drive pulse and the reset pulse. CCD with operating part
Drive. 4. A first power supply operating unit, which is supplied with a first power supply voltage and outputs a pulse applied to the area image sensor to transfer charges on the area image sensor in a horizontal direction, and a second power supply voltage. A second power supply operation unit that outputs a pulse that is supplied and is applied to the reset gate of the charge detection unit of the area image sensor, and a third power supply operation unit that is supplied with a third power supply voltage and outputs a pulse for another device. And a CCD drive device.