JP2007096601A - Imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging device which reduces power consumptions of a solid-state imaging element and a circuit processing its output image when there is not a subject in motion. <P>SOLUTION: Imaging light which arrives through an imaging lens 101 and corresponds to a subject is supplied to a CCD 102 and converted into an electric signal. The video signal converted by the CCD 102 into the electric signal is supplied to a signal processing circuit 103 to detect movements of an image, which are output to a microphone 106. The microcomputer 106 decides the degree of the movements and selects a driving clock to be supplied to the CCD 102, signal processing circuit 103, and a camera signal processing circuit 104. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging apparatus, and more particularly to an imaging apparatus capable of a power saving operation in accordance with the movement of a captured image.

  Conventionally, various proposals have been made on imaging devices using solid-state imaging elements. In these image pickup apparatuses, the operation of the solid-state image sensor is always driven to be constant, so that the power consumption is constant.

  In a surveillance camera system installed in a bank, a convenience store or the like that uses the above-described imaging device, it is general that a surveillance camera, a monitor, and a recording device (video tape recorder) are always operating. For this reason, these devices operate even for a lot of time that does not need to be monitored, resulting in a great consumption of power.

  However, in recent years, in order to save power and recording media, a light emitting device such as an infrared ray and a light receiving device are provided in advance in the monitored area, and monitoring is performed when a change in the situation such as intrusion of a suspicious person occurs. There have been proposed a system in which a monitoring system including a camera, a monitor, and a video tape recorder starts operation, and a system that includes a memory in a camera circuit and detects a moving object.

  However, as a means for detecting a suspicious person, a light emitting device such as an infrared ray and a light receiving device are provided in advance in the monitored area, and the surveillance camera system starts operating when a change in the situation such as the intrusion of a suspicious person occurs. In a system or a system that includes a memory in a camera circuit and detects a moving object, the system configuration becomes large, leading to an increase in cost. Furthermore, in a system having a memory, it is necessary to perform digital conversion in a black and white camera in which an analog system is mainstream, which increases the circuit scale for detection and is not practical.

  Therefore, it is possible to detect a moving object of the camera subject by amplifying a low gradation to intermediate gradation signal among the output signals of the solid-state imaging device and detecting a fluctuation component of the signal with a simple circuit configuration. Furthermore, while a moving subject is detected by controlling a commercially available timer IC, power is supplied to the camera and its system. If a subject that has moved for more than a set time is not detected, Power is supplied only to the power supply circuit for driving the image pickup device and the IC that drives the image pickup device and the power supply control unit according to the present invention, and power is not supplied to other signal processing circuits, monitors, and recording units. As a result, when there is no moving subject, that is, in a scene that does not need to be monitored, a surveillance camera system that is large and can reduce power consumption of the surveillance camera system without using a system that increases costs Has been proposed (see, for example, Patent Document 1).

JP 2000-207650 A

  By the way, in the proposal disclosed in Patent Document 1, it is described that the power consumption of the surveillance camera system is reduced, and the problem has been achieved. However, power is supplied to the solid-state imaging device. There has been a problem that the power consumption of the imaging apparatus has not been reduced.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an imaging apparatus capable of a power saving operation in accordance with the movement of a captured image.

In order to solve the above problems, the present invention comprises the following means.
That is,
An imaging device using a solid-state imaging device that photoelectrically converts a subject image formed by a photographing lens,
A timing generator for controlling the readout timing of the solid-state imaging device;
A signal processing circuit for converting a video image photoelectrically converted by the solid-state imaging device into a digital video signal;
A camera signal processing circuit for generating an imaging output video signal, comprising motion detection means for detecting motion information that is a degree of motion based on the digital video signal;
A microcomputer for determining the degree of movement of the imaging output video signal from the movement information;
The imaging apparatus is characterized in that the microcomputer supplies a drive clock having a frequency corresponding to the determined degree of movement to the timing generator, the signal processing circuit, and the camera signal processing circuit.

  According to the imaging apparatus of the present invention, the solid-state imaging element of the imaging apparatus and a circuit for processing the output image of the imaging apparatus are detected while detecting the movement of the subject from the output signal of the solid-state imaging element. By reducing the driving clock of the solid-state imaging device, the power consumption of the solid-state imaging device and the circuit for processing the output image is reduced. As a result, when there is no moving subject, there is an effect of providing an imaging device capable of reducing power consumption without using a large-scale and costly system.

  The best mode for carrying out the invention of the imaging apparatus according to the present invention will be described below with reference to preferred embodiments.

  FIG. 1 shows a main part of the configuration of an imaging apparatus applied to the present embodiment. A CCD is used as a solid-state imaging device. As shown in FIG. 1, the imaging apparatus 100 processes an image signal based on an imaging lens 101, a solid-state imaging device (CCD) 102 that converts an optical signal corresponding to a subject into an electrical signal, and an output signal of the CCD 102. A signal processing circuit 103 for D conversion output, a camera signal processing circuit 104 for converting a digitally converted imaging signal into a video signal, a microcomputer 106 for detecting movement of an image from the imaging signal and controlling each part, and driving of the CCD 102 A timing generator (TG) 105 for performing

  Imaging light corresponding to a subject entering through the imaging lens 101 is supplied to the CCD 102 and converted into an electrical signal. Drive control of image capture and readout at that time is performed by a TG 105 described later. The video signal converted into an electrical signal by the CCD 102 is supplied to the signal processing circuit 103.

  The signal processing circuit 103 arranges and outputs the supplied video signal to a video signal for display or recording. At the same time, the motion of the image is detected by known motion detection means. The motion information detected by the motion detection means is supplied to the microcomputer 106.

  The microcomputer 106 determines the degree of motion according to the motion information of the supplied image. The microcomputer 106 prepares a plurality of driving clocks to be supplied to the CCD 102, the signal processing circuit 103, and the camera signal processing circuit 104, and selects a driving frequency according to the determined degree of movement.

  That is, when the motion of the currently captured image is large depending on the determined degree of motion, the CCD 12, the signal processing circuit 103, and the camera signal processing circuit 104 are driven at a normal driving frequency. When the motion of the image is small, the CCD 102, the signal processing circuit 103, and the camera signal processing circuit 104 select and drive a frequency lower than the normal driving frequency.

  The TG 105 controls the drive and readout of the CCD 102 based on the drive frequency supplied from the microcomputer 106.

  As a result, when the movement of the image is small, the power consumption of the CCD 102 can be suppressed. In the signal processing circuit 103 and the camera signal processing circuit 104, the power consumption of the entire imaging apparatus can be suppressed by driving at a frequency corresponding to the driving frequency of the CCD 102.

  In the above description, an example is shown in which the drive clocks supplied to the CCD 102, the signal processing circuit 103, and the camera signal processing circuit 104 are all selected and controlled. However, in the case where a CCD whose drive frequency cannot be changed is used. Alternatively, the driving frequency supplied to the CCD may be unchanged, and the driving clock supplied to the signal processing circuit 103 and the camera signal processing circuit 104 may be selected according to the movement of the image.

  That is, when the motion of the currently captured image is large depending on the determined degree of motion, the signal processing circuit 103 and the camera signal processing circuit 104 are driven at a normal driving frequency. When the motion of the image is small, the signal processing circuit 103 and the camera signal processing circuit 104 select and drive a frequency lower than the normal driving frequency.

  As a result, when the motion of the image is small, the signal processing circuit 103 and the camera signal processing circuit 104 can be driven at a frequency lower than the drive frequency of the CCD, thereby suppressing the power consumption of the entire imaging apparatus. .

It is a schematic block diagram of the imaging device applied to a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Imaging device 101 ... Imaging lens 102 ... Solid-state image sensor (CCD)
103 ... Signal processing circuit 104 ... Camera signal processing circuit 105 ... Timing generator (TG)
106: Microcomputer

Claims (1)

An imaging device using a solid-state imaging device that photoelectrically converts a subject image formed by a photographing lens,
A timing generator for controlling the readout timing of the solid-state imaging device;
A signal processing circuit for converting a video image photoelectrically converted by the solid-state imaging device into a digital video signal;
A camera signal processing circuit for generating an imaging output video signal, comprising motion detection means for detecting motion information that is a degree of motion based on the digital video signal;
A microcomputer for determining the degree of movement of the imaging output video signal from the movement information;
The imaging apparatus is characterized in that the microcomputer supplies a drive clock having a frequency corresponding to the determined degree of movement to the timing generator, the signal processing circuit, and the camera signal processing circuit.

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