KR20110115315A - Photographing apparatus having image sensor - Google Patents

Abstract

The present invention relates to a photographing apparatus including an image sensor, and discloses a technology of controlling an output of an analog image without a PIR sensor by embedding a motion detection function in the image sensor. The present invention includes a sensor unit for photographing an image of a subject through an image sensor and outputting an image signal, and a storage device storing an image output signal applied from the sensor unit, wherein the sensor unit detects motion from the image signal. And a sensor driver for selectively outputting an image output signal to the storage device according to whether the motion is detected. Accordingly, the present invention can simplify the system and reduce the cost of the system.

Description

Shooting apparatus including an image sensor {PHOTOGRAPHING APPARATUS HAVING IMAGE SENSOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing apparatus including an image sensor, and more particularly to an image sensor for converting an external optical image signal into an electrical image signal.

In general, an image sensor is a device that converts an external optical image signal into an electrical image signal. In particular, CMOS image sensors are image sensors fabricated using CMOS fabrication techniques. In the CMOS image sensor, each pixel stores the light signal radiated from the corresponding part of the object after converting it into electrons using a photodiode, and converts the amount of charge appearing in proportion to the accumulated number of electrons into a voltage signal and outputs the voltage signal. Use

Image sensors are largely divided into CMOS image sensors using complementary-MOS (CMOS) technology and CCD image sensors using Charge Coupled Device (CCD) technology, all of which are manufactured using semiconductor technology.

Such a CMOS image sensor is a device widely used in various electronic products, for example, a mobile phone, a camera for a personal computer (PC), a video camera, a digital camera, and the like.

The CMOS image sensor is simpler to drive than the CCD used as an image sensor, and it is possible to integrate a signal processing circuit into one chip so that a system on chip (SoC) can be used to make the module smaller. Let's do it. In addition, since the conventional set-up (CMOS) technology can be used interchangeably, there are many advantages such as lowering the manufacturing cost, so the demand is increasing rapidly.

In general, a photographing apparatus including an image sensor such as a digital camera, a camcorder, and a portable terminal in which a camera function is implemented, acquires an image signal by capturing an image input through a lens with an image sensor. The video signal is converted into digital video data and displayed on a liquid crystal screen as a preview screen. When the user presses the shutter key while the preview image is displayed, the image data is compressed and stored as photo data.

1 is a block diagram of a photographing apparatus including a conventional image sensor.

The conventional photographing apparatus includes a sensor unit 10 and a video recorder 20. Here, the sensor unit 10 includes an image sensor 11, a light emitting element 12, an image sensor driver 13, a pyroelectric infrared sensor 14, hereinafter referred to as a 'PIR sensor', and a PIR sensor. The drive unit 15 is included. The video recorder 20 is formed of a digital video recorder including a hard disk 21.

The image sensor 11 photographs a subject under the control of the image sensor driver 13 and outputs an analog or digital video image output signal to the video recorder 20.

In addition, the light emitting element 12 may be formed of a light emitting diode (LED) or an infrared (IR) light emitting diode (LED) to output an infrared light source to the outside.

The image sensor driver 13 controls the driving of the image sensor 11, converts an image acquired through the image sensor 11, and outputs an image output signal to the video recorder 20.

The PIR sensor 14 detects the presence or absence of a person under the control of the PIR sensor driver 15 and outputs a PIR sensor detection signal to the video recorder 20.

The PIR sensor driver 15 controls the driving of the PIR sensor 14, converts an image acquired through the PIR sensor 14, and outputs a PIR sensor detection signal to the video recorder 20.

The video recorder 20 includes a hard disk 21 therein to store an image output signal applied from the sensor unit 10 and a PIR sensor detection signal.

Recently, many convergence products combining the PIR sensor 14 and the image sensor 11 have been released. The conventional photographing apparatus detects the presence or absence of a person through the sensing of the PIR sensor 14.

For example, when the PIR sensor 14 is applied to a security system, when the presence or absence of a person or an animal is detected by the PIR sensor 14, the image sensor 11 stores an image on the hard disk 21, and the person Alternatively, when the presence of the animal is confirmed, a warning sound is generated outside.

The conventional imaging apparatus further includes a separate PIR sensor 14 in addition to the image sensor 11 to detect the presence or absence of a human or animal. Accordingly, a line for detecting an image output signal and a line for detecting a PIR sensor detection signal, that is, two lines, must be provided between the sensor unit 10 and the video recorder 20.

Accordingly, not only the cost of implementing the photographing system including the image sensor increases, but there is a problem in that the photographing system cannot be easily implemented due to various line increases.

On the other hand, the hot wire sensor device is a device for detecting the presence or absence of the human body in the monitoring area by detecting a change in its value using infrared light.

The hot wire sensor device is divided into two types, active and passive, according to its operation principle. The active heating sensor device installs the receiver and the transmitter in a fixed place at a certain place and in a certain direction, and receives the infrared light from the transmitter. Device.

In addition, the passive heating sensor device is a device that installs only a pyroelectric infrared sensor having a wide viewing angle, and when the human body approaches the viewing angle, the sensor detects a corresponding infrared ray and generates an alarm.

The PIR sensor 14 used as a motion detection sensor uses a passive infrared detection method and uses a detection sensor called an infrared sensor.

Such infrared sensors are very sensitive to changes in ambient temperature, which can cause many malfunctions. In addition, it cannot be used by being installed next to a lighting device such as an incandescent lamp or a fluorescent lamp that generates high heat formed inside the lighting case.

The present invention has been made to solve the above-mentioned conventional problems and has the following object.

First, without a separate PIR sensor, by detecting the motion (Motion) through the image sensor it is possible to detect the presence or absence of human (or animal) movement with only the image sensor.

Second, an image sensor detects whether a person, an animal, or an object moves, and determines whether an image signal is output based on whether motion is detected.

Third, when the image output signal is applied from the image sensor, the image signal is stored in the storage device. When the image output signal is not applied, the image signal is switched to the power save mode to reduce the current consumed.

Fourth, since the motion detection function is performed in the image sensor without including a separate PIR sensor, the system can be simplified and the cost of the system can be reduced.

Fifth, in low light, it is possible to solve the weakness in low light by judging the light using a light sensor and detecting the motion by outputting an infrared light source.

The imaging apparatus including the image sensor of the present invention for achieving the above object, the sensor unit for photographing the image of the subject through the image sensor to output an image signal; And a storage device to store an image output signal applied from the sensor unit, wherein the sensor unit includes a sensor driver to detect a motion from the image signal and selectively output the image output signal to the storage device according to whether the motion is detected. It is characterized by.

The present invention provides the following effects.

First, without a separate PIR sensor, by detecting the motion (Motion) through the image sensor it is possible to detect the presence or absence of human (or animal) movement with only the image sensor.

Second, by detecting the movement of a person, animal or object through the image sensor, and determines whether to output the video signal according to the motion detection, the storage space of the storage device can be used freely, the input / output of the video signal It is possible to reduce the current consumption due to driving and storage.

Third, when the image output signal is applied from the image sensor, the image signal is stored in the storage device. When the image output signal is not applied, the image signal is switched to the power save mode to reduce the current consumed.

Fourth, it is possible to solve the load problem of the image storage device by storing the image signal in the storage device only when the image output signal is applied from the image sensor.

Fifth, since the motion detection function is performed in the image sensor without including a separate PIR sensor, the system can be simplified and the cost of the system can be reduced.

Sixth, since there is no separate PIR sensor, it is possible to reduce the wiring associated with the PIR sensor to facilitate the installation of the imaging system product.

Seventhly, in low light, it is possible to solve the weakness in low light by judging the light using a light sensor and outputting an infrared light source to detect motion.

It will be apparent to those skilled in the art that various modifications, additions, and substitutions are possible, and that various modifications, additions and substitutions are possible, within the spirit and scope of the appended claims. As shown in Fig.

1 is a block diagram of a photographing apparatus including a conventional image sensor.
2 is a block diagram of a photographing apparatus including an image sensor according to the present invention;
3 is a detailed configuration diagram illustrating a sensor driver of FIG. 2.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a photographing apparatus including an image sensor according to the present invention.

The present invention includes a sensor unit 100 and a storage device 200. The sensor unit 100 includes an illuminance sensor 110, an image sensor 120, a light emitting device 130, and a sensor driver 140. In addition, the storage device 200 includes a synchronization detector 210 and a storage 220. Here, the storage device 200 preferably comprises a digital video recorder or the like for storing digital images. The storage unit 220 preferably includes a storage medium such as a hard disk.

First, the illumination sensor 110 detects ambient brightness information, and the brightness information detected by the illumination sensor 110 is output to the sensor driver 140.

The sensor driver 140 controls the brightness information applied from the illuminance sensor 110 to control the turn on or turn off operation of the light emitting device 130.

Recently, in the terminal market, LEDs or IR LEDs are used as essential elements to improve low light sensitivity of cameras used in surveillance or door locks. That is, the illumination sensor 110 is used to control the light emitting device 130 according to the illumination of the surrounding environment.

The sensor driver 140 includes an analog-to-digital converter to receive the sensing result of the illuminance sensor 110 and perform signal processing.

The image sensor 120 captures a subject under the control of the sensor driver 140 and outputs an analog or digital video image output signal to the storage device 200.

That is, the image sensor 120 converts an optical image (ie, an optical object signal) input through an external lens into an electrical signal and outputs the electrical signal. In this case, an electrical signal output every frame is referred to as a frame image.

The image sensor 120 outputs a frame image having a constant frame rate or a varying frame rate. Here, the image sensor 120 may be a Charge Coupled Device (CCD) type or a Complementary Metal-Oxide-Silicon (CMOS) type.

The light emitting device 130 includes a light emitting diode (LED) or an infrared light emitting diode (IR) to output an infrared light source to the outside.

The sensor driver 140 controls the driving of the image sensor 120, converts an image obtained through the image sensor 120, and outputs an image output signal to the storage device 200.

In the present invention, the image sensor 120 detects the movement of a person, an animal or an object under the control of the sensor driver 140, and outputs an image output signal to the storage device 200.

For example, when the image sensor 120 is applied to a security system, when the presence or absence of a person or an animal is detected in the image sensor 120, the image sensor 120 stores the image in the storage device 200 and the person. Alternatively, when the presence of the animal is confirmed, a warning sound is generated externally.

The synchronization detector 210 detects a synchronization signal from an analog image signal applied from the sensor driver 140. The analog video signal includes a synchronization signal every frame. When such a synchronization signal is detected, it indicates that a video signal is being input.

Therefore, when the synchronization signal is detected in the image signal applied from the sensor driver 140, the synchronization detector 210 recognizes that the motion is detected and stores the image signal in the storage 220.

The storage unit 220 may be implemented as a hard disk or the like, and stores the image signal applied through the synchronization detector 210.

3 is a detailed configuration diagram illustrating the sensor driver 140 of FIG. 2.

The sensor driver 140 includes an analog to digital converter 141, a controller 142, a motion detector 143, a digital analog converter (DAC) 144, and a light emission controller 145.

Here, the analog-to-digital converter (ADC) 141 provided in the sensor driver 140 converts an analog signal for brightness information applied from the illumination sensor 110 into a digital signal and controls the controller 142. Output to

The controller 142 controls an image signal of a subject photographed from the lens of the image sensor 120 according to a digital signal or an internal control signal applied from the analog to digital converter 141 and outputs the image signal to the motion detector 143. The controller 142 outputs the digital signal applied from the analog-digital converter 141 to the light emission controller 145.

The light emission controller 145 controls the brightness information applied from the illumination sensor 110 through the analog-to-digital converter 141 and the control unit 142 to determine the light emitting device of the light emitting unit 130 according to the illumination level. Selectively control the turn on or turn off operation.

The light emitting unit 130 may include a light emitting device such as a light emitting diode (LED) or an infrared light emitting diode (IR).

The controller 142 stores operation information for controlling the turn on or turn off operation of the light emitter 130.

Accordingly, the controller 142 outputs an operation control signal for controlling the operation of the light emitter 130 to the light emission controller 145 according to the operation information read from the internal register.

In addition, the present invention may include a motion detection unit 143 in the sensor driver 140 of the sensor unit 100 without detecting a PIR sensor. In addition, the image sensor 120 allows the PIR sensor to detect whether or not the object moves.

That is, the motion detector 143 detects the occurrence of motion in the video signal applied from the controller 142 and outputs the motion detection signal MD to the digital-to-analog converter 144.

The motion detector 143 activates the motion detection signal MD (eg, to a logic high level) when the motion is detected from the video signal applied from the controller 142, and outputs the motion detection signal MD. On the other hand, when the motion is not detected in the video signal applied from the controller 142, the motion detector 143 deactivates the motion detection signal MD (eg, to a logic low level) and outputs the motion.

The present invention determines whether to output the digital analog converter 144 according to whether the motion detection signal MD output from the motion detector 143 is activated.

That is, the digital analog converter 144 converts the digital video signal applied from the controller 142 into an analog signal under the control of the motion detection signal MD and selectively outputs the video output signal to the storage device 200.

In this case, the digital-to-analog converter 144 outputs an image output signal to the storage device 200 only when the motion detection signal MD is activated and applied from the motion detector 143. On the other hand, the digital-to-analog converter 144 does not output the image output signal to the storage device 200 when the motion detection signal MD is deactivated and applied from the motion detector 143.

The synchronization detector 210 of the storage device 200 detects a synchronization signal from an analog image signal applied from the digital-to-analog converter 144.

That is, when the analog video signal is applied from the digital analog converter 144, the motion detection unit 143 indicates the motion detected. Therefore, the sync detector 210 detects the sync signal and stores the analog video signal in the storage 220.

On the other hand, when no analog video signal is applied from the digital-to-analog converter 144, the motion detector 143 represents a situation where no motion is detected, and thus the storage device 200 operates in a power save mode. In the power save mode, since the sync signal is not detected by the sync detector 210, the analog video signal is not stored in the storage 220.

Subsequently, when the image signal is applied from the digital-to-analog converter 144 to the synchronization detector 210 again, the storage device 200 ends the power save mode and stores the image signal in the storage unit 220.

On the other hand, the motion detection unit 143 described above may be a variety of ways to detect the motion.

For example, the process of receiving a frame image from the control unit, generating a difference image between the frame image of the current frame and the previous frame received, the process of obtaining the projection data by projecting the difference image on the reference axis, Extracting feature information from the projection data, analyzing the trajectory of the feature information, and obtaining the motion information of the subject using the analyzed trajectory.

Looking at the operation process in detail as follows.

First, a sequential (or non-sequential) frame image is received from the image sensor 120 through the controller 142. The input frame image may be a color image or a black and white image. For color images, you can either use the color image as it is or convert it to a black and white image. In the case of a black and white image, the overall amount of calculation of the motion detector 143 may be reduced in detecting the motion of the subject.

The frame image input to the motion detector 143 is stored in the image storage unit. Assuming that the currently received frame is the n-th frame, the image storage unit stores a frame image corresponding to the previous frame (n-1 th frame).

A difference image is generated using the current frame image (n-th frame image) input to the motion detector 143 and the previous frame image (n-1 th frame image) read from the image storage unit. For any pixel location, set the difference in pixel values in the two frame images to the pixel values in the difference image.

When generating the difference image, operations such as cropping or masking of the frame image may be additionally performed according to the motion detection width. Here, the motion detection width means a motion direction, a motion size, etc. of a subject that can be detected by the motion detection unit 143 according to the present invention.

The motion detector 143 projects the difference image described above onto a reference axis. Projection data about the reference axis is obtained by projecting the difference image onto the reference axis.

The projected data is grouped according to a preset method, and feature information is generated through the difference of each divided group. The generated feature information is stored in the feature information storage unit and used to acquire motion information such as a trajectory.

That is, the presence or absence of motion of the subject is determined by determining whether the trajectory of the feature information over time has a preset form (for example, a sine waveform) based on the feature information. In the case of having a preset form, it is determined that there is motion in a specific direction with respect to the detection reference point when the magnitude is greater than or equal to a predetermined threshold.

In addition, the motion detector 143 may detect motion in the following manner.

The pixel array of the image sensor 120 including the pixels in a matrix form detects light from a subject and outputs the light as an electric signal. The motion detector 143 selects the electric signals of the pixel array in units of columns.

The electrical signal selected in units of columns is compared with a reference voltage and output as digital data of 1 bit. Thereafter, one bit of digital data is temporarily stored, and the current frame is compared with the previously stored previous frame. As a result of the comparison, the number of " 1 " or " 0 "

In addition, the motion detector 143 may detect motion in the following manner.

First, the input video image is converted into digital image data through the analog-to-digital converter 141 and output as current frame data. The motion detector 143 converts the row pixel values in units of columns and stores them as reference frame data. The correlation coefficient is calculated by comparing the current frame data of the image with the stored reference frame data and stored therein.

Thereafter, the maximum value of the correlation coefficient is retrieved and the corresponding local motion vector is output. Then, the motion vector of the entire image is obtained using the local motion vector.

Since the present invention stores the image signal in the storage unit 220 only when the image signal is detected, the load can be prevented from being stored in the storage unit 220, and the storage space of the storage unit 220 can be freely spaced. And may contribute to extending the product life of the storage device 200. In addition, it is possible to reduce the current consumption due to the input / output, driving and storage of the image signal.

In addition, the present invention detects the illuminance through the illuminance sensor 110, and turns on the light emitting device through the light emitting unit 130 in a dark environment of low illuminance. Accordingly, the image sensor 120 receives an image related to motion so that the motion detection unit 143 does not have difficulty in detecting the motion.

This embodiment of the present invention is attached to a closed circuit television (CCTV), a digital video recorder (DVR), a door camera, a digital camera, a camcorder, or a portable communication device. It can be applied to an imaging device such as a camera.

Claims (13)

A sensor unit for photographing an image of a subject through an image sensor and outputting an image signal; And
A storage device storing an image output signal applied from the sensor unit,
And the sensor unit includes a sensor driver that detects a motion from the image signal and selectively outputs the image output signal to the storage device according to whether the motion is detected. The method of claim 1, wherein the sensor driver
A controller which receives the video signal and processes the signal;
A motion detector for detecting a motion from the output image of the controller and outputting a motion detection signal; And
And converting the output image of the controller into an analog signal and selectively outputting the image output signal converted into the analog signal to the storage device according to whether the motion detection signal is activated. Imaging device comprising an image sensor. The photographing apparatus of claim 2, wherein the motion detector detects whether a person moves. The photographing apparatus of claim 2, wherein the motion detector detects whether an animal moves. The photographing apparatus of claim 2, wherein the motion detector detects whether an object moves. The image sensor of claim 1, wherein the storage device detects a synchronization signal from the image output signal applied from the sensor unit, and stores the image signal only when the synchronization signal is detected. Shooting device. 7. The photographing apparatus of claim 6, wherein the storage device operates in a power save mode when the synchronization signal is not detected. The apparatus of claim 1 or 6, wherein the storage device is
A synchronization detector for detecting a synchronization signal from the image output signal applied from the sensor unit; And
And a storage unit which stores the image output signal when the synchronization signal is detected. 7. An imaging device according to claim 1 or 6, wherein the storage device comprises a digital video recorder. The method of claim 1, wherein the sensor unit
An illumination sensor for sensing brightness information;
And an image sensor which is operated under the control of the sensor driver and further comprises a light emitting part which operates in correspondence with the level of the brightness information. The method of claim 10, wherein the sensor driver
An analog-digital converter for signal processing the brightness information applied from the illuminance sensor;
A controller for receiving a digital signal from the analog-to-digital converter and processing the signal; And
And an image sensor for controlling the operation of the light emitting unit according to the output of the controller. The photographing apparatus of claim 10, wherein the light emitting unit comprises an infrared light emitting diode. The photographing apparatus of claim 10, wherein the light emitting unit comprises a light emitting diode.

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