KR0141733B1 - Method & apparatus for controlling light quantity for a camcorder - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for adjusting the amount of light in a camcorder. In the related art, since the closing amount of the aperture controlling the amount of light in a very bright situation is large, the amount of light reaching the image pickup device is reduced, and the sensitivity of the image pickup device is lowered. There was a problem that the state was not clear. In order to improve this point, the present invention increases the shutter speed until a smear noise occurs and then adjusts the open state of the aperture to adjust the amount of light or the shutter until after the smear noise occurs. The present invention is designed to improve the sharpness of the screen by increasing the speed. The present invention does not adjust the amount of opening of the aperture unconditionally when the amount of light is adjusted, but when the magnitude of the luminance signal is large enough to control it. The sharpness of the screen can be improved by increasing the shutter speed before generating smear noise and then adjusting the amount of light with the aperture.

Description

Method and device for adjusting the amount of light in a camcorder

1 is a block diagram of a conventional light quantity control device.

2 is a block diagram of the light amount control device of the present invention.

3 is a detailed block diagram of a smear detection unit in FIG. 2;

4 is an exemplary view of a screen according to smear detection in FIG.

5 and 6 are signal flow charts for adjusting the amount of light of the present invention.

* Explanation of symbols for the main parts of the drawings

201: Aperture (IRIS) 202: Imaging element (CCD)

203: Sampling unit 204: Luminance detection unit

205: Automatic gain control unit (AGC) 206: Smear detection unit

207: microcomputer 208: timing control unit

209: Aperture drive unit 211: Band pass filter (BPF)

212: region divider 213: integral adder

214: Comparators

The present invention relates to adjusting the amount of incident light of a camcorder. In particular, a method and apparatus for adjusting the amount of light of a camcorder to obtain a clear screen by adjusting a shutter speed until a smear noise is detected when a level of an incident luminance signal is higher than a predetermined value. It is about.

FIG. 1 is a block diagram of a conventional light amount adjusting device, as shown therein, an aperture 101 for adjusting an amount of incident light, and an imaging device 102 for detecting light passing through the aperture 101 and converting the light into an electrical signal. ), A sampling unit 103 for sampling the output of the imaging device 102 to extract a video signal, a luminance detection unit 104 for detecting a luminance component from the video signal of the sampling unit 103, and this luminance. The diaphragm driver 105 adjusts the diaphragm 101 according to the size of the luminance component extracted by the detector 104.

The output signal of the sampling unit 103 is input to the signal processing circuit after the gain is adjusted in the automatic gain control unit 106 and is separated into luminance and color signals.

Referring to the operation of the conventional device as follows.

First, when the light incident on the optical system is focused through the lens and then adjusts the amount of light in the aperture 101, the imaging device 102 detects the amount of incident light and converts it into an electrical signal.

At this time, the sampling unit 103 samples the electrical signal of the image pickup device 102 to extract the video signal, and the luminance detector 104 detects the luminance component from the video signal.

Therefore, the aperture driver 105 adjusts the open state of the aperture 101 according to the magnitude of the luminance component detected by the luminance detector 104 to adjust the amount of incident light.

Accordingly, since the magnitude of the luminance component of the video signal extracted after sequentially passing through the image pickup device 102 and the sampling unit 103 is adjusted, the gain after the video signal is adjusted by the automatic gain control unit 106 is adjusted. When an image is displayed on the screen through the processing circuit, the screen becomes clear.

However, in the related art, the amount of light is controlled by using an aperture, but in a very bright situation, the closing amount of the aperture is large, so that the amount of light reaching the image pickup device is reduced.

Therefore, conventionally, there is a problem that the screen state is not clear because the sensitivity of the imaging device is lowered due to the reduction of the amount of light.

The present invention increases the shutter speed until the noise is generated after adjusting the open state of the aperture and then adjusting the open state of the aperture after the shutter speed is increased until the noise occurs to improve the conventional problem. It is an object of the present invention to provide a method and apparatus for adjusting the amount of light of a camcorder created to improve the sharpness of a screen.

In order to achieve the above object, the present invention provides a method for determining whether a luminance component level of incident light is equal to or higher than a fixed level. Detecting a luminance component to determine whether smear noise is detected; if no smear noise is detected in the step, increasing the shutter speed by one step until smear noise is detected; and in the step, smear noise When the detection is detected, the shutter speed is decreased by one step, and then the aperture is adjusted.

In another aspect, the present invention is to determine whether the level of the incident luminance component is above a certain value by adjusting the opening state of the aperture after fixing the shutter speed to the normal state to achieve the above object, and the incident luminance in the step Determining whether smear noise is detected while increasing the shutter speed by one step if the level of the component is higher than a predetermined value; and decreasing the shutter speed by one step when smear noise is detected in the step. do.

The present invention provides an aperture for controlling the amount of incident light for performing the above steps, an imaging device for converting the light amount of the aperture into an electrical signal, a sampling means for extracting a video signal from the output signal of the imaging device, and the sampling means. Luminance detection means for detecting the luminance component from the video signal of the signal, automatic gain adjusting means for adjusting the gain of the video signal of the sampling means, and output signal of the automatic gain adjusting means by band filtering to extract the luminance component and then divide the equally Smear detection means for detecting smear noise by integrating and accumulating the divided signals, and adjusting the opening amount of the aperture through an aperture driving means according to the magnitude of the luminance component of the brightness detection means and detecting the smear. The output of the means is compared with the previous output value to determine whether smear noise is generated. And a control means for adjusting the shutter speed of the image pickup device via an iming generating means.

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

2 is a block diagram of the present invention, as shown therein, an aperture 201 for adjusting the amount of incident light, an image pickup device for detecting an amount of light adjusted by the aperture 201, and converting it into an electrical signal; A sampling unit 203 for sampling the output signal of the imaging device 202 to extract a video signal, a luminance detector 204 for extracting luminance components from the video signal of the sampling unit 203, and the sampling unit An automatic gain adjusting unit 205 for adjusting the gain of the video signal of 203, a smear detecting unit 206 for determining whether smear noise is generated by arithmetic processing of the video signal of the automatic gain adjusting unit 205, The aperture driving signal is output according to the magnitude of the luminance component of the luminance detector 204 and the timing control signal is output by comparing the output of the smear detector 206 with a previous output value to determine whether smear noise has occurred. The chronocomputer 207, the aperture driver 209 for adjusting the opening amount of the iris 201 according to the iris drive signal of the microcomputer 207, and the timing control signal of the microcomputer 207 It is comprised by the timing control part 208 which adjusts a shutter speed by adjusting the sensitivity of the imaging element 202. FIG.

As shown in FIG. 3, the smear detection unit 206 band-filters the video signal of the sampling unit 203 to extract the luminance component, and the luminance component of the band pass filter 211 is divided into regions. Comparing the area divider 212, the integral adder 213 that accumulates each output signal of the area divider 212 and accumulating for one field, and the output value of the integral adder 213, the highest value is extracted and The comparator 214 outputs the upper and lower values of the highest value to the microcomputer 207.

Referring to the operation and effect of the present invention configured as described above are as follows.

When the light incident on the optical system is focused on the lens and then incident on the imaging device 202 through the aperture 201 and converted into an electrical signal proportional to the amount of light, the sampling unit 203 adjusts the gain of the electrical signal and then samples the light. Through extracting the video signal through the automatic gain control unit 205 adjusts the gain by inputting the video signal of the sampling unit 203.

First, in an embodiment of the present invention, when the luminance detector 204 detects a luminance signal from the beading signal extracted by the sampling unit 203, the microcomputer 207 determines whether the level of the luminance signal is greater than or equal to a predetermined value. .

At this time, if the level of the incident luminance signal is higher than or equal to a predetermined value, the microcomputer 207 outputs a drive signal to the aperture driver 209 to adjust the aperture 201 to the maximum open state and at the same time the shutter speed ( The control signal is output to the timing controller 208 to adjust S / S to the normal speed (1/60 second).

Accordingly, the aperture driver 209 adjusts the aperture 201 to the maximum open state, and the timing controller 208 controls the timing of outputting the accumulated charge of the imaging device 202 at the normal shutter speed (1/60 second). .

Thereafter, the light incident on the optical cradle is converted into an electrical signal by the image pickup device 202 through the aperture 201 and the video signal is extracted by the sampling unit 203, and then the gain is obtained by the automatic gain control unit 2-05. When this adjustment is made, the smear detector 206 extracts a luminance component from the video signal to detect the occurrence of smear noise.

That is, the smear detection unit 206 extracts the luminance signal from the video signal of the automatic gain control unit 205 by the band pass filter (BPF) 211 through the band filtering. When the integral adder 213 integrates 16 video signals divided by the area divider 212 and accumulates them for one field, the comparator 214 compares each signal to determine the signal having the maximum value. Done.

The comparator 214 infers the corresponding region of the maximum value and outputs the values of the upper and lower regions of the region to the microcomputer 207.

Here, the reason why the comparator 214 outputs values of the upper and lower regions of the region corresponding to the maximum value is that smear noise occurs as vertical lines on the screen when light from an extremely bright light source such as a sun is incident. This is because the faster the shutter speed (S / S), the more likely to occur.

When the comparator 214 determines the region corresponding to the maximum value, the comparator 214 outputs a signal corresponding to the upper and lower regions of the region in the case of FIG. 4 (a). A signal corresponding to the upper region of the region is output, and in the case of FIG. 4C, a signal corresponding to the lower region of the region is output.

At this time, the microcomputer 207 compares the output signal of the smear detection unit 206 with the previous output value to determine whether a level difference is detected.

Accordingly, if there is no level difference and smear noise is not detected, the microcomputer 2-7 controls the timing controller 208 to adjust the sensitivity of the imaging device 202 so that the shutter speed S / S is adjusted by one step. The operation of increasing and determining whether smear noise has occurred is repeated.

The shutter speeds S / S are 1/60, 1/120, 1/250, 1/500, 1/1000, 1/2000, 1/4000, 1/10000.

In addition, when smear noise occurs, the microcomputer 207 controls the timing controller 208 to reduce the shutter speed S / S by one step to adjust the luminance level to an appropriate level, and then the aperture driver 209. ), The amount of incident light is adjusted by adjusting the opening amount of the diaphragm 201.

That is, the operation initially adjusts the aperture 201 to the full open state, and then increases the shutter speed S / S until smear noise occurs according to the luminance signal magnitude of the incident light. Then, the amount of incident light is adjusted by adjusting the opening amount of the diaphragm 201.

Meanwhile, in another embodiment of the present invention, when the light amount adjustment operation is started, the microcomputer 207 fixes the sensitivity of the imaging device 202 at the normal shutter speed (S / S = 60 seconds) through the timing controller 208. Afterwards, the output signal level of the luminance detector 204 is detected by adjusting the opening state of the aperture 201 through the aperture driver 209 to determine whether or not the predetermined value is greater than or equal to the predetermined value.

At this time, when the output level of the luminance detector 204 is higher than or equal to a predetermined value, the microcomputer 207 determines that the high luminance signal is in a control state and sets the shutter speed S / S by one step through the timing controller 209. While increasing, the output value of the smear detection unit 206 is compared with the previous output value to determine whether there is a level difference.

Accordingly, if the output value of the smear detection unit 206 does not have a level difference with the previous output value and there is no smear noise, the shutter speed S / S is increased by one step, and then the output value of the smear detection unit 206 is detected again to obtain smear noise. Is detected.

When smear noise occurs, the microcomputer 207 controls the timing controller 209 to decrease the shutter speed S / S by one step and then terminates the light amount adjusting operation.

As described in detail above, the present invention does not adjust the amount of opening of the aperture unconditionally when the amount of light is adjusted, but does not adjust the amount of light, but when the magnitude of the luminance signal is large enough to control the shutter speed until a smear noise occurs. By increasing the brightness of the screen by adjusting the amount of light with the aperture has the effect of improving the sharpness.

Claims (6)

In the first step of determining whether the smear noise is detected after initially fixing the opening state of the iris to the maximum and adjusting the shutter speed S / S to the normal state, and if the smear noise is not detected in the first step, A second step of determining whether smear noise is detected while increasing the shutter speed by one step; a second step of determining whether smear noise is detected in the first and second steps; and smear noise in the second and second steps. And detecting the opening speed of the aperture by reducing the shutter speed by one step if detected. The method of claim 1, further comprising: performing an initial operation when the luminance component level of the incident light is equal to or greater than a predetermined value. A first step of adjusting the opening state of the aperture after fixing the shutter speed (S / S) to the normal state, and a smear noise while increasing the shutter speed by one step after adjusting the opening state of the aperture in the first step. And a third step of determining whether or not the detection is detected, and a third step of reducing the shutter speed by one step when smear noise is detected in the second step. The method of claim 3, further comprising: determining whether smear noise is detected while increasing the shutter speed S / S by one step when the level of the incident luminance component is higher than a predetermined value when the opening state of the aperture is adjusted. How to adjust the amount of light in your camcorder. An aperture for adjusting the amount of incident light by the aperture driving means, an imaging element for outputting an electrical signal proportional to the amount of light adjusted for the aperture, a sampling means for converting the output signal of the imaging element into a video signal, and the sampling means Luminance detection means for detecting a luminance component in the video signal of the signal, automatic gain adjusting means for adjusting the gain of the video signal of the sampling means, and an output signal of the automatic gain adjusting means by band-filtering to extract the luminance component and then divide it equally Smear detection means for detecting smear noise by integrating, accumulating, and comparing the divided signals with each other; and adjusting the opening amount of the aperture through the aperture driving means according to the magnitude of the luminance component of the brightness detection means, The output of the detection means is compared with the previous output value to determine whether smear noise And control means for outputting a signal for controlling the shutter speed of the imaging element, and timing control means for adjusting the shutter speed of the imaging element by the control of the control means. 6. The smear detection means according to claim 5, wherein the smear detection means includes a band pass filter 211 for band-filtering the video signal of the sampling means to extract the luminance component, and an area divider 212 for region-dividing the luminance component of the band pass filter 211. Control means for integrating each output signal of < RTI ID = 0.0 > integral < / RTI > And a comparator (214) for outputting to the camcorder.