KR100844848B1 - Apparatus and method for cancelling color rolling in camera - Google Patents

Abstract

An apparatus and a method for removing the color rolling of a camera are provided to receive and detect the frequency of light directly by using a PT(Photo Transistor) and synchronize the frequency of light with the internal clock frequency of a camera, thereby removing the color rolling efficiently when an AC(Alternating Current) voltage is not used. A PT(41) receives light used in camera photographing. The PT receives light of 120Hz fluorescent lighting and converts it into an electric signal. A frequency detector(40) detects a lighting frequency corresponding to the received light. A PLL(Phase Locked Loop) unit(39) synchronizes the detected lighting frequency and the clock frequency of a camera. A PLL on/off switch(42) drives a CCD(Charge-Coupled Device) vertical drive signal to the synchronized frequency for removing the color rolling of the camera.

Description

Apparatus and method for canceling color rolling in camera}

Figure 1 shows the configuration for the color rolling removal device of a typical camera,

2 illustrates an embodiment of a color rolling generation process of a general camera,

Figure 3 shows the configuration of the color rolling removal device of the camera according to the present invention,

Figure 4 shows a detailed configuration of the color rolling removal device of the camera according to the present invention,

5 illustrates an embodiment of a color rolling removal process of a camera according to the present invention.

※ Explanation of code for main part of drawing

10,30: Lens 11,31: Iris

12,32: CD 13,33: automatic gain adjuster

14,34: digital signal processing unit 15,35: CD drive unit

16,36: microcomputer 17,37: clock oscillator

18,38: Memory 19,39: PIEL

20,40: frequency detector 21: AC power input

41: phototransistor 42: PEL on / off switching unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for removing color rolling of a camera. For example, due to a difference between a frequency of luminescent lighting such as a fluorescent lamp and an internal clock frequency of the camera, color components of the photographed image are distorted. The present invention relates to a color rolling removal apparatus and a method of a camera for removing color rolling.

1 illustrates a configuration of a color rolling removal device of a general camera. For example, various types of cameras, such as a surveillance camera, include a lens 10, an IRIS 11, and a CDC. 12, automatic gain adjuster 13, digital signal processor 14, CD driver 15, microcomputer 16, clock oscillator 17, memory 18, PLEL 19, frequency detector 20, and the AC power input unit 21 is configured to be included.

Meanwhile, the microcomputer 16 performs a camera photographing operation according to a user's request. The light incident on the CD 12 through the lens 10 and the iris 11 is an electric signal. After photoelectric conversion, it is input to the digital signal processor 14 via the automatic gain adjuster 13.

In addition, the frequency detector 20 detects the frequency of AC power inputted through the AC power input unit 21. For example, in a country or region where an NTSC system television is used, 60 Hz is used. Since an AC power supply of frequency is used, the frequency detector 20 detects a 60 Hz frequency from the AC power supply.

In the PLL 19, the 60 Hz frequency detected by the frequency detector 20 and the clock frequency generated by the clock oscillator 17 are synchronized, for example, the clock oscillator 17. In Fig. 2, since a clock frequency of 59.94 Hz is generated, a clock frequency of 59.94 Hz is directly applied to the CD drive unit 15 while a fluorescent lamp of 120 Hz is used as the light emission as shown in FIG. In this case, the light emission period of the fluorescent lamp and the exposure time period of the CD become inconsistent with each other.

As a result, a frequency difference of 0.06 Hz occurs between the clock frequency (59.94 Hz) and the emission illumination frequency (120 Hz / 2 = 60 Hz), so that color components of the camera photographed image are distorted. Rolling) 'phenomenon, in order to eliminate such color rolling phenomenon, in the PL 19, the 60Hz frequency detected by the frequency detector 20 and the clock oscillator 17 The 59.94Hz frequency is synchronized to be applied as a vertical drive (VD) signal of the CD driver 15.

Therefore, using the AC power source having the same power source frequency as the AC power source used for the luminescent lighting such as the fluorescent lamp as the system power source of the camera, and using the power source frequency of the AC power source, the clock frequency is the light emission illumination frequency. By synchronizing with, the color rolling phenomenon can be eliminated.

However, when the AC power is not used as described above, when the battery power of the DC component is used in the camera, for example, the same power source frequency as the emitted light cannot be detected and the color rolling phenomenon is eliminated. A problem arises that cannot be done.

Therefore, the present invention was created to solve the above problems, for example, after directly receiving and detecting the frequency of the emission light, such as a fluorescent lamp used for camera shooting, using a phototransistor, etc. SUMMARY OF THE INVENTION An object of the present invention is to provide a color rolling removing apparatus and method for a camera for synchronizing with a clock frequency so that color rolling can be efficiently removed even when no AC power is used.

Color rolling removal apparatus of the camera according to the present invention for achieving the above object, the receiving means for receiving a light emission used for camera shooting; Detection means for detecting an illumination frequency corresponding to the received luminescent illumination; Synchronizing means for synchronizing the detected illumination frequency with the clock frequency of the camera; And driving means for driving the CD vertical drive signal at the synchronized frequency to remove color rolling of the camera.

In addition, the receiving means is a phototransistor for receiving a 120Hz fluorescent lamp illumination used for camera photographing and converting it into an electrical signal, the detection means for detecting an illumination frequency of 60Hz corresponding to the received light emission The monostable multivibrator, wherein the synchronization means is a PEL circuit for synchronizing the detected illumination frequency of 60 Hz and the clock frequency of 59.94 Hz of the camera, and the drive means synchronizes the CD vertical drive signal with the synchronization. Drive at a frequency of 60 Hz, and further comprising on / off means for automatically turning off the synchronization operation with the clock frequency if the illumination frequency is not normally detected.

In addition, the method of removing color rolling of the camera according to the present invention comprises: a step of directly receiving an emission light used for photographing a camera and detecting an illumination frequency corresponding to the emission light; And synchronizing the detected illumination frequency with the clock frequency of the camera to remove color rolling.

In addition, the first step is to directly receive a 120Hz fluorescent lamp used for camera shooting, to detect an illumination frequency of 60Hz, the second step is the detected 60Hz illumination frequency and 59.94Hz clock of the camera Synchronizing the frequencies to remove color rolling, and if the illumination frequency is not normally detected, automatically turning off the synchronization operation with the clock frequency, wherein the camera comprises a battery of direct current component. Using a power source, the color rolling is characterized in that the vertical drive signal of the camera CD (CCD) is driven at 60 Hz and removed.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the color rolling removal apparatus and method of the camera according to the present invention will be described in detail.

First, the color rolling removing apparatus and method according to the present invention can be applied to various types of cameras. For example, in the camera to which the present invention is applied, as shown in FIG. (IRIS) 31, CD (CCD) 32, automatic gain adjuster 33, digital signal processor 34, CD driver 35, microcomputer 36, clock oscillator 37, memory ( 38, the PLL 39 and the frequency detector 40 are included, and the phototransistor 41 and the PEL on / off switching unit 42 are included.

In addition, the microcomputer 36 performs a camera photographing operation according to a user's request, and the light incident on the CD 32 through the lens 30 and the iris 31 is photoelectric as an electric signal. After the conversion, it is input to the digital signal processor 34 via the automatic gain adjuster 33.

On the other hand, the phototransistor 41, for example, as shown in Figure 3, may be installed in a position adjacent to the front end of the CD 32, or may be installed in the outer portion facing the shooting direction of the camera. As such, it may be used as a photo diode or the like.

In addition, the phototransistor 41 directly receives luminescent light used for camera photographing, converts the light into an electrical signal, and outputs the signal to the frequency detector 40. For example, as shown in FIG. Likewise, a conventional amplifier (unsigned) and an RC filter (unsigned) are provided between the phototransistor 35 and the frequency detector 40 to output an illumination frequency signal of 120 Hz output from the phototransistor 41. After amplifying the level and removing unnecessary noise components, the frequency detector 40 is input to the frequency detector 40.

For example, as shown in FIG. 4, the frequency detector 40 may be a mono stable multi vibrator. When the illumination frequency signal of 120 Hz is input, the frequency detector 40 may be used. In 40), a trigger is generated to detect an illumination frequency signal of 60 Hz.

For example, as shown in Fig. 5, in the above-mentioned monostable multivibrator, when all three-phase power supplies emit light, a light emission waveform with a period corresponding to six times the power source frequency is generated to generate a trigger signal. On the basis of the basic emission frequency, the first trigger after the Q output is terminated is selected, and the delay time of the monostable multivibrator is maintained until just before the next period, for example, less than one sixth of the basic emission period. During the set delay time, the input trigger signal is ignored.

Therefore, even if the three-phase power source emits light at the same time, the trigger is generated only for the signal of the basic light emission period, and the trigger signal is used as the reference signal of the PEL. If the illumination frequency of 60 Hz is not normally detected through the same process, it is determined that the emitted light is temporarily blocked by any particular object or the like, and the PLL 39 is automatically turned off.

That is, when the illumination frequency of 60 Hz is normally detected by the frequency detector 40, the PEL 39 synchronizes the clock frequency of 59.94 Hz generated by the clock oscillator 37 with the illumination frequency of 60 Hz. By outputting to the CD drive unit 35, the CD vertical drive (VD) signal corresponding to the exposure time of the CD can be driven at the same 60 Hz frequency as that of the emitting light such as a fluorescent lamp. Therefore, it is possible to efficiently eliminate the color rolling phenomenon caused by the difference between the frequency of the light emitted and the camera clock frequency.

In addition, when the light emission is temporarily blocked by the specific object or the like, by turning off the PEL operation automatically, it is possible to prevent an error from occurring in the synchronization operation between the clock frequency and the illumination frequency. In the above description, preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and those skilled in the art will recognize that various modifications can be made within the spirit and technical scope of the present invention disclosed in the appended claims. Improvements, changes, substitutions or additions to the embodiments will be possible.

The color rolling removing apparatus and method of the camera according to the present invention as described above, for example, after directly receiving and detecting the frequency of the emission light, such as a fluorescent lamp used for camera shooting, using a phototransistor, etc. By synchronizing with the clock frequency of, the color rolling phenomenon can be efficiently eliminated even when AC power is not used, and the illumination frequency and the clock frequency when the luminous illumination is temporarily cut off by any specific object or the like. By automatically turning off the synchronization operation between the two, it is a very useful invention that can prevent the error occurrence of the color rolling removal operation in advance.

Claims (11)

Receiving means for receiving luminescent illumination used for camera photography; Detection means for detecting an illumination frequency corresponding to the received luminescent illumination; Synchronizing means for synchronizing the detected illumination frequency with the clock frequency of the camera; And And driving means for driving a CD vertical drive signal at the synchronized frequency to remove color rolling of the camera. The method of claim 1, The receiving means is a color rolling removal device of a camera, characterized in that for receiving the 120Hz fluorescent lamp illumination used for photographing the phototransistor converted to an electrical signal. The method of claim 1, And the detecting means is a monostable multivibrator for detecting an illumination frequency of 60 Hz corresponding to the received luminous illumination. The method of claim 1, And the synchronizing means is a PEL circuit for synchronizing the detected illumination frequency of 60 Hz with the clock frequency of 59.94 Hz of the camera. The method of claim 1, And said driving means drives said CD vertical drive signal at said synchronized frequency of 60 Hz. The method of claim 1, And on / off means for automatically turning off the synchronization operation with the clock frequency when the illumination frequency is not normally detected. Receiving a light emitting light used for photographing a camera directly and detecting an illumination frequency corresponding to the light emitting light; And And removing the color rolling by synchronizing the detected illumination frequency with the clock frequency of the camera. The method of claim 7, wherein The first step is to directly receive a fluorescent light of 120Hz used for camera shooting, the color rolling removal method of the camera, characterized in that for detecting an illumination frequency of 60Hz. The method of claim 8, The second step, the color rolling removal method of the camera, characterized in that to remove the color rolling by synchronizing the detected illumination frequency of 60Hz and the clock frequency of 59.94Hz of the camera. The method of claim 7, wherein And automatically turning off a synchronization operation with the clock frequency when the illumination frequency is not detected normally. The method of claim 7, wherein The camera uses a battery power of a direct current component, and the color rolling is removed by driving the vertical drive signal of the camera CD (CCD) at 60 Hz.

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