JP2000270339A - Television camera apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set the luminance variation of a video caused by the variation of an incident light quantity almost constant by sampling the video signal of a selected necessary area in the video signals whose signal levels are only the maximum value, thereby controlling an iris by a simulated video signal outputted based on necessary weighted data. SOLUTION: Incident light from an image pickup lens 1 provided with the iris is color-resolved into RGB three primary-color light by a color conversion prism, photoelectrically converted and to respectively output respective R, G and B video signals by image-pickup elements 3R, 3G and 3B. These respective video signals are respectively processed and outputted by a correlated double sampling circuit/low-pass filter 4, a preamplifier 5, a gain control amplifier circuit 6 and a non-additive mixing circuit 8. A simulated signal generation circuit 11 controls the iris by generating the simulated video signal by data obtained by allowing a sampling part 10 to sample the necessary area of this output to give necessary weighting under the control of a CPU 9. Thus, a video signal processing part 7 nearly fixes the luminance variation of video.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television camera device having an image pickup lens provided with an iris for controlling the amount of light by using a video signal as an input signal, and more particularly, to an image pickup lens based on a video signal of an arbitrary designated required image area. And a television camera device in which the change in the amount of incident light is made substantially constant.

[0002]

2. Description of the Related Art In general, a television camera device controls a video signal output level to a substantially constant output level even when the amount of incident light from an imaging lens changes due to a change in illuminance of a subject being imaged. Means. Conventionally, control means for controlling the video signal output level of the television camera device to a substantially constant output level include control means for controlling the iris of the imaging lens and control means for controlling the gain of the video signal amplifier circuit. Has been put to practical use. The control means for controlling the iris of the imaging lens includes detecting a change in a video signal level due to a change in the amount of light incident on the television camera apparatus from a subject, and automatically controlling the iris of the imaging lens based on the detection signal. Control means for adjusting the amount of incident light is often used.
In controlling the iris of the imaging lens, a change in the image signal level due to a change in the amount of light incident from the subject is detected as a detection signal in the television camera apparatus body, and an iris control signal (DC) is generated based on the detection signal. Means for transmitting an iris control signal from the television camera apparatus main body to the iris of the imaging lens to control the aperture of the iris, and a signal level from the television camera apparatus main body changes due to a change in the amount of light incident from the subject. The video signal is sent to the iris of the imaging lens, and a change in the video signal level is detected as a detection signal by an iris control circuit provided in the iris of the imaging lens, and an iris control signal is generated based on the detection signal to generate an iris of the imaging lens. There is a means for controlling the aperture.

FIG. 2 is a block diagram of a conventional television camera apparatus in which a video signal whose signal level is changed is sent to an iris of an imaging lens to control the iris, and the prior art will be described. FIG. 2 shows an imaging lens 21 provided with an iris control circuit provided with an iris controlled by an input video signal, and a red (hereinafter, R and R) attached to a color separation optical device (color separation prism) 22. ), Green (hereinafter referred to as G), blue (hereinafter referred to as B)
), For example, a CCD 2 of a solid-state image sensor
3 and a CDS (correlated double sampling) circuit / LPF (low-pass filter) for reducing noise contained in R, G, and B video signals photoelectrically converted and output from the R, G, and B image sensors 23. ) 24, a preamplifier 25 for amplifying each of the R, G, and B video signals with reduced noise to a predetermined level, and each of the R, G, and B video signals amplified to a predetermined level for each of R, G, and B video signals. A gain control amplifier circuit 26 that performs gain control so as to be a signal; and performs signal processing such as detail correction, gamma correction, and masking on the required levels of R, G, and B video signals, and performs predetermined levels of R, G, and B signals. A video signal processing unit 27 for outputting a video signal;
A NAM (non-additive mixing) circuit 28 for generating a video signal having a maximum signal level only in each video signal, and a weighting control section for weighting the video signal having a maximum signal level only and outputting to the iris (For example, a CPU: central processing unit) 29. It should be noted that the block diagram of the television camera device shown in FIG. 2 mainly describes a circuit relating to iris control, and the other components are omitted.

In a television camera device, incident light from a subject which has passed through an imaging lens 21 provided with an iris for controlling the amount of light by an input video signal enters a color separation prism 22, ,
The light is separated into three primary colors of G and B, and the R light is
The R and G lights enter the CCD 23G, and the B light enters the CCD 23B. Each of the CCDs 23R, 23G, and 23B attached to the color separation prism 22 photoelectrically converts the light of the three primary colors of R, G, and B, which is color-separated by the color separation prism 22 and enters, into a video signal. R, G,
B Each video signal is output to a plurality of CDS circuits / LPFs 24. Each CDS circuit / LPF 24 includes a CCD 23R, 23
The thermal noise, 1 / f noise, and the like included in each of the R, G, and B video signals input from G and 23B are reduced and output to a plurality of preamplifier circuits 25.

[0005] Each preamplifier circuit 25 is connected to each CDS circuit /
The R, G, and B video signals reduced in noise inputted from the LPF 24 are amplified to a predetermined level with low noise, and the amplified predetermined R, G, and B video signals are output to a plurality of gain control amplifier circuits 26. I do. Each gain control amplifier circuit 26 has a predetermined level of R, G,
The gain control is performed on each of the B video signals so that the required levels of R, G, and B video signals are obtained.
G and B video signals are processed by a plurality of video signal
Output to the circuit 28.

On the other hand, each video signal processing section 27 performs required signal processing such as detail correction, gamma correction, masking and the like on the required level R, G, B video signals input from each gain control amplifier circuit 26 respectively. Then, the R, G, and B video signals that have undergone the required signal processing are output to other circuits.
The other NAM circuit 28 performs non-additive mixing of the required levels of R, G, and B video signals input from the respective gain control amplifier circuits 26, and among the R, G, and B video signals,
A video signal whose signal level is only the maximum value is generated, and the generated video signal whose signal level is only the maximum value is weighted by the weight control unit 2.
9 is output.

The weighting control unit 29 uses a peak value, an average value, or data emphasizing the video signal in the center area of the video as the video signal having the maximum signal level only from the NAM circuit 28. The required weighting is performed, and the video signal that has been subjected to the required weighting is output to an iris included in the imaging lens 21. The iris included in the imaging lens 21 is provided with an iris control circuit, detects a change in the level of a video signal that has been weighted and input from the weight control unit 29 as a detection signal, and detects an iris control signal based on the detection signal. Is generated, and the aperture of the iris is properly controlled. At this time, the weighting control unit 29 controls the iris of the imaging lens 21 so that the signal level of the video signal with the required weighting becomes substantially constant, so that the amount of incident light from the subject to the television camera device becomes appropriate. Adjust as follows.

[0008]

A television camera device according to the prior art is provided with an iris for controlling the amount of light incident on an imaging lens in accordance with an input video signal, and a peak value or an average value of the video signal, Alternatively, data that emphasizes the video signal in the center area of the video and data detected from the entire video are used to perform necessary weighting to control the iris of the imaging lens. There is a problem that the luminance level of the image changes each time a high luminance portion or a low luminance portion enters. The present invention solves the above problems,
The iris of the imaging lens is controlled based on the video signal of the required area arbitrarily specified in the image being captured, and even if a high-luminance part or a low-luminance part enters the captured image, It is an object of the present invention to provide a television camera device capable of making a change in luminance of an image due to a change in light amount substantially constant.

[0009]

In order to achieve the above object, a television camera device according to the present invention comprises:
An imaging lens provided with an iris that controls the amount of light according to an input video signal, and a non-additive mixing circuit that performs non-additive mixing of red, green, and blue video signals and outputs a video signal having only a maximum signal level. A weighting control unit that samples a video signal of a selected required area among the video signals having the maximum signal level only and outputs a simulated video signal based on data obtained by performing a required weighting. And controlling the iris by the simulated video signal to control the amount of light passing through the imaging lens, so that the level change of the video signal becomes substantially constant.

More specifically, in the television camera device of the present invention, the weighting control section selects and selects a video signal of a required area in the video being picked up from the video signals having the maximum signal level only. A central processing unit for controlling the weighting of the video signal of the selected required area; and a central processing unit that selects from the video signals having the maximum signal level only, A required weighting is applied to data obtained by sampling the video signal in the required area of the required area, and a sampling unit that outputs the required weighted data, and a simulation based on the required weighted data output from the sampling unit. And a simulation signal generating section for generating a video signal and outputting the simulation video signal.

Further, the television camera device of the present invention has an image pickup lens provided with an iris for controlling the amount of light according to an input video signal, and converts incident light from the image pickup lens into red, green and blue light. A color separation optical device for separating the light, a plurality of image sensors for photoelectrically converting the three color lights of red, green, and blue and outputting red, green, and blue video signals;
A non-additive mixing circuit that performs non-additive mixing of each of the video signals and outputs a video signal whose signal level is only the maximum value, selection of a video signal of a required area in a video being captured, and selection of the selected video signal A central processing unit that controls the weighting of the video signal, and the video signal whose input signal level from the non-additive mixing circuit is only the maximum value is included in the video imaged under the control of the central processing unit. A sampling unit that samples a video signal in a required area and sets the weighted data as required, and a simulation signal generator that outputs a simulated video signal based on the required weighted data input from the sampling unit; And an iris of the imaging lens is provided by the simulated video signal corresponding to a video signal of a required area in a captured video input from the simulated signal generation unit. It is intended to control.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a television camera device according to the present invention will be described with reference to FIG.
In FIG. 1, reference numeral 1 denotes an imaging lens provided with an iris control circuit and provided with an iris controlled by an input video signal, and 2 denotes incident light from a subject incident from the imaging lens 1 on R, G, A color separation prism 3 for color separation into light of the B3 primary color, 3 for red (hereinafter referred to as R), green (hereinafter referred to as G), and blue (hereinafter referred to as B) attached to the color separation prism 2 Each image sensor, for example, C of the solid-state image sensor
The CDs 4 are CDSs (Correlated Double Sas) that reduce sampling noise and the like included in R, G, and B video signals that are photoelectrically converted and output from the R, G, and B image sensors 3.
mpling: correlated double sampling) circuit / LPF, 5
The preamplifier 6 amplifies each of the R, G, and B video signals with reduced noise to a predetermined level with low noise. The preamplifier 6 converts the R, G, and B video signals amplified to the predetermined level into R, G, and B at required levels.
A gain control amplifier circuit 7 for performing gain control amplification so as to be each video signal, performs required signal processing such as detail correction, gamma correction, masking, and the like on each of the required levels of R, G, and B video signals, and performs predetermined level R processing. , G, B video signal processing section, 8 is a NAM (non-additive mixture) for generating a video signal in which the signal level among the required levels of R, G, B video signals is only the maximum value The circuit 9 includes a CPU (Central Processing Unit) that performs various controls such as selection of a video signal of a required area arbitrarily designated in a captured image and weighting control. A sampling unit 11 samples a video signal of a required area arbitrarily designated in the video being captured from video signals having a signal level of only the maximum value, and makes the data weighted as required. The sampled weighted data pulling unit 10 shows a simulated signal generator for generating a simulated image signal for the original to the iris control. Note that the block diagram of the television camera device shown in FIG. 1 mainly describes a circuit relating to iris control, and the other components are omitted.

The operation will be described. In the television camera device of the present invention, incident light from a subject that has passed through an imaging lens 1 having an iris is incident on a color separation prism 2. The color separation prism 2 separates the incident light from the subject incident from the imaging lens 1 into light of three primary colors of R, G, and B, and R light of the separated R, G, and B primary light. Is C
The CD3R and G lights are incident on the CCD 3G, and the B light is incident on the CCD 3B. Each of the CCDs 3R, 3G, and 3B attached to the color separation prism 2 photoelectrically converts the light of the three primary colors of R, G, and B, which is color-separated from the color separation prism 2 and enters, into a video signal. The R, G, and B video signals are output to each of the plurality of CDS circuits / LPFs 4. Each CDS circuit / LPF4 has a plurality of CCD3Rs,
Thermal noise, 1 / f noise, and the like included in each of the R, G, and B video signals input from 3G and 3B are reduced and output to a plurality of preamplifier circuits 5.

Each of the preamplifier circuits 5 includes R, G, and B with reduced noise input from the plurality of CDS circuits / LPFs 4.
Each video signal is amplified to a predetermined level with low noise, and the amplified predetermined level R, G, B video signals are output to a plurality of gain control amplifier circuits 6. Each gain control amplifier circuit 6 has a predetermined level of R, G,
Each of the B video signals is gain-controlled and amplified so as to have required levels of R, G, and B video signals, and the gain-controlled and amplified required-level R, G, and B video signals are converted into a plurality of video signal processing units 7 and N
Output to the AM circuit 8.

On the other hand, each of the video signal processing units 7 converts a required level of R, G, and B video signals input from each of the plurality of gain control amplifier circuits 6 into a required signal such as a detail correction, a gamma correction, and masking. After processing, the R, G, and B video signals of a predetermined level that have undergone the required signal processing are output to other circuits. The other NAM circuit 8 has the required levels of R, G,
The non-additive mixing of each B video signal is performed, and among the R, G, and B video signals, a video signal whose signal level is only the maximum value is generated, and the generated video signal whose signal level is only the maximum value is sampled. Output to 10

The sampling section 10 samples a video signal of a required area in a video being picked up from a video signal whose signal level inputted from the NAM circuit 8 is only the maximum value under the control of the CPU 9, The required weighting is performed to obtain the required weighted data, and the required weighted data of the required area in the captured video is output to the simulation signal generator 11. The simulation signal generator 11 generates a simulation video signal, for example, a square wave in a horizontal cycle based on data with a predetermined weight, for example, data of a DC level input from the sampling unit 10,
The simulated video signal for controlling the generated iris is transferred to the imaging lens 1.
Output to the iris in preparation for.

The iris provided in the imaging lens 1 is provided with an iris control circuit, and the iris control circuit provided in the iris detects a change in the level of a simulated video signal input from the simulated signal generator 11 as a detection signal. And an iris control signal is generated based on the detection signal, and the iris aperture is appropriately controlled by the iris control signal. At this time, the iris provided in the imaging lens 1 is
It is controlled by the signal level of the video signal in a required area in the video being captured, and adjusts the amount of incident light that enters from the subject and passes through the imaging lens 1.

[0018]

According to the present invention, the iris of the imaging lens is controlled based on a video signal of a required area arbitrarily designated in the video being captured, and
It is possible to provide a television camera device in which a change in the luminance of an image due to a change in the amount of incident light can be made substantially constant even when a high-brightness portion or a low-brightness portion enters.

[Brief description of the drawings]

FIG. 1 is a block diagram of a television camera device according to the present invention.

FIG. 2 is a block diagram of a television camera device according to the related art.

[Explanation of symbols]

1, 21 imaging lens with iris, 2, 22 color conversion prism, 3, 23 imaging device, 4, 24 correlated double sampling circuit / low-pass filter, 5, 25 preamplifier, 6, 26 gain control amplification circuit, 7, 27 video signal processing unit, 8, 28 non-additive mixing circuit, 9 central processing unit, 10 sampling unit, 11 simulation signal generation unit, 29 weight control unit.

Claims (3)

[Claims] At least an imaging lens provided with an iris for controlling a light amount according to an input video signal;
A non-additive mixing circuit that performs non-additive mixing of each of the green and blue video signals and outputs a video signal whose signal level is only the maximum value. A weighting control unit that samples a video signal of a selected required area and outputs a simulated video signal based on data that has been weighted as required, and controls the iris with the simulated video signal to control the imaging lens. A television camera device characterized in that the amount of light passing therethrough is controlled so that the level change of the video signal becomes substantially constant. 2. The television camera device according to claim 1, wherein the weighting control section selects a video signal of a required area in the video being picked up from the video signals having the maximum signal level only. A central processing unit for controlling the weighting of the video signal in the selected required area; and the central processing unit selects from the video signals having the maximum signal level only, and A sampling unit that weights data obtained by sampling the video signal of the required area of the required area and outputs the required weighted data; and a simulation based on the required weighted data output from the sampling unit. A television camera device, comprising: a simulation signal generation unit that generates a video signal and outputs the simulation video signal. 3. An image pickup lens provided with an iris for controlling the amount of light according to an input video signal, a color separation optical device for color separation of incident light from the image pickup lens into three color lights of red, green, and blue; Red, green, and blue light are converted photoelectrically into red, green,
A plurality of image sensors that output blue video signals; a non-additive mixing circuit that performs non-additive mixing of the red, green, and blue video signals and outputs a video signal whose signal level is only the maximum value; A central processing unit for selecting a video signal of a required area in the video and controlling weighting of the selected video signal; and a video signal having only a maximum value of the signal level input from the non-additive mixing circuit. A sampling unit that samples a video signal of a required area in a video being imaged under the control of the central processing unit from the inside and converts the signal into data with a required weight; and the required weight input from the sampling unit. A simulation signal generation unit for outputting a simulation video signal based on the obtained data, and a video signal of a required area in a captured image input from the simulation signal generation unit. Television camera apparatus and controls the iris of the imaging lens by the video signal of the corresponding simulated.