JPH0823461A - Video camera - Google Patents

Abstract

PURPOSE:To obtain a video camera having an image display section in which an excellent image is displayed independently of an image pickup state. CONSTITUTION:Image pickup signals R, G, B of an image pickup element 4 are fed to a video signal processing section 6a via AGC circuits 5R, 5G, 5B. The processing section 6a generates a video signal SV, which is fed to an LCD drive control section 14 and the data signal SD representing the luminance and the color temperature or the like is fed to a camera microcomputer 8. The camera microcomputer 8 discriminates the image pickup mode to apply the image pickup mode signal SM to a mode microcomputer 21 to decide gamma correction data, contrast correction data and white balance correction data, and the correction data signal SCD is fed to a D/A converter section 13. The conversion section 13 converts data for gamma correction, contrast correction and white balance correction of a correction data signal SCD into analog correction signals Sr, SCN, SWB, which are fed to a drive control section 14, in which correction is made for the video signal sv. The image based on the corrected video signal is made on an LCD display section 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera having an image display section composed of a liquid crystal display element.

[0002]

2. Description of the Related Art Conventionally, in order to confirm a photographed image of a video camera, the photographed image has been displayed on an electronic viewfinder of the video camera or a monitor TV connected to the outside. However, since the electronic viewfinder has a small display screen, it is not possible for a plurality of people to check the captured image at the same time. Further, when connecting a monitor TV or the like to the outside, it is necessary to connect a cable or to supply power to the monitor TV, which makes the operation of connection and the like very complicated. Therefore, there is known a display-integrated video camera in which a video camera and a display for confirming a captured image, for example, a display using a liquid crystal display element are integrally attached. FIG. 4 shows the configuration of a conventional video camera.

In FIG. 4, reference numeral 1 is a camera section. The optical image of the subject is formed on the image pickup surface of the image pickup device (for example, CCD) 4 by the lens 2 of the camera unit 1. Further, an iris section 3 is arranged between the lens 2 and the image sensor 4 to control the amount of light to the image sensor 4.

In the image pickup device 4, the optical image formed on the image pickup surface is converted into an image pickup signal. This image pickup signal is, for example, 3
The primary color signals R, G, B are formed. Three primary color signals R, G,
B is gain-controlled by the AGC circuits 5R, 5G, and 5B, and is supplied to the video signal processing unit 6.

In the video signal processing section 6, the AGC circuit 5R,
The video signal SV is formed based on the three primary color signals R, G, B supplied via 5G, 5B, and the LCD of the display unit 10 is displayed.
It is supplied to the drive unit 11. Further, the control signals SCR, SCG, and SCB from the video signal processing unit 6 are transmitted to the AGC circuits 5R, 5G, and 5C.
B is supplied to B to control the gain of each of the AGC circuits 5R, 5G and 5B. Further, the control signal SIR is supplied from the video signal processing unit 6 to the exposure control unit 7, and the control signal SIR is supplied.
The drive control of the iris unit 3 described above is performed based on the IR.

In the LCD drive unit 11 to which the video signal SV is supplied from the video signal processing unit 6, the video signal SV is a drive signal DR of the LCD display unit 12 constituted by a liquid crystal display element.
Is converted to. A captured image is displayed on the LCD display unit 12 by the drive signal DR.

[0007]

By the way, this LCD
The display unit 12 is C in terms of dynamic range and gradation characteristics.
It is inferior to the RT and the display image has a drawback that it is a picture that is difficult to see in terms of image quality as compared with the CRT. Also, since it is used in various environments by being integrated with a video camera, for example, when the surroundings are very bright, the contrast decreases and the display screen becomes difficult to see, and the hue varies depending on the color temperature of the illumination light. It may change. Further, when the subject is dark or very bright, the gradation of the display screen is lowered. Therefore, in order to obtain a good display image, it is necessary to change the brightness, contrast, hue, etc. of the display screen of the LCD display unit 12 each time, and the operation is very complicated.

Therefore, the present invention provides a video camera having an image display section capable of displaying an excellent image regardless of the photographing condition or the condition of the subject.

[0009]

A video camera according to claim 1, which is a video camera having a liquid crystal display portion for displaying an image, wherein the state discrimination is performed for discriminating the brightness of a photographing state based on an image pickup signal. Means and a display signal control means for controlling the image signal supplied to the liquid crystal display section, and based on the discrimination signal of the state discrimination means, the display signal control means performs the contrast correction of the image signal, and the liquid crystal display section. It controls the contrast of the image displayed on.

A video camera according to a second aspect of the present invention is a video camera having a liquid crystal display section for displaying an image, and a state determination means for determining a signal level of an image pickup signal,
Display signal control means for controlling the image signal supplied to the liquid crystal display section, and based on the determination signal of the state determination means,
The display signal control means performs gamma correction on the image signal to control the gradation of the image displayed on the liquid crystal display unit.

A video camera according to a third aspect of the present invention is a video camera having a liquid crystal display section for displaying an image, wherein the state discrimination means for discriminating the white balance of the image pickup signal and the image supplied to the liquid crystal display section. Display signal control means for controlling the signal, and based on the discrimination signal of the state discrimination means, the display signal control means performs white balance correction of the image signal to control the white balance of the image displayed on the liquid crystal display unit. To do.

[0012]

According to the first aspect of the present invention, the brightness of the photographing state is discriminated by the state discriminating means, and the display signal control means performs the contrast correction of the image signal based on the discriminating signal. The contrast of the image displayed on the section is controlled. Therefore, the contrast of the display screen of the liquid crystal display unit is emphasized, and a good display screen can be obtained even if the surroundings are bright. Moreover, since the contrast of the display screen is automatically controlled, the operation can be very simple.

According to the second aspect of the present invention, the signal level of the image pickup signal is discriminated by the state discriminating means, and the display signal control means performs the gamma correction of the image signal based on the discriminating signal, whereby the liquid crystal display section. The gradation of the image displayed on the screen is controlled. Therefore, it is possible to obtain a display screen having good gradation characteristics even when the subject is dark or very bright. Moreover, since the gradation of the display screen is automatically controlled, the operation can be very simple.

According to the third aspect of the invention, the white balance of the image pickup signal is discriminated by the state discriminating means, and the display signal control means performs the white balance correction of the image signal based on the discriminating signal, whereby the liquid crystal display is performed. The white balance of the image displayed on the copy is controlled. For this reason,
It is possible to obtain a good display screen that is not bluish or reddish. Further, since the white balance of the display screen is automatically controlled, the operation can be made very simple.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a display-integrated video camera using an LCD display device according to the present invention will be described below with reference to FIG. In FIG. 1, parts corresponding to those in FIG. 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

The signal processing unit 6a shown in FIG. 1 corresponds to the signal processing unit 6 of FIG. 4, and from this signal processing unit 6a, a data signal SD indicating brightness, color temperature, etc. is sent to the camera control microcomputer ( (Hereinafter referred to as "camera microcomputer").

The camera microcomputer 8 determines the photographing state (for example, indoor or outdoor) based on the supplied data signal SD. A shooting mode signal SM indicating the shooting state is supplied to a mode control microcomputer (hereinafter referred to as “mode microcomputer”) 21 of the VTR unit 20. In addition, the control signal SIR from the camera microcomputer 8
Is supplied to the exposure control unit 7 to control the drive of the iris unit 3.

The mode microcomputer 21 determines γ correction data, contrast correction data, and white balance correction data based on the supplied shooting mode signal SM.
Correction data signal SCD composed of these correction data
Is supplied to the D / A conversion unit 13 of the display unit 10a.

In the D / A converter 13, the correction data signal S
The γ correction data, contrast correction data, and white balance correction data of the CD are the analog correction signal S, respectively.
It is converted into r, SCN, and SWB and supplied to the LCD drive control unit 14.

The LCD drive control unit 14 includes a γ correction circuit 14
r, the contrast correction circuit 14c, the white balance correction circuit 14w, and the control unit 14d, and the γ correction circuit 1
At 4r, γ correction is performed on the video signal Sv supplied from the video signal processing unit 6a according to the analog correction signal Sr supplied from the D / A converter 13. The contrast correction circuit 14c performs contrast correction on the video signal Sv supplied from the video signal processing unit 6a according to the analog correction signal SCN. Similarly, in the white balance correction circuit 14w, the video signal Sv supplied from the video signal processing unit 6a in accordance with the analog correction signal SWB.
Is corrected.

The corrected video signal is converted into a drive signal DR for the LCD display unit 12 by the control unit 14d and supplied to the LCD display unit 12 to display an image on the LCD display unit 12. . In the above-described embodiment, the camera microcomputer 8 and the mode microcomputer 21 are used to perform the correction control of the video signal Sv.
It goes without saying that the correction control may be performed by one microcomputer.

This embodiment is constructed as described above,
For example, when the shooting location moves from indoor to outdoor and the ambient brightness increases, the contrast of the display screen of the LCD display unit 12 decreases. Therefore, when it is detected that the brightness is increased by the brightness information of the data signal SD supplied from the signal processing unit 6a, the LCD drive control unit 14
Of the video signal Sv by the contrast correction circuit 14c of
It is assumed that the contrast is increased to provide good display on the LCD display unit 12.

FIG. 2 showing the characteristics of the LCD display section 12.
In, when the signal level of the signal input to the LCD display unit 12 is extremely low (when the subject is entirely dark) or high (when the subject is very bright overall), the It is not possible to obtain a display screen having good gradation characteristics with little change in light transmittance of the display element.

Therefore, according to the brightness information of the data signal SD supplied from the signal processing unit 6a, in the γ correction circuit 14r, when the object is dark, the signal in the portion where the signal level of the input signal is low as shown in FIG. 3A. A large change in level is converted into a change in signal level. Since the output signal after this conversion is supplied to the LCD display unit 12, it is possible to obtain a display screen having good gradation characteristics even when the subject is dark. If the subject is very bright,
As shown in B, the change of the signal level in the portion where the signal level of the input signal is high is converted into the change of the signal level,
The converted output signal makes it possible to obtain a display screen having good gradation characteristics even when the subject is very bright. Of course, the conversion operation shown in FIGS. 3A and 3B may be combined to obtain an output signal by converting an input signal as shown in FIG. 3C.

When the color temperature of the illumination light is high, the display screen of the LCD display section 12 is bluish, and when the color temperature is low, it is reddish. It Therefore, the change in color temperature is detected by the color information of the data signal SD supplied from the signal processing unit 6a, and LC
The white balance correction circuit 14w of the D drive control unit 14 can change the white balance of the video signal Sv to obtain a good display screen which is not bluish or reddish on the LCD display unit 12.

As described above, according to this example, even if the photographing environment changes, the display is automatically controlled to monitor the change of the photographing environment so that a good display can be made. It is not necessary to manually operate the hue and the like, and the operation can be very simple.

[0027]

According to the first aspect of the present invention, the brightness of the photographing state is discriminated by the state discrimination means, and the display signal control means performs the contrast correction of the image signal based on the discrimination signal. The contrast of the image displayed on the liquid crystal display unit is controlled. Therefore, the contrast of the display screen of the liquid crystal display unit is emphasized, and a good display screen can be obtained even if the surroundings are bright. Further, since the contrast of the display screen is automatically controlled, the operation can be very simple.

According to the second aspect of the present invention, the signal level of the image pickup signal is discriminated by the state discriminating means, and the display signal control means performs the gamma correction of the image signal based on the discriminating signal, whereby the liquid crystal display section. The gradation of the image displayed on the screen is controlled. Therefore, it is possible to obtain a display screen having good gradation characteristics even when the subject is dark or very bright. Moreover, since the gradation of the display screen is automatically controlled, the operation can be very simple.

According to the third aspect of the invention, the white balance of the image pickup signal is discriminated by the state discriminating means, and the display signal control means performs the white balance correction of the image signal based on the discriminating signal, whereby the liquid crystal display is performed. The white balance of the image displayed on the copy is controlled. For this reason,
It is possible to obtain a good display screen that is not bluish or reddish. Moreover, since the white balance of the display screen is automatically controlled, the operation can be very simple.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a video camera according to the present invention.

FIG. 2 is a diagram showing characteristics of an LCD display unit.

FIG. 3 is a diagram showing characteristics of a γ correction circuit.

FIG. 4 is a diagram showing a configuration example of a conventional video camera.

[Explanation of symbols]

 1, 1a Camera section 2 Lens 3 Iris section 4 Image sensor 5R, 5G, 5B AGC circuit 6, 6a Video signal processing section 7 Exposure control section 8 Camera control microcomputer 10, 10a Display section 11 LCD drive section 12 LCD display section 13 D / A converter 14 LCD drive control unit 14c Contrast correction circuit 14d Control unit 14r γ correction circuit 14w White balance correction circuit 20 VTR unit 21 Mode control microcomputer

Claims (3)

[Claims] 1. A video camera having a liquid crystal display unit for displaying an image, wherein a state determination means for determining the brightness of a shooting state based on an image pickup signal and an image signal supplied to the liquid crystal display unit are controlled. Display signal control means for controlling the contrast of the image displayed on the liquid crystal display unit by performing contrast correction of the image signal by the display signal control means based on the determination signal of the state determination means. Video camera characterized by. 2. A video camera having a liquid crystal display section for displaying an image, a state determining means for determining a signal level of an image pickup signal, and a display signal control means for controlling an image signal supplied to the liquid crystal display section. The display signal control means performs gamma correction on the image signal based on the determination signal of the state determination means, and controls the gradation of the image displayed on the liquid crystal display unit. Video camera. 3. A video camera having a liquid crystal display section for displaying an image, a state determining means for determining a white balance of an image pickup signal, and a display signal control means for controlling an image signal supplied to the liquid crystal display section. The display signal control means performs white balance correction of the image signal based on the determination signal of the state determination means, and controls the white balance of the image displayed on the liquid crystal display unit. A video camera.