JPH05191687A - Image pickup device - Google Patents

Abstract

PURPOSE:To provide an image pickup device which faithfully follows the color temperature change of external light and reproduces a proper color. CONSTITUTION:This device is provided with a spectrum intensity detecting means 1 which detects the intensity of the wavelength spectrum of external light, a spectrum intensity control means 2 which controls the intensity of the wavelength spectrum of a color view finder 4 in response to the spectrum intensity signal outputted from the spectrum intensity detecting means 1, and a spectrum intensity prescribing means 3 which prescribes the intensity of the wavelength spectrum of the color view finder based on the spectrum intensity control signal from the spectrum intensity control means 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus, and more particularly to a color viewfinder for a video camera which is an image pickup apparatus.

[0002]

2. Description of the Related Art Up to now, in a general-purpose TV, it is only necessary to select a place to install, compare an image of an actual subject with a real-time image of the subject, and rely on human perception to store a hue. I was making a match. On the other hand, in a video camera which is an image pickup device, what kind of place, for example, indoors / outdoors, indoors using incandescent lamps / indoors using fluorescent lamps, or outdoors in a cloudy sky / outdoors in the sunset It is necessary to be able to follow changes in the intensity of the wavelength spectrum of the external light that indicates that there is a change in the color temperature of the image, providing a highly reproducible image by comparing the image of the actual subject with that of the subject in real time. I am able to do it.

[0003]

However, in the video camera which is the conventional image pickup apparatus of this type, since the place where it is used is not selected, the ambient color temperature changes extremely, and for example, 2500K to 10000K (K is In Kelvin, the unit of color temperature was sometimes reached. Therefore, in the conventional color electronic viewfinder (color EVF), especially the color EVF using liquid crystal, if the color temperature of the white balance is fixed to about 6500K in order to improve the operability, the ambient color temperature becomes extremely extreme. There was a problem that it could not follow such changes. That is, in such a color EVF, the liquid crystal becomes reddish as the surrounding color temperature becomes higher, and the liquid crystal becomes bluish as the surrounding color temperature becomes lower. In the color EVF of such a video camera, there is a problem in that a sense of discomfort increases because the difference portion with respect to the intensity change of the wavelength spectrum of the external light, which indicates that the color temperature changes, can be seen in real time.

Therefore, it is an object of the present invention to provide an image pickup apparatus capable of faithfully following a change in the color temperature of external light and capable of reproducing an appropriate color.

[0005]

As a means for solving the above problems, the present invention provides a spectrum intensity detecting means for detecting the intensity of a wavelength spectrum of external light, and a spectrum intensity signal output from the spectrum intensity detecting means. Spectrum intensity control means for controlling the intensity of the wavelength spectrum of the color viewfinder in response to, and spectrum intensity defining means for defining the intensity of the wavelength spectrum of the color viewfinder based on the spectrum intensity control signal from the spectrum intensity control means. It is equipped with and. Preferably, the spectrum intensity detecting means has an external light detecting section, and controls the spectrum intensity controlling means according to a detection output from the external light detecting section. Further, the spectral intensity detection means has a solid-state imaging section, the spectral intensity control means has a white balance control means, and the white balance of the color viewfinder is white based on the imaging signal from the solid-state imaging section. The balance intensity is controlled by the balance control means, and the spectrum intensity is controlled by the spectrum intensity control means based on the control signal from the white balance control means.

[0006]

The intensity of the wavelength spectrum of the external view is detected by the spectrum intensity detecting means, and the intensity of the wavelength spectrum of the color viewfinder is controlled by the spectrum intensity controlling means in response to the spectrum intensity signal output from the spectrum intensity detecting means. To do. Next, the intensity of the wavelength spectrum is defined by the spectrum intensity defining unit based on the spectrum intensity control signal from the spectrum intensity controlling unit. As a result, it is possible to faithfully follow the change in the color temperature of the external light, and it is possible to reproduce an appropriate color. Preferably, the spectrum intensity detecting means is an external light detecting section, and the spectrum intensity controlling means is controlled according to a detection output from the external light detecting section. Further, the spectral intensity detection means is a solid-state imaging unit,
After controlling the white balance of the color viewfinder based on the image pickup signal from the solid-state image pickup section, the spectrum intensity is controlled based on the white balance control signal.

[0007]

EXAMPLE An example of the present invention will be described with reference to FIG. FIG. 1 is a block diagram for explaining the outline of an embodiment of the image pickup apparatus of the present invention. In this figure, reference numeral 1 is a spectrum intensity detecting means for detecting the intensity of the wavelength spectrum of external light. The spectrum intensity control means 2 is
The intensity of the wavelength spectrum of the color viewfinder 4 is controlled in response to the spectral intensity signal 100 output from the spectral intensity detecting means 1. The spectrum intensity defining means 3 defines the intensity of the wavelength spectrum based on the spectrum intensity control signal 101 from the spectrum intensity controlling means 2. The color viewfinder 4 has a base formed of liquid crystal. Since the color of the liquid crystal of the color viewfinder 4 is defined according to the spectrum intensity defining signal 102 from the spectrum intensity defining means 3, it is possible to faithfully follow the change in the color temperature of the external light and reproduce it in an appropriate color. It will be possible.

FIG. 2 is a block diagram showing a concrete configuration of the embodiment of the present invention. In FIG. 2, 5 is a camera unit, 6
Is a color EVF (Electric View Fin)
der) is shown. The spectrum intensity detecting means 1 in FIG.
External light detection unit 1a for detecting (green) and B (blue) respectively
Then, the signal level of R or B for G is measured to detect the wavelength spectrum of the external light corresponding to the color temperature of the external light. The output side of the external light detection unit 1a has an input side of the operational amplifier 7a of the comparator 7 to which the R detection signal and the G detection signal are input and an input side of the operational amplifier 7b of the comparator 7 to which the G detection signal and the B detection signal are input. It is connected. Operational amplifier 7
In a, it is a difference signal between the R detection signal and the G detection signal (R-
G) The signal is output from the comparison unit 7. In addition, the operational amplifier 7b
Is the difference signal between the B detection signal and the G detection signal (B-
G) The signal is output from the comparison unit 7.

The matrix / level controller 8 is
The red color control signal RCONT and the blue color control signal BCONT are output based on the (RG) signal and the (BG) signal which are the difference signals from the operational amplifier 7. The matrix / level controller 8 corresponds to the spectrum intensity control means 2. For example, when the color temperature of the external light rises, the inequality sign of the difference signal becomes (R−G) <(B−G) ... (1), and the matrix / level controller 8
When it is determined that the difference signal between the (RG) signal and the (BG) signal can be represented by an inequality sign as in the equation (1), the output voltage level of the red color control signal RCONT is increased, In addition, the output voltage level of the blue color control signal BCONT is controlled to be lowered. On the other hand, when the color temperature of the external light rises, the inequality sign of the difference signal becomes (RG)> (BG) ... (2), and the matrix / level controller 8
When it is determined that the difference signal between the (RG) signal and the (BG) signal can be represented by an inequality sign as in Expression (2), the output voltage level of the red color control signal RCONT is lowered, In addition, the output voltage level of the blue color control signal BCONT is controlled to be increased.

The correction circuit 9 corrects the outputs of the red color control signal RCONT and the blue color control signal BCONT output from the matrix / level controller 8 using a feedback differential amplifier circuit or the like. Color temperature adjusting volumes 15 and 16 are connected to the output side of the correction circuit 9, and the color temperature is finely adjusted by these adjusting volumes 15 and 16. On the other hand, in addition to this, to the color EVF 6, the red brightness R signal, the green brightness G signal, and the blue brightness B signal corresponding to the respective brightnesses are input to the brightness adjusting unit 11, and the respective colors are supplied. A preamplifier 12 to 1 is provided with a brightness adjustment signal according to the brightness.
4 and amplifies each luminance signal. In the preamplifiers 12 to 14, the amplification output for each color based on the correction output of the correction circuit 9, the fine adjustment of the color temperature by the adjusting volumes 15 and 16 and the brightness adjustment output of the brightness adjusting unit 11 is input to the multiplexer 17. .

The multiplexer 17 controls the amplifiers 18a to 18c of the buffer circuit 18 for each color based on the correction output of the correction circuit 9, the fine adjustment of the color temperature by the adjusting volumes 15 and 16 and the brightness adjustment output of the brightness adjusting section 11. Output image information. The correction circuit 9, the RGB decoder 10, the brightness adjusting unit 11, the preamplifiers 12 to 14, and the adjusting volumes 15 and 16 which are the spectrum intensity defining circuit 30 correspond to the spectrum intensity defining unit 3 in FIG. ..
In the liquid crystal display unit 19, the amplifier 18a of the buffer circuit 18
Image information R _out of each color red, green and blue from
Liquid crystal display is performed based on G _out and B _out . The liquid crystal display unit 19 corresponds to the color viewfinder unit 4.

In the above embodiment, the external light is detected by using the external light detector 1a, and the operational amplifier 7a of the comparator 7 outputs the (R-G) signal which is the difference signal between the R detection signal and the G detection signal. , (R−G) signal which is the difference signal between the R detection signal and the G detection signal is output from the operational amplifier 7b, and the spectrum intensity regulating circuit 30 controls the spectrum intensity by the matrix / level controller 8 based on these output signals It becomes possible to faithfully follow the change in the color temperature of the external light and to enable the appropriate color reproduction by operating the.

FIG. 3 is a block diagram showing the concrete construction of another embodiment of the present invention. The present embodiment and the embodiment of FIG. 2 differ only in the configuration on the camera 5 side, and the color EVF 6
Since the configurations on the side are the same, the same reference numerals are used for the same configurations, and only different configurations will be described. The signal detected by the CCD 1b which is the spectrum intensity detecting means 1 of FIG. 1 is a signal corresponding to each color of Y _e , yellow cyan C _Y , and green G whose gain is controlled by the automatic gain control unit 20 according to the external light. Process matrix section 21 and switch A / D conversion section 2
Enter in 3. The output side of the process matrix section 21 outputs a luminance signal Y, a signal (RY) for obtaining a difference in luminance signal from a red signal, and a signal (BY) for obtaining a difference in luminance signal from a blue signal. Is input to the video camera decoder 22 to decode the external light information of the video camera.

The external optical information input to the switch A / D converter 23 is converted from an analog signal to a digital signal. The digital signal converted by the switch A / D converter 23 is output as a control signal of the camera white balance controller 24. Camera white balance control unit 24
Then, the white balance shift of the camera 5 is controlled to be shifted in a certain direction. Therefore, unlike a normal camera white balance circuit, the operation is not performed so that all the color signals are balanced, that is, the R signal = G signal = B signal, and the white balance shift of the camera 5 is in a fixed direction. The shift is controlled so that the white balance shift of the camera 5 becomes clear. Also, for example, T
When the TL type automatic white balance circuit is adopted, the R control signal and the B control signal output from the camera white balance control unit 24 are used.

In the camera white balance control unit 24, the gain control is performed by the automatic gain control unit 20 based on the signal detected by the CCD 1b, and the yellow Y _e , the yellow cyan C _Y , and the green G corresponding to the gain are controlled. The R / B control signal of the camera 5 and the R / B control signal of the color EVF 6 are controlled based on the signal corresponding to each color. That is, the camera white balance control unit 24 raises the R control signal of the camera 5 and lowers the B control signal of the camera 5 when the color temperature is high and the intensity of the wavelength spectrum of the external light is high. The camera white balance control unit 24 lowers the R control signal of the camera 5 and raises the B control signal of the camera 5 when the color temperature is low and the intensity of the wavelength spectrum of the external light is weak. On the other hand, the camera white balance control unit 24 lowers the R control signal of the color EVF 6 and raises the B control signal of the color EVF 6 when the color temperature is high and the intensity of the wavelength spectrum of the external light is high. Further, the camera white balance control unit 24 raises the R control signal of the color EVF 6 and lowers the B control signal of the color EVF 6 when the color temperature is low and the intensity of the wavelength spectrum of the external light is weak. The camera white balance control unit 24 defines a control range for avoiding malfunction and extreme color change, and does not completely match the color temperature of the outside world, and the range of reddish white and bluish white. 4500K ~ 8500K (K is
Kelvin controls the white balance of the camera 5 within a range of color temperature). The camera white balance control unit 24 controls the white balance of the camera 5 so as to shift the white balance in a certain direction, thereby preventing the color shift of the nonlinear circuit such as the spectrum intensity regulating circuit 30.

The D / A converter 25 converts the control signal from the camera white balance controller 24 from digital to analog. In the camera RB adjustment unit 26, the R control signal and the B control signal converted from digital to analog by the D / A conversion unit 25 are input to the matrix / level controller 8 of the spectrum intensity regulating circuit 30 to implement the operation of FIG. The same brightness adjustment as in the example is performed and the liquid crystal display unit 19 is displayed in color. Therefore, in the embodiment shown in FIG. 3, it is possible to faithfully follow the change in the color temperature of the external light to enable the appropriate color reproduction, and to clearly recognize the deviation of the camera white balance and to obtain the white balance. By adjusting, it is possible to prevent discomfort due to the difference in color temperature change.

[0017]

As described above, according to the present invention, it is possible to faithfully follow the change in the color temperature of the external light and to appropriately reproduce the color. Further, according to the present invention, it is possible to achieve an excellent effect such that a sense of discomfort due to a difference in color temperature change can be prevented by clearly recognizing a shift in camera white balance and adjusting the white balance.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining an outline of an embodiment of an image pickup apparatus of the present invention.

FIG. 2 is a block diagram showing a specific configuration of an exemplary embodiment of the present invention.

FIG. 3 is a block diagram showing a specific configuration of another embodiment of the present invention.

[Simple explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spectral intensity detecting means 1a External light detecting section 1b CCD 2 Spectral intensity controlling means 3 Spectral intensity regulating means 4 Color viewfinder section 8 Matrix / level controller 9 Correction circuit 19 Liquid crystal display section 24 Camera white balance control section 30 Spectral intensity regulating circuit

Claims (3)

[Claims] 1. A spectrum intensity detecting means for detecting intensity of a wavelength spectrum of external light, and a spectrum intensity for controlling intensity of a wavelength spectrum of a color viewfinder in response to a spectrum intensity signal output from the spectrum intensity detecting means. An image pickup apparatus comprising: a control unit; and a spectrum intensity defining unit that defines the intensity of the wavelength spectrum of the color viewfinder based on a spectrum intensity control signal from the spectrum intensity controlling unit. 2. The image pickup device according to claim 1, wherein the spectral intensity detecting means has an external light detecting portion, and the spectral intensity controlling means is controlled according to a detection output from the external light detecting portion. apparatus. 3. The spectrum intensity detecting means has a solid-state image pickup section, the spectrum intensity control means has white balance control means, and the white balance of the color viewfinder is based on an image pickup signal from the solid-state image pickup section. 2. The image pickup apparatus according to claim 1, wherein the wavelength spectrum intensity of the color viewfinder is controlled based on a control signal from the white balance control means.