JPH06319151A - Imaging device - Google Patents

Abstract

PURPOSE:To easily attain image pickup in which color balance is unbalanced to a desired degree by amplifying each color signal of a color picture signal subjected to level adjustment individually with a color signal amplifier means whose signal amplification factor is optionally set. CONSTITUTION:Color picture signals obtained by a solid-state image pickup element 12 are provided as outputs of R, G, B signals independently and the level of the R, B signals is adjusted by relevant white balance amplifiers 15r, 15b respectively. When the operator uses a switch 20 to designate a desired color correction filter, a switch control signal to set a color signal amplification factor corresponding to the color correction filter is outputted from a pattern generating section 19. Then the R, G, B picture signals picked up by the solid- state image pickup element 12 are amplified and adjusted with an amplification factor corresponding to the transmission characteristic of a designated filter at operational amplifiers 17r, 17g, 17b respectively, and then the color picture signal whose color balance is unbalanced into a desired color state is obtd.

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 such as an electronic still camera having a solid-state image pickup device (CCD) for obtaining a color image signal.

[0002]

2. Description of the Related Art In general, a photographed image such as a photograph is required to have faithful color reproducibility, but on the other hand, a photograph may be intentionally photographed with an imbalanced color balance for the purpose of artistic effect. As described above, when shooting with an imbalance in color balance, an optical color correction filter is usually used, and by attaching this color correction filter to the front surface of the imaging lens, it is possible to obtain a photograph in which a desired color is emphasized. can get.

[0003]

However, in order to perform photographing with the color balance lost, it is necessary to attach and detach the color correction filter, which has a drawback that the photographing work becomes troublesome. The present invention has been made in view of the above problems, and provides an image pickup apparatus capable of easily performing image capturing with a desired color balance without the need to attach or remove a color correction filter. The purpose is to provide.

[0004]

That is, a first image pickup apparatus according to the present invention is an image pickup means for obtaining a color image signal and a white balance adjustment for adjusting the white balance of the color image signal obtained by this image pickup means. Means and
Color signal amplification means for individually amplifying each color signal in the color image signal whose white balance has been adjusted by the white balance adjustment means, and amplification factor setting means for arbitrarily setting the signal amplification factor of each of the individual color signal amplification means. And amplification factor varying means for changing the signal amplification factor of each color signal amplifying device according to the signal amplification factor for each color signal amplifying device set by this amplification factor setting device. It is a thing.

The second image pickup device according to the present invention is
The first image pickup apparatus further includes an input unit for inputting a signal amplification factor set in the amplification factor setting unit.

[0006]

That is, after the level of the color image signal output from the image pickup means is adjusted by the white balance adjusting means, each color signal of the level adjusted color image signal is set to an arbitrary signal amplification factor. Since each color signal is amplified individually by the color signal amplifying means, it is possible to perform photographing with a desired color balance.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing a configuration of an image pickup apparatus having a color signal correction function. In the figure, 11 is an image pickup optical system, and this image pickup optical system 11 is provided with an image pickup lens 11a and a diaphragm 11b. The optical image of the subject obtained through the image pickup optical system 11 is a solid-state image pickup device (color CC).
D) The image is incident on 12 and imaged. This solid-state image sensor 12 is
The solid-state image sensor 12 is provided with a large number of color pixels, each of which includes red (R), green (G), and blue (B), and stores charges according to each color wavelength of an incident optical image. The color image signals are independently output as R signal, G signal, and B signal.

On the other hand, 13 is a white balance sensor, 1
Reference numeral 4 denotes a white balance control unit. The white balance control unit 14 includes a white balance amplifier 15
r and 15b are connected. That is, the solid-state image sensor 1
The output signals R, G and B of 2 are white balance amplifiers 15r and 15 to which the R and B signals respectively correspond.
The level adjustment is performed by b, and the R, G, B signals after the white balance adjustment are individually output via the corresponding buffers 16r, 16g, 16b and the gain determining fixed resistors Rr1, Rg1, Rb1. Is input to operational amplifiers 17r, 17g, and 17b for amplifying the color signal.

The operational amplifiers 17r, 17g and 17b have three stages of variable gain switches 18r1 to 18r3, 18g1 to 18g3 and 18b1 arranged in parallel between their input and output terminals.
18b3 are variable gain resistors Rr21 to Rr23, Rg21 to Rg2.
3, Rb21 to Rb23, and variable gain switches 18r1 to 18r3, 18g1 to 18g3, 18b1 to 18 in the operational amplifiers 17r, 17g, and 17b.
The ON / OFF signal of b3 is supplied from the pattern generator 19.

The pattern generating section 19 includes a switch 20.
According to the designation of the color correction filter by the above-mentioned operational amplifiers 17r, 17g, by referring to the table data created in advance, the R, G, B level differences equivalent to those of the designated color correction filter can be obtained. Variable gain switch 18r1 to 18r3, 18g1 to 18g3, 18b1 to 18 in 17b
The b3 is ON / OFF controlled, that is, the pattern generation section 19 outputs an ON / OFF pattern switch control signal corresponding to the designated color correction filter.

FIG. 2 shows the spectral sensitivity characteristics (solid line) of each of R, G, and B of the solid-state image sensor 12 in the image pickup apparatus having the above-mentioned color signal correction function and the total spectral characteristic (broken line) of R, G, B combination. FIG.

In the figure, the sensitivity of red (R) having an incident light wavelength of 650 nm is "1", whereas the sensitivity of green (G) having an incident light wavelength of 530 nm is "0.7" and 450 nm. The sensitivity of blue (B) is "0.55". That is, in the solid-state imaging device 12, when an optical image corresponding to a subject is incident and image-formed, charges are accumulated according to the R, G, and B total spectral characteristics in FIG.
White balance adjustment is achieved via r and 15b.

FIG. 3 is a diagram showing the transmittance characteristics of the currently used blue correction filter with respect to the incident light wavelength. Figure 4
FIG. 3 is a diagram showing the transmittance characteristic of the currently used green correction filter with respect to the incident light wavelength.

FIG. 5 is a diagram showing the transmittance characteristic of the currently used yellow correction filter with respect to the incident light wavelength. That is, for example, the blue correction filter B1 in FIG. 3 has a high transmittance in the vicinity of the incident light wavelength of 360 nm to 560 nm, so that the spectral sensitivity characteristic in FIG. 2 corresponding to the transmission wavelength of the blue correction filter B1 occupies the ratio. Accordingly, for example, the amplification factor of the operational amplifier 17b that amplifies the blue (B) signal is set to a high level, the amplification factor of the operational amplifier 17g that amplifies the green (G) signal is set to an intermediate level, and the operational amplifier 17r that amplifies the red (R) signal is set. By setting the amplification factor of the above to approximately 0 level, it is possible to obtain the same color image signal as when the blue correction filter B1 is inserted.

That is, the color signal amplification factor of each of R, G, and B colors, which is proportional to the color ratio occupied by the spectral sensitivity characteristic corresponding to the transmission range of each color correction filter, is calculated for each operational amplifier 1.
7r, 17g, 17b variable gain switches 18r1-18
ON / O for r3, 18g1 to 18g3, 18b1 to 18b3
As the FF pattern, the pattern generating section 19 has the table data in advance.

As a result, when the operator designates a desired color correction filter with the switch 20, the switch control signal for setting the color signal amplification factor corresponding to the color correction filter is output from the pattern generating section 19.

Therefore, the R, G, and B color image signals picked up by the solid-state image pickup device 12 have respective amplification factors according to the transmission characteristics of the designated filters.
A color image signal is obtained which is amplified and adjusted by 7r, 17g, and 17b and whose color balance is broken into a desired color state.

Therefore, according to the image pickup apparatus having the color signal correction function having the above-described structure, it is possible to perform photographing with a desired color balance without mounting an actual color correction filter on the front surface of the image pickup lens. become.

[0019]

As described above, according to the present invention, after the level of the color image signal output from the image pickup means is adjusted by the white balance adjusting means, each color signal of the level adjusted color image signal is adjusted. However, since the signals are individually amplified by the color signal amplifying means in which the signal amplification factor is arbitrarily set, it is not necessary to attach or remove the color correction filter, and it is possible to easily perform image capturing in which the color balance is collapsed to a desired intensity. It is possible to provide an imaging device that enables the above.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration of an image pickup apparatus having a color signal correction function according to an embodiment of the image pickup apparatus of the present invention.

FIG. 2 is a diagram showing spectral sensitivity characteristics (solid lines) of R, G, and B of a solid-state imaging device in an imaging apparatus having the color signal correction function and a total spectral characteristic (broken line) of R, G, B combination.

FIG. 3 is a diagram showing a transmittance characteristic with respect to an incident light wavelength of a currently used blue correction filter.

FIG. 4 is a diagram showing the transmittance characteristic of the currently used green correction filter with respect to the incident light wavelength.

FIG. 5 is a diagram showing a transmittance characteristic of a currently used yellow correction filter with respect to an incident light wavelength.

[Explanation of symbols]

11 ... Imaging optical system, 11a ... Imaging lens, 11b ... Aperture, 12 ... Solid-state imaging device, 13 ... White balance sensor, 14 ... White balance control section, 15r, 15b ...
White balance amplifier, 16r, 16g, 16b ...
Buffer, 17r, 17g, 17b ... Operational amplifier, 18
r1 to 18r3, 18g1 to 18g3, 18b1 to 18b3 ... Gain variable switch, 19 ... Pattern generator, 20 ... Switch,
Rr1, Rg1, Rb1 ... Fixed resistors for gain determination, Rr21 to Rr2
3, Rg21 to Rg23, Rb21 to Rb23 ... Variable gain resistors.

Claims (2)

[Claims] 1. An image pickup device for obtaining a color image signal, a white balance adjustment device for adjusting the white balance of the color image signal obtained by the image pickup device, and a color image whose white balance is adjusted by the white balance adjustment device. Color signal amplification means for individually amplifying each color signal in the signal, amplification rate setting means for arbitrarily setting the signal amplification rate of each of the individual color signal amplification means, and individual colors set by this amplification rate setting means An image pickup apparatus comprising: an amplification factor changing unit that changes a signal amplification factor of each of the individual color signal amplification units according to a signal amplification factor of each of the signal amplification units. 2. The image pickup apparatus according to claim 1, further comprising an input unit for inputting a signal amplification factor set in each of the amplification factor setting units.