JPS604391A - Color temperature compensating device of color television camera - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

TECHNICAL FIELD The present invention relates to a color temperature compensation device for a color television camera, and the present invention relates to a color temperature compensation device for a color television camera. The challenge is to find a way to do this.

Prior Art (Figs. 1 to 6) Fig. 1 is a block diagram of a color temperature compensation circuit of a conventional color television camera, Fig. 2 is a configuration diagram of a color filter, and Fig. 3 is a block diagram of a color temperature compensation circuit of a conventional color television camera.
The figure is a block diagram of the color temperature compensation circuit of another conventional color television camera, Figure 4 is a spectral characteristic diagram based on color temperature KVC, Figure 5 is a spectral characteristic diagram of red and blue signals depending on color temperature, and Figure 6 is a spectral characteristic diagram of red and blue signals depending on color temperature.
The figure shows the amount of gain correction for red and 11' signals based on color temperature 1.

If the color temperature of the light illuminating the subject changes, the color temperature of the color television camera will change, and even if a white subject is photographed, it will not be photographed as white, so it is necessary to increase or lower the color temperature of the color television camera. It is necessary to adjust the rA, perform color temperature compensation, and maintain white balance.

This type of color temperature compensation circuit is shown in FIG. In the figure, a striped color filter 1 is arranged in front of an image pickup tube 2. This color filter 1, as shown in FIG.
The y-w filter I and the Yz -W filter ■ are completely crossed, and the cy-w filter I is in the same phase for each horizontal scan, and the YE
-W filter (2) is arranged so that its phase is inverted every horizontal scan. The output of the image pickup tube 2 is amplified by a preamplifier 3, and low-frequency F wave generators 4 and 5 separate the luminance signals YH and YL f.
, is added to the band F wave generator 6 which separates the color modulation signal. C
The red signal R and YE are modulated by the y-W filter I for each horizontal scan. The output signal from the band wave transducer 6 and the output signal from the one-time period delay line 7 are added to an adder 8 and a subtracter 9, respectively, and the
A red signal R and a betrayal month B are outputted from the device 8 and the subtractor 9, respectively. The output signal of Towara is detected by detectors 0 and 11, and a low frequency red signal R and blue signal B are output. Next, in order to match the gains of the red signal R and the blue signal B according to the color temperature of the low frequency signal for the color signal, variable gain amplifiers 12 and 13 are used to adjust the gain of the red signal R and the blue signal B.
” and adjust the color difference from subtractors 14 and 15 to +1R-YL
, B -YL fQte, together with the luminance signal YH 77 (:
R-encoder 16 plus a standard television signal.

This color television camera is comprised of temperature compensation circuit blocks 17 to 22. A white object is photographed before pointing a color television camera toward the object, and the color difference signals R-Yt, , B-YL output at this time are adjusted to be zero. Bll, the comparison circuits 17 and 18 generate the color difference signal R-Yt.
, and the standard price set so that B-YL is zero, and the output color difference signals R-YL and B-YL are compared. Switches 19 and 20 are closed while photographing a white object, and the signals obtained at this time are held in hold circuits 21 and 22.

This held signal is applied to external voltage control terminals of variable gain amplifiers 12 and 13 to control the gain. When switches 19 and 20 are closed, variable gain amplifiers 12 and 13 . Reduced by 9
Vessels 14 and 15. Comparison circuits 17 and 18. switch 19 and 2
0. The hold circuits 21 and 22 form a closed loop and act so that the color difference signals R-Yi, . . . B-YL become zero.

When the color difference signal becomes zero, switches 19 and 20 are opened, the voltage is held by bold circuits 21 and 22, and the color temperature K
seems to be changing.

This color television camera has the disadvantage that it cannot be used continuously because it is necessary to reset the color temperature every time the color temperature of illuminating the subject changes.

A color television camera that eliminates the above-mentioned drawbacks and is equipped with a color temperature compensation device that always fully automatically adjusts the color temperature has been known. The outline will be explained based on FIG. 3. Blocks with reference numerals 1 to 16 shown in the figure are the same as the blocks shown in FIG. 1, and therefore their explanation will be omitted.

31 and 32 are color detectors that detect different colors emitted by a light source, and 33 is a color temperature detector that obtains color temperature from the ratio of two different color signals detected by the color detector. 34 and 35
is a color temperature compensator that uses the fc multiplied signal output from the color temperature detector 33 to generate gain control voltages for the variable gain amplifiers 12 and 13 for red and blue signals.

As seen in the spectral characteristic diagram based on the color temperature VC shown in FIG. 4, the color temperature of illumination changes at each wavelength. Therefore, the values of the red signal and "#" applied to the detectors 10 and 11 change depending on the color temperature.

The reason for this is that, as shown in FIG. 5, the spectral characteristics of the red signal and the green signal change. The color temperature detector 33 is
Using the property that spectral characteristics change when the color temperature changes, the color temperature represented by the ratio of the values of two colors is detected. Therefore, the output ratio of variable orientation amplifiers 12 and 13 is:
As shown in Figure 5, from 3,200°K (3,00°
When it changes to 0'K, it will be about twice as long as IS Yoi Id, which takes about 2 minutes at a red light. Here, the gains of the variable gain amplifiers 12 and 13 at 4,500° are approximately 0.75° in order to make the color difference (, n/f: zero).
The 11T variable gain converter 13 for the green signal must be 15 times larger. Next, in order to make the color difference No. 4a zero at 6,000', the gain amplifier 12 of the red light is set to 15
The first gain amplifier 13'io for the green signal must be 75 times larger. Therefore, as shown in FIG. 6, the gains of the -iJ variable gain amplifiers 12 and 13 for red and blue signals must be changed depending on the color temperature. Color temperature compensators 34 and 35 generate control voltages for changing this gain. The color temperature compensators 34 and 35 compensate the color temperature by applying a control voltage to change the orientation to the red signal variable gain amplifier 12 and the blue signal 1d variable gain amplifier 13.

In a color television camera equipped with this conventional color temperature compensation device, in order to perform proper color temperature compensation, light having the same color temperature as the light illuminating the subject must be incident on the color detector. Under conditions that violate this assumption, it becomes difficult to perform appropriate color temperature compensation.

For example, if the subject is a person bathing in the light of the setting sun, the photographer turns his back to the setting sun, but the light that enters the color detector is from the blue sky whose color is almost unfaded. Since the color detector detects the color temperature of the blue sky when it is light, the output B/R of the color temperature detector (here, BV
(i evening signal, R is red signal) is a large one, and the gain of the blue signal variable gain amplifier is completely lowered 1. It acts to increase the gain of the red signal variable gain amplifier. Therefore, the blue video signal becomes weak, and color temperature compensation is performed by making the red video signal strong, so that the person being photographed appears abnormally reddish on a display device or the like. When photographing indoors and outdoors, there is a high possibility that light from inside the room will enter the color detector of the color television camera, rather than light from the object outdoors. Therefore, the color temperature detector outputs the color temperature of the indoor light, and does not compensate for the color temperature of the outdoor subject, but compensates for the indoor light, so the subject may appear unnatural. The reason for this is that the color detector tends to be displayed on a display device, etc. in a colored state.According to the conventional external sensor method, in which the color detector is placed on the body outside the camera lens system, the light detection area is the base angle, light having the same color temperature as the reflected light from the object will not be incident on the color detector, making it impossible to perform proper color temperature compensation.

Purpose of the Invention The present invention solves the drawbacks of conventional color temperature compensation devices for color television cameras. By detecting the color temperature of incident light from around the subject over a wide range and using the focal length setting value as a key element in evaluation when performing color temperature compensation, it is possible to perform more appropriate color temperature compensation. The overall objective is to provide a color part tk compensation device for a color television camera that can be used.

Structure of the Invention The present invention provides a first means for controlling at least two or more colors (orientation of No. 8) using a color information discrimination control signal, and a means for controlling at least two or more colors (orientation of No. a second means comprising a pair of detection means for detecting the color temperature of incident light from a plurality of regions; a third means for detecting a focal length setting value of the photographic lens; Color temperature compensation for a color television camera, comprising a fourth means for generating the control signal according to color A No. 8 so that the overall gain of the color signal is optimized using the signal detected by the third means. Features a device.

The scale can be applied to a (vI) type color television camera, and the number of aN pairs of color detectors for detecting color temperature can be increased or decreased as necessary,
The embodiments can be modified as appropriate within the scope of the claims set forth above.

DESCRIPTION OF EMBODIMENTS An embodiment of the color temperature compensating device for a color television camera according to the present invention will be described below with reference to FIGS. 7(a) to 7(e).

This will be explained in detail with reference to FIGS. 8(a) to (h) and FIGS. 9(a) to Ct).

An embodiment of the present invention will be described with reference to FIGS. 7(a) to 7(,).

In FIG. 7(a), 1 is a flower which is a subject, 2 is an imaging plane of an image pickup tube, a 36Fi photographing lens, and 31 and 32 are r-colored sand and a hanger. The color detectors 3J and 32 detect light of blue and red wavelengths, but may also detect light of other wavelengths. FIG. 7(b') shows the vicinity of the wandering photographic subject L, the photographing lens 36, and the photographic subject 1, and its back t!
Figure 7 (C) shows this oblique view from the image pickup tube f111.
.

In the figure, 37 is the image frame of the image pickup tube 2, and the color detectors 31 and 32 are arranged on the periphery behind and below the photographing lens 36. Therefore, outside ff1 (unlike the Sentsu force type), where the color detector is placed in the housing other than the lens thread of the conventional camera,
Since the light incident through the photographic lens 36 is reflected light from the subject itself, the color detectors 31 and 32 are not able to detect the color temperature of the reflected light itself from the subject; Since the color detectors 31 and 32 are placed on the same side at the rear, the light detection area is expanded and the color temperature of the surrounding light of the subject can also be detected. The light detection area is whistle 7
These are the hatched portion 38 in FIG. 7(a) and the portion 38 shown in FIG. 7(c).

As shown in FIG. 7(d), the reflected light of the subject and its surrounding light detected by the color detectors 31 and 32 are converted into electrical signals, which are added to the color temperature detector 33 to output a color temperature signal. do. This color temperature output signal is applied to color temperature compensators 34 and 35, and also to the variable gain amplifier 12 for the red signal and the variable gain amplifier 13 for the * signal to the gain frame section to perform proper color temperature compensation.

FIG. 7(e) shows an embodiment in which a color detector is applied to a zoom lens system.

In FIG. 7(e), 36 is a focusing lens;
40 is a variator lens, 41i convencator lens, 42 is a focal lens, and 43hv lens, and these lenses constitute a zoom lens thread. The focusing lens 36 has the function of adjusting the distance, the variator lens 40 has the function of changing the focal length, the compensator lens 41 has the function of correcting the movement of the image point caused by changing the magnification, and the focal lens 42 has the function of the relay lens 4.
3, and the relay lens 43 has a function of forming the final image that enters through the lens system on the imaging plane of the image pickup tube 2 with a predetermined size and brightness. 2
3 is an image pickup tube, and 31 and 32 are color detectors, which are arranged between the focusing lens 36 and the variator lens 40 and on the rear periphery of the focusing lens 36.

In such an arrangement, the focusing lens 36, which has a distance adjustment function, moves only a small amount when focusing, so even if the angle of view seen from the imaging plane changes when zooming. However, the light detection areas of the color detectors 31 and 32 when viewed through the focusing lens 36 do not change.

Similarly, in a zoom lens system, by arranging the color detectors 31 and 32 behind and around the photographing lens 36, it is possible to prevent light from passing through the focusing lens 36 (reflected light from the subject and !, J light transmission can be detected. Regarding the circuitry that performs color temperature compensation using the signals detected by the color detectors 31 and 32, as shown in FIG.
Since it is sufficient to use exactly the same thing as shown in d), the explanation thereof will be omitted.

Other embodiments of the present invention will be described below with reference to FIGS. 8(a) to 8(h). Give an example.

In FIGS. 8(a) and 8(b), ] U is the subject, L is the subject, 2 is an imaging tube, and 36 is a photographic lens.

31a and 32a, 31b and 32b, 31c and 32c, 3
1d and 32d are four pairs of color detectors, and a photographing lens 36
At the rear of the lens and at different angles of 90°,
Place it around the top, bottom, left and right of 6.

In FIG. 8(C), numeral 37 indicates the image frame of the imaging plane of the image pickup tube 2, and the color detectors 31a and 32a, 31b and 32b, 31c and 32c, 31d pass through the entire photographing lens 36.
The light detection area of 32d is the lowest part of the blade.

n (44a), upper area U (44b), left area L (
44c) and right region R (44d).

The subject and its surroundings are all covered by these four light detection areas. Therefore, the object and surrounding light in the photodetection area covering the entire object and its surroundings are detected by the four pairs of color detectors described above, and the output signals are sent to the evaluation calculation circuit shown in FIG. 45.

In FIG. 8(d), an example in which all four pairs of color detectors are arranged in a zoom lens system will be explained. Focusing lens 36. Variator lens 40. Convencator lens 41, 7 Ocal lens 42. The relay lens 430 function has already been explained in FIG. 7(6), so its explanation will be omitted. Behind the focusing lens 36 and at different angles of 900 degrees, the focusing lens 360 periphery VC, 4 pairs of color detectors 31 are located above, below, and to the left and right.
a and 32a, 31b and 32b, 31c and 32c.

31d and 32d are arranged.

In FIG. 8(e), four pairs of color detectors 31a and 32a
, 31b and 32b, 31c and 32c.

Output signals No. 1 from 31d and 32d are input to the switching circuit 46 of the plan determination circuit 45, converted into digital signals by the AD converter 47, and input to the CPU 48. is converted into an analog quantity by the DA converter 49, and the color temperature compensator 34
is output to 35. This output signal is applied to the red signal variable gain amplifier 12 and the blue signal variable gain amplifier 13 in FIG. 7(d) to perform appropriate color temperature compensation.

In FIG. 8(h), the color temperature value D in the lower area, upper area U, left area, and right area R.
A flowchart of evaluation determination in which c, Uc, Lc, and Re are detected by four pairs of color detectors to obtain a color temperature compensation signal will be described.

In this evaluation (i judgment flow diagram), if the power is on as shown, the color temperature signal Da from the four pairs of color detectors is
, Uc, Lc, and Re are input, two of these color temperature detection signals are compared sequentially, and the output signal X of the comparison result (a total of 12 comparison results can be obtained) is subjected to color temperature compensation. Add it to the container.

The principle of evaluation judgment based on the output signal In this case, the output signal
c.

Referring again to FIGS. 8(f) to 8(h), the color temperature output signals Uc from the four pairs of color detectors.

Input Dc, Lc, Rc f, first Uc and DC
Compare whether they are approximately equal or not, and if YES, then compare whether KUc and Lc are approximately equal or not, and select YES.
If so, compare whether Uc and Re are equal to I or not, and if YES (ffll, Uc z Da
z Lc z Re), the output signal X is X −Uc
+Dc +La +Re/4. If the comparison result of Uc and Lc is No, first compare whether Uc and Re are almost the same, and if YES (that is, Uc
'< Da, Uc, i' Lc, Uck
Re ) Output signal X is X = Uc + Da + Re
/ 3, but if the comparison result between Uc and Re is No (that is, Uc '' Dc, Uc$: Lc,
Uc $ Re ), the output signal X is X = Uc
+Da/2. Also, the comparison result between Uc and Re is N
o (i.e., Uc z Dc , Uc z
Lc, Uc, %Re), the output signal X is
= Uc +Dc +Lc/3.

Compare whether Uc and DC are almost equal or not.

(i.e., Uc〆Da), then Uc and Lc
Compare whether they are almost equal or not, and if YES, then compare whether Uc and Re are equal or not, and if YES (that is, Uc % Dc, Uc k L
c.

Lc z Re ), the output signal X is X = Uc +L
c 10Re/3. The comparison result of Uc and Re is N
If O (i.e., Uc $ Dc , Uc〆L
c), then compare whether Uc and Rc are approximately equal,
If YES (i.e., Uc %' Dc , U
c% Lc, UckRe), output signal X
Let X = Uc + Re / 2. If the comparison result between Uc and Re is No (that is, Uc〆Dc).

Uc k Lc , Uc %' Re ), and the output signal X FiX = Uc + LC/2.

Next, compare DC and Lc to see if they are almost equal.
If S (i.e., TJc %' Da , U
c%' Lc.

Uc %' Re , Dca-t Lc ), then compare whether Dc and Re are approximately equal or not, and if YES (that is, Uc %' Da , Uc %' L
c , Uc $ Re , Da ~ Lc , Da
z Re ), the output signal X is X = Dc + Lc
10Re/3. Compare whether Dc and Lc are approximately equal or not, and if ygs (i.e., Uc %'
Dc, Uc%' Lc.

Uc @ Re, Dcz Lc), then compare whether DC and Re are approximately equal or not, and if YES (i.e., Uc%' DC, Uc%Lc, Uc%'
Rc, Dc%Lc, ]”%zl◇, output signal X
Let X = Dc + Re / 2. If the comparison result between Dc and Rc is NO (that is, Uc〆Da.

Uc%Lc, Uc$Re, Dc~L(
! , DC% Re ), the output signal X is X = Da
+Lc/2.

Lc (!: Compare whether Re is almost to blame or not.YE
If S, then ζ or 4 (i.e., Uc f−Da, Uc
%' Le , Uc$ Re , Dc % Lc
, Dc%'Re, LcQ=Bc),
The output signal X is assumed to be X = Lc + Re / 2. If the comparison result between Lc and Re is No (that is, DczDc).

Uc$Lc, DczRe, Dc〆Lc,
Dc S Rc, Lc〆Rc), output signal X is
=Uc.

In this embodiment of the present invention, the light detection area is expanded by arranging four pairs of color detectors around the rear of the photographic lens. , it is possible to detect objects with high saturation without being influenced by them, and to perform appropriate color temperature compensation.

Note that the present invention can detect the color temperature of the subject and/or incident light from the periphery of the subject by placing a color detector in or behind the photographic lens. As described above, by arranging the color detector around the rear of the photographic lens, more appropriate color temperature can be detected.

9(a) to (f), several further embodiments of the present invention are illustrated.

In Figure 9 (a), behind the focusing lens 36 of the zoom lens system, four pairs of color detectors 31a and 32a are installed at different angles of 90 degrees and around the lens a6.
, 31b and 32b, 31c and 32c, and 31d and 32d are arranged. Further V' i A work other than the lens system of a color television camera 6 ("C1 pair of color detectors 36a and 3
6b, which is used as an external detector to detect the entire color temperature of the light incident through the lens system. As mentioned above, color temperature information and illuminance information can be obtained from the outputs of the four pairs of color detectors, and this will be explained with reference to FIG. 9(b). The signals detected in are input to the adder circuit S and the divider circuit, respectively. In the adder circuit S, the detection signals from the color detectors 31a and 32a are added to obtain illuminance information, and in the divider circuit, Color temperature information can be obtained from the ratio of the detection signals from the color detectors 31a and 32a.In addition, the color temperature information (only the A report is obtained) is not obtained from the outside readings 36a and 36b. Therefore, four sets of illuminance information and four sets of color temperature + are obtained from the outputs of the four pairs of color detectors mentioned above.Referring to FIG. 9(a) again, focusing lens 36 In this method, a subject located near infinity is focused, and distance information when the subject is focused is generated from a distance information generator 48.

When photographing on the wide side (short focal length) or the telephoto side (long focal length), focal length information is generated from the focal length information generator 49 by fully adjusting the variator lens 40 and convencator lens 41. . Output signals from the four pairs of color detectors described above and the external detector,
The distance information from the distance information generator 48 and the focal length information from the focal length information generator 49 are input to the evaluation determination circuit 45. Historically, in color television cameras,
Strobe information when shooting in strobe mode S, manual information when shooting in manual mode M by setting the color temperature setting knob on the color television camera housing, and manual information when shooting in manual mode M. The ff information indicating whether to shoot in strobe mode S, manual mode M, or composite mode C, which will be explained later, is input to the evaluation judgment circuit 45.

The above-mentioned information 7 of the spirits is inputted to the evaluation judgment circuit 4.
5 is shown in the block diagram R, Port 9+t, C).

In the same figure, R and B are red and blue filters, 31
b and 32b are color detectors that detect the color temperature of light in the upper region U of the valley 1' field of view, and 31d and 32d are the right region R of the field of view.
Color detectors 31c and 32c detect the color temperature of the light in the left area of the object;
Color detectors 1a and 328 detect the color temperature of light in the lower region of the object. 36a and 3f+b are provided in the housing of the color television camera other than the lens system, and the external device that detects the color temperature of the light incident through the lens system is a detector; The outputs from the detector and four pairs of color detectors are input to a switching circuit 41 via a preamplifier. Furthermore, distance information from the distance signal generator 48, focal length information from the focal length signal generator 49, strobe mode information S, manual mode information M, and mode selection information M/S obtained by the mode changeover switch. /C is input to the switching circuit 41. The above-mentioned information sequentially detected by the switching circuit 41 is converted into a digital quantity via the AD converter 42, inputted to the arithmetic circuit 43, where judgment and evaluation described later is performed, and the obtained signal is sent to the DA converter 44. is converted into an analog quantity and output as a color temperature compensation signal.

FIG. 9(d) shows an arithmetic circuit 43 to which the various information described above is input. The information input to the arithmetic circuit 43 will be explained below. xI is the output value k of the external detector G, X! is the output value of the color detector in the upper region U, and
a is the output value of the color detector in the left area, and X4 is the output value of the color detector in the right area.

is the output value of the color detector in the lower region. A is the distance information generated from the distance information generator 48, the output value of which is indicated by t, and is set to 0 when the object is located close to the object, and 1 when the object is located at the infinity 6 position. The distance value to the subject is expressed by compressing it into a value from 0 to l. F is focal length information generated from the focal length information generator 49, and its output value is indicated by f, which is set to 0 for wide and l for tele, = value of focal length between them. is expressed by compressing it into a value between 0 and 1. B
is the illuminance information obtained by adding the outputs from four pairs of color detectors, where the illuminance value of the upper region U is Lu, the illuminance value of the left region is LL, and the illuminance value of the right region R is The illuminance value of LR and the lower region is indicated by LD.

The M/S/C mode information that is input after switching to manual mode M, strobe mode S, or composite mode C is indicated by W, and in the case of manual mode M, it is indicated by W.
=00, W2O3 for strobe mode S, and W=IO for composite mode C. KIf: Color temperature information manually selected and set using the color temperature setting dial provided on the housing of the color television camera.
The value is denoted by K.

FIG. 9(e) shows a flowchart for obtaining the chromaticity compensation signal by inputting the various axis information described above.

In the figure, when the power is on, the various pieces of information described above are sequentially read through the switches in the arithmetic circuit. The embedded M/S/C mode information W is W=OO
That is, it is determined whether or not manual mode M is set. If YES, operation X of manual mode M, which will be described later, is performed. Next, it is determined whether W is W=01, that is, strobe mode S or not, and 1/i is determined. If YES, the calculation for strobe mode S, which will be described later, is performed. W2O3 determination is No
In this case, since W is naturally W=10 and the composite mode is C, the computation of the composite mode C, which will be described later, is performed.

The performance circuit shown in FIG. 9(e) is configured to perform calculations based on the following equations.

The arithmetic expression is X==aXxXE, and how this expression is used to determine the color temperature compensation signal in each mode by the arithmetic circuit will be described below.

In addition, X indicates a color temperature compensation signal, and positive indicates all values that statistically consider the outputs of the outer/Normal detector G and 4 pairs of color detectors, or manual mode M and distance information. , the vector product of focal length information p, strobe mode i, and illuminance information 100, where 100 indicates instantaneous values of external detector G and four pairs of color detectors in a vector view. Note that vector proofs will be displayed with a symbol above the characters.

Now, the previous a is a= (1-f, , I-?, , 1-f?B,
l −9,.

ly, ).

Also, X is Represented by X=MXAXFXSXB.

The color temperature compensation signal X in this embodiment is expressed as: X = a, xl + at Xfi + as Xs
+ a4X4 + as
'-as 'eBy varying it according to various parameters, we finally obtain a color temperature compensation signal, which is then mapped to equation (1).
When expressed using the IJ equation, it becomes.

Here, b ” Chl r bl r h, r h4
r b51), it can be expressed as x = h x b (3).

Now, the external components are detector G and four pairs of color detectors U and L.

Since the output values of R and D, distance information be able to.

Here, a, A, F, and B are the outputs of each color detector, respectively.
This is a coefficient vector formed according to subject distance, focal length, and illuminance. In addition, the coefficient vector 100 for the strobe mode and the coefficient vector M for the manual mode are also vector-multiplied.

Therefore, h is: h = a X A X F X B X S X M
(4) becomes.

In equation (4), ! -Symptom XA

y I/ represents the abnormality W'f for each output of the color detector.

The larger the level difference between the output value Xl of the color detector and the output values of other color detectors, the closer it approaches 1, and becomes 0 if there is no level difference between the two.

Therefore, for all values of the output value xj of the color detector except the output value xl of the color detector
)" and add this value 21' is 0 (N-1)
It represents the degree of abnormality of the output value xI of the color detector between.

Therefore, it indicates the degree of abnormality of the output value XI of the color detector within the song. Therefore,
The above i vector is a= (1-rl, ty, 1-t, 1-
y,, 5-y6), the coefficient of the output value xi of the color detector with a high degree of abnormality should approach 0. Conversely, the external color detector G and 4 pairs of color detectors should be Output values X1 to X,
are equal, then i is greater than a = [1, t, 1, 1 . x].

In this way, the external Ventre i compares the output value levels of the detector G and the four pairs of color detectors, and reduces the weight of the output value level of the abnormal detector based on the principle of majority voting. It is a vector.

Next, depending on the value of distance information If the distance is infinite, it is indicated by t = 1, so by substituting this, this means that the closer the distance to the subject, the more the external detector G and the color detector in the upper area U. This means that as the distance to the subject increases to infinity, the weight of the output values of the color detectors in the left region R and right region R increases.

X is a vector for weighting according to the distance to the subject in this way.

Next, when the output value of the focal length information R is from the wide side to the telephoto side according to the value ゛f, when it is on the wide side, as mentioned above, f = 0, so by substituting this, when it is on the telephoto side, Since f=1, by substituting this, this means that the closer the focal length information R is to the wide side, the
In the evening), emphasis should be placed on the output of the detector G and the color detector in the upper area U.Also, the closer you get to the telephoto side, the closer the output of the external detector G will be to O, area I7 and right area R
This means that the weights of the four pairs of color detector outputs of the upper region U and the lower region U are uniformly averaged.

In this way, the focal length information V is expressed as a 9/C vector, which is a stop change according to the focal length.

Next, the output values of illumination information B Lu, LL, LR, L
From D, the formula showing the brightness ratio of the upper region U is expressed as follows: When the illuminance value Lu of the upper region U becomes large, the outer advantage is the color detection of the detector G, the left region R, and the right region R. When the illuminance value Lu is at an intermediate level, emphasis is placed on the output value of the color detector in the left area and right area R, and when the illuminance value Lu is small, the output value of the color detector in the upper area U and the left area is emphasized. This vector is used to weight the output values of the color detectors in the lower area, the right area, and the lower area, and is used to weight the area according to the heat from the object field.

Next, manual mode M, strobe mode S.

The calculation process for calculating the color temperature compensation signal X in composite mode C will be explained.

Regarding calculations in manual mode M.

Let k be the value set on the color temperature setting dial provided on the casing of the color television camera. and,
The formula for calculating the color temperature compensation signal is based on the above formula (3),
It is represented by X = a X X X b. Here, X is expressed as X=MXAXFXSXB, so by substituting it into the above equation (3),
B X b. Since the manually set color temperature value is k, if a diagonal matrix of manual mode M is formed, then an i vector and a hundred vector are formed as follows. Next, distance @x, focal length information p
, strobe information ", A complete matrix of illuminance information i is formed, and matrix multiplication of M, a, b, A, F, S, B is performed to obtain X=k, which is output as a golden temperature compensation signal.

Regarding the calculation in strobe mode S, as in the case of manual mode M, X=aXMXAX
To perform vector multiplication of FXSXBXb, use the value C set in the strobe mode to form a diagonal matrix for the strobe modes. Next, the i vector and the 100 vector are formed as follows. Distance J1ftt1 is reported X, focal length information Y.

Manual 7-card information M, illuminance information 100 matrix) IJ matrix is multiplied by B to obtain X=C, which is output as a color temperature signal.

Regarding calculations in board mode C Using distance value t of distance information A, form a diagonal matrix of

Also, a diagonal matrix is formed using the focal length information F(7) focal length f.

Therefore, the value of illuminance information B Lυe LL + LR, LD
, form a diagonal matrix from this value of j.

Strobe mode S and manual mode)' M Told
Since it is not used, form a diagonal matrix of . And X=aXMXA
XFXSXBXb's Mar-IJ-X5JF'31f line;'j, and outputs a color temperature compensation signal.

In addition, in composite mode C, the focal length value f of the focal length information F is input to the wave power 1 circuit, and the distance ML information @A and the illuminance (i
1/To explain the calculation process for obtaining the color temperature compensation signal
Using the focal length value f of , form a diagonal matrix of .

Next, since distance information A, illuminance information B, manual mode information M, and strobe mode information @S are unused information, a diagonal matrix is formed.

-t, X = a
S X B X b (b Performs matrix multiplication and outputs chromaticity compensation signal X.

In this way, manual 7-mode M, strobe mode S
The output X obtained for the and composite mode C is a color temperature compensation signal, but the output
It is used after the gain of the amplification control system is adjusted and the offset is monitored to keep it within a certain range.

In Fig. 9(f), excluding the external detector G, there are four pairs of color detectors, distance information A, focal length + information F, illuminance value Lu obtained from the color detectors in the Hijikata area U, etc. Fig. 10 shows a flowchart of another embodiment for calculating a color temperature compensation signal using the following parameters and other parameters.

If it is determined in step (2) that the power is on, input information is read by scanning the switch in step (2). If it is determined in step (2) that the mode is manual mode M, the color temperature setting value of the color temperature setting dial provided on the casing of the color television camera is output in step (2). If it is determined that the mode is not manual mode M, it is determined in step (2) whether or not the strobe mode is S. If the mode is strobe mode S, the color temperature value of the strobe to be used is output in step (2). In the step, it is determined whether the illuminance value Lu of the upper region obtained by adding the outputs from the pair of color detectors of the upper region U is larger than a preset value LM, and If , the outputs Lc and Re of the color detectors of the left region R and the right region
Emphasis is placed on the output of X = Lc + Re/2 f. Lu) When the LM is not present, the distance to the subject is known in step ①, and when it is determined that the distance t is larger than the preset distance AM, the color detectors of the left area R and the right area R are detected. Output (X = Lc + Re / 2 with emphasis on + - is output. After that, in step 2, it is determined whether the distance t to the subject is smaller than the preset distance Am, and txtm
At ζ, emphasis is placed on the appearance of the color detector in the upper region U, and in step (2), X = Uc is output.

Note that the above-mentioned preset values tM and Am are large/
The relationship between the two is tM〉.

t (If not Am, in step 0, it is determined whether the value f of the focal length information F is larger than a preset value fM, and if f>fM, step [
The average value of the outputs of the four pairs of color detectors in phase] X = D
Output a +Uc +Lc +Re/4 f. f
> If not fM, it is determined in step [phase] whether the focal length value fm is smaller than the preset focal length value, and f (if fm, the output f of the color detector in the upper region U If it is not ! It is determined, and if the baldness is equal, outputs X = Dc + Uc + Lc + Re / 4. If they are not almost equal, vC1, that is, step ■
In the case where the output values of the color detectors in the upper region U, right region R1, left region, and lower region are mutually acceptable, the output of the color detector in the upper region U is f X =
output as Uc, otherwise the average value of the outputs of the four pairs of color detectors, X = Da + Uc + Lc +
Outputs Re/4.

After the value of X to be output as the color temperature compensation signal is calculated in this way, the process returns to step 1 again and this loop is repeated.

The flowchart shows a case where a color temperature compensation signal is calculated using only the focal length information F and other parameters among the distance information A, the focal length information F, and the illuminance value Lu obtained from the color detector in the upper region U. will be explained with reference to FIG. 9(2).

If it is determined in step ■ that the power is on,
In step (3), the human power information '#i' is read by scanning the switch. If it is determined in step (2) that the mode is manual mode M, the color temperature value of the color temperature setting dial provided on the casing of the color television camera is output in step (2). If it is determined that the manual mode is not M, it is determined in step (2) whether or not the strobe mode S is in effect, and if it is in the strobe mode S, the color temperature value of the strobe to be used is output in step (2). In step ■, it is determined whether the focal length value f is larger than a preset value fM.
> fM, in step ■, the average value of the outputs of the four pairs of color detectors X = Da + Uc -1-L
Outputs c + Re/4. If f>fM, it is determined in step (2) whether the focal length value f is smaller than a preset value fm, and f(f
In the case of m, in step [phase], the output of the color detector in the upper region U is output as f X = Uc. f (f
If not, in step 2, it is determined whether the output values of the color detectors in the upper region U, right region R2, left region R, and lower region are almost equal, and if they are approximately equal, in step X=Da 10 Uc + Lc + Re /
Outputs 4. If 1 yen is not equal, then in step 0, if it is determined that the output values of the color detectors in the upper area U, right area R2, left area, and lower area are not equal, step [ ] in the upper region U
Emphasis is placed on the output of the color detector and outputs X = Uc, and if it is determined otherwise, X =
Dc + Uc + Lc -) - Re / 4 is output.

After the value of X to be output as the color temperature compensation signal is calculated in this way, the process returns to step 1 again and this loop is repeated.

In addition, when shooting in automatic tracking mode by continuously and automatically adjusting the white balance, it is necessary to detect the color temperature of the light illuminating the subject and quickly and accurately control the color temperature. . Therefore, depending on the usage conditions of the color television camera and the subject to be photographed, in addition to the values detected by the multiple pairs of color detectors, the distance setting value, focal length setting value, illuminance value, and external values may also be detected by the detector. The weighting of parameter values such as color temperature is completely appropriate and it is necessary to set evaluation criteria.

- In addition, in a simple color television camera with a small number of control parameters, it is necessary to set evaluation criteria by weighting according to the most frequently used state when photographing a subject.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, by arranging a plurality of pairs of color detectors in or out of the photographing lens of a color television camera, it is possible to detect light incident from an object and/or a forgiving region around the object. It is now possible to detect the color temperature of light, and it is possible to perform appropriate color temperature compensation without being affected by objects with low saturation, and the focal length setting value can be used as an evaluation judgment factor when performing color temperature compensation. By adding VC, more appropriate color temperature compensation can be performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a color temperature corrector of a conventional color television camera, FIG. 2 is a block diagram of a color filter, and FIG. 3 is a block diagram of a color temperature corrector of another conventional color television camera. Figure 4 is a fractional energy distribution curve diagram, Figure 5 is a spectral characteristic diagram of red and blue signals based on color temperature signals, and Figure 6 is a diagram of spectral characteristics of red and blue signals based on color temperature signals.
The figure shows the gain correction sound of red and blue signals depending on the color temperature. FIG. 7(b) is a side sectional view of the main parts of the color television camera, FIG. 7(b) is an additional perspective view of the object shown in FIG. 7(a), and FIG. 7(d) is a block diagram of the color temperature compensation circuit, FIG. 7(e) is a cross-sectional view of a zoom lens system in which a color detector is arranged, and FIG.
FIGS. 8(a) to 8(f) explain other embodiments of the present invention, and FIG. 8(a) is a side sectional view of a subject and main parts of a color television camera. Figure 8(b) is a perspective view of what is shown in Figure 8(a), Figure 8(e) is a view of the subject and its surroundings viewed from the image pickup tube side, and Figure 8(d) is a zoom lens system. FIG. 8(e) is a block diagram of a color temperature signal detection circuit including an evaluation judgment circuit, and FIG. 8(f) to FIG. 8(h) are
9(a) shows an evaluation judgment flowchart for obtaining color temperature compensation (I), and FIGS. 9(a) to 9(f) show still another embodiment of the present invention. ) is a side view of an embodiment in which four pairs of color detectors are arranged in a zoom lens system, and FIG.
) is a one-way block diagram that calculates color temperature and illuminance from the output from a color detector, Figure 9 (C) is a circuit block diagram of the embodiment shown in @ Figure 9 (a), and Figure 9 (d ) is a circuit diagram where various parameters are input, FIG. 9(e) is a flow diagram showing calculations in manual mode M, strobe mode S, and composite mode C, and FIG. 9(f) is a color diagram using another method. FIG. 9(y) is a flowchart for outputting a temperature compensation signal. FIG. 9(y) shows a flowchart when the focal length setting value is used as a parameter. Figure 9(c)
In, 31a and 31b. 31b and 32b, 31e, 32c, 31d and 32d are 4
A pair of color detectors, 36a and 36b are external color detectors, 41 is a switching circuit, 42 is an AD conversion circuit 43
Fi calculation circuit, 44 DA conversion circuit, 45 evaluation judgment circuit, 48 distance signal generator, 49 focal length signal generator, S strobe mode, M manual mode, M/
Shows the S/C & mode changeover switch. Special it'' [Applicant Canon Co., Ltd. tψ Sat vlθθ λri π■ : Skin length 1zνρ 4j
Sand ρ ni〃θ (-(n color 5 fake n 8th fuguri 89 figure (e)

Claims (3)

[Claims] (1) A first means for controlling with at least two or more color signal control signals; a second means consisting of a plurality of pairs of detection means for totally detecting the color temperature of the incident light from the region; a third means for detecting the entire focal length setting value of the photographing lens; Color temperature compensation for a color television camera, comprising a fourth means for generating the control signal for each color code so that the gain of the color signal is optimized using the signal detected by the means. Device. (2) A second method i consisting of the plurality of pairs of detection means described above
2. The color temperature compensation device for a color television camera according to claim 1, wherein the color temperature compensation device is disposed in or behind a photographing lens of a zoom lens system. (3) The 20th means consisting of the plurality of pairs of detecting means described above consists of only four pairs of detecting means. ψcompensation device.