JP3258655B2 - Video camera equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A Industrial application field B Outline of the invention C Conventional technology (FIGS. 12 and 13) D Problems to be solved by the invention (FIGS. 12 and 13) E Means for solving the problems F function G embodiment (G1) First embodiment (FIG. 1) (G2) Second embodiment (FIG. 2) (G3) Third embodiment (FIG. 3) (G4) Fourth embodiment (FIG. (Fig. 4) (G5) Fifth Embodiment (Fig. 5) (G6) Sixth Embodiment (Fig. 6) (G7) Specific Configuration of Lens Identification Unit Effect of Invention A Industrial Application Field The present invention is a video The present invention relates to a camera device, particularly to an automatic white balance adjustment circuit of a video camera using an interchangeable lens.

B. Outline of the Invention When a plurality of types of interchangeable lens units are attached to the video camera body, when the interchangeable lens units are attached, the white balance correction data memory means provided in the interchangeable lens unit is read from the video camera body side. The white balance correction data is read by giving a clock signal.

C Conventional technology Conventionally, in this type of video camera system,
Next, as shown in FIG. 12, the photographing lens system 2 and the image pickup device 1
In a state where a white subject is imaged by an image pickup system including a CCD (charge coupled device), an amplifier circuit 3 and a signal processing circuit 4 to obtain a color signal, a white balance error included in the color signal is obtained. Is corrected by a white balance adjustment circuit 7 (hereinafter referred to as a closed loop type white balance adjustment circuit) constituting a feedback loop.

In the video camera system 10 having a white balance adjusting circuit 7 of the closed-loop through the amplifier circuit 3 converts the incident light LA1 image pickup device 1 is received via the imaging lens system 2 to the video signal S _V signal It is given to the processing circuit 4.
The signal processing circuit 4 converts the video signal _SV into a red signal S _R and a green signal S _G
And after separating the blue signal S _B, which respectively amplifying circuit
The output color signals S _RO , S _GO , and S _BO are sent to the matrix circuit 6 via 5A, 5B, and 5C.

The matrix circuit 6 converts the output color signals S _RO , S _GO , and S _BO into a luminance signal S _Y and color difference signals S _RY , S _BY and sends them to a recording system (not shown).

Here, the white balance adjustment circuit 7 outputs the output color signal S _RO
And _{SGO received} by the operational amplifier circuit 7A to obtain a red correction signal _SCR , which is supplied to the amplifier circuit 5A via the internal memory M1.
As a gain control signal, the output color signals S _GO and S _BO are received by the operational amplifier circuit 7B to obtain a blue correction signal S _CB , and this is supplied to the amplifier circuit 5C via the internal memory M2 as a gain control signal, thus it is adapted to fed back control red signal S _R and the output color signal based on the blue signal S _B S _RO and S _BO.

In the video camera system 10 having the closed-loop white balance adjusting circuit 7 shown in FIG. 12, the photographer performs signal processing by photographing a white subject such as a so-called white lens cap or white paper with the photographing lens system 2. amplifying circuit 5A, 5B, obtained from 5C output color signals S _RO, is an error in the white balance of the S _GO and S _BO is based red signal S _R obtained from the circuit 4, a green signal S _G and blue signal S _B time, the white balance adjusting circuit 7 and stored in the internal memory M1 and M2 to form the red correction signal S _CR and a blue correction signal S _CB to cancel the error, stored in the internal memory M1 and M2 red and it is made to be able to control the gain of the amplifying circuit 5A and 5C read out as required blue correction signal S _CR and S _CB.

Thus pre After the white balance adjustment, when a photographer to take any subject, the white balance adjusting circuit 7 using the red and blue correction signal S _CR and S _CB stored in the internal memories M1 and M2 Red and blue signals S _R
And by correcting the S _B, the output color signal S _RO with a good white balance, S _GO, causes S _BO.

In addition, as a conventional video camera system,
As shown in the figure, a correction signal forming circuit including the external sensor 11 and the gain control circuit unit 12 is provided separately from the imaging system,
The white diffusing plate 14 to form a correction signal S _TR and S _TB based on TsuTsuta white light, so as to correct the white balance error of the correction signal S _TR and color signals obtained from the O connexion imaging system S _TB In some cases, a white balance adjustment circuit 13 (hereinafter referred to as an open-loop type white balance adjustment circuit) is provided.

In the conventional video camera system 20 of FIG. 13 having the open-loop white balance adjustment circuit 13,
A white balance adjustment system is formed by a white diffusion plate 14 and a white balance adjustment circuit 13 with respect to an imaging system including the imaging lens system 2, the image sensor 1, the amplifier circuit 3, and the signal processing circuit 4.

The white balance adjustment circuit 13 receives white light diffused through a white diffusion plate 14 provided separately from the video camera to the red component sensor 11R, the green component sensor 11G, and the blue component sensor 11B to detect red. Signal S _WR , green detection signal S _WG and blue detection signal S _WB are converted to gain control circuit section
Give to 12.

The gain control circuit unit 12 includes operational amplifiers 15A and 15B, respectively.
And first and second gain control circuits 12A and 12B having an inverting amplifier circuit configuration including resistors R1 and R2. The first gain control circuit 12A is input to an inverting input terminal of an operational amplifier 15A. It is adapted to gain control of the red detection signal S _WR and non-inverting becomes a difference signal between the green detection signal S _WG inputted to the input terminal red correction signal S _TR amplifying circuit 5A to obtain the.

Similarly, the second gain control circuit 12B includes an operational amplifier 15B
Inverting the blue detection signal S _WB which is input to the input terminal, to gain control of the amplifier circuit 5C to obtain a blue correction signal S _TB made a difference signal between the non-inverting input to the input end green detected signal S _WG of Has been made.

With this configuration, in the white balance adjustment circuit 13 separately provided for the imaging system, the red correction signal _STR and the blue correction signal _STB are obtained based on the white diffusion plate 14, for example, The white balance can always be adjusted in response to a change in shooting conditions such as a change in illumination, and the photographer does not need to perform a complicated white balance adjustment operation before shooting. 4, 646, 161; Japanese Utility Model Application Laid-Open No. 61-1982).

D Problems to be Solved by the Invention However, in the video camera system 20 having the open-loop type white balance adjustment circuit 13 shown in FIG. 13, since the white light is received by the external sensor, the photographing is performed. When the lens system 2 is replaced with a lens, even if an error occurs in the white balance of a captured image due to a change in the spectral characteristics of the lens, this cannot be corrected.

For example, in a lens-interchangeable video camera system, by by connexion spectral characteristics to the lens to be used is different, the red and blue correction signal S _TR and S _TB obtained in the white balance adjustment circuit 13, through the actual lens obtained to the extent practical suitability white balance error of the video signal S _V it is may not give correct.

In the video camera system 10 having the closed-loop white balance adjustment circuit 7 shown in FIG. 12, when an interchangeable lens having a spectral characteristic exceeding the control range of the white balance adjustment circuit 7 is used, an appropriate white balance adjustment circuit is used. There was a problem that the balance could not be adjusted.

The present invention has been made in view of the above points, and aims to propose a video camera system that can always perform appropriate white balance adjustment even when using interchangeable lenses having different spectral characteristics. .

Means for Solving E Problem In order to solve such a problem, in the present invention, an interchangeable lens unit 28 for receiving incident light, a video camera body 27,
Signal processing means (1, 3, 4) provided on the video camera main body 27 and transmitting a video signal in response to incident light incident from the interchangeable lens section 28, and signals from the signal processing means (1, 3, 4) In a video camera device having a white balance adjusting means 13 for adjusting a white balance based on the above, a plurality of interchangeable lens units 28 which can be interchangeably mounted on a video camera main body 27 store white balance correction data for their own lenses. The video camera body 27 includes white balance correction data memory means 22 and 22X. When one of the plurality of interchangeable lens units 28 is mounted on the video camera body 27, the white balance correction data memory means 2
2, the white balance correction data is read by giving a read clock signal to 22X to form red correction data and blue correction data, and the video is controlled by controlling the white balance adjustment means 13 with the red correction data and blue correction data. Control means 23 and 23X for adjusting the white balance of the signal are provided.

F function Multiple types of interchangeable lens parts for video camera body 27
When you attach the interchangeable lens unit 28 to attach 28,
By reading the white balance correction data from the memory units 22 and 22X, the configuration of the interchangeable lens unit 28 can be simplified, and the control unit on the video camera body side is commonly used for all the interchangeable lens units 28. As a result, a video camera device capable of transmitting a video signal in which a white balance error generated by the attached interchangeable lens unit 28 has been corrected by an optimum white balance correction signal can be easily realized.

G Examples Hereinafter, examples of the present invention will be described in detail with reference to the drawings.

(G1) First Embodiment In FIG. 1, in which parts corresponding to those in FIG. 13 are assigned the same reference numerals, reference numeral 30 denotes a video camera system of an interchangeable lens system as a whole, The white balance correction data memory unit 22 provided corresponding to the lens is mounted. The memory unit 22 stores a ROM (r
and white balance correction data SI for correcting a white balance error due to a spectral characteristic unique to the lens.

The white balance correction data SI is stored in the interchangeable lens unit 28.
Is mounted on the video camera main body 27, and is read out in synchronization with a clock signal CK given from a control circuit 23 (comprising a microcomputer) of the white balance correction circuit 21.

The control circuit 23 reads the white balance correction data
To form a red and blue correction data D ₁ and D ₂ on the basis of SI, respectively digital / red via the analog conversion circuit 25 and 26 and the blue correction signal S _TR and S _TB via interpolated adder circuit to the transmission path Supply to 29A and 29B.

According to the configuration of FIG. 1, when the interchangeable lens unit 28 is exchanged, the white balance correction data SI stored in the white balance correction data memory unit 22 of the interchangeable lens unit 28 is converted to a white balance via the white balance correction circuit 21. is added to the gain control circuit 12A red and blue correction signal S _TR and obtained from 12B and S _TB balancing circuit 13, thereby depending on the interchangeable lens specific spectral characteristics, output color that received proper white balance adjustment The signals S _RO , S _GO and S _BO can be obtained.

(G2) Second Embodiment FIG. 2 shows a second embodiment, in which the same reference numerals are given to the corresponding parts in the first embodiment described above with reference to FIG. In the illustration,
In this case, a white balance correction data memory section 40 is mounted on the video camera body 27 side, and
The white balance correction data for the interchangeable lens units 28 of all models that can be attached to the camera is stored in advance.

In addition to this, a lens identification section 41 is provided on each interchangeable lens section 28 side.
Is mounted, and the lens identification signal ID is transmitted from the lens identification unit 41.
Is supplied to a white balance correction data memory unit 40 mounted on the video camera body 27 side.

In the configuration of FIG. 2, when the photographer attaches the interchangeable lens unit 28 selected as necessary to the video camera body 27, the lens identification unit 41 mounted on the interchangeable lens unit 28 side
, The lens identification signal ID is given as a read control signal to the white balance correction data memory unit 40 mounted on the video camera body 27 side.

In this case the white balance correction data memory section 40 via the digital / analog converter circuits 25 and 26 of the white balance correction data had it occurred designated lens identification signal ID as a red and blue correction data D ₁ and D ₂ addition circuit 29
A and 29B, thus red and blue correction signal _STR
It can be the unique white balance adjustment to the interchangeable lens unit 28, that are installed on the video camera body 27 against and S _TB.

(G3) Third Embodiment FIG. 3 shows a third embodiment, and this configuration is applied to a closed loop type white balance adjustment circuit.

As shown by attaching the same reference numerals to the corresponding parts with FIG. 12,
The video camera system 40 shown in FIG. 3 is equipped with a white balance correction data memory unit 22X having, for example, a ROM structure on the interchangeable lens unit 28X side, and the memory unit 22X is based on the spectral characteristics unique to the lens and the specific spectral characteristics. The white balance correction data SIX to be corrected including the characteristic of the resulting color reproducibility is stored in advance.

This white balance correction data SIX is
When 8X is mounted on the video camera main body 27, it is read out in synchronization with the clock signal CKX given from the control circuit 23X mounted on the video camera main body 27 side, and the red and blue correction data D _1X and _Digital as D _2X /
It is given to the addition circuit 29AX and 29BX are inserted in the feedback loop of the output color signal S _RO and S _BO through analog converter 25X and 26X.

According to the configuration of FIG. 3, when the interchangeable lens unit 28X is exchanged, the inherent white balance error of the interchangeable lens unit 28X can be surely adjusted, including the characteristic of color reproducibility.

(G4) Fourth Embodiment FIG. 4 shows a fourth embodiment. As a component for obtaining the red and blue correction data D _1X and D _2X in the video camera system 40 of FIG. 3, FIG. As described above with respect to the embodiment, a lens identification unit 41X and a white balance correction data memory unit 40X that receives the lens identification signal IDX as an address signal are used.

According to the configuration shown in FIG. 4, when the interchangeable lens unit 28X is attached to the video camera body 27, the lens identification signal IDX is transmitted from the lens identification unit 41X to the white balance correction data memory unit 40X.
Is given as a white balance correction data selection signal, whereby the inherent white balance error of the interchangeable lens unit 28X automatically mounted can be automatically corrected.

(G5) Fifth Embodiment FIG. 5 shows a fifth embodiment. In this case, in the closed loop type white balance adjustment circuit 7, the white lens gap and the like are determined by the photographing lens during the white balance adjustment operation. 1 shows a so-called fully automatic white balance adjustment circuit which can automatically obtain a white signal without photographing a white subject.

In the case of this embodiment, the white balance adjustment circuit 7 converts the output color signals S _RO , S _GO and S _BO into average value calculation circuits 108R and 108G.
And 108B, for example, output signals S _RO , S _GO, and S _BO output from the amplifier circuits 5A, 5B, and 5C during a period corresponding to a video signal of, for example, 6 fields.
_AVR , _SAVG and _SAVB are obtained and input to the operational amplifier circuits 7A and 7B.

Thus the operational amplifier red and blue correction signal obtained from 7A and 7B S _SR and S _CB are inputted to the internal memory M1 and M2 through the switch circuit SW1.

In this way, the red and blue output color signals S _RO and S _BO
When the average value outputs S _AVR and S _AVB obtained based on the average value output S _AVG are not equal to the green average value output S _AVG , the red and blue correction signals S _CR and S _CB for equalizing the average value outputs S _AVG and S _AVG are stored in the internal memory M1 and
The output color signals S _RO , S _GO and
It is possible to automatically adjust the white balance of S _BO.

In addition to such a configuration, the average value outputs S _AVR , S _AVG and S _AVB are output to the reference voltage sources 113R, _113B in the comparison circuits 111R, 111G and 111B.
113G and the reference voltage applied from 113B E _R, is compared with the E _G and E _B, the comparison output S _COMR, S _COMG and S _COMB is supplied to the abnormality judging circuit 112.

The abnormality determination circuit 112 determines whether the white balance of the incident light LA1 is abnormal, for example, when one of the red component, the green component, and the blue component is abnormally large or small compared to the other, or , Average output S _AVR , S _AVG and S _AVB
There reference voltage E _R, unusually high compared to E _G and E _B, or if low summer was like, by which judges this as abnormality supplies an abnormality determination signal S _ST to switch circuits SW1 This is turned off.

Thus, when an abnormality occurs, the white balance operation of the white balance adjustment circuit 7 is automatically interrupted.

A white balance correction data memory unit 22X is mounted on the interchangeable lens unit 28X, and the white balance correction data SIX is read out by a clock signal CKX of a control circuit 23X mounted on the video camera body 27 side.

Control circuit 23X is read on the basis of the white balance correction data SIX, red correction data D _11X, green correction data D _10X and blue correction data D _12X formed respectively by digital / analog conversion circuit 114R, through 114G and 114B comparing the reference voltage E _R, E _G and E _B Te circuits 111R, 111G and 111B
Addition circuits 115R, 115G and
Supplied to 115B.

According to the configuration of FIG. 5, the average value outputs S _AVR , S _AVG and S _AVG
Reference voltages E _R and E _G used to detect _AVB abnormality
And E _B are the red, green, and blue correction data D _11X,
By being modified by specific modifications amount by connexion interchangeable lens unit 28X to D _10X and D _12X, the abnormality judging circuit 112 modifies the criterion to accommodate this each time the interchangeable lens unit 28X is replaced Can output the color signal
A video camera system can be realized in which S _RO , S _GO and S _BO can always be automatically and correctly adjusted in white balance.

(G6) Sixth Embodiment FIG. 6 shows a sixth embodiment, in which the configuration of the white balance correction data memory section 22X and the control circuit 23X of FIG. 5 is replaced with the fourth embodiment of FIG. In the same manner as described above, the lens identification section 41X is mounted on the interchangeable lens section 28X side, and the lens identification signal IDX is transmitted to the video camera body 27.
White balance correction data memory section 40X mounted on the side
Red, green and blue correction data
_Try to get D _11X , D _10X and D _12X .

According to the configuration of FIG. 6, when the interchangeable lens unit 28X is replaced, the red, green, and blue correction data D _11X ,
The fact that D _10X and D _12X can be obtained as data unique to the currently mounted interchangeable lens unit 28X,
The same effects as described above with respect to the drawings can be obtained.

(G7) Specific Configuration of Lens Identification Unit In the case of the embodiment described above with reference to FIGS. 2, 4 and 6, the lens identification unit 41 or 41X is mounted on the interchangeable lens unit 28X side, and the lens identification signal ID or white balance correction data D ₁ connexion to the white balance correction data memory section 40 or 40X mounted on the video camera body 27 side corresponding by the IDX, D ₂ or D _1X, have been made to read out D _2X, the The following configuration can be applied as the lens identification unit 41 or 41X.

First, the lens identification section 41 or 41X shown in FIG. 7 identifies the type of the attached interchangeable lens section 28 or 28X by a mechanical structure, and the interchangeable lens section 28 or 28X.
As shown in FIG. 8, a fitting plate 71 rotatable in the direction of arrow A is used on the rear surface of the X video camera body side.

The fitting plate 71 has a projection 71A at the center, and the fitting plate 71 is inserted in a fitting hole (not shown) provided in the housing of the video camera body 27 and the fitting plate 71 is moved in the direction of arrow A. 180
゜ By rotating, the projection 71A moves to the position 71A '
When rotated, the fitting plate 71 is mounted and held on the housing of the camera body.

Four through-holes 72A, 73A, 74A, and 75A are formed on the surface of the fitting plate 71 at the same radial position at predetermined angular intervals, and the projection 71A of the fitting plate 71 is turned to the rotation position 71A '. When moved, the spring contacts 72B, 73B, 74B and 75B (FIG. 7) provided so as to project from the video camera main body 27 fall into the through holes 72A, 73A, 74A and 74A, respectively.

Between the through-holes 72A, 73A, 74A, and 75A, if necessary, for example, a conductive pattern (formed on the back surface of the fitting plate 71) indicating the model of the interchangeable lens unit 28 or 28X is electrically connected to each other. And electrically connected between the spring contacts that have fallen into the electrically connected through holes.

In the case of the embodiment of FIG. 7, the through holes 72A and 75A are wiring patterns.
The contact points 71B are electrically connected to each other, whereby the spring contacts 72B and 75B are brought into a conducting state, and this conducting state is supplied to the detection circuit 76 as the lens identification signal IDX, thereby transmitting the detection signal S _IDX . .

In this embodiment, when the spring contact 75B is grounded, thereby generating a ground potential at one of the other spring contacts 72B, 73B, or 74B, the spring contact 75B is connected to the currently mounted interchangeable lens unit 28 or 28X. Is input to the detection circuit 76 as a lens identification signal IDX representing the model of the camera.

Secondly, a bar code reading type as shown in FIG. 9 can be applied as the lens identification unit 41 or 41X.

In the case of this embodiment, the fitting plate 71 is, as shown in FIG.
A barcode plate 81 is provided on the surface of the video camera body 27 side.

This barcode plate 81 is used for the interchangeable lens part 28 or 28X.
The bar code pattern is represented as a lens identification signal IDX by the bar code reader 82 and the detection signal S _IDX is transmitted.

According to the configuration shown in FIGS. 9 and 10, it is possible to reliably read the model of the attached interchangeable lens unit 28 or 28X on the video camera main body 27 side using a barcode pattern.

Third, a digital data transmission type as shown in FIG. 11 can be applied as the lens identification unit 41 or 41X.

In this case, the interchangeable lens unit 28 or 28X
It has a lens identification data memory 91 for storing lens identification data representing the model of 8 or 28X, and the interchangeable lens unit 28 or 28X
When is mounted on the video camera body 27, the lens identification signal from the control circuit 92 mounted on the video camera body 27 side
The lens identification data D _IDX is read out by the read clock signal CK _IDX given as _IDX, and is taken into the control circuit 92 as the lens identification signal IDX so that the detection signal S _IDX is transmitted from the control circuit 92. It has been done.

Even if configured as shown in FIG. 11, the interchangeable lens unit 28 or 28X
Thus, the lens identification signal unique to the lens can be reliably taken into the video camera body 27 side.

H Advantageous Effects of the Invention As described above, according to the present invention, when a plurality of types of interchangeable lens units are mounted on a video camera body, when the interchangeable lens units are mounted, the white balance correction data memory provided in the interchangeable lens unit By providing a read clock signal to the means, the white balance correction data is read to the video camera body side,
The interchangeable lens section can be simplified, and the control means on the video camera body side can be used in common for all the interchangeable lens sections, thereby reducing the white balance error caused by the attached interchangeable lens section to the optimum white lens. A video camera device capable of transmitting a video signal corrected by the balance correction signal can be easily realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a video camera system according to the present invention, FIGS. 2 to 6 are block diagrams showing another embodiment, and FIGS. 7 to 11 are schematic lines showing a specific structure of a lens identification unit. FIGS. 12, 13 and 13 are block diagrams showing a conventional video camera system. 13 White balance adjustment circuit 21 White balance correction circuit 22, 22X White balance correction data memory section 23 23X Control circuit 28 28X Interchangeable lens section 30, 40 50 …… Video camera system, 40, 40
X: White balance correction data memory section, 41, 41X ...
... Lens identification unit.

Claims (1)

(57) [Claims] 1. An interchangeable lens section for receiving incident light, a video camera body, and signal processing means provided on the video camera body for transmitting a video signal in response to incident light incident from the interchangeable lens section. A video camera apparatus having a white balance adjusting means for adjusting a white balance based on a signal from the signal processing means; The video camera body has white balance correction data memory means for storing correction data.
When one is mounted on the video camera body, the white balance correction data is read out by applying a read clock signal to the white balance correction data memory means to form red correction data and blue correction data, and the red correction data and A video camera device comprising a control unit for adjusting the white balance of the video signal by controlling the white balance adjustment unit with blue correction data.