JPH06121321A - Image pickup device - Google Patents

Abstract

PURPOSE:To attain a satisfactory white balance adjustment by adjusting a white balance by using a light entering from a diffusing plate which can be freely opened and closed, and picking up an image while the adjusted white balance is held. CONSTITUTION:When each circuit is turned to a normal state, a CPU 17 confirms that a cover 11 is closed, confirms that the output of a contrast detecting circuit 16 is not swung out to either side, and then controls the amplification level of each signal of an amplifier circuit 14 so that each chrominance signal of the amplifier circuit 14 can have the same amplitude. The CPU 17 confirms that the discriminated output signal of the white balance inputted from the circuit 16 is matched, and changes the level of a white balance adjustment signal transmitted to a white balance comparison discriminating circuit 161 into an LOW level. Then, the amplification level of the circuit 14 is fixed. The CPU 17 opens the cover 11, confirms that the cover 11 is opened, and outputs a photographed video signal, after the white balance adjustment routine is ended.

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 white balance adjusting means for an image pickup apparatus mounted on a workstation or the like.

[0002]

2. Description of the Related Art Conventionally, since an image pickup apparatus of this type uses a general video camera or the like, the white balance is adjusted based on color information from a photographed subject.

[0003]

However, the above-mentioned conventional example has the following problems. In other words, this type of imaging device is usually used in a room because it is attached to a workstation (generally), and it is not so wide-angle to photograph a person who normally operates the workstation as a subject. With the adjustment device, the white balance may not be properly adjusted due to the color of clothes of the subject or the color of the wall in the room.

The object of the present invention is to solve the above-mentioned problems,
An object of the present invention is to provide an imaging device capable of performing favorable white balance adjustment without being affected by the color of clothes of a person who is a subject, the color of a background wall, and the like.

[0005]

In order to achieve the above object, the present invention provides an image pickup means for converting an optical image of an object formed through a lens into an image pickup signal, and the lens attached to the front surface of the lens. A semi-transparent diffuser-like lens cover movable from the front surface of the lens, lens cover moving means for moving the lens cover, and image pickup of the image pickup means taken through the lens cover and the lens during white balance adjustment At least one signal level of the signal is made variable, and the respective signal levels of the output signals of the respective colors output from the amplifying means are compared,
Amplification factor varying means for varying the amplification factor of the amplifying means for the output signal components of the respective colors so that the difference in the signal level is minimized, and the lens cover is positioned in front of the lens for white balance adjustment. A control means for activating the amplification means and the amplification factor varying means, and moving the lens cover from the lens through the lens cover moving means to perform imaging of a subject after white balance adjustment. Characterize.

[0006]

According to the present invention, a white opaque semi-transparent cover which is electrically opened and closed is mounted on the front surface of the image pickup lens, and when the image pickup apparatus is turned on, an image is taken through the cover to minimize the difference in color signal level. After adjusting the amplification factor of each color signal component so that the above, the cover is opened and the photographing of the subject is started. In this way, since the white balance is adjusted using the light incident from the diffuser plate, good white balance can be achieved without being affected by the color of clothes, the color of the back shadow, etc. of the person who is the subject.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows an external configuration of a workstation device using an image pickup device to which the present invention is applied. 4 is a workstation device, 3 is a local area network or ISDN connected to the workstation device 4.
And the like, 8 is a storage device, 5 is an image pickup device having a white balance adjusting device according to the present invention, and 6 is this image pickup device 5
The microphone 7 collects the voice signal of the subject, and the speaker 7 outputs the voice signal sent from the line 3 and the voice signal recorded in the storage device 8 as an audible signal.

FIG. 2 shows a circuit configuration of the image pickup device 5 shown in FIG. Here, 11 is a semi-transparent lens cover that is clouded in order to protect the imaging lens 12 and achieve white balance.
Reference numeral 3 denotes a CCD (charge coupled device) as an image pickup element for picking up an image, and 14 amplifies the image pickup signal output from the CCD 13 to output respective input signals (for example, Y, Cy, Mg signals or R, G, B signals). An amplifier circuit that controls the white balance by varying the amplitude and the like, 15 is a video signal processing circuit that processes the output signal of the amplifier circuit 14 and outputs it as a Y signal and a color difference signal or an RGB signal, and 16 is an amplifier circuit 14
Amount of light input to CCD 13 from the output signal of CCD and CCD 1
A contrast detection circuit for detecting the contrast of the image pickup signal taken in No. 3, 161 compares the output levels of the respective signals output from the amplifier circuit 14 and outputs the comparison result, and the comparison result is higher than a certain level. If it is smaller, the white balance comparison / determination circuit outputs a signal indicating that the white balance is correct. Further, 17 is a CPU (central processing unit) that controls the entire imaging device 5, 18 is an iris control circuit that receives a control signal from the CPU 17 and controls the iris of the imaging lens 12, and 19 is an iris control circuit. A lens control circuit that receives a control signal from the CPU 17 and drives the imaging lens 12 to control the focus of the imaging signal projected on the CPU 13.
0 is the lens cover 11 according to the control signal from the CPU 17.
Is a lens cover opening / closing device for opening and closing the device, 21 is a video signal output terminal, and 22 is a command input / output terminal for exchanging commands with the workstation device 4.

FIG. 3 shows a specific example of the lens cover 11 and its cover opening / closing device 20 shown in FIG. Where 11 (A)
Is a lens cover in a closed state, 11 (B) is a lens cover in an open state, 23 is a lens cover opening / closing detection device in which a push switch-like switch is attached to a contact portion with the lens cover 11, and 20 is the lens cover 11 (A)
The plunger is a lens cover opening / closing device that is pressed to lift the lens cover 11 (B).

FIG. 4 shows a circuit configuration example of the amplifier circuit 14 of FIG. Here, 100 is a G (green) signal input terminal, 101 is a B (blue) signal input terminal, and 102 is an R terminal.
A (red) signal input terminal, 103 is a fixed amplifier circuit that amplifies the G signal input to the input terminal 100 by a predetermined amount, and 104 is a variable amplifier control circuit to be described later for the B signal input to the input terminal 101. A variable amplifier circuit that amplifies based on the output signal of 112, and 105 is a variable amplifier control circuit 111, which will be described later, for the R signal input to the input terminal 102.
Of the output signal of the amplifier circuit 103, 106 is a differential amplifier circuit that amplifies the difference between the output signal of the amplifier circuit 103 and the output signal of the variable amplifier circuit 104, and 107 is the output signal of the amplifier circuit 103 and the variable amplifier circuit. A differential amplifier circuit that amplifies the difference between the output signals of 105.

Reference numeral 108 is a reference voltage source, 109 is a comparison between the output signal of the differential amplifier circuit 106 and the output voltage of the reference voltage source 108, and the output voltage of the differential amplifier circuit 106 is the reference voltage source 108. A comparator circuit that outputs a HIGH (high) signal if the output voltage is higher than the output voltage and a LOW (low) signal if the voltage is lower than the output voltage. Reference numeral 110 is a differential circuit that compares the output signal of the differential amplifier circuit 107 with the output voltage of the reference voltage source 108. It is a comparator circuit that outputs a HIGH signal when the output voltage of the amplifier circuit 107 is higher than the output voltage of the reference voltage source 108, and outputs a LOW signal when the output voltage is low. Variable amplifier control circuit 111
In accordance with the output signal of the comparator circuit 109, up counts if the output of the comparator circuit 109 is HIGH for each clock input from the clock input terminal 126 for inputting a clock for performing white balance, and is LOW if LOW. If it counts down, the count data is D / A (digital / analog) converted and output to the variable amplifier circuit 104. According to the output signal of the comparator circuit 110, the variable amplifier control circuit 112 counts up if the output of the comparator circuit 110 is HIGH for each clock input to the clock input terminal 126, and if it is LOW, counts down and counts down. Variable amplification circuit 105 by D / A converting data
Output to.

Reference numeral 113 denotes a voltage shift circuit for shifting the output voltage of the reference voltage source 108 by a certain voltage above and below and outputting the voltage, and 114 denotes the differential amplifier circuit 106 and the differential amplifier circuit 10.
7 is a maximum value selection circuit for comparing the output signals and selecting the larger one of the output signals, and 105 is a differential amplifier circuit 106.
Is a minimum value selection circuit that compares the output signal of the differential amplifier circuit 107 with the output signal of the differential amplifier circuit 107 and selects and outputs the smaller one of the output signals. 1
Reference numeral 18 compares the output signal of the maximum value selection circuit 114 with the output signal of the voltage shift circuit 113 to compare the maximum value selection circuit 114.
Comparator circuit 119 that outputs a HIGH signal when the output signal of is larger than that of the voltage shift circuit 113, and outputs a LOW signal when the output signal of the voltage shift circuit 113 is larger.
Is the output signal of the minimum value selection circuit 116 and the voltage shift circuit 1
13 is compared with the output signal of 13 and a LOW signal is output when the output signal of the minimum value selection circuit 116 is larger, and H is output when the output signal of the voltage shift circuit 113 is larger.
It is a comparator circuit that outputs an IGH signal. 12
Reference numeral 0 is an OR circuit that performs a logical sum operation of the output signal of the comparator circuit 118 and the output signal of the comparator circuit 119.

Reference numeral 122 is an output terminal for outputting a G'signal in which the G signal input to the input terminal 100 is amplitude-amplified by a fixed level by the fixed amplification circuit 103, and 123 is a variable B signal input to the input terminal 101. Amplifier circuit 104
An output terminal for outputting the B ′ signal amplified by 12
Reference numeral 4 is an output terminal for outputting an R'signal in which the R signal input to the input terminal 102 is amplified by the variable amplifier circuit 105. Further, 125 is a white balance control ON for controlling whether or not to perform white balance control.
A / OFF signal input terminal 127 is a white balance good / bad determination output terminal that outputs a signal of a determination result as to whether or not the white balance is correct.

Next, the white balance control operation in one embodiment of the present invention having the above-mentioned configuration will be described with reference to the flow chart shown in FIG.

First, when the power supply of the apparatus is off, the circuits shown in FIGS. 2 and 4 do not operate, and the plunger 20 of FIG. 3 is not energized, so the lens cover 11 is shown in FIG. As shown in 3 (11), the lens 12
Exists on the front surface of the lens and protects the lens 12.

When the power is turned on, each circuit is energized to start up the circuit, and the CPU 17 is reset (step S1). When a certain period of time elapses and each circuit enters a steady state, the CPU 17 is reset. Confirms that the cover 11 is closed based on the input signal from the cover open / close detection device 23 (step S2), and confirms that the output of the contrast detection circuit 16 is not swung to either side (step S2). S4) and the white balance adjustment routine (step S6). That is, when it is confirmed that the cover 11 is closed, a control signal is sent to the input terminal 125 and a clock is sent to the input terminal 126 so that the white balance comparison / determination circuit 161 adjusts the white balance. When the white balance comparison / determination circuit 161 receives the control signal, it compares the levels of the respective color signals input from the amplification circuit 14, for example, the signals such as RGB signals, and the amplification circuit 14 outputs the same amplitude. Controls the amplification level of each signal.

If the cover 11 is not closed in step S2, the cover 11 is closed (step S2).
3) A control signal is sent to the cover opening / closing device 20, and when the cover 11 is still not closed, a command to that effect is output to the workstation 4 of FIG.

Further, in the above step S4, only one level of the signal whose amplification factor is fixed (in this embodiment, G
If the signal) has been swung out, the iris control circuit 18 controls the iris of the imaging lens 12 based on the signal from the contrast detection circuit 16 (step S5), and confirms that the signal amplitude cannot be swung out. Did (step S
In the 4) state, the amplifier circuit 14 performs white balance adjustment (step S6).

When the CPU 17 confirms that the white balance determination output signal input from the contrast detection circuit 16 is determined to be correct (for example, LOW level) (step S7), white balance comparison is performed. The white balance adjustment control signal sent to the determination circuit 161 through the input terminal 125 is, for example, LOW.
Change to level. White balance adjustment control signal is L
When changing to the OW level, the variable amplifier control circuits 111, 1 that increase or decrease the amplification level of each color signal of the amplifier circuit 14
The output voltage levels of 12 are held in the state at that time, whereby the amplification levels of the amplifier circuits 14 are fixed (step S8).

When the white balance adjustment routine is completed in this way, the CPU 17 sends a control signal to the cover opening / closing device 20 to open the cover 11, opens the cover 11 (step S9), and causes the cover opening / closing detection device 23 to cover. As shown in 11B of FIG. 3, when it is confirmed that 11 is opened, the video signal processing circuit 15 picked up in this state
The output video signal of is output from the output terminal 21.

When a command is received from the workstation 4 to adjust the white balance, the white balance can be adjusted even while the power is on by executing the above-mentioned routine. is there.

(Other Embodiments) For example, as shown in FIG. 6, the image pickup device 20 attached to the workstation 205 through a communication line 203 such as a LAN by keyboard input from a workstation 201 at a remote place.
It is also possible to activate the white balance adjusting apparatus according to the present invention of No. 6 and adjust the white balance of the camera of the image pickup apparatus 206.

[0024]

As described above, according to the present invention,
The white balance is adjusted using the light incident from the openable / closable diffusion plate, and the adjusted white balance state is maintained so that the image is taken. Since the white balance can be adjusted without being affected by colors and the like, good white balance can always be performed. Further, since the diffusion plate for white balance adjustment also serves as the lens cover, it is possible to reduce dust adhesion and dirt on the lens.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an external configuration of a workstation device equipped with an imaging device (camera) to which the present invention is applied.

FIG. 2 is a block diagram showing a circuit configuration of the image pickup apparatus of FIG. 1 incorporating the white balance adjusting means of the present invention.

FIG. 3 is a front view of the essential parts showing a specific configuration example of the lens cover and the cover opening / closing device of FIG.

FIG. 4 is a block diagram showing a circuit configuration example of the amplifier circuit of FIG.

FIG. 5 is a flowchart showing a control operation when performing white balance adjustment in one embodiment of the present invention.

FIG. 6 is a configuration diagram showing a system configuration of another embodiment of the present invention.

[Explanation of symbols]

 3 lines 4 workstation device 5 image pickup device 6 microphone 7 speaker 8 storage device 11 lens cover (translucent diffuse plate with cloudiness) 12 image pickup lens 13 CCD (image pickup device) 14 amplification circuit 15 video signal processing circuit 16 contrast detection circuit 17 CPU 18 Iris control circuit 19 Lens control circuit 20 Lens cover opening / closing device (plunger) 21 Video signal output terminal 22 Command input / output port 23 Cover opening / closing detection circuit 103 G signal fixed amplification circuit 104 B signal variable amplification circuit 105 R signal Variable amplifier circuit 106,107 Differential amplifier circuit 108 Reference voltage source 109,110 Comparator circuit 111,112 Variable amplifier control circuit 125 White balance control signal input terminal 127 White balance pass / fail judgment output terminal 161 White Lance comparison judgment circuit

Claims (1)

[Claims] 1. An image pickup means for converting a light image of a subject formed through a lens into an image pickup signal, and a semitransparent diffuser-like lens cover attached to the front surface of the lens and movable from the front surface of the lens. And a lens cover moving means for moving the lens cover, and at least one signal level of an image pickup signal of the image pickup means taken through the lens cover and the lens at the time of white balance adjustment can be made variable. The amplification means and the signal levels of the output signals of the respective colors output from the amplification means are compared, and the amplification factor of the amplification means of the output signal components of the respective colors is changed so that the difference between the signal levels is minimized. And a gain adjusting means for positioning the lens cover in front of the lens for white balance adjustment. Start, and imaging apparatus after the white balance adjustment, characterized by comprising a control means for causing the image of an object by moving the lens cover from the lens through the lens cover moving means.