JPH0329357B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a color television (hereinafter abbreviated as TV) imaging device, in particular, to a color separation striped filter that extends to the photoelectric conversion surface of an image pickup tube. The present invention relates to a color imaging device configured to be provided in an optical path.

(Prior art) A color-separating striped filter is provided in the optical path up to the photoelectric conversion surface of the image pickup tube, and a striped color-separated image of the object to be imaged is provided onto the photoelectric conversion surface of the image pickup tube. 2. Description of the Related Art Case-type color imaging devices that generate multiplexed signals have been known for some time.

(Problems to be Solved by the Invention) By the way, there is a color imaging device in which a color separation striped filter is provided in the optical path up to the photoelectric conversion surface of the above-mentioned image pickup tube, and a color multiplexed signal is generated from the image pickup tube. , if the speed of the electron beam scanning the photoelectric conversion surface of the image pickup tube changes, the frequency of the color multiplexed signal output from the image pickup tube changes,
This causes color errors in the image reproduced by the color demodulated color signals.

The speed of the electron beam scanning the photoelectric conversion surface of the image pickup tube is changed according to the charge pattern on the photoelectric conversion surface, so the color multiplexed signal output from the image pickup tube is The frequency of changes depending on the charge pattern on the photoelectric conversion surface of the optical image pickup tube. Color shift occurs in areas where the amount of charge changes suddenly on the surface.

FIG. 6 is a diagram for explaining the above-mentioned problem, and a in FIG. 6 is an optical image given to the photoelectric conversion surface T in the image pickup tube. A case is shown in which the optical image applied to the surface T consists of an area shown as black and an area shown as white.

Assuming that the optical image given to the photoelectric conversion surface T of the image pickup tube is as shown in a of FIG. 6, the charge pattern on the photoelectric conversion surface T of the image pickup tube is as follows.
The potential of the surface of the photoelectric conversion surface T of the image pickup tube on which the scanning electron beam impinges corresponds to the optical image applied to the photoelectric conversion surface T of the image pickup tube. It is low in the part corresponding to the black area in the photoelectric conversion surface T of the image pickup tube, and high in the part corresponding to the white area in the optical image given to the photoelectric conversion surface T of the image pickup tube. The speed is the photoelectric conversion surface T of the image pickup tube.
In the part where the potential changes from a low part to a high part, that is, in the part where the optical image given to the photoelectric conversion surface T of the image pickup tube changes from a black area to a white area, , contrary to the above,
A portion where the potential of the photoelectric conversion surface T of the image pickup tube changes from a high portion to a low portion, that is, a portion where the potential changes from a white area to a black area in the optical image given to the photoelectric conversion surface T of the image pickup tube. It's slow in some parts.

Therefore, the color multiplexed signal output from the image pickup tube is transmitted to the photoelectric conversion surface T of the image pickup tube, as shown in FIG.
The phase advances in the part where the light image given to the photoelectric conversion surface T of the image pickup tube changes from the black region to the white region. The phase lags in the portion where the area changes to the black area, and therefore color shift occurs at the boundary portion where the brightness changes in the reproduced image.

(Means for Solving the Problems) The present invention includes a color separation striped filter consisting of a predetermined arrangement of a plurality of types of color stripes in the optical path up to the photoelectric conversion section of the image pickup tube. In a color imaging device capable of generating a color multiplexed signal, there is provided a means for obtaining an edge signal from a luminance signal obtained based on a color multiplexed signal as described above, and a charge pattern in a photoelectric conversion section of an image pickup tube. and means for correcting time axis fluctuations occurring in the color multiplexed signal due to changes in scanning speed occurring in the scanning electron beam, using a control signal obtained based on the edge signal of the luminance signal. It provides equipment.

(Example) Hereinafter, specific contents of the color imaging device of the present invention will be described in detail with reference to the accompanying drawings.

1 to 4 are block diagrams of different embodiments of the color imaging device of the present invention, and in each of these figures, corresponding components are designated by the same drawing reference numerals. There is.

In the figure, O is the object to be imaged, 1 is the imaging lens, 2 is the imaging tube, 3 is the deflection yoke, 4 is the photoelectric conversion section of the imaging tube (target having a photoelectric conversion surface),
F is a color separation striped filter, 5 is the front plate of the image pickup tube,
PrA is a preamplifier, LPF is a low-pass filter (low-pass filter), and BPF is a band-pass filter (bandpass filter).
The optical image of the object to be imaged is given to the photoelectric conversion unit 4 of the image pickup tube 2 via the color separation striped filter F, and from the image pickup tube 2, a DC component and a color multiplex carrier wave having a specific repetition frequency are output. An output signal (color multiplexed signal) of the image pickup tube is output, which includes a modulated wave whose amplitude and phase are modulated by the signal.

The signal form of the color multiplexed signal outputted from the image pickup tube 2 is such that the color separation striped filter F provided in the optical path up to the photoelectric conversion section 4 of the image pickup tube 2
Needless to say, the configuration differs depending on what kind of configuration is used.

In Fig. 1, the output signal from the image pickup tube 2 is amplified by a preamplifier PrA, and then a low-pass filter LPF.
and the bandpass filter BPF and the lowpass filter
The LPF outputs the luminance signal Sy and sends it to the terminal 6, as well as the delay circuit DL1 and the subtracter.
Supplied to SUB. In addition, from the bandpass filter BPF, a color multiplex carrier wave having a specific repetition frequency is output as a modulated wave Sc whose amplitude and phase are modulated by the signal.
is output, and is supplied to the variable delay circuit VDL via a delay circuit DL2 provided as necessary.

The delay circuit DL1, to which the luminance signal Sy output from the low-pass filter LPF is supplied as described above, generates a delayed luminance signal Syd in which a slight time delay Δt1 is given to the luminance signal Sy described above {Fig. b reference } and gives it to the subtractor SUB as the minuend signal.

Furthermore, since the subtractor SUB described above is supplied with the luminance signal Sy {see a in FIG. 5} as a subtraction signal, the subtracter SUB outputs an edge signal (see c in FIG. 5) of the luminance signal ( Syd−Sy) and supplies it to the control signal generation circuit CSG.

In the control signal generation circuit CSG described above, based on the edge signal (Syd−Sy) given to it,
Generates a control signal Sp {d in FIG. 5} in a predetermined signal form and supplies it to the variable delay circuit VDL,
The control signal Sp generated by the control signal generation circuit CSG described above has a signal form suitable for correcting the phase distortion of the image pickup tube output signal. Furthermore, a luminance signal is also supplied to the control signal generation circuit CSG through the path shown by the dotted line in the figure, and the phase distortion that occurs due to fluctuations in the signal level of the luminance signal is also corrected. Such a control signal may be generated from the control signal generation circuit CSG.

The variable delay circuit VDL to which the control signal Sp generated from the control signal generation circuit CSG described above is applied is as follows:
By changing the phase of the modulated wave Sc in the color multiplexed signal inputted thereto as shown in e in FIG. Correspondingly, the time axis variation occurring in the color multiplexed signal due to the change in scanning speed occurring in the scanning electron beam is corrected.

The time Δtt2 shown in FIG. This is a time delay given to the modulated wave Sc in the color multiplexed signal in order to ensure that the phase of the modulated wave Sc in the color multiplexed signal is corrected by Sp. The time delay Δt2 may be provided by the delay circuit DL2, but if the time delay Δt2 can be obtained by another circuit provided in the signal path, there is no need to provide the delay circuit DL2. .

In FIG. 1, the luminance signal Sy output to the output terminal 6 and the modulated wave Sc in the color multiplexed signal output from the variable delay circuit VDL to the output terminal 7 are processed by subsequent color signal processing (not shown). After being processed in a certain way in the circuit, the target is
It is converted into a color video signal according to the TV system. When the color imaging device shown in FIG. 1 is constructed according to the so-called step energy method, the signal output from the output terminal 7 shown in FIG. No. Publication,
The signal processing may be performed by applying the signal to a color signal demodulation circuit shown in Japanese Patent Publication No. 55-33233, Japanese Patent Publication No. 59-35550, and the like.

Next, the embodiment shown in FIGS. 2 and 3 will be described. These Figures 2 and 3 are from JP-A-59-
A color imaging device as disclosed in FIG. 4 of Publication No. 153392, that is, consists of a repetition of a specific arrangement pattern of a plurality of types of colored strips each having a predetermined strip width, and a repetition of the said arrangement pattern. a color separation striped filter in which the colors of each of the plurality of color stripes are set so that the phase of the fundamental wave component of the image pickup tube output signal, which is determined in accordance with the color of the light, changes depending on the color of the light; a configuration arrangement provided in an optical path up to a photoelectric conversion section of an image pickup tube, so that an optical image of an object to be imaged is given to the photoelectric conversion section of the image pickup tube via a color separation striped filter; A storage device capable of arbitrarily storing information signals corresponding to at least one frame period of the output signals of the image pickup tube is provided, and prior to imaging, an arbitrary specific color is imaged and at least one of the image pickup tube output signals is stored. An information signal corresponding to a frame period is stored in the storage device, and a reference wave for color signal demodulation is obtained based on the information signal stored in the storage device, thereby synchronizing from the output signal of the image pickup tube. In a color imaging device that demodulates a predetermined color signal by detection or the like, one of the two signals is the information signal obtained by reading out the information signal stored in the storage device and the output signal of the image pickup tube. With one signal of
When the present invention is applied to a color imaging device provided with a means for controlling the change mode of the other signal on the time axis to match the change mode of one signal on the time axis as a reference. This is an example.

In Figures 2 and 3, MTX is a matrix circuit, SDET1 and SDET2 are synchronous detectors,
MA is a storage device, FMDC is an FM detection comparison circuit,
CD is a carrier start position detection circuit, and SSG is a reference signal generator.For details of the circuit layout and operation of each of these components, please refer to the above-mentioned Japanese Patent Application Laid-Open No. 153392/1983. Good to be referenced.

The storage device MA shown in FIG. 2 and FIG. An information signal corresponding to at least one frame period of the image pickup tube obtained by imaging an arbitrary specific color is stored, and when the color imaging device starts imaging, the stored information signal is stored. In the storage device MA shown in the figure, ADC is an analog-to-digital converter, and DM is a digital converter. Memory and DAC are digital-to-analog converters, OSCa is an address signal generator, and OSCc is a clock signal generator.

In addition, the carrier start position detection circuit CD is
It is configured with a function that can generate a signal that corresponds to the rising point of the fundamental wave component of the color multicarrier in the output signal of the image pickup tube. It can be configured using

The FM detection comparison circuit FMDC is configured to have the function of outputting a signal indicating the polarity and magnitude according to the frequency difference between two signals. and a comparator that compares the output signals from the two frequency discriminators.

Furthermore, the reference signal generator SSG generates a synchronous detector based on the signal sent from the storage device MA.
Synchronous detectors SDET1 and SDET generate continuous reference signals each having a predetermined phase required when demodulating the color signal in SDET1 and SDET2.
For example, it may be configured by a synchronous oscillator including a phase-locked loop and a phase shifter.

In FIGS. 2 and 3, the storage device MA stores data obtained by imaging an arbitrary specific color (the color of an arbitrary specific color strip in the color separation striped filter) prior to imaging the object to be imaged. The fundamental wave component of the color multicarrier in the output signal of the image pickup tube (bandpass filter)
An information signal corresponding to at least one frame period of the signal component (signal component that has passed through the BPF) must be stored, but this information signal can be stored by operating a predetermined operation button on an operation section (not shown) provided on the color imaging device. It is done by twisting.

That is, when a predetermined operation button on the operation unit provided in the color image pickup device is operated, a fundamental wave component of a color multicarrier wave having a predetermined phase is generated in the output signal of the image pickup tube in the color image pickup device. For example, a specific color of light is automatically applied to the image pickup tube, and the storage device MA is set to storage mode, so that the signal component of the output signal of the image pickup tube 2 that has passed through the bandpass filter BPF is digitalized. stored in memory.

The analog-to-digital converter ADC converts data by sampling pulses given from a pulse source (not shown).
An AD conversion operation is performed to provide a digital signal to a digital memory, and the digital memory DM stores the provided digital signal. It goes without saying that the storage of sequential digital signals in the digital memory DM is performed by the address signals generated by the address signal generator OSCa, and the address signal generator OSCa is generated by the clock signal generator OSCa. It is operated by the clock signal provided by the clock.

When the storage device is put into the storage mode and an information signal corresponding to one frame period has been stored in its digital memory DM, the storage device MA is put into the read mode and the information signal corresponding to one frame period is stored from the digital memory DA. The correspondingly stored information signal is read out repeatedly, converted into an analog signal by the digital-to-analog converter DMC, and applied to the reference signal generator SSG, which converts the applied signal into an analog signal. Based on this, reference signals for synchronous detection (for color signal demodulation) each having a predetermined phase are generated.

If the mode of scanning by the electron beam in the image pickup tube 2 is always constant, a correct color signal can always be obtained by using the base signal created based on the information signal read from the storage device MA as described above. However, the stability of the deflection circuit and deflection yoke in a color imaging device is insufficient, and as a result, the scanning mode of the electron beam changes depending on the external magnetic field. Since the scanning mode of the electron beam changes due to other causes, the information signal stored in advance in the storage device MA is read out as described above, and the reference signal created based on it is used for color demodulation. Even if this is done, it is not always possible to obtain a good color signal.
In the illustrated color imaging device, first, the storage device MA
The carrier start position detection circuit CD and FM detection are compared so that the manner of change on the time axis of the information signal read from the image pickup tube changes in accordance with the manner of change on the time axis of the output signal from the image pickup tube. circuit
Components such as FMDC, storage device MA, reference signal generator SSG, and synchronous detectors SDET1 and SDET2 are made to operate.

Here, in the circuit layout shown in FIG. 2, the operation of the circuit layout with components such as the delay circuit DL1, the subtracter SUB, the control signal generation circuit CSG, and the variable delay circuit VDL omitted, and the operation of the circuit layout shown in FIG. The operation of the circuit arrangement shown in FIG. 3 in which components such as the delay circuit DL1, the subtracter SUB, the control signal generation circuit CSG, and the variable delay circuits VDL1 and VDL2 are omitted will be described.

When the device is in the imaging mode and an information signal is read out from the storage device MA, the output signal from the bandpass filter BPF is sent to the synchronous detectors SDET1 and SDET2 and the carrier start position detection circuit CD and When applied to the FM detection comparison circuit FMDC, the digital memory DA of the storage device MA
The reference signal generated by the reference signal generator SSG based on the signal read from the DAC and converted into an analog signal by the digital-to-analog converter DAC is given to the synchronous detectors SDET1 and SDET2, and
Provided to FM detection comparison circuit FMDC, etc. FM
In the detection comparison circuit FMDC, the 2
A signal, that is, a signal corresponding to the frequency difference between the reference signal generated from the reference signal generation circuit SSG and the output signal from the bandpass filter BPF, is outputted to the clock signal generator in the storage device MA.
OSCc, the period of the clock signal generated by the clock signal generator OSCc is changed in the direction in which the frequency difference between the two signals described above becomes zero. Also,
The carrier start position detection circuit CD to which the output signal of the bandpass filter BPF is applied gives an output pulse to the address signal generator OSCs in the storage device MA to reset it at the point in time when the beam blanking period ends and the carrier appears. , to ensure correct centering movement.

In addition, by changing the period of the clock signal of the clock signal generator OSCc by the output signal of the FM detection comparison circuit FMDC, the reference signal generator
The reference signal supplied from the SSG to the synchronous detectors SDET1 and SDET2 exhibits a time axis variation similar to that of the output signal of the bandpass filter BPF, and is always correct from the synchronous detectors SDET1 and SDET2. It operates so that color signals are output.

However, the above-mentioned operation of the above-mentioned components prevents time-axis fluctuations that occur in the color multiplexed signal due to changes in the scanning speed that occur in the scanning electron beam in response to the charge pattern in the photoelectric conversion section of the image pickup tube. Since the correction is not well performed, the color image pickup device of the present invention is able to compensate for the time axis fluctuations that occur in the color multiplexed signal due to the change in scanning speed that occurs in the scanning electron beam in response to the charge pattern in the photoelectric conversion section of the image pickup tube. In order to ensure good correction, a bandpass filter is used in the embodiment shown in the second figure.
A variable delay circuit VDL is provided in the signal transmission path from the BPF to the synchronous detectors SDET1 and SDET2, and the luminance signal Sy obtained from the output signal of the amplifier PrA through the low-pass filter LPF is connected to the delay circuit DL1 and the subtraction circuit. SUB and the edge signal is generated, and the edge signal is sent to the control signal generation circuit.
CSG to generate a control signal based on the edge signal, and the time delay of the variable delay circuit VDL described above is controlled by the control signal generated from the control signal generation circuit SSG. 3
In the illustrated embodiment, a reference signal generator
Individual variable delay circuits VDL in each signal transmission path from SSG to synchronous detectors SDET1 and SDET2
1. VDL2 is provided, and the luminance signal Sy obtained from the output signal of the amplifier PrA through the low-pass filter LPF is supplied to the delay circuit DL1 and the subtraction circuit SUB so that an edge signal is generated. The edge signal is given to the control signal generation circuit CSG to generate a control signal based on the edge signal, and the time delay of the variable delay circuits VDL1 and VDL2 is controlled by the control signal generated from the control signal generation circuit SSG. I try to do that.

Variable delay circuit in the circuit arrangement shown in the second diagram
The operation of each component such as VDL, delay circuit DL1, subtraction circuit SUB, and control signal generation circuit CSG is as follows.
Variable delay circuit VDL, delay circuit DL1, subtraction circuit SUB in the circuit arrangement explained with reference to FIG.
The operation of the components of each part such as the control signal generation circuit CSG is the same, and the variable delay circuits VDL1 and VDL2 and the delay circuit in the circuit layout shown in Figure 3 are the same.
The effect of correcting the time axis fluctuation of the color multiplexed signal obtained by the operation of each component such as DL1, the subtraction circuit SUB, and the control signal generation circuit CSG is also the same as the circuit operation already described with reference to Fig. 1. This is similar to the effect of correcting the temporal variation of the color multiplexed signal obtained in this way.

That is, in the circuit arrangement shown in the second diagram, the time axis of the color multiplexed signal itself is changed by the control signal, as in the case of the circuit arrangement shown in the first diagram, whereas the circuit arrangement shown in the third diagram In the arrangement, the time axis of the color multiplexed signal remains the same, but the time axis of the reference signal is changed, so as a result, the time axis of the color multiplexed signal is changed by the control signal. This is because the state is equivalent to

It goes without saying that in FIGS. 2 and 3, the matrix circuit MTX outputs predetermined primary color signals to terminals 8 to 10, respectively (see Japanese Patent Laid-Open No. 153392/1983).

Next, the embodiment shown in FIG. 4 will be described. In FIG. 4, a light image of the object to be imaged is passed through a color separation striped filter F to an image pickup tube 2 (the image pickup tube 2 used in the embodiment shown in FIG. 4 has an electrostatic deflection type configuration). )
The output from the image pickup tube 2 includes a DC component and a modulated wave in which a color multiplex carrier wave having a specific repetition frequency is amplitude- and out-of-phase modulated by the signal. A signal (color multiplexed signal) is output.

In Fig. 4, the output signal from the image pickup tube 2 is amplified by a preamplifier PrA, and then a low-pass filter LPF.
and the bandpass filter BPF and the lowpass filter
A luminance signal Sy is outputted from the LPF and sent to the terminal 6, and is also supplied to the delay circuit DL3.

The delay circuit DL3 described above operates for a time (1H−) shorter than one horizontal scanning period (1H) by a small amount of time Δt.
A time delay of Δt) is also used that gives the luminance signal a time delay. The luminance signal output from the delay circuit DL3 is supplied to the delay circuit DL1 and the subtracter SUNB.

In addition, from the bandpass filter BPF, a color multiplex carrier wave with a specific repetition frequency is output depending on the amplitude and amplitude depending on the signal.
The phase modulated modulated wave Sc is output and sent to the output terminal 7.

The delay circuit DL1 to which the luminance signal Sy is supplied as described above outputs the delayed luminance signal Syd{5th
b reference}, and give it to the subtractor SUB as the minuend signal, and also
SUB contains the luminance signal Sy as a subtraction signal {a in Figure 5
reference} is supplied, the subtracter SUB outputs the edge signal (Syd-Sy) of the luminance signal as shown in c in Figure 5 and sends it to the control signal generation circuit.
Supply to CSG.

In the control signal generation circuit CSG described above, based on the edge signal (Syd−Sy) given to it,
A control signal Sp in a predetermined signal form {d in FIG. 5} is generated and supplied to the deflection circuit DEF. The signal format is suitable for correcting phase distortion.

The deflection circuit DEF, to which the control signal Sp generated from the control signal generation circuit CSG described above is applied, applies the deflection voltage supplied to the deflection electrode of the image pickup tube 2 to the edge of the previous luminance signal by approximately one horizontal scanning period. The deflection of the electron beam of the image pickup tube is controlled by the control signal obtained based on the signal, and the deflection of the electron beam of the image pickup tube is controlled to correspond to the charge pattern in the photoelectric conversion section of the image pickup tube. Changes in scanning speed occurring in the scanning electron beam are avoided, and as a result, time axis variations occurring in the color multiplexed signal are corrected.

(Effects of the Invention) As is clear from the above detailed explanation, the color imaging device of the present invention uses a color separation striped filter consisting of a predetermined arrangement of a plurality of types of color stripes at the photoelectric conversion section of the image pickup tube. In a color imaging device, the color imaging device is provided in an optical path up to and capable of generating a color multiplexed signal, and means for obtaining an edge signal thereof from a luminance signal obtained based on the color multiplexed signal; The time axis fluctuations that occur in the color multiplexed signal due to changes in the scanning speed that occur in the scanning electron beam in response to the charge pattern in the photoelectric conversion section of the image pickup tube are
According to the color imaging device of the present invention, correction means is provided based on the control signal obtained based on the edge signal of the luminance signal. By using a control signal, it is possible to easily correct the time-axis fluctuation that occurs in the color multiplexed signal due to the change in scanning speed that occurs in the scanning electron beam in correspondence with the charge pattern in the photoelectric conversion section of the image pickup tube. Therefore, according to the present invention, a color video signal from which a reproduced image with good image quality can be obtained can be easily generated.

[Brief explanation of the drawing]

1 to 4 are block diagrams of embodiments of the color imaging apparatus of the present invention, and FIGS. 5 and 6 are explanatory waveform diagrams. O... Imaging object, 1... Imaging lens, 2... Image pickup tube, 3... Deflection yoke, 4... Photoelectric conversion section of image pickup tube (target having a photoelectric conversion surface), F... Color separation striped filter, 5... Image pickup tube front plate, PrA... preamplifier, LPF, LPFl... low pass filter (low pass filter), BPF... band pass filter (band pass filter),
DL1, DL2, DL3...Delay circuit, VDL, VDL
1, VDL2...variable delay circuit, SUB...subtractor,
CSG...Control signal generation circuit, MA...Storage device, CD
…Carrier start position detection circuit, FMDC…FM
Detection comparison circuit, SSG...Reference signal generator SSG,
SGDET1, SDET2...Synchronous detector, DEF...Deflection circuit.

Claims (1)

[Claims] 1. A color imaging device that is equipped with a color-separating striped filter consisting of a predetermined arrangement of multiple types of color stripes in the optical path up to the photoelectric conversion section of the image pickup tube, and is capable of generating color multiplexed signals. In the apparatus, means for obtaining an edge signal of a luminance signal obtained based on the color multiplexed signal, and a variable delay circuit whose delay time is controlled by a control signal obtained based on the edge signal of the luminance signal. and a correction means configured to correct time axis fluctuations occurring in the color multiplexed signal due to changes in scanning speed occurring in the scanning electron beam corresponding to the charge pattern in the photoelectric conversion section of the image pickup tube. Characteristic color imaging device.