JPS6188685A - Color image pickup device - Google Patents

Abstract

PURPOSE:To to obtain a reproduced picture with excellent picture quality by correcting time axis fluctuation cause in a color multiplex signal due to the change in scanning speed produced in a scanning electron beam by means of a control signal obtained based on an edge signal of a luminance signal. CONSTITUTION:An output signal from the image pickup tube 2 is inputted to low and band pass filters LPF, BPF via a preamplifier PrA. A luminance signal Sy is outputted from the low pass filter LPF and transmitted to a terminal 6 and a delay circuit DL1 and a subtractor SUB output an edge signal (syd-sy) of the luminance signal. The edge signal is inputted to a control signal generating circuit CSG to convert a modulated wave Sc outputted from the band pass filter BPF to a control signal Sp of a prescribed signal form.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a color television (hereinafter abbreviated as TV) imaging device, in particular, to a color separation striped filter up to a photoelectric conversion surface of an imaging tube. The present invention relates to a color imaging device configured to be provided in an optical path.

(Prior art) A color-separated M13 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 photographed is provided on the photoelectric conversion surface of the image pickup tube. Various types of color systems 416 and 416 that generate color multiplexed signals have been known.

(Problems to be Solved by the Invention) By the way, there is a color imaging system in which a color separation striped filter is provided in the optical path up to the photoelectric conversion surface of the m-picture tube to generate a color multiplexed signal from the picture tube. In the device, 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, and as a result, the frequency of the color multiplexed signal output from the image pickup tube changes. Color errors occur in the image.

Since the speed of the electron beam scanning the photoelectric conversion surface of the image pickup tube described above changes depending on the charge pattern on the photoelectric conversion surface, the color multiplexed signal output from the image pickup tube The frequency of the photoelectric conversion surface changes depending on the pattern of charges on the photoelectric conversion surface of the optical image pickup tube. Color shift occurs in the upper part where the amount of charge changes suddenly.

FIG. 6 is a time to explain 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 given to the photoelectric conversion surface T consists of an area shown as black and an area shown as white.

The optical image given to the photoelectric conversion surface T in the image pickup tube is
If it were as shown in (a) of the figure, the charge pattern on the photoelectric conversion surface T of the image pickup tube would correspond to the optical image given to it,
The potential of the surface on which the scanning electron beam impinges is low in the part corresponding to the black area in the optical image applied to the photoelectric conversion surface T of the image pickup tube; The speed of the electron beam that scans the photoelectric conversion surface T of the image pickup tube changes from the area where the potential of the photoelectric conversion surface T of the image pickup tube is low to the area where it is high, because the potential of the electron beam is high in the portion corresponding to the white area in the optical image. In other words, in the part where the light image applied to the photoelectric conversion surface T of the image pickup tube changes from a black area to a white area, the photoelectric conversion rate of the image pickup tube is faster. It becomes slower in the part where the potential of the surface T changes from a high part to a low 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 white area to a black area. .

Therefore, the color multiplexed signal output from the image pickup tube is
As shown in (b) of the figure, in the part of the optical image applied to the photoelectric conversion surface T of the image pickup tube that changes from a black area to a white area, the phase advances, and contrary to the above, In the part of the optical image applied to the photoelectric conversion surface T of the image pickup tube that changes from a white area to a black area, the phase is delayed, and therefore the brightness in the reproduced image changes. Color shift occurs at the border.

(Means for Solving the Problems) The present invention includes a color separation cotton-like filter having 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 signal, there is provided a means for obtaining an edge signal from a luminance number 4B obtained based on the color multiplexed signal, and a means for obtaining an edge signal thereof from a luminance number 4B obtained based on the color multiplexed signal, and a charge pattern in a photoelectric conversion section of an image pickup tube. Correspondingly, a color imaging device comprising means for correcting a time axis variation occurring in the color multiplexed signal due to a change in the scanning speed occurring in the scanning electron beam by 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.

□Figures 1 to 4 are block diagrams of different embodiments of the color imaging device of the present invention. The same drawing numbers are given.

In the figure, 0 is the object to be imaged, 1 is the imaging lens, 2 is the imaging tube, 3 is the deflection yoke, and 4 is the light i! of the imaging tube. Conversion unit (target with photoelectric conversion surface), F is a color separation striped filter Jl'J5 is the front plate of the image pickup tube, PrA is a preamplifier, L
PF is a low-pass filter (low-pass filter), BPF is a band-pass filter (bandpass filter), and the optical image of the object to be imaged is transmitted to the image pickup tube 2 via the color separation striped filter F. The image pickup tube output signal (color multiplexed signal) is output.

The signal form of the color multiplexed signal outputted from the image pickup tube 2 depends on the configuration of 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, it differs depending on whether it is used.

In FIG. 1, the output signal from the image pickup tube 2 is amplified by a preamplifier PrA, and then given to a low-pass filter LPF and a bandpass filter BPF.
The Ii1 degree signal sy is output and sent to the terminal 6, and is also supplied to the delay circuit DLI and the subtracter SOB. Further, the bandpass filter BI'F outputs a modulated wave Sc in which a color multiplexed carrier wave having a specific green return frequency is amplitude-two-phase modulated by a signal, and the modulated wave Sc is outputted via a delay circuit DL2 provided as necessary. The signal is supplied to the variable delay circuit VDL.

The delay circuit DLI, to which the luminance signal Sy output from the low-pass filter LPF is supplied as described above, outputs the delayed luminance signal Syd (the second (See (b) in Figure 5)
It is given to the subtractor SOB as the minuend signal.

Furthermore, since the subtractor SOB is supplied with the luminance signal Sy (see (a) in Figure 5) as a subtraction signal, the subtracter SOB outputs a luminance signal as shown in (c) in Figure 5. It outputs an edge signal (SyJ-5y) and supplies it to the control signal generation circuit C3G.

The control signal generating circuit C5G described above generates a control signal Sp ((d) in FIG. 5) in a predetermined signal form based on the edge signal (Sya-5y,) applied thereto, and transmits it with a variable delay. The control signal Sp, which is supplied to the circuit VDL and is generated by the control signal generation circuit C5G described above, is
The signal format is suitable for correcting the phase distortion of the image pickup tube output signal. In addition, a luminance signal is also supplied to the control signal generation circuit C5G through a path as shown by the dotted line in the figure, and phase distortion that occurs due to fluctuations in the signal level of the luminance signal is also corrected. It is also possible to generate such a control signal from the control signal generation circuit C5G.

The variable delay circuit VDL, to which the control signal Sp generated from the control signal generation circuit C5G described above is applied, responds to the color multiplexed signal as shown in FIG. 5(e) input thereto. The phase of the modulated wave Sc is changed by the control signal Sp described above, and a color multiplexed signal is generated due to a change in the scanning speed that occurs in the scanning electron beam in response to the charge pattern in the photoelectric conversion section of the J:1fUi tube. This allows timetable fluctuations to be corrected.

The time period Δt2 shown in FIG. This time delay ΔL2 is a time delay given to the modulated wave Sc in the color multiplexed signal in order to ensure that the phase correction operation of the modulated wave Sc in the color multiplexed signal is performed in a good condition. 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
The modulated wave Sc in the color multiplexed signal outputted from the variable delay circuit VDL to the output terminal 7 undergoes predetermined signal processing in a subsequent color signal processing circuit (not shown), and is then targeted. It is made into a color video signal according to the TV system. The color imaging device shown in FIG.
When configured according to the so-called step energy one-way system, the signal output from the output terminal 7 shown in FIG.
The signal processing may be performed by applying the signal to a color signal demodulation circuit shown in Japanese Patent Publication No. 5-33233, Japanese Patent Publication No. 5-35550, and the like.

Next, the embodiment shown in FIGS. 2 and 3 will be described. FIGS. 2 and 3 show a color imaging device as disclosed in FIG. each of the plurality of colors, such that the phase of the fundamental wave component of the image pickup tube output signal, which is determined in correspondence with the green pattern of a specific array pattern, changes depending on the color of light. A color-separated striped filter, in which the colors of the strips are set, is provided in the optical path to the photoelectric conversion section of the image pickup tube, and the optical image of the object to be imaged passes through the color-separated striped filter to the photoelectric converter of the image pickup tube. The converting section is provided with a configuration that allows the image to be captured, and a storage device that can arbitrarily store an information signal corresponding to at least one frame period of the output signal from the image pickup tube. Any specific color is imaged in advance, and an information signal corresponding to at least one frame period of the image pickup tube output signal is stored in the storage device, and the information signal stored in the storage device is In a color imaging device, a reference wave for color signal demodulation is obtained based on the reference wave, and a predetermined color signal is demodulated from the output signal of the image pickup tube by synchronous detection or the like. The time axis of one of the two signals, the information signal obtained by reading and the output signal of the image pickup tube, with one signal as a reference and the change mode of the other signal on the time axis as a reference. This is an embodiment in which the present invention is applied to a color imaging device provided with means for controlling to match the above-mentioned change mode.

In Figures 2 and 3, MTX is a matrix circuit, 5t)ETI, 5DET2 are synchronous detectors, HA 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. and
The details of the configuration and operation of the circuit layout consisting of these components are described in the above-mentioned Japanese Patent Application Laid-Open No. 59-1533.
It is advisable to refer to the contents of Publication No. 92.

Storage device HA shown in FIGS. 2 and 3 above
is at least one frame of the imaging tube obtained by imaging an arbitrary specific color among the color strips constituting the color-separated Hfa-like filter F, before the color imaging device starts color imaging. The information signal corresponding to one frame period is stored, and when the color imaging device starts capturing, the information signal in which the color image is stored can be sent out as a continuous signal on the time axis. The memory device M used is one that can perform various operations.
In A, ADC is an analog-to-digital converter, DM is a digital memory, DAC is a digital-to-analog converter, 0
3Ca is an address signal generator, and 05Cc is a clock signal generator.

Further, the carrier start position detection circuit (D) may be configured to have a function of generating a signal corresponding to the rising point of the fundamental wave component of the color multiplexed carrier wave in the output signal of the image pickup tube. This can be constructed using, for example, a programmable multi-by-break and a differentiating circuit.

The FM detection comparison circuit FMDC has the function of outputting a signal indicating the polarity and magnitude according to the frequency difference between two signals. It can be constructed by a discriminator and a ratio device that compares the output signals from the frequency discriminator.

Furthermore, the reference signal generator SSG is connected to the memory device MA described above.
Based on the signal sent from the synchronous detectors 5DEn, 5
It generates unified reference signals each having a predetermined phase required during demodulation of the color signal in opr2 and supplies them to the synchronous detectors 5DETI, 5l) ET2, which includes, for example, a phase-locked loop. It may be configured by a synchronous Am unit configured with a phase shifter and a phase shifter.

In FIGS. 2 and 3, the storage device HA stores an image obtained by imaging an arbitrary specific color (the color of an arbitrary specific color strip in a color separation flocculent filter) prior to capturing an image of an object to be imaged. An information signal corresponding to at least one frame period of the fundamental component of the color multicarrier (the signal component passed through the bandpass filter 813F) in the output signal of the tube must be stored.

This is done by operating a predetermined operation button on an operation section (not shown) provided on the color imaging device.

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, light of a specific color is automatically applied to the image pickup tube, and the storage device HA is set to the storage mode, so that the signal component of the output signal of the image pickup tube 2 that has passed through the bandpass filter 11PF is digitalized. stored in memory.

The analog-to-digital converter ADC performs AD conversion using a sampling pulse given from a pulse source (not shown) and supplies a digital signal to a digital memory, and the digital memory DM stores the supplied digital signal. It goes without saying that the sequential storage of digital signals in the digital memory DM is performed by the address signal generated by the address signal generator 05Ca. It is operated by a clock signal generated by 05Ca.

When the storage device is put into the storage mode and the information signal corresponding to one frame period has been stored in the digital memory DH, the storage device MA is put into the read mode and the information signal from the digital memory DM is stored. The information signal stored corresponding to one frame period is read out in green, converted to an analog signal by the digital-to-analog converter DAC, and given to the reference (i-number generator SSG) to generate the basic signal. Vessel S
The SG generates reference signals for synchronous detection (for color signal demodulation) each having a predetermined phase based on the signal applied to the iL.

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 reference signal created based on the information signal read out from the storage device HA as described above. However, the deflection circuit and deflection yoke in color imaging devices are
Their stability is not sufficient, and as a result, the scanning mode of the electron beam changes due to external magnetic fields, and the scanning mode of the electron beam 11 described above also changes due to other causes. Even if an information signal stored in advance in the storage device MA is read out and color demodulation is performed using a reference signal created based on the information signal, it is not always possible to obtain a good color signal. Therefore, in the color imaging apparatus shown in FIGS. 2 and 3, the manner of change on the time axis of the information signal read from the storage device HA is the same as that of the output signal from the image pickup tube on the time axis. The carrier start position detection circuit C1l FM detection comparison circuit FMD
The main components such as the C1 storage device MA, the basic signal generator SSG, and the synchronous detectors 5DETI and 5DET2 are made to operate.

Here, in the circuit arrangement shown in FIG. 2, a delay circuit DLI, a subtracter SOB, a control signal generation circuit CS
G, operation of the circuit arrangement with components such as the variable delay circuit VDL omitted, and the circuit arrangement shown in FIG. The operation of the circuit arrangement with components such as circuits VDLI and VDL2 omitted will be described.

When the device is in the imaging mode and information signals are read out from the storage device MA, the bandpass filter B
The output signal from PF is synchronous detector 5DET1.5DET
2, carrier star 1 - position detection circuit CI) and FM
When applied to the detection comparison circuit FMDC, the storage device HA
A reference signal generated by the basic signal generator SSG based on the signal read from the digital memory DA of It is given to the detection comparison circuit FMDC, etc. In the FM detection comparison circuit FMDC, the 2 signals given to it,
That is, it outputs 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, and supplies it to the clock signal generator 03Cc in the storage device. , the period of the clock signal generated by the clock signal generator 05Cc is changed in such a direction that the frequency difference between the two signals described above becomes significant. Further, the gear 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 05C3 in the storage device HA at the time when the B11 blanking period ends and the carrier appears. Reset the fidget and ensure correct centering movement.

In addition, by changing the period of the clock signal of the clock signal generator 05Cc by the output (No. 1) of the FM detection comparison circuit FMDC, the reference signal supplied from the reference signal generator SSG to the synchronous detectors 5DETI and 5DET2 becomes The output signal of the bandpass filter BPF exhibits a time axis variation similar to that of the output signal of the synchronous detector 5DET1.
The 5DET2 always outputs the correct color signal and operates constantly.

However, depending on the operation described in "-" in the JLR component described in "1", the color multiplexed signal is Since the resulting time axis fluctuations cannot be well corrected, in the color imaging device of the present invention, 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 imaging tube causes the color multiplexed signal to be corrected. In order to properly correct the occurring time axis fluctuations, the embodiment device shown in the second figure uses a bandpass filter BPF.
A variable delay circuit VDL is provided in the signal transmission path from to the synchronous detectors 5DETI and 5DET2, and the amplifier Pr
A luminance signal Sy obtained from the output signal of A through a low-pass filter LPF is supplied to a delay circuit DLI and a subtraction circuit SOB to generate an edge signal, and the edge signal is supplied to a control signal generation circuit C5G. A control signal is generated 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. In the device, variable delay circuits vbL1 . Install vDL2,
The luminance signal sy obtained from the amplified 1iiPrA (7) output signal through the low-pass filter LPF is transferred to the delay circuit D.
LI and the subtraction circuit SUB so that an edge signal is generated, and the edge signal is sent to the control signal generation circuit C3.
G, a control signal is generated based on the edge signal, and the time delay of the variable delay circuits VDLI and VDL2 is controlled by the control signal generated from the control signal generation circuit SSG.

Variable delay circuit Vl)L, delay circuit DLL, subtraction circuit SOB, control signal generation circuit CS in the circuit arrangement shown in the second diagram
The operation of the constituent parts of each part such as G is the same as that of the variable delay circuit VDL, delay circuit DI, 1, subtraction circuit SOB, control signal generation circuit CSG, etc. in the circuit layout explained with reference to FIG. The operation is the same as that of the variable delay circuits VDLl and VDL in the circuit arrangement shown in FIG.
2. The effect of correcting the time axis fluctuation of the color multiplexed signal obtained by the operation of each component such as the delay circuit, DLl, subtraction circuit SUB, and control signal generation circuit C5G has already been described with reference to FIG. This is similar to the effect of correcting time axis fluctuations of the color multiplexed signal obtained by circuit operation.

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 in the circuit arrangement shown in the third diagram, the time axis of the color multiplexed signal itself is changed by the control signal. 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 it is in a state of

In addition, in FIGS. 2 and 3, the matrix i path MT
Needless to say, predetermined primary color signals are outputted from X to terminals 8 to 10, respectively (Japanese Patent Application Laid-open No. 59-1999)
153392).

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-separating cotton-like 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 structure). A modulated wave in which a DC component and a color multiplex carrier wave having a specific repetition frequency is amplitude-double-phase modulated by the signal is supplied from the image pickup tube 2 to the photoelectric conversion unit 4 of ゛) which is said to be of the embodiment An output signal (color multiplexed signal) of the image pickup tube containing the following is output.

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

The delay circuit DL3 described above is one that gives the luminance signal a time delay of a time (IH-Δt), which is a slight time Δt shorter than one horizontal scanning period (IH). The luminance signal output from the delay circuit DL3 is supplied to the delay circuit DLI and the subtracter SOB.

Further, the bandpass filter BPF outputs a modulated wave Sc in which a color multiplex carrier having a specific green return frequency is amplitude-9-phase modulated by a signal and sent to an output terminal 7.

The delay circuit DLI is supplied with the luminance signal Sy as described above.
is the delayed luminance signal Syd in a state where a slight time delay Δt1 is given to the luminance signal sy described above ((b in FIG. 5))
) and gives it to the subtractor SOB as a subtraction signal, and the luminance signal Sy (see (a) in Figure 5) is supplied as a subtraction signal to the above-mentioned MLr unit SUB. , from the subtractor SUB, the luminance (edge of No. 7J (No. m (Sy, 1I-3)
y) and supplies it to the control signal generation circuits C and SG.

The control signal generation circuit C5G described above generates a control signal Sp ((d) in FIG. 5) in a predetermined signal form based on the edge signals (Sy, ISy) applied thereto, and then The control signal Sp, which is supplied to the deflection circuit DEF and generated by the above-described signal generation circuit C5G, is in a signal form suitable for correcting the phase distortion of the image pickup tube output signal.

The deflection circuit DEF, to which the control signal Sp generated from the control signal generation circuit C5G described above is applied, supplies the deflection voltage to the deflection electrode of the image pickup tube 2 by approximately one horizontal scanning period before the edge of the luminance signal. 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 in accordance with 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, resulting in time tiii! in the color multiplexed signal! This is done so that the fluctuations 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 several types of color stripes in the photoelectric conversion section of the imaging 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 fluctuation that occurs in the color multiplexed signal due to the change in scanning speed that occurs in the scanning electron beam corresponding to the charge pattern in the photoelectric conversion section of the image pickup tube is corrected by the control signal obtained based on the edge signal of the luminance signal described above. According to the color imaging device of the present invention, the control signal obtained based on the edge signal obtained from the bright 23 signal can be used to determine the charge pattern in the photoelectric conversion section of the image pickup tube. Correspondingly, it is possible to easily correct 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, so the present invention can easily correct color images that can reproduce reproduced images with good image quality. Signals can be easily generated.

[Brief explanation of drawings]

1 to 4 are block diagrams of embodiments of the color imaging device of the present invention, and FIGS. 5 and 6 are explanatory waveform diagrams.

Claims (1)

[Claims] A color imaging device that is equipped with a color separation striped filter consisting of a predetermined arrangement of a plurality of types of color stripes in an optical path up to a photoelectric conversion section of an image pickup tube, and is capable of generating a color multiplexed signal. In this method, color multiplexing is performed by means of obtaining an edge signal from a luminance signal obtained based on the color multiplexed signal, and a change in scanning speed occurring in a scanning electron beam corresponding to a charge pattern in a photoelectric conversion section of an image pickup tube. and means for correcting time axis fluctuations occurring in the brightness signal using a control signal obtained based on the edge signal of the brightness signal.