JPH09284789A - Synchronization system for image signal processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synchronization system for an image signal processing system from which a High Vision system image signal is outputted by employing a solid-state image pickup element for a standard television system image signal with a simple configuration. SOLUTION: In this system, no PLL circuit is used and no phase comparator is used because an image pickup device and an image signal processing unit are synchronized only with transmission of a frame pulse, and a single crystal oscillator 31 is adopted for a voltage-controlled crystal oscillator. When a changeover switch 35 is used to select an output oscillation signal from an NTSC crystal oscillator 34, the image pickup device and the image signal processing unit are operated by the same frame frequency of nearly 29.97Hz. In the case that an output oscillation signal from a High Vision crystal oscillator 33 is selected, an error of nearly a half of a line of the NTSC system is produced for a frame period. Various timing signal generator 32 for the image pickup device is reset by the frame period of the image signal processing unit regardless of the error. A reset timing is taken within a vertical blanking period of the image pickup device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronization system of an image signal processing system, and in particular, it utilizes a solid-state image pickup device for image signals of a standard television system such as NTSC system or PAL system to obtain a high definition system such as a high definition system. The present invention relates to a synchronization method for synchronizing timing signals in an image signal processing system that obtains the image signal.

[0002]

2. Description of the Related Art In an image pickup apparatus for obtaining an image signal of a high-definition television system which is a high definition television system as compared with an image signal of a standard television system such as an NTSC system or a PAL system, a timing signal for obtaining an image signal of a high-vision system is usually used The generator only needs to generate a timing signal based on the high-definition method. However, the dedicated image pickup apparatus is required to have a high signal processing speed, the power consumption is high, and the peripheral devices used are also required to have a high degree of accuracy. Therefore, the present applicant has previously proposed an image pickup device and an image signal processing device that obtain a high-definition image signal by using a solid-state image pickup device for a standard television image signal (for example, Japanese Patent Application No. 5-152850). , Japanese Patent Application No. 6-
257583).

The image pickup apparatus and the image signal processing apparatus proposed by the present applicant constitute an image signal processing system as shown in the block diagram of FIG. In the figure, incident light is made incident on the image pickup apparatus 1 proposed by the applicant of the present invention, which is composed of a color separation optical system and a solid-state image pickup device having a resolution of a standard television system, and here, the first timing signal generator 2 After being converted into a plurality of image pickup signals which are electric signals based on the timing signal from, the signal is supplied to the image signal processing device 4 proposed by the applicant of the present invention through the buffer circuit 3, and here the second timing is obtained. Based on the timing signal from the signal generator 5, frame synthesis, addition of a vertical high frequency signal to the luminance signal obtained by the matrix circuit, and other signal processing are performed and converted into a high definition image signal. Is output.

The first timing signal generator 2 receives the timing signal from the second timing signal generator 5 and generates a first timing signal in synchronization with it.
Further, the buffer circuit 3 writes the image pickup signal based on the first timing signal from the first timing signal generator 2 and outputs the image pickup signal based on the second timing signal from the second timing signal generator 5. read out.

Further, in this system, the image signal processing device 4 is configured to switch between a standard television system image signal and a high-vision system image signal so that the standard television system image signal and the high-vision system image signal are switched. An image signal processing system capable of selectively obtaining a system image signal can be realized.

In the image signal processing system using the image pickup apparatus and the image signal processing apparatus proposed by the present applicant,
When the system shown in FIG. 4 is constructed, the first timing signal generator 2 is for standard television system image signals because the imaging device 1 uses a solid-state image sensor of standard television system resolution. On the other hand, the second timing signal generator 5 generates the timing signal for the high-definition image signal in order to obtain the high-definition image signal, but in order to obtain the high-definition image signal from the output image pickup signal of the image pickup apparatus 1. The above timing signal generators 2 and 5 must be synchronized at the frame frequency.

Further, the timing signal generators 2 and 5 are
In some cases, the reference clock cannot be shared. From the above points, in order to match the output image signal with the standard of the high-definition system, the timing signal generator 5 needs a circuit for generating a clock with high frequency accuracy such as a crystal oscillator. Therefore, the clock of the timing signal generator 2 must be generated by a phase locked loop (PLL) circuit which is synchronized with a frame as shown in FIG.

In FIG. 5, various timing signal generators 11 for an image pickup device, a phase comparator 12, and a voltage controlled crystal oscillator 13 constitute the first timing signal generator 2, and a crystal oscillator 14 and The various timing signal generators 15 for the image signal processing device constitute the second timing signal generator 5.

In this conventional synchronization system, the crystal oscillator 14
The high-precision oscillating frequency generated and output from the above is supplied to various timing signal generators 15 for the image signal processing device, where it is converted into various timing signals required for the high-definition system, and then the image signal processing of FIG. Output to device 4,
Further, the frame pulse among them is supplied to the phase comparator 12, where the various timing signal generators 1 for the image pickup apparatus are provided.
The phase is compared with the frame pulse from 1 and converted into a phase error signal according to their phase difference.

This phase error signal is supplied to the voltage-controlled crystal oscillator 13 as a control voltage to variably control its output oscillation frequency. The output oscillation frequency of the voltage controlled crystal oscillator 13 is determined by the various timing signal generators 1 for the image pickup apparatus.
1, and is generated and output to various timing signals necessary for the image pickup apparatus 1 of FIG. 4, and the frame pulse among them is fed back to the phase comparator 12.

Further, the applicant of the present invention has previously described the image signal processing device 4
Image signal processing capable of selectively obtaining the standard television system image signal and the high-definition system image signal by arranging the part of the part for switching between the standard television system image signal and the high-vision system image signal A system is disclosed (for example, SHINOZAKI Shun et al., "Development of a consumer-use four-panel high-definition camera", Journal of the Television Society, Vol. 50, No. 2 (1996), pp.
274-280).

That is, in the image pickup apparatus proposed above, a charge coupled device (CCD) for image stabilization for the PAL system is used as the solid-state image pickup element, and the circuit of the image signal processing apparatus is largely digitized. In addition to imaging as a high-definition camera, N to obtain NTSC image signals
TSC mode is possible.

Here, the image pickup device according to the above-mentioned proposal prepares first and second CCDs for green light, which are vertically shifted from each other by one pixel pitch and horizontally shifted from each other by 1/2 pixel pitch. In addition, a total of four Cs, one each for the blue light and one for the red light, shifted in the vertical direction by 1/2 pixel pitch with respect to one of those CCDs, are provided.
In the case of the image pickup device having a CD, in the NTSC mode, the driving method of the CCD is set to a normal field accumulation mode in which adjacent lines are mixed and read out, and the green light image pickup signal (G) output from each of the first and second CCDs. (Signal) is averaged into one G signal, and various interpolation processing and double speed conversion processing which are performed in the high-definition signal processing are not performed, so that the image is captured in the NTSC mode. Note that there are two types of aspect ratios of image signals obtained by imaging in the NTSC mode: 16: 9 and 4: 3.

When the synchronization system having the configuration shown in FIG. 4 is applied to the image signal processing system capable of selectively obtaining the standard television system image signal and the high-definition system image signal, the PAL system and the high-definition system are different from each other. Since the frame frequency is the same 30Hz, there is no problem, but NT
In SC and HDTV systems, the NTSC frame frequency is 30H, which is the HDTV frame frequency.
Since it is 29.97 Hz, which is different from z, the voltage controlled crystal oscillator cannot cope with the frequency of this frame frequency difference.

For this reason, the synchronization system applied to the image signal processing system capable of selectively obtaining the NTSC system image signal and the high-definition system image signal has conventionally been constructed as shown in FIG. 5, the same components as those of FIG. 5 are denoted by the same reference numerals, and the description thereof will be omitted. In FIG. 6, the second timing signal generator 5 selects one of the output oscillation signals of the high-definition crystal oscillator 17 and the NTSC oscillator 18 with the changeover switch 19 and supplies it to the various timing signal generators 15 for the image signal processing device. It is configured to do.

Further, the first timing signal generator 2 supplies the output phase error signal of the phase comparator 12 to the high-definition voltage-controlled crystal oscillator 20 and the NTSC voltage-controlled crystal oscillator 21 to output their output oscillation frequencies. Variably controlled so that one of these output oscillation frequencies
And is supplied to the various timing signal generators 11 for the image pickup apparatus. Changeover switches 19 and 22
The image signal system to be obtained is a high-definition system or NT
Switching control is performed based on a signal indicating the SC system.

[0017]

In the above-mentioned conventional synchronization method, when a high-definition image signal is obtained, a timing signal generator having the configuration shown in FIG. 5 is required.
There is a problem that the configuration is complicated and expensive. Also, NT
In the image signal processing system capable of selectively obtaining the SC system image signal and the high definition system image signal,
Since the timing signal generator having the configuration shown in FIG. 6 is required, one more crystal oscillator, one voltage control type crystal oscillator, and two changeover switches are required as compared with FIG. 5, which further complicates the configuration. It becomes expensive.

The present invention has been made in view of the above points,
An object of the present invention is to provide a synchronization system of an image signal processing system capable of outputting at least a high-definition system image signal by using a solid-state imaging device for standard television system image signal with a simple configuration.

[0019]

In order to achieve the above object, the present invention drives an image pickup apparatus comprising a color separation optical system and a plurality of standard television system image signal solid-state image pickup elements, and the image pickup apparatus. A high-definition television including a first timing signal generator for generating various timing signals, and a reference frequency and a line frequency different from the reference frequency and the line frequency in the output timing signal of the first timing signal generator. A second timing signal generator for generating various timing signals of the John system, and an output imaging signal of the imaging device are written based on the output timing signal of the first timing signal generator, and the second timing signal generator The buffer circuit read out based on the output timing signal and the image pickup signal read out from the buffer circuit are input to the second timing unit. An image signal processing system comprising an image signal processing device for generating and outputting an image signal of at least a high definition television system based on an output timing signal of the signal generator and an input image pickup signal, the second timing signal generator 1st by the frame pulse output from
The timing signal generator is reset at the frame cycle.

In the present invention, the first timing signal generator does not have a PLL circuit configuration for generating a timing signal synchronized with the frame pulse from the second timing generator, but a frame pulse from the second timing signal generator. It can be configured by a signal generator that is reset by.

Further, the present invention provides various timing signals of a high definition television system including a reference frequency and a line frequency different from the reference frequency and the line frequency in the output timing signal of the second timing signal generator. And a second timing signal generator that selectively generates and outputs one of the various timing signals of the same standard television system as the output timing signal of the first timing signal generator, and the image signal processing device operates from the buffer circuit. One of a high-definition television system image signal and a standard television system image signal instructed by an external instruction signal is generated based on the read image signal and the output timing signal of the second timing signal generator. The frame pulse output from the second timing signal generator of the image signal processing system configured to output Ri is obtained by a structure for resetting the first timing signal generator with a frame period.

According to the present invention, since the first timing signal generator is reset by the frame pulse from the second timing signal generator, the image signal processing apparatus has the image signal of the high definition television system and the standard television. A PLL provided with two kinds of oscillators for switching and generating timing signals dedicated to respective television systems synchronized with the frame pulse from the second timing generator according to which of the image signals of the respective systems is to be generated and output. The circuit configuration can be eliminated.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a main part of a synchronization system of an image signal processing system according to the present invention. As shown in the figure, in the present embodiment, the first timing signal generator 2 of FIG. 4 in the image signal processing system capable of selectively obtaining an NTSC system image signal and a high-definition system image signal, The second timing signal generator 5 shown in FIG. 4 is composed of a crystal oscillator 31 for the image pickup device and various timing signal generators 32 for the image pickup device.
HDTV crystal oscillator 33, NTSC
It comprises a crystal oscillator 34, a changeover switch 35, and various timing signal generators 36 for the image signal processing device.

To explain the operation of this embodiment, the changeover switch 35 is switch-controlled on the basis of a signal instructing whether the image signal system to be obtained is the high-definition system or the NTSC system to obtain the high-definition system image signal. In this case, the output oscillation signal (reference frequency) of the high-definition crystal oscillator 33 is selected, and when the NTSC system image signal is obtained, the output oscillation signal (reference frequency) of the NTSC crystal oscillator 34 is selected.

The oscillation signal selected by the changeover switch 35 is the various timing signal generators 3 for the image signal processing device.
6 and is converted into various timing signals (reference frequency signal, frame pulse, line pulse, etc.) according to the image signal system instructed here, and then output terminal 38.
While being supplied to the image signal processing device (not shown) proposed by the applicant of the present invention, the frame pulse therein is supplied to various timing signal generators 32 for the image pickup device.

Various timing signal generators 32 for the image pickup device
Is reset at the frame cycle by the input frame pulse, and the crystal oscillator 3 for the NTSC solid-state image sensor is
Various timing signals necessary for the image pickup apparatus proposed by the applicant of the present application are generated based on the reference oscillation signal for the NTSC system output from 1. The various timing signals generated by the various timing signal generators 32 for the image pickup device are input to the image pickup device (not shown) proposed by the applicant of the present application through the output terminal 37.

Here, as the image pickup device proposed by the present applicant, for example, the first and the first for green light are vertically shifted by 1 pixel pitch and horizontally shifted by 1/2 pixel pitch. While preparing the solid-state image sensor of No. 2,
1/2 in the direction perpendicular to one of the solid-state image sensors
Third one for blue light and one for red light with pixel pitch offset
Also, there is an image pickup apparatus having a total of four solid-state image pickup elements including a fourth solid-state image pickup element.

As the above-mentioned image signal processing device proposed by the present applicant when this image pickup device is used, the first and first image-synthesizing signals output from the third and fourth solid-state image pickup devices are frame-synthesized. 2 combining means, an extracting means for extracting the first and second high frequency signals in the vertical direction from the output frame combined signals of the first and second combining means, and the first to fourth solid-state imaging devices A matrix circuit that generates a color difference signal and first and second luminance signals based on the picked-up image pickup signals respectively, and a first luminance signal output from the matrix circuit with a first high-frequency signal from the extraction means. A third synthesizing means for synthesizing and a second synthesizing means for outputting the second
4th synthesizing means for synthesizing the second high frequency signal from the extracting means with the luminance signal of 1), and the 1st luminance signal output from the matrix circuit and the synthetic signal from the 3rd synthesizing means in one field. First selecting means for alternately selecting each for each field, and second selecting means for alternately selecting the second luminance signal output from the matrix circuit and the combined signal from the fourth combining means for each field. It is configured to have.

Further, as another example of the image pickup device, the pixel pitches are vertically shifted from each other by 1 pixel and the horizontal direction is 1 / pitch.
Two first and second solid-state image pickup devices for green light having a two-pixel pitch shift are prepared, and one of the solid-state image pickup devices for green light is vertically shifted by a half-pixel pitch, and There is an image pickup apparatus having a total of four solid-state image pickup devices, one each for red light and one for green light, which are vertically shifted from each other by one pixel pitch.

In the above-mentioned image signal processing apparatus proposed by the present applicant using the above-mentioned image pickup apparatus, the first and second synthesizing means are arranged in the same synthesizing circuit as the third and fourth solid-state image pickup elements. This is a configuration for combining output image pickup signals.

Further, as another example of the image pickup device, the pixel pitches are vertically shifted from each other by 1 pixel and the horizontal direction is 1 / pitch.
Two pieces of first and second solid-state image pickup elements for green light, which are shifted by 2 pixel pitch, are prepared, and one of them is vertically shifted by 1/2 pixel pitch from the solid-state image pickup element for green light to obtain a red color. There is an image pickup apparatus having a total of three solid-state image pickup elements in which a third solid-state image pickup element for both light and green light is arranged.

As the above-mentioned image signal processing device proposed by the applicant using the above-mentioned image pickup device, a first synthesizing means for synthesizing the image pickup signal output from the third solid-state image pickup device by frame, and a first synthesizing means. Extracting means for extracting the first and second high frequency signals in the vertical direction from the output frame combined signal of the combining means, and the first high frequency from the extracting means for the output image pickup signal of the first solid-state image pickup device. Second synthesizing means for synthesizing signals, third synthesizing means for synthesizing the second high-frequency signal from the extracting means with the output image pickup signal of the second solid-state image pickup element, and the first solid-state image pickup element Output signal from the second solid-state image sensor and the third combination unit. The second that alternately selects the signal and the signal for each field It is configured to have a-option means, and a matrix means for generating a luminance signal and color difference signal based on the output signal of the output image signal and the first and second selecting means of the third solid-state imaging device.

The above-described image signal processing device is configured to obtain a high-definition image signal, but if at least an NTSC image signal is selectively obtained in addition to this high-definition image signal, a circuit configuration for that is required. To do.

By the way, according to the embodiment shown in FIG. 1, as compared with the conventional synchronization system shown in FIG. 6, an imaging device and an image signal processing device are provided without using a PLL circuit and only by transmitting frame pulses. The phase comparator 12 can be omitted because the configuration is synchronized. Further, the voltage controlled crystal oscillator is also a simple crystal oscillator 31, and the number thereof is NT.
It is unified to one for SC.

Therefore, the changeover switch 35 causes the NTS
When the output oscillation signal of the C crystal oscillator 34 is selected, both the image pickup device and the image signal processing device operate at the same frame frequency of about 29.97 Hz, but the accuracy of the crystal oscillators 34 and 31 depends on the accuracy because the PLL circuit is not provided. , There are some errors in the frame cycle of each self-propelled.

When the output oscillation signal of the high-definition crystal oscillator 33 is selected by the change-over switch 35, the frame frequency of the image signal processing device is 30 Hz, so that the frame period is about half the line of the NTSC system. There is an error. In this embodiment, the various timing signal generators 32 for the image pickup device are reset at the frame cycle of the image signal processing device regardless of this error. However, it is a necessary condition that the reset position is within the vertical blanking of the imaging device. That is, the length of the signal in which the image portion is not read out from the solid-state image sensor is partially changed.

Even if the length of the signal in which the image portion is not read out from the solid-state image pickup device is partially changed as described above, the image signal processing system to which this embodiment is applied is as shown in FIG. Since the buffer circuit 3 is provided between 1 and the image signal processing device 4, there is no problem. This buffer circuit 3
For example, as shown in FIG. 2, it can be constituted by a field memory 43.

In FIG. 2, first and second timing signal generators 41 and 42 are circuits corresponding to the timing signal generators 2 and 5 shown in FIG. 4, and the first timing signal generator 41 is shown in FIG. A second timing signal generator 42, which is a circuit portion including a crystal oscillator 31 for the NTSC solid-state image sensor and various timing signal generators 32 for the image pickup apparatus.
Is a circuit unit including a high-definition crystal oscillator 33, an NTSC crystal oscillator 34, a changeover switch 35, and various timing signal generators 36 for the image signal processing device.

The field memory 43 is based on the write clock from the timing signal generator 41, and the image pickup device 1
Output image pickup signal is written into the timing signal generator 4
Based on the read clock from 2, the stored image pickup signal is read. Therefore, the image pickup signal of only the image portion from the image pickup apparatus 1 can be written in the field memory 43, so that the blanking portion may have any length.

FIG. 3 is a block diagram of another embodiment of the main part of the synchronization system of the image signal processing system according to the present invention. In the figure, the same components as those in FIG. 1 are denoted by the same reference numerals.
In this embodiment, the first timing signal generator 2 of FIG. 4 in the image signal processing system configured to obtain only the high-definition image signal from the image signal processing device is replaced with the crystal oscillator 51 and various timing signal generators for the imaging device. 32
And the second timing signal generator 5 of FIG.
As shown in FIG. 3, it comprises a crystal oscillator 52 and various timing signal generators 53 for the image signal processing device.

To explain the operation of this embodiment, the oscillation signal oscillated and output from the crystal oscillator 52 is supplied to various timing signal generators 53 for the image signal processing device, where it is converted into various high-definition timing signals. After being converted, it is supplied to the image signal processing device (not shown) proposed by the applicant of the present invention through the output terminal 54, while the frame pulse therein is various timing signal generators 32 for the image pickup device. Is supplied to.

Various timing signal generators 32 for the image pickup device
Is reset at the frame cycle by the input frame pulse and within the vertical blanking of the image pickup device, and based on the reference oscillation signal for the NTSC system or the HDTV system output from the crystal oscillator 51, Various timing signals necessary for the imaging device proposed by the present applicant are generated. The various timing signals generated by the various timing signal generators 32 for the image pickup device are input to the image pickup device (not shown) proposed by the applicant of the present application through the output terminal 37.

According to this embodiment, as compared with the conventional synchronization system shown in FIG. 5, a PLL circuit is not used and only the frame pulse is transmitted, so that the image pickup device and the image signal processing device are synchronized with each other. Therefore, the phase comparator 12 can be omitted. Further, the voltage-controlled crystal oscillator is also a simple crystal oscillator 51, and the number thereof is unified.

The present invention is not limited to the above-described embodiment, and for example, in the embodiment of FIG.
The NTSC solid-state image sensor crystal oscillator 31 may be a high-definition solid-state image sensor crystal oscillator. The NTSC crystal oscillator 34 may be a PAL crystal oscillator.

[0046]

As described above, according to the present invention,
Since the first timing generator that outputs the timing pulse for driving the imaging device is configured to be reset by the frame pulse from the second timing signal generator, the first timing signal generator causes the second timing signal generator to be reset. Can be configured with a single fixed oscillator and a single signal generator instead of the PLL circuit configuration that generates the timing signal synchronized with the frame pulse from the pulse generator, and the phase comparator and voltage controlled oscillator that configure the PLL circuit are unnecessary. Therefore, the circuit configuration can be simplified and the cost can be reduced.

Further, according to the present invention, when the image signal processing device selectively generates or outputs either the high definition television system image signal or the standard television system image signal in accordance with an external signal, Since it is possible to eliminate the need for a PLL circuit configuration including two types of oscillators that generate timing signals dedicated to each television system in synchronization with the frame pulse from the second timing generator, the circuit configuration is further simplified. It can be constructed at low cost.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a main part of a system of the present invention.

FIG. 2 is a block diagram showing an example of a buffer circuit together with peripheral circuits.

FIG. 3 is a block diagram of another embodiment of the main part of the system of the present invention.

FIG. 4 is a configuration diagram of an example of an image signal processing system to which the method of the present invention is applied.

FIG. 5 is a block diagram of an example of a main part of a conventional method.

FIG. 6 is a block diagram of another example of the main part of the conventional method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Imaging device 2, 5, 41, 42 Timing signal generator 3 Buffer circuit 4 Image signal processing device 31 NTSC solid-state image sensor crystal oscillator 32 Various imaging device timing signal generator 33 Hi-vision crystal oscillator 34 NTSC crystal oscillator 35 Changeover switch 36, 53 Various timing signal generators 37, 38, 54 for image signal processing device Timing signal output terminal 43 Field memory 51, 52 Crystal oscillator

Claims (5)

[Claims] 1. An image pickup device comprising a color separation optical system and a plurality of standard television system image signal solid-state image pickup devices; a first timing signal generator for generating various timing signals for driving the image pickup device; A second timing signal for generating various timing signals of a high definition television system including a reference frequency and a line frequency different from the reference frequency and the line frequency in the output timing signal of the first timing signal generator. A generator, and an image pickup signal output from the image pickup device is written based on an output timing signal from the first timing signal generator,
A buffer circuit read based on the output timing signal of the second timing signal generator, and an image pickup signal read from the buffer circuit is input, and the output timing signal of the second timing signal generator and the input image pickup An image signal processing system comprising an image signal processing device for generating and outputting an image signal of at least the high definition television system based on a signal, the frame pulse output from the second timing signal generator, 1. A synchronization method for an image signal processing system, wherein the timing signal generator 1 is reset at a frame cycle. 2. The first timing signal generator includes a first oscillator that outputs a first signal in fixed oscillation, and the first timing signal generator.
A first signal generator for generating various timing signals for the image pickup device based on the signal of No. 2, and the second timing signal generator for oscillating and outputting the second signal.
And a second signal generator for generating various timing signals for the image signal processing device based on the second signal and supplying the generated frame pulse to the first signal generator as a reset pulse. 2. The synchronization system for an image signal processing system according to claim 1, wherein: 3. An image pickup apparatus comprising a color separation optical system and a plurality of standard television system image signal solid-state image pickup elements; a first timing signal generator for generating various timing signals for driving the image pickup apparatus; Various high-definition television system timing signals including a reference frequency and a line frequency different from the reference frequency and the line frequency in the output timing signal of the first timing signal generator, and the first timing signal generation A second timing signal generator that selectively generates and outputs one of the various timing signals of the standard television system that is the same as the output timing signal of the device, and the output imaging signal of the imaging device generates the first timing signal Written based on the output timing signal of the instrument,
A buffer circuit read based on the output timing signal of the second timing signal generator; and an image pickup signal read from the buffer circuit and an output timing signal of the second timing signal generator,
An image signal processing system comprising: an image signal of the high definition television system and an image signal processing device for generating and outputting one of the image signals of the standard television system instructed by an external instruction signal; The method for synchronizing an image signal processing system, wherein the first timing signal generator is reset at a frame cycle by a frame pulse output from the timing signal generator. 4. The first timing signal generator includes a first oscillator that outputs a first signal with fixed oscillation, and the first timing signal generator.
And a first signal generator for generating various timing signals for the image pickup apparatus based on the signal No. 1, the second timing signal generator being the second reference frequency of the high definition television system. A second oscillator that oscillates and outputs a signal; a third oscillator that oscillates and outputs a third signal of the standard frequency of the standard television system; and an output signal of the second and third oscillators, Selection means for selecting an output signal from an oscillator of the same television system as the image signal generated by the image signal processing apparatus by the external instruction signal, and various timings for the image signal processing apparatus based on the output signal of the selection means. A second signal generator for generating a signal and supplying the generated frame pulse as a reset pulse to the first signal generator. Image signal processing synchronization scheme of the system described. 5. The frame pulse output from the second timing signal generator resets the first timing signal generator within vertical blanking of the imaging device. 3. The synchronization method of the image signal processing system described in 3.