JPH06125526A - Video signal recorder - Google Patents

Abstract

PURPOSE:To photograph a high speed moving object without requiring a special device and to project plural lapse of time screens on the same monitor screen by performing a photographing and the writing to a memory by a high speed timing signal and performing the reading encode from the memory by a standard timing signal. CONSTITUTION:A ST signal every 1/60 seconds generated by a standard system timing(ST) signal generation part 5 is converted into an HT signal every 1/240 seconds which is four times by a (n) times high speed timing (HT) signal generation part 6. This HT signal is imparted to a video camera 1 and an A/D conversion circuit 2, a changeover switch 9 is made on a W or R side and the HT signal or the ST signal is imparted to a memory 3 via writing or reading address generator 1 or 8. Namely, the writing to a photographing and the memory 3 is performed by imparting the HT signal, and the reading from the memory 3 and the encode by an encoder 10 is performed by imparting the ST signal. Thus, a high speed moving object is photographed without requiring a special device and 4 sheets of the lapse of time screen can be obtained on the same monitor screen at the same time.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is used to record and analyze fast moving images using a video camera. The present invention particularly relates to an inexpensive device for recording a fast-moving image by using a standard (NTSC, PAL, etc.) video tape recording device.

[0002]

2. Description of the Related Art As a standard system for television broadcasting, the NTSC system is adopted in Japan and the PAL system is adopted in Europe, and a large number of video cameras and video signal recording devices based on these standard systems are widely used. 1 in NTSC system
60 fields are transmitted per second, and in the PAL system, 50 fields are transmitted per second. This standard was established as this speed is sufficient for the sense of the human eye.

On the other hand, video camera devices are often used to capture and analyze the movement of objects. It is in widespread demand for scientific research, industrial automation, sports training and much more. Generally, the movement of an object is photographed by a standard video camera, recorded on a video tape, and the video tape is reproduced in slow motion for observation and analysis.

If the movement of the subject is particularly high, when a fast moving image is captured and analyzed using the video camera of this standard system, the position of the subject is changed from one field to the next. Is a big movement, which is not enough. The first method conventionally used for this purpose uses a video camera and a video tape, supplies the video camera with a signal faster than the standard method (for example, 200 fields / second), and records it on the video tape. To do. Further, the second method conventionally used is to supply a video camera with a signal faster than the standard method, convert the output signal into a digital signal, and record the digital signal in an integrated circuit memory.

[0005]

According to the first method of the prior art described above, the video tape must also be operated at high speed in accordance with the video camera. In other words, it is necessary to increase the rotation speed of the video head of the video tape, and the video tape with a special structure is used.
Inevitably, the device becomes large and expensive.

The second method of the prior art described above requires an enormous capacity for the integrated circuit memory, which is not a practical device. Therefore, in the conventional device of the above-mentioned second method, the area of the integrated circuit memory is used by circulating it endlessly, and only the last part of the image taken remains in the integrated circuit memory. However, there is a drawback that the recorded contents cannot be viewed after being reproduced while a person is not monitoring and operating.

The present invention solves these drawbacks.
It is an object of the present invention to provide a high-speed video signal recording device which can effectively use a small memory capacity without requiring a special video tape recording device.

[0008]

The present invention comprises a video camera, an AD conversion circuit for converting the output signal of the video camera into a digital signal, and a memory for recording the output digital signal of the AD conversion circuit. In a video signal recording device, a timing signal (where n is an integer of 2 or more) that is n times faster than the standard method is supplied to the video camera and the AD conversion circuit, and the standard method is used when writing to the memory as an address signal. A timing signal generating circuit for supplying a timing signal n times faster than the standard timing signal and supplying the standard timing signal at the time of reading.

This is common to the second method of the above-mentioned prior art and the video camera and its timing signal, but the number of pixels is set so that an image of n fields is recorded in the memory area which becomes one field in the standard system. Control timing etc.

When the contents recorded in the memory are read by the timing signal of the standard system, it is possible to take out the screen in which n images are arranged in one field of the standard system. When the value of n is set to any one of m ² (m is an integer of 2 or more) such as 4, 9, 16 or the like, an image whose aspect ratio of the image to be extracted does not change can be extracted. Further, it is possible to adopt a configuration in which each of the two memories is provided and writing or reading of the memories is alternately switched.

[0011]

Since the video camera is supplied with timing that is n times faster than the standard timing signal, an image signal that is n times faster is sent to the output of the video camera.
This is converted into a digital signal by an AD conversion circuit and recorded in a memory by a standard timing signal. Then, an image of n fields is recorded in one field of the standard method. However, although the resolution of the image is 1 / n, it is possible to reliably capture the movement of the subject from one field to the next field.

In the device of the present invention, the memory capacity is 1 / n as compared with the second method of the prior art. Further, since a standard type device can be used as the video tape and the other circuit devices can be realized easily and inexpensively by digital circuits, the device can be constructed at extremely low cost. Compared with the above-mentioned first method of the prior art, the device of the present invention is extremely superior in that no special video tape recording device is required.

It is also possible to provide two of the above memories so that while one is being read by the change-over switch, the other is writing, so that recording can be performed continuously. Even with this configuration, the memory capacity is 2 / n.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of a first embodiment device of the present invention. The first embodiment of the present invention will be described as an NTSC system.

The present invention is a memory comprising a video camera 1, an AD conversion circuit 2 for converting the output signal of the video camera 1 into a digital signal, and an integrated circuit for recording the output digital signal of the AD conversion circuit 2. In the video signal recording apparatus having the above-mentioned 3, a timing signal (n is an integer of 2 or more) which is n times faster than the standard method is supplied to the video camera 1 and the AD conversion circuit 2, and the memory 3 is written as an address signal. A timing signal generating circuit 4 for supplying a timing signal n times faster than the standard method at the time of writing and supplying the timing signal of the standard method at the time of reading is provided. Further, the memory 3 is provided with a change-over switch 9 as a change-over means for giving a timing signal of the standard method or n times faster than the standard method. Further, an encoder 10 which is a DA conversion circuit for reading the contents of the memory 3 and converting it into a video signal of the standard system is provided, and the timing signal generating circuit 4 uses the standard as a read timing signal of the memory 3 and a timing signal of the encoder 10. This is a configuration including means for supplying a timing signal of the system. The n is any one of m ² , such as 4, 9 and 16 (m is an integer of 2 or more).

Next, the operation of the apparatus according to the first embodiment of the present invention will be described with reference to FIG.
~ It demonstrates with reference to FIG. FIG. 2 is a diagram showing the relationship between the standard timing signal, the n-fold faster timing signal and the field. FIG. 3 is a diagram showing a state in which an image for four fields of an n times faster timing signal is stored in a memory area for one field of a standard timing signal. FIG. 4 is a diagram showing a state in which a screen for four fields is displayed on the screen of the monitor television. The timing signal generating circuit 4 is composed of a standard system timing signal generating section 5 and an n-times high speed timing signal generating section 6. The standard system timing signal generator 5 generates a timing signal for every 1/60 seconds required for an operation of 1 field 1/60 seconds in the NTSC system. Further, the n-fold high-speed timing signal generator 6 multiplies the timing signal generated by the standard timing signal generator 5 every 1/60 second by n times, thereby
A timing signal is generated every 1/60 ns required for 60 ns operation. The value of n is m ^2, such as 4, 9 and 16 (where m is 2) depending on the operation speed of the subject to be photographed.
Either of the above integers) is preset. Here, a case where n = 4 will be described. Therefore, the timing signal generated from the n-times high speed timing signal generator 6 is generated every 1/240 seconds. The timing signal generated every 1/240 seconds is applied to the video camera 1 and the AD conversion circuit 2 as shown in FIG. 1, and when the changeover switch 9 is on the "W" side, the write address generator 7 To the memory 3 via. The standard timing signal is given to the memory 3 via the read address generator 8 when the changeover switch 9 is on the "R" side, and at the same time given to the encoder 10 which is a DA conversion circuit.

A video signal which is an analog signal photographed by the video camera 1 in one field 1/240 second is A
It is input to the D conversion circuit 2. The AD conversion circuit 2 converts the input analog video signal into a digital signal with a timing signal every 1/240 second. The video signal converted into a digital signal by the timing signal every 1/240 seconds is written into the memory 3 every 1/240 seconds. This state is shown in FIG. NT of memory 3
Four video signals of 1/240 second per field are stored in an area for storing one video signal of 1/60 second per field of SC system. This state is shown in FIG. The apparatus of the embodiment of the present invention has a configuration in which four images are stored in the order of shooting in the order of upper left, upper right, lower left, and lower right.

The image stored in the memory 3 in this way is
When the changeover switch 9 or 12 is switched to the "R" side, the standard timing signal is read. When reading out, the image is read out in 1 field / 60 seconds of the NTSC system, so that the image of one group of 4 sheets shown in FIG. 3 becomes 1 field and is read out. The read video signal is DA
It is converted into an analog signal by the encoder 10 which is a conversion circuit, and is sent to the monitor television 15 and the VTR 16.
FIG. 4 shows an image on the monitor television. On the same screen, top left,
Images can be viewed simultaneously in the order of upper right, lower left, and lower right, following the passage of time every 1/240 seconds. It has been already described that the value of n is preset to any one of m ² (m is an integer of 2 or more) such as 4, 9, 16 according to the operation speed of the subject to be photographed. The reason is that the aspect ratios of a plurality of screens that are simultaneously captured are not changed when the images are output to the monitor television 15 as shown in FIG.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram of a second embodiment device of the present invention. The second embodiment of the present invention is characterized in that, in addition to the memory 3 of the device of the first embodiment of the present invention, another memory 13 and changeover switches 12 and 14 are further provided. The changeover switches 9, 12, 14 are arranged so that data is read from one of the memories 3 and 13 while the other is being written.
Operate each. With such a configuration, continuous shooting can be realized.

The standard system is not limited to the NTSC system, and similarly, the present invention can be implemented in any standard system.

[0021]

As described above, according to the present invention, a standard video camera can be used for photographing a moving object at a high speed, and a special video tape recording device is not required. Moreover, a small memory capacity can be effectively used. Further, when the image is output to the monitor television, four images can be simultaneously viewed on one screen over time.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a second embodiment device of the present invention.

FIG. 3 is a diagram showing a relationship between a standard timing signal, an n-fold faster timing signal, and a field.

FIG. 4 is a diagram showing a state in which an image for four fields of an n-times high speed timing signal is stored in a memory area for one field of a standard timing signal.

FIG. 5 is a diagram showing a state in which a screen for four fields is displayed on the screen of a monitor television.

[Explanation of symbols]

 1 Video Camera 2 AD Conversion Circuit 3, 13 Memory 4 Timing Signal Generation Circuit 5 Standard Method Timing Signal Generation Unit 6 n-times High Speed Timing Signal Generation Unit 7 Write Address Generator 8 Read Address Generator 9, 12, 14 Changeover Switch 10 Encoder 11 Output terminal 15 Monitor TV 16 VTR

Claims (4)

[Claims] 1. A video signal recording apparatus comprising: a video camera, an AD conversion circuit for converting an output signal of the video camera into a digital signal, and a memory for recording the output digital signal of the AD conversion circuit. Timing signals n times faster than the standard method for the camera and the AD conversion circuit (where n is an integer of 2 or more)
The memory is provided with a timing signal generation circuit for supplying, as an address signal, a timing signal which is n times faster than the standard method at the time of writing as an address signal and a timing signal of the standard method at the time of reading. Video signal recorder. 2. An encoder for reading the contents of the memory and converting it into a video signal of the standard system, wherein the timing signal generating circuit has a timing signal of the standard system as a read timing signal of the memory and a timing signal of the encoder. Claim 1 comprising means for supplying
The video signal recording device described. 3. The video signal recording apparatus according to claim 1, wherein the n is m ² (m is an integer of 2 or more). 4. The video signal recording apparatus according to claim 1, further comprising: two memories each, and a means for alternately switching between writing and reading of the memories.