JPH01140872A - Converting method for different kind of television system video signal - Google Patents

Abstract

PURPOSE:To regenerate the video signal of other system from a video tape on which the video signal of one system was recorded by regenerating the signal as shifting the number of revolutions of a magnetic head and a tape speed differently from those at the time of recording, and writing and reading the output of the magnetic head in and from a picture memory. CONSTITUTION:The video signal, which was regenerated while the number of revolutions of the magnetic head and the tape speed at the time of reproducing are shifted to be different from those at the time of recording by using an NTSC recorded tape reproducing circuit 1 and a speed reducing means 1a, is stored in the memory 31 of a memory device 3 through an NTSC signal processing circuit 2. At the time of the read-out of the memory 31, the signal is converted into a CCIR signal by adding the signal corresponding to the definite number of horizontal periods, and is supplied to a CCIR system monitor receiver 5 through a CCIR signal processing circuit 4.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is an object of the present invention, which reproduces a video tape in which a video signal is recorded at a certain field frequency (vertical synchronization frequency), and reproduces the video signal at another field frequency. The present invention relates to a method of converting a video signal of a different type of television system to output a video signal of a system having

(Prior art) The television standards currently adopted in various countries are roughly divided into NTSC, PAL, and 5E.
There is a CAH system, and a TV set and a magnetic recording/reproducing device (VTR) dedicated to each system are used.

For this reason, for example, if you want to play a videotape produced in an area where NTSC broadcasting is performed in an area where PAL or 5ECAH broadcasting is performed, the VTR and N
A monitor receiver for the TSC system must be prepared,
Extremely inconvenient and rare.

By the way, the difference between the standard television systems is the scanning system,
There are a wide variety of color signal transmission methods, but the most problematic among them is the difference in scanning methods, especially the difference in field frequency (vertical synchronization frequency). Therefore, there is a need for a conversion device that can convert this field frequency and play back video tapes recorded in other formats. but,
To do this, a certain type of playback video signal is written to a memory such as a BBD (bucket print device),
At the time of reading, the clock frequency must be changed and converted to a video signal having a field frequency of another system, but this has the disadvantage of requiring a large capacity memory. Additionally, although there have been devices for converting standard television formats into other formats, these devices are mainly used for broadcasting stations, are extremely expensive, and are not intended for the general public. Therefore, when recording, the video signal of the television system in this region can be recorded, while during playback, the video signal recorded with the television system of another region can be displayed on a monitor receiver dedicated to the television system of this region. There is a need for the development of a video tape recorder with a simple configuration that can play and output tapes.

(Problems to be Solved by the Invention) Conventionally, a simple video signal that can convert a video tape recording a video signal of a standard format of a certain television into a playback video signal of a standard format of another television and output it. There was no way to convert it. Therefore, it is necessary to prepare monitor receivers and VTRs dedicated to each television standard system, which is both inconvenient and uneconomical.

Therefore, the present invention was made in view of the above problems.
It is an object of the present invention to provide a method for converting video signals of different television systems by converting a video tape recording a video signal of a standard system of a certain television into a video signal of a standard system of another television and reproducing the same.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a heterogeneous television that has a predetermined vertical synchronization frequency by slowing down or speeding up the rotational speed of the recording head and the tape speed compared to those during tape recording. Reproducing a magnetic tape on which a system video signal is recorded, processing the reproduced video signal of a different type of television system, and processing a signal corresponding to a total horizontal period per field of the signal of the different type of television system resulting from the signal processing. Alternatively, if signals corresponding to a predetermined number of horizontal periods are stored in the image memory, and signals corresponding to the entire horizontal period are stored, read out the signals, and then read out the signals corresponding to a certain number of non-continuous periods. A different type of television system signal is converted into a predetermined television system signal by extracting a signal corresponding to a number of horizontal periods and adding it to the read signal, and the signal corresponding to the predetermined number of horizontal periods is stored. If the signal is stored and simultaneously read out, the different type of television system signal is converted into a predetermined television system signal, the predetermined television system signal is subjected to signal processing, and the predetermined signal obtained by the signal processing is The television system video signal is sent out to the television monitor for the predetermined television system.

(Function) During playback, the rotational speed of the magnetic head and the tape speed are shifted from those during recording, the horizontal synchronization frequency of the video signal is adjusted to that of the monitor receiver, and the total number of signals corresponding to the horizontal period per field of the video signal or a predetermined number is adjusted. The horizontal synchronization frequency of the video signal is converted by writing the number into the image memory and, when reading it, either as it is or by adding a signal corresponding to a certain number of horizontal periods to create a video signal for one screen.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 2 and 4.

In step 1, as shown in FIGS. 2 and 4, the number of revolutions of the recording head and the tape speed are reduced (for example, 63.5764 times slower) or increased (for example, 64/63.5) than those during tape recording. A magnetic tape on which a video signal of a different type of television system (for example, NTSC system, CCIR system) having a predetermined vertical synchronization frequency is recorded is played back. In step 2, the reproduced heterogeneous television system video signal is converted into signal 51! Let them do X.

In step 3, the total horizontal period (for example, NT
In the SC system, a signal corresponding to 2132H out of 262.5H) or a signal corresponding to a predetermined number of horizontal periods (for example, 312.5H in the CCIR system) (out of 261H) is stored in the image memory. In step 4a, if a signal corresponding to the entire horizontal period (for example, 2f32H> in the NTSC system) is stored, the signal is read out, and then a fixed number of non-consecutive horizontal periods ( For example, by extracting a signal corresponding to 53H in the CCIR system and adding it to the read signal, a signal of a different type of television system (for example, NTSC system) is converted to a signal of a predetermined television system (for example, CCIR system). In step 4b, if a signal corresponding to the predetermined number of horizontal periods (for example, 261H in the CCIR system) is stored, the signal is stored and read out at the same time to be used for a different type of television system (for example, CCIR system).
IR system) signal to a predetermined television system (for example, NT
(SC method) signal. In step 5, the signal of the predetermined television system (for example, CCTR system, NTSC system) is subjected to signal processing. In step 6, the signal-processed video signal of a predetermined television system (CCIR system, NTSC system) is sent to a television monitor for the predetermined television system.

Next, the operation of the first embodiment of the present invention will be explained based on FIGS. 1 and 2. The magnetic recording/reproducing device used as means for carrying out the Tatsumi television video signal conversion method of the present invention includes a rotating drum (not shown) on which two rotating magnetic heads (not shown) are mounted 180 degrees apart. ). Consider a helical scan system in which a magnetic tape is wound diagonally around a magnetic tape. In a magnetic recording/reproducing device that records signals using the SC system, which has a field frequency (vertical synchronization frequency) of 60H2 and 525 horizontal periods included in one frame, the magnetic tape is run at a constant speed. In this state, the rotating magnetic head must be rotated at 30H2, which corresponds to the frame frequency. Therefore, as shown in FIG. 1, during playback using the NTSC signal recorded tape playback circuit 1, the magnetic tape is run at the same speed as during recording, and the rotating magnetic head is rotated at the same speed of 30H2 as during recording. Rotate with . Then, as with the original signal, the reproduced signal has a field frequency of 60H2, the number of horizontal periods (1H) in one field is 262.5, and one horizontal period is an NTSC signal of 63.5 μs.

However, since one horizontal period of the CCIR signal is 64 μs, it is necessary to control the rotation speed of the rotary magnetic head by slightly retarding (63.5/64 times) using the deceleration means 1a so that one horizontal period is 64 μs. At the same time, in order to achieve tracking, it is necessary to control the tape speed by slowing down the rotational speed of the rotary magnetic head by using the deceleration means 1a. By doing this, NTSC
The signal processing circuit 2 outputs an NTSC signal having one field of 262.5 days and one horizontal period of 64 μs, as shown in FIG. 2(A). As shown in FIG. 2 (A), in the memory device 3, the horizontal period (262
62H) is read out from the image memory 31. Next, after reading out signals corresponding to 262 horizontal periods (262H), embedding and reading 53 signals from the reading means 32
Signal corresponding to the horizontal period (53H>) (out of the horizontal periods 262 of the written signal, those that are not consecutive are
The main extracted portion (embedded portion) is read out from the memory 31 and added. Therefore, from the memory device 3, the second
As shown in Figure (8), 315 horizontal periods (315H) are
A video signal to be used as a field is read out, and this is
CH? The signal is output to the signal processing circuit 4. After the second field of the next NrSC signal, writing to the image memory 31 is not performed, and only reading operation from the image memory 31 is performed. Therefore, as shown in FIG. 2(B), each field consists of 315 horizontal periods (315H) until the NTSC signal is written into the image memory 31, and one frame consists of 830 horizontal periods. CCIR video signals are sequentially read out from the memory device 3. In this way, the NTSC video signal is converted into the CCIR video signal. That is, N ding S
Regarding the signal output from the C signal processing circuit 2,
After 12 fields (0,2016 seconds) have elapsed, as shown in FIGS. 2(A) and 2(B), the NTSC signal processing circuit 2
The field start points of the NTSG signal output from the memory device 2 and the CCIR signal output from the memory device 2 coincide. For this reason, the NTSC signal output from the NTSC signal processing circuit 2 is loaded into the image memory 31 at the timing when the field start points of both the signals coincide. This writing is performed once every 12 fields of the NTSC signal. Now, the CCIR video signal reproduced and output from the CCIR signal processing circuit 4 (the number of horizontal periods is 2)
62.5, so it is not a complete CCIR video signal), the CCIR monitor receiver 5 will not display an image. Note that this reproduced image consists of 12 fields (0,201
Since the same image appears during the 6 seconds) period, it visually resembles a robot.

According to this embodiment, a magnetic recording device equipped with one image memory for special playback that can record signals for one field can easily reproduce tapes on which NTSC signals are recorded using this image memory. It is also possible to convert and output a reproduced video signal of the CCIR system.

Next, the operation of the second embodiment of the present invention will be explained based on FIGS. 3 and 4. One horizontal period of the CCIR signal is 64 μs,
Since one horizontal period of the NTSC signal is 63.5 μs,
As shown in FIG. 3, when reproducing a magnetic tape recorded by the CCIR method using the CC:IR signal recorded tape reproducing circuit 11, the rotating magnetic l\rad rotation speed is slightly increased (64/63.5 times). ) The speed increasing means 11a is controlled so that one horizontal period is 63.5 μs. At the same time, the speed increasing means 11a is controlled to increase the tape speed by the same amount as the rotation speed of the rotating magnetic head is increased so that tracking can be achieved. Then, the CCIR signal processing circuit 12 outputs the signal shown in FIG.
), a CCIR signal with one field of 312.5 H and one horizontal period of 63.5 μs is output. The memory device 13 stores signals corresponding to 261 horizontal bright intervals (261H) among the signals corresponding to 312.5 horizontal periods corresponding to one field of the CCIR signal during the P period of FIG. 4 (A>) to the image memory 34. At the same time, as shown in FIG. 4(B), a signal corresponding to 261 horizontal periods is read out from the image memory 34, and this is set as one field, and the NTS
It is output to the C signal processing circuit 14. In the next field, the memory device 13 reads a signal corresponding to 260 horizontal periods (260H) as shown in FIG. 4(B), and outputs this as one field to the NTSC signal@processing circuit 14. In the end, the memory device 13 has a capacity of 261.
1 by alternately reading out signals corresponding to 260 horizontal periods.
A signal including the horizontal period of frame 521 is output to the NTSC signal processing circuit 14. The NTSC signal processing circuit 14 reproduces the NTSC video signal and outputs it to the NTSC monitor receiver 15. However, the writing operation to the image memory 34 of the memory device 13 is performed so that the field start points of the CCIR signal output from the CCIR signal processing circuit 12 and the NTSC signal read from the memory device 13 coincide. 6 of the NTSG signal read out from the memory device 13 as shown in FIG. 4(B).
The frame has a horizontal period of 260.260 (2
60H).

According to this embodiment, CCI can be easily performed using image memory.
Plays back the tape that recorded the R signal and converts it to NTSC.
It is possible to output the playback video signal of the system.

[Effects of the Invention] As described above, according to the method for converting video signals of different television systems of the present invention, a video tape recording a video signal of a standard system of one television can be converted into a video signal of a standard system of another television. It has the advantage that it can be converted and played back.

[Brief explanation of the drawing]

FIG. 1 shows a V
FIG. 2 is a block diagram of a system composed of a TR and a monitor receiver.
FIG. 3 is a block diagram of a system consisting of a VTR and a monitor receiver as means for realizing the second embodiment of the method for converting video signals of different types of television systems according to the present invention. Figure 4 shows the method for converting video signals of different television systems (CCI) of the present invention.
This is an operation timing chart of the second embodiment based on R signal→NTSC signal conversion). 1... NTSC signal recorded tape playback circuit 1a...
Deceleration means 2, 14...NrSC signal processing circuit 3
．． 13... Memory device 4, 12... CCIR signal processing circuit 5... CCIR system monitor receiver 11a... Speed increase means 15... NTSC system monitor receiver 31, 34... Image memory 32 ...Readout, embedding circuit 33...Adder agent Patent attorney Nori Chika Ken Shu Kanshu Hiroshi Uji

Claims (1)

[Claims] A magnetic tape on which a different type of television system video signal having a predetermined vertical synchronization frequency is recorded is reproduced by slowing down or increasing the rotational speed of the recording head and the tape speed compared to those during tape recording, and the reproduced foreign type television is reproduced. A system video signal is subjected to signal processing, and a signal corresponding to an entire horizontal period or a predetermined number of horizontal periods per field of a different type of television system signal resulting from the signal processing is stored in an image memory. If a signal corresponding to a horizontal period is stored, the signal is read out, and then signals corresponding to a certain number of non-consecutive horizontal periods are extracted from the signal and added to the read signal. By converting a different type of television system signal into a predetermined television system signal, if a signal corresponding to the predetermined number of horizontal periods is stored, the signal is stored and simultaneously read out to convert the different type of television system signal into a signal of a predetermined television system. converting the signal into a predetermined television system signal, subjecting the predetermined television system signal to signal processing, and directing the signal-processed predetermined television system video signal to a television monitor for the predetermined television system. A method for converting video signals from different television systems, characterized by transmitting video signals from different television systems.