JPH0797866B2 - Color video player - Google Patents

Description

TECHNICAL FIELD The present invention relates to a color video reproducing apparatus having excellent color reproducibility.

[Prior Art] A conventional general VTR (video tape recorder) is configured to record a composite color video signal (color TV signal) according to the NTSC system supplied from a camera. NT
In the SC method, R (red), G (green), and B (blue) are not transmitted as they are, and R + G + B is sent as a luminance signal Y and two color difference signals (RY) and (BY) are sent. To send I and Q signals. With this configuration, it is possible to transmit the color signal and the luminance signal in the limited frequency band.

However, since the frequency bands of the R, G, and B signals are limited, high fidelity recording / reproduction was impossible. In order to solve this type of problem, Japanese Patent Application Laid-Open No. 62-14587 and Japanese Patent Application No. 62-153107 have proposed a system for independently recording and reproducing R, G and B signals.

[Problems to be Solved by the Invention] In the above proposed method, R from a VTR or a video disc,
A time division multiplexed signal of G and B signals is output, and the time division multiplexed signal is separated into independent R, G and B signals based on the identification signal. By the way, if the missed detection of the identification signal occurs,
Precise separation of R, G, B signals has become impossible.

Therefore, it is an object of the present invention to provide a color video reproducing device capable of continuing reproduction even when a situation in which the identification signal cannot be detected occurs.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a time division multiplexing arrangement in which a red (R) signal, a green (G) signal, and a blue (B) signal are divided by fields or frames. In addition, the red (R), green (G), and blue (B) identification signals for identifying the red (R) signal, the green (G) signal, and the blue (B) signal are output from the vertical synchronization signal section. A video signal generator for generating a time division multiplex color video signal added in a predetermined order until the next video signal section, and a time division multiplex color video signal generated by the video signal generator for red (R ) Signal, green (G) signal, and blue (B) signal are separated, and red (R) signal and green (G) of the same or near field or frame are separated.
Memory for red (R), green (G) and blue (B) signals for simultaneously outputting a signal and a blue (B) signal, and a vertical synchronization signal for detecting a vertical synchronization signal from the time division multiplexed color video signal A detection circuit, an identification signal detection circuit that detects the red (R), green (G), and blue (B) identification signals in a predetermined order from the time division multiplexed color video signal, and the vertical synchronization signal detection circuit. The time-division multiplexed color video signal is red (R), green (based on the vertical synchronization signal and the red (R), green (G) and blue (B) identification signals detected by the identification signal detection circuit. G) and for controlling the memory for the red (R), green (G) and blue (B) signals so as to be separated into the blue (B) signals, which are obtained from the identification signal detection circuit. It may be detected next to the red (R), green (G) or blue (B) identification signal. An expected identification signal is formed by determining an expected identification signal based on the arrangement of the red (R), green (G), and blue (B) identification signals in a predetermined order, and the identification signal detection circuit performs the identification. When the signal is not detected, the identification signal which is not detected is estimated based on the periodicity of the arrangement of the identification signals detected in the past to form the expected identification signal, and whether the vertical synchronization signal is detected or not is determined. If a determination result indicating that the vertical synchronization signal is not detected is obtained, a pseudo vertical synchronization signal is generated,
When the determination result indicating that the vertical synchronization signal is detected and the pseudo vertical synchronization signal are obtained, the red (R),
In the memory for green (G) and blue (B) signals, the time division multiplexing is performed in the memory of the color that matches the identification content of red (R), green (G) and blue (B) of the expected identification signal. A memory control circuit for generating a control signal for extracting and writing the red (R), green (G) or blue (B) signal from a color signal, and the red (R), green (G) and blue (B) The present invention relates to a color video reproducing apparatus provided with color monitor means for reading red (R), green (G) and blue (B) signals from a signal memory to obtain a reproduced image.

[Operation and Effect of the Invention] Since the red (R), green (G), and blue (B) identification signals are recorded in a predetermined order, the next identification signal can be expected. Further, even if the situation in which the identification signal cannot be detected occurs, the identification signal that cannot be detected can be predicted based on the identification signals detected in the past. In the present invention, the write control of the memory for red (R), green (G) and blue (B) signals is executed according to the identification content of red (R), green (G) and blue (B) of the expected identification signal. Therefore, even if the identification signal becomes undetectable, the desired red (R) for the memory,
The green (G) and blue (B) signals can be written separately, and good reproduction can be continued.

[Embodiment] Next, a color video signal recording / reproducing apparatus according to an embodiment of the present invention will be described with reference to FIGS.

The color camera 1 of FIG. 1 has a three-color separation filter 2, an R image pickup tube 3, a G image pickup tube 4, and a B image pickup tube 5, and
G and B signals are generated. The R, G, B identification signal adding circuits 6, 7, 8 are connected to the R, G, B image pickup tubes 3, 4, 5. Each of the identification signal adding circuits 6, 7 and 8 is connected to the synchronizing signal generator 9 and is set to a predetermined position determined based on the synchronizing signal, that is, R during the vertical blanking period Tb shown in FIGS. 2 and 3. G and B identification signals S _R , S _G and S _B are added. This R,
The G, B identification signals S _R , S _G , S _B are added after the vertical synchronization signal (V-SYNC) in the vertical blanking period Tb. The identification signals S _R , S _G , and S _B are distinguished from each other by different times T from the beginning of one horizontal scanning period (1H) as shown in FIG.
This is achieved by adding identification pulses to 1, T2 and T3.

The time division multiplexing switch 10 includes contacts a, b, c connected to the R, G, B identification signal adding circuits 6, 7, 8 and is controlled by a switch control circuit 11 to output a time division multiplexing signal. . The switch control circuit 11 switches the contacts a, b, and c of the switch 10 on a frame-by-frame basis on the basis of the synchronization signal supplied from the synchronization signal generator 9.

The time division multiplexed signal obtained on the common output line 12 of the switch 10 is the R signal to which the R identification signal S _R is added and the G signal and the B identification signal S to which the G identification signal S _G is added as shown in FIG. _B added B signal. Therefore, the R, G, and B signals are transmitted only for one frame in three frame periods, and the remaining two frames are discarded. However, each R, G, B signal has a wider frequency band than the conventional one.

The VTR 13 connected to the time division multiplex switch 10 is for performing FM recording and reproduction of the time division multiplex signal using a common recording medium (magnetic tape), and is substantially the same as a general-purpose VHS type, beta type, etc. belongs to. If the frequency band of 6 MHz is frequency-divided with R, G, and B signals, the single color allocation is 2 MHz. On the other hand, in the present invention, 6 MHz can be used for a single color signal. Therefore, the VTR 13 having the same frequency band as the conventional one can record the color signal with a frequency band width three times that of the conventional one.

On the output line of the VTR 13 capable of obtaining a time division multiplex signal which is substantially the same as the recorded time division multiplex signal, an R frame memory 15, a G frame memory 16, a B frame memory 17 and a memory control circuit are provided. 18 connected.

The memory control circuit 18 reads the R, G, B identification signals S _R , S _G , S _B contained in the time division multiplexed signal shown in FIG.
Based on this, the control signals for the frame memories 15, 16 and 17 are formed.

The R, G, and B frame memories 15, 16 and 17 are controlled by the memory control circuit 18 to convert the time division multiplexed signal into the R signal, the G signal and the B signal.
Read separately from the signal. That is, R frame memory
Only the R signal is written in 15 and the G frame memory 16
In the frame memory 17 for B, only the B signal is written.

The R, G, B frame memories 15, 16, 17 are connected to a monitor 19 with R, G, B input terminals. The R, G, B frame memories 15, 16, 17 continuously output R, G, B signals. That is, the same color signal is read three times repeatedly until the next new color signal is written. As a result, the R, G, B signals can be simultaneously applied to the monitor 19.

It is not possible to always give the monitor 19 the color signals simultaneously imaged by the R, G, and B image pickup tubes 3, 4, and 5 at the same time. However, when the movement of the subject is slow, the movement of the subject in the 3-frame period can be ignored. R, G, B
Since the frequency band of the signal is about 3 times that of the conventional one,
In the case of a slow-moving subject, color can be reproduced with high fidelity.

FIG. 5 shows the memory control circuit 18 in detail, and FIG. 6 shows the flow of signal processing in the memory control circuit 18. The memory control circuit 18 includes a vertical synchronization signal detection circuit 18a, an identification signal detection circuit 18b, and a memory control signal formation circuit 18c. The vertical sync signal detection circuit 18a detects the vertical sync signal (V-SYNC) shown in FIG. 3 of the video signal. Identification signal detection circuit 18
b detects a R, G, B identification signal shown in FIG. 4 by a timer.

The memory control signal forming circuit 18c includes a microprocessor and executes signal processing shown in FIG. 6 and control of reading signals from the memories 15, 16 and 17. First, in block a, it is determined whether or not the vertical synchronizing signal detection circuit 18a has detected the vertical synchronizing signal (V-SYNC). If YE
If S, switching of the memory control signal is executed in the next block b. This switching is performed based on the expected identification signal and before the identification signal is detected. Next, in block c, an identification signal is input, and in block d, the next identification signal is predicted to form a predicted identification signal. This predicted identification signal is used to switch the signal of block b. A time-over determination block e is provided to determine whether or not the vertical synchronization signal has been accurately detected. In this block e, it is determined whether or not the period in which the vertical synchronizing signal is not detected continues for a certain time or more.
If the vertical sync signal is missed, it is determined that the time is over and a pseudo vertical sync signal is generated.
The signal switching is executed at the block b.

If the detection failure of the identification signal occurs, the expected identification signal is formed based on the past identification signals. Since the identification signal has R, G, and B periodicity, a plurality of identification signals can be easily obtained. Therefore, according to the present embodiment, even if the vertical or horizontal sync signal or the identification signal is lost or even if the pseudo identification signal or the pseudo synchronization signal is generated, the R, G, B signals are not affected by this. The separation can be performed accurately.

Also, without waiting for the detection of the identification signal, the switching of the writing of the memories 15, 16 and 17 is executed immediately when the vertical synchronizing signal is detected, so that a dropout may occur at the beginning of the vertical scanning period based on the switching. Is less.

[Another Embodiment] Next, a color video signal recording / reproducing apparatus according to another embodiment of the present invention will be described with reference to FIGS. However,
The components denoted by the reference numerals 1 to 19 in FIG. 7 are substantially the same as those designated by the same reference symbols in FIG. 1, and therefore their explanations are omitted. In the embodiment of FIG. 7, G identification signal adding circuits 7 and B are provided.
Frame memories 20 and 21 are connected between the identification signal adding circuit 8 and the switch 10. The frame memories 20 and 21 are
It is the same as the frame memory 15, 16, 17 of the reproduction system, and includes an A / D converter and a D / A converter, and A / D converts the G signal and the B signal to which the identification signal is added. The data is written in the memory, and then read and D / A converted. The frame memories 20 and 21 are provided as delay circuits, and delay the G and B signals as shown in FIGS. 8 (D) and 8 (E).

FIG. 8 shows the arrangement of the R, G, B signals without the identification signals S _R , S _G , S _B. Each image pickup tube 3, 4, 5 as a color signal generator
If the R, G and B signals are sequentially output as shown in FIGS. 8A, 8B and 8C, the R signal is sent to the switch 10 as it is. However, the G signal and the B signal are delayed by the frame memories 20 and 21 and sent. The G signal frame memory 20 provides the G signal with a delay of one frame. As a result, the G1 signal in the period t0 to t1 in FIG. 8B is output in the period t1 to t2 as shown in FIG. 8D. The B signal frame memory 21 provides the B signal with a delay of two frames. As a result, the B1 signal in the period t0 to t1 in FIG. 8 (C) is output in the period t2 to t3 as shown in FIG. 8 (E). Since the switch 10 sequentially extracts the signals of FIGS. 8A, 8D, and 8E, it outputs the time division multiplexed signal shown in FIG. 8F.

The time division multiplex signal of FIG. 8 (F) is recorded by the VTR 13. When this recorded signal is reproduced, the same signal
It is obtained as shown in FIG. The R, G, B frame memories 15, 16 and 17 have a built-in A / D converter for input and a D / A converter for output (not shown), and a frame memory for writing and a frame memory for reading. It has a built-in frame memory. The R, G, and B signals of FIG. 9 (A) are extracted to the writing frame memories of the memories 15, 16 and 17 to form the ninth frame.
It is written as shown in FIGS. The data in the write frame memory is transferred to the read frame memory, and t1 as shown in FIGS. 9 (E), (F) and (G).
The R1, G1, and B1 signals of the same imaging period are output within the same period of up to t2. That is, the same R, G, B signals are continuously output for three frames. Since each color signal of the same imaging period is output in the same period, no color shift occurs. The memory control circuit 18 includes not only the same circuit as that shown in FIG. 5, but also a circuit for forming a signal for controlling the read frame memory.

[Modification] The present invention is not limited to the above-described embodiments, and the following modifications are possible, for example.

(1) The identification signal may be added after the switch 10. In this case, the identification signal may be added after a predetermined time from the time of switching the switch or during the horizontal scanning period.

(2) The video signal may be switched by the switch 10 in units of fields or in units of several frames.

(3) The identification signal may be a binary digital signal or a frequency signal.

(4) Instead of the VTR 13, an apparatus for recording / reproducing a video signal on an optical disk, a magnetic disk or the like may be used.

(5) Instead of the three-tube color camera 1, a single-tube camera using a stripe filter may be used. CCD
You may use the imaging device which used.

(6) In FIG. 7, a frame memory may be connected to the output line of the R identification signal adding circuit 6 to give a predetermined delay to all of the R, G and B signals.

(7) Instead of the frame memories 20 and 21, another delay circuit may be used.

(8) Instead of discarding the R, G, B signals by the switch 10, all the R, G, B signals may be time-compressed and recorded in the VTR 13.

[Brief description of drawings]

1 is a block diagram showing a video signal recording / reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a waveform diagram showing an input signal of the VTR of FIG. 1, and FIG. 3 is a vertical blanking period of a video signal. FIG. 4 is a detailed view of a part of FIG. 4, FIG. 4 is a view showing the arrangement of R, G, and B identification signals, FIG. 5 is a block diagram showing the memory control circuit of FIG. 1, and FIG. FIG. 7 is a flow chart showing signal processing of the control circuit, FIG. 7 is a block diagram showing a video signal recording / reproducing apparatus according to another embodiment of the present invention, and FIG. 8 is a view showing the states of points A to F of FIG. 7 in principle. FIG. 9 is a signal arrangement diagram shown in FIG. 9, and FIG. 9 is a signal arrangement diagram showing states of respective parts of the reproducing system in FIG. 1 ... Color camera, 2 ... Three-color separation filter, 3 ...
R image pickup tube, 4 ... G image pickup tube, 5 ... B image pickup tube, 6
... R identification signal addition circuit, 7 ... G identification signal addition circuit,
8 …… B identification signal addition circuit, 10 …… Time division multiplexing switch, 13 …… VTR, 15,16,17 …… Frame memory, 18 ……
Memory control circuit.

Claims (1)

[Claims] 1. A red (R) signal, a green (G) signal, and a blue (B) signal are divided by fields or frames and time-division multiplexed, and at the same time, a red (R) signal and a green (G) signal are arranged. Red (R), green (G) and blue (B) identification signals for distinguishing the signal from the blue (B) signal are added in a predetermined order from the vertical synchronizing signal section to the next video signal section. A video signal generator for generating a time division multiplexed color video signal, and a time division multiplexed color video signal generated from the video signal generator for a red (R) signal, a green (G) signal and a blue (B) signal. To output a red (R) signal, a green (G) signal, and a blue (B) signal of the same or near field or frame at the same time, and separate them into red (R), green (G), and blue (B). Vertical sync signal is detected from the signal memory and the time division multiplexed color video signal A vertical synchronizing signal detecting circuit for detecting the red (R), green (G) and blue (B) identifying signals in a predetermined order from the time division multiplexed color video signal; Vertical sync signal detected by the detection circuit and red (R), green (G) detected by the identification signal detection circuit
And a red (R), a green (G), and a red (R), a green (G), and a blue (B) signal to separate the time-division-multiplexed color video signal based on a blue (B) identification signal. A memory for controlling a blue (B) signal, which is red (R), green (G) or blue (B) obtained from the identification signal detection circuit.
An expected identification signal is formed by determining an identification signal expected to be detected next to the identification signal based on the arrangement of the red (R), green (G) and blue (B) identification signals in a predetermined order. Then
When the identification signal is not detected by the identification signal detection circuit, the expected identification signal is formed by inferring the identification signal that has not been detected based on the periodicity of the arrangement of the identification signals detected in the past, It is determined whether or not a vertical sync signal is detected, and when a determination result indicating that the vertical sync signal is not detected is obtained, a pseudo vertical sync signal is generated to confirm that the vertical sync signal is detected. When the determination result shown and the pseudo vertical synchronization signal are obtained, red (R), green (G) of the predicted identification signal in the memory for red (R), green (G) and blue (B) signals. And a control signal for extracting and writing the red (R), green (G), or blue (B) signal from the time-division multiplexed color signal into a memory of a color that matches the identification content of blue (B). The memory control circuit that is generated, and the red (R), (G) and blue (B) red from the signal memory (R), green (G) and blue (B) color video reproducing apparatus and a color monitor means for obtaining a read reproduced image signal.