JPH089321A - Video recording and reproducing device - Google Patents

Abstract

PURPOSE:To allow one set of VTR to execute multiple recording and its reproduction with excellent image quality by providing a rewritable storage circuit to a recording side and providing a rewritable 1st storage circuit and a 2nd storage circuit from which a scanning line data are read twice at a double speed to a reproduction side. CONSTITUTION:A 1st video signal is fed to a switch circuit 2 without any processing in the recording side. On the other hand, a 2nd video signal is once stored in a rewritable storage circuit 1 and read by a control circuit 4. In this case, the 2nd video signal is fed to the circuit 2. The 1st and 2nd video signals are alternately outputted through the circuit 2 based on a switching control signal from the control circuit 4. The multiplexed video signal in the reproduction side is once written in a rewritable 1st storage circuit 6 and one of the two signals is separated and the signal of the same field is outputted twice each. The one of read reproduction signals is written in a 2nd storage circuit section 7, from which the signal of a double speed scanning line is read by a doubled horizontal scanning frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video tape recorder (hereinafter referred to as VTR) for multiplex recording / reproducing of television images.
Said) and the like.

[0002]

2. Description of the Related Art As a conventional recording / reproducing apparatus such as a VTR for performing multiplex recording / reproduction of television (TV) video, Japanese Patent Laid-Open No. 37568/1993 is disclosed. According to the invention,
As a recording method, one field in the frame image of the TV program A and one field in the frame image of the program B are alternately mixed in the recording area (field) of the VTR in order and multiplex-recorded. Is the way. The playback method is
When a desired field, for example, program A is reproduced from the mixed and multiplexed video signals, assuming that program A is recorded in an even field, the video signal read by the tape head is read every field. In this method, only the fields are separated, and the same field is reproduced twice for each of the separated fields to generate a frame image.

However, in the recorded video signal, only one field of the original frame video subjected to the interlace scanning is recorded, and the other fields are not recorded. Therefore, conventionally, the "playback image (field)" shown in FIG.
Since the frame image is artificially generated by reading twice each, there is a problem that the vertical resolution of the reproduced image is reduced to about 1/2.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a recording / reproducing apparatus such as a VTR for performing multiplex recording / reproducing without lowering the vertical resolution.

[0005]

In order to achieve the above object, in a video recording / reproducing apparatus having a recording head for recording a video signal on a recording medium on a recording side, a first video signal and a second video signal are provided. A rewritable storage circuit for storing a video signal; a switch circuit for selectively switching the first video signal and a second video signal read from the storage circuit to output to the recording head; A control signal for reading a second video signal from the storage circuit in synchronization with the first video signal, and a control circuit for generating a switching control signal for switching the switch circuit for each field of the first video signal, On the reproducing side, in a video recording / reproducing apparatus equipped with a reproducing head for reproducing two video signals alternately recorded on the recording medium for each field, the selected reproduction signal is reproduced every field. A rewritable first memory circuit, a second memory circuit that stores the scanning line data read from the first memory circuit and reads twice at double speed, and the second memory circuit that synchronizes with the reproduction signal. A write control signal to the first memory circuit, a read control signal to read a reproduced video signal from the memory circuit twice, and a write control signal to the second memory circuit and a double speed from the second memory circuit. And a control circuit for generating a read control signal for reading the reproduced video signal twice, and is composed of the recording side and the reproducing side.

[0006]

In the recording side, the first video signal is sent from the output circuit as it is to the switch circuit. On the other hand, the second video signal is once stored in the rewritable storage circuit and then read by the control circuit. At this time, the second video signal is read in synchronization with the first video signal and sent to the switch circuit. The switch circuit performs a switching operation for each field of the video signal according to a switching control signal from the control circuit, and alternately outputs the first video signal and the second video signal read from the storage circuit for each field. . This alternate switching operation is
In other words, it is a timing corresponding to the interlaced scanning of the CRT screen, and one screen is formed by two fields, but one field is assigned the first video signal and the other field is assigned the second video signal. Allocate and mix two video signals as one video signal and multiplex. The multiplexed video signal is recorded on the recording medium via the recording head. On the reproduction side, the multiplexed video signal reproduced from the recording medium by the reproduction head selectively rewrites each reproduction signal of the first video signal and the second video signal included in the same video signal at the timing of each field. Write once to the first possible storage circuit, out of the two video signals
Separate one. One of the separated reproduction signals is written in the second storage circuit, read twice at double speed, and is generated as a double speed converted video signal. The video signal converted at the same speed is sent to the display device and displayed on the screen.

[0007]

EXAMPLE A recording / reproducing apparatus according to the present invention will be described below.
This will be described in detail with reference to the drawings. FIG. 1 is a block diagram of an embodiment of a recording / reproducing apparatus according to the present invention. Reference numeral 1 denotes a rewritable storage circuit that stores a first video signal and a second video signal, and is composed of, for example, a 2-port V-RAM. Reference numeral 2 denotes a switch circuit that selectively switches the first video signal and the second video signal read from the storage circuit 1 and outputs the selected video signal to the recording head. A recording head 3 records a video signal on a recording medium. Reference numeral 4 generates a control signal for reading the second video signal from the storage circuit 1 in synchronization with the first video signal and a switching control signal for switching the switch circuit 2 for each field of the first video signal. It is a control circuit for controlling. The above constitutes the recording side of the video recording / reproducing apparatus.

Reference numeral 5 is a reproducing head for reproducing two video signals recorded alternately on the recording medium for each field. 6
Is a rewritable first storage circuit configured to store the read reproduction signal for each field, for example, a rewritable V-RAM. Reference numeral 7 is a second memory circuit configured to store the scanning line data read from the first memory circuit 6 and read the data twice at double speed, which is constituted by, for example, a line memory. Reference numeral 8 denotes a write control signal to the first storage circuit 6 and a read control signal for reading a reproduction video signal from the first storage circuit 6 in synchronization with the reproduction signal, and further to the second storage circuit 7. And a read control signal for reading the reproduced video signal from the second memory circuit 7 twice at a double speed. The above constitutes the reproducing side of the video recording / reproducing apparatus.

The operation on the recording side of the recording / reproducing apparatus according to the present invention will be described with reference to FIGS. On the recording side, the first video signal is sent from the output circuit to the switch circuit 2 as it is. On the other hand, the second video signal is once stored in the rewritable storage circuit 1 and then read by the control circuit 4. At this time, the second video signal is read out in synchronization with the first video signal as shown in FIG.
Sent to The switch circuit 2 performs a switching operation for each field of the video signal according to a switching control signal from the control circuit, and alternately switches the first video signal and the second video signal read from the storage circuit 1 for each field. Output to. This alternate switching operation is, so to speak, a timing corresponding to the interlaced scanning of the CRT screen, and one screen is formed by two fields, but the first video signal is assigned to one of the fields and the other fields are allocated. Assign the second video signal to
It is mixed and multiplexed as one video signal. The multiplexed video signal is recorded on the recording medium via the recording head 3 and then recorded / recorded in FIG.
It is recorded as shown in "Playback image".

The operation on the reproducing side of the recording / reproducing apparatus according to the present invention will be described with reference to FIGS. On the reproduction side, the multiplexed video signal reproduced from the recording medium by the reproduction head 5 selectively reproduces the reproduction signals of the first video signal and the second video signal included in the same video signal at the timing of each field. Once written in the rewritable first memory circuit 6,
One of the two video signals is separated as in "readout video" shown in FIG. 2, and the same field is output twice. Either one of the read and separated reproduction signals is written in the second memory circuit 7, and the horizontal scanning frequency is doubled and read by the double speed scanning line. Further, as shown in FIG. 3, a double-speed reading is performed twice to generate a double-speed converted field video signal, and the field video signal is sent to the display device twice per frame and displayed on the screen. .

[0011]

As described above, the present invention provides a recording / reproducing apparatus such as a VTR for performing multiple recording / reproducing without lowering the vertical resolution. Therefore, multiple recording and reproduction can be performed with good image quality by one VTR. In particular, in a large-sized television, there is an advantage that a scanning line cannot be seen and a smooth image can be realized.

[Brief description of drawings]

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

FIG. 2 is a timing diagram showing an operation on the reproducing side of the recording / reproducing apparatus according to the present invention.

FIG. 3 is a screen image view showing an operation on the reproducing side of the recording / reproducing apparatus according to the present invention.

FIG. 4 is a screen image diagram showing the operation on the reproducing side of the conventional recording / reproducing apparatus.

[Explanation of symbols]

 1 Storage Circuit 2 Switch Circuit 3 Recording Head 4 Control Circuit 5 Playback Head 6 First Storage Circuit 7 Second Storage Circuit 8 Control Circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H04N 5/937 H04N 5/93 C

Claims (3)

[Claims] 1. A video recording / reproducing apparatus having a recording head for recording a video signal on a recording medium on a recording side, comprising a rewritable storage circuit for storing a first video signal and a second video signal. A switch circuit for selectively switching the first video signal and the second video signal read from the storage circuit to output to the recording head; and the storage circuit in synchronization with the first video signal. From the second video signal to the control circuit for generating a switching control signal for switching the switch circuit for each field of the first video signal. In a video recording / reproducing apparatus having a reproducing head for reproducing the two video signals recorded in, a rewritable first memory circuit for storing the selected reproduction signal for each field, A second memory circuit that stores the scanning line data read from the first memory circuit and reads twice at double speed; a write control signal to the first memory circuit in synchronization with the reproduction signal; A read control signal for reading the reproduced video signal from the storage circuit twice, a write control signal for the second storage circuit, and a read control for reading the reproduced video signal twice from the second storage circuit at double speed. A video recording / reproducing apparatus comprising: a control circuit for generating a signal and comprising the recording side and the reproducing side. 2. The video recording / reproducing apparatus according to claim 1, wherein the memory circuit and the first memory circuit are constituted by a 2-port D-RAM. 3. The video recording / reproducing apparatus according to claim 1, wherein the second memory circuit is a line memory.