JPH0773360B2 - Still image playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still image reproducing apparatus, and particularly to a reproducing apparatus suitable for obtaining a good still image.

[Background of the Invention]

A still image signal of one frame is recorded on a recording medium such as an audio track of a video tape or an audio tape, and at the time of reproduction, the reproduced still image signal is temporarily written in a memory.
A technique is known in which this is repeatedly read to reproduce a still image. In this technology, for example,
As disclosed in Japanese Patent Laid-Open No. 56-40370 and Japanese Patent Laid-Open No. 56-61873, when recording on a recording medium, a still image signal is digitized and time-axis expanded to obtain a narrow band signal,
Recording on a recording medium running at low speed is possible. Also,
When reproducing from the recording medium, the still image reproducing apparatus having the above memory performs time axis compression and analogization of the reproduced still image signal to form a video signal in which frames of the same content are repeated.

Here, in the conventional still image reproducing device disclosed in the above-mentioned patent publication, one field of the memory is used as the memory.
Two RAMs (random access memories) are used, and still image signals are written one field at a time,
Once written to them, they are then read out alternately at a rate well above the writing rate. As a result, one frame of still picture signal returned to the original time axis is repeatedly obtained, and still picture reproduction is performed.

By the way, in the case where a plurality of still image signals are recorded on a recording medium, and these are sequentially reproduced to perform still image reproduction, in the above-described conventional technique, when still images are reproduced for a certain still image signal, When the next still picture signal is reproduced from the medium, the reproduced still picture signal must be written in each RAM in order to perform the still picture reproduction for this, and the still picture reproduction is stopped for this writing time. Will end up. This stop period is substantially equal to the period of the still image signal reproduced from the recording medium and is a considerably long period. Also,
When a plurality of still image signals are continuously recorded on the recording medium without a gap, the reproduction of the next still image signal is started immediately after the reproduction of one still image signal is ended. This means that still image playback is impossible.

To solve this problem, add the same RAM to
When the next still image signal is reproduced from the recording medium while reading is performed by one of the pair of RAMs, the still image signal is written to the other pair of RAMs.
RAM for reading when this writing is completed
It is possible to switch pairs.

However, according to such a still image reproducing device, there is a problem that the number of large-capacity and expensive RAMs increases, and the still image reproducing device becomes large-scale and expensive.

[Object of the Invention]

It is an object of the present invention to solve the above-mentioned problems of the prior art, reduce the memory capacity, and perform still image reproduction for a plurality of still image signals continuously. To provide.

[Outline of Invention]

To achieve this object, the present invention uses a memory with a capacity of 3 fields, allocates a memory for 2 fields for still image reproduction, and allocates a memory for the remaining 1 field for rewriting a still image signal. The feature is that the memory for one field is sequentially switched for reproducing a still image so that the switching can be smoothly performed during a period when the next still image signal is sent.

Example of Invention

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a still picture reproducing apparatus according to the present invention, in which 1 is a reproducer for reproducing a still picture signal recorded on a tape, and 2 is signal processing for processing the reproduced signal. Circuits, 3, 4 and 5 are RAMs that store still image signals for one field, 6 is an MPX (multiplexer) that selects the still image signals read from RAM 3, 4 and 5, 7 is a digital signal to a video signal D / A converter for converting to, 8 is RAM
This is an address control circuit that controls the addresses of 3, 4, and 5.

FIG. 2 is a time chart waveform for explaining the operation of FIG.

The operation of this embodiment will be described below with reference to FIGS. 1 and 2.

The still image signal read from the regenerator 1 is demodulated by the signal processing circuit 2 and then sent to the RAM in the order of an odd field (odd) and an even field (even) in units of one field. Under the control of the address control circuit 8, the still image signal is written in the RAM in the order of the RAMs 3, 4 and 5 field by field. RAM3 is the period of A to B in FIG. 2, RAM4 is C
In the period from D to D, the RAM 5 is written with a still image signal for one field in the period from E to F.

At the time of reading, the RAM data is read in an extremely short cycle (that is, a standard one field period) with respect to the writing time. This time corresponds to 1/60 second in the NTSC system, for example. In the still image signal read from the RAM, the RAM3 is selected by the MPX6 from the point B where the RAM3 finishes writing the odd field data of the still image 1, and the field image of the still image 1 is repeatedly output. Then RA
From the point D to the point F at which the even field data of the still image 1 is written to M4, the MPX6 alternately selects the RAMs 3 and 4 and outputs the frame image composed of both even and odd fields. At this time, the odd field of the still image 2 next to the section from the point E to the point F is written in the RAM 5. R at point F
When the writing of the odd field data of the next still image 2 in AM5 is finished, MPX6 selects only RAM5, and this RA
The still image data from M5 is repeatedly output. The even field data of the next still image 2 is written in RAM3,
When this writing is completed, the RAMs 5 and 3 are read out alternately.

In this way, one of the three RAMs is used for writing the field data of the next still image, and the two RAMs are alternately read until the writing to this RAM is completed. As a result, even if different still image signals are successively reproduced from the recording medium, different still images can be reproduced without interruption.

FIG. 3 is a block diagram showing another embodiment of the still picture reproducing apparatus according to the present invention. 10 to 12 are MPXs, 13 is a signal processing circuit, and the same reference numerals are given to the portions corresponding to FIG. I am wearing it.

FIG. 4 is a block diagram showing a specific example of the signal processing circuit 13 in FIG. 3, in which 20 is a line delay circuit and 21 is an adder.

FIG. 5 is a timing chart showing the operation of this embodiment.

In the embodiment shown in FIG. 1, the point B to D in FIG.
A field image is displayed during the period of points, and a frame image is displayed during the period from point E to point F, and the screen difference may be noticeable.
Therefore, in this embodiment shown in FIG. 3, by utilizing the fact that the correlation of the image in the vertical direction is large, the field obtained from the line correlation based on the odd field data as the even field data during the field image output period. The image is output.

The operation of this embodiment will be described below with reference to FIGS.

In the RAM 3, the odd field data of the still image 1 is written in the period from the point A to the point B. Odd of still image 1 at point B
The field data is read during a period corresponding to one field time (1/60 seconds) from point B to point G and sent to the D / A converter 7 to form a video signal. This data read during this period is set to 1 by the line delay circuit 20 of the signal processing circuit 13.
After being delayed by the line, it is added to the signal of the next line read from RAM3. In this way, the signal for one field, which is the average value of the lines before and after, is written in the RAM 4 in real time via the MPX 11 during the period from point B to point G. At the point G, the data for one field obtained from the line correlation has already been written in the RAM4, so from this point onwards, the MPX6 is in RAM3, until the point D where the even field data of the still image 1 is written in RAM5. Select RAM4 alternately and output one frame of still image. Still image 1 at point D
Since the odd and even field still image data are available, the RAMs 3 and 5 are alternately selected by the MPX6 until the point F, and one frame image is output.

In this way, until the even field data of the still image 1 is written in the RAM 5, the line average field data written in the RAM 4 is used as the even field data instead of the even field data. As a result, there is no left difference between the still image obtained by alternately reading the RAMs 3 and 4 and the still image obtained by alternately reading the RAMs 3 and 5.

Next, another operation of the embodiment shown in FIG. 3 will be described with reference to the timing chart of FIG. This operation is the same as the operation shown in FIG. 5 up to the point F where the data of the odd field of the still image 2 is written in the RAM 2. By the way, when the still image 2 is reproduced from the point F to the point H, this still image 2 is not necessary, so there are times when it is desired to reproduce the next still image. At this time, the correction screen generated by the signal processing circuit 13 is stopped from being continuously sent to the RAM1 by the address control circuit 8, and the subsequent still image 3 is controlled to be written again in the RAM2. Still image is from point B to F
A still image 1 up to the point, a still image 2 from the F point to the H point, a still image 1 from the H point to the I point, and still images 3 and 4 after the I point are sequentially output. As described above, by having a field memory for three fields and creating a corrected image using frame correlation, different still images can be displayed while apparently instantaneously switching.

〔The invention's effect〕

As described above, according to the present invention, different still image signals that are sequentially supplied can be switched to different still image reproduction without interruption, and the capacity of the memory required for the still image reproduction can be reduced. Therefore, it is possible to solve the above-mentioned problems of the conventional technique and provide a still image reproducing device having an excellent function.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a still picture reproducing apparatus according to the present invention, FIG. 2 is a timing chart for explaining its operation, and FIG. 3 is another embodiment of a still picture reproducing apparatus according to the present invention. 4 is a block diagram showing a specific example of the signal processing circuit in FIG. 3, and FIGS. 5 and 6 are timing charts for explaining the operation of the embodiment. 3,4,5 …… RAM 6 …… Multiplexer 7 …… Digital / analog converter 13 …… Signal processing circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Kobayashi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside the Home Appliance Research Laboratory, Hitachi, Ltd. (72) Inventor Shigeru Yamazaki 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa (56) References JP-A-59-51638 (JP, A)

Claims (2)

[Claims] 1. A still image comprising memory means for storing a still image signal in which one frame is composed of two fields reproduced from a recording medium, and the still image signal is read out from the memory means and output. In the reproducing apparatus, the capacity of the memory means is set to 3 fields, and the still image signal is stored in a part of the memory means having a capacity of 2 fields, and each of the 1 field is stored at a reading speed faster than a writing speed.
Alternately and repeatedly read from the field capacity portion, and during this reading, the first field of the new still picture signal to be reproduced next from the recording medium is not read out of the memory means 1 When the data is written in the field capacity portion and the writing of the 1 field capacity portion is completed, the reading of the 1 field capacity portion in place of the 2 field capacity portion at the reading speed is started, and the memory means is also provided. 2. The still image reproducing apparatus, wherein the second field of the new still image signal is written in a portion of 1 field capacity of the portion of 2 field capacity. 2. The correlation between lines from the signal of one field first read from the portion of the one field capacity in which the first field of the new still image signal is written according to claim 1. By using
The third field corresponding to the second field of the new still image signal is generated, and the second field of the new still image signal in the portion of the two-field capacity is written. Writing to a portion of one field capacity other than the portion at a writing speed equal to the reading speed, until the writing of the second field of the still image signal is completed, the first field of the new still image signal and the A still picture reproducing apparatus characterized in that a third field is read out alternately and repeatedly.