JPH04179381A - Image recorder - Google Patents

Abstract

PURPOSE:To increase the recording speed at the time of a continuous recording without increasing a power consumption by rotating a capstan and a rotary head at the time of the continuous recording mode faster than the time of an independent recording mode, and recording a picture after compressing it at a prescribed compression ratio. CONSTITUTION:In a consecutive photographing mode, a recording signal processing circuit 14 is set in an operational mode for operating a data compression, and a motor driving circuit 32 is set in order to rotate a capstan 28 and a rotary drum 22, for example, at a speed two times as fast as usual. After the mode setting, the recording is started, a video signal is outputted from an image pickup circuit 12, and the recording signal processing circuit 14 temporarily stores this signal in the inside memory. Then, in the consecutive photographing mode, the recording signal processing circuit 14 successively reads out the picture data stored in the inside memory, operated a prescribed compressing processing, outputs the data after operating the addition of an error correction code and a modulation for recording, and successively records the data in a magnetic tape 26. Thus, the high speed continuous recording can be attained without increasing the power consumption at the time of the independent recording.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image recording device, and more specifically to an image recording device that records still images on a tape-shaped recording medium.

[Prior Art] A technique is known in which information signals such as video signals and audio signals are digitally recorded on a magnetic tape housed in a small cassette. In such a magnetic recording/reproducing device, while the transmission system in the device transmits the information signal at a predetermined transmission speed,
Performs signal processing and recording/playback processing.

[Problems to be Solved by the Invention] In the magnetic recording and reproducing device as described above, the signal transmission speed is, for example, approximately 768 bits/sec (= 2 (ch)
If it is set as low as *32 (KHz) *12 (bit)), sufficient image quality can be ensured for recording and reproducing video signals.

However, one frame (3.7Mbit (=640(
It takes about 4.8 seconds to record the video signal of pixel) [,5(YIC)) ).

Therefore, for example, when such a magnetic recording/reproducing device is incorporated into an electronic still camera, the shutter timing is severely restricted, and the snapshot function, which is an important function for a still camera, is also severely restricted. There is.

To shorten the recording time, you can increase the transmission speed mentioned above, but if you constantly increase the tape running speed, etc.
This is undesirable because it increases power consumption and shortens the battery life of electronic still cameras, which are portable devices.

Therefore, it is an object of the present invention to provide an image recording device that eliminates such drawbacks.

[Means for Solving the Problems] An image recording device according to the present invention has an individual recording mode in which a single image is recorded and a continuous recording mode in which a plurality of images are recorded at predetermined time intervals. An image recording device that records still images on a medium, in which the capstan for running the tape-shaped recording medium and the rotary head for recording signals on the tape-shaped recording medium are operated in a continuous recording mode in a manner that is faster than in a single recording mode. It is characterized in that it rotates quickly and compresses and records images at a predetermined compression rate.

[Operation] By the above means, it is possible to increase the recording speed during continuous recording without increasing the power consumption during individual recording, and high-speed continuous shooting recording can be realized.

[Example code] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a block diagram of an embodiment of the present invention. 1
0 is a photographing optical system, 12 is an imaging circuit that converts a subject image into an electrical signal, 14 is a recording signal processing circuit that processes the output of the imaging circuit 12 as a recording signal, 16 is a head switching switch, 1
8.20 is a magnetic head attached to the rotating drum 22 facing 180 degrees, and 24 is a drum motor that rotates the rotating drum 22. 26 is a magnetic tape which is a recording medium, 28 is a capstan, and 30 is a capstan motor that rotates the capstan 28. The rotating tram 22 is mounted obliquely with respect to the longitudinal direction of the magnetic tape 26. 32 is a motor drive circuit that drives the motors 24 and 30; 34 is a system control circuit that controls the entire system; 36 is a snapshot mode setting switch; and 38 is a release switch.

The basic operation of FIG. 1 will be explained. The imaging circuit 12 converts the subject image produced by the photographing optical system 10 into an electrical signal, and outputs the video signal to the recording signal processing circuit 14. The recording signal processing circuit 14 performs D/A conversion and data compression if necessary, adds an error correction code necessary for recording, performs recording modulation, and outputs the result to the switch 16. The switch 16 is controlled by a system control circuit 34, and the output of the recording signal processing circuit 14 is alternately applied to the magnetic head 1 at a predetermined timing.
8 or 20. The system control circuit 34 also drives the drum motor 24 and capstan motor 3° via the motor drive circuit 32, and rotates the rotating drum 24 and capstan 28 at a predetermined speed, as will be described in detail later. The magnetic tape 2 is rotated by the rotation of the capstan 28.
6 runs in its longitudinal direction, and at the same time the rotating drum 22 rotates so that the magnetic heads 18, 20 scan the magnetic tape in a direction oblique to its longitudinal axis. This is a so-called helical scan method. As a result, diagonal tracks 40 as shown in FIG. 1 are sequentially formed.

Next, the characteristic operation of this embodiment will be explained in more detail with reference to the flowchart shown in FIG. When starting, first wait for the release switch 38 to be operated (Sl
). When the release switch 38 is operated, it is determined whether the continuous shooting mode or the single shooting mode is selected based on the state of the continuous shooting mode setting switch 36 (S2).

In the case of single shooting mode, the recording signal processing circuit 14 is set to an operation mode that does not perform data compression, and the capstan 2 is
The motor drive circuit 32 is set to rotate the motor 8 and the rotating drum 22 at a normal speed (S3). In the case of continuous shooting mode, the recording signal processing circuit 14 is set to an operation mode that performs data compression, and the capstan 28 and rotating drum 2 are
The motor drive circuit 32 is set to rotate the motor 2 at twice the normal speed (S4).

After mode setting (S3, 4), recording starts (S
5). That is, a video signal is output from the imaging circuit 12, and the recording signal processing circuit 14 temporarily stores this in an internal memory. For the snapshot mode, the recording signal processing circuit 1
4 sequentially reads the image data stored in the internal memory, performs predetermined compression processing (for example, two-dimensional discrete cosine transform, etc.), adds an error correction code, modulates it for recording, etc., and outputs it. Record on tape 26. In the case of the single copy mode, of course, data is compressed, an error correction code is added, recording modulation, etc. are performed, and the data is sequentially recorded on the magnetic tape 26.

In the snapshot mode, the amount of error correction codes added may be increased.

When the recording of one screen is completed (S6), the quick-shot mode setting switch 36 (s7) is used to finish the single-shot mode, and in the quick-shot mode, as long as the release switch 38 is on (s8). , the process returns to S5 and the recording is repeated.

In this embodiment, the rotating drum 22 and magnetic tape 26 are run at twice the speed during quick copying, so the transmission speed is twice the normal speed. By doubling the transmission speed in this way, it takes approximately 2.4 seconds (=4
．． It can be recorded in 8 seconds * 1/2). To achieve a rapid shooting speed of about 4 frames per second, data compression of about 1/10 is required, but this level of compression is fully achievable by two-dimensional discrete cosine transformation (CCITT Recommendation H261).
). Furthermore, by performing offset sampling for field capture during continuous shooting, the image can be compressed to about 1/4, and rapid shooting of about 2 frames per second can be achieved.

Note that this compression rate may be changed and set depending on the continuous shooting speed.

In addition, in this embodiment, as indicated by diagonal lines in FIG.
p3. The pilot signal of f p4 is recorded, and the continuous shooting record and the single shooting record are recorded, for example, fpl, f p4.
p2゜f p3. When recording in the order of f p4,
Reverse fp4. fp3. f p2. A distinction may be made between the case of recording in the order of f pl and the case of recording in the order of f pl.

Furthermore, when reproducing single-shot recording, the signal can be reproduced without tracking control by increasing the rotational speed of the rotary head and scanning the same track multiple times. When reproducing a snapshot recording, the tape feeding speed is reduced to half that of recording, and the same track is scanned multiple times, so that the signal can be reproduced without tracking control.

[Effects of the Invention] As can be easily understood from the above description, according to the present invention, high-speed continuous recording can be achieved without increasing power consumption during individual recording.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the configuration of an embodiment of the present invention, and FIG. 2 is a flowchart of its operation. 10: Photographing optical system 12: Imaging circuit 14: Recording signal processing circuit 16: Head changeover switch 18.20: Magnetic head 22: Rotating drum 24 Two drum motor
26: Magnetic tape 28: Capstan 30: Capstan motor 32: Motor drive circuit 34 Nisistem control circuit 36: Snapshot mode setting switch 38 Nisylise switch

Claims (1)

[Claims] An image recording device that records still images on a tape-shaped recording medium, and is equipped with an individual recording mode in which a single image is recorded and a continuous recording mode in which multiple images are recorded at predetermined time intervals. , the capstan that runs the tape-shaped recording medium and the rotary head that records signals on the tape-shaped recording medium are rotated faster than in the independent recording mode, and the image is compressed and recorded at a predetermined compression rate. Image recording device.