JPS6384386A - Electronic still camera - Google Patents

Abstract

PURPOSE:To obtain a still picture with high resolution by recording two time- expanded field signals on two tracks of a rotary magnetic recording medium by two channel heads at the same time. CONSTITUTION:A signal read out of a horizontal CCD 4 is supplied to a field switching means 5 which performs switching at intervals of a 1/2H cycle and distributed to the signals of fields A and B. The signal of the field A which is read out first is supplied to a delay circuit 6 and delayed by 1/2H. Both phase-adjusted signals are timecompressed to a half a normal TV signal, so they are supplied to a time-base correcting circuit 7 and corrected so that their time bases are expanded twice. Both corrected signals are processed normally and then recorded on the fields A and B of a rotating floppy disk 9 through corresponding magnetic heads 9.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an electronic still camera using a frame transfer type CCD, and more specifically, the present invention relates to an electronic still camera using a frame transfer type CCD. This invention relates to an electronic still camera that converts the signal into an equivalent signal and records it on a small-diameter rotating magnetic recording medium.

(Prior art) When a normal frame transfer type C, CD (hereinafter referred to as FTCCD) is used for a movie, it performs 2:1 interlace scanning and outputs a frame signal in which the number of vertical pixels matches the number of TV scanning lines. can.

On the other hand, when this FTCCD is applied to a still camera to capture still images, only a field signal for one screen can be obtained as an output signal from one shot, so the FTCCD
The original resolution of the CCD cannot be fully utilized.

To deal with this, we developed a system in which signal charges are transferred from the CCD light receiving section to the CCD storage section once during one shot exposure in an extremely short period of time, so that the image signals of two fields can be used for image formation. has already been proposed. Exposure is performed continuously during this signal charge transfer, but this transfer period is extremely short compared to the exposure period, so
Even if light hits each light-receiving element of the CCD during signal charge transfer and signal charges corresponding to a shifted image are superimposed, the image quality will not be adversely affected much.

(Problem to be solved by the invention) However, in the above method, if a sufficiently long exposure period cannot be obtained for an extremely short transfer period, for example, when a high-speed shutter is applied, the exposure during the transfer period is Image quality may be adversely affected.

An object of the present invention is to provide an electronic still camera that can obtain clear reproduced still images by taking advantage of the characteristics of FTCCD, without relying on the above-described method.

Another object of the present invention is to provide an electronic still camera in which image signals recorded on a magnetic recording medium can be recorded as standard signals.

(Means and effects for solving the problems) That is, the above object of the present invention is to provide an electronic still camera consisting of a dark box, an imaging optical system, a shutter, and a frame transfer type CCD, in which the frame transfer type CCD increases the number of vertical pixels. It has approximately the same number as TV scanning lines and transfers signal charges in the vertical direction to 1760
field switching means capable of outputting an image signal equivalent to one frame per second, switching the output of the frame transfer CCD every 172H period and distributing it to an A field image signal and a B field image signal; It includes a delay circuit that delays one distributed signal to match the phase with the other, and a time axis correction circuit that doubles the time axis of each phase-aligned A field and B field signal. , the two time-stretched field signals are
This is achieved by an electronic still camera characterized in that a channel head is provided to enable simultaneous recording on two trunks of a rotating magnetic recording medium.

According to the present invention, A obtained by imaging with FTCCD
Field image signals and B-field image signals are recorded as standard signals on two tracks of a rotating magnetic recording medium, and can be reproduced as signals equivalent to frame accumulation obtained by interlaced scanning, making it possible to produce high-resolution still images. can get.

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

FIG. 1 is a diagram showing the main parts of an electronic still camera according to an embodiment of the present invention.

The solid-state imaging device applied to the present invention is an FTCCD.

The FTCCD 1 is placed on an optical path in a dark box, which is not shown for the sake of simplicity, and a subject image is formed on the light receiving section 2 via an imaging optical system and a shutter, which are also not shown. When a signal charge corresponding to the brightness of the subject image is formed in the light receiving section by exposure, this charge is transferred to the storage section 3 during the vertical blanking period, and is further transferred to the storage section 3 corresponding to one scanning line during the horizontal blanking period. horizontal CCD
4 and are sequentially read out as signals.

However, the number of pixels in the vertical direction of the FTCCD 1 is equal to that of the TV.
It consists of the same number of horizontal scanning lines (for example, 488), and the vertical transfer locks PI and PG that drive the light receiving section 2 and the storage section 3 are driven by a double speed clock that is twice the normal speed, which corresponds to frame storage. The signal is set to be output every 1760 seconds. Therefore, at this time, the horizontal CCD 4
From then on, the A field signal and the B field signal are transmitted in accordance with the number of scanning lines every 1/2H period (however, the IH period here is the IH period in the normal NTSC system, which is approximately 63 μsec). are read out alternately.

Even if the sequential signals read out in this manner are recorded as they are, the desired signal, that is, a signal equivalent to interlaced frame accumulation cannot be obtained.

Therefore, in the present invention, the field switching means 5 switches the signal read out from the horizontal CCD 4 every 172H period.
and is distributed into an A field signal and a B field signal. Since there is a phase difference between one of the distributed signals, that is, the A field signal corresponding to the odd rows of the scanning line, and the other signal, that is, the B field signal corresponding to the even rows, the A field that is read out first The field signal is supplied to the delay circuit 6 and delayed by 1/2H.

In addition, the A field and B field signals whose phases are matched by 1/2H delay are 172 times the normal TV signal.
Since it is in a time-compressed form, it is supplied to the time axis correction circuit 7 and corrected so as to extend the time axis twice. The time-axis corrected A field and B field signals are converted into a luminance signal and a color difference signal through normal signal processing, that is, arithmetic processing, and are further FM modulated, and then sent through the respective magnetic heads 8. They are simultaneously recorded on the rotating F1 COSOS disk 9.

On a floppy disk on which image signals have been recorded in this manner, two tracks are simultaneously reproduced by a two-channel head to obtain an interlaced standard signal.

FIG. 2 is a signal waveform diagram illustrating the above process,
In (2), the image signal output from the FTCCD is distributed by the field switching means as shown in (2) and (2), and the field signal is further delayed by 1/2H as shown in (2) and the phases are matched. Furthermore, as shown in (1) and (2), the time axis is expanded and recorded on the floppy disk.

In addition, in the above embodiment, one example of the time axis correction circuit is as follows.
BBD is an analog variable element with a simple structure that has been traditionally used for temporal compression or expansion of audio waveforms.
(bucket brigade device) can be used.

(Effects of the Invention) As described above, according to the electronic still camera of the present invention, since a signal equivalent to frame accumulation is obtained using the FTCCD, a high-resolution still image can be obtained. Furthermore, since the magnetically recorded image signal is recorded as an interlaced standard signal, it can be reproduced on a TV receiver or the like.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram illustrating the main parts of an electronic still camera according to an embodiment of the present invention, and FIG. 2 is a signal waveform diagram illustrating the operation of the camera in FIG. 1. 1...FTCCD, 2...Light receiving section. 3...Accumulation part, 4...Horizontal CCD. 5...Field switching means every 1/2H. 6...Delay circuit, 7...Time base correction circuit. 8...Magnetic head, 9...Floppy disk. Figure 1

Claims (1)

[Claims] Dark box, imaging optical system, shutter and frame transfer type CCD
In an electronic still camera consisting of a frame transfer type C
CD has approximately the same number of vertical pixels as TV scanning lines and 1/
It is possible to output an image signal equivalent to one frame in 60 seconds, and includes field switching means for distributing the output of the frame transfer CCD into an A field image signal and a B field image signal; The time axis correction circuit doubles the time axis of both the phase-aligned A field and B field signals. An electronic still camera characterized in that two field signals can be simultaneously recorded on two tracks of a rotating magnetic recording medium using a two-channel head.