JPH0683473B2 - Still image recording method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still image recording method for converting RGB frame-sequential color signals from an image sensor into a magnetic disk standard for electronic still cameras and magnetically recording the signals.

[Prior art]

In recent years, a combination of an image sensor consisting of a solid-state image sensor and a magnetic disk, which is an inexpensive recording medium and has a relatively large storage capacity, is used to record a subject on a rotating disc by purely electronically photographing a subject and reproducing the image. An electronic still camera system has been developed for viewing on this television system.

In this electronic still camera system, the standard of the signal recorded on the magnetic disk is that the primary color signals (R, G, B) of the optical image output from the solid-state image sensor are color difference signals RY, BY.
And the luminance signal Y after being converted, FM recording is performed on each.

On the other hand, the present inventor has previously proposed a solid-state image sensor capable of outputting an image signal in an RGB frame-sequential system and an electronic still camera using this device. In addition, a clear color image was obtained with excellent S / N.

FIG. 2 shows a schematic configuration of the solid-state image sensor and its electronic still camera.

That is, the solid-state image pickup device 2 has a structure in which a micro color filter similar to the photoelectric conversion unit 22 is arranged also on the vertical transfer path 21 of the conventional interline transfer CCD to have a photoelectric conversion function ( In the figure, the array of color filters is conceptually shown by R, G, and B).

Further, a transfer gate 23 is provided between the photoelectric conversion section 22 and the vertical transfer path 21, and the charge of each color accumulated in the vertical transfer path 21 and the photoelectric conversion section 22 is controlled by the opening / closing control of the transfer gate 23. It is selected and vertically transferred by the polysilicon transfer electrode 24. The vertically transferred charge is then transferred to one horizontal
It is output from the CCD 25 via the buffer amplifier 26 as a frame-sequential color signal which is color-separated into R, G and B.

On the other hand, the electronic still camera to which the solid-state image pickup device 2 is applied supplies an area sequential color signal output from the buffer amplifier 26 to the area sequential switching circuit 27 by imaging an object.

The field-sequential switching circuit 27 distributes the output lines to R, G, and B, and supplies the field-sequential color signals corresponding to the magnetic heads 28 connected to the respective output lines. The three magnetic heads 28 are composed of three channels for recording on a magnetic disk 29.

In the recorded magnetic disk 29 on which the image signal is recorded in this manner, 3 tracks are simultaneously reproduced by a dedicated reproducing device having a 3 channel magnetic head. It was possible to obtain an equivalent faithful reproduction color image.

[Problems to be solved by the invention]

However, since the color video signal recorded on the magnetic disk as described above is different from the standard that FM recording the color difference signal and the luminance signal by the electronic still camera system, it is compatible with this. I never happened.

The object of the present invention was made based on the above circumstances,
To provide a still image recording method capable of recording a subject image picked up by this solid-state image pickup device capable of outputting image signals in RGB plane sequential order on a magnetic disk with a signal of a standard standard of an electronic still camera system. It is in.

[Means for solving problems]

That is, the above-mentioned object of the present invention is a still surface image recording method for recording a subject image imaged using a solid-state image sensor which outputs RGB surface sequential color signals on a rotating magnetic disk.
After sequentially recording 3 channels of the B-side sequential color signal in an area outside the standard recording area of the magnetic disk, simultaneously reproducing the 3 channels, and further performing arithmetic processing, FM-modulating the color difference signal and the luminance signal, This is achieved by a static surface image recording method, characterized in that the modulated color difference signal and the luminance signal are added and re-recorded in the standard recording area of the magnetic disk with one magnetic head.

[Action]

The magnetic disk applied to the electronic still camera system is composed of a flexible magnetic disk having a diameter of 47 mm,
A plurality of tracks outside the standard recording area are provided outside the standard recording area on the outermost or innermost side. In the present invention, this nonstandard track is used for buffering, and the frame sequential color signals are temporarily recorded in these tracks and then simultaneously reproduced by the three-channel fixed magnetic head. Further, a color difference signal and a luminance signal are formed from the simultaneously reproduced signals, and these signals are combined to perform one track / one field recording in the standard recording area of the magnetic disk.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 conceptually shows one embodiment of an electronic still camera to which the present invention is applied.

In addition, the solid-state image pickup device described in FIG. 2, that is, the device that outputs RGB surface sequential color signals is used in the image pickup unit of this electronic still camera.

The solid-state image sensor 2 having a subject image formed on the imaging surface through the optical system 1 is scanned based on the horizontal and vertical sync signals from the sync signal generator 3 and is separated into three primary colors R, G, B. The image signals thus generated are output in a frame sequential manner. The image signals output in the frame sequential manner are supplied to the frame sequential switching circuit 4 to distribute the output lines 5 for each of the colors R, G, B, and then correspond to the output lines 5 via the mode switching switch 6, respectively. It is supplied to the 3 channel magnetic head 7.

The three-channel magnetic head 7 is a fixed magnetic head fixed on the outermost three tracks of the magnetic disk 8. Therefore, the solid-state imaging device 2 is included in the three tracks.
The images of the colors R, G, B of one stationary surface, which are output in a frame-sequential manner from the above, are recorded by the three channels 7 respectively.

When a color-separated image of one stationary surface is recorded for each of the three tracks, then the mode switching switch 6 is switched, and the three-channel magnetic head 7 is switched.
Is used as a reproduction head to simultaneously reproduce the three tracks.

The pre-processing unit 9 is supplied with the simultaneously reproduced primary color signals R, G, B, and is amplified to a signal level capable of signal processing, and gamma correction, pedestal insertion, blanking pulse insertion, white level clipping, etc. And outputs the processed primary color signals E _R , E _G , and E _B.

The matrix circuit 10 performs arithmetic processing on the basis of the primary color signals E _R , E _G , and E _B supplied from the preprocessing unit 9 to generate a luminance signal E _Y and color difference signals E _R -E _Y , E _B -E _Y. Occur.

The first FM modulation circuit 11 converts the luminance signal E _Y into a first FM modulated wave in a specific frequency band, and sends the modulated luminance signal to the high pass filter 12.

The second FM modulation circuit 13 outputs the color difference signals E _R -E _Y and E _B -E _Y to the first
Is converted into a second FM modulated wave having a frequency band different from that of the FM modulated wave, and the modulated color difference signal is sent to the low-pass filter 14.

The luminance signal E _Y and the color difference signals E _R -E _Y , E _B -E _Y that have passed through the high-pass filter 12 and the low-pass filter 14 are both supplied to the mixing circuit 15 to be combined and output as a recording signal. .

The recording signal is supplied to the movable magnetic head 17 via the amplifier 16, and one field is re-recorded as a standard signal in one track of the standard recording area of the magnetic disk 17. As a result, one color stationary surface can be recorded in one track.

The track outside the standard recording area is repeatedly used as a buffer track, and the signal for each screen output from the element is repeatedly recorded. The standardized signal is sequentially recorded for each track in the standard recording area.

Although the field recording has been described in the above embodiment, 2
The resolution of the reproduced image is lower than that of frame recording in which one frame of static surface is obtained at the field. Therefore, in order to obtain a high image quality similar to the NTSC signal, a 2-channel magnetic head can be used to record or reproduce an image of one frame by one rotation of the disk.

That is, a field frame conversion circuit for converting a signal using a commonly known 0.5H delay line is inserted in the subsequent stage of the solid-state image sensor, and one frame signal to be output is recorded in two tracks by a two-channel magnetic head. , Can be played.

〔The invention's effect〕

As described above, according to the still image recording method of the present invention, the RGB color signals output in the frame-sequential manner are once recorded and recorded in the track outside the standard recording area of the magnetic disk.
In order to obtain standard signals by extracting RGB signals as simultaneous signals, it is not necessary to digitize each frame sequential signal that is usually considered and store it in memory, and then convert all signals into analog signals. All signals are handled as analog signals. e,
The circuit configuration can be simplified. Also, a digital conversion circuit,
It is possible to avoid an increase in power consumption due to a frame memory etc. and an increase in manufacturing price.

Further, by capturing and recording a subject using a solid-state image sensor capable of outputting a frame sequential color signal, it is possible to record a high-resolution image equivalent to that of the three-panel system.

[Brief description of drawings]

FIG. 1 is a block diagram of an electronic still camera to which an embodiment of the present invention is applied, and FIG. 2 illustrates a field-sequential output solid-state imaging device already proposed by the present inventor and an electronic still camera using the device. FIG. 2 ... Solid-state image sensor, 4 ... Frame sequential switching circuit, 6 ... Mode switching switch, 7 ... 3 channel magnetic head 8 ... Magnetic disk, 17 ... Movable magnetic head

Claims (1)

[Claims] 1. A still image recording method for recording a subject image captured by a solid-state image sensor which outputs RGB surface sequential color signals on a rotating magnetic disk, wherein the signal output from the solid-state image sensor is the standard of a magnetic disk. After sequentially recording 3 channels in an area outside the recording area, simultaneously reproducing the 3 channels, and FM-modulating the color-difference signal and the luminance signal obtained by further processing, and adding the modulated color-difference signal and the luminance signal. And then re-recording in a standard recording area of the magnetic disk with one magnetic head.