JPH06189245A - Image recording device - Google Patents

Abstract

PURPOSE:To utilize an existing frame head and also to unnecessitate a memory by reading half of the photoelectric converting signal in an image-pickup part so as to record it, shifting a frame head at high speed after that and reading the remaining photoelectric converting signals in the image pickup part so as to record them in a recording medium. CONSTITUTION:The signal for the portion of two lines within the four lines, that is, the signal of one frame is read by frame-reading as the signal of a first field after exposure. The read signal is recorded and processed by recording signal processing circuits 12A and 12B, impressed on magnetic heads 16A and 16B with recording amplifiers 14A and 14B and simultaneously recorded in different tracks. After the reading of the first field is completed, a system signal generating circuit(SSG) 22 is reset and initialized and also the frame head 16 is shifted at high speed for two tracks so that second reading is started. The signal for two tracks is read out of the reading of the second field and simultaneously recorded in the third and forth tracks.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus, and more particularly to an image recording apparatus using a sampled value analog transmission system.

[0002]

2. Description of the Related Art As an image recording / reproducing apparatus, an electronic still camera system using a magnetic disk called a still video floppy as a recording medium is known. This system is a system in which a television signal is FM-modulated and recorded on a 2-inch magnetic disk, and is hereinafter referred to as an SV system. The present applicant has previously proposed that a still image recording / reproducing system (hereinafter referred to as C
This is called the HSV method. ) Proposed.

A method of processing a luminance signal according to the CHSV method will be described. FIG. 3 shows sample positions on the screen of the luminance signal Y recorded by the CHSV method. The sampling points of the Y signal are offset as shown in FIG.
Sub-sampling and analog transmission are performed in the same manner as the MUSE method for high definition signals. At the time of reproduction, it is returned to the grid-like sample points by the interpolation processing. 65 points per line
0 points (= 1,300 / 2), 500 points in 1 row (= 1,0)
00/2), the information of the sample points included in the lines indicated by A1, A2, ... In FIG. 3 is recorded on one track of the video floppy, and B1, B2 ,.
The information on the sample points included in the line indicated by is recorded on one other track, so that the information on all the sample points on one screen is recorded using a total of four tracks. All tracks are recorded according to the SV recording format. Also, a pulse for matching the sample phase during reproduction is recorded at the same time.

FIG. 4 shows a block diagram of a CHSV type reproducing circuit. The CHSV playback operation will be described with reference to FIG. A magnetic disk 100, which is a still video floppy, is rotated at a predetermined speed by a spindle motor 102, and a signal recorded on the magnetic disk 100 is electromagnetically converted by a magnetic head 104, amplified by a reproducing amplifier 106, and a still image is reproduced.・ Video playback circuit 10
8 is applied. The still video reproducing circuit 108 performs processing such as separation of a luminance component and a color component, FM demodulation and de-emphasis, and the reproduced luminance signal is converted to the gamma reverse conversion circuit 11.
The reproduction color signal is output to the gamma reverse conversion circuit 112. The gamma inverse conversion circuits 110 and 112 perform gamma inverse conversion. The outputs are band-limited by the LPFs 114 and 116, converted into digital signals by the A / D converters 118 and 120, and stored in the image memory 122.

The BPF 124 is the reproduction amplifier 106.
From the output, the frequency-multiplexed pilot signal is extracted at the time of recording, and the sync separation circuit 126 separates the sync signal from the output (reproduction luminance signal) of the LPF 114. The sampling clock generation circuit 128 uses the output of the BPF 124 and the sync signal separated by the sync separation circuit 126 to convert the A / D
A time base corrected sampling clock for the converter 118 is generated, and the sampling clock generation circuit 130 outputs the BPF 124 and the sync separation circuit 1.
A time-axis corrected sampling clock for the A / D converter 120 is generated from the sync signal separated at 26. The address generation circuits 132 and 134 generate write addresses for the image memory 122 according to the sampling clocks output from the sampling clock generation circuits 128 and 130, respectively.

When the above reproducing process is performed for four tracks,
The necessary sample values are stored in the image memory 122, and the image processing circuit 136 performs interpolation processing. The low frequency component Yl of the luminance signal and the color difference signals Cr and Cb are read out from the image memory 122 and converted into RGB signals by the matrix circuit 138. The high frequency component Yh of the luminance signal is also stored in the image memory 122.
Read from the matrix circuit 138 and added to the RGB output signals of the matrix circuit 138 by the adders 140, 142 and 144. The outputs of the adders 140, 142 and 144 are converted into analog signals by the D / A converters 146, 148 and 150, respectively. In this way, the analog RGB output of the reproduction signal is obtained.

The CHSV system uses the sampled value analog transmission system as described above. In brief,
An input analog signal is sampled with a clock of a certain frequency, the sampled value is band-limited, FM-modulated and recorded on a magnetic medium. The signal reproduced from the magnetic medium is FM demodulated, band-limited, and resampled with a clock having the same frequency as that at the time of recording to obtain a sample value signal.

Two conditions must be satisfied in order to obtain a perfect reproduced signal with this method. That is, the first condition is that the sampling clock at the time of reproduction has the correct frequency and the correct phase, that is, sampling is performed under exactly the same conditions as the sampling at the time of recording. The second condition is that, as shown in FIG. 5, the transmission line characteristic is such that the amplitude characteristic is the target roll-off characteristic centered on the frequency fs (= 1 / 2T, T is the pixel interval), and It is a phase (group delay is flat).

In the above-mentioned CHSV system, four tracks are used for recording. The following circuit configuration can be considered as the recording circuit configuration. The first is 4 channels for the magnetic head.
The head is used to divide the output of the image pickup device into four channels and simultaneously record them on a floppy disk. Second
Is a configuration that uses a two-channel frame head and a frame memory as a magnetic head. The first track and the second track record the output signal of the image sensor and directly record it without passing through the memory, On the third and fourth tracks, a signal obtained by recording the output signal of the image pickup device is temporarily stored in the frame memory, and is read and recorded after the movement of the frame head. The third is a configuration using a field head and three field memories. The first track is subjected to a recording process of the output signal of the image pickup element and directly recorded without passing through the memory. On the fourth track, a signal obtained by recording the output signal of the image pickup device is temporarily stored in the corresponding field memory, the field head is sequentially moved, and the stored signal of the corresponding field memory is read and recorded.

[0010]

However, the 4-channel head is not yet practically usable. Since the frame memory or the field memory is used in the second and third configurations, an A / D converter and a D / A converter are required before and after the frame memory or the field memory, resulting in a large-scale circuit. Further, there is a signal that passes through the memory and a signal that does not pass through the memory, and a level difference may occur between these signals.

Therefore, an object of the present invention is to provide an image recording apparatus which eliminates such inconvenience.

[0012]

An image recording apparatus according to the present invention includes an image pickup section, a recording processing section for recording the two signals output from the image pickup section, and a recording processing by the recording processing section. The two-channel frame head that simultaneously records the recorded signals on the recording medium at the same time, reads out half of the photoelectric conversion signals of the imaging unit and records them on the recording medium, and then moves the frame head at high speed to perform imaging. It is characterized in that the remaining photoelectric conversion signals of the set are read and recorded in a recording medium.

[0013]

By the above means, a memory for temporarily storing the photoelectric conversion signal in the image pickup section is not required, so that the circuit can be simplified and can be provided at a low cost. Further, since the signals recorded on different tracks pass through the same processing system, there is no difference in signal level between tracks.

[0014]

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

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. Reference numeral 10 denotes an image pickup unit, which has two image pickup systems 10A and 1A.
With 0B. 12A and 12B are the imaging system 10 respectively.
A recording signal processing circuit for the output signals of A and 10B, 14
A and 14B are recording amplifiers, 16 is a magnetic head 16A, 1
6B is a frame head, 18 is a magnetic disk as a recording medium, 20 is a system control circuit for controlling the whole, and 22 is a drive pulse for the imaging systems 10A and 10B of the imaging unit 10 under the control of the system control circuit 20. Is a system signal generation circuit (SSG) for supplying the.

FIG. 2 shows an operation flowchart of the circuit of FIG. 1, and FIG. 6 shows a timing chart. The operation will be described with reference to FIGS.

First, the quick return mirror (hereinafter abbreviated as QRM) is retracted in the image pickup section 10 (S1), a clear signal is applied to the image pickup element (S2), and unnecessary charges are removed (CLEAR1, 2). ). Then, the photometric and colorimetric operations are performed, and the shutter speed is set (S
3) Then, the shutter is released to expose the image sensor for a predetermined period (S4).

After exposure, a signal for 2 lines out of 4 lines, that is, a signal for 1 frame is read out by frame reading as a signal of the first field (S5, 6).
The reason why frame reading is used is that when existing elements are used for the image sensor and SSG, field reading causes reading as upper and lower addition average data. The read signals are recorded signal processing circuits 12A, 12
The recording process is performed by B, is applied to the magnetic heads 16A and 16B via the recording amplifiers 14A and 14B, and is simultaneously recorded on different tracks.

When the reading of the first field is completed (S7), the SSG 22 is reset and initialized (S8), and the head 16 is moved at high speed to the positions of two tracks, that is, the positions of the third and fourth tracks (S14). ). During the head movement, the read data set is performed again (S9), and the second read is started (S1).
0). At this time, the field shift pulse for shifting the charge from the photodiode to the charge transfer path is masked to invalidate the reading of the first field. In this case, no signal is output from the image sensor even if the SSG 22 is operating. In this way, the signals for two tracks are read out as valid from the reading of the second field, and are simultaneously recorded on the third and fourth tracks.

When the reading of the second field is completed (S11), the head 16 is moved by two tracks (S1).
2) Return QRM (S13).

By the above operation, the field memory and the frame memory become unnecessary. However, although the S / N of the signal at the time of the second read is deteriorated due to the delay of the read, in the present embodiment, there is no problem experimentally because it is two vertical synchronization periods (about 33 ms).

In the above embodiment, the existing image sensor and SS
Since G is used, there is a limitation in the signal reading method. However, by changing the setting of the second reading position, reading from the second field or reading the field reading method as it is instead of the upper and lower averages is performed. By doing so, one vertical synchronization period (about 16.7 ms) can be provided between the first field and the second field, and the S / N can be improved. Further, the head movement speed at that time is set so that the movement is completed within two vertical synchronization periods in the above example, but high-speed movement within one vertical synchronization period can be technically sufficiently realized.

The case of 4-track recording has been described, but the present invention can be applied to the case of frame recording by a field head.

[0024]

As can be easily understood from the above description, according to the present invention, the circuit can be made simple and inexpensive by utilizing the existing frame head and eliminating the need for the memory. Further, since the signals to be recorded on the different tracks pass through the same processing system, there is an advantage that no signal level difference between the tracks occurs.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is an operation flowchart of FIG.

FIG. 3 is an explanatory diagram of sampling positions of a CHSV type luminance signal.

FIG. 4 is a basic configuration block diagram of a CHSV type reproduction system.

FIG. 5 is a transmission line characteristic of a sampled value analog transmission system.

FIG. 6 is a timing diagram of FIG. 1.

[Explanation of symbols]

10: Imaging unit 10A, 10B: Imaging system 12A, 12
B: Recording signal processing circuit 14A, 14B: Recording amplifier 16: Frame head 16A, 16B: Magnetic head 20: System control circuit 22: System signal generation circuit (SSG)

Claims (1)

[Claims] 1. An imaging unit and 2 output from the imaging unit
It comprises a recording processing means for recording each of the two signals and a two-channel frame head for simultaneously recording the signals recorded by the recording processing means on a recording medium, and reads out half of the photoelectric conversion signals of the image pickup section. The image recording apparatus is characterized in that the frame head is moved at a high speed, the remaining photoelectric conversion signals of the image pickup section are read out and recorded on the recording medium.