JPH04255188A - Still picture signal generator - Google Patents

Abstract

PURPOSE:To surely output an original reproduction signal when a video signal recorded on a magnetic disk in terms of fields to a video printer. CONSTITUTION:Switches 13, 14 are controlled by a control signal S3 from a terminal 16. An output signal of an FM demodulator 4 is outputted from an output terminal 22 via a switch 19 as an original reproduction signal. Moreover, the output signal of the FM demodulator 4 is fed to a 1/2 delay circuit 18 via the switch 14 and delayed by 1/2H only. An output signal of the 1/2 delay circuit 18 is outputted from the output terminal 22 via the switch 15 as a signal resulting from the original reproduction signal delayed by 1/2H only. Furthermore, since the switch 15 and the switch 19 are alternately turned on/off, the original reproduction signal and the signal resulting from delaying the original reproduction signal by 1/2H are outputted from the output terminal alternately.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still image signal generating device applied to, for example, a magnetic disk reproducing device.

0002

2. Description of the Related Art Color video signals of the NTSC system are: 1.
By performing 262.5 horizontal scans in one field period of 001/60 seconds, and filling in the middle of the adjacent scan lines scanned in the previous field with 262.5 scan lines in the next one field period. It constitutes one image (frame).

Electronic still cameras have been put into practical use that record NTSC still image signals on small magnetic disks and reproduce the still image signals from the magnetic disks. With this electronic still camera, one track of the disc has 262.5
There are a field recording mode in which lines are recorded and a frame recording mode in which one frame of still image is recorded using two tracks. When playing back images recorded in field recording mode, interpolation processing is performed so that a more natural still image can be viewed. This outputs one field of video signal played from the disc as it is, and in the next field,
This is a video signal formed by processing the contents of adjacent lines by arithmetic averaging, etc., and fills in the gaps between the lines of the previous field. Here, a signal formed by interpolation from an original video signal reproduced from a disc will be referred to as an interpolated video signal.

0004

On the other hand, video printers that print video signals are known, but there are frame printers that print all 525 lines and field printers that print only half of the information. When outputting an image field-recorded by the above-mentioned electronic still camera, it is not determined whether the odd field or the even field should be output as an interpolated video signal. Therefore, when an output signal from such an electronic still camera is input to a field printer, there is a probability of 1/2 that an interpolated video signal will be printed. Since the interpolated video signal is an auxiliary signal and has a lower resolution than the original video signal, there is a problem in that the quality of the hard copy obtained by printing the interpolated video signal is poor.

[0005] Accordingly, an object of the present invention is to provide a still image signal generating device having a mode that can reliably output an original video signal when outputting a field recorded video signal.

[0006]

SUMMARY OF THE INVENTION The present invention provides a still image signal consisting of a first video signal of a first field and a second video signal of a second field formed from the first video signal. In the still image signal generating device, a video signal reproducing means for outputting a first video signal;
means for forming the second video signal from the first video signal; a mode for alternately outputting the first video signal and the second video signal; and a mode for outputting only the first video signal. 1 is a still image signal generating device comprising means for selecting a still image signal;

[0007]

[Operation] A control signal for output switching during field reproduction is supplied from the terminal 16 to the switch 13 and the switch 14. The original video signal from the FM demodulator 4 is outputted as an original video signal from the output terminal 22 via the switch 19. Further, the original video signal from the FM demodulator 4 is transmitted to the switch 14.
The signal is supplied to the 1/2H delay circuit 18 via the 1/2H delay circuit 18. The original video signal is delayed by 1/2H and output from the output terminal 22 via the switch 15. The original video signal and a signal obtained by delaying the original video signal by 1/2H are alternately outputted from the output terminal 22. Therefore, when an output signal is supplied to a video printer to obtain a hard copy, deterioration in the image quality of the hard copy can be prevented no matter which signal is used.

[0008]

[Embodiment] The structure of an embodiment of the present invention will be explained below.
This will be explained with reference to the drawings. In FIG. 1, for example, a large number of tracks are formed concentrically, and one track is formed in each track.
A magnetic disk on which field video signals are recorded. This magnetic disk 1 is rotated at a field frequency. Magnetic heads H1 and H are installed so that two adjacent tracks can be respectively reproduced on the magnetic disk 1.
2 is provided.

Signals reproduced from the magnetic disk 1 by the magnetic heads H1 and H2 are supplied to an inner-circumference reproducing amplifier 2 and an outer-circumferential reproducing amplifier 3, respectively. The signals amplified by the inner frequency reproducing amplifier 2 and the outer frequency reproducing amplifier 3 are subjected to FM demodulation by the FM demodulator 4 via the switch 8 and the switch 10, respectively. Switch 8 and switch 10 are turned on/off by N.
It is controlled by the output signal S1 of the OR gate 7. That is, the output signals of the terminals 5 and 6 are supplied to the NOR gate 7, and the output signal S1 of the NOR gate 7 causes the switch 8 to be
is controlled. Further, the signal S1 is inverted by an inverter 9, and the switch 10 is controlled by the output of the inverter 9. Terminal 5 is an input terminal for a control signal for frame/field reproduction switching, and terminal 6 is an input terminal for field switch pulses.

The output signal of the FM demodulator 4 is sent to the 1H delay circuit 1.
1 (H is the horizontal scanning period) and is supplied to the adder circuit 12. The output signal of the 1H delay circuit 11 is added to the original video signal by the adder circuit 12. The adder circuit 12 halves two input signals or output signals. The output signal of the adder circuit 12 is supplied to the 1/2H delay circuit 18 via the switch 13. At the same time, the output signal of the FM demodulator 4 is supplied to the 1/2H delay circuit 18 via the switch 14. The output signal of the FM demodulator 4 is taken out to the output terminal 22 via the switch 19. The switch 13 is controlled by a control signal S3 from the input terminal 16. Also,
Control signal S3 is inverted by inverter 17, and switch 14 is controlled by the output of inverter 17. This control signal S3 is a control signal for output switching, and is formed by a user's switch operation, for example. This control signal S3 controls on/off of the printer output.

The output signal of the 1/2H delay circuit 18 is taken out to the output terminal 22 via the switch 15. Note that the switch 15 and the switch 19 are controlled by the output signal S2 of the NAND gate 20. Switch 19 is controlled by signal S2. Also, the output signal S2 is output from the inverter 2
1, and the switch 15 is controlled by the output of the inverter 21.

The operation of one embodiment of the present invention will be explained below with reference to the drawings. There are three types of output modes in one embodiment of this invention. That is, when the printer output is turned on during field playback, that is, a video printer or the like is connected to the output terminal 22, when the printer output is turned off during field playback, that is, when a television monitor is connected to the output terminal 22, and This is the case during frame playback.

FIG. 2 shows waveforms during field reproduction in which only the reproduction signal of the magnetic head H2 is used. During field playback, when the printer output is on, the output signal S10 of terminal 5 is at a high level (hereinafter referred to as H).
(Fig. 2A). The output signal S20 of the terminal 6 is a signal whose low level (hereinafter referred to as L) and H are inverted every field period in synchronization with the reproduction signal (Fig. 2B
). When the signal S10 is H and the signal S20 is L or H, the signal S1 is always L (FIG. 2C). Switch 8 is the signal S
1 (FIG. 2D). Along with this, the signal S1
is inverted by the inverter 9, the switch 10 is turned on (FIG. 2E). As a result, the reproduction signal of the disc 1 is amplified by the outer peripheral reproduction amplifier 3, and the switch 10
The signal is supplied to the FM demodulator 4 via the FM demodulator 4.

Further, when the signal S10 is H and the signal S20 is L or H, the signal S2 becomes L between Ta and H between Tb (FIG. 2F). The switch 19 is turned off between Ta and turned on between Tb by the signal S2 (FIG. 2H). Along with this,
Signal S2 is inverted by inverter 21. The switch 15 is turned on between Ta and turned off between Tb by the output signal of the inverter 21 (FIG. 2G).

On the other hand, when the printer output is on,
The control signal S3 is set to L (FIG. 2I), and the switch 13 is turned off (FIG. 2J). At the same time, the control signal S3 is inverted by the inverter 17, and the switch 14 is turned on (FIG. 2K). Therefore, the output signal of the FM demodulator 4 is passed through the switch 14 and supplied to the 1/2H delay circuit 18. Further, the output signal of the FM demodulator 4 is outputted from the output terminal 22 via the switch 19. 1/2H delay circuit 18
The signal supplied to the video signal is delayed by 1/2H compared to the original video signal and is output from the output terminal 22 via the switch 15.

Here, the switch 15 and the switch 19 are alternately turned on and off. That is, for example, the switch 15 is turned on between Ta, and the 1/2H delay circuit 18
The original video signal delayed by 2H is output from the terminal 22 via the switch 15. Between Tb and Tb, the switch 19 is turned on and the original video signal is output from the output terminal 22.

Therefore, when a field printer is connected to the output terminal 22, the original reproduction signal is outputted from the output terminal 22 via the switch 19 in the first field.
In the second field, a signal obtained by delaying the original reproduction signal by 1/2H is outputted from the output terminal 22 via the switch 15.

When the printer output is off during field reproduction, the output signals of S1 and S2 are the same as in the case of field reproduction described above. However, when the printer output is off, the control signal S3 at the terminal 16 is set to H, and the switch 13 is turned on. Along with this, the control signal S
3 is inverted by the inverter 17, and the switch 14 is turned off. Therefore, the output signal of the FM demodulator 4 is 1H
The signal is supplied to the delay circuit 11. The output signal of the FM demodulator 4 and the output signal of the 1H delay circuit 11 are added by an adder circuit 12. At the same time, the output signal of the FM demodulator 4 is outputted from the output terminal 22 via the switch 19 as an original video signal. The output signal of the adder circuit 12 is sent to the 1/2 delay circuit 1.
8 and is outputted from an output terminal 22 as an interpolated video signal via a switch 15. Here, switch 1
5 and switch 19 are turned on and off alternately. That is, the switch 15 is turned on between Ta, and the interpolated video signal that has been subjected to processing such as arithmetic averaging is outputted from the terminal 22 via the switch 15. Also, switch 19 between Tb
is turned on, and the original video signal is output from the output terminal 22 via the switch 19.

Therefore, when the printer output is off during field reproduction, the original video signal is output from the output terminal 22 via the switch 19 in the first field. In the second field, the interpolated video signal is outputted from the output terminal 22 via the switch 15.

During frame reproduction, the signal S10 is set to L (FIG. 3A), and the L and H levels of the signal S20 are inverted every field period (FIG. 3B). In other words, the signal S20 is Ta
H between Tb and L between Tb and Tb. Signal S10 is L and signal S2
When 0 is L or H, the signal S1 is L between Ta and H between Tb (FIG. 3C). When the signal S1 is L, the switch 8 is turned off (FIG. 3D). Further, the signal S1 is inverted by the inverter 9, becomes H, and the switch 10 is turned on (FIG. 3E). In this way, switch 8 and switch 10
are turned on and off alternately. As a result, the inner frequency reproduction amplifier 2 and the outer frequency reproduction amplifier 3 amplify the signal from the disk 1. The output signals of the inner frequency regeneration amplifier 2 and the outer frequency regeneration amplifier 3 are as follows.
The signal is alternately supplied to the FM demodulator 4 by turning the switches 8 and 10 on and off.

Further, when the signal S10 is L and the signal S20 is L or H, the signal S2 is always set to H (FIG. 3F). Therefore, switch 15 is turned off (FIG. 3G) and switch 19
is turned on (FIG. 3H). In addition, when playing frames,
Control signal S3 has no effect. Therefore, when a frame printer or television monitor is connected to the output terminal 22 during frame playback, the original playback signal is output to the switch 1 in the first field and the second field.
The signal is outputted from the output terminal 22 via the signal line 9.

[0022]

Effects of the Invention As explained above, the still image signal generation device of the present invention does not perform arithmetic averaging processing of the upper and lower lines in creating an interpolation signal when the printer output is turned on during field playback. , outputs the original video signal and a signal delayed by 1/2 of the original video signal. Therefore, when a field printer prints an image field-recorded on a magnetic disk, it is possible to reliably print the original video signal, that is, a signal with no reduction in resolution.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a still image signal generation device according to the present invention.

FIG. 2 is a waveform diagram during field playback.

FIG. 3 is a waveform diagram during frame playback.

[Explanation of symbols]

13 Switch 14 Switch 16 Terminal 17 Inverter

Claims (1)

[Claims] 1. A still image signal generating device that generates a still image signal consisting of a first video signal of a first field and a second video signal of a second field formed from the first video signal. a video signal reproducing means for outputting the first video signal; a means for forming the second video signal from the first video signal; and a means for forming the second video signal from the first video signal; A still image signal generating device comprising means for selecting a mode in which the video signal is output alternately and a mode in which only the first video signal is output.