JP2625732B2 - Playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a playback apparatus, and more particularly, to a playback apparatus suitable for an electronic still camera.

[Conventional technology]

The electronic still camera must be capable of reproducing and displaying the recorded image immediately, that is, without performing development and printing processes as in the case of a silver halide film, and that it can be transmitted to a remote location via a transmission path. It has such features. Therefore, there has been proposed an electronic still camera in which an image display device, a so-called electronic view finder (EVF), and a playback function are added to the electronic still camera itself. In order to accurately observe the recorded color image, it is preferable that the EVF is color-compatible. FIG. 4 shows a block diagram of an electronic still camera with a reproduction function.

In FIG. 4, at the time of recording, the light beam that has passed through the photographing lens 10 is applied to the image pickup surface of the image pickup circuit 12, and
Outputs color signals of R, G, and B of the subject. The process circuit 14 forms a luminance signal Y and two color difference signals RY and BY from the R, G and B signals, and the color difference signals are line-sequentialized by a switch 16. The FM modulation circuit 18 is
FM signal from the luminance signal from the
FM modulation of the color difference line sequential signal from. The recording circuit 22, FM
Receiving an output C _FM output Y _FM and the FM modulation circuit 20 of the modulation circuit 18, frequency multiplexing, subjected to a known treatment for other recording is applied to the head 26 mounting a recording via the switch 24. Thus, an image signal is recorded on the magnetic disk 28.

At the time of reproduction, the signal reproduced from the magnetic disk 28 is
The signal is supplied to the reproduction circuit 30 via the head 26 and the switch 24, and the output of the reproduction circuit 30 is supplied to the Y / C separation circuit 32. Y
The / C separation circuit 32 separates Y _FM and C _FM, and the FM demodulation circuit 34
_{The FM} signal is demodulated and a luminance signal is output.
Demodulates _FM signal and outputs color difference line sequential signal. The line synchronization circuit 38 synchronizes the line-sequential signal output from the FM demodulation circuit 36. That is, the line synchronizing circuit 38 includes a 1H (horizontal scanning period) delay line 40 and two changeover switches 41 and 42.
Two color difference signals of Y and BY are output. The matrix circuit 44 forms R, G, B signals from the luminance signal and the two color difference signals. The output of the matrix circuit 44 is supplied to an electronic viewfinder (EVF) 4 via switches 45, 46, and 47 that are switched between recording (REC) (or shooting) and playback (PB).
Applied to 8.

The other contacts of the changeover switches 45, 46, 47 are connected to the output of the imaging circuit 12, so that the switches 45, 46, 47 are connected to the imaging circuit 12
By switching to the side, the image pickup circuit (or recorded image) by the image pickup circuit 12 can be observed by the EVF 48.

[Problems to be solved by the invention]

As described above, in the conventional electronic still camera, the color difference signals are line-sequentially recorded during recording and synchronized during reproduction, so that a line synchronization circuit, specifically, a 1H delay line, is used for displaying a reproduced image. Is required. In order for electronic still cameras to become widespread, it is essential to reduce the price. Use of such a delay line is not preferable because it increases the circuit scale and the price.

Accordingly, the present invention provides a reproducing apparatus that can reproduce a color image signal recorded on a recording medium while securing image quality that does not visually impair, without using a 1H delay line as in the conventional example. It is intended to be presented.

[Means for Solving the Problems] The reproducing apparatus according to the present invention provides a color image signal including a line-sequential color difference signal formed by line-sequencing a first color difference signal and a second color difference signal. A reproducing apparatus for reproducing the color image signal from a recorded recording medium, reproducing a signal recorded on the recording medium, and extracting a line-sequential color difference signal included in the reproduced signal. And a line-sequential color difference signal extracting means for outputting, and a line-sequential color difference signal output from the line-sequential color difference signal extracting means and a signal having a first level. 1 in the line-sequential color difference signal and the second color difference signal and the signal having the first level.
A first signal output unit that alternately outputs a period corresponding to a switching cycle of the color difference signal, a line sequential color difference signal output from the line sequential color difference signal extraction unit, and a signal having a second level. A switching cycle of a first color difference signal and a second color difference signal in the line-sequential color difference signal between a second color difference signal of the input line-sequential color difference signals and a signal having the second level. And a second signal output means for alternately outputting the signal every period corresponding to.

[Action]

According to the above-described configuration, a color image signal reproduced from a recording medium can be output in a substantially accurate color reproduction state without significantly disturbing the overall color balance.

〔Example〕

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

FIG. 1 is a configuration block diagram of one embodiment. The same components as those in FIG. 4 are denoted by the same reference numerals.

In FIG. 1, 50 is a constant voltage source for generating a DC voltage equal to the central potential of the RY signal, 52 is a constant voltage source for generating a DC voltage equal to the central potential of the BY signal, and 54 and 56 are 1H. A changeover switch that switches according to the LALT pulse that changes every time,
58 is an amplifier. The operation at the time of recording is the same as that in the case of FIG. 4, and the description is omitted. During reproduction (PB), during the RY period of the color difference line sequential signal demodulated by the FM demodulation circuit 36, the switch 54 is connected to the amplifier 58 side, and the switch 56 is connected to the constant voltage source.
On the other hand, during the BY period, the switch 54 is connected to the side of the constant voltage source 50, and the switch 56 is connected to the side of the amplifier 58.

That is, the R of the color difference line sequential signal demodulated by the FM demodulation circuit 36
In the -Y period, the demodulated color difference signal is input to the RY input of the matrix circuit 44, and the B-Y input is the B-Y input.
A DC voltage equal to the center potential of the Y signal is input. On the other hand, during the BY period, a demodulated color difference signal is input to the BY input of the matrix circuit 44, and a DC voltage equal to the central potential of the RY signal is input to the RY input. . This is shown in FIG. 2 (a) shows the waveform of the color difference line sequential signal output from the FM demodulation circuit 36, FIG. 2 (b) shows the signal waveform applied to the RY input of the matrix circuit 44, and FIG. Is B- of the matrix circuit 44.
3 shows a signal waveform applied to a Y input. If the output of the FM demodulation circuit 36 is supplied to the matrix circuit 44 at the same amplitude, the color signal intensity of the entire screen becomes insufficient. To compensate for this, the amplifier 58 amplifies the signal by a predetermined amount.

In this configuration, the color signal output for each horizontal period is not accurate, but a correct color can be reproduced by averaging every 2H period. With a display element having a low vertical resolution such as the EVF48, a reproduced image can be observed with appropriate color reproduction.

In the embodiment shown in FIG. 1, the R, G, B signal output of the imaging circuit 12 and the output of the matrix circuit 44 can be switched freely, but at the stage of the luminance signal and the color difference line sequential signal which are the outputs of the process circuit 14. It may be switchable. FIG. 3 shows a second embodiment thereof. That is, reference numeral 60 denotes a switch that switches between a luminance signal output from the process circuit 14 and a luminance signal output from the FM demodulation circuit 34 and selectively supplies the luminance signal to the matrix circuit 44, and 62 denotes a switch 16 And a switch for switching between a color difference line-sequential signal of the FM demodulation circuit 36 and a reproduced color difference line-sequential signal output from the FM demodulation circuit 36. The output of the switch 60 is amplified by the amplifier 64 and supplied to the RY input terminal or the BY input terminal of the matrix circuit 44 via the switches 66 and 68. 70 and 72 are constant voltage sources. The amplifier 64, the switches 66, 68, and the constant voltage sources 70, 72 perform the same operations as the amplifier 58, the switches 54, 56, and the constant voltage sources 50, 52 in FIG.

In the embodiment of FIG. 3, the output amplitudes of the FM demodulation circuits 34 and 36 are set to F
Since the adjustment may be performed so as to be equal to the input amplitude of the M modulation circuits 18 and 20, there is an advantage that the adjustment becomes easy.

〔The invention's effect〕

As can be easily understood from the above description, according to the present invention, even if the line-sequential color difference signal synchronizing circuit including the 1H delay line and the like is not provided, the same as when the line-sequential color difference signal synchronizing circuit is provided. A reproduced color image signal can be obtained, which can contribute to a reduction in circuit scale and cost.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of one embodiment of the present invention, FIG. 2 is a waveform diagram of FIG. 1, FIG. 3 is a block diagram showing a configuration of another embodiment of the present invention, and FIG. It is a block diagram. 16 ... Changeover switch for line sequentialization, 28 ... Line synchronization circuit, 40 ... 1H delay line, 50,52,70,72 ... Constant voltage source

Claims (1)

(57) [Claims] A first color difference signal and a second color difference signal, which are line-sequentially converted from a recording medium on which a color image signal including a line-sequential color difference signal is recorded. A reproducing apparatus for reproducing, reproducing a signal recorded on the recording medium, extracting a line sequential color difference signal included in the reproduced signal, and outputting the line sequential color difference signal extracting means; A line-sequential color difference signal output from the sequential color-difference signal extracting means and a signal having a first level are input, and a first color difference signal of the input line-sequential color difference signals and a signal having the first level A signal output means for alternately outputting the first color difference signal and the second color difference signal in the line-sequential color difference signal in a period corresponding to a switching cycle of the first color difference signal; Line sequential color difference No. and inputs the signal having the second level, first in the second of said sequential color difference signal and a signal having the color difference signal of the second level of the input line sequential color difference signals
A second signal output means for alternately outputting the color difference signal and the second color difference signal in a period corresponding to a switching cycle of the second color difference signal. A playback device comprising: