JPH01311684A - Image reproducing device - Google Patents

Abstract

PURPOSE:To obtain an image signal with amplitude desirable for print by performing the automatic adjustment of the contrast of a reproducing image signal based on the level of the video part of the image signal. CONSTITUTION:The output of a luminance signal processing circuit 18 is impressed on an AGC circuit 22, and a synchronizing signal elimination circuit 34 eliminates a synchronizing signal, and impresses the signal of the image part on a video level detection circuit 36 and a VCA(voltage controlled amplifier)38. The VCA 38 amplifies the signal of the image part from the synchronizing signal elimination circuit 34 by a gain controlled by a mean level detected at the video level detection circuit 36, and synthesizes it with the synchronizing signal separated at the synchronizing signal elimination circuit 34. In such a way, it is possible to obtain a video signal automatically adjusted to the contrast suitable for the print and to reduce test printing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image reproducing device, and more specifically to an image reproducing device that outputs a video signal suitable for printing.

[Conventional technology]

When trying to print an image from a video signal, inputting the video signal as is to an image printer results in an overall dark image.To avoid this, conventionally, the fourth
As shown in the figure, a video signal source 70 (for example, a video playback device or still video playback device using an optical disk, magneto-optical disk, magnetic tape, etc.) and an image printer 7
A level adjustment circuit 74 is provided between the two, and the contrast of the output video signal from the video signal source 70 is manually adjusted by the level adjustment circuit 74.

Taking as an example a still video playback device that uses a so-called still video floppy as a recording medium as the video signal source 10, the playback output is 100% white as shown in FIG. 5(a).
Since the peak-to-peak ratio of χ is set to 1 [■], the actual image will have a value much smaller than 1 [v, a], as shown in Figure 5(b), for example. . When this is applied to a television receiver, color development is not a major problem, but when printed, the image becomes very dark. Therefore, level adjustment circuit 1
4, the contrast is increased and the waveform of FIG. 5(b) is changed to the waveform of FIG. 5(C).

[Problem to be solved by the invention]

However, in the conventional configuration in which the contrast is manually adjusted, there is a drawback that it is impossible to know whether the contrast is appropriate, that is, optimal, until printing is performed. In other words, multiple test prints are unavoidable.

Further, the contrast must be readjusted each time an image is to be printed, which is inconvenient.

Therefore, it is an object of the present invention to provide an image reproducing device that eliminates these drawbacks.

[Means to solve the problem]

An image reproducing apparatus according to the present invention is an image reproducing apparatus that reproduces an image signal from an image recording medium, and includes means for automatically adjusting the contrast of the reproduced image signal based on the average level of the video portion of the image signal. It is characterized by having been provided.

[Effect]

By providing the above adjustment means, it is possible to obtain an image signal with a preferable amplitude for printing based on the average level. Therefore, there is no need for manual adjustment.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a configuration block diagram of an embodiment of the present invention when applied to a still video playback device.

10 is a still video floppy; 12 is a spindle motor that rotationally drives the floor heater 1.0; 14
16 is a reproduction head, 16 is a reproduction amplifier, 18 is a luminance signal processing circuit that processes the luminance component of the reproduction signal, and 20 is a color signal processing circuit that processes the color component of the reproduction signal. Luminance signal processing circuit 18 and color signal processing circuit 2
0 is, for example, a filter for extracting each signal component,
This is a well-known circuit that includes an equalizer, a limiter, a de-emphasis circuit, etc., and outputs a luminance signal Y and color difference signals RY and BY, respectively. 22 is an AGC (auto gain controller) that automatically controls the contrast of the luminance signal output from the luminance signal processing circuit 18, although the details will be described later.
24 is an NTSC encoder that forms a black signal C from the color difference signals R-Y and B-Y output from the color signal processing circuit 20; 26 is a mixing circuit for superimposing characters, etc. .

Further, 28 is a low bus filter (LPF) that separates the ID (index) signal from the output of the reproduction amplifier 16.
, 30 is an ID detection circuit that detects the ID from the output of the LPF 28, and 32 is a system controller that controls the entire system.

In the AGC circuit 22, 34 is a sync signal removal circuit that removes the sync signal from the input luminance signal and outputs an image portion signal, and 36 is a sync signal removal circuit that detects the average level of the image portion signal output from the sync signal removal circuit 34. The video level detection circuit 38 is a voltage controlled amplifier (VCA) that amplifies the image partial signal output from the synchronization signal removal circuit 34 under gain control by the output of the video level detection circuit 36.

In this embodiment, the VCA 38 also has a function of synthesizing the synchronization signals removed by the synchronization signal removal circuit 34. 40 is the output of VCA38 (i.e. AGC output) and AG
This is a selection switch that selects the output of the brightness signal processing circuit 18 before C, and is switched and controlled by the control signal 42. That is, when connecting to a television receiver, the switch 40 is connected to the a contact side, and when connecting to a printing device such as a printer, it is connected to the b contact side.

First, I will briefly explain the playback operation of floppy 10.
Under the control of system controller 32, motor 12 rotates at a predetermined speed. Then, the recording signal of the designated track is reproduced by the magnetic head 14, and the output of the head 14 is amplified by the reproduction amplifier 16 and applied to the luminance signal processing circuit 18, the color signal processing circuit 20, and the LPF 3B. The luminance signal processing circuit 18 extracts the luminance signal component, performs known signal processing on it, and outputs it.The chrominance signal processing circuit 20 extracts the chrominance component and converts it into a color difference signal under the synchronization signal from the luminance signal processing circuit 18. Output R-Y and B-Y.

In addition, the LPF3B takes out the ID signal and detects the ■detection circuit 3.
0 and the ID detected by the ID detection circuit 30 is applied to the system controller 32 and decoded.

The output of the luminance signal processing circuit 18 is applied to the AGC circuit 22. The synchronization signal removal circuit 34 removes the synchronization signal,
The signal of the image part is sent to the video L/bell detection circuit 36 and VCA.
38. The video level detection circuit 36 detects the average level of the image portion. The VCA 38 amplifies the image portion signal from the synchronization signal removal circuit 34 with a gain controlled by the average level detected by the video level detection circuit 3G. The VCA 38 also synthesizes the synchronization signals separated by the synchronization signal removal circuit 34. Therefore, the output of the VCA 3B has the same signal format as a normal luminance signal. V
The output of CA3B is applied to mixing circuit 26 via switch 40.

A reproduction ID signal and a character signal are applied from the system controller 32 to the mixing circuit 26.
superimposes these on the luminance signal output of the AGC circuit 22.

It is conceivable to provide the AGC circuit 22 on the printer side, but in that case, it would not be possible to superimpose the video signal first.

In the embodiment shown in FIG. 1, AGC processing is performed only on the luminance signal, but even if AGC circuits 44 and 46 are provided for the color signal as shown in FIG. 2, as shown in FIG. AGC circuits 48, 50, 52 may be provided for both the luminance signal and the chrominance signal.

〔Effect of the invention〕

As can be easily understood from the above description, according to the present invention, a video signal whose contrast is automatically adjusted to be suitable for printing can be obtained. Therefore, it is possible to significantly reduce the number of test prints, and it is possible to print with image quality that is higher than that which can be obtained as is, so that the labor of manual adjustment can be saved, and the labor of printing can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the configuration of one embodiment of the present invention, FIGS. 2 and 3 are block diagrams of another embodiment, FIG. 4 is a block diagram of the configuration of a conventional example, and FIG. FIG. 10--Still video floppy 12--Spindle motor 14--Reproduction head 16--Reproduction amplifier 18--Brightness signal processing circuit 20--Color signal processing circuit 22, 44.46, 48.50 .52-A
GC circuit 24-N TSC encoder 26.
-Mixing circuit 28-・Low pass filter 30-・
-ID detection circuit 32-・System controller 34-
Synchronous signal removal circuit 36 --- Video level detection circuit 3
8-・Voltage control amplifier 40-・Selection switch

Claims (1)

[Claims] An image reproducing device for reproducing an image signal from an image recording medium, characterized in that the image reproducing device is provided with means for automatically adjusting the contrast of the reproduced image signal based on the average level of the video portion of the image signal. Device.