JPS63232682A - Video signal transmitting/receiving system - Google Patents

Abstract

PURPOSE:To obtain the best signal transmitting path without spoiling the compatibility with conventional video signal transmitting systems, by installing a gamma-correction processing circuit and a means which discriminates signals for controlling the circuit to a receiver and a means which adds discriminating signals indicating gamma-corrected states to input signals to a picture signal transmitter. CONSTITUTION:When video signals without gamma-correction are inputted to a receiver 11 from a TV camera 10, a gamma-correction discriminator 6 discriminates the 'without gamma-correction' and switches a change-over switch 9 to a contact 9b side so as to send signals which do not pass a reverse gamma-correction circuit 7 to a liquid crystal LCD 8. When a TV camera system 10a of a conventional type is connected to the receiver 11, gamma=0.45 and the discriminator 6 discriminates the 'gamma-correction' and switches the switch 9 to another contact 9a side so as to send signals passed through the circuit 7 to the LCD 8. When signals 'without gamma-correction' are inputted to a receiver 15 using a CRT 14, the switch 9 is switched to the contact 9b side by the discriminator 6 and correction of gamma=0.45 is performed. In the case of signals 'with gamma-correction', the switch 9 is switched to the contact 9a side and the signals are inputted to the CRT 14 without gamma-correction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a video signal transmitting/receiving system, and particularly to a television (hereinafter referred to as "TV") signal transmitter/TV signal receiver.

[Prior Art] The image display means in conventional TV signal receivers in this village were generally cathode ray tubes (hereinafter referred to as CRTs), so the difference between the input signal voltage E of the CRT and the light emitting output of the picture tube was The gamma value γ that represents kf is γ = 2.2, and mainly for economic reasons, γ = 0 is set so that the system γ value is 1 (linear characteristic) at the TV camera on the sending side. .45 correction processing was performed and the video signal was sent out.

However, in liquid crystal image display devices (hereinafter referred to as LCD) that have appeared on the market in recent years,
The γ value of the LCD itself is 1, but in order to inversely correct the γ=0.45 correction on the sending TV camera side, a γ=2.2 correction is performed at the signal processing stage.

[Problem that the invention seeks to solve]

However, as mentioned above, even though the γ value is 1 for both the transmitting-side imaging unit and the receiving-side display unit, performing γ correction and inverse γ correction on both sides is only non-responsive. First, it has the disadvantage of causing deterioration in the gradation expressiveness of reproduced images.

The present invention has been made in view of the problems of the prior art as described above, and eliminates the cause of the deterioration of the expressive power of Ia by avoiding passing through an originally unnecessary signal processing process without losing compatibility with the conventional system. The first objective is to provide an image output/output system that can eliminate .

(Means for Solving the Interval Point Problem) Therefore, in the present invention, γ
A receiver comprising a circuit for performing correction processing, a display means for reproducing the corrected signal, a means for determining No. 42 for controlling the γ correction processing circuit, and a determination representing the γ correction state. The above object is achieved by combining the image transmitter No. 8 with a means for adding a signal to the tuna input signal.

[Effect]

With the above configuration, when using an image display device with γ=1, such as an LCD, for example, γ correction is not performed on the video signal sending side, and a discrimination signal without γ correction is added to the TV signal and sent out. However, on the image receiving side, using the discrimination signal without γ correction, it becomes possible to manually input the video signal to the display device without performing inverse γ correction, and 9, it maintains universal compatibility with conventional systems. obtain.

(Example) The present invention will be explained below based on examples.

FIG. 1 is a block diagram of an embodiment of a video transmission/reception system according to the present invention.

(Configuration) In Fig. 1, IO is a TV camera, which is a video signal transmitter! 1 is a video monitor which is a receiver. 1 is a photographing lens for forming an image of the subject, 2 is an image pickup element with γ=1, and 3 is a control amplifier, and this amplifier 3 includes a γ correction circuit. No correction” (
γ=1). 4 is an encoder, 5 is a discrimination signal for "no γ correction", and a Δ signal generator.
It is arranged in a place that can be freely used for each TV system such as NTSC or PAL, for example, in vertical blanking. As a result, a "no correction" determination signal is output to the TV signal without γ correction.

On the other hand, in the video monitor 11 on the receiver side, 6 is a γ correction discriminator, 7 is an inverse γ correction circuit, 9 is a video signal changeover switch, 9a and 9b are switching contacts, and 8 is a γ=1 video display device. The LCD shown in FIG.

(Operation) In the system structure described above, when the image (8"+) from the TV left camera 0 is input to the receiver 11, the γ correction discriminator 6 determines that there is no γ correction, and the switch is switched. The switch 9 is switched to the contact 9b side, and the signal that does not pass through the inverse γ correction circuit 7 is sent to the LCD 8.

Next, Figure 2 shows a conventional type T as a video signal transmitter.
2 is a diagram illustrating an example in which the V camera system loa can be reversibly connected to/used in the receiver 11 in FIG. 1. FIG. In the figure, 1 and 2°4 indicate the same (equivalent) components as in FIG. 1, respectively. 12 is a single control amplifier, and γ=0.45. When inputting this output to the receiver 11, the γ correction discriminator 6 determines that γ correction is present, and switches the contact of the changeover switch 9 to the 9a side. It operates so that the number is manually input to the LCD 8.

The following operational sequence flowchart is shown in FIG. Since the diagram is self-explanatory, a detailed explanation of each step will be omitted.

FIG. 4 also shows that in the system of the present invention, the CRT 14
Receiver when using! FIG. 5 is a configuration block diagram of No. 5. In the figure, 6.9 indicates the same (equivalent) component as in the receiver 11 of FIG. 1, respectively. 13 is a γ correction circuit with γ=0.45. When the signal "No γ correction" is input manually, the γ supplementary IF discriminator 6 switches the changeover switch 9 to the contact 9b side, performs a correction of γ = 0.45, and inputs it to the CRT 14. . In addition, in the case of manual input with "γ correction IE" (in the case of No. a, the changeover switch 9 is switched to the contact 9a side by the γ correction discriminator 6, and the operation is performed so that the CRT 14 is manually operated without performing γ correction. do.

FIG. 5 is a flowchart of the above operation sequence, and for the same reason as in FIG. 3, a sequential explanation of each step will be omitted.

(Effects of the Invention) As described above, according to the present invention, since the γ correction determination signal is added to the input video signal, the best possible output can be achieved without losing compatibility with the conventional video signal transmission system. We were able to construct this type of system that provides a signal transmission path for

[Brief explanation of drawings]

FIG. 1 is a block diagram of the configuration of an embodiment of the system according to the present invention, FIG. 2 is a side view of conversion to a conventional TV camera system, and FIG. 3 is a flowchart of the operation sequence in FIGS. Figure 4 shows the CR in the system of the present invention.
FIG. 5, which is a block diagram of an example of the configuration of the T receiver side, is a flowchart of its operation sequence. 3... Control amplifier 5 --- No γ correction discrimination No. 43 full generator ---
-1 gamma correction discriminator 7----inverse gamma correction circuit 8...-LCD 9...changeover switch 10, 10a==video signal transmitter 11, 15---- Pass receiver 14---CRT

Claims (1)

[Claims] A receiver comprising a circuit that performs γ correction processing on an input video signal, a display unit that reproduces the corrected signal, and a unit that determines a signal that controls the γ correction processing circuit, and the γ correction process. A video signal transmitting/receiving system comprising: a video signal transmitter including means for adding a discrimination signal representing a state to the input video signal.