JPH06233313A - Video signal processing circuit - Google Patents

Abstract

PURPOSE:To decrease the number of pins by dealing with both outputs of normal and high picture quality types by means of a single output terminal. CONSTITUTION:Plural Y/C mixing circuits are contained in a video signal processing circuit as the external circuits 3 or the built-in circuits 1 and 2. Therefore both outputs of normal and high picture quality types can be transmitted through a single output terminal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing circuit, and more particularly to a video signal processing circuit having a Y / C mix circuit.

[0002]

2. Description of the Related Art In the conventional video signal processing circuit of this type, a video signal processing IC or other video processing circuit has a Y / C mix circuit.

In order to obtain high-quality output and normal output with this conventional configuration, it is necessary to add an independent output terminal. That is, in order to produce a high quality type image with a normal type configuration and output it, an independent output terminal for the Y signal had to be added. Also, if you try to make a normal type with a high image quality type configuration, Y / C
I had to add a mix output. This will be described with reference to FIG. 3 showing a conventional technique. As shown in FIG. 3, a Y output terminal 4a and a Y / C output terminal 4b are
It is necessary to provide each independently. Therefore, the number of pins has increased, and this has been a bottleneck for making the input / output circuit a simple system configuration. In the figure, reference numeral 4c indicates Y /
The C input terminal is shown, and the video output terminal is shown by 4d.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems of the prior art and to provide a video signal processing circuit capable of reducing the number of pins and thus making the input / output circuit simple. And

[0005]

According to the invention of claim 1 of the present application, in a video signal processing circuit having a Y / C mix circuit, by providing a plurality of Y / C mix circuits, a high image quality output and a normal output can be obtained. A video signal processing circuit characterized in that and can be output by one output terminal, and thereby achieves the above object.

According to the invention of claim 2 of the present application, one of the Y / C mix circuits is provided in the video signal processing internal circuit, and the Y / C mix circuit is provided.
The video signal processing circuit according to claim 1, wherein the other one of the mix circuits is configured as an external circuit, and thereby the above object is achieved.

The invention according to claim 3 of the present application is characterized in that a Y / C mix circuit is provided in a circuit for processing a plurality of video signals, and the Y / C mix circuit is switched by a control signal. The video signal processing circuit according to item 1. Therefore, the above object is achieved thereby.

[0008]

According to the invention of the present application, by providing a plurality of Y / C mix circuits, for example, one of the Y / C mix circuits is provided in the video signal processing built-in circuit and the other of the Y / C mix circuits is provided. By configuring one as an external circuit, or by providing a Y / C mix circuit in a circuit for processing a plurality of video signals and switching the Y / C mix circuit by a control signal, high image quality can be achieved. Since the output and the normal output can be output from one output terminal, the number of pins can be reduced and the input / output circuit can be made simple.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Of course, the present invention is not limited to the embodiments.

Embodiment 1 In this embodiment, as shown in FIG. 1, one of the Y / C mix circuits is provided in a video signal processing internal circuit, and the other one of the Y / C mix circuits is an external circuit. Configured as 3. As a result, the terminals are the Y output terminal 41 and the Y input terminal 42.
Therefore, it is possible to use three terminals, that is, the video output terminal 43, and both the high-quality output and the normal output can be output without increasing the number of conventional terminals.

For example, in the present embodiment, in the case of 8 mm video signal processing, a high image quality output type video device called "high eight" developed by the applicant of the present invention can be switched to enable normal output. It can be embodied as a configuration. That is, in FIG. 1, if the external Y / C mix circuit which is the external circuit 3 is not provided, this may be used only in the high image quality type high-eight system, but cannot be applied to the normal type. Therefore, by configuring one of the Y / C mix circuits as the external circuit 3 as in the present embodiment, it is possible to support the normal type. In FIG. 1, reference numeral 6 is a delay line, and when the delay line is operating, C-MUTE
When turned on, C cut is made.

According to the present embodiment, in the video signal processing circuit configuration, the conventional Y / C mix circuit is provided in one place and in one place.
By providing this Y / C mix circuit in multiple places, it becomes possible to output both high-quality output and normal output (composite output), while increasing the number of pins. It is possible to achieve without the need for IC, thus reducing the number of IC pins and reducing power consumption (1
It was possible to achieve 5% with a pin) and a simple structure.

Embodiment 2 In this embodiment, as shown in FIG. 2, a Y / C mix circuit is provided in a circuit incorporating a plurality of video signals (reference numeral 1 in FIG. 2).
Indicates the first circuit and reference numeral 2 indicates the second circuit), and the Y / C mix circuit is switched by a control signal. With this configuration, the terminals 51,
With 52, high-quality output and normal output can be obtained without increasing the number of terminals.

This embodiment is advantageously employed when it is desired to avoid adding the external circuit 3 as in the example shown in FIG. The configuration of this embodiment will be described in more detail as follows. Please refer to FIG.

In the present embodiment, the Y / C mix circuit is provided both before and after the output terminal of the IC as the first circuit 1 and the second circuit 2.

The first circuit 1 and the second circuit 2 which are the Y / C mix circuits are configured so that only one of them is selected depending on the Y / C mix position switching mode.

The Y / C mix position changeover switch is
As shown in FIG. 2, it is included in a C-MUTE (chroma mute) circuit. This switching is performed by connecting to either (1) or (2) of FIG.

If Y / C mixing is not performed, Y / C
This is done by muting the C signal entering the mix circuit in front of the Y / C mix position selector switch.

By using the video signal processing circuit of this embodiment, the following application can be applied to a normal type video device and a high image quality type video device.

(For a normal type video device)
Normally, a normal type video device has a high quality terminal (S
Terminal). Therefore, the first circuit 1 shown in FIG.
Y / C mix is performed with / CMIX (1), and Pin (a) output from the terminal 51 is output in the Y / C mix state. Further, when delay is applied for correction of skew distortion, it is more convenient to output in the Y / C mixed state because the delay line only needs one place and the cost is reduced.

(Compared to a high image quality type video device) Normally, a high image quality type video device has a high image quality terminal (S terminal). Therefore, the second circuit 2 shown in FIG.
/ CMIX (2) is used to perform Y / C mixing, whereby the Pin (a) output from the terminal 51 becomes an output of only the Y signal, which can be used as it is for high image quality output. When delay is applied to correct skew distortion, etc.
This is more convenient because the image quality is better when the signal and the C signal are independently performed.

According to the present embodiment, in the video signal processing circuit configuration, the conventional Y / C mix circuit is provided in one place and in one place.
The Y / C mix circuit, which has a circuit configuration, is provided in a plurality of places so that the signal processing of the normal type video and the high image quality type video can be switched. High-quality output and normal output (composite output) can now be shared with the output terminal. The number of IC pins can be reduced, and power consumption can be reduced (about 5% per pin). Furthermore, it can have a simple configuration, in particular,
It has become possible to support high image quality output with the simple configuration of the input / output circuit. Moreover, the same IC can be used by switching between a normal type video and a high quality type video with high quality output.

[0023]

According to the video signal processing circuit of the present invention,
Both normal type and high image quality output can be supported without increasing the number of pins, and thus the number of pins can be reduced. In addition, the input / output circuit can have a simple structure.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating a video signal processing circuit according to a first embodiment.

FIG. 2 is a configuration diagram illustrating a video signal processing circuit according to a second embodiment.

FIG. 3 is a configuration diagram showing a conventional video signal processing circuit.

[Explanation of symbols]

1 1st circuit (1st Y / C mix circuit) 2 2nd circuit (2nd Y / C mix circuit) 3 External circuit (external Y / C mix circuit)

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hideki Hirose 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (3)

[Claims] 1. A video signal processing circuit having a Y / C mix circuit, wherein a plurality of Y / C mix circuits are provided so that a high image quality output and a normal output can be output by one output terminal. Characteristic video signal processing circuit. 2. A video signal processing built-in circuit has one of the Y / C mix circuits, and the other one of the Y / C mix circuits is configured as an external circuit. The described video signal processing circuit. 3. The video signal processing according to claim 1, wherein the Y / C mix circuit is provided in a plurality of video signal processing built-in circuits, and the Y / C mix circuit is switched by a control signal. circuit.