JPS644137Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a signal transmission circuit that connects a personal computer or the like to a color television receiver or color monitor receiver with an RGB terminal.

(b) Conventional example 2 shows a schematic diagram of the conventional signal transmission circuit of FIG. 1; FIG.

In Figure 1, 1 is the video input terminal a and
Color monitor receiver equipped with RGB input terminal b,
Note that RGB input generally uses RGB three primary color signals R, G,
B, a synchronization signal (SYNC) consisting of a horizontal synchronization signal H and a vertical synchronization signal V, and ground G. 2 is
An RGB primary color signal source in the personal computer 3 is connected to the RGB input terminal b, and 4 is a video signal source connected to the video input terminal a, for example, a color television tuner or a video tape recorder. 6 is a first path for transmitting the signal from the video signal source 4; 7 is a video signal processing circuit that processes the video signal and converts it into an RGB signal; 8 is an RGB processing circuit; 9 is an RGB primary color signal from the RGB signal source 2. 10 is an interlocking switch S ₁ ,
This is a changeover switch circuit consisting of S ₂ , S ₃ , and S ₄ that switches between the output of the video signal processing circuit 7 and the second path 9 and selectively transmits the output to the drive circuit 11 and picture tube 12 at the subsequent stage. Note that FIG. 1 is an example of a combination of a color monitor receiver and a device that supplies signals to it; however, in the case of a color television receiver, the video signal source 4 and the color monitor receiver 1 shown in FIG. You can think of the parts as a whole.

In the signal transmission circuit shown in FIG. 1, when the switches S ₁ to _{S 4} of the changeover switch circuit 10 are connected to the second path 9 side, the color monitor receiver 1 is used as a color display device for the personal computer 3. When creating or checking a program, the program displayed on the picture tube 12 is generally a black and white image. However, it has the disadvantage that color shift occurs in the white portion of a monochrome image due to a shift in convergence of the picture tube 12, making the image difficult to see. For this purpose, it is possible to operate the personal computer 3 to change the color of the image such as a program displayed on the picture tube 12 to one of R, G, and B, but in order to realize this, it is necessary to You must perform an operation to make the image a single color, and then perform an operation to display a new image of the program, etc. Therefore, it is not possible to change the currently displayed black and white image to a single color (for example, green) image.

(c) Purpose of the invention This invention was made in view of the above points, and when an image representing a personal computer program etc. is displayed on the picture tube as a black and white image, it is possible to change the raster of the picture tube to one color. The present invention provides a signal transmission circuit that eliminates color shift in images.

(d) Structure of the invention The invention is characterized in that the second path is provided with a second changeover switch circuit that cuts off two of the RGB primary color signals and transmits only the remaining one primary color signal. This is a signal transmission circuit.

(E) Embodiment FIG. 2 shows a schematic diagram of an embodiment of the signal transmission circuit of the present invention. Incidentally, the same parts as in FIG. 1 are given the same reference numerals and redundant explanation will be omitted. In Figure 2,
Reference numeral 13 denotes a second changeover switch circuit that connects the R primary color signal line and B primary color signal line of the second path 9 to resistors R ₁ and R ₂ whose one end is grounded by switches S ₅ and S ₆ that operate in conjunction with each other. be.

In the signal transmission circuit shown in FIG. 2, when the switches S ₁ to _{S 4} of the changeover switch circuit 10 are connected to the second path 9 side and a black and white image representing a personal computer program etc. is displayed on the picture tube 6, the color By switching the switches S ₅ and S ₆ provided on the front of the monitor receiver, etc., the R primary color signal line and the B primary color signal line of the second path 9 are connected to the resistors R ₁ and R _{2 .}
Ground through. Therefore, substantially only the G primary color signal is transmitted to the subsequent drive circuit 11, etc., and the raster of the picture tube 12 becomes only G (green), eliminating color shift and reducing eye strain on the user.
Further, when the switches S ₁ to _{S 4} are switched to the first path 6 side, the image is not affected by the switches S ₅ and S ₆ . Moreover, the second changeover switch circuit 1
3 may be provided not only in the color monitor receiver 1 but also in the personal computer 3 and the cable between the personal computer 3 and the color monitor receiver 1. In addition, as a method of blocking the R primary color signal and the B primary color signal, as in this embodiment, the resistors R ₁ ,
It is also possible to simply disconnect the R primary color signal line and the B primary color signal line of the second path 9 using a switch, without using _R2 .

(f) Effects of the invention As described above, according to the invention, the black and white image displayed on the picture tube, which represents a personal computer program, etc. is changed to a single color by the second changeover switch circuit, making it an image with no color shift, so that it is easier for the user to use the invention. It can reduce eye fatigue. Further, since the second changeover switch circuit has a simple structure, the present invention can be implemented at low cost and is useful.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a conventional signal transmission circuit, and FIG. 2 is a schematic diagram of an embodiment of the signal transmission circuit of the present invention. 2...RGB primary color signal source, 4...video signal source,
6...First path, 7...Video signal processing circuit, 9
...Second path, 10...Changing switch circuit,
11...drive circuit, 12...picture tube, 13...
...Second changeover switch circuit.

Claims (1)

[Scope of utility model registration request] a first path for transmitting signals from a video signal source; a signal processing circuit for processing signals in the first path and outputting RGB signals; and a second path for transmitting RGB primary color signals from an RGB primary color signal source; A signal transmission circuit including a changeover switch circuit that switches between the output of the signal processing circuit and the RGB primary color signals of the second path and selectively transmits them to the picture tube, wherein two of the RGB primary color signals are connected to the second path. 1. A signal transmission circuit comprising a second changeover switch circuit that cuts off two primary color signals and transmits only the remaining one primary color signal.