JPH0279897A - Remote display device - Google Patents

Abstract

PURPOSE:To hold stable display quality by receiving a parallel signal from a master device, converting the received parallel signal into a serial signal and displaying prescribed information corresponding to the serial signal. CONSTITUTION:When the output (parallel signal) 30 of a character generator 103 in a master display device 1 is outputted from an interface transmitting circuit 109, the frequency of a signal transmitted from the circuit 109 to an interface receiving circuit 201 can be reduced and the generation of waveform distortion can be suppressed. In a remote display device 2, the parallel signal 30 of the display data is received by the circuit 201, inputted to a P/S conversion circuit 203 and converted into a serial signal. Simultaneously with the input of the signal 30, a horizontally and vertically synchronizing signal 80 is inputted to an internal clock generating circuit 20, a displaying picture element clock signal 20 synchronized with the start of a laster is outputted and character information is displayed on a CRT 204. Consequently, stable display quality can be held.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a remote display device, and particularly to a CRT (cathode display device) installed in a remote location in an information processing device.
ray tube).

Traditionally, in this type of remote display device, the video signal, vertical synchronization signal, and horizontal synchronization signal transmitted from the main display device are received separately or as a combined composite signal, and the signals are sent through a display circuit. Afterwards, it was configured to be displayed on a CRT.

However, the above-mentioned conventional remote display devices are configured with analog circuits, and because the frequency of the video signal is high, the disadvantage is that as the distance from the main display device increases, the display quality deteriorates due to the influence of waveform distortion. there were.

An object of the present invention is to provide a remote display device that can maintain stable display quality even when the distance from the main display device increases.

11. A remote display device of the present invention is a remote display device that displays predetermined information in response to a signal from a higher-level device, and includes a receiving means for receiving a parallel signal from the higher-level device; The apparatus is characterized by comprising a converting means for converting a received parallel signal into a serial signal, and a display means for displaying predetermined information according to the serial signal converted by the converting means.

Kanse 3 Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of a remote display device according to the present invention, and shows a case where a signal transmitted from a main display device is received and information corresponding to the signal is displayed. .

In the figure, the main display device 1 includes a line counter 101,
It is configured to include a refresh buffer 102, a character generator 103, a parallel/serial conversion circuit 104, and a CRT 105.

The main display device 1 also includes a column counter 106, a raster counter 107, a timing control circuit 108, and an interface transmission circuit 109.

On the other hand, the remote display device 2 has an interface receiving circuit 201.
, internal clock generation circuit 202, and parallel-series circuit 203
and a CRT 204.

In this configuration, in the main display device 1, the contents of the refresh buffer 102 indicated by the row counter 101 and the column counter 106 are stored in the raster counter 107.
is added to the character generator 103 together with the value of , and a parallel signal display signal 30 is output. and,
When this display signal 30 is input to the parallel-serial conversion circuit 104, it becomes a raster brightness modulation signal which is a serial signal, and along with the horizontal and vertical synchronizing signals 80, 0 and above, which form characters on the CRT 105, operate in the same manner as before. be.

In this case, the output from the parallel-to-serial conversion circuit 104 is a pixel signal and has the highest frequency component. Therefore, if this pixel signal is outputted from the interface transmission circuit 109 as in the conventional method, the display quality will deteriorate due to waveform distortion.

Therefore, in the present invention, the character generator 10
3 (that is, a parallel signal) is output from the interface transmission circuit 109. By doing so, the frequency of the signal between the interface transmitting circuit 109 and the interface receiving circuit 201 can be lowered, making it difficult for waveform distortion to occur.

In the remote display device 1W2, the parallel signal of this display data is received by the interface receiving circuit 201 and inputted to the parallel-to-serial conversion circuit 203. At the same time, horizontal and vertical synchronization signals 80 are input to the internal clock generation circuit 202.
, pixel clock signal 2 for display synchronized with the start of the raster.
0 is output and CR is generated by the same operation as in the main display device 1.
Text information will be displayed on T 204.

Next, the conversion process of the display data signal within the remote display device 2 will be explained using FIG.

The figure shows a case where one character on a CRT has eight pixels per rask.

First, the output 30 from the character generator 103 of the display device 1 is input to the parallel-to-serial conversion circuit 203 of the remote display device 2 via the interface transmitting circuit 109 and the interface receiving circuit 201. At the same time, the horizontal synchronization signal output from the timing control circuit 108 of the main display device 1 is sent to the internal clock generation circuit 202 via the interface transmission circuit 109 and the interface reception circuit 201.
A pixel clock signal synchronized with the horizontal synchronization signal is sent out.

This pixel clock signal is input to the parallel-to-serial conversion circuit 203, and the output 30 is subjected to parallel-to-serial conversion. If the output 30 is r 001110GG as shown in the figure, the parallel-to-serial conversion circuit 203 outputs a video signal as shown in the figure,
Character information is displayed on the CRT 204.

In this case, the frequency of the signals on the interface transmitting circuit 109 and the interface receiving circuit 201 can be reduced to 1/8 of the conventional frequency, making it difficult for waveform distortion to occur.

In other words, since the present invention transmits and receives parallel signals instead of conventionally transmitting and receiving serial signals, there is no high frequency signal and waveform distortion is less likely to occur.

1. As explained above, the present invention has the advantage that by lowering the frequency of signals to be transmitted and received, stable display quality can be maintained even if the distance between the main display device and the remote display device becomes long. There is.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a remote display device according to an embodiment of the present invention, and FIG. 2 is a time chart showing an example of a conversion processing operation in the remote display device of FIG. Explanation of symbols of main parts 103...Character generator 104,
203...Parallel-serial conversion circuit 105, 204...
・・・・・・CRT

Claims (1)

[Claims] (1) A remote display device that displays predetermined information according to a signal from a higher-level device, comprising a receiving means for receiving a parallel signal from the higher-level device, and converting the parallel signal received by the receiving means into a serial signal. a conversion means for converting;
A remote display device comprising display means for displaying predetermined information according to the serial signal converted by the conversion means.