JPS60108931A - Information processing system - Google Patents

Abstract

PURPOSE:To use a signal cable reducing the number of signal lines by using a signal line transmitting a display signal from a processor to a CRT display device also for the transmission of data from a keyboard to the processor. CONSTITUTION:A CRT display device 14 is switched by transmission/reception switching circuits 2, 40 so as to send input information from a keyboard 12 to a processor 10 through a transmission line during the blanking period of a display synchronizing signal, and receive a display signal from the processor 10 in the other period. The processor 10 is switched by transmission/reception switching circuits 1, 18 so as to receive input information from the keyboard 12 from the device 14 through the transmission line during the blanking period of the display synchronizing signal, and send a display signal to the device 14 in the other period. Said constitution makes it possible to reduce the number of signal lines, so that a single cable reducing the number of signal lines can be used.

Description

TECHNICAL FIELD The present invention relates to an information processing system, and more specifically to an information processing system equipped with an input/output device consisting of a keyboard and a CRT display device.

BACKGROUND OF THE INVENTION In an information processing system such as a novel computer having an input/output device consisting of a CRT display device with a keyboard, a CRT control section for creating a video signal and a synchronization signal based on predetermined data is housed in a processing device body. In this case, the display signal transmission cable that connects the processing device main body and the CRT display device usually has only a video signal line and a synchronization signal line, so it is not possible to send the data input by key date to the processing device main body. A separate cable for keyboard data transmission is required. Therefore,
Conventionally, two sets of connection lines were provided to connect the input/output device and the main body of the processing device. For this reason, when a multi-core cable or two cables are used, the connection wire is thick and heavy, the assembly work of the device is troublesome, the handling is inconvenient, and the cost is high.

Purpose The present invention aims to solve the drawbacks of the prior art and provide an information processing system that does not require a large number of signal lines to connect input/output devices and a processing device main body. The configuration of the invention will be described below based on one embodiment.

FIG. 1 is an external perspective view showing an information processing system according to the present invention, in which a processing device main body 10 and a CRT display device 14 equipped with a keyboard 12 are connected by a connecting cable 1.
Connected by 6 and teed. In the embodiment of FIG. 1, the space between the keyboard 12 and the CRT display device 14 is constructed separately and has elasticity so that the keyboard 12 can be moved to an appropriate position as desired. Although they are connected by a coil cable 18, they may be integrated. The processing device main unit 0 has a function of performing a predetermined processing operation based on data input through the keyboard 12 and creating an output signal for outputting the processing result. This output signal is sent to the CRT display device 14 via the connection cable 16 and displayed as an image on the screen 14A.

On the other hand, the keyboard 12 has a key 2 that is accessible to the operator.
It has a function of generating code data corresponding to the definition of the key 20 when 0 is pressed, and this code data is sent to the CR via the data sending line 18A of the coil cable 18.
The signal is sent to the T display device 14 and is input to the processing device main body 10 by sharing the connection cable 16 for transmitting the display signal.

FIG. 2 shows a block configuration of the processing device main body 10, the CRT display device 14, and the keyboard 12. The processing device main body 10 includes a processing section (not shown) including a CPU and the like, as well as a video signal generation circuit 22 that forms part of a CRT control section that creates display signals based on processed data.
and a synchronization signal generation circuit 24. The video signal generation circuit 22 serially outputs predetermined dot data corresponding to a character pattern, etc. of the negative character, one raster at a time, as a raster scanning video signal (see FIG. 3), and the synchronization signal generation circuit 24 outputs horizontal and vertical synchronizing signals (see FIG. 3) for synchronizing on the CRT display device 14 side. These video signals and horizontal/vertical synchronizing signals are transmitted to the CRT display device 1 via signal lines 16-A to 16C provided in the connection cable 16.
Sent on 4th.

The CRT display device 14 includes a luminance signal generation circuit 26 that inputs a video signal and modulates the luminance of dot data, and an input circuit that inputs horizontal and vertical synchronizing signals and generates an X, Y curve tower d1 signal. The camera is equipped with a brightness signal and a sweep signal, and by applying these brightness signals and sweep signals to the cathode ray tube 30, predetermined character information and the like are displayed on the screen 14A.

The keyboard 12 includes a key matrix 3-2 that generates key signals in the X and Y directions when a key 20 is pressed, an encoder 34 that converts the key signals into predetermined code data, and parallel codes converted by the encoder 34. The parallel-to-serial converter 36 converts data into serial data and temporarily stores the data, and the parallel-to-serial converter 36 outputs data 18.
A is energized by a transmission ready signal 18B input from the outside and is sent to the CRT display device 14 side via the coil cable 18.

The CRT display device 14 to which code data is input from the keyboard 12 and the processing device main body 10 are each provided with switching control circuits 38 and 40 for switching the transmission/reception direction of the video signal/key date data line 16A. The code data sent from the keyboard 12 during the signal blanking period is transferred to the video signal/keyboard data line 16.
The data is sent to the processing device main body 10 side via A. That is, the video signal/keyboard data line 16A in the processing device main body 1O is provided with buffer amplifiers 42 and 44 in opposite directions in parallel for switching the transmission direction, and the input side of the buffer amplifier 42 in the output direction The output side of the video signal generation circuit 22 is connected to.

A serial-to-parallel converter 46 is connected to the output side of the buffer amplifier 44 in the input direction. The switching control circuit 40 is energized by the horizontal synchronization signal output from the synchronization signal generation circuit 24, and drops the drive voltage of the buffer amplifier 42 to zero at the rising timing of the horizontal synchronization signal, and controls the buffer amplifier 742 portion. At the same time, a predetermined drive voltage is applied to the buffer amplifier 44 to connect the video signal/keyboard data line 16A to the serial-to-parallel converter 46. Conversely, at the falling timing of the horizontal synchronization signal, the buffer amplifier 42 is turned on and the buffer amplifier 44 is opened.

Similarly, on the CRT display device 14 side, buffer amplifiers 48 and 50 for switching the transmission direction to the video signal/keyboard data line 16A are provided in parallel in opposite directions. The luminance signal generation circuit 26 is connected to the output side of the output direction amplifier 48, and the output side of the parallel-to-serial converter 36 of the keyboard 12 is connected to the input side of the input direction amplifier 5o. Then, the switching control circuit 38 opens the amplifier 48 and the amplifier 5o at the rising timing of the horizontal synchronization signal, and simultaneously converts the transmission ready signal from parallel to serial via the command signal line 18B provided in the coil cable 18. Exit to t'j 36. If code data has been accumulated at the time of receiving the transmission ready signal, this parallel-to-serial converter 36 serially sends the code data bit by bit to the CRT display device 14 via the data sending line 18A. (Refer to the keyboard large sword data in Figure 3). This code data is the video signal line 16
A, the data is input to the processing device main body 10 side, converted into the original parallel code data by the serial-parallel converter 46, and sent to the processing section. When the transmission ready signal is received, the
When there is no data in serializer 36, no data transmission occurs during the horizontal blanking period.

Subsequently, at the falling edge timing of the horizontal synchronization signal, the switching control circuit 38 passes through the buffer amplifier 48 and opens the buffer amplifier 50.

During the horizontal blanking period when the horizontal synchronization signal is at the "high" level, the video signal is at the "low" level as shown in FIG. It becomes possible to transmit the code data to the processing device main body lo side. At this time, due to the switching operation of the transmission/reception direction synchronized with the horizontal synchronizing signal by the switching control circuits 38 and 40, the video signal and code data are not driven simultaneously on the video signal line, and the horizontal blanking period ends. For example, since the video signal is again sent from the processing device body 10 to the CRT display device 14, the quality of the video displayed on the screen 14A does not deteriorate.

Note that the code data may be transmitted using the vertical blanking period.

Effects According to the present invention, the signal line for sending display signals from the processing device to the CRT display device can also be used in common when sending data from the keyboard to the processing device, so the number of signal lines can be reduced. A single group with fewer signal lines can be used.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing an information processing system according to an embodiment of the present invention, FIG. 2 is a block diagram showing the electrical configuration of each part of the information processing system shown in FIG. 1, and FIG. 3 is a timing chart showing each signal transmitted through the connection cable in the figure. Explanation of symbols of main parts 10...Processing device body 12...Key bead 14...CRT display device 16...Connection cable 16A...Video signal/key? - data line 22...
・Video signal generation circuit 24...Synchronization signal generation circuit 38.40...Switching control circuit Patent applicant Ricoh Co., Ltd.

Claims (1)

[Scope of Claims] A processing device including a display control means for outputting a display signal consisting of a Rusk scan video signal and a display synchronization signal, and displaying an image on a screen based on a display signal sent from the processing device through a transmission line. and a keyboard connected to the display means for inputting information, wherein the display means transmits information input from the keyboard to the transmission path during a blanking period of the display synchronization signal. a first transmitting/receiving switching means for switching the transmission path so as to transmit the display signal to the processing device through the processing device and receive the display signal from the processing device during other periods; A second method for switching the transmission path so that input from the keyboard and pictures are received from the display means through the transmission path during the blanking period, and display signals are sent to the display means during other periods.
An information processing system 0 characterized in that it has a transmission/reception switching means.