JPS5933076Y2 - light pen input device - Google Patents

Description

[Detailed description of the invention] This invention is based on the invention that some or all of the colors that make up the pictures, figures, or background patterns displayed on the image surface of a cathode ray tube (hereinafter referred to as CRT) have brightness such as black. When the screen is not used, the light pen input operation can be performed smoothly by converting only black to a bright color (for example, gray) and displaying it without affecting other bright colors. This invention relates to a light pen input device.

A light pen outputs a human pulse by receiving light generated from a Ti phosphor stimulated by an electron beam scanning the CRT surface, but for this reason, it is difficult to operate the light pen effectively even when the CRT is in the cut-off state. requires an operation to forcibly increase the brightness.

Given this, if the brightness of the entire screen is uniformly lowered to L regardless of the displayed color, the displayed color may change, and white and other colors may become saturated.

These also give unnecessary brightness to the eyes, making visual acuity undesirable.

The present invention aims to solve such problems, and will be described below with reference to the drawings.

FIG. 1 is a rotation configuration diagram showing an embodiment of the present invention.

In the same figure, each input terminal Ri, Gi, Bi is connected to R
(red), G (green), and B (blue) data are input.

Now, when a signal of level 1 is inputted from Ri, it is amplified by Bachauer B1 and sent to output terminal R via emitter follower Q1 with an amplitude determined by resistors R1 and R2.
output to o.

Output terminals Ro, Go, and Bo are BGB monitor 2
The data based on the output signals listed in L are displayed on the CRT screen.

Note that the other emitter follower Q2 is in a cutoff state at this time.

This operation is the same when signals are input to Gi and Bi.

Next, a case will be described in which the signals inputted from the input terminals Ri, Gi, and Bi are all low level, that is, black.

In this state, if the light pen switch 3, which is turned on when the light pen is pressed against the CRT screen, is in the on state,
Since the four inputs of NOR gate 4 are at low level Ic1, this output becomes high level, and the output of buffer B4 has a voltage amplitude determined by resistor RIO and variable resistor R11, which is applied to each emitter of Q2, Q4, and Qa. applied to the follower;

At this time Q1. Q2. Since the emitter follower of Q3 is in a cut-off state, the output terminal Ro.

A signal having a voltage amplitude based on the resistor Rto and the variable resistor R11 is output to Go and Bo, and the color of the data on the CRT screen becomes gray.

When light pen switch 3 is off, NOR gate 4
Since the output of is at a low level, all emitter followers from Ql to Qa are cut off, and the output data becomes black.

FIGS. 2A and 2B show time charts of signals from various parts when the light pen switch 3 is turned on.

Note that the NOR gate 4 constitutes a black detection circuit, and the buffer B, resistor R1o, semi-fixed resistor R11, emitter followers Q, , Qa, and resistors R3, R6, and Ro constitute a brightness conversion circuit.

The semi-fixed resistor R1□ is for adjusting the brightness level during brightness conversion.

As described above, the present invention increases the brightness of only black without affecting other colors when the light pen is pressed against the CRTh during light pen input. There is something very big.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of the main parts showing an embodiment of the present invention, Figure 2A
, B are time charts of signals of each part in FIG. Ri, Gi, B i --- Input terminal,
Ro, Go, Bo - Output terminal, Q1
~Q6-...Emitter follower R1J RIO
...Resistance, R11...Semi-fixed resistance, B
1-B4.../Matsufur 3...Light pen switch, 4...NOR gate.

Claims (1)

[Scope of utility model registration request] A light pen input device that inputs graphic data such as pictures and figures pixel by pixel using a light pen to the video screen of a color cathode ray tube that projects a multicolor image including at least black, When there is black in a picture, figure, background, etc. to be displayed, there is a black detection circuit that distinguishes it from other colors and detects it, and the output of the black detection circuit maintains the brightness of other colors and displays only black. 1. A light pen input device comprising: a brightness conversion circuit that converts a signal into a signal having brightness such as gray.