JPS6352387B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a display device that electronically displays characters and the like.

Conventionally, electronic display devices such as CRTs (cathode ray tubes) have often been used as display devices for use with computers; however, unless special consideration is given to the internal circuitry of the computer, this type of device cannot display characters easily. The brightness of the points that make up the area are all the same.

However, in the conventional method, if the brightness of the image is uniformly high, it will cause eye strain for the monitor, so although visibility will decrease somewhat, it is important to emphasize that the screen brightness is low enough to be comfortable. was adjusting.

From this viewpoint, an object of the present invention is to provide a display device that reduces eye fatigue of a monitor by increasing the screen brightness at necessary locations compared to other locations.

According to the present invention, in an electronic display device for characters, etc., a means for detecting the display location of a specific symbol from an input signal and adjusting the brightness of the display around the location of the display device where the symbol is displayed. is given. A matched filter or an acoustic surface wave filter can be used as a matching detection circuit for a specific signal corresponding to a predetermined symbol from an image input signal to the display device, and identifies the location where the predetermined symbol is generated. In order to identify the display location, a character display whose brightness exceeds a certain level is first detected by horizontal scanning of the screen, and this output is continuously generated at a predetermined number of times at regular intervals in response to the vertical scanning of the screen. can be detected. It has a register that stores the position of the line containing a specific character,
The brightness of the screen may be adjusted according to the contents of this register. It is also possible to update the contents of the register by repeatedly detecting a specific character at regular intervals.

FIG. 1 is a conceptual diagram of a brightness enhancement device of the present invention shown in relation to a CRT display device. In the figure, 1 is an input terminal, 2 is a receiving circuit, 3 is a CRT like a cathode ray tube, 4 is an amplitude modulation circuit, and 5 is a specific symbol detection circuit. The amplitude modulation circuit 4 and the specific symbol detection circuit 5 are added according to the present invention, and details of an embodiment that targets a cursor symbol, that is, a set of luminances forming a rectangle as a special symbol, are shown in FIG. 2 and FIG. This will be explained using Figure 3.

The basic operation of the present invention is that when a certain symbol or figure is displayed on a display device, a modulation signal is generated that visually emphasizes the brightness of the row in which this symbol is displayed or several rows above the row. This generates amplitude modulation to the output signal from the receiving circuit 2 and displays it on the cathode ray tube 3.The details will be described below with reference to FIGS. 2 and 3.

In FIG. 3, 6 constitutes an amplitude modulation circuit corresponding to 4 in FIG. 1, 7 to 14 constitute a specific signal detection circuit 5 corresponding to 5 in FIG. 1, and 7 constitutes a high brightness section length detection circuit. 8 is a threshold circuit, 9 is a specific pattern detection circuit, 10 is a row number counter, 11 is a register write circuit, 12 is a register read circuit, 13 is a register, and 14 is a register control circuit.

The video signal 15 at the terminal 33 outputted from the receiving device 2 in FIG. circuit 7
It is outputted by the integrating circuit etc. that constitute the. This output signal is shown at 16 in FIG. This output 16 is given to the threshold circuit 8, which generates an output as shown at 17 or 18 if high luminance persists for a certain period of time or more. 18 is a scaled-down representation of the time axis of 17. The pulse generation pattern discrimination circuit 9 receives these outputs 17 and 18, and detects a pulse group 27 (FIG. 3, 18) that has occurred more than a predetermined number of times at a predetermined interval using a matched filter or the like, and outputs a pulse indicating the presence of a specific signal. Generates 20. Figure 3 1
9 is an example of a signal inside the circuit 9, and 26 is a detection threshold value. When this pulse output 20 occurs during a register write period set at regular intervals by the row number counter 10 which receives a synchronization signal from the receiving circuit 2 applied to the terminal 34, the screen being scanned at that time Register 1 corresponding to the line number of
The bit in 3 is set by the register write circuit 11 as shown at 21, and if this pulse output 20 is not generated, that bit is reset and the display brightness distribution of the screen is stored in the register 13. Writing to the register 13 is not performed except during the register writing period. Each bit of the contents of the register 13 is sequentially read out once for each vertical scan in correspondence with the vertical scan 24 of the screen, and is sent to the amplitude modulation circuit 6 as a rectangular wave modulation signal 22 to assemble the necessary video signal 23. The signal in section 29 is emphasized with respect to section 28 and output. The register control circuit 14 synchronously controls the operations of the register write circuit 11 and the read circuit 12.

FIG. 4 shows another embodiment in which the three circuits 7, 8, and 9 shown in FIG. 2 are replaced with 30, 31, and 32, respectively. In FIG. 4, delay circuits T-1 to T
-m30 each have a separate delay time, and the difference between these delay times is adjusted to approximately an integral multiple of the time required for one horizontal scan of the display screen. The output signals of the delay circuits 30 are each passed through a matched filter F.
-1 to F-m31, and when a voltage change matching the voltage change pattern set by each filter is detected, a pulse is output. These pulses are collected in an AND circuit 32, and when pulses are output from all matched filters 31 at the same time, a pulse is output. In this embodiment, if the voltage change patterns set in the matched filter 31 are all rectangular waves corresponding to the width of the cursor symbol, it is natural that the same function as the example of FIG. 2 can be provided. By setting a pattern corresponding to an arbitrary character or symbol in the matched filter 31 used in the illustrated embodiment, the presence of an arbitrary character or symbol can be detected.

Since the device according to the present invention specifies the brightness adjustment location using a displayed symbol, it does not require any mechanical modifications to the computer that is the input signal source, so it can function as is on many computers that are already in use. This is extremely beneficial as it can reduce visual fatigue for many workers.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing the principle of the present invention, Fig. 2 is a circuit diagram of an embodiment of the invention, Fig. 3 is an operation waveform diagram of Fig. 2, and Fig. 4 is a partial variation of Fig. 2. It is a circuit diagram of an example. 2... Receiving circuit, 3... Braun tube, 4... Amplitude modulation circuit, 5... Specific signal detection circuit.

Claims (1)

[Claims] 1 Partial brightness in an electronic display device characterized by detecting a specific symbol position on a display surface using an input video signal and enhancing the brightness of the input video signal during a period and timing of the peripheral position of the symbol Emphasis device.