JPS646548Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a CRT display device.

Although CRT displays have become indispensable in instrumentation systems, they generally have a disadvantage in that they have a short useful life due to their continuous display over long periods of time. For this reason, when the amount of information is small, often when the process is operating normally,
One possibility is to turn off the CRT's screen display switch. However, turning off the display switch has the disadvantage that it takes too much time for the image to be displayed on the display when it is needed.

In addition, in conventional CRT display devices, the brightness of the CRT screen can only be adjusted using an external adjustment terminal.
Brightness could not be adjusted without manual intervention by the operator.

The purpose of the present invention is to eliminate these conventional drawbacks, to provide a CRT display device that can be used with a longer CRT life, and that can make a strong impression on workers in an emergency.

The present invention achieves this objective by providing a brightness adjustment circuit that changes the brightness according to an alarm output signal from the central control unit.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The figure is a block diagram of one embodiment, in which a central control unit (CPU) 1 receives the process amount of the process, compares and calculates the set value, and issues an operation output, and when the process amount exceeds the predetermined set value and becomes an abnormal value. When this occurs, an alarm output is output. Furthermore, other display information and control information are output. The display information, color code, shift code, pattern information, etc. from this CPU1 are
It is displayed on the CRT 4 screen via the CRT controller section 2. CRT control section 2 is CPU1
It is provided to display various information from the CRT4 on the CRT4. Further, the alarm output is added to the alarm circuit 3, and an alarm is issued by means that appeal to the visual and auditory senses of the worker. 5 is a brightness adjustment circuit and external adjustment terminal 6
The brightness of the CRT 4 is varied by. If there is no abnormality in the process, the brightness of the CRT 4 is lowered. Also, the alarm output to alarm circuit 3 is from the CPU.
When the input signal is input, the brightness adjustment circuit 5 adjusts the brightness of the CRT 4 in the direction of increasing the brightness of the CRT 4.

Therefore, in this embodiment, when an alarm output is applied from the CPU to the alarm circuit, the luminance of the CRT 4 is increased from the lowered luminance state.

As described above, the present invention changes the brightness of the CRT according to the alarm output signal from the central control unit, so it has the effect of extending the life of the CRT and visually alerting workers to emergencies. It also leads to a reduction in power consumption.

Further, in one embodiment, the brightness is raised from a lowered brightness state, but the brightness may be lowered to such an extent that it is not displayed on the CRT and then raised.

[Brief explanation of drawings]

The figure is a block diagram of one embodiment of the present invention. 1...CPU, 2...CRT controller section, 3
...Alarm circuit, 4...CRT, 5...Brightness adjustment circuit, 6...External adjustment terminal.

Claims (1)

[Scope of utility model registration request] In a CRT display device that displays display information from a central control device on a CRT, a brightness adjustment circuit that normally puts the CRT in a low brightness state and increases the brightness of the CRT when an alarm output signal from the central control device is input. A CRT display device, characterized in that the CRT is used while extending its life.