JPH01142795A - Display device - Google Patents

Abstract

PURPOSE: To improve the usefulness of a two-color light emitting element by always preferentially emitting one color light of the two-color light emitting element at the time of the simultaneous occurrence of two phenomena in an electronic apparatus device. CONSTITUTION: Signals X and Y are outputted in accordance with the occurrence of two kinds of phenomena in the electronic apparatus device, and a red light emitting element 1a of a two-color light emitting element 1 emits light by the signal X, and a green light emitting element 1b emits light by the signal Y. When the signal X is '1' and the signal Y is '0', red is set to '1' and green is set to '0' independently of the logical level of a clock signal CK, and only the element 1a emits light. When the signal X is '0' and the signal Y is '1', only the element 1b emits light. When signals X and Y are '1' together, only the element 1a preferentially emits light if the signal CK is '1', but only the element 1b preferentiall emits light if the signal CK is '0'.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a display device for displaying the occurrence of a phenomenon in an electronic device using a two-color light emitting element.

(Prior Art) Conventionally, in electronic devices such as information processing devices, light emitting elements such as light emitting diodes have been used as means for indicating the occurrence of phenomena such as mode states.

Recently, two-color light-emitting elements such as two-color light-emitting diodes have been used in place of the above-mentioned monochromatic light-emitting elements. It is said that it is possible to confirm the occurrence of two types of phenomena using one light-emitting display.

By the way, in the above-mentioned two-color light-emitting element, it is prohibited to emit light in two colors at the same time since this would exceed the rated current of the two-color light-emitting element. From this,
For example, such a two-color light-emitting element cannot be used in an electronic device in which phenomenon A and phenomenon B can occur simultaneously.

(Problems to be Solved by the Invention) The present invention is intended to solve such problems, and when two phenomena occur simultaneously in an electronic device, one of the two-color light emitting elements always It is an object of the present invention to provide a display device that can emit light with priority given to one color and can improve the usability of a two-color light emitting element.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a display device for displaying the occurrence of a phenomenon in an electronic device using a two-color light emitting element. Two signal input terminals for inputting signals according to the occurrence of a phenomenon, a control signal input terminal for inputting control signals, and outputting signals for causing the two-color light emitting element to emit light for each color. For 2
When a signal at a level that causes the two-color light emitting element to emit light is input to each of the two signal input terminals, two signals are output according to the logic level of the control signal input to the control signal input terminal. It is equipped with a logic circuit that prioritizes one of the outputs from the output end and sets it to a level that causes the two-color light emitting element to emit light.

(Function) In the display device of the present invention, when a signal at a level that causes the two-color light emitting element to emit light is input to the two signal input terminals, the logic circuit determines the logic of the control signal input to the control signal input terminal. Depending on the level, one of the outputs from the two signal output terminals is prioritized to a level that causes the two-color light-emitting element to emit light, so when two phenomena occur simultaneously in an electronic device, the two-color light-emitting element always It is possible to emit light with priority to one of the colors, and the usability of the two-color light emitting element can be improved.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing a light emission control circuit for a two-color light emitting element in a display device according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a two-color light-emitting element such as a two-color light-emitting diode integrally comprising two light-emitting elements 1a and 1b that emit red and green light, respectively; 2a and 2;
b is a current supply switching transistor corresponding to each light emitting element 1a, 1b, and 3 is a current limiting resistor.

Further, X and Y are signals respectively output in response to the occurrence of two types of phenomena in an electronic device (not shown), and X is a signal for causing the red light emitting element 1a of the two-color light emitting element 1 to emit light. The signal Y is a signal for causing the light emitting element 1b on the green light emitting side to emit light. CK is a clock signal used as a control signal in this embodiment.

Furthermore, 4 is for giving priority to one of the signals output to each switching transistor 2a, 2b to set it to a high level according to the logic level of the clock signal CK when both input signals X and Y are at a high level. The logic circuit includes three inverters 5a, 5b, 5C, two OR gates 6a, 6b, and two AND gates 7a, 7.
It consists of b.

(Hereafter, margin) Next, a truth table of this logic circuit 4 is shown.

Truth table In addition, in this table, if red is "1", light emitting element 1
When "a" emits light and green is "1", it means that the light emitting element 1b emits light.

As can be seen from this table, signal X is "1" and signal Y is "0".
'', red becomes "1" and green becomes "0" regardless of the logic level of the clock signal CK, and as a result, the light emitting element 1a
Only the light emits light. Also, signal X is “0” and signal Y is “1”
In this case, red becomes "0" and green becomes "1" regardless of the logic level of the clock signal CK, and the light emitting element 1b emits light.

Further, when the clock signal CK is "1" when both the signal X and the signal Y are "1", red becomes "1" and green becomes "0", and only the light emitting element 1a emits light preferentially. On the other hand, when the clock signal CK is "0", red is "0" and green is "0".
1'', and only the light emitting element 1b emits light preferentially.

Therefore, in the display device equipped with this logic circuit 4, each light emitting element 1a of the two-color light emitting element 1,
When a phenomenon that causes both of the light emitting elements 1b to emit light does not occur simultaneously, the light emitting elements 1a and 1b can be made to emit light alternately according to the logic level of the clock signal CK.

Furthermore, in this logic circuit 4, if the clock signal CK is fixed to "1", both the signal X and the signal Y become "1".
At this time, only the red light emitting element 1a can be caused to emit light continuously, and if the clock signal CK is fixed to rQ, it is possible to make only the green light emitting element 1b continuously emit light.

In this embodiment, the clock signal CK is used as the control signal input to the logic circuit 4, but if this is the output of the astable multivibrator, when both the signal X and the signal Y are "1", , it becomes possible to cause the light emitting elements 1a and 1b to emit light alternately at the same time pitch. Note that the wavelength/time ratio of the clock signal in this case can be changed by changing the clock constant of the astable multivibrator.

[Effects of the Invention] As explained above, according to the present invention, when two phenomena occur simultaneously in an electronic device, one of the colors in the two-color light emitting element can always be emitted with priority. , the usability of the two-color light emitting device can be improved.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram for explaining the configuration of a light emission control circuit for a two-color light emitting element in a display device according to an embodiment of the present invention. 1... Two-color light emitting element, 1a, 1b... Light emitting element, 4
...Logic circuit, X, Y...signal, CK...clock signal.

Claims (3)

[Claims] (1) A display device for displaying the occurrence of a phenomenon in an electronic device using a two-color light emitting element, which has two signal input terminals for respectively inputting signals corresponding to the occurrence of the phenomenon, and a control signal. It has a control signal input terminal for inputting a control signal, and two signal output terminals for respectively outputting a signal for causing the two-color light emitting element to emit light for each color,
When a signal at a level that causes the two-color light emitting element to emit light is input to the two signal input terminals, the two signals are output according to the logic level of the control signal input to the control signal input terminal.
1. A display device comprising a logic circuit that prioritizes one of the outputs of the two signal output terminals and sets it to the above level. (2) The control signal is a clock signal, and one of the signals from the two signal output terminals is fixed at a level that causes the two-color light emitting element to emit light. Display device according to scope 1. (3) The control signal is an output of an astable multivibrator, and the signals from the two signal output terminals are set to levels that cause the two-color light emitting element to emit light in a time-sharing manner. Display device according to scope 1.