JPH11296141A - Display device for elevator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display characters with stable luminance even at the time of luminance decrease caused by the degradation of an LED with the passage of time by providing a means for automatically correcting the degradation of luminance of display characters with the passage of time corresponding to the working time of an elevator. SOLUTION: When floor display data are inputted to a communication circuit 17, based on these data, an MPU 11 displays characters on floor indicator and direction lamp 14 as a dot type LED display. Besides, when a hall button 19 is pressed, an input circuit 18 converts a signal level and inputs it to the MPU 11. A timer 15 counts the time supplying power to the dot type display, after the supply of power is cut off, counting is stopped and count data are held. While referring to the count data of the timer 15, based on the change of luminance caused by the degradation of the dot type LED element with the passage of time, the luminance of display characters at present is calculated. The pulse width of an output permit signal 24 is extended just for the degradation in the luminance of display characters from this result and the luminance of display characters is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for displaying operation information of an elevator, and in particular, it is possible to automatically correct the aging deterioration of the luminance of the display characters of a dot type LED display by the operation time of the elevator. And an elevator display.

[0002]

2. Description of the Related Art In a dot-type LED display, in order to light a light emitting element by time division control, a driving method of passing a pulse current intermittently with a fixed time width is used for the light emitting element.

In such a driving method, a current is intermittently supplied to the light emitting element, so that the light emitting state of the light emitting element blinks due to the intermittent current, but is recognized by the naked eye as apparently continuous light emission due to an afterimage phenomenon.

For example, in the technique disclosed in Japanese Patent Application Laid-Open No. Sho 63-315479, since the pulse width and the LED drive current are both constant, the brightness of the displayed characters is also constant.

[0005]

In the above prior art, since the pulse width for driving the display and the LED driving current are both constant, it is difficult to change the brightness of the displayed characters.

An object of the present invention is to make it possible to change the brightness of a display character.

Another object of the present invention is to automatically correct the aging deterioration of the luminance of the display characters according to the operating time of the elevator,
An object of the present invention is to provide an elevator display device capable of displaying characters at a stable luminance even when the luminance is reduced due to aging deterioration of D.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to provide a configuration in which the pulse width can be changed while the driving current of the LED remains constant, and the pulse width is changed according to the operation time of the elevator, thereby reducing the brightness of the displayed characters. change.

That is, the display device of the elevator automatically corrects the aging deterioration of the luminance of the displayed characters according to the operation time of the elevator. As a result, even if the brightness of the displayed characters does not decrease due to the deterioration of the LEDs over time, it is possible to realize an elevator display device in which the displayed characters are easy to see.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall structure of the elevator. When the hall button 19 is pressed, the information is transmitted to the control panel 1 via the transmission line 5. Upon receiving the elevator call information, the control panel 1 operates in response to the floor where the elevator call has occurred. Further, the dot type LED display 7 displays the current position of the car 3.

FIG. 2 shows a control circuit configuration of the dot type LED display. When the floor display data sent through the transmission line is input to the communication circuit 17, the MPU 11 is based on the data.
Displays characters on the floor indicator light and direction light 14 which are dot type LED displays. When the Hall button 19 is pressed, the signal level is converted by the input circuit 18 and M
It is input to PU11.

Then, the MPU 11 is configured to transmit the information of the hole button 19 to the transmission path via the communication circuit 17. The timer 15 counts the time during which power is supplied to the dot-type LED display 7, and stops the power supply when the power supply is cut off to hold the count data.

FIG. 3 shows the appearance of a dot-type LED display element. A plurality of display elements 14a are arranged to form a floor indicator light and a direction light 14.

The operation of displaying the floor indicator light and the direction light 14 is performed by the common select signal 2 from the MPU 11.
1 to 23, a plurality of segment signals 25, and an output permission signal 24 are output to turn on one row selected by the common select signal of the floor indicator light and the direction light 14. This operation displays all the characters while switching the lines sequentially in a time-division manner.

FIG. 4 shows common select signals 21 to 23,
This shows the timing of the segment signal 25 and the output permission signal 24. The LED lighting timing is the same as the pulse width t of the output permission signal 24.

FIG. 5 shows an example of a luminance change due to aging of the dot-type LED display element 14a. The luminance of the display character of the dot-type LED display element 14a at the start of operation is shown.
If 100% (initial value), 10 years later the initial value of 5
It can be seen that the luminance changes linearly to 0%.

Referring to the count data of the timer 15, the luminance of the current display character can be calculated based on the luminance change (FIG. 5) due to the aging deterioration of the dot type LED element. From this result, the pulse width t of the output permission signal 24 is increased by an amount corresponding to the deterioration of the luminance of the display character, thereby increasing the luminance of the display character.

Here, if the pulse width t of the output permission signal 24 is made longer, the brightness of the displayed characters becomes brighter. Conversely, when the pulse width t of the output permission signal 24 is shortened, the brightness of the displayed character becomes dark.

According to the present embodiment, the aging of displayed characters can be automatically corrected by the operating time of the elevator, and a display device which is easy to see can be realized.

[0021]

According to the present embodiment, since the aging deterioration of the display character brightness is automatically corrected according to the operation time of the elevator, the brightness of the display character at the start of operation can be ensured even when the system is operated for a long time. A display device in which displayed characters are easy to see can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an entire elevator according to an embodiment of the present invention.

FIG. 2 is a control circuit diagram illustrating a control circuit configuration of the dot type LED display of FIG. 1;

FIG. 3 is a front view illustrating the appearance of the dot-type LED display device of FIG. 2;

FIG. 4 is a control timing chart of the dot type LED display of the present invention.

FIG. 5 is a luminance change characteristic diagram of the dot-type LED display element of the present invention due to aging.

[Explanation of symbols]

1 ... control panel, 2 ... induction motor, 3 ... basket, 4
... balance weight, 5 ... transmission line, 7 ... dot type LED display, 11 ... MPU, 12 ... common driver circuit, 13 ...
Segment driver circuit, 14 floor indicator and direction light, 14a dot-type LED element, 15 timer, 17
... communication circuit, 18 ... input circuit, 19 ... hole button, 2
1 to 23: common select signal, 24: output permission signal,
25 ... Segment signal.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masayuki Hirose 1070 Ma, Hitachinaka City, Ibaraki Prefecture Inside Mito Plant of Hitachi, Ltd. Katsuta Hitachi Mito Engineering Co., Ltd.

Claims (1)

[Claims] 1. A dot-type LED display provided in each elevator hall or in a car, which displays a car position and a driving direction, automatically corrects the aging deterioration of the luminance of display characters according to the operation time of the elevator. A display device for an elevator, characterized by having means.