JP2000098942A - Illumination signboard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination signboard which creates a gentle throbbing feel and beautiful stereoscopic feel and has a high customer luring effect by slowly and variously functionally changing the luminance at the time of light emission and at the time of extinction of the illumination signboard using LEDs(light emitting diodes), thereby respectively independently changing the luminance of the LED groups of many channels which are friendly to the human eyes and nerves and constitute characters and graphics. SOLUTION: The luminance of the LEDs 1 is controlled by forming the current flowing the LEDs 1 like pulses and changing the pulse width thereof. The changing of the pulse width is executed by digital processing to repeat the process of forming the pulses and the process of updating the data to determine the pulse width by using a CPU 2. The luminance may be rectilinearly changed if the periods of the process for forming the pulses are kept constant. The luminance may be changed like waves if the periods are changed to a sinusoidal functional form. The data to determine the pulse width is handled independently with each of the channels and, therefore, the increase or decrease of the luminance of every channel is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of illuminated signs and displays for displaying characters and figures using LEDs (light emitting diodes).

[0002]

2. Description of the Related Art Since LEDs have low power consumption, are easily connected in series and in parallel, and are relatively easy to use in combination, LEDs are used to display various characters and figures by light. Is becoming popular as an illuminated signboard. In order not to simply keep the red, blue, and green LEDs from emitting light, but to make the display more dynamic, a method of blinking these LEDs has become mainstream. However, blinking light displays are noticeable when compared to static displays, but overstimulate human nerves and cause disgust, and this is one of the environmental problems as “light pollution”. There was a problem that it is becoming.

[0003]

An object of the present invention is to form a character or a figure which is gentle to human eyes and nerves by slowly changing the brightness of the LED at the time of light emission and at the time of extinction into various functions. An object of the present invention is to provide an illuminated signboard having a great attraction effect by generating a gentle dynamism and a beautiful three-dimensional effect by independently changing the luminance of the LED groups of a large number of channels.

[0004]

In order to change the brightness of the LED, the value of the DC current flowing through the LED may be changed at any time, or the pulse width may be changed at any time using a pulse current. However, if these are combined with capacitors and resistors to slowly and independently control the brightness of the LED group of a large number of channels in an analog manner, there is a disadvantage that the circuit becomes very large. I could not do it. The present invention solves the above-mentioned problem by devising a digital data processing method for this purpose and digitally independently increasing and decreasing the pulse widths of the pulse currents of the LED groups of many channels.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The above-described digital data processing is carried out by repeating two steps of a step of generating a pulse current by a CPU and a step of generating data for determining the pulse width. The CPU activates the LED
The data of "1" and "0" which determine the ON / OFF of the LED are sequentially taken out from the memory of a certain area, and the ON / OFF of the LED group is turned on.
Write to the register that controls turning off. Since this is repeatedly performed, this is a process of generating the above-described pulse current. For example, if the data "1" continues, the pulse width increases accordingly. Until the data for determining the pulse width is updated, the pulse current having the constant pulse width continues to flow, so that the brightness of the LED does not change. Next, although the process is repeated, one process is completed in a short time, so that a free time is generated in the above-mentioned fixed period T. Utilizing this idle time, the data for determining the pulse width is slowly and gradually updated according to a program for changing the luminance of the LED group. This is the process. Thus, the pulse width of the pulse current flowing through the LED group of each channel changes slowly, and the luminance also changes slowly accordingly. On the other hand, the repetition frequency of the pulse itself is set to a high frequency that does not cause flicker to human eyes.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of an illuminated signboard according to the present invention. FIG. 1 is a diagram showing the arrangement of LED groups according to the embodiment, where 1 is one of several other LEDs.
Outer frame pattern and characters make up a group of LEDs,
5CH is formed from 1CH (channel). FIG.
FIG. 1 is a diagram showing a circuit diagram of an embodiment. A CPU 2 is connected to a memory 3, a register 4 and a timer 5. The five outputs of the register 4 are connected to the switch circuit 6, and switch the current of the LED group of all five channels on a channel basis. The LED is connected to a power supply E and a current limiting resistor 7 in series with other LEDs. For example, when the output of the first channel of the register 4 becomes “1”, L of 1CH including LED1 is
The ED group emits light.

Now, the operation of the embodiment will be described with reference to FIG. Reference numeral 8 denotes a first memory (RAM) for storing data for determining the pulse width;
The n data of “1” and “0” for the channels are stored. The CPU 2 counts the pulses from the timer 5, and collects the data of the five channels of the first memory 8 collectively from the first to the n-th register 4 at regular intervals of T time.
Output to When it reaches the nth, it starts again from the first. In this case, for example, the pulse current of the two-channel LED group becomes as shown in FIG. Since the data of the second channel is "1" up to the third, if this is left as it is, the emission luminance of the LED group of this channel remains at 3 / n of the maximum luminance.

On the other hand, a second memory (RAM) 9 stores "U" and "D" flags for each channel.
“U” means “UP”, and when this flag is “1”, the luminance increases. “D” means “DOWN”, and when this flag is “1”, the brightness decreases. The CPU 2 counts the number of times that the data of the first memory 8 is transferred to the register 4 once, and when the value reaches the predetermined number m, it takes a certain period of time thereafter to take the above-mentioned idle time. , The data of the first memory 8 is updated once. The method of updating is as follows. CPU2
Refers to the flag for each channel in the second memory 9, for example, since the “U” flag of channel 2 is “1”, the fourth data of channel 2 in the first memory 8 is changed from “0” to “0”. Update to "1". In this case, the pulse width of the pulse current 10 of the two channels is increased as indicated by 11, and
The brightness of the LED group of the channel, that is, in the case of the present embodiment, the brightness of the character "O" in FIG. 1 slightly increases. Similarly, the brightness of the character "P" on the three channels is slightly reduced.

By repeating this process, for example, the character "O" slowly reaches the maximum luminance. Then CP
U2 updates the flag in the second memory 9 in accordance with a predetermined program for producing a light-emitting pattern of a character or a figure, and enters the next production mode. By changing the value of n, the fineness of the luminance change can be varied. Further, by changing the value of m, the speed of the luminance change can be freely changed. Therefore, although not shown in FIG. 2, if a switch is connected to the CPU 2 via an I / O port so that the value of m can be selected, the light emitting pattern production speed can be selected according to the taste and situation. It goes without saying that you can select. Alternatively, the same effect can be obtained by changing the oscillation frequency of the timer 5 with a variable resistor.

According to the above-described method, the brightness of the LED changes slowly and linearly as compared with the conventional illuminated signboard that blinks the light emission of the LED. Although the stimulus to the eyes is remarkably small compared to the blinking by itself, the present invention should be particularly noted. In addition, the following special brightness change control method can be adopted. So I will explain this. It is known that "stimuli perceived by the stimulus" in the natural world, such as the human eye, respond to natural logarithms. Therefore, it can be said that it is more suitable to change the light brightness in an exponential function, a series function, or a sine wave function than to change linearly. Then, the data of the first memory 8 is stored in the register 4,
The time of the cycle T to be transferred to generate the pulse current is changed according to the above function in the order of 1 to n. Then, the change is small while the brightness of the LED light is small, and the change is large when the brightness is large, so that a light pattern closer to a natural phenomenon can be drawn.

The circuit and its configuration can be variously changed in accordance with the gist of the present invention without being restricted to this embodiment. For example, if a one-chip computer in which a timer, a memory, and a register are housed in the same chip is used, a smaller circuit can be formed. If the current capacity of the register is large enough to be necessary, the switch circuit can be omitted. Furthermore, it is also possible to connect to an optical sensor, a sound sensor, a human sensor, or the like, to turn on / off the LED group or change the light pattern.

[0012]

According to the present invention described above, first, L
The ED's illuminated signboard will no longer flicker and give people more stimulation than necessary. The uproar that many children were hospitalized by the strong flashing light of TV is also new to memory, and the signboard whose brightness changes slowly slowly is not only eye-friendly but also heart-friendly. One of the remarkable effects is that when a large number of LED groups perform an effect such as increasing the luminance on the one hand and decreasing the luminance on the other hand, a three-dimensional effect is created in the light pattern. The elegantly illuminated signboard has an atmosphere as if talking to the heart of the person and has a great effect on attracting customers.

[0013]

[Brief description of the drawings]

FIG. 1 is a diagram showing an arrangement of LED groups according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of an embodiment according to the present invention.

FIG. 3 is a diagram showing data processing and an LED current waveform by a circuit according to an embodiment of the present invention.

[Explanation of symbols]

1 LED, 2 CPU, 3 memory, 4 register,
5 timer, 6 switch circuit, 7 current limiting resistor
8: First memory, 9: Second memory, 10: Pulse current waveform of LED group of 2 channels, 11: Arrow indicating increase in pulse width

Claims (2)

[Claims] An LED group which is connected to a DC power supply for each channel and emits light to display a character or a figure;
A switch circuit having a function of generating a pulse current by switching the current of the ED group for each channel; a register for controlling the switch circuit; a CPU for rewriting the data in the register; And a memory for storing a program and data for changing the pulse width of the pulse current by changing the pulse current, and a timer connected to the CPU. An illuminated signboard comprising a multi-channel LED group, characterized by being changed. 2. The electric signboard according to claim 1, wherein
An illuminated signboard characterized by increasing or decreasing a change in light emission luminance of a group not in a linear manner but in an exponential function, a series function, or a sine wave function.