JPH09297554A - Led display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make display easily visible by adopting the constitution to change the light emitting colors of LED units of a green display in accordance with the sensor signals detected by an illuminance sensor, thereby changing the green light emitting LED units to red or orange of higher luminance when the ambient illuminance is high. SOLUTION: The LED display device 1 contains an electrical control means in a case 2 and has an LED display panel 3 and an illuminance sensor 5. The display device is installed at, for example, a platform and displays train names, departure time, etc. The first line L1, second line L2 of such LED display panel 3 are so set that, for example, the characters A to F of the first line L1 are displayed green and the characters G to L of the second line L2 are displayed red. When the strong direct rays of the sun fall onto the LED display panel 3, the illuminance sensor 5 detects a light quantity and the control means changes the colors of the LED display panel 3. The green display of A to F of the first line L1 is changed to, for example, orange and the luminance thereof is made equal to or higher than the luminance of G to L of the red display of the second line L2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED display device comprising a light emitting diode (LED), and more particularly to an LE display device.
The present invention relates to an LED display device whose emission color or brightness can be changed according to the brightness of the surroundings of the surface of a D display panel.

[0002]

2. Description of the Related Art A conventional LED display device installed in a station waiting room, a station yard, a platform or the like has a single LED unit formed by integrating a red LED element and a green LED element. It has LED display panels arranged in a matrix.

The LED unit is formed as a three-terminal component in which the anode or cathode of the red LED element and the green LED element is used as a common terminal. When a forward current is applied to the red LED element, the red and green LED elements are ordered. When a directional current is passed, a forward current is simultaneously passed through the green, red, and green LED elements, so that orange (a mixed color of red and green) is made to emit light, and one component emits three colors independently. be able to.

Therefore, a plurality of the LED units are arranged in a matrix to form an LED display panel, and, for example, a plurality of train names and departure times to be set on the platform and to depart are repeatedly displayed in the order of orange, red and green. Or, it has been put to practical use to display the train name that will be departing next time in orange for each platform, the departure time in red, and the stop station in green.

[0005]

In the conventional LED display device, the current cannot be adjusted because the current flowing through the LED unit is constant, and when the LED display panel is exposed to strong direct sunlight such as the sun. , The display may be difficult to see.

Further, even if the current supplied to the LED unit is constant, the brightness of the LED elements tends to decrease in the order of orange, red, and green. Even if the current flowing through the LED unit is changed by the same value, the brightness of orange, red, and green is not balanced, and there is a problem that the display is difficult to see.

The present invention has been made to solve such a problem, and a first object thereof is to change a green light emitting LED unit to red or orange which has higher brightness when the ambient illuminance is high. Another object of the present invention is to provide an LED display device that can make the display easier to see.

A second object is to weight and change the brightness of the orange, red, and green LED units corresponding to changes in the ambient illuminance, and to make the orange, red, and green emission colors almost the same. An object is to provide an LED display device that can be made bright.

[0009]

In order to solve the above problems, the control means of the LED display device according to the present invention changes the emission color of the LED unit for green display based on the sensor signal detected by the illuminance sensor. Characterize.

Since the control means of the LED display device according to the present invention changes the emission color of the LED unit for green display based on the sensor signal detected by the illuminance sensor, when the surroundings are too bright, the LED for green display is changed. You can increase the brightness by changing the emission color of the unit to orange or red.

Further, the control means of the LED display device according to the present invention comprises a comparing means for comparing the sensor signal with a reference value, a color changing means for generating a color changing signal based on the comparison signal from the comparing means, and a color changing means. It is characterized in that a color setting means for changing the setting of the emission color by a signal is provided.

The control means of the LED display device according to the present invention comprises a comparing means for comparing the sensor signal with a reference value, a color changing means for generating a color changing signal based on the comparison signal from the comparing means, and a color changing signal. Since the color setting means for changing the setting of the light emission color is provided, the brightness can be increased by switching the light emission color of the green LED unit to orange or red when the surroundings are too bright.

Further, the control means of the LED display device according to the present invention is characterized in that the brightness is changed according to the emission color of the LED unit based on the sensor signal detected by the illuminance sensor.

The control means of the LED display device according to the present invention uses the LED based on the sensor signal detected by the illuminance sensor.
Since the brightness is changed according to the emission color of the unit, it is possible to adjust the brightness of each of the LED units for orange, red, and green to be the same according to the ambient brightness.

Further, the control means of the LED display device according to the present invention generates a luminance signal weighted for each emission color corresponding to the comparison means for comparing the sensor signal with the reference value and the deviation between the reference value and the sensor signal. It is characterized by comprising a brightness setting means.

The control means of the LED display device according to the present invention is a comparison means for comparing the sensor signal with a reference value, and a brightness setting for generating a brightness signal corresponding to a deviation between the reference value and the sensor signal and weighted for each emission color. Since it is equipped with means, L of each of orange, red, and green display is provided according to the ambient brightness.
The brightness of the ED unit can be changed by weighting and adjusted to the same brightness.

Further, the LED display device according to the present invention is characterized in that the illuminance sensor is arranged near the display surface of the LED display panel.

In the LED display device according to the present invention, since the illuminance sensor is arranged near the display surface of the LED display panel,
It is possible to accurately detect the illuminance on the surface of the LED unit displaying orange, red and green.

[0019]

Embodiments of the present invention will be described below with reference to the accompanying drawings. It should be noted that the present invention provides an LED display device capable of making the display easier to see by changing green, which has low luminance of emission color, to orange or red, particularly when the display is difficult to see because the periphery of the surface of the LED display panel is too bright. To do.

Further, according to the present invention, when the surroundings of the surface of the LED display panel are too bright and the display is difficult to see, the brightness of the orange, red and green displays is changed according to the brightness to adjust the brightness to the same brightness. An LED display device that can be easily viewed is provided.

FIG. 1 is an external view of an LED display device according to the present invention. In FIG. 1, an LED display device 1 has an electric control means built in a case 2, an LED display panel 3 and an illuminance sensor 5, and for example, a plurality of train names and departure times which are installed on a platform and which depart. Is displayed.

The LED display panel 3 includes an LED unit 4
Are arranged in a matrix and, for example, 2 rows ×
6 columns of characters are displayed.

FIG. 2 is a block diagram of an embodiment of the LED unit. In FIG. 2, the LED unit 4 includes two LEs.
D (light emitting diode) elements LED1 and LED2 are sealed in a case, for example, LED (light emitting diode) element L
The ED1 is formed to emit green (G) and the LED (light emitting diode) element LED2 is formed to emit red (R).

The LED unit 4 is composed of three terminals of an external connection terminal anode A ₁ , anode A ₂ and cathode C. When a positive (+ polarity) power source is applied between the anode A ₁ and the cathode C, the LED 1 becomes green. (G) emits light, and when a positive (+) polarity power supply is applied between the anode A ₂ and the cathode C, the LED 2 emits red (R).

Further, the positive polarity (+ polarity) is simultaneously applied between the anode A ₁ and the cathode C and between the anode A ₂ and the cathode C.
LED1 is green (G), LED2 is
Simultaneously emit red (R), and the LED unit 4 emits orange (A).

Therefore, the LED unit 4 can display three colors of green (G), red (R) and orange (A) by switching the power supply applied to the anodes A ₁ and A ₂ . The green (G) can be obtained by controlling the current flowing through the external connection terminals anode A ₁ and anode A ₂ to the LED1 and LED2 via a resistor, or by driving the LED1 and LED2 with a constant current to control the constant current. The brightness of red (R) and orange (A) can be adjusted.

The illuminance sensor 5 is composed of, for example, a photovoltaic sensor such as a photodiode or a phototransistor and is arranged on the display surface of the LED display panel 3 to detect the illuminance of a light beam incident from the surface of the LED display panel 3. .

FIG. 3 is a block diagram of the essential parts of the LED display device according to the present invention. In FIG. 3, the control means 7
2 controls the light emission color and lighting of the LED display panel 3 shown in FIG. 1, and forms the LED display panel 3 based on the sensor signal K _A detected by the illuminance sensor 5. ) Display LED1 is switched to red (R) display LED2 to change the emission color from green (G) to red (R), or LED unit 4 displays green (G) display LED1 and red (R). ) By simultaneously driving the LED 2 for display to change the emission color from green (G) to orange (A), it is possible to see when the LED display panel 3 shown in FIG. Red (R) or orange (A) that makes it easier to see the green (G) display
Change to

The control means 7 is composed of various arithmetic means, processing means, etc. based on a microprocessor, and the A / D conversion means 1
1, comparison means 12, color changing means 13, display setting means 1
4, a color setting unit 15 and a driving unit 16.

The A-D conversion means 11 is composed of an A-D converter, converts the analog sensor signal K _A detected by the illuminance sensor 5 into digital data at a predetermined timing, and outputs the digital sensor signal K _D to the comparison means 12. Supply. In addition,
The sensor signal K _A increases in response to an increase in the amount of light such as direct sunlight detected by the illuminance sensor 5.

The comparing means 12 is composed of a comparator using, for example, a differential amplifier, and compares the digital sensor signal K _D supplied from the AD converting means 11 with a preset reference value K _R. , If the sensor signal K _D exceeds the reference value K _R (K _D > K _R ), for example, an H level comparison signal H _O is provided to the color changing means 13. The comparison means 12
Is a Schmitt trigger type (provided that it has hysteresis characteristics).
Configure to prohibit _O output.

The color changing means 13 is composed of, for example, a state detecting means such as a flip-flop, and operates at the rising edge of the H level comparison signal H _O provided from the comparing means 12 to, for example, an H level control signal (color). The change signal) C _O is supplied to the color setting means 15. The color changing unit 13 is composed of an encoder such as an encoder, and based on the H-level comparison signal H _O provided from the comparing unit 12, for example, a binary coded control signal (color change signal) C _O. Is supplied to the color setting means 15.

The display setting means 14 is composed of, for example, a memory such as a ROM, and outputs a designation signal P _S for designating characters to be displayed on the LED display panel 3 and the size and color of the characters based on preset software programming. Color setting means 15
To provide. The designation signal P _S is the LED display panel 3
It includes character information and color information of display color to be displayed on the display.

The color setting means 15 is composed of a plurality of memories such as ROM, PWM (pulse width modulation) signal generating means, constant current setting signal generating means, serial-parallel converting means, etc., and is provided from the display setting means 14. a plurality of parallel setting signal C _S corresponding to the character and color based on the designation signal P _S that
Are provided to the driving means 16.

Further, the color setting means 15 is provided with a switching means for switching the setting signal C _S and, for example, green (corresponding to a color based on the control signal (color change signal) C _O supplied from the color changing means 13 The control signal C _O corresponding to G) is switched to the parallel setting signal C _S corresponding to red (R) or orange (A).

The driving means 16 is composed of a PWM driving circuit or a constant current circuit for driving the respective LED units 4 arranged in a matrix on the LED display panel 3, and the characters provided from the color setting means 15 and A parallel driving signal D _S is generated based on a plurality of parallel setting signals C _S corresponding to colors, and a plurality of LEDs corresponding to green (G), red (R) and orange (A) are generated by the parallel driving signal D _S. The unit 4 is driven at the same time, and the LED display panel 3
The characters, the size of the characters, and the color preset in the display setting means 14 are displayed.

When the control signal C _O is output from the color changing unit 13, the driving unit 16 changes the parallel setting signal C _S corresponding to green (G) to red (R) or orange (A). Correspondingly switched parallel setting signal C _S
Drive a plurality of LED units 4 simultaneously based on
The green (G) display displayed on the ED display panel 3 is changed to a red (R) display or an orange (A) display.

FIG. 4 is an explanatory view of state changes of the LED display device according to the present invention. (A) figure is a normal state explanatory diagram,
FIG. 6B shows a state explanatory view of the display color change. In the figure, in the first line L1 (G) and the second line L2 (R) of the LED display panel 3, the letters A to F on the first line are displayed in green (G), and the second line G is displayed. It is assumed that the letters ~ L are set to red (R).

Generally, the brightness of the characters A to F displayed in green (G) is lower than that of the characters G to L displayed in red (R) if the current flowing through the LED is constant due to the properties of the material of the LED. If the LED display panel 3 is exposed to direct sunlight such as the sun, it tends to be difficult to see.

In the state of (a), strong direct sunlight L _E is L
When it hits the ED display panel 3, the illuminance sensor 5 shown in FIG. 3 detects the amount of light, and the control means 7 changes the color of the LED display panel 3. Therefore, as shown in FIG.
The color display of characters (A) to (F) displayed in green (G) in (G) is changed to, for example, orange (A), and is equivalent to the brightness of characters (G) to L displayed in red (R) on the second line L2 (R). The above luminance is provided, and it is easy to see.

As described above, the control means of the LED display device according to the present invention changes the emission color of the LED unit for green display based on the sensor signal detected by the illuminance sensor. Luminance can be increased by changing the emission color of the green LED unit to orange or red.

Further, the control means 7 of the LED display device 1 according to the present invention compares the sensor signal with a reference value, and the color change signal generating the color change signal on the basis of the comparison signal from the comparison means 12. Since the means 13 and the color setting means 15 for switching the setting of the emission color by the color change signal are provided,
If the surroundings are too bright, the emission color of the green LED unit can be changed to orange or red to increase the brightness.

Next, a description will be given of an LED display device capable of adjusting the brightness of each of green (G), red (R) and orange (A) in accordance with the emission color when the surroundings are too bright.

FIG. 5 is a block diagram showing the main part of another embodiment of the LED display device according to the present invention. In FIG.
The LED display device 10 includes a control unit 8, and the control unit 8 includes an A / D conversion unit 11, a display setting unit 14, a color setting unit 15, a comparison unit 21, a brightness setting unit 22, and a driving unit 23.

The A-D conversion means 11, the display setting means 14, and the color setting means 15 have the same configurations and functions as those described with reference to FIG.

The comparing means 21 is composed of deviation calculating means, etc.,
Deviation ΔH (= K _R between the preset reference value K _R and the digital sensor signal K _D supplied from the A / D conversion means 11
-K _D ) is calculated and the deviation ΔH exceeds 0 (ΔH> 0)
In this case, the deviation signal ΔH is provided to the brightness setting means 22.

The brightness setting means 22 is composed of a memory such as a ROM, and has a deviation ΔH (=
K _R -K _D) green (G) corresponding to red (R) and respective weighted coefficient G _O orange _{(A), R O, A} O
When the deviation signal ΔH is provided from the comparison means 21, the coefficient data G _O , R _O , A _O corresponding to the deviation signal ΔH is read out from the data table and is supplied to the driving means 23 as a luminance signal. Supply.

It is to be noted that the coefficient data G _O , R _O and A _O are set to R _O = α * A _O and G _O = β * A _O , where β>α> 1, assuming that A _O = 1. LED display panel 3
Arbitrary deviation ΔH (= K _R depending on the amount of sunlight L _E
-K _D ) is set so that the green (G), red (R), and orange (A) luminances of the LED unit 4 are equal.

The driving means 23 drives the respective LED units 4 arranged in a matrix on the LED display panel 3, so that the coefficient data G _O , R _O , A _O (luminance signal) supplied from the luminance setting means 22 is supplied. ), A plurality of parallel setting signals corresponding to the characters and colors provided from the color setting means 15 are configured by, for example, a PWM drive circuit whose pulse width is changed or a constant current circuit whose current value is changed. C _N
A parallel drive signal D _V is generated on the basis of the parallel drive signal D _V, and a plurality of corresponding LED units 4 are simultaneously driven by the parallel drive signal D _V to display the characters and colors preset in the display setting means 14 on the LED display panel 3. To do.

LEDs set to green (G), red (R) and orange (A) based on the weighted coefficient data G _O , R _O and A _O (luminance signal) supplied from the luminance setting means 22. Since the unit 4 is driven, the green (G), red (R), and orange (A) emission colors of the LED display panel 3 have the same brightness corresponding to the brightness of the periphery (especially the front surface) of the LED display panel 3. Can be displayed with.

FIG. 6 shows an explanatory view of the state change of the LED display device according to the present invention. 6, in the first line L1 (G) and the second line L2 (R) of the display panel 3, the letters A to F on the first line are displayed in green (G), and the letters G to L on the second line are displayed. It is assumed that the character is set to red (R).

Due to the brightness adjusting action of the control device 8, the letters A to F on the first line are displayed in green (G) and the letters G to L on the second line are displayed in red (R). . When strong direct sunlight L _E hits the LED display panel 3, the illuminance sensor 5 shown in FIG. 3 detects the amount of light, and the control means 8 weights the coefficients G _O and R for green (G) and red (R), respectively. _{With O} , the brightness of the green (G) display on the first line and the red (R) display on the second line is set to the same, so the green (G) display and the red (R) display are set.
The display can be displayed with the same brightness.

As described above, the control means of the LED display device according to the present invention changes the brightness in accordance with the emission color of the LED unit based on the sensor signal detected by the illuminance sensor. The brightness of each LED unit for orange, red and green display can be adjusted to the same.

Further, the control means of the LED display device according to the present invention generates a luminance signal weighted for each emission color corresponding to the comparing means for comparing the sensor signal with the reference value and the deviation between the reference value and the sensor signal. Since the brightness setting means is provided, the brightness of each of the LED units for orange, red and green can be weighted and changed according to the brightness of the surroundings to be adjusted to the same brightness.

Further, in the LED display device according to the present invention, since the illuminance sensor is arranged near the display surface of the LED display panel, the illuminance on the surface of the LED unit for orange, red and green can be accurately detected.

[0056]

As described above, the LE according to the present invention is
The control means of the D display device changes the emission color of the LED unit for green display based on the sensor signal detected by the illuminance sensor, and when the surroundings are too bright, the emission color of the LED unit for green display is high in brightness. Since it is changed to orange or red, the display can be made easier to see.

Further, the control means of the LED display device according to the present invention comprises a comparing means for comparing the sensor signal with a reference value, a color changing means for generating a color changing signal based on the comparison signal from the comparing means, and a color changing means. Equipped with a color setting unit that switches the setting of the emission color according to the signal, if the surroundings are too bright,
Since the emission color of the green LED unit is changed to orange or red to increase the brightness, bright display can be achieved.

Further, since the control means of the LED display device according to the present invention changes the brightness according to the light emission color of the LED unit on the basis of the sensor signal detected by the illuminance sensor, the orange color according to the ambient brightness, The brightness of each LED unit for red and green displays can be adjusted to be the same, and the orange, red, and green displays can be made to have the same brightness for easy viewing.

Further, the control means of the LED display device according to the present invention generates a luminance signal weighted for each emission color corresponding to the comparing means for comparing the sensor signal with the reference value and the deviation between the reference value and the sensor signal. A brightness setting means is provided, and L of each of orange, red, and green display is provided according to ambient brightness.
The brightness of the ED unit can be changed by weighting and adjusted to the same brightness, and a bright and easy-to-see display can be made.

The LED display device according to the present invention is
Since the brightness is increased only when the surroundings (particularly the surface of the LED display panel) is too bright, it is not necessary to constantly supply a large current to the device, and power can be saved.

Further, in the LED display device according to the present invention, the illuminance sensor is arranged in the vicinity of the display surface of the LED display panel and the illuminance on the surface of the LED unit for orange, red and green is accurately detected. It is possible to accurately change or change the light emission brightness.

Therefore, it is possible to provide an LED display device capable of providing a bright and easy-to-see display and saving power even when exposed to strong light such as the sun.

[Brief description of drawings]

FIG. 1 is an external view of an LED display device according to the present invention.

FIG. 2 is a block diagram of an embodiment of an LED unit.

FIG. 3 is a block diagram of a main part of an LED display device according to the present invention.

FIG. 4 is an explanatory view of a state change of the LED display device according to the present invention.

FIG. 5 is a block diagram of the main part of another embodiment of the LED display device according to the present invention.

FIG. 6 is a block diagram of the main part of another embodiment of the LED display device according to the present invention.

[Explanation of symbols]

1, 10 ... LED display device, 2 ... case, 3 ... LED display panel, 4 ... LED unit, 5 ... illuminance sensor, 7,
8 ... Control means, 11 ... AD conversion means, 12, 21 ... Comparison means, 13 ... Color changing means, 14 ... Display setting means, 15
... color setting means, 16 and 23 ... drive unit, 22 ... brightness setting means, C _N, C _S ... setting signal, C _O ... control signal, D _S, D _V
... drive _{signal, G O, R O, A} O ... coefficient data, H _O ... comparison _{signals, ΔH (= K R -K D} ) ... deviation signal, K _A, K _D ... sensor signal, K _R ... reference value, LED1, LED2 ... Light emitting diode element, L _E ... Direct sunlight, P _S ... Designation signal.

Claims (5)

[Claims] 1. An LED unit (4) integrally formed with two LED elements of red and green, an LED display panel (3) in which the LED units (4) are arranged in a matrix, and an LED display panel ( 3) An LED display device comprising a control means (7) for controlling the emission color and lighting of the LED unit, wherein the control means (7) displays the green LED unit based on a sensor signal detected by an illuminance sensor (5). An LED display device characterized by changing the emission color of (4). 2. The control means (7) comprises a comparing means (12) for comparing the sensor signal with a reference value, and the comparing means (1).
The color change means (13) for generating a color change signal based on the comparison signal from 2), and the color setting means (15) for changing the setting of the emission color by the color signal signal. The LED display device described. 3. An LED unit (4) integrally formed with two LED elements of red and green, an LED display panel (3) in which the LED units (4) are arranged in a matrix, and the LED display panel ( 3) In the LED display device provided with the control means (8) for controlling the emission color and lighting, the control means (8) controls the LED unit (4) based on the sensor signal detected by the illuminance sensor (5). An LED display device characterized in that the brightness is changed according to the color of light emitted. 4. The control means (8), a comparing means (21) for comparing the sensor signal with a reference value, and a brightness for generating a brightness signal corresponding to a deviation between the reference value and the sensor signal and weighted for each emission color. The LED display device according to claim 3, further comprising setting means (22). 5. The LED display device according to claim 1, wherein the illuminance sensor (5) is arranged on a display surface of the LED display panel (3).