JP2010107819A - Led display device and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED display device and lighting system for correcting difference in light intensity and illuminance due to the difference in angle from the LED front plane. <P>SOLUTION: The LED display device capable of displaying a character message using an LED, or the LED lighting system using the LED for illumination is provided. By combining the LEDs having different light distribution characteristic, the visibility of the display characters from a further large range is improved or the illuminance in a further large space is improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an LED display device and an illumination device that correct a difference in luminous intensity and illuminance due to a difference in angle from the front of the LED.

  The brightness of each LED is expressed in terms of luminous intensity. In general, the luminous intensity is highest near the front of the LED, and the luminous intensity decreases as the angle from the front increases. The absolute value of the luminous intensity and the attenuation due to the angle from the front are different for each LED.

  For example, when an LED display device is used for an outdoor signboard, an LED having a high luminous intensity is used to improve visibility even from a distance. However, the light intensity of the LED having such a high luminous intensity is drastically decreased except for the front surface. In other words, it has a narrow light distribution characteristic.

  On the other hand, there is an LED having a wide light distribution characteristic that is not as luminous as the above-described LED, but has a small decrease in luminous intensity other than the front.

  In general, outdoor signage is installed at high places. The front of the signboard, that is, the front of the LED is installed facing away so that it can be seen from a distance. Then, the closer to the sign, the farther from the front of the LED. For this reason, when an LED having a high luminous intensity is used, there is a problem in visibility from a position close to the signboard because the light distribution characteristic is narrow.

  In order to solve this problem, a method has been proposed in which a plurality of LEDs having different mounting angles are accommodated in one display unit, so that the luminous intensity when viewed from a distance is maintained and the luminous intensity does not decrease even in the vicinity. However, in this method, LEDs having different mounting angles must be arranged side by side, which complicates the manufacturing process.

  Similarly, in the LED lighting device, the front illuminance is high only with the high-luminance LED, but the lateral illuminance is extremely attenuated.

In order to compensate for this drawback, there is a means of changing the mounting angle of the LED that irradiates the front and the LED that irradiates the side. However, in this method, a plurality of LED parts corresponding to different mounting angles must be manufactured, which leads to an increase in manufacturing cost.
Japanese Laid-Open Patent Publication No. 7-302931 (FIGS. 1, 2, and 4)

  As an outdoor signboard, it is desirable that visibility is high even when viewed from a remote place or a position close to the signboard. However, in reality, if importance is placed on the visibility when viewed from a distance, it becomes difficult to see when approaching the signboard, and if it is easy to see from the vicinity of the signboard, there is a problem in visibility from a distance. In addition, the currently proposed solution complicates the manufacturing process and leads to high costs.

  The present invention has been made to solve the above-described problems, and maintains high visibility even when viewed from a distance or near a signboard without increasing the manufacturing cost. .

  In general, when characters are displayed by LEDs, the LEDs are arranged on a matrix, and the characters are expressed in an on / off state by individual LEDs. At this time, one unit constituting the matrix is composed of one or more LEDs, and this is called a display unit. The type and number of LEDs constituting the display unit are usually determined by the number of display colors, the required luminous intensity, and cost.

  The LED display device according to claim 1 is an LED display device in which two or more LEDs of the same color are arranged to form one display unit and display characters and numbers, and LEDs having different light distribution characteristics are displayed as one display unit. As a result, the visibility can be improved with a wider field of view.

  In addition, the LED illumination device according to claim 2 improves the illuminance of the space in a wider range by combining a plurality of types of LEDs having different light distribution characteristics in the LED illumination device in which a plurality of LEDs of the same color are arranged. it can.

  According to the first aspect of the present invention, an LED having a high luminous intensity and a narrow light distribution characteristic maintains visibility from a distance from the front, and an LED having a wide light distribution characteristic covers the visibility at a position outside the front, so that it is close from a distance. Therefore, display with high visibility is possible without increasing the manufacturing cost.

  Further, according to the second aspect of the present invention, an illuminating device that has high illuminance on the front face and does not drop much illuminance even when the illuminance deviates from the front face can be achieved without increasing the manufacturing cost.

  Hereinafter, an LED display device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a display unit of an LED display device, FIG. 2 is a configuration diagram showing a configuration of one display unit, and FIG. 3 is an example of a general light distribution characteristic of an LED having a high luminous intensity. 4 is an example of a general light distribution characteristic of an LED having a low luminous intensity. FIG. 5 is an image diagram showing that the angle from the front of the signboard, that is, the LED changes according to the distance from the signboard, and FIG. It is one Embodiment of the LED lighting apparatus of this invention.

  First, the display unit of the LED display device will be described with reference to FIG. The display unit is generally composed of one or more LEDs. In order to display characters with LEDs, display units are arranged on a matrix, and characters are expressed by turning on / off each display unit. FIG. 1 shows an example in which the Chinese character “Den” is displayed in a matrix of 16 × 16. The black display unit is turned on and the white display unit is turned off.

  Next, the configuration of the display unit of the LED display device will be described with reference to FIG. In this figure, up to four LEDs can be arranged in one display unit, but the actual number of mounted LEDs is adjusted by the balance of luminous intensity. For example, in this example, two LEDs having high luminous intensity are arranged diagonally, and only one LED having a wide light distribution characteristic is arranged. The reason for making it diagonal is to make the appearance as seen from the top, bottom, left and right as uniform as possible.

  Next, with reference to FIG. 3 and FIG. 4, the difference in the light distribution characteristic of LED is demonstrated. FIG. 3 shows an example of the light distribution characteristic of an LED having a high luminous intensity. FIG. 4 is an example of the light distribution characteristic of an LED that is not as luminous as the LED of FIG. 3, and the way in which the luminous intensity falls when it is off the front is loose.

  Next, with reference to FIG. 5, it will be described that the angle from the front of the LED changes depending on the distance from the LED display device or the signboard with the LED display device. The LED display device or the signboard with the LED display device is installed on the wall surface or rooftop of the building. At that time, the LED display device or the entire signboard may be set slightly downward. In order to improve visibility from a distance, the front of the LED is directed to the distance. Therefore, the more the observer who can see the LED display device or signboard from the front moves in the direction closer to the LED display device or signboard, the deeper the angle from the front of the LED when viewing the LED display device or signboard. Become.

  Next, an embodiment of the LED lighting device of the present invention will be described with reference to FIG. The LED illumination device secures sufficient illumination capability by arranging a large number of LEDs in a planar shape. In the example of FIG. 6, among the LEDs arranged in a planar shape, an LED having a high luminous intensity is arranged in the central portion, and an LED having a wide light distribution characteristic is arranged in the side portion even though the luminous intensity is low. By doing so, the illuminance of the front of the LED lighting device is high, and the illuminance does not drop abruptly even if the LED illumination device deviates from the front.

  It can be used as an LED display device with high advertising power, or as an LED lighting device with high illumination ability to the periphery.

It is a figure which shows one display unit of an LED display apparatus. It is a front view which shows the structure of one display unit. It is an example of the light distribution characteristic of LED with a high luminous intensity. It is an example of the light distribution characteristic of LED with a low luminous intensity. It is an image figure which shows that the angle from a front changes with the distance from a LED display apparatus or a signboard. This is an example of an LED lighting device using two types of LEDs having different light distribution characteristics.

Explanation of symbols

1 Display unit 2 LED with high luminous intensity
3 LED with low luminous intensity
4 LED display devices or billboards with LED display devices 5 Buildings and other buildings

Claims (2)

  Visibility in a wide range by combining two or more LEDs of the same color as a single display unit and combining LEDs with different light distribution characteristics as a single display unit. LED display device, characterized in that can be improved.   An LED illumination device in which a plurality of LEDs of the same color are arranged, and the illuminance can be improved in a wide range by combining a plurality of types of LEDs having different light distribution characteristics.

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