TWI425458B - Led display device - Google Patents

Description

LED display device

The present invention relates to an LED display device.

A Light Emitting Diode (LED) is a semiconductor component that converts current into light of a specific wavelength range. The light-emitting diode is widely used in the field of illumination because of its high brightness, low operating voltage, low power consumption, easy matching with integrated circuits, simple driving, and long life.

Light-emitting diodes have gradually replaced cold cathode fluorescent lamps as light sources for various display panels due to their advantages of good light quality, small size, environmental protection and high luminous efficiency. A typical display kanban usually consists of a light source and a transparent light guide plate, and the light source is usually disposed on the side of the light guide plate. A defect is formed on the light-emitting surface of the light guide plate to destroy the total reflection of the light on the light guide plate, so that the light emitted by the light source is emitted from the defect portion. The above defects constitute a number of patterns to constitute the content to be displayed. However, in such an advertising panel, since it is necessary to fabricate a microstructure on the light guide plate, it is difficult to manufacture. Moreover, the color of the pattern displayed by the advertisement billboard is the same as the color of the light source, and the display effect is relatively simple.

In view of this, it is necessary to provide an LED display device having a rich display color.

An LED display device includes a light source and a light guide plate. The light guide plate has a light incident surface and a light exit surface. The light source is disposed adjacent to the light incident surface, and the light emitted by the light source is from the light guide plate The light incident surface is incident and exits from the light exit surface of the light guide plate. The light-emitting surface of the light guide plate is provided with a pattern coated with the first phosphor powder and a pattern coated with the second phosphor powder. The color of the light emitted by the first phosphor after being excited by the light source is different from the color of the light emitted by the second phosphor after being excited by the light source.

A pattern coated with the first phosphor powder and a pattern coated with the second phosphor powder are provided on the light-emitting surface of the light guide plate. Since the color of the light emitted by the first phosphor after being excited by the light source is different from the color of the light emitted by the second phosphor after being excited by the light source, the color displayed by the display device is relatively rich.

The invention will now be further described with reference to the specific embodiments thereof with reference to the accompanying drawings.

100,200‧‧‧LED display device

110, 210‧‧‧ Light source

211‧‧‧first light source

212‧‧‧Second light source

113, 213‧‧‧ substrate

120, 220‧‧‧Light guide plate

121, 221‧‧‧ into the glossy surface

122, 222‧‧‧ shine surface

130, 230‧‧‧ first fluorescent powder

140, 240‧‧‧second phosphor powder

150‧‧‧ Third Fluorescent Powder

1 is a schematic structural view of an LED display device in a first embodiment of the present invention.

2 is a schematic structural view of an LED display device in a second embodiment of the present invention.

As shown in FIG. 1 , an LED display device 100 includes a light source 110 and a light guide plate 120 .

The light source 110 is a light emitting diode or a laser diode. The light emitting diodes are arranged in an array shape and are disposed on a surface of a substrate 113. The light source 110 provides corresponding illumination light to the display device.

The light guide plate 120 is made of a transparent material, and the material thereof includes polymethyl methacrylate (PMMA), polycarbonate (PC), glass, epoxy, and the like. The light guide plate 120 has a light incident surface 121 and a light exit surface 122. The light source 110 is disposed adjacent to the light incident surface 121. The light emitted by the light source 110 is incident from the light incident surface 121 of the light guide plate 120, and then emitted from the light exit surface 122 of the light guide plate 120. The light guide plate 120 is coated with a letter pattern A composed of the first phosphor powder 130 and a second firefly The letter pattern B composed of the light powder 140. The first phosphor powder 130 is excited by the light emitted by the light source 110 to emit light of a first color, and the second phosphor powder 140 is excited by the light emitted by the light source 110 to emit light of a second color.

In this embodiment, the light source 110 is a blue light emitting diode that emits light in a wavelength range of 435 nm to 475 nm. Correspondingly, the first phosphor powder 130 is a green phosphor powder that is excited by the blue light emitted by the light source 110 to emit light in a wavelength range of green light. The second phosphor powder 140 is a red phosphor powder that is excited by the blue light emitted by the light source 110 to emit light in a red wavelength range. When the light source 110 is turned on, the first phosphor powder 130 will emit green light to form a green letter A, and the second phosphor powder 140 will emit red light to form a red letter B. It can be seen that in the LED display device 100 described above, since different patterns can be displayed by using different colors, the display color is richer and the display effect is better. In addition, since the first phosphor powder 130 and the second phosphor powder 140 are formed on the light-emitting surface of the light guide plate 120 by a coating method. The first phosphor powder 130 and the second phosphor powder 140 can be effectively removed according to the needs of the display content, and at the same time, the phosphor powder is coated into a new pattern to meet the needs of display. The display content may be Chinese characters, letters or any combination thereof, or may be a pattern, or a combination of a pattern and any character.

If necessary, an opaque substance is coated on the areas other than the coating areas of the first phosphor powder 130 and the second phosphor powder 140, and the opaque substance may be used in addition to the first phosphor powder 130 and the second phosphor powder 140. The light emitted from the area is shielded so as not to affect the pattern displayed by the first phosphor powder 130 and the second phosphor powder 140.

The light source 110 may also be a light-emitting diode that emits purple light or ultraviolet light, and has a light-emitting wavelength of less than 400 nm. The first phosphor powder 130 is excited by purple light or ultraviolet light to emit green light to form a green letter A, and the second phosphor powder 140 is subjected to The purple light or ultraviolet light excites and emits red light to form a red letter B.

In the LED display device 100 described above, the light-emitting surface of the light guide plate 120 further includes a letter pattern C composed of the third phosphor powder 150. The third phosphor 15 is a yellow phosphor that is excited by the blue light emitted by the light source 110 to emit light in a yellow wavelength range. When the light source 110 is turned on, a yellow letter C will also be displayed on the light guide plate.

In the above embodiment, the first phosphor powder and the second phosphor powder are excited by light of the same wavelength to emit light. In fact, the first phosphor and the second phosphor may also be excited by light in different wavelength ranges to emit light.

Referring to FIG. 2 , a second embodiment of the present invention provides an LED display device 200 . The LED display device 200 includes a light source 210 and a light guide plate 220 .

The light source 210 includes a first type of light source 211 and a second type of light source 212. The first light source 211 and the second light source 212 are spaced apart from each other on the substrate 213. The wavelength of the light emitted by the first light source 211 is smaller than the wavelength of the light emitted by the second light source 212. In this embodiment, the first light source 211 and the second light source 212 are light emitting diodes or laser diodes, and the two are staggered to form an array shape. The first type of light source 211 emits light in a blue wavelength range having an emission wavelength of 435 nm to 475 nm. The second source 212 emits light in the green wavelength range with an emission wavelength of 500 nm to 560 nm. The opening and closing of the first light source 211 and the second light source 212 can be separately controlled, so that the first light source 211 and the second light source 212 can be separately turned on or turned on separately.

The light guide plate 220 has a light incident surface 221 and a light exit surface 222. The light source 210 is disposed adjacent to the light incident surface 221, and the light emitted by the light source 210 is incident on the light from the light guide plate 220. The face 221 is incident and then exits from the light exit face 222 of the light guide plate 220. The light guide plate 220 is coated with a letter pattern A composed of the first phosphor powder 230 and a letter pattern B composed of the second phosphor powder 240. Different from the first embodiment, the first phosphor powder 230 is excited by the light emitted by the first light source 211 to emit light of the first color. The second phosphor 240 is excited by the light emitted by the second source 212 to emit light of a second color.

In the embodiment, the first phosphor powder 230 is a green phosphor, which is excited by the blue light emitted by the first light source 211 to emit light in a green wavelength range. The second phosphor powder 240 is a red phosphor powder, which is excited by the blue light emitted by the first light source 211 to emit red light, and is also excited by the green light emitted by the second light source 212. And it glows red. When only the first type of light source 211 is turned on, both the first phosphor powder 230 and the second phosphor powder 240 are excited by blue light to emit light. Wherein, the first phosphor powder 230 will emit green light to form a green letter pattern A, and the second phosphor powder 240 will emit red light to form a red letter pattern B. When only the second light source 212 is turned on, since the second light source 212 emits green light, the first phosphor powder 230 is not excited by the second light source 212. The second phosphor 240 will be excited by the green light emitted by the second source 212 to emit red light. At this time, on the LED display device 200, only one red letter pattern B is displayed. It can be seen that different modes can be displayed on the LED display device 200 by controlling the opening and closing of the first light source 211 and the second light source 212, respectively. The LED display device 200 of the present embodiment also has an effect of displaying rich colors. At the same time, the first phosphor powder 230 and the second phosphor powder 240 are formed on the light-emitting surface of the light guide plate 220 by a coating method. The first phosphor powder 230 and the second phosphor powder 240 can be effectively removed according to the needs of the display content, and at the same time, the phosphor powder is coated into a new pattern to meet the needs of display. The display content may be Chinese characters, letters or Any combination may also be a pattern, or a combination of a pattern and any character.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

100‧‧‧LED display device

110‧‧‧Light source

113‧‧‧Substrate

120‧‧‧Light guide

121‧‧‧Into the glossy surface

122‧‧‧Glossy surface

130‧‧‧First Fluorescent Powder

140‧‧‧Second Fluorescent Powder

150‧‧‧ Third Fluorescent Powder

Claims (6)

An LED display device includes a light source and a light guide plate. The light guide plate has a light incident surface and a light exit surface. The light source is disposed adjacent to the light incident surface, and the light emitted by the light source is incident from the light incident surface of the light guide plate and is emitted from the light guide plate. The surface of the light guide plate is provided with a pattern coated with the first phosphor powder and a pattern coated with the second phosphor powder, and the first phosphor powder is excited by the light source. The color of the light emitted later is different from the color of the light emitted by the second phosphor after being excited by the light source. The LED display device of claim 1, wherein the light source is a light emitting diode or a laser diode. The LED display device of claim 1, wherein the light source comprises a first light source and a second light source, wherein the first light source has an emission wavelength within a wavelength range of the first wavelength light. The second light source has an emission wavelength that is within a wavelength range of the second wavelength light, the first phosphor is excited by light in a first wavelength range, and the second phosphor is exposed to a second wavelength range. The light is excited to emit light, the first wavelength is the same as the value of the second wavelength, and the wavelengths of the first wavelength and the second wavelength are in the range of 435 nm to 475 nm. The LED display device of claim 1, wherein the light source comprises a first light source and a second light source, wherein the first light source has an emission wavelength within a wavelength range of the first wavelength light. The second light source has an emission wavelength that is within a wavelength range of the second wavelength light, the first phosphor is excited by light in a first wavelength range, and the second phosphor is exposed to a second wavelength range. The light is excited to emit light, the first wavelength is the same as the value of the second wavelength, and the wavelength of the first wavelength light and the second wavelength light is less than 400 nm. The LED display device of claim 1, wherein the light source comprises the first type a light source having a light emitting wavelength in a wavelength range of the first wavelength light, and a second light source having a light emitting wavelength in a wavelength range of the second wavelength light, the first light emitting The light powder is excited by the light in the first wavelength range, and the second fluorescent powder is excited by the light in the second wavelength range, wherein the first wavelength is smaller than the second wavelength, and the light of the first wavelength The wavelength range is from 435 nm to 475 nm, and the wavelength of the second wavelength of light ranges from 500 nm to 560 nm. The LED display device of claim 1, wherein the first light source and the second light source are respectively turned on and off to control the LED display device to display different patterns.