JPH09283806A - Led display and display device using led display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve visibility by using first and second coloring agents having a visible-light transmittance lower than that of a third coloring agent and providing a third light emitting diode at a position where light blocking efficiency is higher than the positions of first and second light emitting diodes. SOLUTION: A blue (B) coloring agent has a visible-light transmittance higher than that of green (G) and red (R) coloring agents. When a blue light emitting diode is partially irradiated with light, it shows remarkable reflection effect. A print substrate, where a plurality of light emitting diodes 102 are provided and electrically connected, is placed in a resin case as a box 104 and sealed by filling agent 103. Each light emitting diode 102 is colored at its mold member in correspondence with light emitted from an LED chip. A light blocking member 101 is formed on the upper end surface of the resin case. By providing the light emitting diode having the coloring agent with a high visible-light transmittance and short-wave side light-emission wavelength on the light blocking member side, light emitting characteristic is maintained and gold color balance is obtained, thus, visibility can be improved.

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 having high luminous efficiency of a light emitting diode and excellent visibility, and a display device using the LED display device. The present invention relates to an LED display having excellent contrast even when the irradiation amount of the LED partially changes and a display device using the same.

[0002]

2. Description of the Related Art Today, with the development of silicon technology such as LSI and optical communication technology, it has become possible to process and transmit a large amount of information. Along with this, social demands for full-color and large-sized display devices capable of processing a large amount of image information are increasing more and more.

In particular, there is an extremely high demand for a large-sized display device that can be viewed by an unspecified number of people. As such a large-sized display device, there are known a multi-vision which displays a combination of many cold cathode tubes and a liquid crystal projector which uses a liquid crystal filter. However, the above-mentioned method has a large device weight and a large device volume. Moreover, since a high voltage is used for driving, maintenance and inspection is difficult. Alternatively, there is a problem that the usage environment is limited. For this reason, large-scale display devices have not come into widespread use.

On the other hand, recently, a light emitting diode (hereinafter, also referred to as an LED) using a solid-state light emitting device capable of emitting RGB (red, green, blue) three primary colors with high brightness has been developed.
With the development of the LED, the LED is suddenly attracting attention as a large display device and the like. A display device using an LED can have an extremely small device volume and device weight as compared with a conventional display device and can have a long life. In addition, it is relatively easy to manufacture as compared with a display using a conventional cold cathode fluorescent lamp, and has a very low driving voltage and power consumption, and thus is regarded as a promising large-sized display device.

A full-color display can be achieved by arranging such light-emitting diodes in a combination of RGB and arranging them in a matrix form and combining the respective emission colors. Specifically, when all the LEDs corresponding to RGB as one picture element are turned on, it becomes white, red and green become yellow, and green and blue become cyan. Furthermore, the brightness of each LED can be adjusted to produce various emission colors. A plurality of RGB light emitting diodes are arranged in a matrix on a substrate on which a conductive pattern is printed. The LED display is constructed by arranging the light emitting diode arranged on this substrate in a housing and protecting the space between the light emitting diode and the housing with a filling material. A hood is integrally formed with a casing made of epoxy resin as a light shielding member to prevent intrusion of direct sunlight and improve visibility. The light emitting diode is a semiconductor light emitting element L
The ED chip is arranged on the tip of the lead terminal and electrically connected to the lead terminal and the like. Epoxy resin or the like is used as a molding member for protecting the LED chip. In order to improve the light emission characteristics of such a mold member, the mold member is colored for each of the RGB light emitting diodes to give a filter effect.

[0006]

However, when the above-mentioned LED display is irradiated with sunlight or the like, even if a light-shielding member is provided, the light-shielding member is provided with a certain length or more in order to ensure visibility. The thickness and angle cannot be set. Therefore, external light cannot be uniformly blocked by the light blocking member. In particular, the LED display is often fixed once installed at a desired position and is not moved according to the irradiation light. When the LED display is fixedly installed,
Not only can the sunlight move for one day, but it can not cope with the change in the irradiation angle depending on the season.

LED in which RGB light emitting diodes are arranged
When the display is non-uniformly irradiated with light, the display color of the display surface of the LED display when the light is not emitted is different, which causes a problem that the contrast is lowered and the visibility due to the color unevenness is lowered. LE often used in bright places such as outdoors
Improving the contrast of the D display is an important issue. In particular, the LED display having the above-mentioned structure is not sufficient today, and further improvement in characteristics is required. In view of such problems, the present invention is to provide an LED display device having excellent visibility regardless of installation location, time, and the like.

[0008]

The invention of the present application is based on the first LE.
A first light emitting diode having a D chip and a mold member containing a first colorant that acts as a filter for the light emitted by the first LED chip, and the first LED chip emitted light. A mold member containing a second LED chip that emits a main emission wavelength shorter than the main emission wavelength of light and a second colorant that acts as a filter for the light emitted by the second LED chip. A second light emitting diode having a light emitting diode, a third LED chip that emits a main emission wavelength on a shorter wavelength side than a main emission wavelength of light emitted by the second LED chip, and the third LED chip emits light. A third light emitting diode having a mold member containing a third colorant that acts as a filter against the generated light, and the first and second colorants have a third color. Agent Remote visible light transmittance is small and,
LE in which the third light emitting diode is provided at a position having a higher light blocking ratio than the first and second light emitting diodes
It is a D display.

Further, the present invention provides a first light emitting device having a first LED chip and a mold member containing a first colorant which acts as a filter for the light emitted by the first LED chip. Diode and the first LED
A second LED chip that emits a main emission wavelength on a shorter wavelength side than a main emission wavelength of light emitted by the chip and the second LED
A second light emitting diode having a mold member containing a second colorant that acts as a filter for the light emitted by the chip, and a wavelength shorter than the main emission wavelength of the light emitted by the second LED chip. A third light emitting diode having a third LED chip that emits a main emission wavelength on the side and a mold member that contains a third colorant that acts as a filter for the light emitted by the third LED chip. Is disposed on a substrate, the substrate is covered with a casing having a light shielding member, and at least a part of the first, second and third light emitting diodes and the casing are filled with a filling material, The first and second colorants have a lower visible light transmittance than the third colorant, and the third light emitting diode is provided closer to the light shielding member than the first and second light emitting diodes. LED table It is a vessel.

Further, the light emitted from the first LED chip is in the range of 600 nm to 700 nm, and the light emitted from the second LED chip is from 495 nm to 56 nm.
LE in the range of 5 nm and the light emitted by the third LED chip in the range of 430 nm to 490 nm
The LED display according to claim 2, which is a D display, and the L
It is also a display device including a drive circuit electrically connected to the ED display.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of various kinds of experiments,
Based on this, it was found that the light emission characteristics, the visibility and the contrast due to the irradiation of external light in the LED display can be greatly improved by the visible light transmittance of the colorant contained in the mold member and the specific arrangement of the light emitting diodes. The present invention has been accomplished.

Although it is not clear why the characteristics of the present invention are improved by the configuration of the present invention, the visible light transmittance of the colorant in consideration of the color balance at the time of light emission of the LED under the partial light irradiation of the non-lighted LED display. It is considered that this is largely related to the color balance of the display. That is, a coloring agent such as a dye and / or a pigment is an LE having excellent emission characteristics such as emission efficiency and color purity when a light emitting diode is turned on for full color display.
Various determinations are made for each of the RGB light emitting diodes to be a D display. In the case of nighttime when there is no or little extraneous light illuminating the LED display, the change in the light transmittance of each of the RGB light emitting diodes does not cause any particular problem in using the LED display.

However, when the amount of light applied to the display surface of the LED display device is large and not uniform, the additive effect of the colors of the light-irradiated mold member and the light-unirradiated mold member causes the display surface to be in a non-light emitting state. Since the color is determined, a large discoloration occurs on the entire display surface. Specifically, L
In order to improve the light emitting characteristics of the ED display device, the blue colorant is made to have a higher visible light transmittance than green or red. When the blue light emitting diodes of the LED display in which the RGB light emitting diodes are arranged as described above are partially irradiated with light, the influence of reflection appears remarkably due to the light irradiation. In particular, when the LED chip is housed in the cup of the lead terminal, the light from the LED chip is affected by the colorant only once, but the external light reflected by the cup is twice affected by the colorant. It will be. For this reason, the entire display surface may appear reddish, bluish-white, or greenish-colored. On the other hand, when light is radiated to green, red or the like having low light transmittance and blue is not radiated, the additive color mixture of RGB appears blackish on the entire display surface. Therefore, it is considered that the contrast and the color balance change depending on the transmittance and the light blocking ratio (specific arrangement of the light emitting diodes).

When the partial change in the amount of light on the display surface is direct sunlight, it can be blocked to some extent by a light blocking member. However, the light-shielding member cannot be set to have a length, thickness, and angle greater than a certain amount in order to ensure visibility, and the light-shielding member cannot uniformly shield all from external light. In particular, the LED indicator is fixed once installed at a desired position and is not moved according to the irradiation light, so that it cannot cope with not only the movement of sunlight for one day but also the change of the irradiation angle due to the season.

In view of this, the present invention provides an LED display having excellent color balance while maintaining the light emission characteristics by arranging the LED having a high light transmittance of the colorant at a position where the influence of external light is smaller. Is. Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic plan view of various LED displays of the present invention, and FIG. 1A shows one pixel using R (red) G (green) B (blue) light emitting diodes one by one. It is a thing. FIG. 1B shows one L
In the ED display, four pixel elements are formed by using two light shielding members and four RGB light emitting diodes, respectively. In FIG. 1C, light emitting diodes of RG are arranged diagonally with respect to B, and one B is used for two RGs to form one pixel. FIG. 3 is an LE used in the present invention.
It is a schematic sectional drawing of a D display device. In the resin case, which is the housing 104, a plurality of light emitting diodes 102 each having a molded member colored according to the light emitted from the LED chip are arranged and a printed circuit board electrically connected to each other is filled with a filler 103 such as a silicon resin. It is enclosed in. A light shielding member 101 is formed on the upper end surface of the resin case. Each component of the present invention will be described below.

(Light-shielding member 101) The light-shielding member 101 is used to prevent the light-emitting diode 102 from becoming difficult to be visually recognized by the irradiation of external light. Therefore, the length, thickness, and angle of the light blocking member are determined in consideration of the installation location and the set viewing distance. It is preferable that the angle of the light shielding member can be changed according to the viewing distance. The installation angle of the light blocking member 101 with respect to the housing 104 can be selected as desired depending on the viewing distance, the installation angle of the housing, and the like, but is preferably 0 degrees to 10 with respect to the vertical direction of the display surface. Further, the light blocking member 101 may be colored in black or the like for the purpose of improving the light blocking efficiency.

The shading of the LED display varies depending on the installation angle of the LED display, the length and thickness of the shading member, the angle of the shading member with respect to the housing, and the like. Considering the usage environment, the LED display should be tilted from 0 to 10 degrees with respect to the ground plane and grounded, or the length of the light shielding member should be increased so that sunlight rays of 30 to 45 degrees are not directly irradiated. Arrange them to improve the contrast. When the partial change in the amount of light on the display surface is direct sunlight, it can be blocked to some extent by the light blocking member 101. However, the light-shielding member 101 cannot be set to have a length, thickness, and angle greater than a certain amount in order to ensure visibility, and the light-shielding member cannot uniformly shield all from external light. That is, in order to improve the contrast, the angle, length, thickness of the light-shielding member, the installation angle of the LED display, and the like have to be designed according to the visual recognition position and the distance, which reduces the degree of freedom. In particular, the LED indicator is fixed once installed at a desired position and does not move according to the irradiation light. Even if the above-mentioned angle is set, not only the movement of sunlight for one day but also the change of the irradiation angle depending on the season. It is not possible to cope with such. Therefore, there is a case where the contrast deviates from the set value and the contrast significantly decreases. Therefore, the present invention works particularly effectively.

In the present invention, the light emitting diode having a high visible light transmittance of the colorant and having a short emission wavelength is provided closer to the light shielding member than the light emitting diode having a low visible light transmittance and having a long emission wavelength. . Even in this case, it is difficult to uniformly block all the irradiation light, but in the vicinity of the time period when the sun sets on the horizon, etc., the probability that the LED display will be irradiated is high, but the light power of the sun is weak. In some cases, the contrast is not so affected. Therefore, if the incident angle of sunlight is in the range of 0 ° to about 26 ° horizontally, and more preferably 0 ° to about 15 ° horizontally, it is not necessary to consider the shielding of incident light relatively. Member 1
It is preferable to dispose a short wavelength light emitting diode having a high visible light transmittance at a position shielded by 01 or the like.

(Light-Emitting Diode 102) As the light-emitting diode 102 used in the present invention, a light-emitting element formed by molding an LED chip 203 using various kinds of semiconductors with a resin colored corresponding to each emission color is used. Specifically, GaA is formed on the substrate by liquid phase epitaxy or MOCVD.
1N, ZnS, ZnSe, SiC, GaP, GaAlA
s, AlInGaP, InGaN, GaN, AlInG
A material in which a semiconductor such as aN is formed as a light emitting layer is used. Examples of the semiconductor structure include a homo structure, a hetero structure, and a double hetero structure having a MIS junction and a PN junction. The emission wavelength can be selected from ultraviolet light to infrared light depending on the material of the semiconductor layer and its degree of mixed crystal. Furthermore, in order to have a quantum effect, the light emitting layer may have a single quantum well structure or a multiple quantum well structure. When an LED display is used in a place where external light is relatively strong, such as outdoors, it is preferable to use gallium nitride-based compound semiconductors for green and blue, and for red, gallium, aluminum, arsenic-based semiconductors and aluminum. It is preferable to use an indium, gallium, or phosphorus-based semiconductor. A light emitting diode can be formed by electrically connecting the LED chip 203 having such a semiconductor to the lead terminal 204 and the like by an electrical connecting member 202 such as a gold wire or an aluminum wire and covering it with the molding member 201. In addition, the LED chip 20 on the substrate
3 may be fixed with a conductive paste or the like, and after electrically connecting, a mold member may be covered to form a light emitting diode. In addition, LED as a full-color display
In order to utilize, the red emission wavelength is from 600 nm to 7
00nm, green 495nm to 565nm, and blue emission wavelength 430nm to 490nm
It is preferable to use the ED chip 203.

The respective light emitting diodes 102 are arranged on the substrate in a desired shape such as a matrix shape, a dotted shape, or a discontinuous arrangement of the light emitting diodes for improving the visibility from the left and right or the top and bottom as shown in FIG. Connect electrically. As shown in FIG. 1, when the LEDs are combined and arranged so as to form RGB picture elements as viewed from the respective light emitting diodes 102, the color mixing property can be increased and the light emission efficiency can be improved with a smaller number of LEDs. The substrate on which the light emitting diodes are arranged may be used not only for the arrangement of the light emitting diodes but also for the substrate for the driving circuit. The substrate is preferably one having high mechanical strength and low thermal deformation. Specifically, a substrate using ceramics, glass, or the like on which a conductor such as a copper foil is formed can be suitably used. Since the surface of the substrate on which the light emitting diodes are mounted coincides with the display surface of the LED display, it is preferable that the surface be colored dark brown or black to improve the contrast. In addition, unevenness may be applied to improve the adhesion to the filler.

(Filler 103) As the filler 103,
It is required that the light emitting diode 102, the housing 104, the substrate on which the light emitting diode is arranged, the light shielding member 101, and the like have good adhesion. In addition, the light emitting diode 102
Mechanical strength and weather resistance are required to protect the electric circuit connected to the. Specific examples of the filler 102 include epoxy resin, urethane resin, and silicone resin. Further, the filler 102 is provided on the display surface side of the LED display device. Therefore, a dye and / or a pigment such as dark brown or black may be contained in the filler for the purpose of improving the contrast. Further, a heat conductive member may be included in the filler for the purpose of radiating heat from the light emitting diode 102. Since the heat conducting member is also arranged between the light emitting diodes 102, it is required not to conduct electricity. Specific examples thereof include copper oxide and silver oxide.

(Case 104) The case 104 used in the invention of the present application is one that mechanically protects each light emitting diode 102 arranged in a desired shape such as a matrix on a substrate from the outside and has a desired shape. It can be formed in various sizes and shapes. Therefore, one picture element may be constituted by one housing or a large number of picture elements may be constituted. The housing may be integrally formed with the light shielding member 101 for reducing the influence of external light applied to the light emitting diode, or the light shielding member 101 and the housing 104 may be separately formed from the viewpoint of workability. After installing the housing 104, the light blocking member 10
1 may be combined to improve productivity. Further, the angle of the light blocking member 101 can be changed variously to improve the visibility. Further, the light-shielding member 101 is made of a material different from that of the housing 104, for example, the light-shielding member is made of a metal having high thermal conductivity such as aluminum or copper, and the housing is made of a polycarbonate resin or the like to improve the heat dissipation of the light-emitting diode and stabilize the light-emitting characteristics. It can also be turned into.

Since the housing 104 is affected by heat from the light emitting diode 102 and the like, it is preferable that the housing 104 has a small coefficient of thermal expansion in consideration of the adhesiveness with the filler 103. The inner surface of the housing 104 can be embossed to increase the adhesion area, or plasma-treated to improve the adhesion to the filler 103. In addition, it is desirable to use a material that is easy to mold because it is formed into a desired shape. Such a case 1
Specifically, as the material of 04, polycarbonate resin,
ABS resin, epoxy resin, phenol resin and the like are preferable.

(Molding Member 201) The molding member 201 used in the present invention is provided to protect the LED chips 203 and the metal wires for electrical connection thereof from external force and moisture. Further, the resin mold may contain a diffusing agent together with the colorant used in the present invention. This can reduce the directivity from the LED chip 203 and increase the viewing angle. In addition, the resin mold can be made into a desired shape by using LE
A lens effect of converging or diffusing the light emitted by the D chip 203 can be provided. Therefore, the resin mold may have a laminated structure. In particular,
It has a cat's eye shape, a convex lens shape, a concave lens shape, or a combination thereof. The mold member 201
As the material of (1), a transparent resin having excellent weather resistance such as epoxy resin and urea resin is preferably used. As the diffusing agent, barium titanate, titanium oxide, aluminum oxide, silicon oxide and the like are preferably used.

The colorant used in the present invention is to have a filter effect for improving the light emission characteristics by cutting out an unwanted wavelength of the light emitted by the LED chip 203 contained in the mold member. . Therefore, various dyes and pigments are variously selected according to the emission color of the light emitting diode 102 (main emission wavelength which is the main peak of emitted light). Further, the colorant may be dispersed and formed at various ratios in the mold member as desired. That is, the content concentration can be increased or decreased as it approaches the LED chip 203, and various selections can be made.

To mix the colorant into the mold member, after mixing and stirring the colorant in the raw material of the mold member 201, the colorant is put into a mold that can be formed into a desired mold member shape such as a shell shape and is cured together with an LED chip or the like. Can be formed by

The visible light transmittance of the present invention is the average transmittance of the transmission spectrum of the colorant in the visible light band. The visible light transmittance changes depending on the colorant contained in the mold member and its content.

(Driving Device 301) The driving device 301 used in the present invention is a device that has a lighting circuit and the like and is electrically connected to the LED display of the present invention in which a plurality of light emitting diodes 102 are arranged. Specifically, an LED display arranged in a matrix or the like is driven by an output pulse from a driving circuit. As the drive circuit, a RAM (Ran) that temporarily stores input display data is used.
Dom, Access, Memory), and a gradation control circuit that calculates a gradation signal for lighting the light emitting diode to a predetermined brightness from the data stored in the RAM.
A driver for switching on the output signal of the gradation control circuit to turn on the light emitting diode 102 is provided. The gradation control circuit calculates the lighting time of the light emitting diode 102 from the data stored in the RAM and outputs a pulse signal. A gradation signal which is a pulse signal output from the gradation control circuit is input to the driver of the light emitting diode 102 to switch the driver. The light emitting diode is turned on when the driver is turned on, and is turned off when the driver is turned off. Hereinafter, specific examples of the present invention will be described, but it goes without saying that the present invention is not limited to these.

[Embodiment 1] Each LED chip is formed as a light emitting element capable of emitting RGB light. Specifically, P-type Ga is used as an LED chip capable of emitting R (red) light.
After forming P-type and N-type GaAlAs on the As substrate using the temperature difference liquid crystal growth method, an electrode was formed and 660 nm was formed.
An LED chip having an emission wavelength of was formed. on the other hand,
As an LED chip capable of emitting G (green) light, a Si-doped InGaN is formed on a sapphire substrate by MOCVD.
Is formed as a semiconductor light emitting layer, and then an electrode is formed.
An LED chip having an emission wavelength of 5 nm was formed.
Similarly, as an LED chip capable of emitting B (blue), Si-doped InGaN having a different Si content was formed as a semiconductor light emitting layer on a sapphire substrate by using a MOCVD method, and then an electrode was formed to form an electrode having a thickness of 470 nm. An LED chip having an emission wavelength was formed. These LED chips were electrically connected by wire bonding using respective lead frames and gold wires.

Next, these LED chips are inserted and fixed into the casting case for each LED chip, and epoxy resins mixed and stirred while changing the contents of the colorants of R, G and B are poured into the casting case and cured. After that, it was taken out to form a light emitting diode. The molding resin of the light emitting diode is formed in an elliptical shape when viewed from the front in consideration of color mixing from the left and right or from the top and bottom.
The average of visible light transmittance of each RGB is R = 44%, G
= 35% and B = 71%.

The respective light emitting diodes of the RGB light emitting diodes are arranged close to each other so as to enhance the color mixing property, and the light emitting diodes are arranged on the printed circuit board at the positions of the vertices of the equilateral triangle as shown in FIG. 1 (A). A printed circuit board on which a light emitting diode was arranged was inserted and fixed inside a housing integrated with a light shielding member made of epoxy resin. Next, in order to improve the weather resistance, silicone rubber was filled inside the casing excluding the light emitting tip of the light emitting diode and cured at 120 ° C. for 5 hours to form an LED display. The LED display was electrically connected to a drive circuit to form the LED display device shown in FIG.

The LED display device, the light emitting light source 401 and the optical measuring device 402 are arranged as shown in FIG. 4, and the halogen lamp (200 W) which is the light emitting light source 401 is LE from a distance of 10 m.
While illuminating the D display device and moving the halogen lamp, the chromaticity, brightness, and contrast were measured with an optical measuring device (BM-7 manufactured by TOPUKON). 90 degree angle, that is, L
The average value of the LED display device when the light from the light emitting source 401 is vertically incident on the ED display device is the xy chromaticity diagram (Ke).
ll Chart) when white (x = 0.31, y
= 0.31) and the power consumption were measured.

The power consumption at this time was about 20 W.
When the LED display is turned off and the same measurement is performed, a *
In the b * macro diagram (a * = 0.3, b * = 0.3,
c * = 200 cd / m ² ). Next, set the emission light source to 0
It was gradually moved from 90 degrees to 90 degrees. Up to a moving angle of 45 degrees, all of the light emitting diodes were shaded by the light shielding member and looked black. Further, it had almost the same chromaticity up to a moving angle of about 70 degrees. Only when the light-emitting diode of B having a movement angle of more than 73 degrees was irradiated with light, the contrast decreased and the chromaticity changed significantly.

[Comparative Example 1] The same procedure as in Example 1 was carried out except that the substrate having the light emitting diode and the casing having the light shielding member were attached in the opposite manner to Example 1 except that the side closer to the light shielding member was set to R and G. An LED indicator and an LED display device were formed. This LED display device was measured in the same manner as in Example 1. The power consumption during light emission was the same as in Example 1. Up to a movement angle of 45 degrees, the shading member formed a shade and had the same chromaticity as in Example 1, but when it exceeded 45 degrees and the light emitting diode of B was irradiated with light, it looked bluish. Compared to the same angle of 1, the contrast was reduced by about 17%.

From the above results, according to the present invention, it is possible to provide an LED display device which has an excellent contrast by significantly reducing the deterioration of visibility due to the movement of external light while maintaining the light emission characteristics, as compared with the comparative example.

[0036]

The LED display device and the display device using the same according to the present invention can provide an LED display device excellent in color balance and a display device using the same while maintaining the light emission characteristics. Specifically, by adopting the constitution of claim 1 of the present invention, while maintaining characteristics such as light emission efficiency and color balance at the time of light emission of the LED display, it is possible to improve contrast even at the time of partial irradiation of light. L with excellent visibility
It can be an ED display. In particular, it is possible to improve the contrast while preventing the viewing angle from being narrowed by the light shielding member.

With the configuration of claim 2 of the present invention, while maintaining the characteristics such as the luminous efficiency and the color balance when the LED display emits light, the contrast and the like can be improved even when the external light is partially irradiated such as outdoors. LED with excellent visibility
It can be an indicator. In particular, it is possible to improve the contrast while preventing the viewing angle from being narrowed by the light shielding member.

With the configuration of claim 3 of the present invention, it is possible to provide a full-color LED display which is excellent in visibility such as contrast while maintaining the light emission efficiency and characteristics of the light emitting diode even when irradiated with external light.

With the structure according to claim 4 of the present invention, it is possible to provide an LED display device excellent in visibility such as contrast while maintaining the light emission efficiency and light emission characteristics of the light emitting diode.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an LED display device of the present invention.

FIG. 2 is a schematic sectional view of a light emitting diode used in the present invention.

FIG. 3 is a schematic perspective view of an LED display device of the present invention.

FIG. 4 is a schematic cross-sectional view showing a measuring method for measuring contrast according to a specific arrangement of light emitting diodes.

FIG. 5 is the visible light transmittance of each of the RGB colorants used in the present invention.

[Explanation of symbols]

 101 ... Shading member 102 ... Light emitting diode 103 ... Filling material 104 ... Housing 201 ... Mold member containing colorant 202 ... Electrical connection member 203 ... LED chip 204 ... Lead terminal 301 ... Driving circuit 401 ... Light source 402 ... Optical measuring device

Claims (4)

[Claims] 1. A first LED chip and a first LED chip which acts as a filter for the light emitted by the first LED chip.
And a second LED chip that emits a main light emission wavelength on a shorter wavelength side than the main light emission wavelength of the light emitted by the first LED chip. And a second light emitting diode having a mold member containing a second colorant that acts as a filter for the light emitted by the second LED chip,
A third LED chip emitting a main emission wavelength on a shorter wavelength side than a main emission wavelength of the light emitted by the second LED chip and a third LED chip acting as a filter for the light emitted by the third LED chip. A third light emitting diode having a mold member containing the colorant of No. 3, and the first and second colorants have a visible light transmittance lower than that of the third colorant. Further, the LED display is characterized in that the third light emitting diode is provided at a position having a higher light blocking rate than the first and second light emitting diodes. 2. A first LED chip and a first LED chip which acts as a filter for the light emitted from the first LED chip.
And a second LED chip that emits a main light emission wavelength on a shorter wavelength side than the main light emission wavelength of the light emitted by the first LED chip. And a second light emitting diode having a mold member containing a second colorant that acts as a filter for the light emitted by the second LED chip,
A third LED chip emitting a main emission wavelength on a shorter wavelength side than a main emission wavelength of the light emitted by the second LED chip and a third LED chip acting as a filter for the light emitted by the third LED chip. A third light emitting diode having a mold member containing the colorant of
The substrate is covered with a casing having a light shielding member, and at least a part of the first, second and third light emitting diodes and the casing are filled with a filler, and the first and second colorants are provided. Has less visible light transmittance than the third colorant, and
An LED display, wherein the third light emitting diode is provided closer to the light shielding member than the first and second light emitting diodes. 3. The light emitted from the first LED chip is 6
In the range of 00 nm to 700 nm, and the second L
The LED display according to claim 2, wherein the light emitted by the ED chip is in the range of 495 nm to 565 nm, and the light emitted by the third LED chip is in the range of 430 nm to 490 nm. 4. The LED display according to claim 2, and the LED.
A display device, comprising: a driving circuit electrically connected to the display.