JPH1124607A - Light emitting diode matrix display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a matrix display device in which the luminance can be increased without raising the power of a light emitting diode or increasing the number of light emitting diodes, and the contrast can be also increased. SOLUTION: A light emitting diode group having a plurality of intrinsic photoemission colors is arranged within each pixel area 2, and the pixel area 2 is partitioned by a barrier rib 13. A slope having an inclination as the lights emitted sideways by the light emitting diodes are reflected in the front direction is formed on the barrier rib 3. The slope is classified by color by painted surfaces 15r, 15g, 15b, 16r, 16g, 16b so as to have a reflecting characteristic of mainly reflecting the light having a wavelength corresponding to each emitting color of the light emitting diodes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode matrix display device in which a large number of chip type light emitting diode elements are arranged in a matrix, and a plurality of sets are surrounded by partition walls to form one unit of pixel.

[0002]

2. Description of the Related Art FIG. 5 shows an example of a conventional light-emitting diode matrix display device in which a large number of chip-type light-emitting diode elements are arranged in a matrix, and a plurality of groups are surrounded by partition walls to form one unit of pixel. FIG. In FIG. 5, reference numerals 1r, 1g, and 1b denote chip type light emitting diode elements. The light emitting wavelengths of the light emitting diode elements 1r, 1g, and 1b are not the same. For example, the light emitting diode element 1r has a light emitting color of red, the light emitting diode element 1g has a light emitting color of green, and the light emitting diode element 1b has a light emitting color of blue. Can be performed. Light emitting diode element 1r, 1
The three pixels g and 1b form one pixel region 2.

However, as it is, the light emitting diode elements 1r, 1g, 1b
Light enters the light emitting diode element of the adjacent pixel, where a phenomenon occurs in which the light is visually recognized as stray light due to irregular reflection or the like. This causes the resolution of an image displayed by the light emitting diode matrix display device to decrease, which is not desirable. Therefore, a partition wall 5 is provided at the boundary with the adjacent pixel region,
It is necessary to block this stray light.

FIG. 6 is a side sectional view of FIG. As shown in FIG. 6, the partition 5 is composed of the light emitting diode elements 1r, 1g, 1b.
And has a height slightly higher than the above, and is mounted on the printed wiring board 6. Light-emitting diode element 1
One of the terminals r, 1g, and 1b is mounted so as to be electrically connected to a part of a conductive line 7 formed of a copper foil or the like on the printed wiring board 6. Further, another conductive line 8 is provided on the other surface of the printed wiring board 6, and the light emitting diode element 1 is formed by a through hole (not shown).
r, 1g, and 1b are electrically connected to the other terminals.

If the conductive line 7 transmits a signal in the row direction, the other conductive line 8 transmits a signal in the column direction, and the ON signals of the lines in both directions overlap. The light emitting diode element at the selected location emits light.

FIG. 7 shows another conventional example, and shows a side sectional view of an improved configuration of FIG. In FIG. 6, the cross section of the partition 5 is provided vertically in FIG. 6, but in FIG. 7, the partition 9 is formed by a concave curved surface. By doing so, there is an advantage that the strength of the partition wall 9 is increased, and at the same time, the light utilization rate is increased by reflection of this portion.

[0007]

In the structure shown in FIG. 5, the area of the light emitting diode elements 1r, 1g and 1b which actually emit light is considerably smaller than the area of the square pixel region 2. Therefore, when displaying a large-area image that emits light over a large number of pixels, the roughness of the image is conspicuous, which is not desirable in terms of image quality. In order to solve this, the light emitting diode elements 1r, 1
It is conceivable to arrange g and 1b, but the manufacturing cost is significantly increased. Also, although the overall brightness increases,
Since the amount of heat generated per area also increases, it becomes difficult to take measures for heat dissipation.

The light emitting diode elements 1r, 1
In the device using g, 1b, as shown in FIG.
In addition to the light 10 emitted in the front direction, the light 11 emitted in the side direction also exists at a considerable rate. Most of the light 11 in the side direction cannot be visually recognized from the front, and is wasted. FIG. 7 is intended to solve this problem, and the side cross section of the partition 9 is formed as a concave curved surface as shown. Then, as a material of the partition wall 9, a material having a high reflectance is used, or the surface thereof is coated or plated with a substance which increases the reflectance.

Then, as shown by the light 12 in FIG. 7, the side light component wasted in FIG. 6 is radiated in the front direction, and the light utilization rate is increased. Brightness increases. In this case, there is no problem of heat radiation because there is no power rise. In FIG. 7, the cross-sectional shape of the partition wall 9 is drawn as a concave curved surface. However, if it is desired to completely reflect the light 12 in the front direction, the curved surface can emit light from the light emitting diode elements 1r, 1g, 1b as much as possible. It is desirable to approach a parabola centered on the center point. However, when the front luminance is not so required, the inclined surface may be formed as a flat surface instead of a curved surface as shown by a broken line in FIG. In this case, the light is scattered to the left and right, and the manufacture of the partition wall 9 is facilitated.

However, in the case of FIG. 7, there is a problem that not only the light from the side of the light emitting diode elements 1r, 1g and 1b but also the light from outside the front is reflected. That is, even when the light emitting diode elements 1r, 1g, and 1b are not lit, many parts of the pixel region 2 are illuminated by the external light, and accordingly, the difference in luminance from the lit state is reduced, and the Contrast is reduced.

Also, the light emitting diode elements 1r, 1g, 1
When performing full-color display using three colors of red, green, and blue as b, if there is an element having a low maximum luminance, the limit of the maximum luminance is determined accordingly. In particular, a green element often cannot provide sufficient luminance, and a green component requires more output than other red and blue components to obtain a correct white color.

Conventionally, to solve this,
For example, it has been practiced to increase the luminance by providing only two green elements in one pixel. However, this naturally increases costs. In addition, the area of one pixel is correspondingly large, which is not suitable for high-definition display.

The present invention has been made in view of such a problem, and can increase the luminance without increasing the power of the light emitting diode element or the number of light emitting diode elements, and can improve the contrast. An object is to provide a light emitting diode matrix display device that can be increased.

[0014]

According to the present invention, in order to solve the above-mentioned problems of the prior art, a plurality of light emitting diode elements having a plurality of unique luminescent colors are arranged in each pixel, In the light emitting diode matrix display device partitioned by a partition wall, in the partition wall, an inclined surface having an inclination to reflect light emitted in the side direction of the light emitting diode element in the front direction is formed, and the inclined surface is formed on the inclined surface. The present invention also provides a light emitting diode matrix display device having a reflection characteristic of mainly reflecting light having a wavelength corresponding to each emission color of the light emitting diode element.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a light emitting diode matrix display device according to the present invention will be described with reference to the accompanying drawings. 1 to 4 are perspective views showing first to fourth embodiments of a light emitting diode matrix display device according to the present invention, respectively.

In FIG. 1, a pixel region 2 forming one unit of pixel is partitioned by a partition 13. The pixel region 2 has a predetermined depth as in the related art, and the light emitting diode elements 1r, 1g,
1b is indicated by broken lines 14r, 14g, 14b at its bottom.
It is mounted at a certain position.

The light emitting diode elements 1r, 1 of the partition 13
The portion parallel to the arrangement direction of g and 1b is the top 2
3 is a slope inclined from the bottom to the bottom of the pixel region 2. Each of the inclined surfaces sandwiching the light emitting diode elements 1r, 1g, 1b is divided into three regions, and is colored according to the opposing light emitting diode elements 1r, 1g, 1b.

That is, the portions 15r and 16r facing the red light emitting diode element 1r are painted with the same system of red, and the portions 15r and 16r facing the green light emitting diode element 1g.
The portion of 16g has the same system of green paint, and the portion of 15b and 16b facing the blue light emitting diode element 1b has the same system of blue paint. The partition 1
The surface 17 orthogonal to the arrangement direction of the three light emitting diode elements 1r, 1g, 1b is not an inclined surface and is not colored.

In such a configuration, the light-emitting diode elements 1r, 1g, 1b are separated from the painted surfaces 15r to 15b, 16b.
The light emitted in the r to 16g directions is mainly reflected in the front direction, as in FIG. 7, so that the light utilization rate increases and the luminance increases. In addition, with respect to external light from the front, the painted surface absorbs light other than the specific colors and does not reflect the light. For example, with respect to the painted surfaces 15r and 16r, red wavelength light is reflected, but green and blue components are absorbed. The same applies to other painted surfaces, and the luminance of this inclined surface is reduced by the absorbed light. Therefore,
When the light emitting diode elements 1r, 1g, and 1b are not lit, all the light components are reflected as compared with the conventional configuration of FIG.
The contrast can be increased.

In the first embodiment shown in FIG.
5r to 15b and 16r to 16g have substantially the same area. For example, when it is desired to increase the green light output, as in the second embodiment shown in FIG.
The area of 8 g, 19 g is applied to the paint surface 18 r, 18 b,
What is necessary is just to make it wider than the area of 19r, 19b.

In this way, as shown as the light 20, the green light emitting diode element 1g can reflect not only the light in the horizontal direction but also the light in the oblique horizontal direction and emit it to the front, As a result, the green component is intensified, and the reflection of other red and blue components is reduced. Therefore, as mentioned above,
In particular, a predetermined white color can be obtained without increasing the number of the green light emitting diode elements 1g.

Further, as a means for increasing the contrast, it is conceivable to mount a color filter plate in front of the light emitting diode elements 1r, 1g, 1b. That is, since the color filter plate mainly transmits the wavelength of light for each of the light emitting diode elements 1r, 1g, and 1b, it does not affect the emission color. However, external light other than the emission color is attenuated twice when it comes in and when it is reflected inside and goes out again. Therefore, the reflection ratio of external light is extremely low, and the contrast can be increased accordingly.

As shown in FIG. 1, the three color coating surfaces 15
When the areas of r to 15b and 16r to 16g are substantially equal, the color filter plate is also adjusted to the paint surface 1
What is necessary is just to make the combination of three colors of a rectangle which straddle 5r and 16r, 15 g and 16 g of painted surfaces, and 15 b and 16 b of painted surfaces. However, when there is an area difference between the painted surfaces 18r to 18b and 19r to 19g of the inclined surfaces of the partition 13 as shown in FIG. 2, it is necessary to devise the shape of the color filter plate accordingly.

The third embodiment shown in FIG. 3 shows an example of the shape of the color filter plate in such a case. FIG.
2, the color filter plate 21 is mounted on each pixel area 2 shown in FIG. Painting surface 18r-18b, 1
9r to 19g, the color filter plate 21
Since the light use efficiency is improved when the color is divided, the area of the green color filter 22g is reduced by the red and blue color filters 22r and 22r.
2b. If the partition walls 1 have the same colored areas 15r to 15b and 16r to 16g as shown in FIG.
3, the boundary of the color filter plate 21 in FIG. 3 may have a rectangular equal area shape as shown by a broken line.

Further, as another means for increasing the contrast, it is conceivable to apply black paint to a portion of the partition 13 which is not directly related to the optical path, for example, the top portion 23 of the partition 13 in FIG. 1 or FIG. By doing so, the difference in luminance between when lit and when not lit is increased by an amount corresponding to the reduction in the reflection of external light on the black painted top 23, and the contrast is increased. As shown in FIG. 3, a portion 24 corresponding to the top 23 of the color filter plate 21 may be coated with black.

However, in FIG. 2 or 3 of the present invention, other problems may occur. That is, since the area of red and blue is smaller than that of green, the color of the entire display device when viewed from the outside when not lit, that is, the body color looks greenish black. If this change in body color causes a practical problem, it can be corrected by means as shown in FIG.

That is, in the fourth embodiment shown in FIG. 4, a part of the black paint portion 24, which is a boundary portion of the pixel, is made a red paint portion 24r or a blue paint portion 24b. , The tendency of the body color to be green due to insufficient area of the blue portion may be corrected.

In the case of FIG. 4, the vertical stripe portions of the color filter plate 21 are alternately made into red paint portions 24r and blue paint portions 24b, and the horizontal stripe portions are made black paint portions 24k.
And The arrangement of these colors is not limited to this.
r and the blue painted portion 24b. Conversely, the black painted portion 24k may be provided also in the vertical stripe portion. That is,
Each color filter 22r, 22g, 22 of the color filter plate 21
The proportions of the red painted portion 24r, the blue painted portion 24b, and the black painted portion 24k may be determined in accordance with the area ratio of b so that the body color is as black as possible. Of course, the same effect can be obtained by applying each color coating to the top portion 23 of the partition wall 13 in FIG.

In the above embodiment, the light emitting diode elements 1r, 1g, and 1b have been described as having a side emission type having a shape close to a square and having electrodes on both end faces. Alternatively, a light emitting diode bare chip element may be used. Naturally, the present invention can also be applied to those connected by bonding such as a gold wire or an aluminum wire. At this time, a light-transmissive thermosetting resin or the like is injected into the partition 13 so as to cover the chip and the bonding portion, and the sealing is performed. However, the effect of the present invention is not directly affected.

Further, in this embodiment, the inclined surfaces sandwiching the light emitting diode elements 1r, 1g, 1b are color-coded, so that the painted surfaces 15r to 15b, 16r to 16g or 1d.
8r to 18b and 19r to 19g are shown, but this is to paint the color directly on the inclined surface, and
This means both attaching a material such as a seal having each color. That is, the inclined surface may have a reflection characteristic of mainly reflecting light having a wavelength corresponding to each emission color of the light emitting diode elements 1r, 1g, and 1b.

[0031]

As described above in detail, in the light emitting diode matrix display device of the present invention, the inclined surface is formed on the partition wall so as to reflect the light emitted in the side direction of the light emitting diode element in the front direction. Since the inclined surface has a reflection characteristic of mainly reflecting light having a wavelength corresponding to each emission color of the light emitting diode element, without increasing the power of the light emitting diode element or increasing the number of light emitting diode elements. , The brightness can be increased, and the contrast can be increased.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing a second embodiment of the present invention.

FIG. 3 is a perspective view showing a third embodiment of the present invention.

FIG. 4 is a perspective view showing a fourth embodiment of the present invention.

FIG. 5 is a front view showing a conventional example.

FIG. 6 is a side sectional view showing a conventional example.

FIG. 7 is a side sectional view showing another conventional example.

[Description of Signs] 1r, 1g, 1b Light-emitting diode element 2 Pixel area 13 Partition wall 15r, 15g, 15b, 16r, 16g, 16b, 1
8r, 18g, 18b, 19r, 19g, 19b Colored surface 21 Color filter plate 22r, 22g, 22b Color filter 23 Top 24, 24k Black painted portion 24r Red painted portion 24b Blue painted portion

Claims (4)

[Claims] 1. A light-emitting diode matrix display device comprising: a plurality of light-emitting diode element groups each having a plurality of unique luminescent colors arranged in each pixel; and each of the pixels is partitioned by a partition. An inclined surface having an inclination to reflect light emitted in the side direction of the light emitting diode element in the front direction is formed. The reflection mainly reflecting light having a wavelength corresponding to each emission color of the light emitting diode element on the inclined surface. A light emitting diode matrix display device having characteristics. 2. The method according to claim 1, wherein an area ratio of a portion having a reflection characteristic of mainly reflecting light having a wavelength corresponding to each emission color on the inclined surface is made different according to a required light amount of each emission color. The light emitting diode matrix display device according to claim 1. 3. A color filter plate according to claim 1, further comprising a color filter plate arranged to cover each of said sections and transmitting light having a specific wavelength of each of said light emitting diode elements. 13. A light-emitting diode matrix display device according to claim 1. 4. A coating color for correcting a body color is applied to a portion corresponding to the top of said partition wall.
4. The light-emitting diode matrix display device according to any one of items 1 to 3.