JPH0749509Y2 - Light emitting diode indicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a light emitting diode display used in an information display device provided on a road or at various outdoor stadiums.

[Conventional technology]

In recent years, a display device using a light emitting diode as a display element has come to be used because of its good maintainability and multicolor display capability. Since a light emitting diode has a limit in terms of conversion efficiency from electricity to light, a plurality of light emitting diodes are collectively used as a display dot to form a display device. Further, this LED display has a problem that when it is installed outdoors, it is directly exposed to sunlight and the reflected light reduces the contrast.
As shown in Japanese Utility Model Laid-Open No. 63-35090, a light-emitting diode display is provided with a light-shielding hood on either the upper or lower side.

[Problems to be solved by the device]

The problem when the light-shielding hood is provided above and below the display will be described with reference to FIG. FIG. 5 shows the display surface 1 of the information display device.
FIG. 3 is an enlarged cross-sectional view of the light emitting diode display 2 attached to the display 2, in which light emitting diodes 4 are collectively arranged. The light emitting diode 4 outputs the light emission outputs 5 and 5'to the front, and a user such as a driver obtains information by visually recognizing the light emission outputs 5, 5 '. In front of the light emitting diode display 2, a light shielding hood that constitutes a light absorbing plate is provided integrally with the case, and the sun rays 6 are used for the light emitting diode 4
I try not to hit it directly.

The length 1 of the light-shielding hood 3 is determined by the angle θ1 of the sun rays 6, and the light intensity of the sun rays is important in determining the angle θ1, and the strength of hitting the display surface 1 is the light intensity of sunlight × cos θ1. And becomes stronger when the sun rises. However, when the altitude of the sun decreases, the sun's rays pass through the air layer of the earth for a long distance, so that the intensity of the sun's rays decreases. According to the measurement by the inventor, when the sun altitude is 15 degrees or more, the strength of hitting the display surface 1 is strong, but when the sun altitude is 15 degrees or less, it decreases. Therefore, if the angle at the position of the sun's altitude of 15 degrees is θ1, the length l of the light-shielding hood 3 must be light-shielded at the height h of the display portion, so l = h × cot15 °, and the height h When is 20 mm, the length l is about 75 mm. In this case, the light emission output 5'of the light emitting diode is blocked by the light shielding hood 3 of the lower light emitting diode display 2.

On the other hand, generally, as shown in FIG. 6, the upper limit angle θ3 at which the information display device 8 can be visually recognized from the driver 7 is 7 degrees because it is blocked by the roof of the automobile and the like, which is reported by the Civil Engineering Research Institute of the Ministry of Construction. Therefore, the length l of the light shielding hood against sunlight
If the length is increased, the output 5'of the light emitting diode is blocked,
The angle θ2 becomes smaller. Specifically light emitting diode 4
When t between the light shield hood 3 and 3 is 3 mm, the angle θ2 = tan
^-1 (3/75) ≈ 2.3 °, the upper limit angle θ3 shown in Fig. 6
There was a problem that = 7 ° could not be satisfied. for that reason,
The driver 7 can see the entire light emitting diode 4 only from a distance, and there is a problem that visibility is deteriorated. On the other hand, it is conceivable that the shading hood 3 of FIG. 5 is directed downward like a shading hood 3'shown by a broken line. In this case, the light emission output 5 "of the light emitting diode 4 is directed to the shading hood 3 '. There is a problem that the light-emitting diode 4 cannot be seen when the driver 7 is seen from a distance or when the information display device is installed on the lower side of the downhill, and there is a problem that visibility is deteriorated. .

[Means for Solving the Problems]

In order to solve such a problem, the light emitting diode display according to the present invention eliminates at least one of the upper and lower parts of the lens of the light emitting diode so that the vertical dimension of the light emitting diode is shorter than the left and right dimensions. Is formed on the light emitting display surface whose vertical dimension is shorter than the horizontal dimension.

[Action]

In the light emitting diode display according to the present invention, since the distance between the light emitting display surface and the light shielding hood at the lower end of the light emitting display surface can be increased, the light emitting display surface can be easily seen when the driver looks up at the light emitting display surface.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of a light emitting diode display according to the present invention. FIG. 1 (a) is a side sectional view of the light emitting diode display and FIG. 1 (b) is a front view thereof. In FIG. 1, the same or corresponding parts as those in FIG. 5 are designated by the same reference numerals.

In FIG. 1, the light emitting diode 4 is attached to a printed circuit board 9 inside the light emitting diode display 2 and wired by a printed wiring pattern (not shown).
Power is supplied from the back surface of the power source through the lead wire 10. As shown in FIG. 1 (b), the arrangement of the light emitting diodes 4 is such that the vertical dimension h1 is made shorter than the horizontal dimension h to form the light emitting display surface 1a, and the arrangement thereof is a light shielding hood. It is arranged just under 3 so that the space between it and the light-shielding hood 3 therebelow is set to be t1.

The light emitting display surface 1a formed by disposing the light emitting diodes 4 in this manner prevents the light emitting diodes 4 from being exposed to light when the sunlight 6 is at the same angle θ1 as in FIG. If you decide the length of the protrusion to the front, h1
Since <h, 1 <l (1 is the length of protrusion to the front in the conventional structure of FIG. 5), and the effect of facilitating the cleaning of dirt on the surface of the light emitting diode 4 is obtained. Further, by setting the distance t1 between the light emitting diode 4 and the lower light shielding hood 3 to be t1> t and 1 <l, the first
The angle θ2 ′ = tan ⁻¹ (t1 / 1) shown in the figure can be increased. This makes it possible to satisfy the driver's 7 (see FIG. 6) upper visibility limit angle of 7 degrees, and to prevent direct sunlight from the sunlight 6 to the light emitting display surface 1a by the light shielding hood 3 without reducing the visibility. It becomes possible to block light.

Specifically, when θ1 is set to 15 degrees, the vertical dimension h1 is reduced from the dimension h = 20 mm by 5 mm to 15 mm, and the interval t1 is increased by 5 mm to 8 mm, 1 = h1 × cot15 ° = 15 × cot15 ° ≈ 56 mm, θ2 '= tan ^-1 (8/56) = 8.1 °, and the upper limit angle θ3 = 7 ° shown in Fig. 6 can be satisfied.

In FIG. 1, the shaded portion 10a prevents rainwater from entering the electric wiring portion such as the mounting portion of the printed circuit board 9 of the light emitting diode 4 and the light emitting diode 4 when the light emitting diode 4 is not emitting light. A black waterproof resin filled to reduce the reflected brightness of external light that hits the display and increase the brightness ratio between those that emit light and those that do not, such as silicone resin and epoxy resin. Has been.

As shown in the front view of the light emitting diode display of FIG. 1 (b), the light emitting display surface 1a formed by the arrangement of the light emitting diodes 4 has a vertical dimension h1 <horizontal dimension h. When viewed from a distance, it cannot be read in landscape orientation due to the resolution of the human eye and the phenomenon of light bleeding due to the luminescent display, and it appears as one point, which does not cause a visual problem.

Next, the light emitting diode used in the embodiment of FIG. 1 will be described with reference to FIGS. 2 (a) and 2 (b). 2 (b) is a front view, and FIG. 2 (a) is A- in FIG. 2 (b).
It is an A'cross section figure. In FIG. 2, 4 is a light emitting diode, and 11 is a lens made of transparent resin. Inside this lens 11, a reflecting mirror 12 formed on a lead wire 13 is provided.
And the light emitting diode chip 14 on the reflecting mirror 12 are mounted, and the light emitting diode chip 14 is bonded to the electrode 15 by the wire 16. As shown in FIG. 2 (b), the lens has a circular shape with a diameter of φ1 and the tip has a hemispherical shape as shown in FIG. 2 (a). The light emitting output 5 of the light emitting diode chip 14 is reflected. The light is reflected by the mirror 12 and is output in a desired direction by the lens 11. First
As shown in the figure, it is necessary to downsize the light emitting diode 4 in order to shorten the vertical dimension h1.
Since the structure requires the reflecting mirror 12 and the electrode 15 and the spread of the light emission output in the left and right direction as shown in FIG. 2 (b), there is a limit to the removal of unnecessary parts in the left and right direction. is there. However, in the vertical direction, by disposing the electrodes 15 in the horizontal direction, it is sufficient to leave only the necessary part of the lens in the vertical direction. Therefore, as shown in FIG. 2A, if the angle θ3 of the light emission output 5 ″ is set to the angle θ2 ′ of FIG. 1, the angle θ4 of the light emission output 5a is θ4.
Since> θ3, the light emission output 5a at this angle θ4 is unnecessary. Therefore, by removing the shaded portion 17 as shown in FIGS. 2A and 2B, the vertical dimension can be set to φ2 <φ1 and the vertical dimension can be reduced.

Next, in FIG. 2, the case where the number of the light emitting diode chips 14 is one has been described, but the case where the number of the light emitting diode chips 14 is two as shown in FIG. 3 will be described. FIG. 3 is a front view of the light emitting diode, and since the reflecting mirror portion is divided into two parts 12 and 12 'and the electrode 15 is required, miniaturization in the left-right direction becomes more difficult than in the case of one chip 14. In the figure, the same or corresponding parts as those in FIG. 2 are designated by the same reference numerals.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a front view of a light emitting diode display, in which the same or corresponding parts as in FIG. 1 (b) are designated by the same reference numerals. In FIG. 4, the vertical dimension S of the case 2'is such that S <horizontal dimension T so that the light emitting diode 4 can be housed, and a space R can be provided between the upper and lower light emitting diode display surfaces 1a. . This allows
The heat dissipation of the light emitting diode can be improved, and further, the heater wire 18 for snow melting can be provided as a countermeasure when snow is accumulated on the light shielding hood 3.

In the above description, the shape of the light emitting diode is described as an oval shape, but the present invention does not limit the shape. Further, the number of 16 has been described, but the number is not limited to this.
Further, although the light emitting diodes are described as being arranged in a rectangular shape, the shape is not limited, and needless to say, an oval shape, an elliptical shape, or the like may be used. Further, although the description has been made by removing the upper and lower unnecessary portions in order to reduce the vertical dimension of the light emitting diode, either the upper portion or the lower portion may be removed, and the upper and lower deleted dimensions may be changed. Needless to say. Further, it is needless to say that the deletion in the left-right direction may be deleted as long as it can be downsized.

[Effect of device]

As described above, the present invention eliminates at least one of the upper part and the lower part of the lens of the light emitting diode so that the vertical dimension of the light emitting diode is shorter than the left and right dimension, and the vertical dimension in the array of light emitting diodes is shorter than the left and right dimension. By forming it on the light emitting display surface, the vertical dimension of this light emitting display surface can be made large because the distance between the lower end of this light emitting display surface and the light shielding hood arranged below this light emitting display surface can be increased. The distance between the light emitting display surface and the lower light shielding hood can be increased, which makes it easier to see the light emitting display surface when the driver looks up at the light emitting display surface, and the light output of the light emitting diode is not blocked by the light shielding hood. There is an effect that an information display device with good visibility can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view and a front view showing an embodiment of a light emitting diode display according to the present invention, and FIGS. 2 (a) and 2 (b).
1 is a sectional view and a front view showing an example of a light emitting diode which constitutes the device of FIG. 1, FIG. 3 is a sectional view showing another embodiment of the light emitting diode which constitutes the device of FIG. 1, and FIG. FIG. 5 is a front view showing a second embodiment of a light emitting diode display according to the present invention, FIG. 5 is a sectional view showing a conventional light emitting diode display, and FIG. 6 is an explanatory view showing a relationship between a driver and an information display device. . DESCRIPTION OF SYMBOLS 1 ... Display surface, 1a ... Light emitting display surface, 2 ... Light emitting diode indicator, 2 '... Case, 3 ... Light-shielding hood, 4 ... Light emitting diode, 5' ... Light emission output, 6 ... Sun rays, 9 ... Printed circuit board, 10 … Lead wire, 10a… Resin for waterproofing.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-202465 (JP, A) Actual application Sho-61-128938 (Actual opening Sho-63-35090) A microfilm (JP, U) of which the contents were photographed. A microfilm (JP, U, U) of which the detailed description and drawings attached to the application for actual application Sho 58-147575 )

Claims (1)

[Scope of utility model registration request] 1. A light-emitting display surface having a plurality of light-emitting diodes arranged vertically and horizontally on a printed circuit board on which a printed wiring pattern for power supply is formed, and a light-shielding hood is provided at an upper end of the light-emitting display surface. In the light emitting diode display disposed in front of the front end of the light emitting display surface, at least one of the upper and lower parts of the lens of the light emitting diode is deleted to make the vertical dimension of the light emitting diode shorter than the horizontal dimension, A light emitting diode display characterized in that a vertical dimension in an array of light emitting diodes is formed on a light emitting display surface shorter than a horizontal dimension.