JP3832977B2 - Dot matrix display - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dot matrix display device using a chip-type light emitting element. More specifically, the present invention relates to a dot matrix display device having a particularly strong directivity on the front side while having a certain degree of directivity around the periphery.
[0002]
[Prior art]
In the conventional dot matrix display device, for example, as shown in a perspective view of FIG. 3, for example, chip-type light emitting elements (hereinafter referred to as LEDs) 52 are arranged in a matrix on the surface side of the display panel substrate 51. A drive circuit (not shown), a power supply terminal for each LED 52, and the like are provided on the back surface of the display panel substrate 51, and desired LEDs and characters are displayed by selectively turning on and off the LEDs 52 arranged in a matrix. It is configured. Many display devices are arranged vertically and horizontally and used as a large display board in a public bulletin board or the like.
[0003]
As described above, a chip-type LED and a lamp-type LED may be used as the LED 52 used in this display device. As shown in a perspective view of an example of the chip type LED in FIG. 4A, the LED chip 52 a is die-bonded on the insulating substrate 55, and a wire is connected to the electrode provided on the surface of the insulating substrate 55. 56 is formed, and the package 57 is formed by covering the periphery with a transparent resin so that the upper surface is flattened. In addition, a reflector may be provided around the package 57 so that light is not emitted right beside, or two or more LED chips 52a of different colors may be encapsulated. Further, in the lamp type LED, as shown in the sectional view of FIG. 5A, the LED chip 52a is die-bonded to the curved portion 61a at the tip of one lead 61, and the other electrode is the other lead. A package 64 is formed by bonding the wire 62 and the wire 63 and covering the periphery thereof in a dome shape with a transparent resin.
[0004]
[Problems to be solved by the invention]
As described above, in the dot matrix display device using the LED, there are a case where a chip-type LED is used as the LED and a case where a lamp-type LED is used. Generally, the chip-type LED is shown in FIG. As shown in the radiation characteristics, when light is emitted in all directions and a display board is configured using this, it is easy to see from an oblique direction without looking from the front, but it becomes weak because the light spreads throughout, and the front There is a problem that it is difficult to recognize from a distance. On the other hand, when a lamp-type LED is used, as shown in FIG. 5 (b), the radiation characteristic is reduced to the front side by the dome-shaped package, and strong light is emitted to the front side. When the display board is configured using this, it is difficult to recognize from the diagonal direction, and the display board that is observed by a large number of public unspecified people depends on the direction. There is a problem that it is difficult to see.
[0005]
For example, as disclosed in JP-A-6-104488, a dot matrix in which chip LEDs are arranged in a matrix so that light spreads in the left-right direction of the display board and does not spread in the vertical direction. There is disclosed a structure in which a cylindrical lens or a lens having different curvatures in the vertical direction and the horizontal direction is provided on the front side of the display device. However, in public displays such as destination guides for stations and the like, a short person may look up from below, and light is emitted in all directions, and a dot matrix display device that collects light as brightly as possible and displays it as brightly as possible. It is requested. Further, when such a lens is externally attached, it is required that its mounting structure is simple and does not lead to an increase in cost.
[0006]
The present invention has been made to solve such a problem. Even when a large display board is configured by arranging a large number of dot matrix display devices using LEDs, the viewing angle is wide and can be applied in any direction. An object of the present invention is to provide a dot matrix display device that makes it easy to see from a distance and makes it easy to recognize from a distance by increasing its brightness.
[0007]
[Means for Solving the Problems]
A dot matrix display device according to the present invention includes a display panel substrate, chip-type light emitting elements arranged in a matrix on the display panel substrate, and a lens in which a convex portion is formed so as to coincide with each of the chip-type light emitting elements. A cover case that escapes the convex portion of the lens case and presses the flat surface portion, and a caulking pin is provided in the cover case, and the caulking pin penetrates the lens case and the display panel substrate, and the display panel It is fixed by caulking on the back surface of the substrate.
[0008]
Here, the chip-type light-emitting element means a light-emitting element in which a light-emitting diode chip is bonded to a planar substrate surface and the periphery thereof is coated so that the surface is flat, and two or more light-emitting diode chips are provided. In other words, it includes a case where a light shielding wall is provided around the side wall and a case where a light shielding wall is not provided around the side wall.
[0009]
With this structure, light is radiated through a lens case having a convex portion on the front surface of light whose directional characteristics are spread by a chip-type LED. Since it is condensed to some extent by the lens, intense light is emitted over a wide area on the front side. That is, it is possible to obtain a dot matrix display device having a directivity and light intensity that are intermediate between the conventional chip-type LED and lamp-type LED.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, the dot matrix display device of the present invention will be described with reference to the drawings.
[0011]
The dot matrix display device of the present invention has chip-type LEDs 2 arranged in a matrix on the display panel substrate 1 as shown in FIGS. 1A to 1C in plan and side views and a partial sectional view thereof. Is arranged on the chip-type LED 2, and a lens case 3 is formed on the chip-type LED 2 so as to match the respective chip-type LEDs 2. It consists of a cover case 4 to be pressed. As will be described later, the lens case 3 is sandwiched by caulking pins provided on the cover case 4 and fixed on the back surface of the display panel substrate 1 by caulking. In FIG. 1, 5 is a mounting plate, and 6 is an air vent hole.
[0012]
The display panel substrate 1 is made of, for example, an aluminum core substrate, and a wiring pattern (not shown) is formed on the surface thereof. The display panel substrate 1 is connected to each electrode of the chip LED 2 mounted on the surface. Note that a circuit such as a control circuit for controlling on / off of each LED and a resistance unit for driving the LED 2 is formed on the back surface of the display panel substrate 1, but is omitted in the drawing.
[0013]
As shown in FIG. 1C, the chip-type LED 2 is provided with terminal electrodes 22 and 23 from both ends of the surface of the insulating substrate 21 to the side surface, and the LED 22 is provided on one of the electrodes 22. The chip 24 is die-bonded. The other electrode of the LED chip 24 and the second terminal electrode 23 are electrically connected by a wire 25 such as a gold wire. Then, the periphery is covered with a transparent epoxy resin or the like, and a package 26 having a flat surface is formed. In the example shown in FIG. 1C, a reflection wall 27 is provided on the outer peripheral side of the package 26 so that light does not travel to the side and is efficiently emitted to the upper surface side. However, unlike the lamp type LED, the LED chip 24 is bonded to the flat portion, unlike the LED chip 24 bonded to the curved portion at the tip of the lead, and the light emitted in the lateral direction is away from the LED chip. Since the light is reflected upward by the light shielding wall 27, the radiation beam has a wide directivity. The chip LED 2 has terminal electrodes 22 and 23 at both ends thereof electrically connected and fixed on the wiring pattern of the display panel substrate 1 by solder 28 or the like.
[0014]
In the example shown in FIG. 1A, two units are connected, but 16 × 16 or 24 × 24 LEDs 2 are attached to one unit. And, for example, when configuring a large display board used for a station destination display or a public bulletin board, a large number of these units are arranged in one column or a plurality of columns, one character is displayed by one unit, A large-sized display board is configured by sequentially changing and displaying a continuous character string, scrolling, or arranging a large number of units vertically and horizontally and displaying them as a whole.
[0015]
As shown in an exploded view of the lens case 3 and the cover case 4 in FIG. 2A, the lens case 3 corresponds to the position of the LED 2 on one surface side of a plate-like body made of, for example, acrylic or polycarbonate. Protrusions 3a are formed in the portions, and can be easily manufactured by pouring acrylic, polycarbonate resin or the like into a mold. The shape of the convex portion 3a is, for example, a sphere shape so as to cover the light emitting portion of each chip LED. However, even if it is not a perfect sphere shape, it may be formed substantially symmetrically with respect to the central axis. That's fine. Although this convex part 3a has a function which condenses light to some extent, light does not necessarily enter with parallel light, and light is radiated | emitted by all directions with wide directivity on the surface of chip-type LED2. The light that enters the convex portion 3a also enters in all directions. For this reason, the light emitted from the convex portion 3a does not completely converge on the central axis and exits in all directions, but does not spread to the outside due to the convex lens effect and is condensed to some extent. Since the surface opposite to the surface on which the convex portion 3a of the lens case 3 is formed is plate-like and flat as described above, it can be stably stacked by placing it on the surface of the chip-type LED 2.
[0016]
The cover case 4 is a plate-like body made of black PPE, PC, ABS or the like, and has a notch in the portion corresponding to the convex portion 3a of the lens case 3 described above, and holes 4b are formed in a matrix. ing. On the back side, caulking pins 4a are provided, for example, at about four places. The caulking pin 4a is formed to have a length that is about several mm longer than the sum of the thickness of the lens case 3 and the thickness of the display panel substrate 1 and the LED 2. Through holes 3b and 1b are also formed in the lens case 3 and the display panel substrate 1 corresponding to the position of the caulking pin 4a in advance, and the cover case 4 is replaced with the lens case 3 as shown in FIG. The caulking pins 4a are penetrated to the back surface of the display panel substrate 1 so as to overlap the front surface side, and the caulking pins 4a are caulked on the back surface of the display panel substrate 1, thereby being fixed.
[0017]
According to the dot matrix display device of the present invention, the chip-type LEDs are arranged in a matrix, and the lens case in which the convex portion is formed for each LED is provided, so that light is emitted in a wide direction. In addition, light is condensed on the front side of the display device, and a display device with a wide viewing angle and high luminance is obtained. That is, in the conventional lamp-type LED, the LED chip itself is placed in a bowl-shaped recess and further covered with a dome-shaped package, so that light is emitted from the center of the dome, and most of the LED chip is located near the center line of the dome. Since the light is condensed and emitted, strong light is emitted in the shape of the central axis, but the intensity of light is extremely weak in the lateral direction shifted from the central axis, making it difficult to see from the oblique direction. However, according to the display device of the present invention, since the surface of the chip-type LED is radiated in all directions on the surface side with a wide directivity, and the convex lens is provided on the surface side, it is directed obliquely. The light that comes out is bent to the front side to some extent, but is not completely bent to the center side, but is only concentrated to some extent on the front side. Therefore, the light is irradiated in a fairly wide range rather than an extremely narrow viewing angle as in the case of the lamp type LED, but not so wide in the lateral direction as in the case of the chip type LED, and strong light is irradiated on the front side. As a result, a display device having a wide viewing angle and a relatively high luminance can be obtained, which is most suitable for a display device in which a large number of people like a public display observe from various directions. In addition, it can observe in the wide range from the left-right direction and the downward direction by forming the convex part so that it may become substantially symmetrical with respect to the central axis.
[0018]
Furthermore, according to the dot matrix display device of the present invention, it is possible to form a convex lens on the surface of each chip-type LED simply by sandwiching and crimping the lens case with a cover case while easily manufacturing the lens case by molding or the like. Can be manufactured very easily. That is, if it is going to form a convex part on the surface of chip type LED, a resin application process etc. will be needed, but according to this invention, a lens case can be formed easily and the lens By simply fixing the case with the cover case, it is possible to easily collect light with a wide directivity to some extent.
[0019]
【The invention's effect】
According to the present invention, it is possible to obtain a display device having a large brightness on the front side while widening the viewing angle of the dot matrix display device with a simple structure. As a result, a public display device such as a station destination display or lightning news can be observed by many people at once from all directions, and the display device can be firmly recognized from a distance.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an embodiment of a dot matrix display device of the present invention.
2 is an exploded explanatory view of a lens case and a cover case portion of FIG. 1 and a cross-sectional explanatory view of a portion to be fixed to a display panel. FIG.
FIG. 3 is an explanatory perspective view of an example of a conventional dot matrix display device.
4 is a diagram showing an example of LEDs used in the display device of FIG. 3 and their directivity characteristics.
5 is a diagram showing another example of LEDs used in the display device of FIG. 3 and their directivity characteristics.
[Explanation of symbols]
1 Display panel board 2 LED
3 Lens Case 3a Convex 4 Cover Case 4a Caulking Pin

Claims (1)

A display panel substrate; chip-type light-emitting elements arranged in a matrix on the display panel substrate; a lens case formed with a convex portion so as to match each of the chip-type light-emitting elements; and the convex of the lens case The cover case is provided with a caulking pin, and the caulking pin passes through the lens case and the display panel substrate and is fixed by caulking on the back surface of the display panel substrate. A dot matrix display device.

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