JPH09297543A - Emissive display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To expand the visual angle in a horizontal direction and to improve visibility. SOLUTION: A main unit 1 includes plural light emitter columns 4a arranged in juxtaposition on a light emitter substrate 2 and plural transmissible lenses 5 which are disposed at every light emitter of these columns so as to cover the light emitting surfaces thereof and have directional characteristics to macroproject the light from the light emitters 4 in the direction along the columns 4a. The substrate 2 is installed in the direction where the light emitter columns 4a are horizontal, by which the light from the light emitters 4 are macroprojected in the direction along the light emitter columns 4a, i.e., horizontal direction by the lenses 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an electronic display such as a vertical signboard type and has a large number of light emitting elements such as LEDs.
(Light emitting diodes) arranged in a matrix, for example, and related to a light emitting display device that displays letters, numbers, symbols, etc. by driving these LEDs using a drive circuit and a control circuit to emit light. Is.

[0002]

2. Description of the Related Art As a conventional light emitting display device of this kind, there is one disclosed in Japanese Utility Model Laid-Open No. 5-81874.

FIG. 17 is a perspective view showing the structure of this conventional light emitting display device. In a conventional light emitting display device 100, a large number of light emitting dots 101 formed on a substrate 103 are mounted on a wiring substrate 102 in a matrix. Wiring board 10
On the back side of the terminal 2, terminals 10 for connecting with a driving circuit are provided.
4 is provided upright, and the heat conductor 105 is provided in a state where the wiring pattern is insulated. This heat conductor 10
A drive circuit board 106 is disposed on the rear surface of the drive circuit 5.
The drive circuit board 106 is provided with a through hole 107 into which the terminal 104 is inserted, a control circuit for designating LEDs to be turned on / off, and a LED for each of the light emitting dots 101 according to a command from the control circuit. A driver (not shown) for lighting is mounted. Reference numeral 115 is a back cover fitted to the peripheral edge of the heat conductor 105.

FIG. 18 is a sectional view taken along line AA of FIG. 17, in which the LED chip 108 is provided at a predetermined position on the surface of the wiring board 102.
Is provided, and one electrode of the LED chip 108 and the wiring pattern 109 on the wiring substrate 102 are connected by a bonding wire 110. Furthermore, LE
The other electrode of the D chip 108 is connected through a through hole 111 to a wiring pattern 112 that is wired up to the back surface.

A conical hole 113 is formed in the substrate 103 so as to surround the LED chip 108. A transparent resin 114 is embedded in the conical hole 113 to form a concave lens.

In the above structure, the drive circuit board 106
When a power source (not shown) is connected to, among the LED chips 108 mounted on the wiring board 102 through the terminals 104,
Only the LED chip 108 designated by the control circuit of the drive circuit board 106 is turned on. Since the conical hole 113 has a shape in which the cross-sectional area increases toward the surface, the transparent resin 114
The LED chip 108 is formed by the lens formed by
The output light is expanded and projected radially, and the light, that is, the display can be seen not only from the front but also from an oblique direction.

On the other hand, the LED chip 108 is of a high brightness type which has a large light emission output. Therefore, considerable heat is generated during operation. This heat is transferred to the heat conductor 105, and the heat is radiated through the heat conductor 105 itself and further through the back cover 115 to prevent the LED chip 108 from overheating.

[0008]

However, according to the conventional light emitting display device, since the light emitted from the LED is radially projected by the lens formed by the transparent resin 114, the luminous intensity is lowered and the outdoor in the daytime. However, there was a problem that the display could not be read.

Therefore, according to the present invention, the light emitting display device has a narrowed viewing angle in the vertical (vertical) direction to increase the luminous intensity and an enlarged viewing angle in the horizontal direction without lowering the luminous intensity to improve the visibility. Is intended to provide.

[0010]

In order to achieve the above object, the present invention provides a substrate, a plurality of light emitter rows arranged in parallel on the substrate, and a light emitting surface for each light emitter of these rows. And a plurality of transmissive lenses having a directional characteristic for enlarging and projecting the light from the light-emitting body in the direction along the row.

According to the above construction, by disposing the substrate in the direction in which the light emitter rows are horizontal, the light from the light emitters is enlarged and projected by the lens in the direction along the light emitter rows, that is, in the horizontal direction.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a right side view showing a light emitting display unit constituting the light emitting display device according to the embodiment of the present invention. This light emitting display unit 1 has a light emitting substrate 2,
The reflector 3, the light emitter 4 and the lens 5 are provided on the front surface side of the light emitter substrate 2, and the insulating sheet 6, the heat dissipation plate 7 and the drive circuit board 8 are provided on the back surface side of the light emitter substrate 2.

The insulating sheet 6 is for preventing a short circuit due to the contact between the wiring pattern of the light emitting substrate 2 and the heat dissipation plate 7 when the heat dissipation plate 7 is closely attached, and has insulating properties such as silicon material and heat resistance. Formed of a material having excellent heat conductivity and heat conductivity, and has substantially the same size as the light emitting substrate 2.
Also, the insulating sheet 6 has a part of the periphery that is a connector pin 9.
The cut is made so as not to hinder the penetration of a.

The heat dissipation plate 7 is made of, for example, aluminum, has a thickness of 2 mm, and has substantially the same shape as the insulating sheet 6. The heat dissipation plate 7 is fixed to the reflection plate 3 by using a plurality of (12 in this embodiment) tapping screws 10 to fasten the insulating sheet 6 and the light emitter substrate 2 together. For this reason, the light emitting substrate 2 and the insulating sheet 6 are provided with the same number of fool holes as the tapping screws 10 in accordance with the mounting position of the tapping screws 10. This heat dissipation plate 7 has not only a heat dissipation function but also a function of preventing deformation (twisting or the like) of the light emitting substrate 2 and maintaining flatness. At the four corners of the heat radiating plate 7, a spacer 11 having a cylindrical shape and at least the surface made of resin is attached by screws 12. By providing the heat dissipation plate 7, even if the light emitting substrate 2 is deformed by heat or the like, the heat dissipation plate 7 corrects the deformation so that the flatness of the light emitting substrate 2 is maintained and an electrical accident is prevented. In addition, it is possible to prevent deterioration of visibility by maintaining the flatness. At the same time, since it has a heat dissipation function, it is possible to prevent the light emitting substrate 2 from overheating.

The light emitter substrate 2 is formed of, for example, a glass epoxy resin material, and is configured to display one character by 16 × 16 (n × m) dots.
Therefore, when displaying four characters, four main units 1 are arranged in parallel. A connector 9 for connecting to the control circuit of the drive circuit board 8 is provided on the back surface of the light emitter board 2.
Are provided at a plurality of locations around the substrate 2.

FIG. 1 is a front view of the light emitting display unit 1. On the surface of the light emitter substrate 2, a plurality of rows of light emitters 4 (light emitter rows 4a) are arranged side by side. In this embodiment, the light-emitting bodies 4 are mounted on the surface of the light-emitting body substrate 2 in a 16 × 16 matrix by the chip-on-board (COB) method. Further, a lens 5 is provided on the surface of the light emitter substrate 2 so as to cover the light emitting surface of each light emitter 4. The detailed configuration of the lens 5 will be described later. The arrangement of the light-emitting bodies 4 is not limited to the matrix shape, and may be staggered.

When it is desired to enlarge the display area, the light emitting substrate 2 can be formed by connecting the light emitting substrates 2 having the same structure to each other vertically and horizontally, and the projections are provided on two sides of the reflection plate 3 for positioning. 13 are provided. In addition, the other 2 on the other side
Recesses 14 are provided on the sides at symmetrical positions with respect to the protrusion 13.

The reflecting plate 3 has the same size as the surface area of the light emitting substrate 2 (for example, 144 mm × 144 mm), is formed of a weather-resistant black resin material, and has a gloss finish. Then, on the surface of the reflecting plate 3, the upper light-emitting element array 4
For example, a partition plate 2a having a height of 8 to 10 mm, which is formed by resin molding, is provided horizontally and vertically at equal intervals so as to partition the a and the lower light emitter row 4a.

FIG. 3 is an enlarged perspective view of an essential part of the reflector 3.
The reflecting plate 3 has through holes 3c provided at regular intervals on a base portion 3b on which a partition plate portion 3a is erected, and a groove 3d having a slightly larger diameter is provided below the through hole 3c. The lens 5 can be positioned and held.

FIG. 4 is a sectional view taken along line BB of FIG. 1, and FIG. 5 is a sectional view taken along line CC of FIG. As shown in FIGS. 4 and 5, the light emitting body 4 is mounted on the surface of the light emitting body substrate 2 so as to be aligned with the center of the lens 5 and fixed by silver paste.

The light-emitting body 4 has at least two or more LED chips as light-emitting elements of different emission colors arranged in a direction along the light-emitting body row 4a (horizontal direction). That is, as shown in FIG. 4, the light-emitting body 4 is an LE whose emission color is R (red).
The LED chip 40A is composed of a D chip 40A and two LED chips 40B having an emission color of G (green), and an LED chip 40A having an emission color of R (red) is mounted in the center so as to match the center of the lens 5. The emission color is G on both sides of the LED chip 40A.
Each (green) LED chip 40B is mounted. The LED chips 40A and 40B thus mounted are
The upper surface is coated with a protective member 15 made of silicon or epoxy resin. This protection member 15 is LE
Not only protect D chips 40A and 40B, but also LED
It also serves to increase the critical angle in the chips 40A and 40B, increase the light output to the outside, and improve the luminous efficiency of the LED.

The lens 5, as shown in FIGS. 4 and 5,
It has a lens body 5a, and a convex portion 5b is formed on the peripheral edge of the lens body 5a. The lens 5 is made of a transparent plastic or glass and has a substantially oval aspherical shape. This convex portion 3b is a through hole 3c of the reflection plate 3.
Is pressed down by the groove 3d, and is pressed against the surface of the luminous body substrate 2 to hold the lens 5.
Therefore, the lens 5 can be mounted without performing bonding or screwing, and a dedicated component for fixing the lens 5 can be omitted. As shown in FIG. 4, the lens 5 expands and projects light from the light-emitting body 4 in a direction along the light-emitting body array 4a (hereinafter, referred to as “XZ plane direction”), and is also shown in FIG. Thus, it has a directional characteristic of condensing the light from the light-emitting body 4 in a direction orthogonal to the light-emitting body array 4a (hereinafter referred to as "YZ plane direction"). Lens 5
Since it can be processed into an arbitrary shape by molding with plastic, desired directional characteristics can be easily obtained, and excellent mass productivity can be obtained. Also, the X-Z of the lens 5
Since the surface direction (horizontal direction) portion is not shielded by the third member, a horizontal visual field can be secured.

FIG. 6 is a circuit diagram of the LED dot matrix. FIG. 7 is a circuit diagram showing one dot pattern. On the mounting surface of the LED chips 40A and 40B of the light emitting substrate 2, the dot patterns shown in FIG. 7 are arranged in a matrix as shown in FIG. As shown in FIGS. 6 and 7, the anode side of the R LED and the G LED is commonly connected in each row, and the cathode side is separately connected to each R and G line.

FIG. 8 is a view showing the back surface of the light emitting display unit 1, showing a mounting state of various electronic components on the drive circuit board 8. The drive circuit board 8 is attached to the end of the spacer 11 with a screw, and the LED chips 40A, 40
A drive circuit (driver) for energizing B is installed. In the figure, 8a is an IC that constitutes a drive circuit.

FIG. 9 shows a drive circuit mounted on the drive circuit board 8. This drive circuit drives the R (red) and G (green) LEDs mounted on the light-emitting substrate 2, and includes a control unit 20 and an R data driver 21 that drives the R LED by the cathode. , G data driver 22 for driving the G LED by the cathode, and the R and G L
Common driver 23 that drives the ED in common with the anode
And The control unit 20 serially inputs the R data and the G data and latches them by a latch signal,
Input the voltage division value from the connection node of the R shift register 20a and the G shift register 20b that output in parallel, the resistors R ₁ and R _{2 of} the RC series circuit connected to the power source Vc, and the capacitors C ₁ and C ₂ , A luminosity adjusting circuit 2 for adjusting the luminosity by controlling a time period for outputting data from the R and G shift registers 20a and 20b according to the value.
0c and 20d, and a protection circuit 20 that outputs a turn-off signal that turns off the light in about 2 ms when the output of the latch signal is stopped
f, a common counter 20g that counts the latch signal and resets the count value by the reset signal, and inputs are connected to the latch signal terminal and the output of the protection circuit 20f,
Outputs are R and G shift registers 20a and 20b
AND gate 20e connected to. The LED matrix formed by the light emitter substrate 2 is 16 × 16.
Display pixels are formed, thereby displaying one character. For example, when displaying four characters, four main units 1 are arranged. At this time, four control units 20 are also arranged, one terminal serves as an input, the other terminal serves as an output, and the input / output terminals are connected between the adjacent control units 20 so that the four control units 20 are connected. Are arranged in series.

Next, the display operation of the present light emitting display device will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 10 is a timing chart showing the display operation of the light emitting display device when four light emitting display units 1 are combined. N shown in the figure is the number of the unit 1 of the LED matrix 16 × 16 described above, and here,
Since four characters are displayed, N = 4. First, the control unit 20 inputs a clock signal at the clock terminal and serially inputs the R and G data to the R and G data terminals. R to G data of 1 to 4 digits is supplied in 16-bit units, and the data of one digit is allocated to the R and G shift registers 20a and 20b of the corresponding unit. At this time, the latch signal falls and the scan advances from common 1 to common 2, and the common counter 20g counts "1".
Next, when the latch signal rises, the shift register 20
a and 20b latch the data of the shift section by the latch section, and when the latch signal becomes high, the AND gate 20e outputs the first output enable signal, and the light intensity adjusting circuit 2
A second output permission signal is output from 0c and 20d,
The driver 2 is driven by the shift registers 20a and 20b for the time period during which the second output permission signal is output.
Data is output to 1 and 22. At this time, the anode of the line corresponding to the count value “1” of the common counter 20g is driven by the common driver 23, and the R and G LEDs of the line are turned on according to the R and G data. During this lighting, the next line, that is, the 16 × 4 data of common 2 is the shift register 2 of R and G.
It is supplied to the shift units of 0a and 20b, and the above operation is repeated. In this way, the common counter 20
When the count value of g reaches “16”, that is, when the display of the common 16 is performed, the display of the cycle of the 16 × 16 LED matrix ends.

According to the light emitting display device having such a structure, the following effects can be obtained.

By arranging the luminous body substrate 2 in a direction in which the luminous body row 4a is horizontal, the light from the luminous body 3 is enlarged and projected in the horizontal direction by the lens 5, so that the viewing angle in the horizontal direction is enlarged. Can be achieved.

Since the lens 5 narrows the viewing angle in the YZ direction (vertical direction) and increases the luminous intensity in the Z axis direction (front direction), the visibility can be improved. Therefore, it is possible to improve the visibility by narrowing the viewing angle in the vertical direction and increasing the luminous intensity, and expanding the viewing angle in the horizontal direction without lowering the luminous intensity.

By providing the partition plate portion 3a for partitioning the light emitter rows 4a, it functions as a reflecting member for vertically reflecting the light from the LED and as a hood for shielding the external light from the vertical direction, and in the daytime. Even when used outdoors, the visibility is not reduced. Incidentally, when the partition plate portion 3a is provided in the vertical direction, the light shielding property from the outside is secured, but the display can be seen only in the range of about 30 ° in the horizontal direction, and the wideness is deteriorated.

A plurality of LED chips 40 having different emission colors
Since A and 40B are arranged in the horizontal direction, it is possible to display a plurality of types of colors while being small in size and to widen the horizontal viewing angle.

[0034]

EXAMPLE FIG. 11 is a diagram showing the shape of the lens 5 in the XY plane according to an example of the present invention, and FIG. 12 is the Y of the lens 5.
FIG. 13 is a view showing the shape on the Z plane, and FIG.
It is a figure which shows the shape in Z surface. As for the shape on the XY plane, on the convex portion 5b side of the lens body 5a, as shown in FIG. 11, the outer diameter in the X direction (column direction) is 7.5 mm and the outer diameter in the Y direction is 6.2 mm. It has an elliptical shape. YZ
As shown in FIG. 12, the lens body 5a on the surface has an elliptical shape with a height of 5.8 mm on the outside, as shown in FIG.
The inside has a semicircular shape with a radius of 2 mm. As shown in FIG. 13, the lens body 5a on the XZ plane has a semicircular shape with an outer diameter of 3.75 mm. Other dimensions are as shown.

FIG. 14 shows a reflector 3 according to an embodiment of the present invention.
FIG. The partition plate portion 3a of the reflection plate 3 has a light emitting element 4
The height from the mounting surface was 8 mm, and the interval between the partition plates 3a was set to the maximum outer diameter of the lens 5 of 8.1 mm. on the other hand,
The lens 5 has a height of 5.8 mm and is slightly lower than the end surface of the partition plate portion 3a. Even if the partition plate 3a is provided by such a combination of the reflection plate 3 and the lens 5,
It does not deteriorate the visibility. Other dimensions are as shown.

FIG. 15 is a diagram showing the directivity characteristic of the lens 5 of this embodiment in the XZ plane direction (horizontal direction), and FIG. 16 is its Y characteristic.
It is a figure which shows the directional characteristic of a-Z surface direction (vertical direction). When the reflector 12 shown in FIG. 14 and the lens shown in FIGS. 10 to 13 are combined, as shown in FIG. 15, it is possible to obtain a directional characteristic in which light is enlarged and projected in the XZ plane direction, and FIG. As shown in, it was possible to obtain the directional characteristics in which the light was condensed in the YZ plane direction.

In the description of the above embodiment, the application example of the light emitting display device is assumed to be a standing signboard type movable display device, but the present invention is not limited to signboards and the like. The present invention can be applied to any dot matrix type display device such as a display board of a vending machine, a guide board in a station or an airport, a department store or a large store.

Further, although the reflection plate 3 is made of resin, it is made of metal and is made by milling or the like.
The surface may be painted black. In this case, it may be necessary to interpose an insulating sheet similar to the insulating sheet 6 with the light emitting substrate 2.

Although an example of controlling a two-color LED has been shown, a single-color LED may be used. Further, although the case where the R and G LEDs are turned on at the same time has been described, they may be turned on at different times. Further, although the COB type is shown in the above embodiment, a discrete type LED element may be used.

[0040]

As described above, according to the present invention, since the light-emitter substrate is installed in the direction in which the light-emitter array is horizontal, the light from the light-emitter is enlarged and projected in the horizontal direction by the lens. The viewing angle in the horizontal direction can be expanded to improve the visibility.

[Brief description of drawings]

FIG. 1 is a front view of a light emitting display unit according to the present invention.

FIG. 2 is a right side view of a light emitting display unit according to the present invention.

FIG. 3 is a perspective view of a main part of a reflector according to the present invention.

FIG. 4 is a sectional view taken along line BB of FIG. 1;

FIG. 5 is a sectional view taken along the line CC of FIG. 1;

FIG. 6 is a circuit diagram of an LED dot matrix according to the present invention.

FIG. 7 is a circuit diagram showing the dot pattern of FIG.

FIG. 8 is a diagram showing a back surface of a light emitting display unit according to the present invention.

FIG. 9 is a block diagram showing a circuit portion of a drive circuit board according to the present invention.

FIG. 10 is a timing chart showing the operation contents when displaying on the light emitting display device according to the present invention.

FIG. 11 is a diagram showing a shape on an XY plane of a lens according to an example of the present invention.

FIG. 12 is a diagram showing a shape on a YZ plane of a lens according to an example of the present invention.

FIG. 13 is a diagram showing a shape in a XZ plane of a lens according to an example of the present invention.

FIG. 14 is a dimensional view showing a reflector according to an embodiment of the present invention.

FIG. 15 is a diagram showing directional characteristics in the XZ plane direction (horizontal direction) of the lens according to the present invention.

FIG. 16 is a diagram showing directional characteristics in the YZ plane direction (vertical direction) of the lens according to the present invention.

FIG. 17 is a perspective view showing a configuration of a conventional light emitting display device.

18 is a partial cross-sectional view showing a cross section taken along the line AA of FIG.

[Explanation of symbols]

 1 Light-Emitting Display Unit 2 Light-Emitting Substrate 3 Reflector 3a Partition Plate 4 Light-Emitting 4a Light-Emitting Row 5 Lens 40A, 40B LED Chip

Claims (4)

[Claims] 1. A substrate, a plurality of rows of light emitters arranged in parallel on the substrate, and a light-emitting surface provided for each of the light emitters of these rows so as to cover the light from the light emitters. A light-emitting display device, comprising: a plurality of transmissive lenses having a directional characteristic for expanding and projecting light in a direction along a row. 2. A substrate, a plurality of rows of light emitters arranged in parallel on the substrate, and a plurality of light emitters of these rows are provided so as to cover the light emitting surface of the light emitters. A plurality of transmissive lenses having a directional characteristic for enlarging and projecting light in a direction along the row, and a plurality of partition plates provided upright between the rows of the light emitters and reflecting light from the light emitters. And a light-emitting display device. 3. The light emitting display device according to claim 1, wherein the lens has a directional characteristic that collects light from the light emitting body in a direction orthogonal to a direction along the row. 4. The light-emitting display device according to claim 1, wherein the light-emitting body is arranged in a direction along the column and is composed of at least two light-emitting elements having different emission colors.