JPH055355B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an improvement in a light-emitting display whose light-emitting portion is constituted by a light-emitting diode chip.

BACKGROUND ART AND PROBLEMS This type of light-emitting display has a large number of light-emitting parts arranged in a matrix on a printed circuit board, and each light-emitting part has a similar light-emitting diode chip (for example, a p-type anode). A matrix circuit is constructed in which these light emitting diode chips are connected in a matrix through conductive patterns formed on the substrate.

Any of the light emitting diodes of such a light emitting section is energized and turned on by a dynamic drive control circuit to display any character, symbol, pattern, etc. as a dot pattern.

By the way, at present, the emitted light color of the light emitting part of the dot matrix light emitting means body as described above is determined by the light emitting diode (hereinafter referred to as
There is only one color determined for each type of LED (LED), and the types of colors are limited. Therefore, the display color of the dot matrix light-emitting display is always the same color, and it is impossible to change the display color midway. Furthermore, since the display colors are limited to these limited types of colors, it is also impossible to display using intermediate colors.

As a means to solve these problems, it is conceivable to configure the circuit structure of the dot matrix light emitting display as shown in FIGS. 14 and 15. That is, in the configuration shown in FIG. 14, each light emitting section 82 arranged in a matrix on the dot matrix light emitting display 81 is provided with three LEDs 1 to 3, each emitting light of a different color. In the configuration shown in FIG. 15, each light emitting section 82 is provided with four LEDs 1 to 4 that emit light of different colors. In such a configuration as shown in FIG. 14, the emitted light colors of the light emitting elements LED1 to LED3 are as follows
For example, red, blue, and green, each light emitting part 8
The anodes of LEDs 1 to 3 are commonly connected to the Y-axis electrode Yn, but the cathodes of each of LEDs 1 to 3 are connected to three independent X-axis electrodes Xan, Xbn,
Connected to Xcn. Similarly, in the one shown in FIG. 15, the emitted light colors of LEDs 1 to 4 are, for example, red,
The colors are blue, green, and yellow.
The anodes of LEDs 1 to 4 are commonly connected to the Y-axis electrode Yn, but the cathodes of each of LEDs 1 to 4 are connected to independent X-axis electrodes Xan, Xbn, Xcn, and Xdn. Here, Xan, Xbn, Xcn,
Xdn and Yn generally represent the terminals of the light emitting section in the nth row and nth column of the matrix circuit.

In a dot matrix light-emitting display body having such a configuration, a predetermined display pattern is obtained by energizing the light-emitting element of the light-emitting section 82 by a dynamic drive control circuit 83 using a computer or the like to obtain a predetermined display pattern. The light emitting elements LED1 to 4 are
Since the Yn electrodes are common, three electrodes Xan, Xbn, Xcn or four electrodes Xan,
By changing the combination of power supplies applied to Xbn, Xcn, and Xdn, the display color can be changed to a desired hue.

However, in such a wiring structure, when forming the matrix circuit necessary for lighting display,
In any of the configurations shown in Figure 15, the
Xan, Xbn, Xcn (hereinafter referred to as X electrode group)
and Yn (hereinafter referred to as Y electrode group), or Xan, Xbn, Xcn, Xdn (hereinafter referred to as X electrode group) and Yn (hereinafter referred to as Y electrode group).
There is a troublesome problem in that five types of electrode groups (conductive patterns) must be provided. Therefore, when a printed circuit board is used as a display substrate, it is necessary to provide a group of Y electrodes on one side of the substrate and a group of X electrodes on the other side, but these wiring structures become complicated and the board work becomes difficult. This complicates the manufacturing process and increases the manufacturing cost, and furthermore, it is impossible to reduce the dot size and dot pitch of the light emitting part 82, so it is necessary to achieve high density integration or increase the number of dots (number of light emitting parts) on the same substrate ( For example, 8x8 dots or 16
There was a problem where it became difficult to do things like x16 dots).

In addition, these dot matrix light emitting display bodies 8
In order to increase the brightness of one light emitting section 82, each light emitting section 82 may be configured with two or more light emitting diodes connected in series. In order to connect the chips in series, it is necessary to provide a conductive land (the surface must be electrolytically plated with gold, silver, etc.) that is isolated and insulated from any conductive pattern, making it easier to create the display substrate. There are problems that will become even more complex.

Purpose of the Invention The light-emitting display of the present invention was made to solve the above-mentioned problems, and is a high-density light-emitting display that simplifies the work of creating a display substrate, improves brightness, and further improves visibility. The object of the present invention is to easily provide a light-emitting display with a large number of dots on the same substrate.

Means for Solving the Problems In order to achieve the above object, the present invention proposes the following two related specific means.

That is, the first invention is a light-emitting display body configured by providing light-emitting diode chips in a light-emitting part arranged in a dot matrix, and in which a conductive pattern and through holes formed on the back surface of a display body substrate are provided. The light emitting unit base is connected to the light emitting unit base by a conductive part formed on the surface of the display substrate and a part of another conductive pattern formed on the surface of the display substrate and insulated and separated from the conductive part. A pair of light emitting diode chips complementary to each other are disposed opposite to the conductive part constituting each light emitting part base and a part of the another conductive pattern, and each set of light emitting diode chips The structure is such that diode chips of different polarity are directly bridged by a bonding wire.

Further, a second invention is a light emitting display body configured by providing light emitting diode chips in a light emitting part arranged in a dot matrix, the display body having a first conductive pattern formed on the back surface of the display body substrate. A conductive portion connected via a through hole and formed on the surface of the display substrate, and a conductive portion formed on the surface of the display substrate,
A light emitting unit base is formed by a portion of the second and third conductive patterns which are insulated and separated from each other, and the conductive unit forming each of the light emitting unit bases and a portion of the second and third conductive patterns are A pair of light emitting diode chips that are complementary to each other are installed in one part, and the different polarities of the light emitting diode chips in each set are connected to each other so that they are directly bridged by a bonding wire. .

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 show examples of vertical cross-sectional structures of light emitting diode chips that are complementary to each other and are used to constitute the light emitting section in both the first and second inventions.

Figure 1 shows the structure of an LED chip in which the p-type anode electrode surface is the upper light-emitting surface.
An n-type GaAs epitaxial layer 104 is provided on the upper surface of the substrate 105, and a p-type GaAs epitaxial layer 103 is further formed on the upper surface. and,
The bottom surface of the n-type GaAs substrate 105 is plated with a gold alloy to form a cathode electrode, and the top surface of the p-type GaAs epitaxial layer 103 is plated with aluminum to form an anode electrode 101. In the example, this type is shown as LEDn (n is a number).

On the other hand, the one shown in FIG. 2 shows the structure of an LED chip in which the n-type anode electrode surface is the upper light emitting surface, and the upper surface of the p-type GaAs substrate 105' is
A GaAlAs epitaxial layer 104' is formed, and an n-type GaAlAs epitaxial layer 103' is formed on the upper surface thereof.
A gold plating layer 102' is formed on the lower surface of the p-type GaAs substrate 105' to form an anode electrode, and an n-type GaAlAs epitaxial layer 10
A gold plating layer 101' is formed on the upper surface of LED 3' to form a cathode electrode (in the following embodiments, this type is indicated as LEDn* (n is a number)).

3 to 5 are diagrams showing an example of the structure of one light emitting part of a dot matrix light emitting display, which is an embodiment of the first invention.

In this embodiment, each light emitting part 11 of the dot matrix light emitting display has a mutually complementary relationship (first
The two chips LED1 and
LED1*, LED2, and LED2* are connected in series to form two series connected bodies 11a and 11b, and these series connected bodies 11a and 11b are connected in antiparallel to form a two-terminal connected body. ing.

Here, Xn indicates a conductive pattern formed on the front surface of the display substrate 2, and Yn indicates a conductive portion connected to the conductive pattern formed on the back surface of the display substrate 2 via the through hole 21.

FIG. 4 is a plan view of the light emitting section 11 formed on the upper surface of the display substrate 2, showing the conductive pattern Xn constituting the light emitting section base B (indicated by diagonal lines) and the conductive section.
Each Yn has light emitting diode chips LED1, LED1* and LED2, which are complementary to each other.
The LEDs 2* are arranged oppositely, and their different polarities are bridge-connected by bonding wires 50, so that two sets of series-connected bodies 11a and 11b are connected in antiparallel. FIG. 5 is a longitudinal cross-sectional structural diagram of the light emitting section 11 shown in FIG. 4. According to the present invention, as shown in this figure, different poles of light emitting diode chips in a complementary relationship to each other,
In other words, since series connection can be achieved simply by connecting the top surfaces with bonding wires, there is no need to form conductive lands, which was conventionally required when connecting chips in series.

In addition, in such a configuration, a pair of mutually complementary light emitting diodes 11 connected in series are used.
If the light emitting colors of a and 11b are made different, it is possible to control the lighting of only the light emitting diodes of the forward biased set, so that the light emitting color can be selectively controlled.

6 to 8 and 9 to 11 each show an embodiment of the second invention.

FIGS. 6 to 8 show an example in which one light emitting section is constructed using three sets of light emitting diodes using a dot matrix light emitting display.

Series connection of three sets of light emitting diodes 11a to 1
1c is constructed, but the light-emitting diode chips in a complementary relationship that constitute each set of series-connected bodies emit light of approximately the same color, and the light-emitting part has three current-carrying terminals Xan, Xbn, and Yn. A lead-out three-terminal connection body is formed. In the figure, LED1 and
LED1*LED2 and LED2* and LED3 and LED3
* indicates light emitting diode chips that are complementary to each other; A conductive pattern 5 formed in the figure and a conductive part connected through a through hole 21 are shown. Note that FIG. 8 is a longitudinal cross-sectional structural diagram of the light emitting section 11 shown in FIG. 7. 9 to 11 show another embodiment of the second invention, in which one light emitting section of a dot matrix light emitting display is constructed using four sets of light emitting diodes.

Series connection bodies 11a to 1 of four sets of light emitting diodes
The mutually complementary light-emitting diode chips composing 1d emit light of substantially the same color, and three current-carrying terminals Xan, Xbn, and Yn are led out from the light-emitting portion. In the figure, LED1 and LED1*, LED
2 and LED2*, LED3 and LED3* and LED4
LED4* indicates light emitting diode chips that are complementary to each other, Xan, Xbn
denotes two conductive patterns formed on the front surface of the display substrate 2 and isolated from each other, and Yn denotes a conductive part connected to the conductive pattern 5 formed on the back surface of the display substrate via a through hole 21. There is.
Note that FIG. 11 shows the light emitting section 11 shown in FIG.
FIG.

In the embodiment of the second invention characterized by the above configuration, in any case, each series connection body 11
The light emission colors of the light emitting diode chips constituting a to 11d are selected to be different, and Xan, Xbn, and Yn are
By changing the combination of voltage polarities supplied between the two, only the forward-biased light emitting diodes are turned on, and various luminous colors can be obtained.
For example, if Yn is the reference level 0, Xan, Xbn
By applying voltages of (+) and (-) polarity, respectively, the set of light emitting diodes that are energized and lit changes, thereby changing the color of the light emitted from the light emitting section 11.

Furthermore, when controlling the lighting of the light emitting section 11, it goes without saying that a desired emitted color can be obtained by controlling the energization by an additive color mixing method that utilizes an afterimage phenomenon. In this case, a plurality of light emitting diodes to be lit to obtain a desired hue are controlled to be lit alternately in chronological order, and by individually controlling the energization time at that time, it is possible to achieve a desired hue. luminescence is obtained.

FIG. 12 shows that when controlling the lighting of the light-emitting display of the present invention, the light-emitting diodes of three types of light-emitting colors, red, blue, and green, constituting each light-emitting part are energized in chronological order to prevent the afterimage phenomenon. FIG. 6 is a diagram showing an example of a control pattern employed when changing the emitted light color of the light emitting unit 11 by the additive color mixing method used. In this control, the dynamic drive control circuit 12 changes the lighting pattern that appears on the display surface of the light emitting display 1 into red,
Since the same time t0 is set for both blue and green, a desired luminescent color is obtained by changing the ratio of the number of times of energization per frame when lighting and displaying the same display pattern. but,
The number of times the display lights up per frame may be the same by changing the energization time for one frame such as t1, t2, and t3.
Shown in Figure 3. Although not shown, the display lighting time per frame may be divided into scans for each row of the matrix, and the display lighting for each row may be changed in chronological order, and such lighting control method is not limited. .

When forming a light-emitting display by applying the present invention, one display board having a light-emitting part of about 8 x 8 dots to 16 x 16 dots is created using a printed circuit board (not shown). A mask plate for improving visibility with a through hole provided at a position corresponding to the light emitting part is arranged on the upper surface of this display substrate, and a through hole part of the mask plate (i.e., a light emitting diode chip is arranged). (emitting part) with a translucent resin (epoxy resin, etc.)
The structure is sealed with In this case, a flexible material (for example, neoprene rubber, silicone rubber, etc.) is used for the mask plate to prevent warping, distortion, cracks, etc. of the display. Further, in order to increase the brightness of the light emitting part, it is desirable that the inner circumferential side surface of the through-hole part be formed to be light reflective (white or silver). In this case, it is desirable to form a concave sealing layer (having a concave upper surface) using a light-transmitting resin in the light-transmitting portion. In this way, the practical dimensions of the light-emitting display formed are, taking a 16 x 16 dot display as an example, the dot diameter φ6.5 mm, the dot pitch 8 mm, and the display surface dimensions.
There is one with a 128 mm square and a mask plate thickness of 2 mm, and another with a dot diameter of φ3 mm, a dot pitch of 4 mm, a display surface size of 64 mm square, and a mask plate thickness of 1.5 mm.

Note that the present invention is not limited to the dot matrix light emitting display described above, but can be applied to all light emitting displays using light emitting diode chips.

Furthermore, although the above embodiments have been described with reference to the embodiments in which conductive lands are not provided, it goes without saying that by providing conductive lands, the number of light emitting diode chips to be connected in series can be increased.

Effects of the Invention As can be understood from the above explanation, according to the light emitting display of the present invention, each light emitting part is constructed using chips that are complementary to each other as light emitting diode chips. They can be connected in series by simply bridging the related light-emitting diode chips with different polarities using bonding wires. Therefore, there is no need for conductive lands as in conventional light emitting displays, and since the light emitting diode chips are connected in antiparallel to the series connection, the number of conductive patterns formed on the display substrate can be further reduced. By reducing the number of conductive patterns on the display substrate, it is possible to save time and effort in forming the conductive pattern on the display substrate, and to facilitate the formation of the conductive pattern on the display substrate.

As a result, it is extremely useful when increasing the brightness of the light-emitting part to increase its density, or when increasing the number of light-emitting dots on the same substrate, and it is possible to provide a light-emitting display that is easy to manufacture. There are advantages.

[Brief explanation of the drawing]

FIGS. 1 and 2 are longitudinal cross-sectional structural views of light emitting diode chips used in the present invention, which are in a complementary relationship to each other, and FIGS. FIG. 3 is a diagram showing an example of a connection configuration of light emitting diode chips constituting a light emitting section, FIG. 4 is a plan view of the light emitting section, and FIG. 5 is a diagram taken along line A-A in FIG. 4. The vertical cross-sectional structure diagrams, FIGS. 6 to 8, are diagrams showing an embodiment of the second invention when applied to a dot matrix light emitting display, and FIG. 6 shows a connection configuration of light emitting diode chips constituting a light emitting part. An example diagram, Figure 7 is a plan view of the light emitting part,
FIG. 8 is a longitudinal cross-sectional structural view taken along the line A-A in FIG. The figure is an example of the connection configuration of light-emitting diode chips that constitute the light-emitting part, Figure 10 is a plan view of the light-emitting part,
Figure 1 is a vertical cross-sectional structural view taken along the line A-A in Figure 10, and Figure 12
13 are explanatory diagrams of the operation in the case of lighting control according to the second invention, and FIGS. 14 and 15 are circuit configuration diagrams of a conventional multicolor lighting dot matrix display. Explanation of symbols, 11... Light emitting section, 11a to 11d
...Series connection body, LED1,1*~LED4,4*
...Light emitting diode chips in a mutually complementary relationship, B...Light emitting part base, 3, 4...Conductive pattern (Xan, Xbn), 5...Conductive part (conductive pattern
Yn), 21...through hole, 50...bonding wire.

Claims (1)

[Claims] 1. Light emitting parts arranged in a dot matrix,
A light emitting display comprising a light emitting diode chip, which is connected via a through hole to a conductive pattern formed on the back surface of the display substrate, and a conductive portion formed on the surface of the display substrate; and a part of another conductive pattern formed on the surface of the body substrate and insulated from the conductive part to constitute a light emitting part base, and the conductive part constituting each light emitting part base;
A set of light emitting diode chips having a complementary relationship to each other is provided in a part of the above-mentioned separate conductive pattern, and the different polarities of the light emitting diode chips of each set are directly bridged and connected by a bonding wire. A light-emitting display using light-emitting diode chips. 2 Light emitting parts arranged in a dot matrix,
A light emitting display including a light emitting diode chip, the conductive portion being connected to a first conductive pattern formed on the back surface of the display substrate via a through hole and formed on the surface of the display substrate. and a portion of the second and third conductive patterns formed on the surface of the display substrate and insulated from each other to constitute a light emitting part base, and the conductive part forming each light emitting part base and ,
A pair of light emitting diode chips having a mutually complementary relationship are provided in a part of the second and third conductive patterns, and the different polarities of the light emitting diode chips of each pair are directly bridged and connected by bonding wires. A light-emitting display using a light-emitting diode chip with a structure that