JP2901506B2 - LED dot matrix display unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dot matrix display using an LED as a light emitting source, and more particularly, to a unit which can be extended into a unit by arranging these units in rows and columns. Pertaining to the display unit.

[0002]

2. Description of the Related Art FIGS. 2 and 3 show an example of the structure of a conventional LED dot matrix display unit 90 (hereinafter simply referred to as a display unit) of this kind.
As shown in FIG.
For example, 16 rows × 16 as a predetermined pitch P of 2.5 mm
A row of light emitting portions 90a is provided, and the display unit 90 itself has a display function of 16 × 16 dots.

FIG. 3 shows the structure of the display unit 90 in more detail. The case 91 mounts an LED chip 92 at a predetermined position and carries out wiring, and a white printed circuit board 93. A lamp house 94 made of resin or the like, which reflects light from the LED chip 92 and directs the display in the display direction; and a filter 95 made of transparent black to prevent false lighting by irradiation of sunlight or the like. Have been.

At this time, the case 91 has a predetermined pitch between the display units 90 and the light emitting portions 90a of the adjacent display units 90 when the display units 90 are arranged in rows and columns to increase the display area. The dimensions of the constituent members such as the lamp house 94 are adjusted on the outer peripheral side so that P (for example, 2.5 mm) is obtained.

When enlarging the display surface using the display unit 90, the mounting substrate 8 made of, for example, metal is used.
It is fastened on 0 in line with multiple columns or multiple rows.
At this time, as described above, the fastening is performed so that the light emitting portions 90a of the adjacent display units 90 also have the predetermined pitch P (see FIG. 3).

[0006]

However, in the above-described conventional display unit 90, the case 91 (particularly, the lamp house 94) is connected to the ambient temperature and the LED chip 9 at a high temperature.
It is expected that the maximum temperature of about 80 ° C. will be reached due to the heat generated from Step 2. Therefore, the lamp house 94
In order to prevent the lamp houses 94 from interfering with each other even in the state of the highest temperature in consideration of the coefficient of thermal expansion between the resin member on which the mounting member 80 is formed and the metal member on which the mounting substrate 80 is formed. Causes a gap S between the cases 91 in most use conditions (see FIG. 3).

At this time, since the lamp house 94 is made of a white resin, the white color is seen through the gap S, and there is a problem that a white line appears on the display surface, giving a sense of discomfort. In order to solve this problem, means for coloring the side surfaces of the lamp house 94 in black by printing, painting or the like is also used. In this case, when the lamp houses 94 come into contact with each other, the lamp houses 94 are kept in a high temperature state. Because there is, the black paint softens and causes adhesion to both, peeling of the black coating,
Alternatively, a new problem such as a deformation of the lamp house 94 is caused, and is not an essential solution.

In actual practice, each display unit 9
It is extremely impossible to fix the mounting substrate 80 in a state where there is no error between zero. For example, when the mounting is performed with the gap S being narrower than the specified value, the above-described maximum temperature is reached. Lamp house 9
4 and the like. Therefore, it is necessary to consider the accuracy at the time of attachment in the actual gap S, and the gap becomes even wider, and the above-mentioned problems such as deterioration of appearance become remarkable.

[0009]

According to the present invention, as a specific means for solving the above-mentioned conventional problems, a display unit is provided in which a predetermined number of LEDs are arranged in a dot matrix at a predetermined pitch in a case. An LED dot matrix display unit in which a plurality of display units are arranged in a matrix on a mounting board so that a display surface can be enlarged without impairing the predetermined pitch, wherein the case of the display unit is vertically and horizontally. The dimensions are such that the display units are arranged in rows and columns on the mounting board, and when the maximum operating temperature is reached, the size that causes close contact between adjacent display units due to thermal expansion or less, and the side surfaces are injection molded The display unit is formed so as to be covered with an elastomer, and is shrunk on two predetermined sides of the side surface when the display unit reaches a minimum use temperature. Solves the problem by sealing lip for closing the gap that occurs between the display unit that is contacted to provide an LED dot matrix display unit, characterized in that provided by the injection molding the elastomer.

[0010]

Next, the present invention will be described in detail based on an embodiment shown in the drawings. 1 is an LED dot matrix display unit (hereinafter abbreviated as a display unit 1) according to the present invention, and a case 2 of the display unit 1 includes a printed wiring board 4 on which an LED chip 3 is mounted. It is the same as the conventional example in that the light emitting unit 1a is provided at a predetermined pitch P with a lamp house 5 and a filter 6 formed of a white resin.

A plurality of display units 1 are arranged in rows and columns as necessary to enlarge the display surface. At this time, the light emitting portions 1a are also provided at a predetermined pitch between adjacent display units 1. The fixing to the mounting substrate 10 is performed so that P is maintained. Therefore, the case 2 performs the fixing by providing a gap S corresponding to the difference in the thermal expansion coefficient between the case 2 and the mounting substrate 10. This is inevitably the same as in the conventional example.

Here, in the display unit 1 of the present invention, the case 2 is basically formed as a dimension that causes close contact between the adjacent display units 1 due to thermal expansion when the case 2 reaches the maximum operating temperature. In order to make the above easy to understand, the description will be made using more specific numerical values.
Assuming that a is 16 × 16 and the pitch P between the light emitting portions 1a is 2.5 mm, the reference size of case 2 is 4
It becomes 0 × 40 mm.

The case 2 has a minimum operating temperature (2
The case 2 is formed to have a size of 39.8 × 39.8 mm, assuming that it expands by 0.2 mm from 5 ° C.) to the maximum use temperature (80 ° C.) even if the thermal expansion of the mounting board 10 is considered. That is, a gap S of approximately 0.2 mm is generated between the display units 1 at the lowest operating temperature, and close contact occurs between the display units 1 at the highest operating temperature.

In the present invention, in addition to the above structure, the outer periphery, that is, the side surface, of the lamp house 5 is covered with an elastomer for injection molding, for example, urethane rubber. At this time, the lamp house 5 is 39.6 × 39. After being formed of white resin with a thickness of 0.6 mm, the four side surfaces are covered with 0.1 mm-thick urethane rubber by appropriate means such as double molding, and the buffer portion 7 is formed.
Are formed to give a total dimension of 39.8 × 39.8 mm. At this time, the urethane rubber is toned in a dark color such as black.

In addition, a closing protrusion 8 from which the urethane rubber protrudes is provided on two orthogonal sides of the four buffer portions 7 provided on the side surfaces. The projection extends over the entire length of the two sides described above, and the height of the projection is sufficiently reached to the adjacent display unit 1 even at the lowest operating temperature, that is, in this case, it is 0.2 mm or more. It is assumed to be of height. Incidentally, the double molding with urethane rubber is a common means performed to improve the contact feeling when touched by, for example, a camera or binoculars.

Next, the operation and effects of the display unit 1 of the present invention having the above-described configuration will be described. First,
When the display unit 1 is fixed to the mounting substrate 10 at normal temperature (25 ° C.), the gap S
(0.2 mm). In this case, the buffer portion 7 is of a dark color, and the closing projection 8 protruding from the buffer portion 7 is in contact with the adjacent display unit 1. Thus, the lamp house 5 and the mounting board 10 are not viewed, and therefore, no uncomfortable feeling occurs.

Here, when the LED chip 3 is turned on and the ambient temperature rises, the case 2 of the display unit 1 gradually expands. At this time, the closing projection 8 is formed by the same. Since it is deformed so as to be crushed by the flexibility of the urethane rubber or the like, no excessive stress is generated between the adjacent display units 1 and the function of closing the gap S is not lost. When the maximum operating temperature is reached, the buffer portions 7 come into contact with each other, and there is no gap S as originally designed.

The above is a description of the basic part of the operation and effect of the present invention. In reality, all of the display units 1 are fixed to the mounting substrate 10 while maintaining a predetermined gap S. It is inevitable that some variation (for example, 0.05 mm) occurs in the gap S from the viewpoint of assembly accuracy.

In this case, when the gap S is narrower than the reference value, the contact between the buffer portions 7 between the adjacent display units 1 naturally occurs at a temperature lower than the maximum operating temperature, and the temperature becomes lower than the maximum operating temperature. When it reaches the gap S, it expands more than the gap S. However, since the buffer portion 7 is formed of urethane rubber or the like, it is deformed so as to be crushed and the excess is absorbed. Therefore, according to the present invention, it is possible to cope with the variation of the gap S generated on the assembly accuracy.

[0020]

As described above, according to the present invention, when the display unit reaches the maximum operating temperature in a state where the display units are arranged in rows and columns on the mounting board, thermal expansion causes close contact between the adjacent units. A closure that is dimensioned to occur and is formed such that the side surfaces are covered with an elastomer, and that two sides of the side surfaces close a gap created between adjacent display units due to shrinkage when the display unit reaches a minimum operating temperature. When the display units are provided with the projections made of the elastomer, when arranging a plurality of units on the mounting substrate, the white resin lamp house and the mounting substrate must be provided from the gap between the display units in view of the operating temperature range. It is closed with an elastomer covering the sides of the lamp house and a closing projection to prevent discomfort and to improve the quality. It is intended to achieve the.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a main part of an embodiment of an LED dot matrix display unit according to the present invention.

FIG. 2 is a front view showing a conventional example.

FIG. 3 is a sectional view taken along the line AA in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... LED dot matrix display unit 1a ... Light emitting part 2 ... Case 3 ... LED chip 4 ... Printed wiring board 5 ... Lamp house 6 ... Filter 7 ... Buffer part 8 ... Closing projection 10 ... Mounting board P: pitch of light emitting section S: gap

Claims (1)

(57) [Claims] 1. A predetermined number of LEDs at a predetermined pitch in a case
Are arranged in a dot matrix to form a display unit, and an LED dot matrix display unit in which a plurality of the display units are arranged in rows and columns on a mounting board so that the display surface can be enlarged without impairing the predetermined pitch In the above, the case of the display unit has a vertical dimension and a horizontal dimension, and when the display units are arranged in rows and columns on a mounting board and reaches a maximum operating temperature, thermal expansion causes close contact between adjacent display units. It is formed to have dimensions or less and the side surface is covered with an elastomer for injection molding, and two predetermined sides of the side surface between adjacent display units due to shrinkage when the display unit reaches the minimum use temperature. A closing projection for closing a gap generated in the injection molding elastomer is provided by the injection molding elastomer. Torikusu display unit.