JPH1078758A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive, small-sized display device without increasing manufacturing man-hour and mounting man-hour by arranging plural surface mounting type light emitting diodes used as a display member on surface/rear surface both surfaces or one side surface along one side of a printed circuit board facing to a display surface so that its optical axis becomes nearly perpendicular to the printed circuit board surface. SOLUTION: Plural surface mounting type light emitting diodes 2 are mounted along the side of the end part of the printed circuit board 1. The light emitting diode 2 is one with low directivity, and an effective visible angle visualizing emitted light is made 90 deg. or above for the optical axis. The light emitted from the light emitting diodes 2 are visualized viewing the end part provided with the light emitting diodes 2 of the printed circuit board 1 from the direction parallel to the board surface. The light emitting diodes 2 are provided on surface/rear surface both surfaces. Thus, the light emitting diodes 2 provided on the surface/rear surface are made a pair, and displays are controlled at every pair, and visivility is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a PLC (Programmab).
The present invention relates to a display device that displays an operation state of an input / output device such as a le logic controller (NC), a numerical control (NC) device, or a robot.

[0002]

2. Description of the Related Art FIG. 7 shows a configuration example of a conventional display device.
(A) is a perspective view of a display device using a surface-mounted light emitting diode, and (b) is a perspective view of a display device using a through-hole mounted light emitting diode. As shown in FIG. 7A, a display device using surface-mounted light-emitting diodes has a configuration in which a small substrate 102 on which a plurality of surface-mounted light-emitting diodes 103 are mounted is erected vertically on a printed circuit board 101. Has become. In this display device, a light-emitting diode 103 having a high directivity with a small spread of a radiation beam as shown in FIG. 8 is used, so that the surface on which the light-emitting diode 103 is provided is located in front. .

As shown in FIG. 7B, a display device using a light emitting diode of a through-hole mounting type has a plurality of through-holes 104 provided along an edge of a printed circuit board 101, respectively. The configuration is such that a mounting type light emitting diode 105 is mounted. Also in this display device, as in the above-described case, since a light emitting diode 105 having a high directivity is used, the light emitting diode 105 is arranged so that the light emitting surface of the light emitting diode 105 is in front. FIG. 9 shows an example in which the above-described display devices are combined. In the figure, a small board 102 on which a plurality of light emitting diodes 103 are mounted and a plurality of printed circuit boards 101 on which light emitting diodes 105 are respectively provided are housed in a case 106. Each printed circuit board is further provided with a connector 107.
Connection with input / output devices such as LC, NC devices, and robots is possible. Each of the light emitting diodes 103 and 105 is arranged such that each light emitting surface faces the front,
The user can see the light from any of the light emitting diodes.

[0004]

However, the above-mentioned conventional display device has the following problems. In a display device using a surface-mounted light emitting diode,
Since a small substrate (102 in FIG. 7) on which the light emitting diode is mounted is required, operations such as manufacturing of the small substrate and assembling it to a printed circuit board are required, and there is a problem that the number of work steps increases. Fabrication of this small substrate also causes a cost increase. In a display device using a light-emitting diode of a through-hole mounting type, for example, if all components other than the light-emitting diode are surface-mounted, a through-hole must be provided only for mounting the light-emitting diode,
The man-hours for manufacturing and mounting the substrate increase accordingly.

[0005] Further, in any of the display devices, it is necessary to provide a large space for installing a small substrate and a light emitting diode (through-hole mounting type), which hinders downsizing of the device. For example, in the case where a plurality of printed circuit boards are arranged as shown in FIG. 9, it is necessary to secure a space for arranging a small-sized substrate and a light emitting diode (through-hole mounting type), and the apparatus is downsized. The above is a problem.
An object of the present invention is to solve the above-described problems and to provide a low-cost and compact display device without increasing the number of manufacturing steps and mounting steps.

[0006]

In order to achieve the above object, a display device according to the present invention has an effective viewing angle at which light emission can be visually recognized is 90 degrees or more with respect to an optical axis, and is a surface mount type used as a display member. A plurality of light emitting diodes are arranged on both front and back surfaces or on one surface along one side of the printed circuit board facing the display surface such that the optical axis thereof is substantially perpendicular to the printed circuit board surface. In this case, a display device may be configured by providing a plurality of the printed boards. A reflector having an arc-shaped cross section may be provided on both front and back surfaces or one surface of the printed circuit board to reflect light from each light emitting diode in one direction. Further, an optical member for guiding light from the plurality of light emitting diodes may be provided.

[0007] According to the present invention as described above, the light emitting diode has an effective viewing angle at which light emission can be visually recognized at 9 degrees with respect to the optical axis.
At least 0 degree, the light emission can be visually recognized when viewed from a direction parallel to the substrate surface on which the light emitting diodes are provided. Therefore, the light emitting diode can be mounted on a printed circuit board by mounting the light emitting diode on a small circuit board, or by providing a through hole in the printed circuit board and mounting a light emitting diode of a through hole type. With a configuration in which diodes are surface-mounted on a printed circuit board, a display device having visibility equivalent to these can be obtained.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings. <Embodiment 1> FIG. 1 is a perspective view schematically showing a display device according to a first embodiment of the present invention, and FIG. 2 is a view showing a radiation angle of the light emitting diode shown in FIG. A plurality of surface-mounted light emitting diodes 2 are mounted along the edge of the printed circuit board 1. The light emitting diode 2 has a low directivity having an irradiation angle as shown in FIG. 2, and has an effective viewing angle at which the emitted light can be viewed at 90 degrees or more with respect to the optical axis. The light emitted from the light emitting diode 2 can be visually recognized when the end provided with the diode 2 is viewed from a direction parallel to the substrate surface.

The light emitting diodes 2 can be provided on both front and back surfaces of the printed circuit board 1 as shown in FIG.
According to this structure, the light emitting diodes provided on the front and back are paired, and the display can be controlled for each pair, thereby improving the visibility. Further, as shown in FIG. 3B, when the connector 3 is provided on the printed circuit board 1, the light emitting diode 2 can be provided on a portion opposite to the portion where the connector 3 is provided. When the number of mounted light emitting diodes is small, by providing the light emitting diodes 2 on the opposite side of the connector 3 in this way, it is possible to reduce the size of the printed circuit board. FIG. 4 shows an example in which a plurality of display devices configured as described above are provided. In the figure, a plurality of light emitting diodes 2 and
Are mounted in the case 4 in a plural number. Each printed circuit board 1 is arranged such that the end on which the light emitting diode 2 is provided faces the front, and the user can visually recognize the light from the light emitting diode of any substrate.

<Embodiment 2> Here, an embodiment in which the visibility of light from a light emitting diode in the above-described display device is further improved will be described. FIG. 5 shows a second embodiment of the present invention.
It is a perspective view showing the outline of the display of an embodiment. In FIG. 1, a printed circuit board 1 is provided with a plurality of light emitting diodes 2 on both front and back surfaces along a side of a board edge, and an arc-shaped reflecting plate 5 for reflecting light from these light emitting diodes 2 is provided. ing. In this display device, the end on which the light emitting diodes 2 are provided is disposed so as to face the front, and light from each light emitting diode 2 is reflected by the reflector 5 in the front direction. The visibility is better than in the case.

In the display device described above, the light from each light emitting diode 2 is guided by the reflection plate 5, but an optical member such as a prism can be used instead of the reflection plate 5. FIG. 6 shows an example of a display device using this optical member. In FIG. 6, a rectangular parallelepiped optical member 6 is provided at an end of the printed circuit board 1 where the light emitting diode 2 is provided. Light from each light emitting diode 2 can be visually recognized through the optical member 6. Here, the optical member 6 is a light-emitting diode 2 having light incident surfaces provided on both surfaces of the substrate.
The size is such that light from the light is sufficiently incident.

[0012]

As described above, according to the present invention, a conventionally used small substrate or through-hole is not required.
The number of manufacturing steps and mounting steps can be reduced accordingly. In addition, the space required for mounting a small substrate or a light emitting diode (through-hole mounting type) is not required, so that the device can be downsized. In the case of using the reflection plate and the optical member, the visibility is further improved.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a display device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a radiation angle of the light emitting diode shown in FIG.

FIGS. 3A and 3B are cross-sectional views illustrating an example of mounting a light emitting diode.

FIG. 4 is a diagram illustrating an example including a plurality of display devices illustrated in FIG. 1;

FIG. 5 is a perspective view schematically showing a display device according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram showing another embodiment.

7A and 7B are configuration examples of a conventional display device, in which FIG. 7A is a perspective view of a display device using surface-mounted light-emitting diodes, and FIG.
1 is a perspective view of a display device using a light emitting diode of a through-hole mounting type.

FIG. 8 is a diagram showing a radiation angle of the light emitting diode shown in FIG.

FIG. 9 is a diagram showing an example in which the display device shown in FIG. 7 is combined.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed circuit board 2 Light emitting diode 3 Connector 4 Case 5 Reflector 6 Optical member

Claims (4)

[Claims] An effective viewing angle at which light emission can be viewed is 90 degrees or more with respect to an optical axis, and a surface-mounted light emitting diode used as a display member is disposed along one side of a printed board facing a display surface. A display device, wherein a plurality of optical axes are arranged on both front and back surfaces or one surface such that an optical axis thereof is substantially perpendicular to a printed circuit board surface. 2. The display device according to claim 1, wherein a plurality of the printed circuit boards are provided. 3. The display device according to claim 1, wherein a reflector having an arc-shaped cross section is provided on both front and back surfaces or one surface of the printed circuit board, and reflects light from each light emitting diode in one direction. Display device. 4. The display device according to claim 1, further comprising an optical member for guiding light from the plurality of light emitting diodes.