JP4592409B2 - Light guide plate type display device - Google Patents

Description

  The present invention relates to a light guide plate type display device, a sign, and a road sign that can be favorably visually recognized at night using a light guide plate.

  The light emitted from the light source is introduced into the light guide plate from the end face of the light guide plate, and the light introduced by the reflective surface provided on one side of the light guide plate is emitted to the front side, so that it is good even at night 2. Description of the Related Art A light guide plate type display device that can visually recognize a display unit has been often used. As the light source, a cold cathode tube and a fluorescent tube are often used, but in recent years, a light emitting diode (also referred to as an LED) having a long life as a light source is increasing.

  Tubular light sources such as cold-cathode tubes and fluorescent tubes can obtain almost uniform emission brightness except for the vicinity of both ends, but LEDs have a small light-emitting area that can be irradiated by a single unit, and a plurality of LEDs are arranged in a row. When light is incident on the light guide plate, there is a risk of uneven brightness between the light sources. In order to solve such a concern, for example, a light guide plate having a plurality of point light sources, an incident surface on which the plurality of point light sources are arranged to face each other, and an exit surface that emits light incident from the incident surface. And a reflecting member for causing the light from the point light source to enter the incident surface, and one end of the reflecting member is formed on the exit surface at a plurality of portions corresponding to between the point light source and the point light source in the vicinity of the incident surface. A bonded surface light source device is disclosed.

JP 2001-43721 A

  However, since LEDs are essentially smaller in the directivity of light rays than cold cathode fluorescent tubes and fluorescent tubes, it is possible to completely prevent the light emission luminance from the light guide plate closest to the light source from being lowered even if measures are taken as described above. I can't. In addition, when the light guide plate becomes large, it is necessary to arrange a large number of LEDs. This increases the cost, and the design related to the light reflection of the reflection surface of the light guide plate in order to make the brightness of the entire light guide plate uniform. Becomes annoying.

  The present invention has been made in view of the problems as described above, and even when an LED is used as a light source, it is possible to sufficiently obtain the light emission brightness closest to the light source, and it is inexpensive even if the light guide plate is large. It is intended to provide a light guide plate type display device, a sign and a road sign that can make the brightness of the entire light guide plate uniform at a low cost.

In order to achieve the above object, the present invention is configured as follows. That is, the light guide plate type display device according to the present invention includes a planar rectangular light guide plate, and light emitted from a vertically placed light source and a horizontally placed light source respectively on a longitudinal end surface and a lateral end surface of the light guide plate. Is arranged so as to be incident on the light guide plate, and a frame is formed around the light guide plate, the vertical light source and the horizontal light source are accommodated in the frame, and the vertical light source is The horizontal light source is a cold cathode tube and / or a fluorescent tube, and a reflector is provided on the side opposite to the light introduction direction of the horizontal light source. The light is introduced into the light guide plate from the two directions of the vertical light source and the horizontal light source, and the illumination unevenness caused by the vertical light source formed as an LED is reduced by the horizontal light source. It is a feature.

  According to the light guide plate type display device according to the present invention, either one of the vertical light source and the horizontal light source is a cold cathode tube and / or a fluorescent tube, and the LED of the other light source is in the cold cathode tube. And / or the amount of light is supplemented by a fluorescent tube, and even when an LED is used as a light source, it is possible to sufficiently obtain the light emission brightness in the immediate vicinity of the light source. Compensate illumination unevenness with light of uniform brightness emitted from cold cathode fluorescent lamps and / or fluorescent tubes, and evenly make the brightness of the entire light guide plate uniform even at a low cost even if the light guide plate is large. Can do.

  Further, if the cold cathode tube and / or the fluorescent tube are arranged on the end face in the lateral direction of the light guide plate, the accumulation of the residue due to the bias of the gas enclosed in the cold cathode tube and / or the fluorescent tube due to gravity and light emission. Therefore, the degree of hindering discharge can be reduced, which is preferable.

To Also sign can Rukoto includes a light guide plate type display device according to claim 1 of the present invention.

According to such a sign, an internally-illuminated sign using a light guide plate has been used in various ways because it is thin and increases the degree of freedom of installation. Although high cost is cited as a difficulty, it may be possible to easily install the light guide plate type display device according to the present invention by reducing the difficulty.

To or road signs can Rukoto includes a light guide plate type display device according to claim 1 of the present invention.

According to such a road sign, an internally illuminated road sign using a light guide plate has been used in various ways because it is thin and increases the degree of freedom of installation. Although generation and high cost are cited as difficulties, it may be possible to reduce the difficulty by using the light guide plate type display device according to the present invention and to easily install it.

  According to the light guide plate type display device according to the present invention, either one of the vertical light source and the horizontal light source is a cold cathode tube and / or a fluorescent tube, and the LED of the other light source is in the cold cathode tube. And / or the amount of light is supplemented by a fluorescent tube, and even when an LED is used as a light source, it is possible to sufficiently obtain the light emission brightness in the immediate vicinity of the light source. Compensate illumination unevenness with light of uniform brightness emitted from cold cathode fluorescent lamps and / or fluorescent tubes, and evenly make the brightness of the entire light guide plate uniform even at a low cost even if the light guide plate is large. Can do.

  BEST MODE FOR CARRYING OUT THE INVENTION The best embodiment according to the present invention will be specifically described below with reference to the drawings.

  FIG. 1 is a front view showing an embodiment of a light guide plate type display device according to the present invention. In the light guide plate type display device 10, a frame body 4 is formed around a rectangular light guide plate 1, and a vertical light source 2 and a horizontal light source 3 are accommodated in the frame body 4. In this figure, the display unit is omitted, and the front side of the frame body 4 is partially broken, and the vertical light source 2 and the horizontal light source 3 are drawn so as to be visible from the front side. When the light guide plate type display device 10 is installed, the direction α is upward, but the vertical light source 2 that is an LED attached to the substrate 21 facing the vertical end surface 11 of the light guide plate 1 is spaced vertically. The light is incident in the direction β from the vertical light source 2 to the vertical end face 11. Further, a horizontal light source 3 that is a cold cathode tube is provided directly opposite the lateral end surface 12 of the light guide plate 1, and light is emitted from the lateral light source 3 in a direction γ perpendicular to the direction β with respect to the lateral end surface 12. A reflector 31 is provided on the side opposite to the direction γ of the lateral light source 3.

  Since the vertical light source 2 is an LED having a small light directivity angle, the vertical light source 2 alone may cause a shortage of light emission luminance in the vicinity of the end surface 11 in the vertical direction and uneven illumination along the direction β. By introducing uniform light into the light guide plate 1 by the horizontal light source 3 in the direction γ orthogonal to the direction β, light is introduced into the light guide plate 1 from two directions, and the light emission luminance of the entire light guide plate 1 is improved. In addition to improving visibility, the horizontal light unevenness caused by the vertical light source 2 is drastically erased by the uniform vertical light of the horizontal light source 3, which is much higher than when only the vertical light source 2 is provided. Irradiation unevenness can be reduced, and the respective advantages of using the LED and the cold cathode tube as the light source can be fully utilized.

  Further, the vertically placed light source 2 uses an LED that is not adversely affected by gravity, and a cold cathode tube that is easily affected by gravity is used as the horizontally placed light source 3 so that light enters the light guide plate 1 from two directions. In this case, the gas sealed in the cold cathode tube is only biased in the cross-sectional direction with a small distance, and the adverse effect due to the bias is reduced, and the residue generated by the light emission is also deposited below the cross-sectional direction. The life as a light source can be extended without hindering.

  In particular, when the light guide plate 1 is a large one having, for example, a short piece direction of 2 m or more, the vertical light source 2 and the horizontal light source 3 are placed in the opposite vertical direction across the light guide plate 1. The light guide plate 1 may be provided on the end face 11 and the end face 12 in the lateral direction to introduce light into the light guide plate 1 from four directions so that the light can easily reach the entire light guide plate 1.

  Furthermore, if an internally illuminated sign is formed using the light guide plate type display device 10 as described above, a sign with little illumination unevenness can be obtained even at a large cost. Further, when applied to road signs, the road signs are required to have a large size as the light guide plate type display device. However, by using the light guide plate type display device 10 according to the present invention, the advantages of the light guide plate type can be easily utilized. It is possible to obtain an internally illuminated road sign.

It is a front view of the partial wave front which shows one Embodiment of the light-guide plate type display apparatus concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-guide plate 11 End surface of a vertical direction 12 End surface of a horizontal direction 2 Vertical light source 3 Horizontal light source 10 Light guide plate type display apparatus

Claims (1)

A light source plate having a rectangular plane is provided, and a vertical light source and a horizontal light source are respectively disposed on the vertical end surface and the horizontal end surface of the light guide plate so that the emitted light can enter the light guide plate. A frame is formed around the light guide plate, the vertical light source and the horizontal light source are accommodated in the frame, and the vertical light source includes a plurality of LEDs spaced in the vertical direction; The horizontal light source is a cold cathode tube and / or a fluorescent tube, and a reflector is provided on the opposite side of the light introduction direction of the horizontal light source, and the vertical light source and the horizontal light source are in two directions. The light guide plate display device is characterized in that light is introduced into the light guide plate and uneven illumination caused by the vertically placed light source that is an LED is reduced by the horizontally placed light source .

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