JP5000423B2 - Still image display device - Google Patents

Description

  The present invention relates to a still image display device that is arranged on a transparent touch panel for operating a device and is used to project a still image such as a predetermined character on the touch panel.

  3 and 4 show the structure of a conventional still image display device. As shown in FIG. 3, the still image display device 90 includes a case 91 made of resin. The case 91 accommodates a background sheet 92, a light guide 93, and an attenuation sheet 94 in this order. The background sheet 92 has a uniformly small reflectance. The light guide 93 is made of a transparent material and has a lower surface on which a still image is provided. Specifically, the lower surface includes a rough surface region 93a and a smooth surface region 93b. The rough surface region 93a has irregularities formed by, for example, etching, and expresses a still image such as characters. On the other hand, the smooth surface region 93b has a smooth surface and serves as a background of the still image. The attenuation sheet 94 has a predetermined transmittance.

  The still image display device 90 further includes a light source including a light source circuit board 95 and an LED 96. The light source is provided on the end surface of the light guide 93.

  Next, the operation of the still image display device 90 will be described with reference to FIG. The LED 96 emits illumination light Ls. The illumination light Ls travels from the end surface of the light guide 93 to the inside of the light guide 93, and then propagates to the entire area inside the light guide 93 while being totally reflected by the upper and lower surfaces of the light guide 93. The illumination light Ls that has reached the rough surface region 93a is irregularly reflected. Thereby, a part of the illumination light Ls is transmitted through the attenuation sheet 94 and becomes strong emission light La. On the other hand, the illumination light Ls that has reached the smooth surface region 93b is not subjected to irregular reflection. For this reason, a very small part of the illumination light Ls passes through the attenuation sheet 94 and becomes weak emission light Lb. The contrast created by the strong outgoing light La and the weak outgoing light Lb allows the user to recognize a still image.

    Obviously, when the difference in intensity between the strong outgoing light La and the weak outgoing light Lb is small, recognition by the user becomes difficult. It cannot be said that the difference in intensity between the strong emitted light La and the weak emitted light Lb emitted from the still image display device 90 is sufficiently large. Therefore, the still image display device 90 has room for improvement in terms of ease of recognition of a still image by a user.

  Accordingly, an object of the present invention is to provide a still image display device that can display a still image that can be easily recognized by a user by emitting strong outgoing light La and weak outgoing light Lb having a large intensity difference. To do.

The still image display device provided by the present invention connects a light source, a first surface and a second surface opposite to the light source, and the first and second surfaces so that the light from the light source is opposed to the light source. A still image display device comprising: a flat, transparent light guide having an incident end surface ; and a background sheet provided on the second surface, wherein the second surface irregularly reflects light. The background sheet includes a high reflectivity region exhibiting high reflectivity and a low reflectivity region exhibiting low reflectivity. The rough surface area is disposed in the high reflectance region, the smooth surface region is disposed in the low reflectance region, and a still image is displayed by the rough surface region .

  Preferably, the high reflectivity region is white and the low reflectivity region is black.

  Preferably, the still image display device further includes an attenuation sheet provided on the first surface for attenuating light passing therethrough.

  1 and 2 show an embodiment of a still image display device according to the present invention. As shown in FIG. 1, the still image display device 10 includes a case 11 made of resin. The case 11 accommodates a background sheet 12, a light guide 13, and an attenuation sheet 14 in this order.

  The background sheet 12 characteristically includes a high reflectance region 12a and a low reflectance region 12b. The high reflectivity region 12a has a relatively high reflectivity and is typically white. On the other hand, the low reflectivity region 12b has a relatively low reflectivity and is typically black. The high reflectance region 12a and the low reflectance region 12b are provided at locations corresponding to a rough surface region 13a and a smooth surface region 13b, which will be described later, respectively.

  The light guide 13 is made of a transparent material and has a lower surface on which a still image is provided. Specifically, the lower surface includes a rough surface region 13a and a smooth surface region 13b. The rough surface area 13a has irregularities formed by, for example, etching, and expresses a still image such as characters. On the other hand, the smooth surface region 13b has a smooth surface and serves as a background of the still image.

  The attenuation sheet 14 has a relatively small predetermined transmittance. The attenuation sheet 14 is for preventing a user from seeing still images provided on the background sheet 12 and the light guide 13 when a light source to be described later is not turned on.

  The still image display device 10 further includes a light source including a light source circuit board 15 and LEDs 16. The light source is provided on the end face of the light guide 13.

  Next, the operation of the still image display device 10 will be described with reference to FIG. The LED 16 emits illumination light Ls. The illumination light Ls travels from the end face of the light guide 13 into the light guide 13 and then propagates to the entire area inside the light guide 13 while being totally reflected by the upper and lower surfaces of the light guide 13. The illumination light Ls that has reached the rough surface region 13a is irregularly reflected. Thereby, a part of the illumination light Ls is transmitted through the attenuation sheet 14 and becomes strong emission light La. At this time, the high reflectance region 12a provided under the rough surface region 13a reflects the illumination light Ls upward, thereby further increasing the intensity of the strong emitted light La.

  On the other hand, the illumination light Ls that has reached the smooth surface region 13b is not subjected to irregular reflection. Furthermore, the low reflectance region 12b provided below the smooth surface region 13b tends to absorb the illumination light Ls. For this reason, a very small part of the illumination light Ls is reflected upward. The reflected light loses most of its energy when passing through the attenuation sheet 14 having a relatively small transmittance. Thus, the reflected light becomes weak outgoing light Lb with negligible energy.

  According to the above configuration, the difference in intensity between the strong outgoing light La and the weak outgoing light Lb is large. Therefore, the contrast of the displayed still image is improved, and the user can easily recognize the still image displayed on the still image display device 10.

  The present invention is not limited to the embodiment described above. The specific configuration of each part of the present invention can be changed as appropriate. For example, the high reflectance region 12a only needs to satisfy the condition that the reflectance is relatively high, and may be silver or light yellow instead of white. The low reflectance region 12b only needs to satisfy the condition that the reflectance is relatively low, and may be dark blue or dark green instead of black.

It is a disassembled perspective view which shows the structure of the still image display apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the still image display apparatus which concerns on embodiment of this invention. It is a disassembled perspective view which shows the structure of the conventional still image display apparatus. It is sectional drawing which shows the structure of the conventional still image display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Still image display apparatus 11 Case 12 Background sheet 12a High reflectance area | region 12b Low reflectance area | region 13 Light guide 13a Rough surface area | region 13b Smooth surface area | region 14 Attenuation sheet 15 Light source circuit board 16 LED

Claims (3)

A light source;
A flat, transparent guide having a first surface and a second surface opposite to the first surface, and an end surface through which the light from the light source is incident by connecting the first and second surfaces and facing the light source. Light body,
A background sheet provided on the second surface;
A still image display device comprising:
The second surface includes a rough surface region for irregularly reflecting light, and a smooth surface region for transmitting or reflecting light,
The background sheet includes a high reflectance region exhibiting high reflectance, and a low reflectance region exhibiting low reflectance,
The rough surface region is disposed in the high reflectance region,
The smooth surface region is disposed in the low reflectance region ,
A still image display device in which a still image is displayed by the rough surface area .   The still image display device according to claim 1, wherein the high reflectance region is white and the low reflectance region is black.   The still image display device according to claim 1, further comprising an attenuation sheet provided on the first surface for attenuating light passing therethrough.

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