JP7050947B2 - Light guide for display - Google Patents

Description

The present invention relates to a light guide for a display used for detecting the illuminance of a display.

Conventionally, a display device that adjusts the display brightness according to the brightness of ambient light has been known. For example, the display device for a vehicle described in Patent Document 1 is installed in each of a light guide body for a display having one light input unit and two light guide units branched from the light input unit, and a light guide unit. It is equipped with a light receiving sensor. The ambient light on the driver's seat side is incident on one of the light guide sections from the light input section, and is guided to the light receiving sensor installed at the tip of the light guide section. The ambient light on the passenger seat side is incident on the other light guide section from the light input section, and is guided to the light receiving sensor installed at the tip of the light guide section. The display device adjusts the display brightness according to the brightness of the ambient light on the driver's seat side and the passenger seat side received by the two light receiving sensors, thereby improving the visibility of the screen display from the driver's seat side and the passenger seat side. Improve.

International Publication No. 2017/216958

Since the conventional light guide body for a display is configured as described above, there is a problem that a plurality of light receiving sensors are required to receive ambient light in a plurality of directions.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a light guide body for a display capable of guiding ambient light in a plurality of directions to one light receiving sensor. ..

The light guide body for a display according to the present invention has one light incoming surface on which light is incident and one light emitting surface which is arranged at a position facing the light receiving sensor and the emitted light is guided to the light receiving sensor. A display light guide body including a light guide portion that guides light incident on the incoming light surface to the light emitting surface, and the light guide portion has a central portion having a lower refractive index than the light guide portion. Light incident on the incoming surface from a second angle range between a first angle range having a small incident angle on the display surface and a third angle range having a large incident angle on the display surface is sent to the light emitting surface. The light is guided, and at least one of the light entering surface side and the light emitting surface side of the central portion reflects the light incident on the incoming light surface from the first angle range in a direction different from the light emitting surface after being incident on the light guide portion. It is a V-shaped or inclined reflecting surface, and on the light entering surface side of the outer surface of the light guide portion, the light incident on the light entering surface from the third angle range passes through the light guide portion and the light guide portion. The transmissive surface is a transmissive surface that transmits to the outside of the light, and the transmissive surface has an inclined shape in which the light inlet side protrudes most outward and approaches the central part as it goes toward the light exit surface. The length is longer than the width of the light incoming surface, which is the distance between one transmitting surface and the other transmitting surface in the light guide section.

According to the present invention, ambient light incident on the incoming light surface from a plurality of directions can be guided to one light receiving sensor installed on the light emitting surface of the light guide body for a display.

1A and 1B are overall views of the display device according to the first embodiment. 2A to 2C are three views of the display device according to the first embodiment. FIG. 3 is a cross-sectional view of the display device according to the first embodiment cut along the line AA of FIG. 2B. 4A and 4B are diagrams illustrating ambient light radiated to a display device installed in the center of the dashboard of a vehicle with a right-hand drive. It is a reference example for helping the understanding of the light guide body which concerns on Embodiment 1, and is the figure which shows the structure using two light guide bodies. It is another reference example for helping the understanding of the light guide body which concerns on Embodiment 1, and is the figure which shows the structure which used two light guide bodies. It is a perspective view of the light guide body which concerns on Embodiment 1. FIG. 8A to 8C are three views of the light guide body according to the first embodiment. It is a figure which shows the state which the light guide body which concerns on Embodiment 1 is installed in the display device. The angle formed by the direction perpendicular to the display surface shown in FIG. 9 and the horizontal component of the ambient light is θ, and the incident angle of the light reflected toward the viewpoint of the occupant sitting on the passenger seat side of the right-hand drive vehicle is +30 degrees. It is a graph which shows the detection characteristic of the light receiving sensor when the incident angle of the light reflected in the viewpoint direction of the occupant sitting on the driver's seat side is set to -30 degrees. 11A and 11B are views showing a modified example of the light guide body according to the first embodiment. It is a figure which shows the state which the light guide body which concerns on Embodiment 2 is installed in the display device. It is a figure which shows the state which the light guide body which concerns on Embodiment 3 is installed in the display device. 14A is a diagram showing a state in which the light guide body according to the fourth embodiment is installed in the display device, and FIG. 14B is a side view thereof. 15A and 15B are enlarged views of the F region in FIG. 14A. 16A is a diagram showing a state in which the light guide body according to the fifth embodiment is installed in the display device, and FIG. 16B is a cross-sectional view taken along the line GG of FIG. 16A. It is a figure which shows the modification of the light guide body which concerns on Embodiment 5.

Hereinafter, in order to explain the present invention in more detail, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.
Embodiment 1.
1A and 1B are overall views of the display device 10 according to the first embodiment. 2A to 2C are three views of the display device 10 according to the first embodiment. FIG. 3 is a cross-sectional view of the display device 10 according to the first embodiment cut along the line AA of FIG. 2B.

The display device 10 is, for example, a display of a car navigation device installed on the dashboard of a vehicle, and the display screen is visually recognized mainly from two directions, the driver's seat side and the passenger seat side. In the display device 10, the liquid crystal module 1 for displaying an image is housed in a housing 7. The display screen of the liquid crystal module 1 is covered with a cover 2 which is made of a transparent material such as glass or resin and functions as a design. Further, the printed circuit board 6 for realizing the function of adjusting the brightness of the liquid crystal module 1 is housed in the housing 7. One light receiving sensor 5 is mounted on the printed circuit board 6. Further, the light guide body 3c for guiding the ambient light on the driver's seat side and the ambient light on the passenger seat side to one light receiving sensor 5 is held at a position facing the light receiving sensor 5 by the holding member 4. .. In the first embodiment, an example is shown in which the light guide body 3c is held on the printed circuit board 6 by a holding member 4 integrally configured with the light guide body 3c, but the holding means of the light guide body 3c is a holding member. Not limited to 4.

4A and 4B are diagrams illustrating ambient lights 11A to 11C radiated to a display device 10 installed in the center of the dashboard of a vehicle with a right-hand drive. Note that FIG. 4A shows a cross section of the display device 10 cut along the line BB of FIG. 2B. The display surface 2a is the back surface of the cover 2 and is also the display screen of the liquid crystal module 1. Of the ambient light incident on the display surface 2a, the ambient light incident from the direction perpendicular to the display surface 2a and reflected in the vertical direction is referred to as ambient light 11A. Further, the ambient light 11B is defined as the ambient light that is incident on the display surface 2a at an incident angle α1 and is reflected by the display surface 2a toward the viewpoint of the occupant sitting in the driver's seat. Further, the ambient light 11C is defined as the ambient light that is incident on the display surface 2a from the direction opposite to the ambient light 11B at an incident angle β1 and is reflected by the display surface 2a toward the viewpoint of the occupant sitting in the passenger seat. The incident angle α1 is an angle formed by a direction perpendicular to the display surface 2a and a direction in which the ambient light 11B is incident on the display surface 2a. The incident angle β1 is an angle formed by a direction perpendicular to the display surface 2a and a direction in which the ambient light 11C is incident on the display surface 2a.

As shown in FIG. 4B, the direction perpendicular to the display surface 2a is 0 degree. Then, the angle range from 0 degree to the incident angle θ1 (θ1> 0) is set as the first angle range, and the angle range from the incident angle θ1 to the incident angle θ2 (θ2> θ1) is set as the second angle range. The angle range from the angle θ2 to the incident angle θ3 is defined as the third angle range. The incident angle θ3 is 90 degrees and is parallel to the display surface 2a. The above-mentioned incident angle β1 is within the second angle range from the incident angle θ1 to the incident angle θ2. In other words, the incident angles θ1 and θ2 are defined by the positional relationship between the display device 10 and the passenger seat.

Further, the angle range from 0 degree to the incident angle −θ1 (−θ1 <0) is the first angle range, and the angle range from the incident angle −θ1 to the incident angle −θ2 (−θ2 ＜ −θ1) is the second. The angle range from the incident angle −θ2 to the incident angle −θ3 is defined as the third angle range. The incident angle −θ3 is −90 degrees and is parallel to the display surface 2a. The above-mentioned incident angle α1 is within the second angle range from the incident angle −θ1 to the incident angle −θ2. In other words, the incident angles −θ1 and −θ2 are defined by the positional relationship between the display device 10 and the driver's seat.

When the surroundings are too dark with respect to the brightness of the display screen of the display device 10, there is a problem that the image displayed on the display device 10 is dazzling and difficult to see. Further, when the display screen of the display device 10 is brighter than an appropriate brightness, there is a problem that the power consumption of the display device 10 cannot be suppressed. On the contrary, when the surroundings are too bright with respect to the brightness of the display screen of the display device 10, there is a problem that it is difficult for the occupant to recognize the image because the light reflected by the display device 10 enters the occupant's eyes.

Here, as a reference example for assisting the understanding of the light guide body 3c according to the first embodiment, FIG. 5 shows a configuration using two light guide bodies 3a1 and 3a2. In the reference example of FIG. 5, in the region of the cover 2 that does not overlap with the liquid crystal module 1, the printed portion 2b on which the material that does not transmit light is printed and the material that does not transmit light are not printed and are transparent or transparent. There is a non-printing portion 2c having semi-transparency. As a matter of course, the material that does not transmit light is not printed in the region of the cover 2 that overlaps with the liquid crystal module 1. In the non-printing unit 2c, the light input surfaces 3a1-1,3a2-1 of the light guide bodies 3a1, 3a2 are arranged. Light receiving sensors 5-1 and 5-2 are arranged on the light emitting surfaces 3a1-3 and 3a2-3 of the light guide bodies 3a1 and 3a2, respectively.

A part of the ambient light 11C reflected toward the viewpoint of the passenger sitting in the passenger seat passes through the non-printing portion 2c and is incident on the light entering surface 3a1-1 of the light guide body 3a1 and is incident on the inner surface of the light guide portion 3a1-2. After repeating the reflection at the light emitting surface 3a1-3, the light is emitted from the light guide body 3a1 to the outside. The light receiving sensor 5-1 mounted on the printed circuit board 6 receives the ambient light C11 emitted from the light emitting surface 3a1-3 and outputs an electric signal indicating the brightness of the ambient light 11C. Similarly, a part of the ambient light 11B reflected toward the viewpoint of the occupant sitting in the driver's seat is guided to the light receiving sensor 5-2 by the light guide body 3a2, and the light receiving sensor 5-2 has the brightness of the ambient light 11B. Outputs an electric signal representing. The electrical signals output by the light receiving sensors 5-1 and 5-2 are processed by integrated circuits and software (not shown), and as a result, the backlight built into the liquid crystal module 1 is visible to both the driver and passenger seat occupants. The brightness is adjusted so that it is easy to use.

Further, among the ambient light incident on the light entrance surface 3a1-1 of the light guide body 3a1, the ambient light incident from the first angle range and the third angle range that are not reflected in the viewpoint direction of the passenger sitting in the passenger seat is included in the ambient light. By repeating reflection or refraction at the interface with the substance (for example, air) adjacent to the light guide body 3a1, the light guide to the light receiving sensor 5-1 is suppressed. Similarly, among the ambient light incident on the light entrance surface 3a2-1 of the light guide body 3a2, the ambient light incident from the first angle range and the third angle range that are not reflected toward the viewpoint of the occupant sitting in the driver's seat By repeating reflection or refraction at the interface with the substance (for example, air) adjacent to the light guide body 3a2, the light guide to the light receiving sensor 5-2 is suppressed.

In the reference example of FIG. 5, two light receiving sensors 5-1 and 5-2 are required for each of the light guide bodies 3a1 and 3a2, for a total of two, so that the component cost is high and these components are arranged. Space was needed.

FIG. 6 is another reference example for assisting the understanding of the light guide body 3c according to the first embodiment, and is a diagram showing a configuration using two light guide bodies 3b1 and 3b2. In the reference example of FIG. 6, in order to arrange one light receiving sensor 5 for two light guide bodies 3b1 and 3b2, the light guide distance from the light entry surface to the light emission surface of the light guide bodies 3b1 and 3b2 is guided. It was necessary to make it longer than the bodies 3a1 and 3a2. Therefore, a larger space was required to arrange the light guide bodies 3b1 and 3b2.
As shown by the two-dot chain line in FIG. 6, it is also conceivable to reduce the radius of curvature of the light guide bodies 3b1, 3b2 without increasing the light guide distance of the light guide bodies 3b1, 3b2. However, in the case of this configuration, the luminous flux that can be guided to the light receiving sensor 5 is reduced, so that the sensitivity of the light receiving sensor 5 deteriorates.

Therefore, in the first embodiment, the light receiving sensor 5 is integrated into one to reduce the component cost, and the light guide distance of the light guide body 3c is not lengthened to maintain space saving.
FIG. 7 is a perspective view of the light guide body 3c according to the first embodiment. 8A to 8C are three views of the light guide body 3c according to the first embodiment. FIG. 9 is a diagram showing a state in which the light guide body 3c according to the first embodiment is installed in the display device 10. As described above, the ambient light 11C is the ambient light incident from the second angle range of the ambient light incident on the light entry surface 3c-1 of the light guide body 3c, which is reflected toward the viewpoint of the occupant sitting in the passenger seat. Is. On the other hand, among the ambient light incident on the light entrance surface 3c-1 of the light guide body 3c, the ambient light incident from the first angle range that does not reflect toward the viewpoint of the passenger sitting in the passenger seat is defined as the ambient light 11D. Similarly, the ambient light 11E is the ambient light incident from a third angle range that does not reflect toward the viewpoint of the occupant sitting in the passenger seat.

The light guide body 3c mainly includes an incoming light surface 3c-1 to which the ambient light 11C, 11D, 11E is incident, and an emitted light surface 3c-3 to which the ambient light 11C of the ambient light 11C, 11D, 11E is emitted. It is provided with a light guide unit 3c-2 that guides the ambient light 11C among the ambient lights 11C, 11D, and 11E incident on the incoming light surface 3c-1 to the outgoing light surface 3c-3. The holding member 4 is integrally configured in the light guide body 3c. The holding member 4 includes an engaging claw 4a that engages with an engaging hole formed in the printed circuit board 6, a columnar boss 4b that fits into a round hole formed in the printed circuit board 6, and a printed circuit board 6. It is provided with a contact portion 4c that abuts on one side. The holding member 4 holds the light guide body 3c on the printed circuit board 6 by attaching to the printed circuit board 6. As a result, the light entry surface 3c-1 is arranged at a position facing the non-printing portion 2c of the cover 2. The light emitting surface 3c-3 is arranged at a position facing the light receiving sensor 5 mounted on the printed circuit board 6.

The light guide portion 3c-2 has a central portion 3c-6 in the central portion thereof, which is made of a substance having a refractive index different from that of the light guide portion 3c-2. The slit-shaped central portion 3c-6 divides the light guide portion 3c-2 into the driver's seat side and the passenger seat side, so that the light guide path from the light entry surface 3c-1 to the light exit surface 3c-3 is also two paths. become. One light guide path is a path for guiding the ambient light 11C to the light receiving sensor 5, and the other path is a path for guiding the ambient light 11B (not shown) to the light receiving sensor 5. When the light guide portion 3c-2 is made of a transparent material such as glass or resin, the central portion 3c-6 is air or the like. Further, the light guide portion 3c-2 may be solid or hollow.

Here, the substance constituting the light guide section 3c-2 is a transparent resin, the substance existing outside the light guide section 3c-2 is air having a refractive index smaller than that of the resin, and the substance constituting the central portion 3c-6. Assuming that is air, the light incident on the air from the transparent resin or the light incident on the transparent resin from the air has a large proportion of the transmitted light when the incident angle is small, and the incident angle is large, according to Frenel's equation. It is clear that the proportion of reflected light increases.

The central portion 3c-6 has a V-shaped reflecting surface 3c-5 on the light entering surface 3c-1 side, and also has a V-shaped reflecting surface 3c-5 on the light emitting surface 3c-3 side. The reflective surface 3c-5 has a direction different from that of the light emitting surface 3c-3 after the ambient light 11D incident on the incoming light surface 3c-1 from the first angle range where the incident angle is small is incident on the light guide unit 3c-2. Reflect to. The direction different from the light emitting surface 3c-3 is a direction toward the outside of the light guide unit 3c-2, such as the direction of the transmitting surface 3c-4 described later.

The light entrance surface 3c-1 side of the outer surface of the light guide unit 3c-2 is the transmission surface 3c-4. The transmission surface 3c-4 is outside the light guide unit 3c-2 as it is after the ambient light 11E incident on the light entrance surface 3c-1 from the third angle range having a large incident angle is incident on the light guide unit 3c-2. Make it transparent to. In the light guide body 3c of the first embodiment, the transmission surface 3c-4 has an inclined shape in which the light entry surface 3c-1 side protrudes most to the outside and approaches the central portion 3c-6 as the light exit surface 3c-3 is approached. ..

Here, the light guide paths of the ambient lights 11C, 11D, and 11E in the light guide body 3c will be described.
The ambient light 11D incident on the light entering surface 3c-1 from the first angle range that does not reflect in the viewpoint direction of the occupant enters the light guide unit 3c-2 from the light entrance surface 3c-1 and becomes the light guide unit 3c-2. Most of them are reflected by the reflecting surfaces 3c-5 having different refractive indexes and head toward the transmitting surface 3c-4. Most of the ambient light 11D directed to the transmission surface 3c-4 is incident on the transmission surface 3c-4 at a small incident angle, so that the ambient light 11D passes through the transmission surface 3c-4 and is emitted to the outside of the light guide unit 3c-2. Therefore, most of the ambient light 11D does not reach the emission surface 3c-3.

The ambient light 11E incident on the incoming light surface 3c-1 from the third angle range that does not reflect toward the viewpoint of the occupant enters the light guide portion 3c-2 from the incoming light surface 3c-1, and most of them enter the light guide portion 3c-2 as they are. Head to -4. Most of the ambient light 11E directed to the transmission surface 3c-4 is incident on the transmission surface 3c-4 at a small incident angle, so that the ambient light 11E passes through the transmission surface 3c-4 and is emitted to the outside of the light guide unit 3c-2. Therefore, most of the ambient light 11E does not reach the emission surface 3c-3.

The ambient light 11C incident on the light entering surface 3c-1 from the second angle range reflected toward the viewpoint of the occupant enters the light guide unit 3c-2 from the light entrance surface 3c-1 and enters the light guide unit 3c-2. It reflects on the inner surface and reaches the light emitting surface 3c-3. The ambient light 11C that has reached the light emitting surface 3c-3 is emitted from the light emitting surface 3c-3 and received by the light receiving sensor 5.

In FIG. 10, the angle formed by the direction perpendicular to the display surface 2a shown in FIG. 9 and the horizontal component of the ambient light is θ, and the ambient light reflected toward the viewpoint of the occupant sitting on the passenger seat side of the right-hand drive vehicle. 6 is a graph showing the detection characteristics of the light receiving sensor 5 when the incident angle β1 is set to +30 degrees and the incident angle α1 reflected in the viewpoint direction of the occupant sitting on the driver's seat side is set to −30 degrees. The detection characteristic of the light receiving sensor 5 on the vertical axis is the horizontal detection sensitivity when the maximum value is 100%. In the example of FIG. 10, the incident angle β1 reflected by the ambient light 11C toward the viewpoint of the passenger sitting in the passenger seat is 30 degrees, the incident angle θ1 is 25 degrees, the incident angle θ2 is 40 degrees, and the incident angle θ3 is 90 degrees. Degree. Further, the incident angle α1 that the ambient light 11B reflects toward the viewpoint of the occupant sitting in the driver's seat is -30 degrees, the incident angle −θ1 is -25 degrees, the incident angle −θ2 is −40 degrees, and the incident angle −θ3. Is -90 degrees. From the graph, it can be confirmed that the light receiving sensor 5 selectively receives the ambient light 11C toward the viewpoint of the occupant sitting in the passenger seat and the ambient light 11B toward the viewpoint of the occupant sitting in the driver's seat.
The incident angles ± θ1, ± θ2, ± θ3 can be changed by changing the angles and positions of the reflecting surface 3c-5 and the transmitting surface 3c-4 in the light guide body 3c. Therefore, it is possible to shorten the light guide distance of the light guide body 3c.

From the above, the light guide body 3c according to the first embodiment includes an incoming light incoming surface 3c-1, an outgoing light emitting surface 3c-3, and a light guide unit 3c-2. The light guide unit 3c-2 has a light incoming surface 3c from a second angle range between a first angle range in which the incident angle with respect to the display surface 2a is small and a third angle range in which the incident angle with respect to the display surface 2a is large. The ambient light 11C incident on -1 is guided to the light emitting surface 3c-3. The light guide portion 3c-2 has a central portion 3c-6 whose central portion is made of a substance having a refractive index different from that of the light guide portion 3c-2. On the incoming light surface 3c-1 side and the light emitting surface 3c-3 side of the central portion 3c-6, the ambient light 11D incident on the incoming light surface 3c-1 from the first angle range was incident on the light guide portion 3c-2. It is a V-shaped reflecting surface 3c-5 that later reflects in a direction different from that of the light emitting surface 3c-3. Further, on the light inlet surface 3c-1 side of the outer surface of the light guide unit 3c-2, the ambient light 11E incident on the light input surface 3c-1 from the second angle range passes through the light guide unit 3c-2. It is a transmission surface 3c-4 that is transmitted to the outside of the light guide unit 3c-2. The reflective surface 3c-5 and the transmissive surface 3c-4 can suppress the light guidance of the ambient light 11D and 11E that are not reflected in the occupant's viewpoint direction to the light receiving sensor 5, and select the ambient light 11C that is reflected in the occupant's viewpoint direction. The light can be guided to the light receiving sensor 5. Therefore, the light guide body 3c receives the ambient light 11B incident on the incoming light surface 3c-1 from the second angle range on the driver's seat side to one light receiving sensor 5 installed on the light emitting surface 3c-3. The ambient light 11C incident on the incoming light surface 3c-1 can be guided from the second angle range on the passenger side. As a result, the display device 10 can improve the visibility of the display screen based on the ambient lights 11B and 11C received by the light receiving sensor 5. Further, since the light guide body 3c for guiding the ambient light 11B and 11C can be integrated into one, the light guide distance of the light guide body 3c can be shortened, and the light receiving sensor 5 can be integrated into one. , Cost reduction and space saving. Further, since the light input surface 3c-1 that captures the ambient light 11B and 11C can be unified, the non-printing portion 2c of the cover 2 is smaller than the case where two light input surfaces are provided as shown in FIG. This can improve the design of the display device 10.

Further, the transmission surface 3c-4 of the light guide body 3c according to the first embodiment has an inclined shape in which the light entry surface 3c-1 side projects most outward and the light emission surface 3c-3 approaches the central portion 3c-6. be. Since the transmission surface 3c-4 has an inclined shape, the incident angle when light enters the transmission surface 3c-4 is smaller than that when the transmission surface 3c-4 is a plane perpendicular to the display surface 2a. Become. Therefore, the proportion of light transmitted through the inclined transmission surface 3c-4 and emitted to the outside is larger than that in the case where the transmission surface 3c-4 is a plane perpendicular to the display surface 2a. Therefore, the light guide body 3c can suppress the light guide to the light receiving sensor 5 of the ambient light 11D and 11E that are not reflected in the viewpoint direction of the occupant, and preferentially directs the ambient light 11C reflected in the viewpoint direction of the occupant to the light receiving sensor 5. It can guide light.

Further, in the first embodiment, when the substance having a refractive index different from that of the light guide portion 3c-2 constituting the central portion 3c-6 is air, the light guide body 3c is made of one kind of material such as glass or resin. Since it can be manufactured with, the manufacturing cost can be reduced.

In the first embodiment, the central portion 3c-6 has a V-shaped reflecting surface 3c-5 on the light entering surface 3c-1 side, and also has a V-shaped reflecting surface on the light emitting surface 3c-3 side. It was a configuration having 3c-5, but is not limited to this configuration. Here, FIGS. 11A and 11B show modified examples of the light guide body 3c according to the first embodiment. In the modified example of FIG. 11A, the central portion 3c-6 has a reflecting surface 3c-5 only on the light entering surface 3c-1 side, and the light emitting surface 3c-3 side is a flat surface 3c-7. In the modified example of FIG. 11B, the central portion 3c-6 has a reflecting surface 3c-5 only on the light emitting surface 3c-3 side, and the light entering surface 3c-1 side is a flat surface 3c-8. In the modified example of FIG. 11B, since there is no reflecting surface 3c-5 on the light entering surface 3c-1 side of the central portion 3c-6, the ambient light 11D passes through the flat surface 3c-8 and completely covers the inside of the central portion 3c-6. It reflects and proceeds, is reflected or transmitted by the reflecting surface 3c-5 on the light emitting surface 3c-3 side, heads in a direction different from that of the light emitting surface 3c-3, and is emitted to the outside of the light guide unit 3c-2. Therefore, even in the case of the configuration shown in FIGS. 11A and 11B, the light guide body 3c can suppress the light guide to the light receiving sensor 5 of the ambient light 11D and 11E that are not reflected in the viewpoint direction of the occupant, and the viewpoint direction of the occupant. The ambient light 11C reflected to the light can be guided to the light receiving sensor 5 with higher priority.

Embodiment 2.
FIG. 12 is a diagram showing a state in which the light guide body 3d according to the second embodiment is installed in the display device 10. In FIG. 12, parts that are the same as or correspond to those in FIGS. 7 to 9 are designated by the same reference numerals and description thereof will be omitted. The light guide body 3d includes a light input surface 3c-1, a light guide unit 3c-2, a light emission surface 3c-3, a transmission surface 3c-4, a reflection surface 3c-5, and a center in the light guide body 3c of the first embodiment. It is provided with a light incoming surface 3d-1, a light guide unit 3d-2, a light emitting surface 3d-3, a transmitting surface 3d-4, a reflecting surface 3d-5, and a central portion 3d-6, which correspond to the unit 3c-6.
Further, since the configuration of the display device 10 according to the second embodiment is the same as the configuration shown in FIGS. 1 to 4 of the first embodiment on the drawing, FIGS. 1 to 4 will be referred to below.

In the light guide body 3c of the first embodiment, the transmission surface 3c-4 has an inclined shape, but in the light guide body 3d of the second embodiment, the transmission surface 3d-4 has an arc shape in which the transmission surface 3d-4 bulges outward. Most of the ambient light 11D and 11E incident on the incoming light surface 3d-1 from the first angle range and the third angle range that do not reflect in the viewpoint direction of the occupant pass through the arc-shaped transmitting surface 3d-4. It emits light to the outside of the light guide unit 3d-2. At this time, since the transmission surface 3d-4 has an arc shape, the incident angle when light enters the transmission surface 3d-4 is smaller than that of the inclined transmission surface 3c-4. Therefore, the proportion of light transmitted through the arc-shaped transmitting surface 3d-4 and emitted to the outside is larger than that of the inclined-shaped transmitting surface 3c-4. Therefore, the light guide body 3d can suppress the light guide to the light receiving sensor 5 of the ambient light 11D and 11E that are not reflected in the viewpoint direction of the occupant, and the ambient light 11C reflected in the viewpoint direction of the occupant can be given priority to the light receiving sensor 5. Can be guided to.

Embodiment 3.
FIG. 13 is a diagram showing a state in which the light guide body 3e according to the third embodiment is installed in the display device 10. In FIG. 13, the same or corresponding parts as those in FIGS. 7 to 9 are designated by the same reference numerals and the description thereof will be omitted. The light guide body 3e includes a light input surface 3c-1, a light guide unit 3c-2, a light emission surface 3c-3, a transmission surface 3c-4, a reflection surface 3c-5, and a center in the light guide body 3c of the first embodiment. It is provided with a light incoming surface 3e-1, a light guide unit 3e-2, a light emitting surface 3e-3, a transmitting surface 3e-4, a reflecting surface 3e-5, and a central portion 3e-6, which correspond to the unit 3c-6.
Further, since the configuration of the display device 10 according to the third embodiment is the same as the configuration shown in FIGS. 1 to 4 of the first embodiment on the drawing, FIGS. 1 to 4 will be referred to below.

In the light guide body 3c of the first embodiment, the transmission surface 3c-4 has an inclined shape, but the light guide body 3e of the third embodiment has a rectangular shape in which the transmission surface 3e-4 bulges outward. The transmission surface 3e-4 is composed of an inclined portion 3e-4a and a straight portion 3e-4b. The inclined portion 3e-4a has an inclined shape that protrudes outward from the incoming light surface 3e-1 toward the outgoing light surface 3e-3. The straight portion 3e-4b has a linear shape extending in a direction parallel to the display surface 2a, connecting the light emitting surface 3e-3 side end portion of the inclined portion 3e-4a and the light guide portion 3e-2. Most of the ambient light 11D and 11E incident on the incoming light surface 3e-1 from the first angle range and the third angle range that do not reflect in the viewpoint direction of the occupant are the linear portions 3e-4b of the transmission surface 3e-4. It transmits and emits light to the outside of the light guide unit 3e-2. However, a part of the ambient light 11D and 11E incident on the straight line portion 3e-4b does not pass through the straight line portion 3e-4b but is reflected by the straight line portion 3e-4b. The ambient lights 11D and 11E reflected by the straight line portion 3e-4b are incident on the inclined portion 3e-4a with a small incident angle, and most of them pass through the inclined portion 3e-4a and are emitted to the outside. In this way, since the inclined portion 3e-4a is arranged so that the incident angle of the light reflected by the straight portion 3e-4b becomes small, most of the ambient light 11D and 11E pass through the transmission surface 3e-4. The light is emitted to the outside of the light guide unit 3e-2. Therefore, the light guide body 3e can suppress the light guide to the light receiving sensor 5 of the ambient light 11D and 11E that is not reflected in the viewpoint direction of the occupant, and preferentially directs the ambient light 11C reflected in the viewpoint direction of the occupant to the light receiving sensor 5. It can guide light.

The shape of the transparent surface 3e-4 is not limited to the rectangular shape shown in FIG. The shape of the transmission surface 3e-4 is such that the ambient light 11D and 11E, which are not reflected toward the viewpoint of the occupant, are intentionally reflected multiple times so as to be difficult to reach the light receiving sensor 5, and finally the incident surface becomes smaller. It may be a shape that allows the light to pass through and is emitted to the outside.

Embodiment 4.
14A is a diagram showing a state in which the light guide body 3f according to the fourth embodiment is installed in the display device 10, and FIG. 14B is a side view thereof. In FIGS. 14A and 14B, the same or corresponding parts as those in FIGS. 7 to 9 are designated by the same reference numerals and the description thereof will be omitted. The light guide body 3f includes a light input surface 3c-1, a light guide unit 3c-2, a light emission surface 3c-3, a transmission surface 3c-4, a reflection surface 3c-5, and a center in the light guide body 3c of the first embodiment. It is provided with a light incoming surface 3f-1, a light guide unit 3f-2, a light emitting surface 3f-3, a transmitting surface 3f-4, a reflecting surface 3f-5, and a central portion 3f-6, which correspond to the unit 3c-6.
Further, since the configuration of the display device 10 according to the second embodiment is the same as the configuration shown in FIGS. 1 to 4 of the first embodiment on the drawing, FIGS. 1 to 4 will be referred to below.

In the light guide body 3c of the first embodiment, the transmission surface 3c-4 has an inclined shape, but in the light guide body 3f of the fourth embodiment, the transmission surface 3f-4 has a shape perpendicular to the display surface 2a. .. Therefore, the outer shape of the light guide body 3f is smaller than that of the light guide body 3c, which saves more space.

Further, the transmission surface 3f-4 is not a flat surface but an uneven surface. 15A and 15B are enlarged views of the F region in FIG. 14A. In the example of FIG. 15A, the uneven surface of the transmission surface 3f-4 is configured by continuously arranging fine planes. As shown in FIG. 15B, the unevenness of the transmission surface 3f-4 may have a smooth wave shape. Further, although not shown, the transmission surface 3f-4 may be a textured surface. As described above, since the transmission surface 3f-4 is an uneven surface, the incident angle when light enters the transmission surface 3f-4 is smaller than that of a flat surface. Therefore, the ratio of the ambient light 11D and 11E transmitted to the outside through the transmission surface 3f-4, which is an uneven surface, is larger than that of the flat surface. Therefore, the light guide body 3f can suppress the light guide to the light receiving sensor 5 of the ambient light 11D and 11E that are not reflected in the viewpoint direction of the occupant, and the ambient light 11C reflected in the viewpoint direction of the occupant can be given higher priority to the light receiving sensor 5. Can be guided to.

The transmission surface 3c-4 of the light guide body 3c according to the first embodiment may be an uneven surface as in the fourth embodiment. Similarly, the transmission surface 3d-4 of the light guide body 3d according to the second embodiment and the transmission surface 3e-4 of the light guide body 3e according to the third embodiment become uneven surfaces as in the fourth embodiment. You may be. By combining the configurations of the fourth embodiment with the configurations of the first to third embodiments, the ambient light 11C reflected in the viewpoint direction of the occupant can be guided to the light receiving sensor 5 with higher priority.

Embodiment 5.
FIG. 16A is a diagram showing a state in which the light guide body 3g according to the fifth embodiment is installed in the display device 10. FIG. 16B is a cross-sectional view taken along the line GG of FIG. 16A. In FIGS. 16A and 16B, the same or corresponding parts as those in FIGS. 7 to 9 are designated by the same reference numerals, and the description thereof will be omitted. The light guide body 3g includes a light input surface 3c-1, a light guide unit 3c-2, a light emission surface 3c-3, a transmission surface 3c-4, a reflection surface 3c-5, and a center in the light guide body 3c of the first embodiment. It is provided with a light incoming surface 3g-1, a light guide unit 3g-2, a light emitting surface 3g-3, a transmitting surface 3g-4, a reflecting surface 3g-5, and a central portion 3g-6, which correspond to the portion 3c-6.
Further, since the configuration of the display device 10 according to the third embodiment is the same as the configuration shown in FIGS. 1 to 4 of the first embodiment on the drawing, FIGS. 1 to 4 will be referred to below.

The light guide body 3c of the first embodiment has a configuration in which a V-shaped reflecting surface 3c-5 is provided on each of the light entering surface 3c-1 side and the light emitting surface 3c-3 side of the central portion 3c-6. The light guide body 3g of the sixth embodiment has a V-shaped reflecting surface 3g-5 on the light emitting surface 3g-3 side of the central portion 3g-6, and an inclined reflecting surface on the light entering surface 3g-1 side. It has a structure having a surface of 3 g-7. As shown in FIG. 16B, the reflecting surface 3g-7 is composed of two inclined surfaces so as to have a V-shaped cross section.

The ambient light 11D incident on the incoming light surface 3g-1 from the first angle range that is not reflected toward the viewpoint of the occupant enters the light guide portion 3g-2 from the incoming light surface 3g-1, and is reflected by the reflecting surface 3g-7. Most of them are reflected or refracted and go in a direction different from the light emitting surface 3g-3. The ambient light 11D directed in a direction different from the light emitting surface 3g-3 is emitted to the outside of the light guide unit 3g-2. Therefore, the light guide body 3g can suppress the light guide to the light receiving sensor 5 of the ambient light 11D and 11E that are not reflected in the viewpoint direction of the occupant, and preferentially direct the ambient light 11C reflected in the viewpoint direction of the occupant to the light receiving sensor 5. It can guide light.

The reflective surface 3g-7 may be composed of two inclined surfaces so that the cross section is V-shaped as shown in FIG. 16B, or may be composed of only one of the two inclined surfaces. good. Further, the reflecting surface 3g-7 may be provided on the light emitting surface 3g-3 side of the central portion 3g-6, or on the light entering surface 3g-1 side and the light emitting surface 3g-3 side of the central portion 3g-6. It may be provided for each.
Further, the inclined reflecting surface 3g-8 as illustrated in FIG. 17 may be provided on each of the incoming surface 3g-1 side and the light emitting surface 3g-3 side of the central portion 3g-6. FIG. 17 is a diagram showing a modified example of the light guide body 3g according to the fifth embodiment. Further, the reflecting surface 3g-8 may be provided on either the incoming surface 3g-1 side or the light emitting surface 3g-3 side of the central portion 3g-6. When there is no reflecting surface 3g-7 and reflecting surface 3g-8 on the light entering surface 3g-1 side of the central portion 3g-6, the ambient light 11D is incident on the light entering surface 3g-1 and then the light guide portion 3g. It passes through the boundary between -2 and the central part 3g-6, completely reflects inside the central part 3g-6, and is reflected or transmitted by the reflective surface 3g-8 on the light emitting surface 3g-3 side, and the light emitting surface 3g- The light is emitted to the outside of the light guide unit 3g-2 in a direction different from that of 3.
As described above, the reflecting surface 3g-7, 3g-8 may have an inclined shape that reflects or refracts the ambient light 11D so as to be directed in a direction different from that of the light emitting surface 3g-3.

Further, the reflecting surface 3g-7 or the reflecting surface 3g-8 as in the fifth embodiment may be provided in the central portion 3d-6 of the light guide body 3d according to the second embodiment. Similarly, the central portion 3e-6 of the light guide body 3e according to the third embodiment and the central portion 3e-6 of the light guide body 3f according to the fourth embodiment have a reflective surface 3g- as in the fifth embodiment. 7 or a reflective surface 3g-8 may be provided.
Further, the transmission surfaces 3c-4 to 3g-4 of the light guide bodies 3c to 3g provided with the reflection surface 3g-7 or the reflection surface 3g-8 are uneven surfaces such as the transmission surface 3f-4 of the fourth embodiment. It may be.

The present invention allows any combination of embodiments, modifications of any component of each embodiment, or omission of any component of each embodiment within the scope of the invention.

The light guide for display according to the present invention can improve the visibility of the screen display from a plurality of directions. Therefore, for example, a display device for a vehicle in which the screen display can be visually recognized from the direction of each seat of the vehicle. Suitable for use.

1 Liquid crystal module, 2 cover, 2a display surface, 2b printing unit, 2c non-printing unit, 3a1, 3a2, 3b1, 3b2 light guide body, 3a1-1,3a2-1 light input surface, 3a1-2, 3a2-2 guide Optical part, 3a1-3, 3a2-3 Emission surface, 3c, 3d, 3e, 3f, 3g Light guide body (light guide body for display), 3c-1, 3d-1, 3e-1, 3f-1, 3g -1 Light entrance surface, 3c-2, 3d-2, 3e-2, 3f-2, 3g-2 Light guide unit, 3c-3, 3d-3, 3e-3, 3f-3, 3g-3 Light emission surface , 3c-4, 3d-4, 3e-4, 3f-4, 3g-4 Permeation surface, 3c-5, 3d-5, 3e-5, 3f-5, 3g-5, 3g-7,3g-8 Reflective surface, 3c-6,3d-6,3e-6,3f-6,3g-6 Central part, 3c-7,3c-8 plane, 3e-4a inclined part, 3e-4b straight part, 4 holding member, 4a Engagement claw, 4b boss, 4c contact part, 5,5-1,5-2 light receiving sensor, 6 printed circuit board, 7 housing, 10 display device, 11A-11E ambient light, α1, β1, ± θ1 , ± θ 2, ± θ 3 Incident angle.

Claims (3)

One light entering surface on which light is incident, one light emitting surface that is arranged at a position facing the light receiving sensor and the emitted light is guided to the light receiving sensor, and light incident on the light receiving surface. A light guide body for a display including a light guide unit that guides light to the light emitting surface.
The light guide portion has a central portion having a central portion having a lower refractive index than the light guide portion, a first angle range in which the incident angle with respect to the display surface is small, and a third angle in which the incident angle with respect to the display surface is large. The light incident on the incoming surface from the second angle range between the ranges is guided to the outgoing surface.
At least one of the incoming surface side and the outgoing surface side of the central portion is in a direction different from the outgoing surface after the light incident on the incoming surface from the first angle range is incident on the light guide portion. It is a V-shaped or inclined reflecting surface that reflects to
On the light entrance surface side of the outer surface of the light guide portion, light incident on the light entrance surface from the third angle range passes through the light guide portion and is transmitted to the outside of the light guide portion. Is a face
The transmissive surface has an inclined shape in which the light entry surface side protrudes most outward and approaches the central portion as it approaches the light emission surface.
The length of the central portion from the incoming surface side to the outgoing surface side is the width of the incoming surface, which is the distance between the one transmitting surface and the other transmitting surface in the light guide portion. A light guide for displays, which is characterized by its long length. One light entering surface on which light is incident, one light emitting surface that is arranged at a position facing the light receiving sensor and the emitted light is guided to the light receiving sensor, and light incident on the light receiving surface. A light guide body for a display including a light guide unit that guides light to the light emitting surface.
The light guide portion has a central portion having a central portion having a lower refractive index than the light guide portion, a first angle range in which the incident angle with respect to the display surface is small, and a third angle in which the incident angle with respect to the display surface is large. The light incident on the incoming surface from the second angle range between the ranges is guided to the outgoing surface.
At least one of the incoming surface side and the outgoing surface side of the central portion is in a direction different from the outgoing surface after the light incident on the incoming surface from the first angle range is incident on the light guide portion. It is a V-shaped or inclined reflecting surface that reflects to
On the light entrance surface side of the outer surface of the light guide portion, light incident on the light entrance surface from the third angle range passes through the light guide portion and is transmitted to the outside of the light guide portion. Is a face
The transmission surface has a rectangular shape in which the light entry surface side protrudes most outward and swells outward.
The length of the central portion from the incoming surface side to the outgoing surface side is the width of the incoming surface, which is the distance between the one transmitting surface and the other transmitting surface in the light guide portion. A light guide for displays, which is characterized by its long length. One light entering surface on which light is incident, one light emitting surface that is arranged at a position facing the light receiving sensor and the emitted light is guided to the light receiving sensor, and light incident on the light receiving surface. A light guide body for a display including a light guide unit that guides light to the light emitting surface.
The light guide portion has a central portion having a central portion having a lower refractive index than the light guide portion, a first angle range in which the incident angle with respect to the display surface is small, and a third angle in which the incident angle with respect to the display surface is large. The light incident on the incoming surface from the second angle range between the ranges is guided to the outgoing surface.
At least one of the incoming surface side and the outgoing surface side of the central portion is in a direction different from the outgoing surface after the light incident on the incoming surface from the first angle range is incident on the light guide portion. It is a V-shaped or inclined reflecting surface that reflects to
On the light entrance surface side of the outer surface of the light guide portion, light incident on the light entrance surface from the third angle range passes through the light guide portion and is transmitted to the outside of the light guide portion. Is a face
The light-transmitting surface side of the transmissive surface protrudes most outward, and is an uneven surface.
The length of the central portion from the incoming surface side to the outgoing surface side is the width of the incoming surface, which is the distance between the one transmitting surface and the other transmitting surface in the light guide portion. A light guide for displays, which is characterized by its long length.

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