JP2012081780A - Head-up display lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the thickness of a head-up display lamp and prevent the reflection of an image of a component of the head-up display lamp on a front window by external light, etc.SOLUTION: The head-up display lamp 1 is disposed below a front window 93 of a vehicle. The head-up display lamp 1 includes a light guide plate 30 and a light source 20. The light guide plate 30 includes: an incident surface 31 which counters to the light source 20 and receives light emitted from the light source 20; a light-outgoing surface 32 which extends backward from the upper edge of the incident surface 31, sloping and rising backward, thus forming a concave surface; a reflection surface 33 which extends backward from the lower edge of the incident surface 31 and is counter to the light-outgoing surface 32; and a plurality of dots 37 which are formed on the reflection surface 33 and reflect and scatter light having fallen onto the incident surface 31.

Description

  The present invention relates to a head-up indicator lamp.

  2. Description of the Related Art Conventionally, a head-up display that displays a virtual image by projecting light emitted from a display device onto a front window of a vehicle is known (see, for example, Patent Document 1). In the head-up display described in Patent Document 1, the case (25) is attached to the inside of the instrument panel, an opening is formed on the upper surface of the case (25), and the display (21 ), A reflecting mirror (23) and a convex lens (22) are accommodated. Light emitted from the display (21) is projected onto the front window (2) above the case (25) by the reflection mirror (23) and the convex lens (22). Further, the opening of the case (25) is closed by the transparent cover (24) so that when the driver looks at the front window (2), the external light reflected by the cover (24) cannot be visually recognized. It has become.

JP 2004-130892 A

However, the indicator (21), the reflection mirror (23), and the convex lens (22) inside the case (25) may be illuminated by external light transmitted through the cover (24). In that case, images of the display (22), the reflection mirror (23), and the convex lens (22) appear on the front window. The driver who saw the statue will feel uncomfortable.
Further, since the reflecting mirror (23) and the convex lens (22) are used, an optical path from the convex lens (22) to the display (21) must be secured, and the head-up display becomes larger and thicker. End up.
Therefore, the problem to be solved by the present invention is to reduce the thickness of the head-up indicator lamp and to prevent the image of the components of the head-up indicator lamp from being reflected on the front window due to external light or the like.

  In order to solve the above problems, a head-up indicator lamp according to the present invention is a head-up indicator lamp disposed below a front window of a vehicle, and includes a light guide plate and a light source that emits light, A light guide plate facing the light source and receiving light emitted from the light source; an exit surface extending rearward from an upper edge of the incident surface; inclined upward and curved concavely; A reflection surface extending backward from a lower edge of the surface and facing the emission surface; and a plurality of dots formed on the reflection surface and reflecting so as to scatter light received by the incident surface.

  Preferably, the light guide body is further provided between the rear edge of the reflection surface and the rear edge of the emission surface on the opposite side of the incident surface, and further has a wedge-shaped end portion having a wedge shape in cross section.

  Preferably, the plurality of dots have an elliptical distribution.

  Preferably, the plurality of dots are provided in a prism shape by processing the reflection surface to be uneven.

  Preferably, the head-up indicator lamp is further provided with a matte surface that is disposed so as to face rearward above the light source and is matted.

According to the present invention, since the light guide plate is used, the head-up indicator lamp can be thinned.
Since the exit surface of the light guide plate is inclined upward and curved concavely, external light such as sunlight is reflected forward by the exit surface. Therefore, the external light reflected by the exit surface is not projected on the front window, and the image of the light guide plate is also difficult to appear on the front window. Therefore, the driver's dazzling due to external light is prevented and the driver does not feel uncomfortable.

It is a vertical sectional view of a head-up indicator lamp according to an embodiment of the present invention. It is the vertical sectional view which expanded and showed the rear part of the head up indicator lamp concerning the embodiment. It is the vertical sectional view which expanded and showed the central part of the head up indicator lamp concerning the embodiment. It is the vertical sectional view which showed the light ray of the external light which injected into the head-up indicator lamp which concerns on the embodiment. It is the vertical sectional view which showed the light ray of the light irradiated with the head-up indicator lamp concerning the embodiment.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. However, the embodiments described below are given various technically preferable limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

  FIG. 1 is a cross-sectional view of the head-up indicator lamp 1. The cross section shown in FIG. 1 is a vertical cross section along the longitudinal direction of the vehicle.

  The head-up indicator lamp 1 is attached to an instrument panel 91 in the passenger compartment. The instrument panel 91 is located below the front window 93 of the vehicle, an opening 92 is formed on the upper surface of the instrument panel 91, and the head-up indicator lamp 1 is disposed in the opening 92. The head-up indicator lamp 1 irradiates the front window 93 and makes the driver visually recognize the irradiated light. The head-up indicator lamp 1 is used, for example, as a warning lamp and displays a warning. The display content by turning on / off / flashing the head-up indicator lamp 1 is not limited to the warning.

The head-up indicator lamp 1 includes a housing 10, a light source 20, a light guide plate 30, and the like.
The housing 10 is provided in the shape of a box having a hollow, the upper surface thereof is open, and an opening 11 is formed. The housing 10 is black, and the inner surface of the housing 10 is matted (matted).

  A bottom surface 12 of the housing 10 is inclined rearward and curved in a bow shape, particularly a concave shape when viewed from the left and right. At the upper end of the housing 10, a flange 13 protruding in the radial direction of the opening 11 is formed. The housing 10 is accommodated in the opening 92 of the instrument panel 91, and the flange 13 is locked to the instrument panel 91 around the opening 92.

  A mounting hole 14 is formed in the front surface of the housing 10 and in the lower part thereof. The mounting hole 14 is fitted with the substrate 21 in an upright state. The front side surface of the substrate 21 faces rearward, the rear side surface of the substrate 21 faces frontward, and the mounting hole 14 is blocked by the substrate 21. A cover 15 is attached to the front surface outside the housing 10, the front side of the attachment hole 14 is closed by the cover 15, and the back side surface of the substrate 21 is supported by the cover 15.

  A light source 20 is mounted on the front surface of the substrate 21, and the light emission direction of the light source 20 (the direction in which the light emission intensity is highest) is backward. The light source 20 is a light emitting diode, a laser diode, an inorganic electroluminescence element, an organic electroluminescence element, or other semiconductor light emitting elements. The number of light sources 20 mounted on the substrate 21 is one or more. When the number of light sources 20 is two or more, the light sources 20 are arranged in one or more rows in the left-right direction (direction perpendicular to the paper surface). The light source 20 may be a fluorescent tube such as a cold cathode tube.

  A light guide plate 30 is laid on the bottom surface 12 in the housing 10. The light guide plate 30 is a translucent member that is curved along the bottom surface of the housing 10. The light guide plate 30 will be described in detail.

The light guide plate 30 includes an entrance surface 31, an exit surface 32, a reflection surface 33, a wedge-shaped end portion 34, a plurality of dot prisms 37, and the like.
The incident surface 31 is a front side surface of the light guide plate 30. The incident surface 31 faces the light source 20 and receives light emitted from the light source 20. The incident surface 31 may be in contact with the light source 20 or may be separated from the light source 20.
The emission surface 32 is an upper surface on the front side of the light guide plate 30. The exit surface 32 is adjacent to the entrance surface 31 at the upper edge of the entrance surface 31 and extends rearward from the upper edge of the entrance surface 31. The emission surface 32 is inclined rearward and curved in a bow shape, particularly a concave shape when viewed from the left and right. For example, in the vertical section along the front-rear direction, the exit surface 32 draws a parabola or a free curve based on it.
The reflection surface 33 is a lower surface on the back side of the light guide plate 30. The reflecting surface 33 is adjacent to the incident surface 31 at the lower edge of the incident surface 31 and extends backward from the lower edge of the incident surface 31. The reflection surface 33 is inclined rearward and curved in a bow shape, particularly a convex shape when viewed from the left and right. Further, the reflection surface 33 faces the emission surface 32 and is substantially parallel to the emission surface 32. The reflecting surface 33 faces the bottom surface 12 of the housing 10.

FIG. 2 is a vertical sectional view showing a rear portion of the light guide plate 30.
As shown in FIG. 2, the vertical cross-sectional shape of the end 34 provided between the rear edge of the reflection surface 33 and the rear edge of the emission surface 32 on the opposite side of the incident surface 31 is provided in a wedge shape. The wedge-shaped end portion 34 has emission preventing surfaces 35 and 36 which are side surfaces opposite to the incident surface 31. The emission preventing surface 35 is adjacent to the emission surface 32 at the rear edge of the emission surface 32. The emission preventing surface 35 is inclined with respect to the emission surface 32, and the inner angle between the emission preventing surface 35 and the emission surface 32 is an obtuse angle. The emission preventing surface 36 is adjacent to the reflecting surface 33 at the rear edge of the reflecting surface 33. The emission preventing surface 36 is inclined with respect to the reflecting surface 33, and the inner angle between the emission preventing surface 36 and the reflecting surface 33 is an obtuse angle. The emission preventing surface 35 and the emission preventing surface 36 are adjacent to each other at the rear end, and the inner angle between the emission preventing surface 35 and the emission preventing surface 36 is an acute angle.

FIG. 3 is a vertical sectional view showing a central portion of the light guide plate 30.
As shown in FIG. 3, a plurality of dot prisms 37 are formed in a protruding state at the center of the reflecting surface 33. The dot prism 37 has a triangular cross section, and is provided in a conical shape, for example. These dot prisms 37 are distributed in the central part of the reflecting surface 33, but the distribution range of these dot prisms 37 is inside an ellipse whose major axis is the left-right direction (direction perpendicular to the paper surface of FIG. 3). .

Next, characteristics of the head-up indicator lamp 1 will be described.
As shown in FIG. 4, external light such as sunlight (particularly, light from obliquely above the rear side) passes through the front window 93 and enters the emission surface 32 of the light guide plate 30. Further, since the emission surface 32 is inclined rearward and upward, external light incident on the emission surface 32 is totally reflected toward the front inner surface 16 of the housing 10. Since the emission surface 32 is provided in a concave shape, the external light reflected by the emission surface 32 is collected at a predetermined focal point on the front inner surface 16. Since the front inner surface 16 facing back is a mat surface, the reflected light incident on the front inner surface 16 is attenuated and scattered (diffuse reflected). Therefore, since the external light reflected by the emission surface 32 is not projected on the front window 93, the external light is not reflected on the front window 93. Therefore, the driver's dazzling due to external light is prevented. Further, since the light totally reflected by the emission surface 32 is reflected forward, the image of the light guide plate 30 is not displayed on the front window 93. Therefore, the driver does not feel uncomfortable.
When external light from directly above or obliquely upward is incident on the exit surface 32 of the light guide plate 30, the reflected light is projected onto the front window 93, but the projection position is out of the driver's field of view. Even if the light is reflected by the front window 93, the light does not go to the driver, so that the driver is not dazzled.

  As shown in FIG. 5, when the light source 20 emits light, the light emitted from the light source 20 enters the incident surface 31 and is received by the incident surface 31 inside the light guide plate 30. The light incident on the incident surface 31 repeats total reflection on the reflecting surface 33 and the emitting surface 32 and spreads inside the light guide plate 30.

  Further, since the emission preventing surfaces 35 and 36 are inclined with respect to the emission surface 32 and the reflection surface 33, even if the light guided into the light guide plate 30 reaches the rear end portion 34 of the light guide plate 30. The light is totally reflected by the emission preventing surfaces 35 and 36 and returns to the incident surface 31 side.

Since the prism dot 37 is formed at the center of the reflecting surface 33, the light guided to the inside of the light guide plate 30 is scattered by the prism dot 37. The light reflected so as to be scattered by the prism dots 37 enters the exit surface 32 at an angle smaller than the critical angle, and exits the light guide plate 30 from the exit surface 32. The light emitted from the emission surface 32 is projected on the front window 93 and reflected on the front window 93. Since the plurality of prism dots 37 have an elliptic distribution, the shape of the image of the light reflected on the front window 93 is an ellipse. In particular, the distribution state of the prism dots 37 and the shape of each prism dot 37 are designed so that the image of the light reflected on the front window 93 is brighter at the center and darker toward the outside.
The driver can view the image of the light reflected on the front window 93.

According to the embodiment of the present invention, since the light guide plate 30 is used, the head-up indicator lamp 1 can be thinned.
Further, the shape of the emission surface 32 can prevent the driver from being dazzled or uncomfortable.
In addition, since the light guide plate 30 is used, the light source 20 is hardly illuminated by external light, so that the image of the light source 20 does not appear on the front window 93 when the light source 20 is turned off. Therefore, it is possible to prevent the driver from feeling uncomfortable.

In the above embodiment, a plurality of prism dots 37 are formed by processing the central portion of the reflection surface 33 to be uneven, and light is scattered by the prism dots 37. On the other hand, a plurality of reflective dots may be spotted at the center of the smooth reflective surface 33. The reflective dot is a white or metallic thin film formed in a dot shape by printing or the like, and the light guided into the light guide plate 30 is reflected so as to be scattered by a plurality of reflective dots. However, it is incident on the exit surface 32 at an angle smaller than the critical angle and exits from the exit surface 32 to the outside of the light guide plate 30. These reflective dots also have an elliptical distribution.
Further, the inner surface of the housing 10 and the front inner surface 16 are matte processed, but may be antireflection processed. For example, the inner surface 16 of the housing 10 or the front inner surface 16 has a minute uneven shape, is a textured surface, is subjected to an AR coating (Anti-Reflection coating) treatment, or a non-woven fabric or flocking (the non-woven fabric or flocking is dark or black) If it is attached, the inner surface of the housing 10 is subjected to antireflection treatment.

DESCRIPTION OF SYMBOLS 1 Head-up indicator lamp 16 Front inner surface 20 Light source 30 Light guide plate 31 Incident surface 32 Output surface 33 Reflective surface 34 Wedge-shaped edge part 37 Dot prism

Claims (5)

A head-up indicator lamp disposed below the front window of the vehicle,
A light guide plate;
A light source that emits light,
The light guide plate is
An incident surface facing the light source and receiving light emitted from the light source;
An exit surface extending rearward from the upper edge of the entrance surface, inclined upward and curved concavely;
A reflective surface extending backward from the lower edge of the incident surface and facing the exit surface;
A head-up indicator lamp, comprising: a plurality of dots formed on the reflecting surface and reflecting so as to scatter light received by the incident surface.   The light guide is further provided between a rear edge of the reflection surface and a rear edge of the emission surface on the opposite side of the incident surface, and further has a wedge-shaped end portion having a wedge shape in cross section. Item 2. The head-up indicator lamp according to Item 1.   The head-up indicator lamp according to claim 1, wherein the plurality of dots have an elliptical distribution.   The head-up indicator lamp according to any one of claims 1 to 3, wherein the plurality of dots are provided in a prism shape by processing the reflection surface to be uneven.   The head-up indicator lamp according to any one of claims 1 to 4, further comprising a matte surface disposed rearwardly above the light source and matted.

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