JP6424457B2 - Automotive display device - Google Patents

Description

  The present invention relates to an illumination device and a display device mainly used for illumination light path control, and in particular, an illumination device for reducing an image reflection on a windshield of a car in an in-vehicle display device, and an automotive device provided with the illumination device. The present invention relates to a technique suitable for use in a display device.

  A liquid crystal display is generally used as a vehicle-mounted display device. Since the liquid crystal display is a non-self light emitting display, an illumination device is provided on the back of the liquid crystal panel. A plurality of cold cathode fluorescent lamps and LEDs (Light Emitting Diodes) are used as a light source, and an edge light type illumination device using a light guide plate is generally used.

  By the way, a large amount of light is emitted not only in the driver's direction but also in all oblique directions from a general lighting device used for a liquid crystal display. Therefore, from the on-vehicle display device provided with a general illumination device, image light is emitted in a direction not required by the driver or other observers. Among such lights, the light emitted to the windshield of the car is reflected by the windshield and enters the eyes of the driver, which is a major safety issue.

  With respect to such a problem, a light control film (Patent Document 1) that limits the light emission direction may be used. The light control film is a view control film having a minute louver structure, and is absorbed by the black layer except the light emitted in the specific view direction. However, there is a problem that a periodic louver structure generates moire interference fringes with a pixel structure of a liquid crystal panel, and a problem that light utilization efficiency is largely reduced because the black layer absorbs light.

  Patent Document 2 shows the degree of absorption of light by the black louver structure. As one example, it can be seen that the luminance is lowered not only in the oblique direction but also in the front direction by 30% when the diffused light emitted from the diffusion hollow light box is incident on the louver structure.

JP 2001-305312 A JP 2011-508262 gazette

However, in the Patent Document 1 described technology and Patent Document 2 described technology utilizes a light absorbing material, not being used for display all amount of light incident, thus the viewer in these techniques There is a need for a display device that can be perceived as darker and that can be perceived as brighter with the same power consumption.
Further, among the in-vehicle display devices, for example, when the device is of a storable type, the installation position and the angle can not be changed, so that it is particularly required to prevent the windshield reflection and the like.
Furthermore, there is also a need to provide a display device that realizes such a request at low cost.

  The present invention has been made to solve the conventional problems as described above, and a lighting device having high light utilization efficiency by controlling the emission direction regardless of light absorption and a display device using the lighting device Intended to be provided.

The in-vehicle display device according to the present invention is an in-vehicle display device including an illumination device, wherein the illumination device is substantially rectangular in plan view and faces the first main surface and the first main surface to be an emission surface, A light-transmissive light guide having a second main surface, a light source disposed to face an incident surface of the light guide, and a first light source disposed on the second main surface side of the light guide A lens sheet and a diffusive sheet are provided, and in the light guide, a surface extending in the X direction among the side end surfaces connecting the first main surface and the second main surface is the incident surface. A concave or convex light deflection element is formed on the first main surface of the light guide for deflecting light incident from the incident surface and guided in the light guide toward the second main surface. The light deflection element of the light guide is formed of a reflective surface and an inclined surface so that the cross-sectional shape orthogonal to the X direction is substantially triangular, The direct reflection can reflecting surface the light incident from the light source is the first main surface and made corner is set within a range of 10 ° inclusive 1 °, the second major surface of the light guide, said guide A lens array is provided which extends in the Y direction which is the normal direction of the light entrance surface of the light body,
Wherein the first lens sheet, the second major surface opposite to the surface of the light guide extends in the entrance surface substantially parallel direction of the light guide, in a direction orthogonal to the extending direction The apex angle is 50 ° or more and 70 ° so that the emission light peak from the first lens sheet is inclined in the range of 3 ° or more and 10 ° or less with respect to the normal direction of the emission surface of the first lens sheet The above problems are solved by providing a prism lens set in the following range.
The present invention, in the lighting device, concave or convex of the light deflection elements are formed on the first major surface of the lightguide, the inclined surface in a substantially triangular shape in the direction normal to the cross section of the incident surface It is more preferable that the angle with the first main surface be in the range of 40 ° to 70 °.
The present invention, in the lighting device, the light deflecting element which is formed on the first major surface of the lightguide, can be a substantially triangular prism lens extending in a direction parallel with the incident surface is there.
Also, the present invention provides the illumination device, the light deflecting element which is formed on the first major surface of the lightguide, may be employed means a dot shape interspersed each independently.
Further, in the lighting device, the light deflecting element which is formed on the first major surface of the front Kishirubekotai is concave or convex dot shape, each of which is independently arranged, the light deflection element The light deflection element density D, which represents the number of light sources per unit area, decreases once as the distance from the incident surface increases in the Y direction and then increases, and the incident surface and the surface facing the incident surface When the distance up to L is L, the position where the light deflection element density D is minimum can be set in the range of L / 10 or more and 4 × L / 10 or less from the incident surface.
In the illumination device, the arrangement pattern of the light deflection elements is divided into a plurality of areas in the Y direction, and the arrangement pitch of the light deflection elements in the X direction is substantially constant in the same area. The light deflection element density D is such that the arrangement pitch of the light deflection elements in the Y direction increases with distance from the light entry surface to the position where the light deflection element density D is minimum from the light entry surface. from the position with the smallest to the incident surface which faces varies to be smaller as away is from the incident surface, among the plurality of regions, the array pitch of the light deflection element in the X-direction is discontinuously As the area changing and moving away from the incident surface increases, the area between the areas up to the position where the light deflection element density D becomes minimum, and the light deflection element density D becomes the minimum That decreases in between region until a surface that faces the incident surface from the position, the arrangement pitch of the light deflection element in the Y direction can be changed discontinuously between the regions.
Further, in the lighting device, the lens array formed on said second major surface of the lightguide, an aspect ratio of 2% to 60% or less of the lenticular lens array, a prism lens array or be a round prism array, it can.
In the lighting device, a reflective sheet may be provided at a position facing the first main surface of the light guide.
In the illumination device according to the present invention, the reflective sheet is preferably a specular reflective sheet.
In the illumination device, a second lens sheet is further provided between the first lens sheet and the diffusive sheet, and a surface of the second lens sheet facing the first lens sheet is provided with: A round prism or a lenticular lens may be formed to extend in a direction substantially normal to the light incident surface of the light guide.
The in-vehicle display device of the present invention preferably includes a lighting device described in any of the above, and a picture image display device you define a display image in accordance with the transmission / light shielding for each pixel .

The in- vehicle display device according to the first invention of the present invention is an in- vehicle display device including an illumination device, and the illumination device is substantially rectangular in plan view and faces the first main surface and the first main surface. And a light guide having a second main surface to be an exit surface, a light source arranged to face the incident surface of the light guide, and a light guide disposed on the second main surface side of the light guide face and the first lens sheet, e Preparations and diffusive sheet, a light guide body, which extends in the X direction in the side end surface for connecting the second main surface and the first main surface to be Is the incident surface, and the first main surface of the light guide is concave or convex for deflecting light incident from the incident surface and guided in the light guide toward the second main surface. The light deflection element of the light guide is formed, and the light deflection element of the light guide has a reflecting surface such that the cross-sectional shape orthogonal to the X direction is substantially triangular. Formed by the inclined surface, the direct reflection can reflecting surface the light incident from the light source is set within a range wherein the first main surface and made corners of 10 ° or less than 1 °, the said light guide second on the main surface, the lens array extending in the Y direction as a normal direction of the incident surface of the light guide is provided, the first lens sheet, and the second major surface of the light guide on opposite sides, extending in the incident surface substantially parallel direction of the light guide, light emitted peak from the first lens sheet in a direction orthogonal to the extending direction, the first lens sheet of the inclined within a range of 3 ° to 10 ° with respect to the normal direction of the exit surface, the apex angle is a feature in that it comprises a prism lens formed is set in the range of 50 ° to 70 ° or less.

  According to the present invention, the first main surface is a light transmitting element having a substantially triangular shape in cross section and one side of the oblique side having an angle of 1 ° or more and 10 ° or less and a lens array on the second main surface. A first lens sheet provided with a light, a prism lens having an apex angle in the range of 50 ° to 70 °, and a diffusive sheet, thereby extending the prism lens constituting the first lens sheet It is possible to obtain a collected luminance distribution in which the half-value angle on one side of the emission luminance distribution in the direction cross section orthogonal to the existing direction is in the range of 10 ° to 20 °. Furthermore, the peak of the emission luminance distribution is inclined in the range of 3 ° to 10 ° with respect to the normal direction of the first lens sheet emission surface. Accordingly, it is possible to significantly reduce the amount of light emitted in the direction of being reflected to the windshield of the car among the light emitted from the lighting device.

The second invention in the present invention, in the lighting device in the first invention, the concave or convex of the light deflection elements are formed on the first major surface of the lightguide in the Y-direction section The other formed angle in the substantially triangular shape is in the range of 40 ° to 70 °.
According to the present invention, since the angle of the other oblique side in the Y direction cross section of the concave or convex light deflection element formed on the first main surface of the light guide is 40 ° or more, the light is guided inside the light guide The light scattered by the other slope can be significantly reduced. On the other hand, it is desirable to set it as 70 degrees or less from the moldability of a light guide.

The third invention in the present invention, in the lighting device in the first invention or the second invention, the light deflecting element which is formed on the first major surface of the lightguide, the X-direction It is characterized in that it is a substantially triangular prism lens that extends.
According to the present invention, since the light deflection element is a prism lens extending in the X direction, it is possible to uniformly deflect the light incident on the light guide from the light source via the incident surface.

A fourth invention of the present invention, in the lighting device in the first invention or the second invention, the light deflecting element which is formed on the first major surface of the lightguide, each independently It is characterized by dotted dot shape.
According to the present invention, the light deflection elements are less likely to be visually recognized because they are disposed in the form of dots dispersed independently and dispersed in the plane. In addition, it is desirable because the adjustment is easy when local light and dark parts and the like occur in the in-plane luminance of the lighting device.

A fifth invention of the present invention, in the lighting device in the fourth invention, the light deflecting element which is formed on the first major surface of the lightguide or concave, each of which is disposed independently The light deflection element density D, which has a convex dot shape and represents the number of light deflection elements per unit area, decreases and then increases as the distance from the incident surface increases in the Y direction. When the distance between the light incident surface and the surface facing the light incident surface is L, the position where the light deflection element density D is minimum is in the range of L / 10 to 4 × L / 10 from the light incident surface. It is characterized in that it is set to.
According to the present invention, the light deflection element density D decreases as it goes away from the incident surface, and then increases, so that a vehicle-mounted display device with high luminance uniformity can be obtained.

According to a sixth invention of the present invention, in the illumination device of the fourth invention or the fifth invention, the arrangement pattern of the light deflection element is divided into a plurality of regions in the Y direction, In the region, the arrangement pitch of the light deflection elements in the X direction is substantially constant, and the arrangement pitch of the light deflection elements in the Y direction is a position at which the light deflection element density D becomes minimum from the incident surface. until so that as larger distance from the incident surface, from a position light deflecting element density D is minimized to the surface that faces the incident surface changes to become smaller as away is from the incident surface, the plurality of regions In the meantime, the arrangement pitch of the light deflection elements in the X direction changes discontinuously and the light deflection element density D is minimized as the area further away from the incident surface The distance between the regions up to the position is large, and the distance between the regions from the position where the light deflection element density D is minimum to the surface facing the incident surface is small, and the arrangement pitch of the light deflection elements in the Y direction Is characterized by changing discontinuously between the regions.
According to the present invention, the arrangement pattern of the light deflection elements is divided into a plurality of areas in the Y direction, and the arrangement pitch of the light deflection elements is hardly visible by changing the arrangement pitch in the X direction discontinuously between the areas. It becomes possible to design easily.

Seventh aspect of the present invention is the illumination device in any of the above invention of the first to sixth lens array formed on said second major surface of the lightguide, 2% or more aspect ratio 60 It is characterized in that it is a lenticular lens array of not more than%, a prism lens array, or a round prism array.
According to the present invention, by forming a lens array having an aspect ratio of 2% or more and 60% or less on the second main surface of the light guide, 2 extending in the Y direction among the four side end surfaces of the light guide A highly efficient in- vehicle display device can be obtained by reducing the light leaking from the two side end faces to the outside of the light guide.

An eighth invention according to the present invention is characterized in that, in the illumination device according to any one of the first to seventh inventions, a reflective sheet is provided at a position facing the first main surface of the light guide. Do.
The ninth invention of the present invention is characterized in that, in the illumination device of the eighth invention, the reflection sheet is a specular reflection sheet.
According to the present invention, by providing a reflection sheet at a position facing the first main surface, light leaking from the first main surface to the outside of the light guide can be reflected via the light deflection element, and a highly efficient vehicle-mounted display The device can be obtained. In the present invention, in particular, a specular reflection sheet is desirable.

In a tenth aspect of the present invention, in the illumination device according to any one of the first to ninth aspects, a second lens sheet is further provided between the first lens sheet and the diffusion sheet. A round prism or a lenticular lens extending in a direction substantially normal to the light incident surface of the light guide is formed on the surface of the second lens sheet facing the first lens sheet. It is characterized by
According to the present invention, it is possible to enlarge the field of view in the direction orthogonal to the extending direction of the lens forming the second lens sheet. That is, by narrowing one field of view with the first lens sheet, the amount of light at an angle to be reflected on the windshield is greatly reduced, and by widening the other field of view, an observer sitting in the driver's seat and passenger's seat of the car The amount of light in the direction can be increased.

An eleventh invention of the present invention is a vehicle-mounted display device, comprising: the lighting device according to any one of the first to tenth inventions; and a display image according to transmission / light shielding in pixel units And an image display element defining the image.

According to the present invention, there is provided a light guide including a lens array for controlling the internal light guide and a light deflection element for deflecting the path of the internal light guide and emitting the light to the outside, and the light emitted from the light guide Using the first lens sheet for condensing and emitting light, thereby reducing the light reflected on the windshield by the lens function regardless of light absorption, and using the highly efficient lighting device and the lighting device It is possible to achieve the effect that an in- vehicle display device can be provided.

It is a schematic cross section which shows 1st Embodiment of the illuminating device concerning this invention. It is an enlarged view explaining the light path by the light deflection element of the light guide in a 1st embodiment of the lighting installation concerning the present invention. It is an enlarged view explaining the optical path by the 1st lens sheet in a 1st embodiment of the lighting installation concerning the present invention. It is a schematic diagram which shows arrangement | positioning in 1st Embodiment of the illuminating device concerning this invention. In the first embodiment of the illumination device according to the present invention, (a) a perspective view of a light guide in which the light deflection element is a concave prism lens, (b) a light guide in which the light deflection element is a convex prism lens It is a perspective view. In the first embodiment of the lighting device according to the present invention, (a) a view for explaining the visibility of the light deflection element, (b) a view for explaining a diffusion image of the light deflection element. In the first embodiment of the lighting device according to the present invention, (a) a view for explaining the visibility of the light deflection element, (b) a view for explaining a diffusion image of the light deflection element. It is a figure explaining the arrangement pattern of a light deflection element in a 1st embodiment of a lighting installation concerning the present invention. It is a figure explaining the arrangement pattern of a light deflection element in a 1st embodiment of a lighting installation concerning the present invention. In a first embodiment of a lighting device that written to the present invention is a diagram illustrating the arrangement of the light deflection elements. It is a figure explaining surface luminance nonuniformity and center luminance in a 1st embodiment of an illuminating device concerning the present invention. It is a schematic cross section which shows 2nd Embodiment of the display concerning this invention. It is a graph which shows the horizontal direction cross-section luminance distribution in the illuminating device concerning this invention. It is a graph which shows the perpendicular direction cross-section luminance distribution in the illuminating device concerning this invention. It is a schematic diagram which shows the reflection in the illuminating device concerning this invention. It is a schematic diagram which shows the real arrangement in 2nd Embodiment of the display concerning this invention.

Hereinafter, a first embodiment of a lighting device according to the present invention will be described based on the drawings.
FIG. 1 is a schematic cross-sectional view showing a lighting device in the present embodiment, and in the figure, reference numeral 3 is a lighting device. In the figure, the reduction of each part does not coincide with the actual one.

  The illumination device 3 in the present embodiment includes a translucent light guide 7 which is a substantially rectangular plate-like sheet, a light source 6 disposed to face the incident surface 7L of the light guide 7, and a first lens. The sheet 8 and the diffusing sheet 9 are at least included. In addition, a reflection plate (reflection sheet) 5 may be included.

  Examples of the light source 6 include a point light source 6. Examples of the point light source 6 include LEDs (light emitting diodes), and examples of the LEDs include white LEDs and RGB-LEDs configured with red, green, and blue chips that are three primary colors of light. A plurality of point light sources 6 are disposed in the extending direction (X direction) of at least one of the four side end surfaces of the light guide 7 (the incident surface). Although FIG. 1 shows an example in which the light source 6 is disposed on one incident surface 7L of the light guide 7, the present invention is not limited to this, and the light source 6 may be disposed on two opposing end surfaces. Alternatively, the light source 6 may be a fluorescent tube represented by a CCFL (cold cathode tube) or a surface light source. Further, the shape of the light guide 7 may not be a flat plate shape as shown in FIG. 1, but may be a wedge shape or the like.

  The observer F side (the outer side in the Z direction) of the light guide 7 is the emission surface 7 b (second main surface), and the light deflection surface 7 a (first main surface) is formed on the surface opposite to the emission surface 7 b. The light deflection surface 7 a is composed of a flat surface and a light deflection element 18. The light deflection element 18 deflects the angle of the light guided inside the light guide 7 to the angle emitted from the emission surface 7 b. Although FIG. 1 illustrates the case where the light deflection element 18 is concave, it may be convex.

  On the other hand, a lens array 19 is formed on the exit surface 7 b of the light guide 7. The lens array 19 has an effect of guiding the light incident on the light guide 7 from the light source 6 through the incident surface 7L and controlling the light emitted from the light emission surface 7b. The lens array 19 has a prism shape extending in one direction, a lenticular lens shape, or a round prism shape, and the extending direction is a direction (Y direction) substantially orthogonal to the X direction. Here, the direction substantially orthogonal indicates a range of ± 10 ° with respect to 90 ° (orthogonal). That is, it substantially coincides with the optical axis direction of the light source 6. In some cases, the angle may be inclined to prevent an angle shift that occurs in the manufacturing method of the light guide 7 or a moire suppression when arranging a plate or sheet having a regular structure on the exit surface 7 b side of the light guide 7. At this time, if the range is ± 10 ° with respect to the X direction, the characteristics of the illumination device 3 of the present embodiment described later will not be significantly impaired.

The first lens sheet 8 is provided on the side of the exit surface 7 b of the light guide 7. The first lens sheet 8 is provided with a prism lens 2 0 on the exit surface 7b and the surface facing the light guide body 7, the other surface is flat, or matte surface. Prism lens 2 0 extends in the X direction and arranged in the Y direction, the apex angle is set in a range of 70 ° from 50 ° will be described later in detail. Also, the top of the prism may be rounded. This is because the abrasion resistance with the light guide 7 is improved. However, since it can impact the optical properties to be described later too rounded, it is desirable that 1/10 of the lens width of the prism lens 2 0 at a maximum.

Further, on the exit surface side of the first lens sheet 8, a diffusive sheet 9 is provided. The diffusive sheet 9 has an effect of suppressing moiré interference fringes generated between the light guide 7 and the first lens sheet 8 and reducing the apparent glare of the lighting device 3. Moreover, the effect of reducing the visibility of the light deflection element 18 disposed on the deflection surface 7 a of the light guide 7 is also provided.

  The illumination device 3 of the present embodiment may be provided with the reflection plate 5 on the light deflection surface 7 a side of the light guide 7 according to the purpose of use. The light guided in the light guide 7 from the light source 6 through the incident surface 7L is deflected by the light deflection element 18 formed on the light deflection surface 7a and emitted from the emission surface 7b, but a part of the light is The light is refracted and transmitted without being reflected by the light deflection element 18. Therefore, by providing the reflection plate 5 on the light deflection surface 7 a side, the effect of making the light emitted from the light deflection surface 7 a reenter the light guide 7 can be obtained, so the amount of light emitted to the observer side F It can be increased. The reflector 5 is preferably a specular reflector 5 in particular. When the white reflector 5 is disposed, it is desirable to select the white reflector 5 having a high specular reflection (regular reflection) rate. When a white reflective plate having a high diffuse reflectance is used, the amount of light emitted to the reflection angle to the windshield increases as the scattered light increases.

Hereinafter, the light guide 7 which comprises the illuminating device 3 in this embodiment is described in detail.
FIG. 2 is an enlarged view of the light deflection element 18 of the light guide 7.

  As shown in FIG. 2, the light deflection element 18 in this embodiment has a triangular shape in the Y-direction cross section, and the angle between the light deflection surface 7a and the reflection surface 18a, which is one oblique side, is θ1. Preferably, the angle θ1 is 1 ° or more and 10 ° or less.

If the light guide body 7 is a rectangular plate, the light incident to the optical deflector element 18 is missing from the light source 6 is a light deflection surface 7a, not emitted from any morphism exit surface 7b, repeatedly totally reflected within the light guide body 7 The light is emitted from the surface facing the incident surface 7L.
Thus, deflecting the path of the light optical guide by the light deflection elements 18, by breaking the total reflection condition of the light guide body 7 in the elevation exit surface 7b air, so that the light is emitted from the morphism exit surface 7b.
At this time, the smaller the angle θ1 between the light deflection surface 7a and the reflection surface 18a, which is one oblique side of the light deflection element 18, the smaller the angle of the emitted light (the narrower the angular distribution of the emission light). Can. Although the effect will be described later, it is desirable that the inclination angle θ1 of the reflecting surface 18a of the light deflection element 18 be 10 ° or less. If the inclination angle θ1 of the reflection surface 18a of the light deflection element 18 is too small, the amount of light which can be emitted out of the light to be guided is too small in the vicinity of the incident surface 7L of the light guide 7 The problem arises. Therefore, it is preferable that the inclination angle θ1 of one of the reflecting surfaces 18a of the light deflection element 18 be 1 ° or more.

When the angle between the light deflection surface 7a and the inclined surface 18b, which is the other oblique side of the light deflection element 18, is θ2, it is preferable that the angle be 40 ° or more and 70 ° or less. This is because it is desirable that the light guided inside the light guide 7 is deflected by the reflection surface (one oblique side) 18 a of the light deflection element 18. Light guided inside the light guide body 7, depending on the material of the light guide body 7, light guide at an angle of up to about 45 degrees to the optical deflecting surface 7a及beauty morphism exit surface 7b. Therefore, when the angle θ2 is smaller than 45 °, part of the light to be guided is deflected by the inclined surface (the other oblique side) 18 b of the light deflection element 18. However, it is desirable that the angle θ2 be 40 ° or more, because the light guided at about 45 ° is small. More desirably, it is 45 degrees or more. On the other hand, if the inclination angle θ2 of the inclined surface (the other oblique side) 18b is too large, a problem arises that molding of the light guide 7 becomes difficult. Therefore, it is desirable that the angle θ2 be 70 ° or less.
Also, an apex angle formed by the reflecting surface (one oblique side) 18a of the light deflection element 18 and the inclined surface (the other oblique side) 18b, and an angle formed by the reflecting surface (one oblique side) 18a and the light deflecting surface 7a And the angle formed by the inclined surface (the other oblique side) 18b and the light deflection surface 7a may be rounded.

FIG. 5 (a) is a perspective view of the light guide 7 as viewed from the light deflection surface 7a side in the case where the light deflection element 18 is a concave prism lens extending in the X direction, and FIG. These are the perspective views which looked at the light guide 7 from the light deflection | deviation surface 7a side in case the light deflection | deviation element 18 is a convex-shaped prism lens extended to a X direction.
When the light deflection element 18 is concave, as shown in FIG. 5A, the reflecting surface (one oblique side) 18a having an angle of 1 ° or more and 10 ° or less is located on the incident surface 7L side. On the other hand, when the light deflection element 18 is convex, as shown in FIG. 5B, the inclined surface (the other oblique side) 18b having an angle of 40 ° or more and 70 ° or less is positioned on the incident surface 7L side. It is arranged to do.

FIG. 3 is an enlarged view of the first lens sheet 8 in the illumination device 3 of the present embodiment.
The first lens sheet 8 has a prism lens 20, as shown in FIG. The light emitted from the light guide 7 is further deflected at an emission angle by the prism lens 20 of the first lens sheet 8. The apex angle θ3 of the prism lens 20 is constant regardless of the place, and the angle of incidence from the first lens sheet 8 and the apex angle θ3 of the prism lens 20 determine the emission angle from the first lens sheet 8.

That is, the light emitted from the first lens sheet 8 is narrower as the angle of the light emitted from the light guide 7 and incident on the first lens sheet 8 is limited (the angular distribution of the incident light is narrower). It is possible to collect light in the angular range. Therefore, as described above, the smaller the inclination angle θ1 of the reflection surface (one oblique side) 18 a of the light deflection element 18 of the light guide 7, the narrower the angular distribution of the light emitted from the light guide 7. desirable.
In the present embodiment, the peak angle of the light emitted from the first lens sheet 8 is inclined in a range of 3 ° to 10 ° (θL in the drawing) with respect to the normal direction of the first lens sheet 8 Is desirable.

FIG. 4 is a schematic view in the case where the display device 1 provided with the lighting device 3 of the present embodiment is actually provided in a car.
The display apparatus 1 is arrange | positioned between the dashboard 31 and the windshield 30 of a motor vehicle, as shown in FIG. At this time, the eye line is inclined by θL with respect to the normal direction Z of the display device 1 depending on the height of the driver. Therefore, it is desirable that the emission light peak angle of the illumination device 3 be inclined by θL with respect to the normal direction, and it is desirable that the angle be in the range of 3 ° or more and 10 or less. The apex angle of the prism lens 20 is set in the range of 50 ° to 70 ° so that the peak angle of the light emitted from the first lens sheet 8 is inclined in the range of 3 ° to 10 °.

  The top of the prism lens 20 on the side in contact with the light guide 7 may be rounded. This is because the abrasion resistance with the light guide 7 is improved. However, if the roundness is too large, the above-described light collecting effect is reduced, which is not desirable. As a result of verification by optical simulation, the radius of curvature is preferably 1/10 or less, more preferably 1/30 or less, with respect to the lens width of the prism lens 20. The prism lens 20 may have an isosceles triangle shape, but may have a left-right asymmetric triangle shape.

Next, the in-plane arrangement of the light deflection element 18 will be described in detail.
FIG. 6 is a view of the light guide 7 as seen from the light deflection surface 7 a side in the case where the light deflection element 18 is a prism lens extending the entire length of the light guide 7 in the X direction.

  In the illumination device 3 of this embodiment, as shown in FIG. 6, when the length of the light guide 7 is L, the light deflection element density D indicating the in-plane arrangement of the light deflection elements 18 is on the incident surface 7L side Set to turn upward after going down as you head in the Y direction. At this time, L0 is set in the range of L / 10 or more and 4 × L / 10 or less, where L0 is a point at which the light deflection element density D shifts from decrease to increase.

  In the present embodiment, since the inclination angle θ1 of the reflection surface (one oblique side) 18 a of the light deflection element 18 formed in the light guide 7 is set in the range of 1 ° to 10 °, the light guide The angular distribution of the light emitted from the light source 7 can be narrowed to provide a lighting device 3 that is condensed to a narrow angular range by the first lens sheet. As described above, since the light deflected in the direction emitted by the light deflection element 18 is limited, it becomes difficult to emit in the vicinity of the incident surface 7L.

On the other hand, since the amount of light incident on the light guide 7 decreases with distance from the incident surface 7L, the light deflection element density D needs to be increased with distance from the incident surface 7L.
In the present embodiment, as shown in FIG. 6, the light deflection element density D in the Y direction in the light guide 7 is set high in the vicinity of the incident surface 7L, and is decreased to the position of L0. When L0 is exceeded, it is possible to suitably control the amount of emitted light near the incident surface 7L and at a position separated from the incident surface 7L by setting to shift to a rise.

  In the drawing, although the light deflection element 18 is a prism lens extending the entire length of the light guide 7 in the X direction, there is a portion where the light deflection element 18 does not extend continuously along the entire length of the light guide 7 in the X direction Alternatively, the light deflection element 18 may be intermittently extended along the entire length of the light guide 7 in the X direction. Even in this case, it is possible to suitably control the amount of light emitted in the vicinity of the incident surface 7L and at a position separated from the incident surface 7L.

Next, the case where the light deflection elements 18 are in the form of dots arranged independently of one another will be described.
FIG. 7 is a view of the light guide 7 in which the light deflection element 18 has a dot shape as viewed from the light deflection surface 7 a side. In FIG. 7, for the sake of simplicity, the light deflection element 18 is shown for the arrangement from the above L0 to L, and the dot arrangement from the incident surfaces 7L to L0 is omitted.

  The arrangement pattern of the light deflection elements 18 is divided into a plurality of areas and set as shown in FIG. In the example of FIG. 7, the case where the area | region of the light guide 7 surface in a Y direction is divided | segmented into 3 area | regions of area | region ac is shown. The division and setting of the area is not limited to this example, and the number of divisions and the size of the area can be appropriately selected by the designer.

  In each of the regions a to c, the light deflection elements 18 are arranged in each region at a constant pitch in the X direction. On the other hand, in each of the regions a to c, the light deflection elements 18 in each region become smaller, and the pitch in the Y direction decreases as the distance from the incident surface 7L increases, and the light deflection element density D increases.

  Taking the region a as an example, as shown in FIG. 7, the pitch of the light deflection elements 18 in the X direction is constant at Pxa at any place. On the other hand, the pitch of the light deflection element 18 in the Y direction changes from Py (a1), Py (a2),... Py (an) from the side close to the incident surface 7L, The smaller the pitch, the smaller the value.

Further, in the area b, as shown in FIG. 7, the pitch of the light deflection elements 18 in the X direction is Pxb wherever it is and is smaller than Pxa in the area a. That is, at the boundary between the area a and the area b, the pitch in the X direction changes discontinuously, and the number of light deflection elements 18 per row arranged in the X direction is larger in the area b.
Similarly, in the area c, as shown in FIG. 7, the pitch of the light deflection elements 18 in the X direction is Pxc at any place and smaller than Pxb in the area b.
As described above, by changing the pitch in the X direction of the light deflection element 18 for each region, the visibility of the light deflection element 18 is suppressed, and the amount of light emitted in the vicinity of the incident surface 7L and at a distance from the incident surface 7L. Can be suitably controlled, and a high-intensity lighting device 3 can be provided.

In addition, when the pitch in the Y direction of the portion closest to the boundary in the region near the entrance surface 7L is compared with the pitch in the Y direction of the region closest to the boundary in the region far from the entrance surface 7L The pitch in the Y direction of the portion closest to the boundary in the region far from the incident surface 7L is set to be larger.
Specifically, at the boundary between the area a and the area b, when Py (an) and Py (b1) are compared, it is set such that Py (b1) is larger. That is, the pitch in the Y direction of the light deflection element 18 continuously changes in the same area, but changes discontinuously at the boundary between the two areas.

  On the other hand, the pitch in the Y direction (pointing to Py (a1), Py (b1), and Py (c1) in FIG. 7) close to the boundary on the incident surface 7L side in each region ac The magnitude of the pitch in the Y direction (referring to Py (an), Py (bn), and Py (cn) in FIG. 7) close to the boundary distant from the surface 7L is not particularly limited.

  Here, the range of calculation of the light deflection element density D will be described.

  If the area range for calculating the light deflection element density D is a minute range, the density D may be different depending on the setting position of the density D. Conversely, the area range for calculating the light deflection element density D is a wide range If it does, many density D will be averaged regardless of the setting position.

  FIG. 8 is a schematic view of the arrangement of the light deflection elements 18 in the X direction and the calculated area range of the light deflection element density D. As shown in FIG.

  In the present embodiment, as shown in FIG. 8, the arrangement pitch Px is constant in the X direction in the same region, so the light deflection element density D is constant, and the range for calculating the density D is the length in the X direction Does not depend on On the other hand, in the Y direction, the arrangement pitch Py decreases with distance from the incident surface 7L in the same area, so the light deflection element density D is determined by the distance between the adjacent light deflection elements 18.

  That is, the light deflection element density D is determined by the range surrounded by the broken line in FIG. In FIG. 4, the area of the boundary between the area a and the area b is R (m), and the number m decreases in the Y direction to the area a side, and the number m increases in the Y direction to the area b side. There is. Therefore, the distance between the area a and the area b is calculated so that the light deflection element density D changes continuously.

  Although the arrangement of the light deflection element 18 has been described above in the range from L0 to L, the arrangement from the incident surface 7L to L0 can be similarly set. Since the light deflection element density D decreases in reverse from the incident surfaces 7L to L0, the magnitudes from L0 to L described above may be set to be reversed. Furthermore, it is desirable to set the position of L0 not to be the boundary of two regions, but to be located within one region.

Next, the visibility of the light deflection element 18 will be described.
In the present embodiment, light incident from the light source 6 to the light guide 7 is guided inside the light guide 7, is deflected by the light deflection element 18 and is emitted from the emission surface 7 b. Therefore, when the light guide 7 is observed in detail from the side of the observer F on the outer side in the Z direction, each single light deflection element 18 is visually recognized. Depending on the arrangement of the light deflection element 18, the light deflection element 18 may be viewed.

In order to prevent this, the ratio Py / Px between the pitch Px in the X direction of the light deflection element 18 and the pitch Py in the Y direction is preferably in the range of 0.2 or more and 1.0 or less. This is because when Py / Px is set in this range, the visibility of the light deflection element 18 can be suppressed.
The arrangement where Py / Px is less than 0.2 is not preferable because it is visually recognized as linear light extending in the Y direction. On the other hand, in the case where Py / Px exceeds 1.0, it is not preferable because it is visually recognized as linear light extending in the X direction.

  In the light guide 7 according to the present embodiment, as shown in FIG. 7, with respect to the arrangement pattern of the light deflection elements 18 in the X-Y direction, the X direction rows of the light deflection elements 18 are half the arrangement pitch Px. They are alternately arranged in the X direction and arranged in the Y direction. However, the arrangement pattern of the light deflection elements 18 is not limited to this. For example, the light deflection elements 18 may be aligned without shifting in the X direction. Alternatively, the light deflection elements 18 may be arranged slightly offset in the X direction. Alternatively, the X-direction displacement of the light deflection element 18 may be set randomly.

  On the other hand, a lens array 19 is formed on the exit surface 7b of the light guide. The lens array 19 has a prism shape extending in the Y direction, a lenticular lens shape, or a round prism shape, and is arranged at a constant pitch in the X direction. At this time, the lens array 19 may be arranged with a gap. FIG. 5 shows the case where the shape of the lens array 19 is a lenticular lens. The lens array 19 controls the path of light guided in the light guide 7 and the emission direction of the light emitted from the emission surface 7 b.

  FIG. 9 illustrates the behavior of light guided inside the light guide 7 without the lens array 19. FIG. 9 (a) is a view as seen from the side of the exit surface 7b, and FIG. 9 (b) is a view as seen from the entrance surface 7L. Here, the case where one light source 6 is disposed on the incident surface 7L of the light guide 7 is illustrated in a simplified manner. FIG. 11A is a view showing the surface luminance distribution of the light guide 7 when the lens array 19 is not provided.

When the lens array 19 is not provided, light emitted from the light source 6 is incident on the light guide 7 from the incident surface 7L and is guided while expanding the inside of the light guide 7 in a fan shape.
In the light guide 7 without the lens array 19 which is an optical path control element, as shown in FIG. 11A, a triangular dark portion indicated by a symbol G in the drawing is generated. This is because the light incident on the light guide 7 from the light source 6 spreads in a fan-like manner and is guided as shown in FIG. It is a person who occurs due to light leakage from the side end face of the short side where the light source 6 is not disposed. Therefore, when the lens array 19 is not provided, when designing the arrangement of the light deflection elements 18, it is difficult to make the light deflection element density D in the X direction constant, and the sparse / dense design not only in the Y direction but also in the X direction Problem of having to deal with

  FIG. 10 illustrates the behavior of light guided inside the light guide 7 with the light path control element 19. FIG. 10 (a) is a view as seen from the side of the exit surface 7b, and FIG. 10 (b) is a view as seen from the entrance surface 7L. FIG. 11B is a view showing the surface luminance distribution of the light guide 7 when the lens array 19 is provided.

When the lens array 19 is provided, the light incident from the light source 6 has its reflection angle deflected by the inclined surface of the lens array 19, and is guided in the Y direction without spreading in a fan shape.
When the lens array 19 is provided as in the present embodiment, the light incident from the light source 6 does not spread in a fan shape and is guided in the Y direction, so the dark portion G as shown in FIG. 11A does not occur. . Further, as shown in FIG. 11B, the highly efficient lighting device 3 can be obtained with almost no leaked light from the short side end face where the light source 6 is not disposed.

  As described above, by preventing the leaked light from the two side end surfaces orthogonal to the incident surface 7 L of the light guide 7 by the lens array 19, it is possible to improve the efficiency and the surface luminance uniformity with high efficiency. As such a lens, as described above, a lenticular lens, a prism lens, or a round prism lens may be mentioned. However, if the aspect ratio of the lens array 19 (the ratio of the lens width to the lens height) is too low The fanned light spreads like a fan in the light guide 7 and propagates. On the other hand, when the aspect ratio is too high, the light incident from one light source 6 does not spread inside the light guide 7 and becomes difficult to be mixed with the other light sources 6, so that the unevenness of the light source 6 becomes visible easily. Therefore, it is desirable to set the aspect ratio of the lens array 19 in the range of 2% to 60%. More preferably, it is in the range of 5% to 33%.

  Furthermore, the lens array 19 has a function of reducing the visibility of the light deflection element 18. When the illumination device 3 of the present invention is applied as a backlight for a display, it is not desirable that the light deflection element 18 be viewed in the form of dots. If the light path control element 19 is a prismatic lens, the image of the light deflection element 18 is split. For example, if the lens array 19 is a triangular prism lens, the image of one light deflection element 18 is split into two images. Accordingly, the visibility of the light deflection element 18 can be easily reduced. On the other hand, when the lens array 19 is a curved lenticular lens, the point-like image of the light deflection element 18 is linearized, so that the visibility of the light deflection element 18 can be easily reduced.

  The lens array 19 may extend in the Y direction and may be arranged at regular or random intervals in the X direction. At this time, there may be a gap which is a flat surface between the lens arrays 19. If this gap is 10% or less of the pitch at which the lens array 19 is arranged, it does not affect the suppression function of the dark portion G and the reduction of the visibility of the light deflection element 18 described above. More preferably, the gap is 5% or less of the pitch at which the lens array 19 is arranged. By providing such a gap, the life of the molding die for the light guide 7 can be extended, and the occurrence of molding defects can be suppressed.

  The light guide 7 according to this embodiment is an acrylic resin represented by PMMA (polymethyl methacrylate), or PET (polyethylene terephthalate), PC (polycarbonate), COP (cycloolefin polymer), PAN (polyacrylonitrile copolymer) ), AS (acrylonitrile-styrene copolymer) and the like, the light deflection element 18 and the lens array by an extrusion molding method, an injection molding method, or a heat press molding method well known in the art. 19 can be integrally molded. Alternatively, after the flat light guide 7 is formed by the above-described method, the light deflection element 18 and the lens array 19 may be formed using a printing method, a UV curing resin, a radiation curing resin, or the like.

  In the light guide body 7 of the present embodiment, it is desirable that the light deflection element 18 and the lens array 19 be integrally formed by using the extrusion molding method, in particular, among the manufacturing methods described above. As a result, the number of processes for manufacturing the light guide 7 is reduced, and since roll-to-roll molding is performed, mass productivity is high.

  Since the light deflection elements 18 formed in the light guide 7 of the present embodiment are in a one-dimensional sparse / dense pattern, the width direction of the roll mold and the one-dimensional sparse / dense direction are made to coincide with each other. The circumferential direction is preferably arranged at a substantially constant interval. This makes it possible to form the light guide 7 in a seamless manner.

Hereinafter, a second embodiment of a lighting device according to the present invention will be described based on the drawings.
FIG. 12 is a schematic cross-sectional view showing a display device equipped with the illumination device in the present embodiment, and in the figure, reference numeral 1 is a display device. In the figure, the reduction of each part does not coincide with the actual one.

  The present embodiment differs from the above-described first embodiment in that the image display element 2 is provided, and the second lens sheet 10 is disposed between the first lens sheet 8 and the diffusive sheet 9. The corresponding components other than the above are denoted by the same reference numerals and the description thereof will be omitted.

The second lens sheet 10 includes a second prism lens array 11 on the surface facing the first lens sheet 9, as shown in FIG. Examples of the second prism lens array 11 include a triangular prism lens, a round prism lens, and a lenticular lens, but FIG. 12 illustrates the case of a round prism lens.
Like the lens array 19 in the first embodiment, the second prism lens array 11 is set to shift the peak of light emitted in the horizontal direction from the lighting device 3 toward the driver's seat and the passenger's seat. It is done.

  The diffusive sheet 9 is disposed to suppress the generation of moire interference fringes generated between the second lens sheet 10 and the image display element 2. The diffusive sheet 9 may have a polarization separation and reflection function.

The image display element 2 is preferably an element that transmits / blocks light in pixel units to display an image. As long as light is transmitted / blocked in pixel units to display an image, the lighting device 3 of the present embodiment effectively uses light whose luminance to the observer F side is improved, and the image quality is improved. A high image can be displayed.
The image display element 2 is preferably a liquid crystal display element. A liquid crystal display element is a typical element that transmits / blocks light in pixel units to display an image, and can improve image quality and reduce manufacturing costs as compared to other display elements. Can.

The lighting device 3 of the present embodiment is a backlight for the display device 1 provided as a car navigation system of a car.
FIG. 16 is a schematic view showing an actual arrangement of the display device 1.
The display device 1 is normally disposed at the center of a dashboard 31 of a car, as shown in FIG. This is to see from the driver's seat and the passenger's seat. Therefore, the display device 1 is less likely to be viewed from the front in the horizontal direction of the screen, and is viewed obliquely. Since the illumination device for the conventional display device shown in FIG. 13 is designed to be viewed from the front, it is designed to have the highest luminance in the front direction.

  Therefore, as a result of intensive investigations by the present inventors, the second lens sheet 10 is further arranged to shift the peak of light emitted in the horizontal direction from the lighting device 3 toward the driver's seat and the passenger's seat. I found out what I could do.

  In the present embodiment, when the second prism lens array 11 constituting the second lens sheet 10 has a round prism shape, the peak position is shifted in the wide-angle direction as the apex angle of the round prism is smaller. On the other hand, as the radius of curvature of the round prism is increased, light can be emitted also in the front direction while expanding the visual field in the oblique direction. Therefore, flat luminance distribution in a wide viewing angle range as shown in Example 1 is obtained. You can get it.

In the present embodiment, the aspect ratio of the second prism lens array 11 is preferably in the range of 30% to 70%. In the case of 30% or less, the horizontal visual field can not be greatly expanded. On the other hand, if it exceeds 70%, the luminance peak in the horizontal field of view becomes too wide.
In the case where the second prism lens array 11 is particularly a round prism lens 11, the prism apex angle is preferably in the range of 60 degrees to 100 degrees. The curvature radius at the top is preferably in the range of 20% to 50% of the lens width of the prism lens array 11.

FIG. 13 is a horizontal direction cross-sectional luminance distribution of the lighting device 3.
In the graph shown in FIG. 13, the front (0 degree) direction is normalized to 100%. Here, as a comparative example, a conventional illumination apparatus having a luminance peak in the front direction, an example 1 as the illumination apparatus in the first embodiment in which the horizontal field of view is expanded compared to the conventional while having a luminance peak in the front direction. The example which shifted the brightness | luminance peak to the driver's seat and 2nd passenger seat direction in 2 embodiment is shown.

  As shown in FIG. 13, the horizontal luminance distribution of the lighting apparatus 3 according to the first embodiment has almost the same luminance distribution as in the conventional lighting apparatus in the field of ± 30 degrees while having the luminance peak in the front direction It can be seen that the horizontal viewing angle is greatly expanded. On the other hand, in the horizontal luminance distribution of the lighting device 3 according to the second embodiment, since the luminance peak is in the direction of about 30 degrees, the lighting design actually looks brightest from the driver's seat and the passenger's seat.

FIG. 14 shows the normalized luminance distribution when the front luminance of the comparative example is 100%.
Similar to FIG. 13, the front luminance of Example 1 is almost equal to the front luminance of the comparative example, but the luminance is increased by about 10% in a field of view inclined at 3 ° or more and 10 ° or less which is a practical visual field range. You can see what you are doing. In addition, as described above, when the black louver structure according to Patent Document 2 is used, a decrease in luminance close to that of the comparative example by about 30% is expected.
The illumination device 3 according to the present embodiment reduces the reflected light to the front glass 30 by controlling the field of view by the lens, not by absorption, so that it is possible to provide the high-brightness display device 1 which is unprecedented.

As in the first embodiment described above, the display device 1 according to the present embodiment has a luminance peak inclined in the range of 3 ° to 10 ° from the normal direction in the screen vertical direction, and the half value in the screen vertical direction Since the corners are narrower as compared with the conventional lighting device as shown in FIG. 14, it is possible to sufficiently suppress the light emitted to the angle to be reflected on the windshield 30 as shown in FIG.
In addition, since the display device 1 of the present embodiment has a luminance distribution in the direction of the driver's seat F1 and the assistant driver's seat F2 in the horizontal direction of the screen, as shown in FIG. Are designed to make people look brightest.

As mentioned above, although the illuminating device 3 of this invention and the display apparatus 1 were demonstrated, the illuminating device 3 of this invention is not limited only to the display apparatus 1. FIG.
That is, it is not difficult to imagine that the present invention can also be applied to, for example, lighting equipment as the lighting device 3 having a function of efficiently condensing the light emitted from the light source 6.

DESCRIPTION OF SYMBOLS 1 ... Display apparatus 2 ... Image display element 3 ... Lighting apparatus 5 ... Reflection plate (reflection sheet)
6 light source 7 light guide 7a light deflection surface 7a
7b ... morphism exit surface 7L ... entrance face 8 ... first lens sheet 9 ... diffusing sheet 10 ... second lens sheet 18 ... light deflection elements 18a ... reflecting surface (one oblique side)
18b ... slope (the other side)
19: Lens array 20: Prism lens

Claims (11)

An in-vehicle display device provided with a lighting device,
The lighting device is
A translucent light guide having a substantially rectangular shape in a plan view and a second main surface that is an emission surface facing the first main surface and the first main surface;
A light source disposed to face the incident surface of the light guide;
A first lens sheet disposed on the second main surface side of the light guide;
Diffuse sheet,
Equipped with
Of the side end surfaces connecting the first main surface and the second main surface, a surface of the light guide that extends in the X direction is the incident surface.
A concave or convex light deflecting element is formed on the first main surface of the light guide for deflecting light incident from the incident surface and guided in the light guide toward the second main surface. ,
The light deflection element of the light guide is formed of a reflective surface and an inclined surface so that the cross-sectional shape orthogonal to the X direction is substantially triangular, and a reflective surface capable of directly reflecting light incident from the light source Is set within a range of 1 ° to 10 ° with respect to the first main surface,
Wherein the second major surface of the lightguide, the lens array is provided which extends in the Y direction as a normal direction of the incident surface of the light guide,
Wherein the first lens sheet, the second major surface opposite to the surface of the light guide extends in the entrance surface substantially parallel direction of the light guide, in a direction orthogonal to the extending direction The apex angle is 50 ° or more and 70 ° so that the emission light peak from the first lens sheet is inclined in the range of 3 ° or more and 10 ° or less with respect to the normal direction of the emission surface of the first lens sheet An on-vehicle display device comprising a prism lens set in the following range. In the lighting device,
Concave or convex of the light deflection elements are formed on the first major surface of the lightguide, angle the inclined surface in a substantially triangular shape in the direction normal to the cross section of the incident surface makes with the first major surface The vehicle-mounted display device according to claim 1, wherein the angle is within the range of 40 ° to 70 °. In the lighting device,
The light deflection elements are formed on the first major surface of the lightguide, to claim 1 or claim 2, characterized in that said the incident surface and substantially triangular prism lens extending in parallel Vehicle-mounted display device as described. In the lighting device,
Vehicle display device according to claim 1 or claim 2, characterized in that the light deflection elements are formed on the first major surface of the light guide is a dot shape interspersed each independently . In the lighting device,
The light deflection elements are formed on the first major surface of the light guide is concave or convex dot shape, each of which is independently disposed,
The light deflection element density D, which represents the number of light deflection elements present per unit area, decreases and then increases as the distance from the incident surface increases in the Y direction,
When the distance between the incident surface and the surface facing the incident surface is L, the position at which the light deflection element density D is minimum is in the range of L / 10 to 4 × L / 10 from the incident surface. The on-vehicle display device according to claim 4, wherein the on-vehicle display device is set. In the lighting device,
The arrangement pattern of the light deflection element is divided into a plurality of areas in the Y direction,
In the same area, the arrangement pitch of the light deflection elements in the X direction is substantially constant,
The arrangement pitch of the light deflection elements in the Y direction is minimized such that the light deflection element density D increases as the distance from the incident plane increases from the incident plane to the position where the light deflection element density D is minimized. from the position to the surface that faces the incident surface is changed to be smaller as away is from the incident surface,
Between the plurality of regions, the arrangement pitch of the light deflection elements in the X direction changes discontinuously and the region further away from the incident surface is the region up to the position where the light deflection element density D becomes minimum. Between the region from the position where the light deflection element density D is minimum to the surface facing the incident surface,
6. The in-vehicle display device according to claim 4, wherein an arrangement pitch of the light deflection elements in the Y direction varies discontinuously between the regions. In the lighting device,
Lens array formed on said second major surface of the lightguide, an aspect ratio of 2% to 60% or less of the lenticular lens array, 1 to claim, characterized in that a prism lens array or round prism array, The display apparatus for vehicles in any one of 6. In the lighting device,
The in-vehicle display device according to any one of claims 1 to 7, further comprising a reflective sheet at a position facing the first main surface of the light guide. In the lighting device,
The in-vehicle display device according to claim 8, wherein the reflection sheet is a specular reflection sheet. In the lighting device,
A second lens sheet is further provided between the first lens sheet and the diffusive sheet,
A round prism or a lenticular lens extending in a direction substantially normal to the light incident surface of the light guide is formed on the surface of the second lens sheet facing the first lens sheet. An in-vehicle display device according to any one of claims 1 to 9, characterized by: A lighting device according to any one of claims 1 to 10.
And images display element define a display image in accordance with the transmission / light shielding for each pixel,
An on-vehicle display device comprising: