JP2010277065A - Headup display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a headup display device capable of displaying a virtual image with high luminance. <P>SOLUTION: The headup display device 11 displays the virtual image V with display light L emitted from a liquid crystal display 15 including a liquid crystal display panel 18 and a light emitting element 22 for transmitted illumination of the liquid crystal display panel 18. The liquid crystal display 15 includes a condenser lens 21 condensing illumination light emitted from the light emitting element 22, and an optical member 20 having lenticular lenses 20a and 20b spreading the illumination light condensed by the condenser lens 21. The lenticular lenses 20a and 20b have such shape that space to refract parallel beams at an integer multiple of a predetermined angle is gradually reduced or extended. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid crystal display panel and a head-up display device that displays a virtual image by display light emitted from a liquid crystal display having a light emitting element such as a light emitting diode that transmits and illuminates the liquid crystal display panel.

  Conventionally, various head-up display devices using a liquid crystal display have been proposed, and for example, disclosed in Patent Document 1. Such a head-up display device 1 projects display light L onto a transflective plate called a vehicle windshield or combiner to display a virtual image. The head-up display device 1 has a liquid crystal display 4 and a reflecting mirror 5 housed in a housing 3 having a translucent window 2, and the display light L emitted from the liquid crystal display 4 is reflected by the reflecting mirror 5. And projected onto the windshield or transflective plate. The liquid crystal display 4 includes a liquid crystal display panel 6 and a light emitting element 7 such as a light emitting diode that transmits and illuminates the liquid crystal display panel 6.

Japanese Patent Laid-Open No. 11-310055

However, since the illumination light emitted from the light emitting element 7 is transmitted through the liquid crystal display panel 6 and spreads over a range larger than the viewpoint range called an eyebox, the illumination light is wasted and a virtual image to be displayed is displayed. Had the problem of low brightness.
The present invention has been made in view of this problem, and provides a head-up display device capable of displaying a virtual image with high luminance.

  In order to solve the above problems, the present invention provides a head-up display that displays a virtual image V by display light L emitted from a liquid crystal display 15 having a liquid crystal display panel 18 and a light emitting element 22 that transmits and illuminates the liquid crystal display panel 18. In the device 11, the liquid crystal display 15 includes a condenser lens 21 that condenses the illumination light emitted from the light emitting element 22, and a lenticular lens 20 a that spreads the illumination light condensed by the condenser lens 21. , 20b, and an optical member 20.

  In the present invention, the lenticular lenses 20a and 20b have a shape in which the interval at which parallel light is refracted at an integral multiple of the predetermined angle α is gradually reduced or enlarged.

  In the present invention, the lenticular lenses 20a and 20b are multifaceted.

  In the present invention, the lenticular lenses 20a and 20b are composed of a plurality of curved surfaces.

  Further, according to the present invention, the liquid crystal display 15 includes a second condensing lens 19 that condenses the illumination light spread by the optical member 20.

  Further, according to the present invention, the liquid crystal display 15 includes cylindrical members 50, 51a, 51b, 51c, 51d, 52a, 52b whose inner walls are mirror surfaces at least between the condenser lens 21 and the lenticular lens 20. It is what has.

  Corresponding to the eye box, it is possible to collect the illumination light emitted from the light emitting element and to transmit and illuminate the liquid crystal display panel, thereby displaying a virtual image with high luminance.

Sectional drawing which shows 1st embodiment of this invention. The outline figure of the head up display which shows 1st embodiment same as the above. The front view and rear view of the optical member which show 1st embodiment same as the above. The principal part enlarged view of the optical member which shows 1st embodiment same as the above. The principal part enlarged view of the optical member which shows 2nd embodiment of this invention. The principal part enlarged view of the optical member which shows 3rd embodiment of this invention. The principal part enlarged view of the optical member which shows 4th embodiment of this invention. The principal part enlarged view of the optical member which shows 5th embodiment of this invention. The principal part enlarged view of the optical member which shows 6th embodiment of this invention. Sectional drawing which shows 7th embodiment of this invention. Sectional drawing which shows other embodiment of this invention. Sectional drawing which shows other embodiment of this invention. Sectional drawing which shows a prior art example.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. 1 to 4 show a first embodiment.
The head-up display device 11 is disposed in the dashboard 12 of the vehicle (see FIG. 2). The display light L projected by the head-up display device 11 is reflected by the windshield 13 to the vehicle driver 14. The vehicle driver 14 can visually recognize the virtual image V superimposed on the landscape.

  The head-up display device 11 has a liquid crystal display 15 and a reflector 16 accommodated in a housing 17. The liquid crystal display 15 includes a liquid crystal display panel 18, a condenser lens (second condenser lens) 19, an optical member 20, a condenser lens (condenser lens) 21, and a light emitting diode (light emitting element) 22. It will be. The lens group 23 includes a condenser lens 19, an optical member 20, and a condenser lens 21. The condensing lens 19 is composed of a convex lens having a toroidal surface in which the curvature in the vertical direction and the curvature in the horizontal direction are different.

  The liquid crystal display panel 18 has a polarizing plate attached to both front and rear surfaces of a liquid crystal cell in which liquid crystal is sealed in a pair of translucent substrates on which a transparent electrode film is formed, and is fixed to a case body 24. The case body 24 has a substantially rectangular tube shape, and the rear end portion of the case body 24 is fixed to a heat radiating member described later. A condenser lens 19, an optical member 20, and a condenser lens 21 are held at an intermediate portion of the case body 24, and a liquid crystal display panel 18 is held at a front end portion. Illumination light emitted from the light emitting diode 22 is converted into parallel light having a substantially uniform light density by the condenser lens 21, and illuminates the liquid crystal display panel 18 through the optical member 20 and the condenser lens 19. The light emitting diode 22 is mounted on the circuit board 27.

  The reflector 16 includes a concave mirror 30, a holding member 31, and a stepping motor 32. The concave mirror 30 is formed by depositing a metal (for example, aluminum) on a resin (for example, polycarbonate) to form a reflective surface 30a. The reflective surface 30a is a concave surface, and the display light L emitted from the liquid crystal display 15 is enlarged to display the virtual image V. The concave mirror 30 is bonded to the holding member 31 with a double-sided adhesive tape. The holding member 31 is made of resin (for example, ABS), and the gear portion 34 and the shaft portion 35 are integrally formed. The shaft portion 35 of the holding member 31 is pivotally supported by the housing 17.

  A gear 37 is attached to the rotation shaft of the stepping motor 32, and the gear 37 is engaged with the gear portion 34 of the holding member 31. The concave mirror 30 is supported so as to be rotatable together with the holding member 31, and the projection direction of the display light L can be adjusted by rotating the concave mirror 30 by the stepping motor 32. The vehicle driver 14 operates a push button switch (not shown) to adjust the angle of the concave mirror 30 so that the display light L is reflected at the eye position (that is, the virtual image V can be visually recognized).

  Reference numeral 40 denotes a heat radiating member, and the heat radiating member 40 is disposed in the opening 17 a of the housing 17. The heat radiating member 40 is fixed to the housing 17 by a flange portion 40a with a screw (not shown). The heat dissipating member 40 has a large number of flat heat dissipating fins 40 b and releases heat generated by the light emitting diodes 22 to the outside of the housing 17. Reference numeral 42 denotes a rectangular annular packing member, and the packing member 42 prevents the dust from entering the housing 17 by closing the space between the heat radiating member 40 and the opening 17 a of the housing 17.

  The housing 17 accommodates the liquid crystal display 15 and the reflector 16. The housing 17 is provided with a window portion 44 from which the display light L is emitted. The window portion 44 is made of a translucent resin (for example, acrylic) and has a curved shape. The housing 17 is provided with a light shielding wall 17c, which prevents a phenomenon (washout) in which external light such as sunlight enters the liquid crystal display 15 and makes the virtual image V difficult to see. The light shielding wall 17 c has a flat plate shape and is formed so as to hang obliquely from the upper part of the housing 17.

Next, the optical member 20 will be described in detail with reference to FIG. The optical member 20 includes a lens portion 20a formed on the rear surface side (light emitting element 22 side) and a lens portion 20b formed on the front surface side (liquid crystal display panel 18 side). The illumination light collected by the condenser lens 21 is spread in the vertical direction and the horizontal direction.
The lens portion 20a of the optical member 20 is composed of a lenticular lens extending in the horizontal direction, and spreads the illumination light collected by the condenser lens 21 in the vertical direction. The lens portion 20b of the optical member 20 is composed of a lenticular lens extending in the vertical direction, and spreads the illumination light collected by the condenser lens 21 in the horizontal direction.

  The parallel light P1 that is separated from the optical axis A of the lens parts 20a and 20b by a predetermined interval W1 is refracted at a predetermined angle α with respect to the optical axis A in the lens parts 20a and 20b, and is separated from the optical axis A by a predetermined interval W1 + W2. The parallel light P2 is refracted at a predetermined angle 2α with respect to the optical axis A in the lens units 20a and 20b, and the parallel light P3 separated from the optical axis A by a predetermined interval W1 + W2 + W3 Refraction is performed at a predetermined angle 3α with respect to A (see FIG. 4). The lens portions 20a and 20b have shapes in which the intervals W1, W2, and W3 for refracting parallel light at an integral multiple of the predetermined angle α are gradually reduced. That is, the intervals W1, W2, and W3 have a relationship of W1> W2> W3.

FIG. 5 shows a second embodiment. The second embodiment is different only in the shapes of the lens portions 20a and 20b, and the other configurations are the same as those of the first embodiment.
The parallel light P4 that is separated from the optical axis A of the lens portions 20a and 20b by a predetermined interval W4 is refracted at a predetermined angle α with respect to the optical axis A and is separated from the optical axis A by a predetermined interval W4 + W5. The parallel light P5 is refracted at a predetermined angle 2α with respect to the optical axis A in the lens portions 20a and 20b, and the parallel light P6 separated from the optical axis A by a predetermined interval W4 + W5 + W6 Refracted at a predetermined angle 3α with respect to A. The lens portions 20a and 20b have a shape in which the interval at which the parallel light is refracted by an integral multiple of the predetermined angle α gradually increases. That is, the intervals W4, W5, and W6 have a relationship of W4 <W5 <W6.
As a result, a uniform and equal amount of light can be given over the entire irradiation area, so that a display image with high display quality can be obtained with little luminance variation in each portion of the display image.

FIG. 6 shows a third embodiment. In the third embodiment, only the shapes of the lens portions 20a and 20b are different, and other configurations are the same as those in the first embodiment. The lens portions 20a and 20b have a plurality of planes Q1, Q2, Q3, and Q4. The inclination angles of the planes Q1, Q2, Q3, and Q4 are gradually increased.
Thereby, the light incident obliquely on the optical member 20 can also be controlled, a surface on which the light is uniformly irradiated can be provided, and unevenness of the display image can be reduced. In the second embodiment, only the parallel light can be controlled and the other light cannot be controlled. In the third embodiment, the oblique light can also be controlled.

FIG. 7 shows a fourth embodiment. In the fourth embodiment, only the shapes of the lens portions 20a and 20b are different, and other configurations are the same as those in the first embodiment. The lens portions 20a and 20b have a plurality of curved surfaces R1, R2, R3, and R4. Each curved surface R1, R2, R3, R4 has a convex lens shape, but may have a concave lens shape.
As a result, the light can be slightly expanded as compared with the case where each surface is a flat surface, and the range in which the light is uniformly irradiated can be expanded.

FIG. 8 shows a fifth embodiment. In the fifth embodiment, only the shapes of the lens portions 20a and 20b are different, and other configurations are the same as those in the first embodiment. The lens parts 20a, 20b have a plurality of planes S1, S2, S3, S4. The plane S1 is perpendicular to the optical axis, and the planes S2, S3, S4 are inclined surfaces. The inclination angles of the planes S2, S3, S4 are gradually increased.
Thereby, the light incident obliquely on the optical member 20 can also be controlled, a surface on which the light is uniformly irradiated can be provided, and unevenness of the display image can be reduced.

FIG. 9 shows a sixth embodiment. In the sixth embodiment, only the shapes of the lens portions 20a and 20b are different, and other configurations are the same as those of the first embodiment. The lens portions 20a and 20b have a plurality of curved surfaces R1, R2, R3, and R4. Each curved surface R1, R2, R3, R4 has a convex lens shape, but may have a concave lens shape.
As a result, the light can be slightly expanded as compared with the case where each surface is a flat surface, and the range in which the light is uniformly irradiated can be expanded. In the sixth embodiment, the range B2 in which light is homogeneous is larger than the range B1 in the fifth embodiment.

FIG. 10 shows a seventh embodiment. In the seventh embodiment, a cylindrical member 50 is provided in the liquid crystal display 15, and other configurations are the same as those in the first embodiment.
The cylindrical member 50 is composed of four glass mirrors and is attached to the inside of the case body 24 of the liquid crystal display 15. The cylindrical member 50 has a mirror surface on the inner wall, and is disposed between the condenser lens 21 and the optical member 20.
The cylindrical member 50 reflects light emitted obliquely from the condenser lens 21 and makes the light incident on the optical member 20 without leaving the light, so that light that is originally emitted obliquely and is not used as illumination light. Can be used as illumination light, more light can be obtained than before, and the efficiency is increased, so that the average luminance is increased.

  According to each embodiment, the illumination light emitted from the light emitting element is condensed in the vertical and horizontal directions by the condenser lens 21, and the condensed illumination light is spread in the vertical and horizontal directions by the optical member 20. Thus, the liquid crystal display panel 18 can be transmitted and illuminated so as to correspond to the eye box of the vehicle driver 14, and a high-quality virtual image V with high brightness and high uniformity can be displayed.

  The present invention is not limited to each embodiment, and various modifications are possible. For example, the lens portions 20a and 20b of the optical member 20 may be cylindrical surfaces. Further, four reflecting members 51a, 51b, 51c, 51d, which are mirror-deposited on a plate-shaped resin base material, may be attached to the inside of the case body 24 (see FIG. 11), or L-shaped. You may comprise a cylindrical member by the two reflection members 52a and 52b which gave mirror vapor deposition to the resin base material (refer FIG. 12).

DESCRIPTION OF SYMBOLS 11 Head-up display apparatus 15 Liquid crystal display device 17 Housing 18 Liquid crystal display panel 19 Condensing lens (2nd condensing lens)
20 Optical member 20a Lens part (lenticular lens)
20b Lens part (lenticular lens)
21 Condenser lens (Condenser lens)
22 Light Emitting Diode (Light Emitting Element)
23 lens group 50 cylindrical member 51a reflecting member (cylindrical member)
51b Reflective member (tubular member)
51c Reflective member (tubular member)
51d Reflective member (tubular member)
52a Reflective member (tubular member)
52b Reflective member (tubular member)
V Virtual image L Display light

Claims (6)

A head-up display device that displays a virtual image by display light emitted by a liquid crystal display panel and a liquid crystal display provided with a light emitting element that transmits and illuminates the liquid crystal display panel,
The liquid crystal display comprises: a condensing lens that condenses the illumination light emitted from the light emitting element; and an optical member having a lenticular lens that spreads the illumination light collected by the condensing lens. A head-up display device.   2. The head-up display device according to claim 1, wherein the lenticular lens has a shape in which the interval at which the parallel light is refracted at an integral multiple of a predetermined angle is gradually reduced or enlarged.   The head-up display device according to claim 1, wherein the lenticular lens has multiple surfaces.   The head-up display device according to claim 1, wherein the lenticular lens includes a plurality of curved surfaces.   The head-up display device according to claim 1, wherein the liquid crystal display includes a second condenser lens that collects the illumination light spread by the optical member.   The head-up display device according to claim 1, wherein the liquid crystal display includes a cylindrical member having an inner wall that is a mirror surface between at least the condenser lens and the lenticular lens.

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