TW201903465A - Head-up display illumination system using polarized light converter converting a non-polarized light source into a single-characteristic polarized light source for illumination of a liquid crystal display - Google Patents

Abstract

A high-efficiency head-up display illumination system using a polarized light converter is capable of converting a non-polarized light source into a single-characteristic polarized light source for illumination of a liquid crystal display, thereby improving efficiency and reducing power consumption. The structure mainly includes a polarized light birefringent lens disposed in front of a light emitting unit, and configured to divide non-polarized collimated light emitted from the light emitting unit into P-polarized light and S-polarized light to be emitted at different angles; a microlens array configured to concentrate and refract the P-polarized light and the S-polarized light to emit them in the same direction in a symmetrical side-by-side manner; and a polarized light conversion lens configured to convert all of the light into polarized light of the same nature and introduce the light to a liquid crystal display for display. Thereby, an excellent and high efficiency light source can be obtained.

Description

 High efficiency head-up display illumination system using a polarized light converter  

The invention relates to a high efficiency head-up display illumination system using a polarization converter, in particular to a polarized light source used in an automobile and capable of converting a non-polar light source into a single characteristic for liquid crystal display illumination. Improve efficiency and reduce power consumption.

The Head Up Display (hereinafter referred to as HUD) is composed of a virtual projection system box and a combiner. It was installed on the fighter aircraft at an early stage, and the pilot can simultaneously view the front scene through the optical synthesizer. The virtual image information projected by the device does not have to look down at the instrument panel. Due to the continuous advancement of technology, the more advanced automobile industry has gradually adopted the HUD system, and in the HUD system, how to reduce the waste of the light source and provide sufficient brightness, Reducing power consumption, reducing heat dissipation requirements, and reliability of the HUD system are particularly important in the harsh environmental conditions of the vehicle system. Therefore, the design of HUD's lighting system needs to be carefully researched and developed to take it to the next level.

The conventional head-up display illumination system, as shown in Figures 7 and 8, includes: a plurality of illumination sources 60, each of which is formed by a light-emitting diode 602 covered by a light-collecting cup 601. After the light emitting diode 602 emits the light source, the light is emitted outward through the collecting cup 601; since the light emitting diode 602 is a small area of the Lambertian light source, the luminous intensity and the light emitting angle are cosine functions. (cosine) relationship, and the function of the collecting cup 601 is to condense the diffused light source of the light emitting diode 602 to form a small angle with directivity, which is closer to the large area of the parallel light (the exit size of the collecting cup) and the direct light source. .

A light guide 61 is configured to accommodate the light source 60. The light guide column is a hollow cylinder with a high reflectivity mirror surface. In the present case, the lower side is the light incident surface, and the upper side is the light emitting surface. The light from the light source 60 can be mixed through the light emitted from each of the collecting cups 601 to achieve uniform mixing, and the light is emitted in the direction of the light emitting surface of the light guiding rod 61.

A diffusion sheet 62 is disposed at the other end of the light guiding rod 61 (ie, the light emitting surface), and the effect of adding the diffusion sheet 62 is to diffuse the light emitted from the light emitting surface of the light guiding column 61 to an appropriate angle to form a uniform surface light source. A backlight used to fill the rear LCD panel 63 constitutes a conventional illumination system.

However, in the conventional technology, the illuminating source 60 is covered with a illuminating cup 601 by a illuminating diode 602, and the light is reflected forward, and the energy is consumed, and the diffusing film 62 is added, although the illumination light can be changed. Evenly soft; but the angle will spread, it is difficult to concentrate on a specific angle (the angle of view of the HUD) and the visible range of the HUD (Eye-box), which causes a waste of luminosity in the use of the HUD, and the conventional illumination The system absorbs more than half of the light energy through the polarizer in the rear liquid crystal display, which further weakens the intensity of the light source, and the light is easily spread and is not easy to concentrate. It is a common shortcoming of the application, so the HUD needs a better lighting system to make the HUD Improve quality and be more competitive.

The main purpose of the present invention is mainly to abandon the arrangement of the conventional diffusion sheet, eliminating the waste of energy and reducing the brightness. A newly designed illumination system is mainly provided with a polarized light birefringent sheet in front of the light-emitting unit. The non-polar polarized light incident by the light-emitting unit is divided into P-polarized light and S-polarized light, and respectively emitted by different angles; and then a set of microlens arrays is used to make P-polarized light and S-polarized light. After being concentrated and refracted, they are emitted in the same direction and in a side-by-side symmetrical manner; and after a polarizing-converting plate-polarizing light conversion unit, the light is completely formed into a polarized light of the same nature, and then introduced into a liquid crystal display for image display, which can be excellent. High efficiency light source.

In order to achieve the above object, the preferred embodiment of the present invention can be achieved in the following manner:

a light-emitting unit is disposed to emit a strong light beam toward the front; and a collimating lens is arranged in front of the light-emitting unit; and a polarized light birefringent film is received to receive the light incident from the light-emitting unit and the collimating lens, and The incident non-polar polarized light is divided into P polarized light and S polarized light, and respectively emitted from different angles; a set of microlens arrays receives the input of P polarized light and S polarized light, including There are two lens array faces disposed opposite to each other, and the opposite lens array faces are symmetrically arranged with each other, and each of them is formed with a plurality of continuous and closely arranged lens units, so that P-polarized light and S-polarized light are transmitted through the lens unit. The concentrating and refracting, the lens unit entering the second lens array surface symmetrically left and right, and the corresponding lens unit on the second lens array surface can change the direction of each light beam, so that the P polarized light and S polarized light is emitted in the same direction and side by side; a polarized light conversion sheet is disposed on the light exiting side of the microlens array, and the polarizing conversion sheet is provided with an equally spaced coating layer to form a phase a late-polarized polarization conversion region and an unactuated light-transmitting region, wherein the polarization conversion region and the light-transmitting region are respectively aligned with the lens unit in the microlens array, and a set of polarization conversion regions and light transmission regions each occupy a microlens array Half of the area of each lens unit; when the light passes through the polarizing converter, it forms polarized light of the same nature for liquid crystal display; because there is no diffuser, the measurement can improve the penetration of the liquid crystal display. The rate (general specification ~5%) is 1.3~2 times, which gives stronger effective light.

 [Use]  

60‧‧‧Light source

601‧‧‧Spotlight

602‧‧‧Lighting diode

61‧‧‧Light guide

62‧‧‧Diffuser

63‧‧‧ panel

 〔this invention〕  

10‧‧‧Lighting unit

11‧‧‧ Collimating lens

20‧‧‧ Polarized birefringent film

30‧‧‧Microlens array

30'‧‧‧Microlens Array

31‧‧‧ lens array surface

31A‧‧‧Half block

31'‧‧‧ lens array surface

310‧‧‧ lens unit

32‧‧‧ lens array surface

32A‧‧‧Half block

32'‧‧‧ lens array surface

320‧‧‧ lens unit

40‧‧‧ polarized converter

41‧‧‧ polarized light conversion zone

42‧‧‧Transparent area

50‧‧‧LCD display

L‧‧‧Light

Ls‧‧‧Light

Lp‧‧‧Light

Figure 1 is a schematic view of the planar structure of the present invention.

Figure 2 is a schematic view of the three-dimensional structure of the present invention.

Fig. 3 is a structural view of a polarizing converter of the present invention.

Figure 4 is a schematic view showing the structure of a second embodiment of the microlens array of the present invention.

Fig. 5 is a schematic view showing the structure of a third embodiment of the microlens array of the present invention.

Figure 6 is a schematic illustration of an embodiment of the present invention used in parallel.

Figure 7 is an exploded view of the light source system of a conventional head-up display.

Figure 8 is a cross-sectional view of a light source system of a conventional head-up display.

Please refer to FIG. 1 and FIG. 2, wherein FIG. 1 is a plan view of a unit structure of the present invention, and FIG. 2 is a perspective view of a unit structure of the present invention. The present invention at least includes:

The light-emitting unit 10 is a white light-emitting diode (LED) that emits strong light, and can emit the strong light L emitted to the front; and the light-emitting unit 10 is composed of a single light source as shown in FIGS. 1 and 2, and can also be As shown in Fig. 6, a plurality of light emitting diodes are used; however, in order to enable the light to be emitted in parallel in the forward direction, one or a plurality of collimating lenses 11 may be disposed in front of the light emitting unit 10, and the collimating lens 11 The number of optical components can be increased according to actual needs. Usually, both performance and space requirements are designed. One or two are common modes, but the drawing is only one.

A polarized birefringent plate 20 receives the light L incident from the light-emitting unit 10 and the collimator lens 11, and divides the incident non-polar polarized light L into P-polarized light and S-polarized light Lp, Ls, And they are shot from different angles.

A set of microlens arrays 30 are received by the P-polarized light and the S-polarized light, and are transparent block-shaped structures, and are disposed opposite to each other on the light-incident surface and the light-emitting surface which are disposed in parallel with each other. The lens array faces 31, 32 are respectively formed with a plurality of consecutive and closely arranged lens units 310, 320 on the lens array faces 31, 32; wherein the lens units 310, 320 shown in Fig. 2 are a plurality of closely juxtaposed square cells; The two lens array faces 31 and 32 of the microlens array 30 can provide light Lp and Ls directly through the light-transmitting material; and the microlens array 30 can be integrally formed from a transparent material, and will be more manufactured and combined. Convenient; as in the microlens array 30 embodiment shown in Figures 1 and 2, the two lens array faces 31, 32 of the microlens array 30 are opposite to each other by lens units 310, 320, respectively. Lp and Ls are collected and projected onto the lens unit 320 corresponding to the lens array surface 32, and the lens unit 320 changes the direction of each light beam so that the P-polarized light and the S-polarized light are emitted in the same direction and in a side-by-side symmetrical manner.

Referring to Figures 1, 2 and 3, a polarizing converter 40 is disposed on the light exiting side of the microlens array 30. The polarizing converter 40 is provided with an equally spaced coating to form a phase delay. The characteristic polarization conversion region 41 and the unactuated light transmission region 42, the polarization conversion region 41 and the light transmission region 42 are respectively aligned with the lens units 310, 320 in the microlens array 30, and a set of polarization conversion regions 41 and light transmission. The regions 42 each occupy half of the area of each lens unit 310, 320 in the microlens array 30; and the cladding of the polarization conversion region 41 has a half-wave plate characteristic, and the phase delay axis of the cladding The polarization direction of the polar apolar light is at an angle of 45 degrees or 135 degrees.

Referring to Figures 1 and 2, the present invention emits a strong light L emitted from the light-emitting unit 10 to the front, and the light can be emitted forward by the collimator lens 11 when the light L passes through the polarized light birefringent film. 20, the incident non-polar polarized light L is divided into P polarized light and S polarized light Lp, Ls, when the two polarized rays Lp, Ls enter the microlens array 30, first enter the first In the lens unit 310 of the lens array surface 31, the P-polarized light and the S-polarized light ray Lp, Ls are condensed and refracted by the lens unit 310, and enter the lens unit 320 of the second lens array surface 32 in a left-right cross-symmetric manner. The lens unit 320 can change the direction of each beam so that the P-polarized light and the S-polarized light are emitted in the same direction and in a side-by-side symmetrical manner; since the lens unit 320 is both opposite to the polarization conversion region 41 on the polarization conversion sheet 40 and the unactuated The light-transmitting region 42 corresponds to each other. Therefore, when the first polarized light Ls enters the lens unit 320, it enters the light-transmitting region 42 of the polarizing converter 40 and is incident on the liquid crystal display 50; and the second polarized light Lp enters. After the lens unit 320, the polarization conversion of the polarization conversion sheet 40 is incident. 41, the original polarized light Lp is converted into another polarized light Ls, and then injected into the liquid crystal display 50; then all the emitted light can be converted into the same nature of the S polarized light Ls, for the liquid crystal display 50 display image.

The collimating lens 20 disposed in front of the light source group 10 may be a single lens group (which may include one or a plurality of optical elements) or a lens array composed of a plurality of collimating lenses, which are closely juxtaposed and connected to each other. A wide range of illumination surfaces, but which are well-known to those skilled in the art, can be easily handled in accordance with the present invention, and will not be further described in the drawings; please refer to the microlens array 30 shown in Figures 1 and 2 for space saving or material saving. In consideration of factors, as in the embodiment shown in FIG. 4, the equivalent substitution is a microlens array 30' composed of two half blocks 31A, 32A having one lens unit 310, 320, and the two half blocks 31A, The 32A is a two-symmetric lens array, and each of the lens units 310 and 320 are respectively formed on the outer side to form a plurality of continuous and closely arranged lens units 310, and the same effect can be achieved.

Referring to the microlens array 30 shown in FIG. 2, the lens units 310, 320 on the front and rear lens array surfaces 31, 32 of the microlens array 30 are a plurality of rectangular lenses, and can collect an appropriate amount of light to be projected on the polarization conversion sheet 40. The position of the polarization conversion region 41 or the light transmission region 42; but under the premise that the light-emitting unit 10, the collimator lens 11, the polarization-polar birefringent plate 20, and the polarization conversion sheet 40 are unchanged, the microlens array 30 The microlens array 30' can be changed as shown in Fig. 5, and the lens units 310', 320' on the front and rear lens array faces 31', 32' of the microlens array 30' are an elongated cylindrical lens. Corresponding to the position of the polarization conversion region 41 or the light transmission region 42 of the polarization conversion sheet 40, the intended effect can also be achieved.

Referring to FIG. 6, when the present invention is implemented, it can be juxtaposed into a densely distributed light source for projection, and one (or several) collimating lens arrays 11 can be used to reduce the thickness of the illumination system. Improve the transmittance of the liquid crystal display (general specification ~ 5%) 1.3 to 2 times, to obtain a stronger effective light illumination system.

When using the present invention, it will have the following advantages:

1. Since the present invention does not have a diffuser arrangement as conventionally used, the light source is not consumed in a large amount, so the brightness can be improved and energy can be saved.

2. Since the present invention firstly projects light with a white light source group, and uses the polarized light birefringent sheet to split the incident non-polar polarized light into P-polarized light and S-polarized light, and respectively emitted from different angles; After the microlens array and the polarization conversion sheet are separated and corresponding, and then used for the liquid crystal display, the transmittance of the liquid crystal display can be improved by 1.3 to 2 times by the measurement, and a stronger effective light is obtained.

3. The invention can be implemented by placing a strong white LED light source on the optical axis, which is simpler and more practical and saves cost.

The above-mentioned structures are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention; therefore, equivalents or modifications may be made without departing from the invention. Equivalent changes and modifications made in the spirit and scope, such as the addition of other accessories, or slight changes in the composition or quantity of the lens, or changes in the material, but the overall architecture is unchanged, should be covered by the features of the present invention.

Claims (9)

 A high-efficiency head-up display illumination system using a polarized light converter, the structure comprising at least: a light-emitting unit capable of emitting a strong light emitted forward; and a collimating lens disposed in front of the light-emitting unit; The refracting sheet receives the light incident by the illuminating unit and the collimating lens, and divides the incident non-polar polarized light into P-polarized light and S-polarized light, and is respectively emitted by different angles; The array is configured to receive the P-polarized light and the S-polarized light, and is a transparent block-shaped structure, and respectively disposed on the light-incident surface and the light-emitting surface which are disposed in parallel with each other, and are respectively provided with opposite lens array surfaces. Each of the lens array faces is formed with a plurality of continuous and closely arranged lens units, so that the P-polarized light and the S-polarized light are concentrated and refracted by the first lens unit, and enter the second lens in a left-right cross-symmetry. Each corresponding lens unit in the array surface; each corresponding lens unit on the second lens array surface can change the direction of each light beam, so that the P polarized light and the S polarized light are in the same square And a side-by-side manner; a polarizing converter is disposed on the light-emitting side of the lens array, and the polarizing converter is provided with an equally spaced coating layer to form a polarization conversion region with phase retardation characteristics and an unactuated light-transmitting region. The polarization conversion region and the light transmission region are respectively aligned with the lens unit in the microlens array, and a set of polarization conversion regions and light transmission regions each occupy half of the area of each lens unit in the microlens array; when the light passes through the polarization After the conversion sheet, polarized light of the same nature is formed for the liquid crystal display to be imaged.    The high-efficiency head-up display illumination system using the polarization converter according to claim 1, wherein the lens unit on the surface of the lens array of the microlens array is an elongated cylindrical lens, which corresponds to the polarization conversion sheet. The position of the polarization conversion region and the light transmission region.    The high-efficiency head-up display illumination system using a polarization converter as described in claim 1, the microlens array is integrally formed.    The high-efficiency head-up display illumination system using a polarization converter according to claim 1, wherein the microlens array is composed of two half blocks having a lens unit, and the two half system is two. The symmetrical block lenses are respectively formed on the outer side to form a plurality of continuous and closely aligned and aligned lens units.    A high-efficiency head-up display illumination system using a polarization converter as described in claim 1, wherein the illumination unit is a single light source, and the collimation lens is only one set.    A high efficiency head-up display illumination system using a polarization converter as described in claim 1, wherein the collimating lens is an array of a plurality of components.    A high-efficiency head-up display illumination system using a polarization converter as described in claim 1, wherein the illumination unit comprises two or more.    A high-efficiency head-up display illumination system using a polarization converter as described in claim 1, wherein the illumination unit is a light-emitting diode.    The high-efficiency head-up display illumination system using the polarization converter according to claim 1, wherein the polarization conversion region on the polarization conversion sheet has a half-wave phase delay characteristic, and the phase delay axis of the polarization conversion sheet is The polarization direction of the polar apolar light is at an angle of 45 degrees or 135 degrees.