CN114077065A

CN114077065A - Optical module and head-up display

Info

Publication number: CN114077065A
Application number: CN202111537678.XA
Authority: CN
Inventors: 马红虎; 李礼操; 刘风雷
Original assignee: Zhejiang Crystal Optech Co Ltd
Current assignee: Zhejiang Crystal Optech Co Ltd
Priority date: 2021-12-15
Filing date: 2021-12-15
Publication date: 2022-02-22

Abstract

An optical module and a head-up display relate to the technical field of optics. The optical module comprises an image generation unit and a reflector set which are arranged in sequence; the image generation unit comprises a light source and a display unit positioned on the light emitting side of the light source, light beams emitted by the light source output image signals after passing through the display unit, and the image signals are reflected to the front windshield of the automobile through a reflector group and are imaged on the front windshield; the reflective first polarizing film is arranged between the light source and the display unit and used for reflecting part of light beams emitted by the light source. The head-up display comprises the optical module. The optical module and the head-up display can reduce the temperature of the display unit.

Description

Optical module and head-up display

Technical Field

The invention relates to the technical field of optics, in particular to an optical module and a head-up display.

Background

With the development of vehicle-mounted electronic systems, a Head Up Display (HUD) has been widely used in some high-end vehicle models. The vehicle-mounted head-up display can project running information such as vehicle speed and kilometer values and the like at the lower left corner of the front windshield glass at any time when the vehicle-mounted head-up display runs, so that a driver does not need to look down to see the vehicle speed when running, and can easily see the vehicle in front at the head. The vehicle-mounted head-up display can well assist in driving, and driving experience of a driver is improved.

However, when the light beam emitted from the light source of the conventional optical module applied to the vehicle-mounted head-up display enters the display unit, the light beam emitted from the light source includes a light beam capable of being utilized by the display unit and stray light which cannot be utilized by the display unit, so that in order to ensure a sufficient effective light beam, the power of the light source needs to be increased, which results in an increase of the corresponding stray light. The increase of the stray light may cause the heat of the corresponding light beam to increase when the light source is incident into the display unit, which may cause the temperature of the display unit to increase greatly, and the high temperature may affect the imaging quality of the display unit, and may even cause the display unit to be damaged due to overheating.

Disclosure of Invention

The invention aims to provide an optical module and a head-up display, which can reduce the temperature of a display unit.

The embodiment of the invention is realized by the following steps:

in one aspect of the present invention, an optical module is provided, which includes an image generation unit and a mirror group sequentially disposed; the image generation unit comprises a light source and a display unit positioned on the light emitting side of the light source, light beams emitted by the light source output image signals after passing through the display unit, and the image signals are reflected to the front windshield of the automobile through a reflector group and are imaged on the front windshield; the reflective first polarizing film is arranged between the light source and the display unit and used for reflecting part of light beams emitted by the light source. The optical module can reduce the temperature of the display unit.

Optionally, the display unit is any one of a TFT-LCD, DLP, LCOS.

Optionally, when the display unit is a TFT-LCD or LCOS, the light transmission axis direction of the first polarizing film is identical to the light transmission axis direction of the polarizer at the incident end of the display unit.

Optionally, a transparent film is disposed on the reflector set, and the transparent film is used for transmitting infrared light and/or ultraviolet light incident to the reflector set from the front windshield; or, the transmission film is used for transmitting ultraviolet light and part of visible light which are incident to the reflector group from the front windshield.

Optionally, the transparent film is plated on the substrate of the mirror group, and the substrate of the mirror group on which the transparent film is disposed is made of glass.

Optionally, the optical module further includes a dust-proof film, the dust-proof film is located between the reflector set and the front windshield, and the dust-proof film is used for transmitting light beams emitted by the reflector set and guiding the light beams to the front windshield.

Optionally, the dustproof film comprises a substrate and a second polarizing film attached to the substrate.

Optionally, the mirror group comprises a first mirror located on the light-emitting side of the image generation unit and a second mirror located on the light-emitting side of the first mirror, and the second mirror is used for reflecting the light beam reflected by the first mirror to the front windshield.

Optionally, the reflective surface of at least one of the first mirror and the second mirror is a free-form surface.

Optionally, a transparent film is plated on the substrate of the first reflecting mirror or the second reflecting mirror, and the transparent film is used for transmitting infrared light and/or ultraviolet light incident to the reflecting mirror group from the front windshield; or, the transmission film is used for transmitting ultraviolet light and part of visible light which are incident to the reflector group from the front windshield; and the substrate of the reflector provided with the transmission film is made of glass.

Optionally, the optical module further comprises a package housing for packaging the image generation unit and the mirror group.

In another aspect of the invention, a head-up display is provided, which includes the optical module.

The beneficial effects of the invention include:

the optical module comprises an image generation unit and a reflector set which are arranged in sequence; the image generation unit comprises a light source and a display unit positioned on the light emitting side of the light source, light beams emitted by the light source output image signals after passing through the display unit, and the image signals are reflected to the front windshield of the automobile through a reflector group and are imaged on the front windshield; the reflective first polarizing film is arranged between the light source and the display unit and used for reflecting part of light beams emitted by the light source. This application is through setting up first polarizing film between the light-emitting side of light source and display element, like this, when the light beam of image generation unit's light source outgoing incides display element, can reflect through first polarizing film and fall the miscellaneous light that display element is not required, and then make effectual light beam incide to display element, like this, for prior art, this application can effectively reduce the miscellaneous light in the light source and cause the influence to display element, avoids display element overheated.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic diagram of an optical path of an optical module according to some embodiments of the present invention;

FIG. 2 is a second schematic optical path diagram of an optical module according to some embodiments of the present invention;

FIG. 3 is a third optical path diagram of an optical module according to some embodiments of the present invention;

fig. 4 is a schematic structural view of a dust-proof film according to some embodiments of the present invention.

Icon: 10-an image generation unit; 11-a first polarizing film; 21-a first mirror; 22-a second mirror; 23-a permeable membrane; 30-a receiving end; 40-dustproof film; 41-a substrate; 42-a second polarizing film; 60-front windshield.

Detailed Description

The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the invention and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the invention and the accompanying claims.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood that when an element such as a layer, region or substrate is referred to as being "on" or "extending" onto "another element, it can be directly on or extend directly onto the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or extending "directly onto" another element, there are no intervening elements present. Also, it will be understood that when an element such as a layer, region or substrate is referred to as being "on" or "extending over" another element, it can be directly on or extend directly over the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or extending "directly over" another element, there are no intervening elements present. It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

Relative terms such as "below …" or "above …" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe one element, layer or region's relationship to another element, layer or region as illustrated in the figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the figures.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Referring to fig. 1 or fig. 2, the present embodiment provides an optical module including an image generating unit 10 and a mirror group sequentially disposed; the image generating unit 10 comprises a light source and a display unit positioned at the light emitting side of the light source, light beams emitted by the light source output image signals after passing through the display unit, the image signals are reflected to the front windshield 60 of the automobile through a reflector group, and the image signals are imaged on the front windshield 60; a reflective first polarizing film 11 is disposed between the light source and the display unit, and the first polarizing film 11 is used for reflecting a part of light beams emitted by the light source. The optical module can reduce the temperature of the display unit.

The image generating unit 10 is provided for outputting an image signal, wherein the image signal may be formed by a light beam emitted by the light source passing through the display unit. The light source is arranged on the light incident side of the display unit.

Alternatively, the display unit may be any one of a TFT-LCD, DLP, LCOS.

Also, optionally, when the display unit is a TFT-LCD or LCOS, the light transmission axis direction of the first polarizing film 11 coincides with the light transmission axis direction of the polarizer at the incident end of the display unit.

The mirror group is used for reflecting the image signal, so that the light beam enters the front windshield 60 of the automobile after passing through the mirror group. The arrangement position of the image generation unit 10 relative to the front windshield 60 can be properly changed by arranging the reflector group, so that the arrangement position of the image generation unit 10 is more reasonable. The specific arrangement manner or arrangement position of the mirror group can be determined by those skilled in the art according to actual requirements, and the present application is not particularly limited.

Thus, the receiving end 30 can receive the virtual image formed in front of the front windshield 60 after the image signal emitted from the image generating unit 10 is reflected by the mirror group, and then the virtual image is received by the receiving end 30. In the present embodiment, the receiving end 30 is a human eye of a user.

In the present embodiment, a first polarizing film 11 is disposed between the light source and the display unit, as shown in fig. 1. Among them, the first polarizing film 11 serves to pass light beams that can be utilized by the display unit, while reflecting stray light that cannot be utilized by the display unit. Like this, when the light beam of image generation unit 10's light source outgoing incides to the display element, can reflect through first polarizing film 11 the unnecessary parasitic light of display element, and then make the light beam of inciding to the display element be effective light beam, so, for prior art, this application can effectively reduce the parasitic light in the light source and cause the influence to the display element, avoids the display element overheated (if parasitic light and effective light beam incide to the display element simultaneously, for only letting effective light beam incide to the display element, will certainly lead to the heat increase of display element). It should be understood that, in the present embodiment, the first polarizing film 11 should be selected such that the effective light beam is incident to the display unit and such that the stray light is reflected.

In addition, the first polarizing film provided by the present application is of a reflective type, and stray light that cannot be used can be reflected, so that heat generation can be further reduced.

It should be noted that, in order to ensure that the light beam incident on the display unit from the light source has sufficient intensity, the normal formation of the virtual image is not affected. The power of the light source can be increased appropriately. Specifically, those skilled in the art can set the setting according to actual requirements, and the application is not limited in particular.

In summary, the optical module provided in the present application includes an image generation unit 10 and a mirror group, which are sequentially disposed; the image generating unit 10 comprises a light source and a display unit positioned at the light emitting side of the light source, light beams emitted by the light source output image signals after passing through the display unit, the image signals are reflected to the front windshield 60 of the automobile through a reflector group, and the image signals are imaged on the front windshield 60; a reflective first polarizing film 11 is disposed between the light source and the display unit, and the first polarizing film 11 is used for reflecting a part of light beams emitted by the light source. This application is through setting up first polarizing film 11 between the light-emitting side of light source and display element, like this, when the light beam of image generation unit 10's light source outgoing incides display element, can reflect through first polarizing film 11 and fall the miscellaneous light that display element is not required, and then make effectual light beam incide to display element, like this, for prior art, this application can effectively reduce the miscellaneous light in the light source and cause the influence to display element, avoids display element overheated.

In addition, in this embodiment, the optical module may further include a polarizer, and the polarizer may be disposed at the reflector set, for example, the polarizer may be disposed at an incident end of the reflector set, or at an exit end of the reflector set, or inside the reflector set. The polarization direction of polaroid is the same with first polarizing film 11's polarization direction, and like this, the setting of polaroid will not cause the influence to the normal transmission of the light beam that carries the image signal, but can block in the external environment with the different light beam incidence of polarization direction of polaroid to image generation unit 10 in, thereby filter out the light beam (for example sunlight) that some external environment incided to image generation unit 10, and like this, through setting up the polaroid, the optical module that this application provided can also effectively reduce the sunshine and flow backward the phenomenon and cause the influence to image generation unit 10, and then avoid image generation unit 10 to take place to destroy or the quality is impaired because of overheated.

The polarizer may be reflective or absorptive, and may be selected by those skilled in the art according to the needs. However, in order to further improve the heat generation phenomenon of the optical element, in this embodiment, the polarizer is of a reflective type, so that the light beam that cannot be transmitted is reflected, thereby further reducing the heat generation phenomenon of the optical element.

In addition, in order to further improve the heat generation of the image generating unit 10 caused by the sunlight backflow phenomenon, optionally, referring to fig. 2, a transparent film 23 is disposed on the reflector set, and the transparent film 23 is used for transmitting the infrared light and/or the ultraviolet light incident to the reflector set from the front windshield 60; alternatively, the transmitting film 23 is used to transmit the ultraviolet light and part of the visible light incident on the mirror group from the front windshield 60. Since the infrared light and the ultraviolet light in the external environment have more energy, the transparent film 23 is provided to block the infrared light and/or the ultraviolet light from continuing to propagate, so that the heating influence of the external environment light on the image generating unit 10 can be effectively reduced.

In the present embodiment, the transparent film 23 is plated on the substrate of the mirror assembly, and the substrate of the mirror assembly on which the transparent film 23 is disposed is made of glass. That is, the material of the substrate for plating the permeation film 23 is glass. Like this, for materials such as adopting resin or ya keli as the basement, this application adopts the basement of glass material can realize establishing the direct plating of penetrating film 23, and the filming quality and the adhesion effect of rete are all better, and the technology is simpler, and can improve the yield.

Referring to fig. 3, optionally, the optical module further includes a dust-proof film 40, the dust-proof film 40 is located between the mirror group and the front windshield 60, and the dust-proof film 40 is used for transmitting the light beam emitted by the mirror group and guiding the light beam to the front windshield 60. The quality of the optical module provided by the application can be further improved by arranging the dustproof film 40.

Illustratively, as shown in fig. 4, the dust-proof film 40 includes a substrate 41 and a second polarizing film 42 attached to the substrate 41. When the polarization direction of the second polarizing film 42 is the same as the polarization direction of the first polarizing film 11, the external environment light incident into the optical module can be further screened through the second polarizing film 42, and then the external environment light is further filtered, so that the influence of the phenomenon of reverse flow of sunlight on the image generating unit 10 can be further improved.

Illustratively, as shown in fig. 3, the above-mentioned mirror group includes a first mirror 21 located at the light-emitting side of the image generating unit 10 and a second mirror 22 located at the light-emitting side of the first mirror 21, and the second mirror 22 is used for reflecting the light beam reflected by the first mirror 21 to the front windshield 60.

In the present embodiment, the reflecting surface of at least one of the first reflecting mirror 21 and the second reflecting mirror 22 is a free-form surface. Illustratively, the first mirror 21 and/or the second mirror 22 may be a double free-form surface mirror.

Optionally, the first reflector 21 or the second reflector 22 is plated with a transparent film 23, and the transparent film 23 is used for transmitting the infrared light and/or the ultraviolet light incident from the front windshield 60 to the reflector group; alternatively, the transmitting film 23 is used to transmit the ultraviolet light and part of the visible light incident on the mirror group from the front windshield 60; the substrate of the mirror provided with the transmission film 23 is made of glass. That is, if the first reflecting mirror 21 is provided with the transmissive film 23, the substrate of the first reflecting mirror 21 is made of glass; if the second reflecting mirror 22 is provided with the transparent film 23, the substrate of the second reflecting mirror 22 is made of glass; if the transmissive film 23 is provided on both the first reflecting mirror 21 and the second reflecting mirror 22, the substrates of both the first reflecting mirror 21 and the second reflecting mirror 22 are made of glass.

Optionally, the optical module further comprises a package housing for packaging the image generation unit 10 and the mirror group. Thus, the interference or influence of the external environment light on the light path and the imaging can be further reduced. The shape of the package housing can be adaptively designed according to the specific arrangement of each optical element of the optical module, and the application is not particularly limited.

In another aspect of the invention, a head-up display is provided, which includes the optical module. Since the detailed structure and the beneficial effects of the optical module have been described in detail in the foregoing, the detailed description is omitted here.

The above description is only an alternative embodiment of the present invention and is not intended to limit the present invention, and various modifications and variations of the present invention may occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

Claims

1. An optical module is characterized by comprising an image generation unit and a reflector set which are arranged in sequence; the image generation unit comprises a light source and a display unit positioned on the light emitting side of the light source, light beams emitted by the light source output image signals after passing through the display unit, and the image signals are reflected to the front windshield of the automobile through the reflector group and form images on the front windshield;

and a reflective first polarizing film is arranged between the light source and the display unit and used for reflecting part of light beams emitted by the light source.

2. The optical module of claim 1, wherein the display unit is any one of a TFT-LCD, DLP, LCOS.

3. The optical module according to claim 1, wherein when the display unit is a TFT-LCD or an LCOS, the transmission axis direction of the first polarizing film is identical to the transmission axis direction of the polarizer at the incident end of the display unit.

4. The optical module according to claim 1, wherein the reflector set is provided with a transparent film thereon, the transparent film being configured to transmit infrared light and/or ultraviolet light incident on the reflector set from the front windshield; or, the transmission film is used for transmitting ultraviolet light and part of visible light which are incident to the reflector group from the front windshield.

5. The optical module of claim 4, wherein the transparent film is plated on the substrate of the reflector set, and the substrate of the reflector set on which the transparent film is disposed is made of glass.

6. The optical module of claim 1 further comprising a dust mask positioned between the set of reflectors and the front windshield, the dust mask configured to transmit light beams exiting through the set of reflectors and to be directed toward the front windshield.

7. The optical module of claim 6, wherein the dust-proof film comprises a substrate and a second polarizing film attached to the substrate.

8. The optical module of any one of claims 1 to 7, wherein the mirror group comprises a first mirror on a light-emitting side of the image generation unit and a second mirror on a light-emitting side of the first mirror, the second mirror being configured to reflect the light beam reflected by the first mirror to the front windshield.

9. The optical module of claim 8 wherein the reflective surface of at least one of the first mirror and the second mirror is a free-form surface.

10. The optical module according to claim 8, wherein the substrate of the first reflector or the second reflector is coated with a transparent film for transmitting infrared light and/or ultraviolet light incident from the front windshield to the reflector group; or, the transmission film is used for transmitting ultraviolet light and part of visible light which are incident to the reflector group from the front windshield; and the substrate of the reflector provided with the transmission film is made of glass.

11. The optical module of any one of claims 1 to 7, further comprising an encapsulation housing for encapsulating the image generation unit and the set of mirrors.

12. A head-up display comprising an optical module according to any one of claims 1 to 11.