Patent Publication Number: US-11384917-B1

Title: Headlight and projection device for vehicles

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 110107214, filed on Mar. 2, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND 
     Technical Field 
     This disclosure relates to an optical device, and in particular to a headlight and a projection device for vehicles. 
     Description of Related Art 
     With advancements in science and technology, the invention of vehicles such as automobiles has rapidly shortened the distance between humans. Although the automobile technology has brought convenience to the lives of people, at the same time, the number of casualties due to traffic accidents remains high due to the lack of wholesome driving education and training, and cultivation of good driving habits. Therefore, developed countries and major car manufacturers are actively seeking for a way to apply technology to vehicles to improve the safety of the vehicles and reduce the incidence of traffic accidents. Therefore, how to improve driving safety remains the primary goal in this field. 
     However, in the current technology, the projection lens module of the car lamp does not have the function of adjusting its aperture, and a balance has to be found between the brightness, resolution, and contrast. Therefore, an additional indicator light assembly has to be configured whenever an additional indicative light is provided. 
     SUMMARY 
     This disclosure provides a headlight for vehicles, which can provide a high-brightness illumination light, and high-resolution and high-contrast indicative patterns. 
     The disclosure provides a headlight for vehicles, which includes an image light source, a lens assembly, an aperture, a lens cover, and a driving device. A lens module includes the lens assembly and the aperture. The lens assembly is disposed at downstream of an optical path of the image light source. The aperture includes a base and a movable mechanical member. The aperture is disposed at the downstream of the optical path of the image light source. The lens cover is disposed at downstream of an optical path of the aperture. The driving device is connected to the aperture. The driving device includes a power source and a linkage member connected to the movable mechanical member. The lens module includes at least two aperture values, and the aperture values are both not greater than 2.0. 
     The disclosure also provides a projection device for vehicles, which includes a matrix image light source, a lens module, and a driving device. The lens module includes two diopter lenses and an aperture. The lens module is disposed at downstream of an optical path of the image light source. The aperture includes a movable mechanical member. The driving device is ly connected to the aperture. The driving device includes a driving mechanism and a linkage mechanical member connected to the movable mechanical member. The driving mechanism may drive the linkage mechanical member and drive the movable mechanical member to change an aperture value of the projection device, and the aperture value of the projection device is less than or equal to 2.0. 
     Based on the above, in the headlight and the projection device of the disclosure, the aperture includes the movable mechanical member, and the driving device includes the power source and the linkage member connected to the movable mechanical member. Therefore, beams of different patterns may be provided by the image light source, and the aperture may be adjusted by the driving device, so as to adjust the aperture value. This enables the high-brightness illumination light or the high-resolution and high-contrast indicative patterns to be provided in the different situations. In this way, the driving safety can be improved, and allows the driver to enjoy good quality during driving. 
     To make the abovementioned more comprehensible, several embodiments accompanied by drawings are described in detail as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a headlight according to an embodiment of the disclosure. 
         FIG. 2  is another schematic diagram of the headlight according to the embodiment in  FIG. 1  on an optical axis. 
         FIG. 3  shows detailed optical data of the headlight according to the embodiment in  FIG. 2 . 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
       FIG. 1  is a schematic diagram of a headlight according to an embodiment of the disclosure.  FIG. 2  is another schematic diagram of the headlight according to the embodiment in  FIG. 1  on an optical axis. With reference to  FIGS. 1 and 2  concurrently, the embodiment provides a headlight  100  for vehicles, which has a function of automatically adjusting an aperture value, and may provide a high-brightness illumination light, and high-resolution and high-contrast indicative patterns. That is, a projection device for vehicles. In the embodiment, the headlight  100  includes an image light source  110 , a lens module  200  (including a lens assembly  120  and an aperture  130 ), a lens cover  140 , and a driving device  150 . The image light source  110  in the headlight  100  is configured to provide an image beam B, and the lens assembly  120  and the lens cover  140  are configured on a transmission path of the image beam B. The lens module  200  includes at least two diopter lenses, which are configured to project the image beam B out of the headlight  100  to a projection target (not shown), such as a road or a wall. The headlight  100  of the embodiment may be widely used in railway vehicles, cars, bicycles, motorcycles, airplanes, and other vehicles. 
     In detail, in the embodiment, the image light source  110  is, for example, a micro light-emitting diode array (micro LED array) or a digital micromirror device (DMD), which is usually a matrix type image light source, but the disclosure is not limited thereto. The image beam B provided by the image light source  110  may vary at different timings, such as in an illumination state or an indicative state. The shape of a projection spot of the image beam B in the illumination state is different from the shape of a projection spot of the image beam in the indicative state. Specifically, the image beam B in the illumination state is, for example, a light beam with a higher light intensity and no specific pattern, which is configured to be used as an illumination light with sufficient brightness and in compliance with regulations during driving. The image beam B in the indicative state is, for example, a beam with a specific pattern, for example, a geometric pattern such as an arrow, a square, a triangle, and a circle, which is configured to serve as a pattern or a signal having reminding applications during driving. 
       FIG. 3  shows detailed optical data of the headlight according to the embodiment in  FIG. 2 . With reference to  FIGS. 2 and 3  concurrently, the lens assembly  120  is disposed at downstream of an optical path of the image light source  110 . That is, it is configured on a transmission path of the image beam B, and is configured to enlarge and project the image beam B to the projection target. The lens assembly  120  may be a combination of multiple optical lenses with diopters that are all non-zero, but the disclosure is not limited thereto. In the embodiment, a material of at least a part of the lens is plastic, and a material of at least another part of the lens is glass, but the disclosure is not limited thereto. 
     For example, in the embodiment, the lens assembly  120  is composed of two lenses. The lens assembly  120  includes a first lens  122  and a second lens  124 . The material of the first lens  122  is plastic, and a surface S 1  of the first lens  122  facing a magnification side A 1  is convex, and a surface S 2  facing a reduction side A 2  is concave. The material of the second lens  124  is glass, and a surface S 4  of the second lens  124  facing the magnification side A 1  is convex, and a surface S 5  facing the reduction side A 2  is concave. In addition, in the embodiment, surfaces S 1 , S 2 , S 3 , S 4 , S 5 , and S 6  of the first lens  122 , an aperture  130 , the second lens  124 , and the image light source  110  may all be aspherical, but the disclosure is not limited thereto. Other detailed optical data of the embodiment is shown in  FIG. 3 . 
     With reference to  FIGS. 1 to 3  again, the aperture  130  is disposed at downstream of the optical path of the image light source  110 . That is, it is configured on the transmission path of the image beam B, and is configured to control an aperture value of the headlight. 
     In the embodiment, the aperture  130  is configured between two adjacent lenses, that is, between the first lens  122  and the second lens  124 . However, in other embodiments, the aperture  130  may also be configured on a side of the first lens  122  facing the magnification side A 1 , or may be configured on a side of the second lens  124  facing the reduction side A 2 , but the disclosure is not limited thereto. The aperture  130  has an aperture value, and the aperture  130  changes the aperture value according to the state of the image beam B. In detail, the aperture  130  includes a base  132  and a movable mechanical member  134 . Specifically, the base  132  is, for example, a metal hollow frame, and the movable mechanical member  134  is, for example, a deformable mechanism configured in the base  132 , and is configured to change a hole diameter to adjust the aperture value. In the embodiment, the lens module  200  has at least two aperture values, and the at least two aperture values are both not greater than 2.0. That is, the movable mechanical member  134  of the aperture  130  may switch to at the hole diameter with the at least two different aperture values. A projection aspect ratio of the projection device is preferably between 2.5:1 and 6:1. 
     The lens cover  140  is disposed at downstream of an optical path of the aperture  130 . That is, it is configured on the transmission path of the image beam B, and the aperture  130  is located between the image light source  110  and the lens cover  140 . The lens cover  140  covers optical elements such as the lens assembly  120  and the aperture  130 . 
     The driving device  150  is connected to the aperture  130 , and the driving device  150  includes a power source  152  and a linkage member  154  connected to the movable mechanical member  134  of the aperture  130 . That is, the power source  152  of the driving device  150  is connected to the movable mechanical member  134  of the aperture  130  through the linkage member  154  directly or indirectly. Specifically, the power source  152  is, for example, an electromagnet, or a motor, in a form of a driving mechanism such as a voice coil motor or a stepping motor. The linkage member  154  is, for example, a connecting rod or a gear. The power source  152  is configured to provide power to drive the linkage member  154 , and then drives the movable mechanical member  134  of the aperture  130  by the linkage member  154 . Therefore, the aperture  130  may be driven by the driving device  150  to adjust the aperture value of the headlight  100 , and then allows the image light source  110  to provide the high-brightness illumination light or the high-resolution and high-contrast indicative patterns in different situations. In this way, driving safety can be improved, and enables a driver to enjoy good quality during driving. 
     In the embodiment, the headlight  100  further includes a sensing unit  160  and a calculation unit  170 . The sensing unit  160  is electrically connected to the calculation unit  170 , and the calculation unit  170  is electrically connected to the driving device  150 . The sensing unit  160  is configured to receive an external signal D 1 , so as to generate an electronic signal D 2 , and the calculation unit  170  is configured to receive the electronic signal D 2 , so as to generate a control signal D 3  to the driving device  150 . The sensing unit  160  is, for example, a photosensitive element such as a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) transistor. The calculation unit  170  is, for example, a central processing unit (CPU) or an engine control unit (ECU). The projection aspect ratio of the projection device is between 2.5:1 and 6:1. However, the disclosure is not limited thereto. 
     Therefore, the calculation unit  170  controls the driving device  150 , so to adjust the hole diameter of the aperture  130  to become larger when the image beam B provided by the image light source  110  is in the illumination state. This enables the image beam B in the illumination state to pass through the aperture  130  with a large hole diameter, so as to provide sufficient brightness. On the other hand, the calculation unit  170  controls the driving device  150  to adjust the hole diameter of the aperture  130  to become smaller when the image beam B provided by the image light source  110  is in the indicative state. This enables the image beam B in the indicative state to pass through the aperture  130  with a small hole diameter, so as to increase the resolution of illumination patterns. 
     For example, in the embodiment, the calculation unit  170  controls the driving device  150  according to the image light source  110 , so as to adjust the aperture value of the aperture  130  to f/0.7, thereby achieving an efficiency of 38.9% when the image beam B provided by the image light source  110  is in the illumination state. On the other hand, the calculation unit  170  controls the driving device  150  according to the image light source  110 , so as to adjust the aperture value of the aperture  130  (that is, the movable mechanical member  134  that drives the aperture  130 ) to f/1.5 when the image beam B provided by the image light source  110  is in the indicative state, thereby obtaining high-resolution optical patterns, and then indicating traffic information to be provided to other drivers. In other words, in the embodiment, the aperture value corresponding to the image beam B in the illumination state is less than the aperture value corresponding to the image beam B in the indicative state. 
     Therefore, the headlight  100  of the embodiment may provide light beams of different patterns through the image light source  110 , and adjust the hole diameter of the aperture  130  through the driving device  150 , so as to adjust the aperture value. This enables the high-brightness illumination light or the high-resolution and high-contrast indicative patterns to be provided in the different situations. In this way, the driving safety can be improved, and enables the driver to enjoy good quality during driving. 
     In summary, in the headlight and the projection device according to the disclosure, the aperture includes the movable mechanical member, and the driving device includes the power source and the linkage member connected to the movable mechanical member. Therefore, the beams of different patterns may be provided by the image light source, and the hole diameter of the aperture may be adjusted by the driving device, so as to adjust the aperture value. This enables the high-brightness illumination light or the high-resolution and high-contrast indicative patterns to be provided in the different situations. In this way, the driving safety can be improved, and enables the driver to enjoy good quality during driving. 
     Although the disclosure has been described with reference to the abovementioned embodiments, but it is not intended to limit the disclosure. It is apparent that any one of ordinary skill in the art may make changes and modifications to the described embodiments without departing from the spirit and the scope of the disclosure. Accordingly, the scope of the disclosure is defined by the claims appended hereto and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated.