阅读说明：本技术 投影装置、镜头模块及其自动调焦方法 (Projection device, lens module and automatic focusing method thereof ) 是由 吴坤佑 于 2019-11-21 设计创作，主要内容包括：本发明提出一种镜头模块,包括一影像投射单元、一影像撷取单元以及一处理单元。影像投射单元设置于一影像光束的传递路径上,用于将影像光束投影至一投影目标上以形成一投影图样。影像撷取单元连接于影像投射单元,用于撷取投影图样以获得一成像信息。影像撷取单元的焦段对应影像投射单元的焦段。处理单元电连接于影像投射单元及影像撷取单元。处理单元接收来自影像撷取单元的成像信息并判断成像信息是否符合一预设值。处理单元依据一判断结果调整影像投射单元的焦距。本发明不需在投影装置的其他空间中配置撷取图像装置及不需投射出特定光学结构图案而实现影像投射单元的自动调焦。(The invention provides a lens module, which comprises an image projection unit, an image acquisition unit and a processing unit. The image projection unit is arranged on a transmission path of an image light beam and is used for projecting the image light beam onto a projection target to form a projection pattern. The image capturing unit is connected to the image projecting unit and used for capturing the projection pattern to obtain imaging information. The focal segment of the image capturing unit corresponds to the focal segment of the image projecting unit. The processing unit is electrically connected to the image projection unit and the image capture unit. The processing unit receives the imaging information from the image acquisition unit and judges whether the imaging information accords with a preset value. The processing unit adjusts the focal length of the image projection unit according to a judgment result. The invention realizes the automatic focusing of the image projection unit without arranging an image capturing device in other spaces of the projection device and projecting a specific optical structure pattern.)

1. A lens module, comprising: the image projection unit, the image acquisition unit and the processing unit; wherein the content of the first and second substances,

the image projection unit is arranged on a transmission path of the image light beam and is used for projecting the image light beam onto a projection target to form a projection pattern;

the image capturing unit is connected to the image projecting unit and used for capturing the projection pattern to obtain imaging information, and a focal section of the image capturing unit corresponds to a focal section of the image projecting unit; and

the processing unit is electrically connected to the image projection unit and the image capturing unit, receives the imaging information from the image capturing unit and judges whether the imaging information meets a preset value, and the processing unit adjusts the focal length of the image projection unit according to a judgment result.

2. The lens module as claimed in claim 1, wherein the image projection unit includes a projection lens and an adjustment mechanism, and the processing unit controls the adjustment mechanism to adjust the projection lens according to the imaging information.

3. The lens module as claimed in claim 1, wherein an optical axis of the image projection unit is parallel to an optical axis of the image capture unit.

4. The lens module as claimed in claim 1, wherein the image projection unit includes a beam splitter for passing the image beam and reflecting the projection pattern reflected by the projection target to the image capture unit.

5. The lens module as claimed in claim 4, wherein the image projection unit and the image capture unit share the same optical system.

6. The lens module as claimed in claim 1, wherein the image capturing unit captures the projection pattern projected by the image projecting unit after adjustment and obtains another imaging information, and the processing unit determines whether the another imaging information matches a predetermined value.

7. A projection device, comprising: the lighting system, at least one light valve and the lens module; wherein the content of the first and second substances,

the illumination system is used for providing an illumination light beam;

the at least one light valve is arranged on the transmission path of the illumination light beam and is used for converting the illumination light beam into an image light beam; and

the lens module includes: the image projection unit, the image acquisition unit and the processing unit; wherein the content of the first and second substances,

the image projection unit is arranged on a transmission path of the image light beam and is used for projecting the image light beam onto a projection target to form a projection pattern;

the image capturing unit is connected to the image projecting unit and used for capturing the projection pattern to obtain imaging information, and a focal section of the image capturing unit corresponds to a focal section of the image projecting unit; and

the processing unit is electrically connected to the image projection unit and the image capturing unit, receives the imaging information from the image capturing unit and judges whether the imaging information meets a preset value, and the processing unit adjusts the focal length of the image projection unit according to a judgment result.

8. The projection apparatus as claimed in claim 7, wherein the image projection unit includes a projection lens and an adjustment mechanism, and the processing unit controls the adjustment mechanism to adjust the projection lens according to the imaging information.

9. The projection apparatus according to claim 7, wherein an optical axis of the image projection unit is parallel to an optical axis of the image capture unit.

10. The projection apparatus as claimed in claim 7, wherein the image projection unit includes a beam splitter for passing the image beam from the at least one light valve and reflecting the projection pattern reflected by the projection target to the image capture unit.

11. The projection apparatus according to claim 10, wherein the image projection unit and the image capture unit share a same optical system.

12. The projection apparatus as claimed in claim 7, wherein the image capturing unit captures the projection pattern projected by the image projecting unit after adjustment and obtains another image information, and the processing unit determines whether the another image information matches a predetermined value.

13. An automatic focusing method of a lens module, wherein the lens module includes an image projection unit, an image capture unit connected to the image projection unit, and a processing unit, and a focal segment of the image capture unit corresponds to a focal segment of the image projection unit, the automatic focusing method comprising:

focusing towards a projection target by the image capturing unit;

projecting the image beam onto a projection target by the image projection unit to form a projection pattern;

capturing the projection pattern by the image capturing unit to obtain imaging information;

receiving, by the processing unit, the imaging information from the image capture unit; and

and judging whether the imaging information accords with a preset value or not by the processing unit and adjusting the focal length of the image projection unit according to a judgment result.

14. The auto-focusing method of claim 13, further comprising capturing the projection pattern projected by the adjusted image projection unit by the image capture unit and obtaining another image information, wherein the processing unit determines whether the another image information satisfies a predetermined value.

15. The autofocus method according to claim 14, wherein when the determination result is that the imaging information matches the preset value, autofocus is stopped.

16. The autofocus method of claim 13, further comprising:

and storing the adjusted focal length information of the image projection unit.

Technical Field

The present invention relates to an optical device, an optical module and a method for using the same, and more particularly, to a projection device, a lens module and an automatic focusing method thereof.

Background

A projector is a display device for generating large-size images, and is continuously advanced along with the evolution and innovation of industrial technology. The imaging principle of the projector is to convert the illumination beam generated by the illumination system into an image beam by a light valve, and then project the image beam to a projection target (e.g., a screen or a wall surface) through a projection lens to form a projection image.

In order to achieve the purpose of automatic focusing, one or two camera lenses are arranged on the front cover of the shell of the projector and used for detecting the fuzzy degree of a projection picture so as to adjust the focal length, thereby achieving the purpose of automatic focusing of the projection lens. However, the above-mentioned method will make the application of the engineering projector have different projection distances due to the installation space limitation, and in order to cope with such various use scenarios, the engineering projector has a plurality of projection lenses, and each projection lens has a different focal length to satisfy the application situation. In addition, for the purpose of auto-focusing, the built-in camera lens must cover the projection distance of the projection lens to obtain the best image capturing effect. In other words, the camera lens limits the auto-focusable range of the projection lens.

The background section is only provided to aid in understanding the present disclosure, and thus the disclosure in the background section may include some prior art that does not constitute a part of the knowledge of one skilled in the art. The disclosure in the "background" section does not represent a representation of the disclosure or the problems that may be solved by one or more embodiments of the present invention, but is known or appreciated by those skilled in the art prior to the filing of the present application.

Disclosure of Invention

The invention provides a projection device, a lens module and an automatic focusing method thereof, which can realize automatic focusing of an image projection unit without arranging an image capturing device in other spaces of the projection device and projecting a specific optical structure pattern.

Other objects and advantages of the present invention will be further understood from the technical features disclosed in the present invention.

In order to achieve one or a part of or all of the above objectives or other objectives, an embodiment of the invention provides a lens module, which includes an image projection unit, an image capture unit, and a processing unit. The image projection unit is arranged on a transmission path of an image light beam and is used for projecting the image light beam onto a projection target to form a projection pattern. The image capturing unit is connected to the image projecting unit and used for capturing the projection pattern to obtain imaging information. The focal segment of the image capturing unit corresponds to the focal segment of the image projecting unit. The processing unit is electrically connected to the image projection unit and the image capture unit. The processing unit receives the imaging information from the image acquisition unit and judges whether the imaging information accords with a preset value. The processing unit adjusts the focal length of the image projection unit according to a judgment result.

In order to achieve one or a part of or all of the above objectives or other objectives, another embodiment of the invention provides a projection apparatus including an illumination system, at least one light valve, and a lens module. The illumination system is used for providing an illumination light beam. The at least one light valve is arranged on the transmission path of the illumination light beam and used for converting the illumination light beam into an image light beam. The lens module comprises an image projection unit, an image acquisition unit and a processing unit. The image projection unit is arranged on a transmission path of an image light beam and is used for projecting the image light beam onto a projection target to form a projection pattern. The image capturing unit is connected to the image projecting unit and used for capturing the projection pattern to obtain imaging information. The focal segment of the image capturing unit corresponds to the focal segment of the image projecting unit. The processing unit is electrically connected to the image projection unit and the image capture unit. The processing unit receives the imaging information from the image acquisition unit and judges whether the imaging information accords with a preset value. The processing unit adjusts the focal length of the image projection unit according to a judgment result.

In order to achieve one or a part of or all of the above objectives or other objectives, another embodiment of the present invention provides an auto-focusing method for a lens module, wherein the lens module includes an image projection unit, an image capturing unit connected to the image projection unit, and a processing unit, and a focal length of the image capturing unit corresponds to a focal length of the image projection unit, the auto-focusing method comprising: focusing towards a projection target by the image acquisition unit; projecting an image beam onto a projection target by the image projection unit to form a projection pattern; capturing the projection pattern by the image capturing unit to obtain imaging information; receiving imaging information from the image acquisition unit by the processing unit; and judging whether the imaging information accords with a preset value or not by the processing unit and adjusting the focal length of the image projection unit according to a judgment result.

Based on the above, the embodiments of the invention have at least one of the following advantages or efficacies. In the projection apparatus, the lens module and the automatic focusing method thereof of the present invention, the image capturing unit is connected to the image projecting unit, and the image capturing unit captures the projection pattern to obtain the imaging information, thereby determining whether the imaging information conforms to the preset value. The processing unit adjusts the focal length of the image projection unit according to the judgment result. Therefore, the image projection unit can realize automatic focusing and meet the requirements of the lens module without additional configuration or replacement of the image projection unit with different focal length capabilities. In addition, a camera, a video camera or other image capturing devices are not required to be additionally arranged in other spaces of the projection device, so that the installation space of the projection device can be saved, and the projection device can be simultaneously suitable for different scenes when the projection pattern is positioned at different distances. In addition, in the automatic focusing process of the embodiment, a specific optical structure pattern does not need to be projected.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 is a schematic view of a projection apparatus according to an embodiment of the invention.

Fig. 2 is another schematic view of the projection apparatus of fig. 1.

Fig. 3 is a schematic view of a portion of the projection apparatus of fig. 1.

Fig. 4 is a schematic view of a portion of a projection apparatus according to another embodiment of the invention.

Fig. 5 is a flowchart illustrating an auto-focusing method of a lens module according to an embodiment of the invention.

List of reference numerals

10. 10A: projection device

50: lighting system

60: light valve

100. 100A: lens module

110. 110A: image projection unit

112: projection lens

114: adjusting mechanism

116: light splitting element

120: image acquisition unit

130: processing unit

LB: illuminating light beam

And LI: image light beam

P: projection pattern

S200 to S204: and (5) carrying out the following steps.

Detailed Description

The foregoing and other technical and scientific aspects, features and utilities of the present invention will be apparent from the following detailed description of a preferred embodiment when read in conjunction with the accompanying drawings. Directional terms as referred to in the following examples, for example: up, down, left, right, front or rear, etc., are simply directions with reference to the drawings. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting.

Fig. 1 is a schematic view of a projection apparatus according to an embodiment of the invention. Please refer to fig. 1. In the present embodiment, the projection apparatus 10 is used for providing the image light beam LI. Specifically, the projection apparatus 10 includes an illumination system 50, at least one light valve 60, and a lens module 100, and the illumination system 50 is used for providing an illumination beam LB. The light valve 60 is disposed on a transmission path of the illumination beam LB and is configured to convert the illumination beam LB into at least one image beam LI. By illumination beam LB is meant the beam that illumination system 50 provides to light valve 60 at any time. The lens module 100 is disposed on a transmission path of the image light beam LI, and is configured to receive the image light beam LI from the light valve 60 and project the image light beam LI to a projection target (not shown), such as a screen or a wall surface.

The illumination system 50 is composed of a plurality of light emitting elements, a light wavelength conversion element, a light uniformizing element, a filter element, and a plurality of light splitting and combining elements, for example, and is configured to provide light with different wavelengths as a source of image light. However, the present invention is not limited to the type or form of the illumination system 50 in the projection apparatus 10, and the detailed structure and implementation thereof can be taught, suggested and implemented sufficiently by the general knowledge in the art, and thus will not be described in detail herein.

The light valve 60 is a reflective light modulator such as a Liquid Crystal On Silicon (LCoS) panel, a Digital Micromirror Device (DMD), or the like. In some embodiments, the light valve 60 may also be a transmissive light Modulator such as a transmissive Liquid Crystal Panel (transmissive Liquid Crystal Panel), an Electro-Optic Modulator (Electro-Optic Modulator), a magneto-Optic Modulator (magneto-Optic Modulator), an Acousto-Optic Modulator (AOM), or the like. The type and type of the light valve 60 are not limited in the present invention. The detailed steps and embodiments of the method for converting the illumination beam LB into the image beam LI by the light valve 60 can be obtained by the general knowledge in the art, and therefore, the detailed description thereof is omitted here. In the present embodiment, the number of the light valves 60 is one, such as the projection apparatus 10 using a single digital micromirror device (1-DMD), but in other embodiments, the number may be multiple, and the invention is not limited thereto.

Fig. 2 is another schematic view of the projection apparatus of fig. 1. Fig. 3 is a schematic view of a portion of the projection apparatus of fig. 1. Please refer to fig. 2 and fig. 3. In the present embodiment, the lens module 100 includes an image projecting unit 110, an image capturing unit 120, and a processing unit 130. The image projection unit 110 is disposed on a transmission path of the image light beam LI, and is configured to receive the image light beam LI from the light valve 60 and project the image light beam LI onto a projection target to form a projection pattern P.

The image projection unit 110 includes a projection lens 112 and an adjusting mechanism 114, wherein the adjusting mechanism 114 is connected to the projection lens 112 for adjusting the focal length of the projection lens 112. In detail, the projection lens 112 is, for example, a combination of one or more optical lenses having diopter, and includes various combinations of non-planar lenses such as a biconcave lens, a biconvex lens, a meniscus lens, a convex-concave lens, a plano-convex lens, and a plano-concave lens. In one embodiment, the projection lens 112 may also include a planar optical lens for projecting the image light LI from the light valve 60 to a projection target in a reflective or transmissive manner. The present invention is not limited to the type and kind of the projection lens 112.

The image capturing unit 120 is connected to the image projecting unit 110, and is configured to capture the projection pattern P toward a projection target (not numbered) to obtain imaging information. Specifically, the imaging information is, for example, Image Sharpness (Image Sharpness) obtained when the projection pattern P is captured, wherein the Image Sharpness varies with the focal length of the Image capturing unit 120. The higher the image sharpness, the closer the falling point of the focal segment of the image capturing unit 120 is to the location of the projection pattern P. The image capturing unit 120 is, for example, a combination of a photosensitive device and one or more optical lenses with diopter, as shown in fig. 3, wherein the photosensitive device is, for example, a device for converting an optical image into a digital signal. In the present embodiment, the optical axis of the image projection unit 110 is parallel to the optical axis of the image capture unit 120. Therefore, the image projection unit 110 and the image capture unit 120 are connected side by side, and in appearance, the same opening of the housing (not numbered) projects and captures images from the exterior of the projection apparatus 10, as shown in fig. 2. It should be noted that, in the present embodiment, the focal segment of the image capturing unit 120 corresponds to the focal segment of the image projecting unit 110. Specifically, the focal length of the image capturing unit 120 may vary according to the focal length of the image projecting unit 110.

The processing unit 130 is electrically connected to the image projecting unit 110 and the image capturing unit 120, respectively, for receiving the imaging information obtained by the image capturing unit 120 when capturing the projected pattern P, and determining whether the imaging information meets a predetermined value, and the processing unit 130 adjusts the focal length of the image projecting unit 110 according to the determination result. For example, in the present embodiment, the imaging information is the sharpness of the image obtained when the projection pattern P is captured, and the preset value is a preset range of sharpness values stored in other storage units in the projection apparatus 10 or in the processing unit 130.

In detail, after the image capturing unit 120 captures the projection pattern P toward the projection target and obtains the image sharpness (imaging information), the processing unit 130 compares the image sharpness with a preset image sharpness value setting range, and adjusts the focal length of the image projecting unit 110 if the image sharpness is outside the preset image sharpness value setting range. In other words, in the present embodiment, the processing unit 130 controls the adjusting mechanism 114 in the image projection unit 110 to adjust the projection lens 112 according to the imaging information. In this way, the image projection unit 110 can achieve automatic focusing and meet the requirements of the lens module 100 without additional configuration or replacement of the image projection unit 110 with different focal length capabilities. In addition, it is not necessary to additionally arrange a camera, a video camera or other image capturing devices in other spaces of the projection apparatus 10, so as to save the installation space of the projection apparatus 10 and adapt to different situations when the projection pattern P is located at different projection distances. In addition, in the automatic focusing process of the embodiment, a specific optical structure pattern does not need to be projected.

Furthermore, in the present embodiment, after the automatic focusing of the image projection unit 110 is completed, the image capturing unit 120 captures the projection pattern projected by the adjusted image projection unit 110 and obtains another piece of imaging information, and the processing unit 130 determines whether the another piece of imaging information meets a predetermined value. And when the judgment result of the other imaging information is that the imaging information accords with the preset value, stopping automatic focusing. In other words, in the present embodiment, besides performing the auto-focusing once, the processing unit 130 can be driven to adjust the image projecting unit 110 according to different imaging information by using the imaging information obtained by the image capturing unit 120 until the adjustment is not needed. Accordingly, the lens module 100 may repeatedly implement auto-focusing.

Fig. 4 is a schematic view of a portion of a projection apparatus according to another embodiment of the invention. Please refer to fig. 4. The projection apparatus 10A of the present embodiment is similar to the projection apparatus 10 shown in fig. 3. The difference between the two embodiments is that, in the embodiment, the lens module 100A of the projection apparatus 10A includes an image projection unit 110A and an image capture unit 120, and the image projection unit 110A includes a light splitting element 116 for allowing the image light beam LI transmitted in the image projection unit 110A to pass through and reflecting the projection pattern P reflected by the projection target to the image capture unit 120. That is, the image capturing unit 120 receives the light beam reflected from the light splitting element 116 in the image projecting unit 110A. Therefore, in the present embodiment, the image projection unit 110A and the image capture unit 120 may share the same optical system, as shown in fig. 4, wherein the transmission direction of the image light beam LI from the light valve 60 in the projection lens 112 is opposite to the transmission direction of the projection pattern P reflected by the projection target entering at least a portion of the projection lens 112. Therefore, the space occupied by the optical system of the image capturing unit 120 can be saved, and the volume of the projection apparatus 10A can be reduced and the manufacturing cost can be reduced.

Fig. 5 is a flowchart illustrating an auto-focusing method of a lens module according to an embodiment of the invention. Please refer to fig. 5. In the present embodiment, the auto-focusing method of the lens module can be applied to at least the lens modules 100 and 100A shown in fig. 1 to 4, and the lens module 100 shown in fig. 2 and 3 will be taken as an example. First, step S200 is executed to focus on the projection target by the image capturing unit 120. Next, after the above steps, step S201 is executed to project the image light beam LI onto the projection target by the image projection unit 110 to form a projection pattern P. The focal length of the image capturing unit 120 corresponds to the focal length of the image projecting unit 110. Next, after the above steps, step S202 is executed to acquire the projection pattern P by the image acquisition unit 120 to obtain imaging information. Next, after the above steps, step S203 is executed, in which the processing unit 130 receives the imaging information from the image capturing unit 120. Next, after the above steps, step S204 is executed, in which the processing unit 130 determines whether the imaging information meets the predetermined value and adjusts the focal length of the image projecting unit 110 according to the determination result. In this way, the image projection unit 110 can achieve automatic focusing and meet the requirements of the lens module 100 without additional configuration or replacement of the image projection unit 120 with different focal length capabilities. In addition, it is not necessary to additionally arrange a camera, a video camera or other image capturing devices in other spaces of the projection apparatus 10, so as to save the installation space of the projection apparatus 10 and adapt to different situations when the projection pattern P is located at different distances. In addition, in the automatic focusing process of the embodiment, a specific optical structure pattern does not need to be projected.

In summary, the embodiments of the invention have at least one of the following advantages or effects. In the projection apparatus, the lens module and the automatic focusing method thereof of the present invention, the image capturing unit is connected to the image projecting unit, and the image capturing unit captures the projection pattern to obtain the imaging information, thereby determining whether the imaging information conforms to the preset value. The processing unit adjusts the focal length of the image projection unit according to the judgment result. Therefore, the image projection unit can realize automatic focusing and meet the requirements of the lens module without additional configuration or replacement of the image projection unit with different focal length capabilities. In addition, a camera, a video camera or other image capturing devices are not required to be additionally arranged in other spaces of the projection device, so that the installation space of the projection device can be saved, and the projection device can be simultaneously suitable for different scenes when the projection pattern is positioned at different distances. In addition, in the automatic focusing process of the embodiment, a specific optical structure pattern does not need to be projected.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the scope of the invention, which is defined by the appended claims and their equivalents. It is not necessary for any embodiment or claim of the invention to achieve all of the objects or advantages or features disclosed herein. Furthermore, the abstract and the title of the specification are provided only for assisting the retrieval of patent documents and are not intended to limit the scope of the present invention. Furthermore, the terms "first", "second", and the like in the description or the claims are used only for naming elements (elements) or distinguishing different embodiments or ranges, and are not used for limiting the upper limit or the lower limit on the number of elements.