Focus adjusting assembly, optical engine and projection device

Abstract

The present disclosure provides a focusing assembly, an optical engine and a projection device. The focusing assembly comprises: a lens barrel, which is externally provided with a convex point; a focusing ring, which is mounted on the lens barrel, and the inside of the focusing ring is provided with a sliding rail matched with the convex point, and the sliding rail is arc-shaped; the outside of the focusing ring is provided with a gear structure; a pinion, which is engaged with the gear structure; and a motor, which is locked with the pinion, and is used to control the rotation of the focusing ring through the pinion. The focusing assembly, the optical engine and the projection device can achieve the effect of uniform linear focusing during the focusing process, ensure that the projection picture can be well focused in the small size change interval and the large size change interval, and make the projection picture stop at the clear point, thereby improving the focusing effect.

Description

Technical Field

[0001] This disclosure relates to the field of projection technology, and in particular to a focusing component, an optical engine, and a projection device. Background Technology

[0002] With the development of high resolution and high transmittance in liquid crystal displays (LCDs), LCD projector engines are becoming increasingly popular. However, as panel resolution and lens resolution continue to improve, higher demands are being placed on the focusing capabilities of LCD projector engines.

[0003] Currently, the lenses of LCD projectors on the market are all non-linear focusing designs. This makes it easy for the lens to stop at the sharpest point when autofocusing on small-sized images, but difficult for the lens to stop at the sharpest point when autofocusing on large-sized images. Summary of the Invention

[0004] In view of this, the purpose of this disclosure is to provide a focusing assembly, an optical engine, and a projection device.

[0005] For the purposes described above, the first aspect of this disclosure provides a focusing assembly, comprising:

[0006] The lens barrel has raised dots on the outside;

[0007] A focusing ring is mounted on the lens barrel. The focusing ring has an internal slide rail that mates with the protrusion. The slide rail is arc-shaped. The focusing ring also has a gear structure on its exterior.

[0008] The pinion meshes with the gear structure;

[0009] A motor, locked to the pinion gear, is used to control the rotation of the focusing ring via the pinion gear.

[0010] In some embodiments, the arc shape of the slide rail is obtained based on the inverse function of the focusing curve.

[0011] In some embodiments, the focusing curve includes: the distance between the front lens and the lens as a function of the projected image size.

[0012] In some embodiments, the focusing curve is determined based on the focal length, the distance between the front lens and the lens, and the projection ratio, which is obtained based on the projection image distance and the projection screen width.

[0013] In some embodiments, the slide rail includes a first slide rail region and a second slide rail region, the first slide rail region corresponds to the variation range of the first projection size, the second slide rail region corresponds to the variation range of the second projection size, and the variation range of the second projection size is greater than the variation range of the first projection size.

[0014] The slope of the first slide rail region is greater than the reference slope parameter, and the slope of the second slide rail region is less than the reference slope parameter. The reference slope parameter is the slope of the straight line structure formed by connecting the two ends of the slide rail.

[0015] In some embodiments, the first projection size varies from 40 to 80 inches, and the second projection size varies from 80 to 120 inches.

[0016] In some embodiments, the slope of the first slide rail region and / or the slope of the second slide rail region are determined based on the distance between the front lens and the lens and the radian range of the focusing ring rotation.

[0017] In some embodiments, the slope k of the slide rail satisfies k→(1 / 2,+∞).

[0018] A second aspect of this disclosure provides an optical engine, comprising:

[0019] The host includes a main housing and an image projection unit disposed on the main housing; and,

[0020] The focusing assembly as described in the first aspect is disposed on the main housing.

[0021] A third aspect of this disclosure provides a projection device, comprising:

[0022] As described in the second aspect, the optical mechanism; and,

[0023] A projection screen is used to receive the projected image from the optical engine.

[0024] As can be seen from the above, the focusing component, optical engine, and projection device provided in this disclosure, by setting the slide rail inside the focusing ring to an arc shape, reduce the ratio of the projected image size to the forward and backward movement of the lens during the focusing process, especially when the projected image is in a small to medium size variation range; and increase the ratio when the projected image is in a medium to large size variation range. This achieves a uniform linear focusing effect during the focusing process, ensuring that the projected image can be well focused and brought to a clear point regardless of whether the projected image is in a small or large size variation range, thus improving the focusing effect. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in this disclosure or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of an exemplary optical engine provided in an embodiment of this disclosure is shown.

[0027] Figure 2 A schematic diagram of an exemplary flange provided in an embodiment of this disclosure is shown.

[0028] Figure 3 A schematic diagram of an exemplary lens barrel provided in an embodiment of this disclosure is shown.

[0029] Figure 4 A schematic diagram of an exemplary lens barrel provided in an embodiment of this disclosure is shown.

[0030] Figure 5 A schematic diagram of an exemplary lens barrel provided in an embodiment of this disclosure is shown.

[0031] Figure 6 A schematic diagram of an exemplary focusing ring provided in an embodiment of this disclosure is shown.

[0032] Figure 7 A schematic diagram of an exemplary focusing ring provided in an embodiment of this disclosure is shown.

[0033] Figure 8 A schematic diagram of an exemplary focusing ring is shown.

[0034] Figure 9 A schematic diagram of an exemplary pinion provided in an embodiment of this disclosure is shown.

[0035] Figure 10 A schematic diagram of an exemplary motor provided in an embodiment of this disclosure is shown.

[0036] Figure 11 A schematic diagram of an exemplary focusing curve provided by an embodiment of this disclosure is shown.

[0037] Figure 12A A schematic diagram of an exemplary focusing ring provided in an embodiment of this disclosure is shown.

[0038] Figure 12B A schematic diagram of an exemplary focusing ring provided in an embodiment of this disclosure is shown.

[0039] Figure 13 A schematic diagram of an exemplary focusing ring offset curve provided in an embodiment of this disclosure is shown. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0041] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0042] like Figure 1 As shown, the optical engine includes a main housing 1, a lens 2, a motor 3, a pinion 4, and a mainboard, among other structures. For example, Figure 2 , Figure 3 , Figure 6 As shown, lens 2 includes lens barrel 22, flange 21 and focusing ring 23.

[0043] like Figure 5 As shown, the lens barrel 22 is assembled from lenses 221 with different outer diameters and spacings. Figure 3 , Figure 4 As shown, a protrusion 221 is provided on the outside of the lens barrel 22, such as... Figure 6 , Figure 8 As shown, the focusing ring 23 has a slide rail 231 inside that mates with the protrusion 221. In related technologies, the slide rail 231 is a straight structure. The protrusion 221 and the slide rail 231 are used to install the focusing ring 23 and the lens barrel 22. After the focusing ring 23 and the lens barrel 22 are installed, they are then assembled and fixed to the main housing 1 with the flange 21.

[0044] like Figure 7 , Figure 9 , Figure 10As shown, a gear structure 232 is provided on the outside of the focusing ring 232. The gear structure 232 on the outside of the focusing ring 232 meshes with the pinion 4 for torque transmission. The pinion 4 is locked to the motor 3. The motor 3 converts the electrical signal transmitted from the main board into a specific rotation angle. The rotation of the motor 3 drives the pinion 4, the focusing ring 23, and the lens barrel 22 to rotate to complete the shift focusing.

[0045] In related technologies, such as Figure 8 As shown, the slide rail 231 inside the focusing ring 23 is a straight line design. However, the focusing process of an optical scheme generally follows certain optical equations, such as the optical equation for a 3.5-inch optical engine, which is as follows:

[0046] y = -0.000000003573x 5 +0.000001758230x 4 -0.000347624x 3 +0.035248382000x 2

[0047] -1.927539281x+150.499269,

[0048] Where x is the current image size and y is the distance between the front lens and the lens.

[0049] like Figure 11 As shown, the autofocus curve corresponding to the optical equation of the 3.5-inch optical engine is illustrated. According to... Figure 11 It can be concluded that when the distance between the current lens and the lens is 113-104mm, the image size is 35-85 inches; when the distance between the current lens and the lens is 104-102mm, the image size is 85-120 inches.

[0050] like Figure 11 As shown, when focusing within the autofocus curve for a projection size of 40-80 inches, the lens moves a distance of 111-104mm = 7mm. This indicates a large forward / backward movement of the lens; that is, when the projection size changes from small to medium (40 inches), the lens moves a distance of 7mm. Conversely, when focusing within the autofocus curve for a projection size of 80-120 inches, the lens moves a distance of 104-102mm = 2mm. This indicates a very small forward / backward movement; that is, when the projection size changes from medium to large (40 inches), the lens moves a distance of only 2mm.

[0051] In summary, when adjusting the projection size to 40 inches within the small to medium size range, the lens can easily achieve optimal sharpness by rotating 7mm, meaning each 1mm lens movement corresponds to approximately a 5.71-inch change in projection size. However, when adjusting the projection size to 40 inches within the medium to large size range, the lens can only achieve optimal sharpness by rotating 2mm, meaning each 1mm lens movement corresponds to approximately a 20-inch change in projection size. In other words, when the distance between the lens and the image sensor is 104-102mm, the image size increases dramatically, and translating this size into lens rotation angle makes it extremely difficult to achieve optimal sharpness.

[0052] In view of this, embodiments of the present disclosure provide a focusing component to solve the above-mentioned problems.

[0053] like Figures 1-7 , Figure 9 , Figure 10 As shown, the focusing assembly includes a lens barrel 22, a focusing ring 23, a pinion 4, and a motor 3.

[0054] The lens barrel 22 has a protrusion 221 on its exterior. A focusing ring 23 is mounted on the lens barrel 22. The focusing ring 23 has a slide rail 231 inside that mates with the protrusion 221, such as... Figure 12A , Figure 12B As shown, the slide rail 231 is arc-shaped. A gear structure 232 is provided on the outside of the focusing ring 23. The pinion 4 meshes with the gear structure 232. The motor 3 is locked to the pinion 4 for control of the rotation of the focusing ring 23, thereby completing the focusing.

[0055] In this embodiment, by setting the slide rail inside the focusing ring to an arc shape, during the focusing process, the ratio of the projected image size to the forward and backward movement of the lens is reduced when the projected image is in a small to medium size variation range; and the ratio is increased when the projected image is in a medium to large size variation range. This achieves a uniform linear focusing effect during the focusing process, ensuring that the projected image can be well focused and stop at a clear point regardless of whether the projected image is in a small or large size variation range, thus improving the focusing effect.

[0056] In some embodiments, the arc shape of the slide rail is obtained based on the inverse function of the focusing curve.

[0057] In some embodiments, the focusing curve is determined based on the focal length, the distance between the front lens and the lens element, and the projection ratio, which is obtained based on the projected image distance and the projected screen width. In some embodiments, the projection ratio = projected image distance / projected screen width. Here, the focal length refers to the focal length of the lens.

[0058] The focusing curve is a function, comprising the distance between the front lens and the lens element as a function of the projected image size. It should be noted that different optical engines have different focusing curves. The process of obtaining the focusing curve includes: after determining the lens focal length, simulations can be performed based on parameters such as focal length, distance between the front lens and the lens element, projected image distance, projected image width, and projected image size. This yields multiple sets of information on the distance between the front lens and the lens element, projected image distance, projected image width, and projected image size. The focusing curve is then obtained by fitting this information.

[0059] Taking the focusing curve of a 3.5-inch optical engine as an example, its functional equations include:

[0060] y = -0.000000003573x 5 +0.000001758230x 4 -0.000347624x 3 +0.035248382000x 2

[0061] -1.927539281x+150.499269,

[0062] Where x is the current projection screen size; y is the distance between the front lens and the lens, that is, the total travel distance of the lens's forward and backward movement.

[0063] In this embodiment, after obtaining the focusing curve of the corresponding optical engine, the inverse function curve of the focusing curve, i.e., the focusing ring offset curve, is obtained by performing an inverse function calculation on the focusing curve. Based on this inverse function curve, the arc shape of the slide rail inside the focusing ring can be obtained, such as... Figure 13 As shown.

[0064] In some embodiments, if directly calculating the inverse function of the focusing curve cannot yield a continuous linear function curve, an interpolation algorithm can be used to process the inverse function of the focusing curve to obtain the inverse function curve of the focusing curve, thereby obtaining the arc shape of the slide rail inside the focusing ring.

[0065] In some embodiments, the slide rail includes a first slide rail region and a second slide rail region, the first slide rail region corresponds to the variation range of the first projection size, the second slide rail region corresponds to the variation range of the second projection size, and the variation range of the second projection size is greater than the variation range of the first projection size.

[0066] The slope of the first slide rail region is greater than the reference slope parameter, and the slope of the second slide rail region is less than the reference slope parameter. The reference slope parameter is the slope of the straight line structure formed by connecting the two ends of the slide rail. Specifically, the reference slope parameter is the slope of the straight line structure formed by connecting the two ends of the slide rail, i.e., as... Figure 8 The slope of the linear slide rail is shown when the operation inside the focusing ring is a linear structure.

[0067] like Figure 11 As shown, when the slider inside the focusing ring is a linear structure, when focusing within the range of 40-80 inches (small to medium size) in the autofocus curve, the lens moves a distance of 111-104mm = 7mm. This indicates a large forward / backward movement of the lens; that is, when the size changes by 40 inches (small to medium size), the lens moves a distance of 7mm. When focusing within the range of 80-120 inches (medium to large size) in the autofocus curve, the lens moves a distance of 104-102mm = 2mm. This indicates a very small forward / backward movement; that is, when the size changes by 40 inches (medium to large size), the lens moves a distance of only 2mm.

[0068] In summary, within the small to medium size range, when adjusting the projected image size to 40 inches, the lens can easily achieve optimal sharpness by rotating 7mm, meaning each 1mm lens movement roughly corresponds to a 5.71-inch change in projected image size. However, within the medium to large size range, adjusting the projected image size to 40 inches requires only a 2mm lens rotation, meaning each 1mm lens movement roughly corresponds to a 20-inch change in projected image size. In other words, when the distance between the lens and the image sensor is 104-102mm, the image size increases dramatically, and translating this into a lens rotation angle makes it extremely difficult to achieve optimal sharpness.

[0069] Therefore, in this application, within the range of small to medium size (i.e., the first projected size), the slope of the corresponding first slide rail region needs to be increased so that the slope of the first slide rail region is greater than the reference slope parameter, thereby enabling the lens to focus quickly. Within the range of medium to large size (i.e., the second projected size), the slope of the corresponding second slide rail region needs to be decreased so that the slope of the second slide rail region is less than the reference slope parameter, thereby enabling the lens to focus quickly, thus achieving a uniform linear focusing effect.

[0070] In some embodiments, the first projection size varies within a range of 40-80 inches, and the second projection size varies within a range of 80-120 inches. In this embodiment, for the first projection size variation range of 40-80 inches, the slope of the corresponding first slide rail region needs to be increased so that the slope of the first slide rail region is greater than the reference slope parameter, thereby increasing the projection size change by more than 5.71 inches for every 1mm movement of the lens. For the second projection size variation range of 80-120 inches, the slope of the corresponding second slide rail region needs to be decreased so that the slope of the second slide rail region is less than the reference slope parameter, thereby reducing the projection size change by less than 20 inches for every 1mm movement of the lens, thus achieving a uniform linear focusing effect.

[0071] The variation range of the first projection size and the variation range of the second projection size are not limited to those described in the above embodiments, and can be adjusted according to the user's actual needs.

[0072] In some embodiments, the slope of the first slide rail region and / or the slope of the second slide rail region are determined based on the distance between the front lens and the lens and the radian range of the focusing ring rotation.

[0073] The focusing ring rotates in an arc ranging from 90 to 135 degrees.

[0074] like Figure 7 , Figure 8 As shown, since the movement of the lens forward and backward is driven by the internal slide rail 232 of the focusing ring 23, the arc b = the arc corresponding to the angle of rotation of the lens when the lens moves forward and backward a distance a, and the arc b is the total movement distance. That is, a is constant, the larger the arc b, the slower the focusing process; the smaller the arc b, the faster the focusing process. Therefore, with a fixed motor step angle, the slope of the first slide rail region and / or the slope of the second slide rail region can be determined by setting the distance a between the front lens and the lens element and the arc range b of the focusing ring rotation. Then, by setting the slope of the first slide rail region and / or the slope of the second slide rail region, a uniform linear focusing effect can be achieved.

[0075] In some embodiments, the slope k of the slide rail satisfies k→(1 / 2,+∞).

[0076] Based on the same inventive concept, corresponding to the focusing assembly described in any of the above embodiments, this disclosure also provides an optical engine. The host includes a main housing and an image projection unit disposed on the main housing; and a focusing assembly as described in the above embodiments, the focusing assembly being disposed on the main housing.

[0077] The optical engine of the above embodiments includes the corresponding focusing component in any of the foregoing embodiments and has the beneficial effects of the corresponding focusing component embodiments, which will not be repeated here.

[0078] Based on the same inventive concept, corresponding to any of the above embodiments, this application proposes a projection device, which includes an optical engine and a projection screen as described in the above embodiments, and the projection screen is used to receive the projected image of the optical engine.

[0079] The projection device of the above embodiments includes the corresponding optical engine in any of the foregoing embodiments and has the beneficial effects of the corresponding optical engine embodiments, which will not be repeated here.

[0080] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this disclosure (including the claims) is limited to these examples; within the framework of this disclosure, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this disclosure as described above, which are not provided in detail for the sake of brevity.

[0081] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this disclosure, the provided drawings may or may not show well-known power / ground connections to integrated circuit (IC) chips and other components. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this disclosure, and this also takes into account the fact that the details of implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this disclosure will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuitry) have been set forth to describe exemplary embodiments of this disclosure, it will be apparent to those skilled in the art that the embodiments of this disclosure may be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0082] Although this disclosure has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0083] This disclosure is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A focusing assembly, comprising: The lens barrel has raised dots on the outside; A focusing ring is mounted on the lens barrel. The focusing ring has an internal slide rail that mates with the protrusion. The slide rail is arc-shaped. The focusing ring also has a gear structure on its exterior. The pinion meshes with the gear structure; A motor, locked to the pinion gear, is used to control the rotation of the focusing ring via the pinion gear.

2. The focusing assembly according to claim 1, wherein, The arc shape of the slide rail is obtained based on the inverse function of the focusing curve.

3. The focusing assembly according to claim 2, wherein, The focusing curve includes: the distance between the front lens and the lens as a function of the projected image size.

4. The focusing assembly according to claim 2, wherein, The focusing curve is determined based on the focal length, the distance between the front lens and the lens, and the projection ratio, which is obtained based on the projection image distance and the projection screen width.

5. The focusing assembly according to claim 1, wherein, The slide rail includes a first slide rail area and a second slide rail area. The first slide rail area corresponds to the variation range of the first projection size, and the second slide rail area corresponds to the variation range of the second projection size. The variation range of the second projection size is greater than the variation range of the first projection size. The slope of the first slide rail region is greater than the reference slope parameter, and the slope of the second slide rail region is less than the reference slope parameter. The reference slope parameter is the slope of the straight line structure formed by connecting the two ends of the slide rail.

6. The focusing assembly according to claim 5, wherein, The first projection size varies from 40 to 80 inches, and the second projection size varies from 80 to 120 inches.

7. The focusing assembly according to claim 5, wherein, The slope of the first slide rail region and / or the slope of the second slide rail region are determined based on the distance between the front lens and the lens and the arc range of the focusing ring rotation.

8. The focusing assembly according to claim 5, wherein, The slope k of the slide rail satisfies k→(1 / 2,+∞).

9. An optical engine, comprising: The host includes a main housing and an image projection unit disposed on the main housing; as well as, The focusing assembly as described in any one of claims 1-8, wherein the focusing assembly is disposed on the main housing.

10. A projection device, comprising: The optical mechanism as described in claim 9; as well as, A projection screen is used to receive the projected image from the optical engine.

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