Optical device
Through optical device design and the use of diffuse light paths and light convergence mechanisms, the problem of insufficient imaging of existing scanning equipment in scenarios with high image quality requirements is solved, and improvements in high resolution, color fidelity and image uniformity are achieved, achieving a telecentric effect.
Patent Information
- Application Number
- CN202422853849.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-11-21
AI Technical Summary
In scenarios where high image quality is required, existing scanning equipment finds it difficult to simultaneously meet requirements such as high resolution, color fidelity, image brightness uniformity, size ratio presentation of scanned objects, and text line sharpness.
It adopts an optical device design, including a light source, a first beam splitter, a curved reflector, a lens module and a photosensitive module. Through the path design of diffuse light and the light converging mechanism, it achieves a telecentric effect of light, reduces aberrations and improves imaging quality.
It achieves high-quality imaging and telecentric effect, improves the image resolution, color fidelity and image brightness uniformity of the scanning equipment, and ensures the sharpness of text and lines.
Smart Images
Figure CN223347134U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to an optical device, in particular to an optical device with a telecentric effect. Background Art
[0002] In daily life and modern office work, there is a common need to photograph or scan objects or documents, converting them from physical objects into digital data for subsequent reading, processing, or sharing on electronic devices. Currently, scanners and printers are often used to convert paper documents, images, and photos into digital data.
[0003] With advancements in photography and scanning technology, the requirements for digitized data image quality are becoming increasingly stringent to meet diverse needs. Image quality requirements include, but are not limited to, high resolution, color fidelity, image brightness uniformity, proportional representation of scanned or photographed objects, and sharpness of text and lines. Utility Model Content
[0004] In view of this, the present invention provides an optical device comprising a light source, a first beam splitter, a curved reflector, a lens module, and a photosensitive module. The first beam splitter is located downstream of the light path of the light source, and the first beam splitter has a first side and a second side that are opposite to each other. The curved reflector is located downstream of the light path of the first side of the first beam splitter, and the curved reflector has a curved surface facing the first side of the first beam splitter, the curved surface has a curved surface center, and the curved surface is symmetrical about the curved surface center. The lens module is located downstream of the light path of the second side of the first beam splitter and faces the second side of the curved reflector. The lens module has an optical axis, and the optical axis is aligned with the curved surface center. The photosensitive module is located downstream of the light path of the lens module.
[0005] In one embodiment, the light source generates a light beam, and the light beam reaches the first side of the first beam splitter after being reflected by the object.
[0006] In one embodiment, after being reflected by the object, the light is sequentially reflected on the first side of the first beam splitter and the curved surface of the curved reflector, and passes through the first side and the second side of the first beam splitter to reach the lens module.
[0007] In one embodiment, the optical axis of the lens module is parallel to the light reflected from the first side of the first beam splitter to the curved reflector.
[0008] In one embodiment, the lens module has an entrance pupil facing the second side of the first beam splitter, and light is converged at the entrance pupil.
[0009] In one embodiment, the optical device further includes a processor electrically connected to the photosensitive module.
[0010] In one embodiment, the photosensitive module receives light and generates an image signal, and the processor receives the image signal and generates an image of the object.
[0011] In one embodiment, the curved surface of the curved reflector is a spherical surface.
[0012] In one embodiment, the curved surface of the curved reflector is a parabola. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the following describes in detail the specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:
[0014] Figure 1 FIG. 4 is a schematic side view of an optical device according to an embodiment.
[0015] Figure 2 yes Figure 1 A top view schematically illustrating an embodiment.
[0016] Figure 3 FIG. 4 is a schematic side view of an optical device according to another embodiment.
[0017] Figure 4 FIG. 4 is a side view schematic diagram of an optical device according to another embodiment, illustrating a situation where the light generated by the light source does not directly illuminate the photographing surface of the object.
[0018] Figure 5 FIG. 4 is a side view schematic diagram of an optical device according to yet another embodiment, illustrating a situation where the photographing surface of an object is a smooth plane.
[0019] In the picture:
[0020] 10: Light Source
[0021] 12: First spectroscope
[0022] 121: First side
[0023] 123: Second side
[0024] 125: Cube Beamsplitter
[0025] 126:Right-angle prism
[0026] 126a: Page 1
[0027] 126b: Side 2
[0028] 127: Plate beam splitter
[0029] 13: Second beam splitter
[0030] 14:Curved reflector
[0031] 141: Surface
[0032] 143: First surface
[0033] 143a: First end
[0034] 145: Second surface
[0035] 145a: Second end
[0036] 16: Lens module
[0037] 161: Entrance to the pupil
[0038] 18: Photosensitive module
[0039] 20: Object
[0040] 201: Shooting Surface
[0041] 203: Translucent Platform
[0042] 22: Processor
[0043] C: Surface center
[0044] d: Light offset
[0045] F1: Focus point
[0046] F2: Focus
[0047] L i :Light
[0048] L d :Diffuse light
[0049] L d1 :Light
[0050] L d2 :Light
[0051] L d3 :Light
[0052] L dt :Light
[0053] L dt1 :Light
[0054] L dt2 :Light
[0055] L r :Reflected light
[0056] L rt :Light
[0057] L rt1 :Light
[0058] L rt2 :Light
[0059] OA: Optical Axis
[0060] θ1: first angle
[0061] θ2: second angle DETAILED DESCRIPTION
[0062] refer to Figure 1 and Figure 2 , Figure 1 is a side view schematic diagram of an optical device according to an embodiment, Figure 2 for Figure 1 A top view of an embodiment. The optical device includes a light source 10, a first beam splitter 12, a curved reflector 14, a lens module 16, and a photosensitive module 18. The first beam splitter 12 is located downstream of the light path of the light source 10 and has a first side 121 and a second side 123 that are opposite to each other. The curved reflector 14 is located downstream of the first side 121 of the first beam splitter 12 in the light path. The curved reflector 14 has a curved surface 141, with the curved surface 141 facing the first side 121 of the first beam splitter 12. The curved surface 141 has a curvature center C, which is the center of symmetry of the curved surface 141.
[0063] Lens module 16 is located downstream of second side 123 of first beam splitter 12 in the optical path, and faces second side 123 of curved reflector 14. Lens module 16 has an optical axis OA aligned with the center C of curved surface 141. Photosensitive module 18 is located downstream of lens module 16 in the optical path.
[0064] In some embodiments, the optical device is used to photograph the object 20 to obtain an image of the object 20. During the photographing process, the light source 10 generates light L i The light L is incident on the shooting surface 201 of the object 20. It should be emphasized that the shooting surface 201 must be a rough surface that allows the light to diffuse. i The diffuse light L is generated when the light is irradiated on the shooting surface 201. d , where the diffuse light L d There is no specific directionality, so a portion of the diffused light L reaches the first side 121 of the first beam splitter 12 and moves toward the first beam splitter 12. d (Take the diffuse light in the direction perpendicular to the shooting surface 201 as an example) which will be reflected by the first beam splitter 12 and become the light L in the figure d1 . Light L d1After reaching the curved reflector 14, the light will be reflected by the curved surface 141 of the curved reflector 14 and reach the first side 121 of the first beam splitter 12 again. A portion of the light L d1 Will be reflected by the first beam splitter 12 (not shown), and part of the light L d1 It will pass through the first side 121 and the second side 123 of the first beam splitter 12 and become the light L in the figure. d2 . Light L d2 It will continue to move forward and reach the lens module 16.
[0065] Specifically, in some embodiments, the object 20 to be photographed by the optical device has a surface to be photographed and formed into an image (hereinafter referred to as the photographing surface 201). The object 20 can be placed above the first beam splitter 12 (eg, Figure 1 The light source 10 may be located between the object 20 and the first beam splitter 12 and face the photographing surface 201 of the object 20, so as to generate a light beam L at the light source 10. i When the light source 10 emits light L toward the shooting surface 201 of the object 20 i Unless otherwise specified, the light source 10 referred to in this specification is a line light source.
[0066] Re-reference Figure 2 In some embodiments, the light source 10 emits light L toward the shooting surface 201. i After that, the light L i Diffusion (diffuse reflection) will occur on the shooting surface 201, and part of the diffuse light L d , for example, the diffuse light L perpendicular to the shooting surface 201 d The light will reach the first side 121 of the first beam splitter 12 .
[0067] The first beam splitter 12 allows part of the diffuse light L d Penetrating and partially diffused light L d Reflected, diffuse light L d When reaching the first side 121 of the first beam splitter 12, part of the diffuse light L d The light is reflected from the first side 121 to the curved reflector 14 and is defined as L d1 .Reference Figure 1 In some embodiments, when the object 20 is placed above the first beam splitter 12, a first angle θ1 may be defined between the shooting surface 201 and the first side 121 of the first beam splitter 12. The angle of the first angle θ1 is greater than 0 degrees, so that the diffused light L diffused by the shooting surface 201 is dThe light will enter the first side 121 of the first beam splitter 12 at the second angle θ2 as the incident angle, and will be reflected out of the first side 121 at the second angle θ2 as the reflection angle based on the principle that the reflection angle is equal to the incident angle, wherein the second angle θ2 is also greater than 0 degrees. In this way, the stray light L can be prevented from being scattered. d When the light reaches the first side 121 of the first beam splitter 12 , it cannot be reflected at the first side 121 .
[0068] Specifically, although the diffuse light L d There is no directionality, but if the light source 10 is incident at an angle close to parallel to the shooting surface 201, it is possible to make the diffuse light L traveling perpendicular to the shooting surface 201 d The intensity is too weak, so the light source 10 in the figure is incident at an angle of 45 degrees. However, it should be emphasized that the present invention is not limited to this, and the light source 10 can also be incident at an angle of 30 degrees or 60 degrees, as long as it can generate diffuse light L with sufficient intensity. d It is sufficient to obtain imaging quality that meets the specifications.
[0069] In some embodiments, the first beam splitter 12 can be implemented as a cube beam splitter 125 or a plate beam splitter 127. Figure 3 , Figure 3 FIG. 4 is a schematic side view of an optical device according to another embodiment. Figure 3 The first beam splitter 12 is realized by a cubic beam splitter 125. The cubic beam splitter 125 can be composed of two right-angle prisms 126. The first side 121 and the second side 123 of the first beam splitter 12 are the inclined surfaces of the two right-angle prisms 126, and the two inclined surfaces are attached to each other to form a cubic shape. Figure 1 , Figure 1 The first beam splitter 12 is implemented by a plate beam splitter 127, which is a plate-shaped planar lens. The two opposing planes of the plate-shaped planar lens are the first side 121 and the second side 123 of the first beam splitter 12. Whether using the cube beam splitter 125 or the plate beam splitter 127, when the object 20 is placed toward the first beam splitter 12, the first angle θ1 defined between the imaging surface 201 and the first side 121 is 45 degrees.
[0070] In the embodiment where the first angle θ1 is 45 degrees, when the first side 121 receives the diffuse light L reflected from the shooting surface 201 and perpendicular to the shooting surface 201 d When the diffuse light L d The incident angle of the first side 121 and the diffuse light L d The reflection angle reflected at the first side 121, that is, the second angle θ2, is also 45 degrees. At this time, the diffuse light L originally propagating along the X direction can be diverted through the first side 121. dChange to propagate along the Y direction (that is, become L in the figure d1 ), so that the components downstream of the optical path of the first side 121 can be arranged in a direction with sufficient space in the Y direction (for example Figure 1 curved reflector 14, lens module 16, etc.).
[0071] In addition, the curved reflector 14 and the first beam splitter 12 can be placed on the same horizontal plane (e.g. Figure 1 The curved reflector 14 is located at the same position as the first beam splitter 12 on the X axis, and the curved surface 141 of the curved reflector 14 can completely receive the light L reflected from the first side 121. d1 .
[0072] refer to Figure 2 In some embodiments, the curved surface 141 of the curved reflector 14 may be a concave surface, so that the parallel light rays Ld1 converge after being reflected by the curved surface 141 .
[0073] In some embodiments, curved surface 141 is a concave spherical surface or paraboloid, which is not a limitation herein. Curved surface 141 includes a first curved surface 143 and a second curved surface 145. The first curved surface 143 and the second curved surface 145 respectively have a first end 143a and a second end 145a. The first end 143a of the first curved surface 143 is connected to the second end 145a of the second curved surface 145, and the area between the first end 143a and the second end 145a serves as the center of curvature C of curved surface 141. In some embodiments, the center of curvature C may be any point on the X-axis between the first end 143a and the second end 145a.
[0074] The first curved surface 143 and the second curved surface 145 each have a curvature. The curvature of the first curved surface 143 and the curvature of the second curved surface 145 are the same. The first curved surface 143 and the second curved surface 145 are symmetrical to each other with the curved surface center C as the symmetry center.
[0075] As mentioned above, the light L d1 After being reflected by the curved reflector 14, the Figure 1 In some embodiments, the light L d1 Converge at the focal point F1, then refer to Figure 3 In other embodiments, the light L d1 Converges at focus F2. As previously mentioned, the curved surface 141 of the curved reflector 14 is concave. Focus F2 is the focal point (Focus Point) where the parallel light is focused after being reflected from the curved surface 141. Both focus points F1 and F2 are aligned with the center C of the curved surface of the curved reflector 14. However, focus points F1 and F2 are located at different positions on the X-axis. The following will describe focus points F1 and F2 in detail.
[0076] At Figure 2As can be seen in the embodiments, the light L d1 Before converging at the focal point F1 or F2, the light L d1 The light passing through the first side 121 and the second side 123 of the first beam splitter 12 is defined as the light L. d2 In some embodiments, the first beam splitter 12 is made of glass, and its refractive index is greater than that of air. d1 When passing through the first beam splitter 12 , light first enters the optically denser medium (glass) from the optically rarer medium (air), and then enters the optically rarer medium (air) from the optically denser medium (glass).
[0077] Re-reference Figure 1 At this time, the first beam splitter 12 is realized by the flat beam splitter 127, and the light L d1 When the light L enters the first side 121 of the flat beam splitter 127 from the curved reflector 14, it enters the glass from the air. d1 The incident angle of the light L on the first side 121 is greater than 0 degrees. d1 The light L is refracted when entering the first side 121 and passing through the second side 123. d1 The propagation direction changes, so that the light L passing through the second side 123 d2 With respect to the light L entering the first side 121 d1 A light deviation d is generated. The deflected light L d2 The converged position is the focal point F1.
[0078] refer to Figure 3 In this case, the first beam splitter 12 is implemented by a cubic beam splitter 125. The two right-angle prisms 126 in the cubic beam splitter 125 include not only an inclined surface as the first side 121 or the second side 123, but also a first surface 126a and a second surface 126b. d1 When the light L enters the cubic beam splitter 125 from the curved reflector 14, it will first pass through the first surface 126a of one of the right-angle prisms 126. d1 When the light enters the first surface 126a, it enters the glass from the air. d1 The incident angle of the light L on the first surface 126a is 0 degrees. d1 There is no refraction in the cube beam splitter 125, and the light L d1 The direction of propagation remains unchanged.
[0079] In light L d1 After passing through the first side 121 and the second side 123 in sequence, the light beam passes through the second surface 126b of another right angle prism 126 in the cube beam splitter 125 and becomes the light beam L d2 , light L d1The incident angle when passing through the second surface 126b is also 0 degrees, so that the light L d1 Even if the light enters the air from the glass, it will not be refracted. The light L passing through the second surface 126b will not be refracted. d2 The direction of propagation remains unchanged. At this time, the light L d2 The converged position is the focus F2.
[0080] Re-reference Figure 1 or Figure 2 In some embodiments, the lens module 16 in the optical device has an entrance pupil 161, which is located on the optical axis OA of the lens module 16 and faces the second side 123 of the first beam splitter 12. The lens module 16 aligns the optical axis OA with the center C of the curved surface of the curved reflector 14, and the entrance pupil 161 is located at the aforementioned focal point F1 or focal point F2. The photosensitive module 18 is disposed downstream of the optical path of the lens module 16 to receive the light L after passing through the lens module 16. d3 And the light L d3 In this embodiment, the lens module 16 is arranged at the position relative to the center C of the curved surface, the focus point F1 or the focus point F2 to reduce the subsequent light L d3 The aberration generated after the light enters the photosensitive module 18 improves the quality of the light received by the photosensitive module 18 .
[0081] Re-reference Figure 3 In some embodiments, the optical device further includes a processor 22 , which is electrically connected to the photosensitive module 18 . The photosensitive module 18 transmits the generated image signal to the processor 22 , and the processor 22 analyzes the image signal to generate an image of the shooting surface 201 of the object 20 .
[0082] In some embodiments, the light L received by the photosensitive module 18 through the first beam splitter 12, the curved reflector 14, and the lens module 16 d3 For the parallel light rays reflected by the photographing surface 201 of the object 20 , the image generated by the processor 22 will be an orthogonal projection of the object 20 , thereby achieving a telecentric effect.
[0083] Continued reference Figure 3 In some embodiments, the optical device includes a light-transmitting platform 203 . The light-transmitting platform 203 is disposed toward the first side 121 of the first beam splitter 12 and can be disposed above the first beam splitter 12 (along the X direction).
[0084] As mentioned above, the object 20 can be placed on the light-transmitting platform 203, and the shooting surface 201 of the object 20 can face the light-transmitting platform 203. The light-transmitting platform 203 can have a high light transmittance so that most of the light L generated by the light source 10 can be iFor example, the light-transmitting platform 203 can be made of glass, in particular, can be made of soda-lime glass. The transmittance of soda-lime glass for visible light can reach more than 90%, that is, when the light L generated by the light source 10 i When reaching the light-transmitting platform 203 made of blue plate glass, more than 90% of the light L i The light can pass through the light-transmitting platform 203 and illuminate the shooting surface 201 .
[0085] Reference Figure 4 , compared to Figure 1 In the embodiment, the light source 10 generates light L i Instead of directly irradiating the shooting surface 201 of the object 20, the light first irradiates a second beam splitter 13, and then a portion of the light L i The light is reflected by the second beam splitter 13 and illuminates the shooting surface 201 of the object 20, thereby generating a diffuse light L d A portion of the diffuse light L d (For example Figure 4 The diffuse light L that advances in a direction perpendicular to the photographing surface 201 d ) will reach the second beam splitter 13 and pass through the second beam splitter 13 and enter the first side 121 of the first beam splitter 12 located downstream of the second beam splitter 13 at an incident angle equal to the second included angle θ2. Here, the light that passes through the second beam splitter 13 along the negative X direction in the figure is defined as the light L dt The light L reaching the first side 121 of the first beam splitter 12 dt It will be reflected by the first beam splitter 12 and become the light L in the figure dt1 , where the reflection angle = incident angle = θ2. Light L dt1 After reaching the curved reflector 14, it will be reflected by the curved surface 141 of the curved reflector 14 and reach the first side 121 of the first beam splitter 12 again. A portion of the light Ldt1 will pass through the first side 121 and the second side 123 of the first beam splitter 12 and become the light L in the figure. dt2 . Light L dt2 The light continues to move forward, passes through the lens module 16 , and is imaged by the photosensitive module 18 .
[0086] Reference Figure 5 , Figure 5 The embodiment shown is for explaining the case where the photographing surface 201 of the object 20 is a smooth plane. Figure 4 The light source 10 generates a light beam L i Instead of directly irradiating the shooting surface 201 of the object 20, the light first irradiates a second beam splitter 13, and then a portion of the light L iThe reflected light L is reflected by the second beam splitter 13 and illuminates the shooting surface 201 of the object 20, thereby generating a reflected light L r . Reflected light L r The light travels in a direction perpendicular to the photographing surface 201 and reaches the second beam splitter 13, and then passes through the second beam splitter 13 and enters the first side 121 of the first beam splitter 12 located downstream of the second beam splitter 13 at an incident angle equal to the second included angle θ2. Here, the light that passes through the second beam splitter 13 in the negative X direction in the figure is defined as the light L. rt The light L reaching the first side 121 of the first beam splitter 12 rt It will be reflected by the first beam splitter 12 and become the light L in the figure rt1 , where the reflection angle = incident angle = θ2. Light L rt1 After reaching the curved reflector 14, the light will be reflected by the curved surface 141 of the curved reflector 14 and reach the first side 121 of the first beam splitter 12 again. A portion of the light L rt1 It will pass through the first side 121 and the second side 123 of the first beam splitter 12 and become the light L in the figure. rt2 . Light L rt2 The light continues to move forward, passes through the lens module 16 , and is imaged by the photosensitive module 18 .
[0087] In some embodiments, the light source 10 may be a xenon lamp or a cold light tube.
[0088] In some embodiments, the lens module 16 may include one or more lenses, and the lens may be implemented by a spherical lens, an aspheric lens, a Poisson aspheric lens, a mirror lens, a lens lens, a focal length adjustable lens, a continuous focal length lens, etc.
[0089] In some embodiments, the photosensitive module 18 may be a photosensitive device such as a CMOS photoreceptor (Complementary Metal-Oxide-Semiconductor), a CCD photoreceptor (Charge-Coupled Device), or a BSI photoreceptor (Back Side Illuminated) that converts photons into electronic signals.
[0090] In summary, the optical device can receive parallel light reflected by the object 20 to obtain an orthogonal projection of the object 20 , achieving the effect of a telecentric lens. The optical device can also reduce aberrations in the obtained image, thereby improving the imaging quality of the photosensitive module 18 .
[0091] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make slight modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the definition of the claims.
Claims
1. An optical device, characterized in that: include: a light source; a first beam splitter having a first side and a second side opposite to each other; a curved reflector located downstream of the optical path of the first side of the first beam splitter, the curved reflector having a curved surface facing the first side of the first beam splitter, the curved surface having a curved center and being symmetrical about the curved center; a lens module located downstream of the optical path of the second side of the first beam splitter and facing the second side of the curved reflector, the lens module having an optical axis aligned with the center of the curved surface; and A photosensitive module is located downstream of the optical path of the lens module.
2. The optical device according to claim 1, wherein The light source generates a light beam, and the light beam reaches the first side of the first beam splitter after being reflected by an object.
3. The optical device according to claim 2, wherein After being reflected by the object, the light is sequentially reflected on the first side of the first beam splitter and the curved surface of the curved reflector, and passes through the first side and the second side of the first beam splitter to reach the lens module.
4. The optical device according to claim 3, wherein The optical axis of the lens module is parallel to the light reflected from the first side of the first beam splitter to the curved reflector.
5. The optical device according to claim 4, wherein The lens module has an entrance pupil facing the second side of the first beam splitter, and the light converges at the entrance pupil.
6. The optical device according to claim 5, wherein The device further comprises a processor electrically connected to the photosensitive module. The photosensitive module receives the light and generates an image signal. The processor receives the image signal and generates an image of the object.
7. The optical device according to claim 1, wherein The invention also comprises a front first beam splitter, which is arranged downstream of the optical path of the light source and upstream of the optical path of the first beam splitter.
8. The optical device according to claim 1, wherein The curved surface of the curved reflector is a spherical surface.
9. The optical device according to claim 1, wherein The curved surface of the curved reflector is a parabola.