Optical imaging system, camera module and electronic equipment

Abstract

The invention relates to the technical field of optical imaging, and discloses an optical imaging system, a camera module and electronic equipment, the optical imaging system comprises a lens assembly, an imaging assembly and a prism assembly, the prism assembly is provided with an incident plane and an emergent plane which are located on the same side, the lens assembly directly faces the incident plane, and the imaging assembly directly faces the emergent plane. An ink coating area and a stray light improving area used for improving stray light are formed on the prism assembly, and light is reflected for multiple times in the prism assembly after being emitted to the incident plane from the lens assembly and is reflected to the emergent plane after passing through the stray light improving area. According to the invention, the stray light improving area is arranged, and the light blocking area is formed in the prism, so that the light path emitted to the outside of the working surface is subjected to diffuse reflection, the continuous reflection intensity of an invalid light path is effectively reduced, the generation of stray light, ghosting and glare is reduced, and the imaging quality is improved.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and particularly to an optical imaging system, a camera module, and an electronic device. Background Art

[0002] An optical imaging system is an instrument based on the principle of light refraction. It collects and focuses the light of an object through a lens at a point to form a clear image. Therefore, it is often used in various fields such as camera modules, microscopes, and various industrial inspections.

[0003] The optical imaging system of a camera module mainly consists of a lens assembly, a prism assembly, and an image sensor. Through the lens combination inside the lens assembly, the light of the scene is accurately focused on the image sensor by refraction to form an inverted real image, and then the image sensor converts the optical signal into a dot signal to generate an image. As a core component in the optical imaging system, the prism assembly is used to accurately turn or split the optical path. It is often used in periscope lenses to change the light direction to achieve telephoto compression, and can also participate in color separation or polarization processing. However, due to the existence of multiple air-glass interfaces in the prism, including the incident surface and the exit surface, even if an anti-reflection film is coated on the surface of the prism assembly, residual reflected light will still be generated at the edge of the prism assembly, and ghost images will be formed by internal reflection and refraction in the prism assembly; if the total reflection failure occurs due to coating defects, contamination, or angle deviation on the total reflection inclined surface, penetrating stray light will be directly generated. In addition, the environmental stray light scattering on the non-working surface of the prism assembly and the newly added complex reflection paths after the optical path is folded will make the imaging light more likely to invade the sensor, resulting in unpredictable glare or contrast reduction. Summary of the Invention

[0004] Aiming at the deficiencies of the above-mentioned prior art, the technical problem to be solved by the present invention is: to provide an optical imaging system, a camera module, and an electronic device to solve the problem of a large amount of stray light caused by light reflection on the prism assembly.

[0005] To solve the above technical problem, a technical solution adopted by the present invention is: to provide an optical imaging system including a lens assembly, an imaging assembly, and a prism assembly. The prism assembly has an incident surface and an exit surface on the same side. The lens assembly faces the incident surface, and the imaging assembly faces the exit surface. An ink-coated area and a stray light improvement area for improving stray light are formed on the prism assembly. Light travels from the lens assembly to the incident surface, is reflected multiple times in the prism assembly, and is reflected to the exit surface after passing through the stray light improvement area.

[0006] Further, after light enters the prism assembly from all directions through the incident surface, it is reflected to form several different optical paths. The optical paths corresponding to both sides of the imaging assembly are respectively configured as a first optical path and a second optical path. The first optical path and the second optical path formed within the prism assembly overlap and intersect to form an intersection area, and the stray light improvement area is correspondingly arranged at the intersection area.

[0007] Further, the prism assembly has a first reflecting surface, a second reflecting surface, and a third reflecting surface. The second reflecting surface is located between and on the same side as the incident surface and the exit surface. External light enters the prism assembly through the incident surface and then sequentially irradiates the first reflecting surface, the stray light improvement area, the second reflecting surface, and the third reflecting surface and then exits through the exit surface, or external light enters the prism assembly through the incident surface and then sequentially irradiates the first reflecting surface, the second reflecting surface, the stray light improvement area, and the third reflecting surface and then exits through the exit surface.

[0008] Further, the prism assembly includes a first prism in the shape of a right trapezoid and a second prism in the shape of a right trapezoid. The right-angled surfaces corresponding to the right angles of the first prism and the second prism are adhesively connected to form the stray light improvement area. The stray light improvement area includes a silk-screen printing area for blocking stray light and a light-transmitting area for allowing light to pass through and complementary to the silk-screen printing area. A continuous wavy boundary line for forming diffuse reflection of light is formed between the silk-screen printing area and the light-transmitting area.

[0009] Further, the silk-screen printing area has a U-shaped structure and includes a full-blocking section that blocks the bottom of the right-angled surface and semi-blocking sections that block both sides of the right-angled surface from both sides of the full-blocking section towards the top. The light-transmitting area is located between the two semi-blocking sections, and the boundary line between the light-transmitting area and the full-blocking section corresponds to the lowest point of the intersection area.

[0010] Further, the boundary line is formed by alternately and staggeredly connecting a plurality of arcs with a radius of 0.05 mm.

[0011] Further, the prism assembly includes a third prism. The third prism has a bottom surface on the side facing away from the incident surface and the exit surface. The stray light improvement area includes a first light-blocking groove recessed in the bottom surface and extending to the intersection area and second light-blocking grooves symmetrically recessed on both sides of the third prism and staggered with the first light-blocking groove. The first light-blocking groove has a first converging side, and a plurality of continuous first wavy structures for forming diffuse reflection of light are formed on the first converging side, and the first converging side corresponds to the lowest point of the intersection area; Both the first light-blocking groove and the second light-blocking groove are coated with light-blocking materials to form light-blocking areas at the bottom and both sides of the optical path.

[0012] Further, the stray light improvement area further includes a third light blocking groove and a fourth light blocking groove formed on the bottom surface and arranged on both sides of the first light blocking groove along the optical path, and a plurality of continuous second wave structures for forming diffuse reflection of light are formed on the third light blocking groove and / or the fourth light blocking groove.

[0013] The present invention also provides an imaging module, including a bracket, an anti-shake motor, a lens assembly, an imaging assembly, and a prism assembly. The bracket has a mounting surface, and a mounting groove is recessed on the mounting surface. The prism assembly is mounted in the mounting groove. The anti-shake motor is arranged on one side of the mounting surface and faces the incident surface, the imaging assembly is arranged on the other side of the mounting surface and faces the exit surface, and the lens assembly is mounted on the anti-shake motor.

[0014] The present invention also provides an electronic device including the optical imaging system described in any one of the above.

[0015] The optical imaging system, imaging module, and electronic device of the present invention at least have the following beneficial effects: By setting the stray light improvement area, a light blocking area is formed inside the prism, so that the optical path directed outside the working surface is diffusely reflected, effectively reducing the continuous reflection intensity of the invalid optical path, reducing the generation of stray light, ghost images, and glare, and improving the imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present application, and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0017] Figure 1 is a front view structure diagram of the optical imaging system of the present invention;

[0018] Figure 2 is a structure diagram of the prism assembly of Embodiment 1 of the present invention;

[0019] Figure 3 is a front view structure diagram of the prism assembly of the present invention;

[0020] Figure 4 is a structure diagram of the second prism of the present invention;

[0021] Figure 5 is a structure diagram of a part of the optical path of the optical imaging system of Embodiment 1 of the present invention;

[0022] Figure 6 is an irradiance distribution diagram of the light received by the image sensor under various optical paths of the optical imaging system of Embodiment 1 of the present invention;

[0023] Figure 7 is a structure diagram of the prism assembly of Embodiment 2 of the present invention;

[0024] Figure 8 Schematic front view of the prism assembly of the present invention;

[0025] Figure 9 Schematic view of the prism assembly of the present invention (from another angle);

[0026] Figure 10 is Figure 9 Enlarged schematic view of part A shown;

[0027] Figure 11 Schematic views of the optical imaging system of the present invention under four optical paths C1 - C4;

[0028] Figure 12 Irradiance distribution diagrams of the light received by the image sensor of the optical imaging system of the present invention under four optical paths C1 - C4;

[0029] Figure 13 Schematic view of the camera module of the present invention;

[0030] Figure 14 Half - section schematic view of the camera module of the present invention;

[0031] Figure 15 Exploded view of the camera module of the present invention;

[0032] Figure 16 Schematic view of the dust cover of the present invention;

[0033] Figure 17 Schematic view of the bracket of the present invention.

[0034] The meanings of the reference numerals in the drawings are as follows:

[0035] Lens assembly 1, reinforcement block 2, fitting groove 21, prism assembly 3, incident surface 311, exit surface 312, first reflection surface 313, second reflection surface 314, third reflection surface 315, top surface 321, bottom surface 322, first side surface 323, second side surface 324, third side surface 325, fourth side surface 326, inked area 33, first inked part 331, second inked part 332, third inked part 333, fourth inked part 334, fifth inked part 335, sixth inked part 336, intersection area 34, lowest point 341, first prism 351, second prism 352, third prism 353, stray light improvement area 36, silk-screened area 361, fully blocked section 3611, semi-blocked section 3612, light-transmitting area 362, boundary line 363, first light-blocking groove 364, first converging side 3641, second light-blocking groove 365, second converging side 3651, third light-blocking groove 366, fourth light-blocking groove 367, third converging side 3671, first wave structure 368, arc surface 3681, second wave structure 369, bracket 4, mounting surface 41, mounting groove 42, anti-shake motor 5, imaging assembly 6, image sensor 61, chip carrier 62, filter 63, circuit board 64, dust cover 7. Detailed implementation manners

[0036] The present invention will be further described below with reference to the accompanying drawings.

[0037] Please refer to Figures 1 to 12 , the optical imaging system of the present invention includes a lens assembly 1, an imaging assembly 6, and a prism assembly 3. The lens assembly 1 focuses the scene light onto the prism assembly 3 through refraction, and the prism assembly 3 changes the light direction by reflecting the light, so that after long focal compression, the light is focused onto the imaging assembly 6, and the imaging assembly 6 converts the optical signal into an electrical signal and then generates an image.

[0038] In this embodiment, the lens assembly 1 includes a lens carrier and a plurality of lenses mounted on the lens carrier. The lenses can be set to more than two, such as four, and are arranged in sequence along the optical axis direction and arranged with the prism assembly 3. In one embodiment, the two lenses close to the object side surface have positive optical power, and the two lenses close to the prism assembly 3 have negative optical power. One side of the two lenses with positive optical power facing the object side surface can be a convex surface to ensure that the light is converged after entering from the object side surface, while the two lenses with negative optical power slow down the degree of light deflection, so that the light transitions smoothly. The lens assembly 1 is a prior art, and any lens assembly 1 for a camera module can be referred to, especially the lens assembly 1 of a periscope camera module, which will not be elaborated here.

[0039] In this embodiment, the imaging assembly 6 includes an image sensor 61 (or chip) for converting an optical signal into an electrical signal. Among them, the image sensor 61 is divided into two sides with a first side close to the incident surface 311 and a second side far from the incident surface 311.

[0040] In this embodiment, the prism assembly 3 has an incident surface 311 and an exit surface 312. The lens assembly 1 is disposed opposite to the incident surface 311 and the imaging assembly 6 is disposed opposite to the exit surface 312, so that the lens assembly 1 and the imaging assembly 6 are located on the same side of the prism assembly 3. The prism assembly 3 is trapezoidal and the incident surface 311 and the exit surface 312 are located on the same side, effectively controlling the thickness of the prism assembly 3. Light travels from the lens assembly 1 to the incident surface 311, and after multiple reflections within the prism assembly 3, it travels through the exit surface 312 to the imaging assembly 6. The outer surfaces of the prism assembly 3 are respectively a top surface 321, a bottom surface 322, a first side surface 323, a second side surface 324, a third side surface 325, and a fourth side surface 326. Among them, the top surface 321 and the bottom surface 322 are distributed oppositely and parallel, and the top surface 321 and the bottom surface 322 are distributed with one long and one short. The first side surface 323 and the second side surface 324 are parallel and symmetrically distributed on both sides of the top surface 321 and the bottom surface 322 along the width, and the third side surface 325 and the fourth side surface 326 are symmetrically distributed on both sides of the top surface 321 and the bottom surface 322 along the length, so that the prism assembly 3 has an isosceles trapezoidal structure. It should be noted that the structure of the prism assembly 3 is not limited to a trapezoid, and it can also be composed of multiple triangular prisms to form a special-shaped structure. It is possible to ensure that the incident surface 311 and the exit surface 312 are located on the same side or different sides. Finally, it is only necessary to focus the light on the imaging assembly 6 after it exits from the exit surface 312. The angles between the two sides of the top surface 321 of the prism assembly 3 and the third side surface 325 and the fourth side surface 326 are about 33°.

[0041] On the prism assembly 3, in order to reduce light energy loss, improve imaging quality, and reduce stray light during use, ink can be applied to the surface of the prism assembly 3 by means of silk screen printing or other methods to form an inked area 33. The inked area 33 is coated with an AR film. The inked area 33 includes ink applied to the top surface 321, the bottom surface 322, the first side surface 323, the second side surface 324, the third side surface 325, and the fourth side surface 326. Specifically, the inked area 33 includes a first inked portion 331 formed on the top surface 321, a second inked portion 332 formed on the bottom surface 322, a third inked portion 333 formed on the first side surface 323, a fourth inked portion 334 formed on the second side surface 324, a fourth inked portion 334 formed on the third side surface 325, and a fifth inked portion 335 formed on the fourth side surface 326. A first reflection area is left at the middle position of the first ink-coated portion 331. The first reflection area has a first part, a second part and a third part that are gradually widened along the length direction of the prism assembly 3, wherein the first part, the second part and the third part are all rectangular structures, wherein the first part is the incident surface 311 and is set corresponding to the size of the lens assembly 1, the third part is the exit surface 312 and is set corresponding to the size of the imaging assembly 6, thereby controlling the light input and light output, the ink-coated portion blocks unnecessary stray light, and the second part is configured as a second reflection surface 314. In this way, the ink-coated area 33 ensures the formation of the first reflection area, blocks the part of the top surface 321 located outside the first reflection area, so that the light emitted from the inside of the prism assembly 3 to the edge is absorbed, reducing the formation of stray light. At the same time, the first reflection area with one side wide (referring to the third part) and one side narrow (referring to the first part) can prevent mistakes when installing the prism assembly 3, wherein the first part, the second part, the third part and the first ink-coated portion 331 are all axially symmetrically arranged with the central axis of the prism assembly 3 parallel to its long direction. For example : The size difference of the first part, the second part and the third part in the width direction can be set between 0.2-0.6mm. The first part is close to the third side 325, and the third part is close to the fourth side 326. The width of the first ink-coated portion 331 between the first part and the third side 325 is 0.29±0.05mm and is relatively narrow, so as to ensure that light can be more easily projected onto the third side 325, thereby ensuring that the edges are blocked and stray light is reduced. Since the light is converged by the lens assembly 1 when entering from the incident surface 311, the range of the optical path is relatively small. Therefore, the distance between the two sides of the first part along the width and the first side 323 and the second side 324 is larger than the distance between the second and third parts and the first side 323 and the second side 324. Therefore, the ink-coated portion corresponding to the first ink-coated portion 331 is larger, thereby ensuring that light can enter while also absorbing more edge light through the ink coating; similarly, the ink-coated portions on both sides of the second part are wider than the ink-coated portions on both sides of the third part, because the refraction expansion range of the light is guaranteed as much as possible on the exit surface 312.At two corners corresponding to one side near the third side 325 in the first part, rounded corners are provided. Since the bottom surface 322 is basically not used for reflecting light, the second ink application part 332 is coated on the entire bottom surface 322. Similarly, since the first side surface 323 and the second side surface 324 are basically not used for reflecting light, the third ink application part 333 and the fourth ink application part 334 are respectively coated on the first side surface 323 and the second side surface 324. The fifth ink application part 335 is coated on the third side surface 325 along the four side edges of the third side surface 325 to form a square structure, and a first reflecting surface 313 is formed inside the fifth ink application part 335. Similarly, corresponding to the problem that the light rays of the incident surface 311 are converged, the intervals between the two sides of the first reflecting surface 313 in the width direction and the first side surface 323 and the second side surface 324 are relatively large, such as 1.88 ± 0.05 mm, and the size of the first reflecting surface 313 can be more than twice that, while the width of the fifth ink application part 335 between the first reflecting surface 313 and the top surface 321 and the bottom surface 322 is relatively narrow, such as 0.48 ± 0.05 mm. The sixth ink application part 336 is formed on the fourth side surface 326. Among them, ink is applied to both side edges of the fourth side surface 326 along the width, and ink is applied to the side edge of the fourth side surface 326 near the bottom surface 322 to form a U-shaped sixth ink application part 336. A third reflecting surface 315 is formed inside the sixth ink application part 336. Since the sixth ink application part 336 is close to the exit surface 312, the area of the sixth ink application part 336 on the two side edges of the third reflecting surface 315 in the width direction is narrower than the area of the fifth ink application part 335 on the two wide sides of the first reflecting surface 313, and there is no ink application between the side of the third reflecting surface 315 close to the top surface 321 and the top surface 321. However, in order to prevent light from being emitted from the connection between the third reflecting surface 315 and the top surface 321, an inclined plane is formed at this connection, and ink application treatment is performed on this inclined plane; correspondingly, an inclined plane can also be provided at the connection between the third side surface 325 and the top surface 321 and ink application treatment is performed. After the light rays are converged from the lens assembly 1 to the incident surface 311 and enter the prism assembly 3, the light rays will first be incident on the first reflecting surface 313, and the positions where the light rays corresponding to different angles from different positions on the lens assembly 1 are incident on the first reflecting surface 313 will also be different. The light passes through the first reflecting surface 313, the second reflecting surface 314, and the third reflecting surface 315 in sequence and is emitted from the exit surface 312. Among them, the light rays are focused on the incident surface 311 after being emitted from various directions to the lens assembly 1, and different light rays enter the prism assembly 3 after passing through the incident surface 311 and are reflected to form several different optical paths. Except for the part of the light rays absorbed by the ink application area 33, a part of the remaining normally reflected optical paths are emitted from the exit surface 312 after passing through the prism assembly 3 and are incident on the first side of the imaging assembly 6, and the optical path finally incident on the first side is configured as the first optical path. Figure 1It is represented by a yellow line. The remaining normal-reflected light path is reflected out of the exit surface 312 after passing through the prism assembly 3 and then shoots towards the second side of the imaging assembly 6. The light path that will ultimately shoot towards the second side is configured as the second light path. In Figure 1 It is represented by a blue line. In this embodiment, both the first light path and the second light path sequentially pass through the incident surface 311, the first reflection surface 313, the second reflection surface 314, the third reflection surface 315, and the exit surface 312. However, since the first light path is closer to the incident surface 311 than the second light path, and the second light path is closer to the exit surface 312. Therefore, when the first light path shoots from the first reflection surface 313 towards the second reflection surface 314, it is close to the incident surface 311. Thus, the light path of the first light path shooting from the second reflection surface 314 towards the third reflection surface 315 overlaps and intersects with the light path of the second light path shooting from the first reflection surface 313 towards the second reflection surface 314 to form an intersection area 34 (or crossing area). To ensure the final imaging consistency of the light in the intersection area 34, a stray light improvement area 36 is provided on the prism assembly 3. The stray light improvement area 36 is correspondingly arranged on the intersection area 34 to block and absorb light around the intersection area 34, so that the light avoids light deviation when passing through the stray light improvement area 36, enabling the corresponding first light path to shoot towards the third reflection surface 315 according to the established light path and ultimately shoot towards the first side of the imaging assembly 6, and enabling the corresponding second light path to shoot towards the second reflection surface 314 according to the established light path and ultimately shoot towards the second side of the imaging assembly 6, so that the brightness of the light received on both sides of the chip remains consistent, ensuring uniform brightness after imaging and ensuring imaging quality. In this embodiment, the external light corresponding to the first light path enters the prism assembly 3 from the incident surface 311 and then sequentially shoots towards the first reflection surface 313, the second reflection surface 314, the stray light improvement area 36, and the third reflection surface 315, and then shoots from the exit surface 312 towards the first side of the imaging assembly 6; the external light corresponding to the second light path enters the prism assembly 3 from the incident surface 311 and then sequentially shoots towards the first reflection surface 313, the stray light improvement area 36, the second reflection surface 314, and the third reflection surface 315, and then shoots from the exit surface 312 towards the second side of the imaging assembly 6.

[0042] It should be noted that on the prism assembly 3, the intersection area 34 has a lowest point 341 in the height direction of the prism assembly 3 (i.e., the extension direction of the shortest connection line between the top surface 321 and the bottom surface 322). The lowest point 341 is an intersection point on the intersection area 34 where the first light path and the second light path are closest to the bottom surface 322. The stray light improvement area 36 is arranged based on this lowest point 341.

[0043] In the content defined by the present invention, Pv of the first reflecting surface 313 and the third reflecting surface 315 is ≤ λ / 10, Pv of the top surface 321 is ≤ λ / 6, where λ is the wavelength and λ = 632.8 nm. The non-overplating area of the inking area 33 on the third side surface 325 and the fourth side surface 326 is ≥ 0.2 mm. It is required that the transmittance requirement AOI = 0° of the incident surface 311 between the first reflecting surfaces 313. Correspondingly, 400 - 700 nm Tavg ≥ 82%; 400 - 440 nm Tavg ≥ 78%; 441 - 670 nm Tavg ≥ 83%; 671 - 700 nm Tavg > 76% to ensure the light input quantity and increase the transmittance of visible light through inking and coating. Edge break requirements: The edge break depth (edge break surface diameter) of the non-inking area 33 < 0.05 mm, the edge break depth (edge break surface diameter) of the inking area 33 < 0.1 mm. Additionally, there are no more than 3 edge breaks with an edge break width > 0.15 mm, and the connection between each side surface needs to ensure no light leakage. The top surface 321, the bottom surface 322, the first side surface 323 to the fourth side surface 326 are inked, and long ink and overflow ink are not allowed. The overflow ink width < 0.08 mm, the internal reflectance (average value) ≤ 0.1% (400 - 700 nm), the transmittance (average value) ≤ 0.1% (400 - 650 nm); the internal reflectance (average value) of the inked bottom surface 322 ≤ 0.3% (400 - 700 nm); the ink reflectance (maximum value) of the top surface 321, the third side surface 325 and the fourth side surface 326 ≤ 0.5% (400 - 700 nm), and Ra ≤ 1 nm after coating to ensure light shielding, reduce the light reflectance and reduce the generation of stray light.

[0044] Embodiment 1

[0045] In this embodiment, the prism assembly 3 includes a first prism 351 in the shape of a right trapezoid and a second prism 352 in the shape of a right trapezoid. The side surfaces corresponding to the right angles of the first prism 351 and the second prism 352 are configured as right-angle surfaces. The first prism 351 and the second prism 352 are adhesively connected through the right-angle surfaces to form a trapezoidal prism assembly 3. Among them, the right-angle surfaces of the first prism 351 and the second prism 352 are arranged corresponding to the intersection area 34 of the prism assembly 3, and the stray light improvement area 36 is formed on the two right-angle surfaces of the adhesive connection and overlaps with the lowest point 341 of the intersection area 34. Among them, after corresponding silk printing is done on the right-angle surfaces, the first prism 351 and the second prism 352 are adhesively connected using an optical adhesive. The optical adhesive needs to ensure that the refractive index is consistent with the refractive index of the selected prism assembly 3 material, and the light transmittance needs to reach 99.7%. The light transmittance of the silk printing area 361 is less than 0.3%, and the reflectance is less than 0.5% to be able to absorb light sufficiently, and the adhesive gap is less than 2 mm.

[0046] In the content defined in this embodiment, the stray light improvement area 36 includes a silk-screen printing area 361 for blocking stray light and a light-transmitting area 362 for allowing light to pass through and complementary to the silk-screen printing area 361, so that the entire right-angle surface is covered by the silk-screen printing area 361 and the light-transmitting area 362. A continuous wavy boundary line 363 is formed between the silk-screen printing area 361 and the light-transmitting area 362. When light is incident on the position of the boundary line 363, the wavy structure of the boundary line 363 forms diffuse reflection on the light, improves the diffracted light, corrects part of the offset light, and the silk-screen printing area 361 blocks the stray light. Therefore, the sizes of the first prism 351 and the second prism 352 in the long direction are different, and the first prism 351 is relatively shorter than the second prism 352 to ensure that while the stray light improvement area 36 blocks the stray light, it reduces the impact on the imaging brightness and ensures the consistency of the picture brightness. The silk-screen printing area 361 has a U-shaped structure and includes a full-blocking section 3611 that blocks the bottom of the right-angle surface and semi-blocking sections 3612 that block both sides of the right-angle surface from both sides of the full-blocking section 3611 towards the top. The light-transmitting area 362 is located between the two semi-blocking sections 3612, and the boundary line 363 between the light-transmitting area 362 and the full-blocking section 3611 corresponds to the lowest point 341 of the intersection area 34, and the boundary line 363 between the light-transmitting area 362 and both sides of the full-blocking section 3611 corresponds to the edge of the intersection area 34. For example: the sizes of the right-angle surface are 8 ± 0.03 mm * 3.02 ± 0.03 (or ± 0.02) mm, the size between the boundary line 363 and the bottom surface 322 in the full-blocking section 3611 is 1.6 ± 0.05 mm, and the sizes on both sides of the light-transmitting area 362 to the first side surface 323 or to the second side surface 324, that is, the sizes of the semi-blocking sections 3612 are 1.58 ± 0.03 mm. The full-blocking section 3611 and the semi-blocking sections 3612 block the stray light, and the light is incident from the first reflecting surface 313 or the second reflecting surface 314, passes through the light-transmitting area 362, and then is incident on the second reflecting surface 314 or the third reflecting surface 315. Among them, the boundary line 363 is formed by alternately and staggeredly connecting a plurality of arcs with a radius of 0.05 mm. When light is incident on the boundary line 363, the boundary line 363 forms a plurality of micro-reflecting surfaces with random orientations, so that the reflection direction of the light is scattered at different angles, forming a spatially uniform reflection light path distribution, thereby forming a local angular perturbation, dispersing the light to a larger solid angle range, suppressing the reflection peak, forming diffuse reflection, and reducing the offset of light. Please refer to Figure 6 , B1 - B3 are the irradiance diagrams (simulation) corresponding to three optical paths selected in this embodiment. It can be seen that the glare, light spots, etc. are effectively improved. Corresponding to B2, its total energy is 9.26E - 04, the maximum irradiance is 8.38E - 04, the energy is significantly reduced, there is no ghost image, and the stray light is significantly improved. B4 - B5 are the irradiance diagrams with a straight boundary line 363, and their improvement effect is worse than that of the wavy line, and there are still a large amount of energy, stray light, and glare phenomena.

[0047] Embodiment 2

[0048] Please refer to Figures 7 to 12 , in this embodiment, the prism assembly 3 includes a third prism 353. The third prism 353 has a trapezoidal structure, and the third prism 353 can be an isosceles trapezoid. The stray light improvement region 36 includes a first light blocking groove 364 recessed in the bottom surface 322 and extending to the intersection region 34, second light blocking grooves 365 symmetrically recessed on both sides of the third prism 353 and offset from the first light blocking groove 364, and third and fourth light blocking grooves 366 and 367 formed on the bottom surface 322 and disposed on both sides of the first light blocking groove 364 along the optical path. Among them, the first light blocking groove 364, the second light blocking groove 365, the third light blocking groove 366, and the fourth light blocking groove 367 can all have a V-shaped structure or a U-shaped structure, or can have other shapes with a gradually narrowing or converging structure on one side. Therefore, the first light blocking groove 364 has a first converging side 3641 and converges from the bottom surface 322 toward the top surface 321, and the first converging side 3641 corresponds to the position of the lowest point 341 of the intersection region 34. Among them, the groove walls of the first light blocking groove 364, the second light blocking groove 365, the third light blocking groove 366, and the fourth light blocking groove 367 are all coated with ink to form a part of the ink-coated region 33.

[0049] A number of continuous first wave structures 368 for forming diffuse reflection of light are formed on the first converging side 3641. The first wave structures 368 have the same function as the boundary line 363 in Embodiment 1. The first wave structures 368 are directly formed by molding on the first converging side 3641 of the first light blocking groove, with a relatively small roughness and no scattering when light is incident on the first wave structures 368. Among them, the first wave structures 368 are composed of a number of regular arc surfaces 3681. The middle of the arc surface 3681 arches outward toward the bottom surface 322, while the two ends of the arc surface 3681 are recessed toward the top surface 321 and adjacent to other arc surfaces 3681, so that when light is incident on the first wave structures 368, multi-angle scattering is achieved, thereby correcting some of the offset light and effectively reducing the formation of stray light. Among them, the size of the arc surface 3681 is 0.47 mm and the radius is 0.2 ± 0.05 mm, and the radius of the recessed parts at both ends of the arc surface 3681 is 0.15 ± 0.05 mm. The groove depth of the first light blocking groove 364 is the same as the width of the full shielding section 3611 in Embodiment 1, for blocking the light outside the intersection region 34. Please refer to Figure 11 , where C1 - C2 are the optical path diagram distribution structures of the first wave structures 368. As can be seen from the figure, the light is diffusely reflected by the first wave structures 368, reducing the offset of the light. Please refer to Figure 12 , Figure 12 In C1 Figure 11 is the energy irradiance distribution of the light at the imaging component 6. Although there is still energy, the intensity of the energy is low, and the stray light phenomenon is improved. Figure 12In C2 is Figure 11 In C2 corresponds to the energy irradiance distribution, and its energy distribution is significantly reduced. As can be seen from the figure, after the light is incident from the incident surface 311 to the first reflection surface 313, the second reflection surface 314, and the first wavy structure 368, part of it continues to be incident on the second reflection surface 314 and the third reflection surface 315 and then exits from the exit surface 312. This part will generate partial stray light; part of the light is normally incident on the third reflection surface 315 after passing through the first wavy structure 368 and then exits from the exit surface 312. This part is the normal light path; there is also part of the light that is incident from the incident surface 311 on the first reflection surface 313, the second reflection surface 314, the light-transmitting region 362, and the third reflection surface 315 and then exits from the exit surface 312. This part is still the normal light path.

[0050] Please refer to Figure 11 and 12, the second light-blocking grooves 365 are respectively recessed from the first side surface 323 and the second side surface 324. The included angles between one side groove walls of the two second light-blocking grooves 365 and the corresponding first side surface 323 and second side surface 324 are 40°. And the two second light-blocking grooves 365 both have second converging sides 3651 and converge towards each other. The linear distance between the second converging side 3651 and the corresponding first side surface 323 and second side surface 324 is the same as the width of the semi-blocking section 3612 in the first embodiment. Thus, light-blocking regions are formed at the bottom and both sides of the third prism 353 to block the light outside the intersection region 34 on both sides and reduce the formation of stray light. Since the optical paths are different when light is reflected in the third prism 353, in order to further reduce the formation of stray light, a plurality of continuous second wave structures 369 for forming diffuse reflection of light are formed on the third light-blocking groove 366 and / or the fourth light-blocking groove 367. The formation and structure of the second wave structure 369 are the same as those of the first wave structure 368. The difference is that the third light-blocking groove 366 and the fourth light-blocking groove 367 are much smaller than the first light-blocking groove 364. The groove walls of the first light-blocking groove 364 are used for light-blocking, while the third light-blocking groove 366 and the fourth light-blocking groove 367 are used for reflecting some deflected light to reduce the formation of stray light. Among them, the third light-blocking groove 366 is closer to the third side surface 325, and the fourth light-blocking groove 367 is closer to the fourth side surface 326. The included angles between one side groove wall of the third light-blocking groove 366 close to the third side surface 325 and the groove wall far from the third side surface 325 and the bottom surface 322 are 10° and 45° respectively. The included angles between one side groove wall of the fourth light-blocking groove 367 close to the fourth side surface 326 and the side groove wall far from the fourth side surface 326 and the bottom surface 322 can both be 31°. The maximum distance between the third light-blocking groove 366 and the fourth light-blocking groove 367 is 4.484 mm. Among them, the second wave structure 369 is provided on the fourth light-blocking groove 367, and the second wave structure 369 may not be provided on the third light-blocking groove 366. In another embodiment, the second wave structure 369 can be provided on both the third light-blocking groove 366 and the fourth light-blocking groove 367, and both the third light-blocking groove 366 and the fourth light-blocking groove 367 have third converging sides 3671, and the second wave structure 369 is formed on the third converging side 3671. Figure 11 C3 in corresponds to the optical path distribution structure of the third light-blocking groove 366. C4 is the normal optical path, but stray light appears. Therefore, after the light is incident on the second reflecting surface 314 and the third reflecting surface 315, a small amount of it is reflected by the edge part to the second reflecting surface 314 and the third reflecting surface 315, and then reflected to the imaging assembly 6 to form stray light. Figure 12 C3 in corresponds to Figure 11 the energy irradiance distribution of C3 in Figure 12 C4 in corresponds to Figure 11The energy irradiance distribution of C4. It can be seen that there is no stray light on the imaging component 6 in the optical path reflected by the third light shielding groove 366, and the effect of the fourth light shielding groove 367 is similar; the stray light not processed by the stray light improvement area 36 has a higher energy intensity and has a greater impact on the image quality.

[0051] Please refer to Figures 13 to 17 , the camera module of the present invention includes a bracket 4, an anti-shake motor 5, a lens assembly 1, an imaging assembly 6, and a prism assembly 3. The bracket 4 has a mounting surface 41, and a mounting groove 42 is recessed on the mounting surface 41. The prism assembly 3 is installed in the mounting groove 42. The anti-shake motor 5 is disposed on one side of the mounting surface 41 and faces the incident surface 311, and the imaging assembly 6 is disposed on the other side of the mounting surface 41 and faces the exit surface 312. The lens assembly 1 is installed on the anti-shake motor 5. Among them, the bracket 4 supports the anti-shake motor 5, the prism assembly 3, and the imaging assembly 6. The anti-shake motor 5 is used for automatically focusing the lens assembly 1. The lens assembly 1, the imaging assembly 6, and the prism assembly 3 are all structures in the optical imaging system, which will not be elaborated here.

[0052] Inside the bracket 4, reinforcing ribs are integrally provided by injection molding. The reinforcing ribs are also the internal circuit installed inside the bracket 4 and can be used for electrical connection with the anti-shake motor 5 and the imaging component 6. Among them, the installation groove 42 is consistent with the outer contour of the prism component 3 so that the prism component 3 is adapted thereto. The anti-shake motor 5 can be a voice coil motor and is fixedly installed on the installation surface 41. Among them, in order to avoid the anti-shake motor 5 affecting the prism, the side of the anti-shake motor 5 close to the imaging component 6 is suspended above the top surface 321 of the prism component 3. The imaging component 6 includes an image sensor 61, a chip carrier 62, a filter 63, a circuit board 64, and a connector. Among them, the chip carrier 62 is installed on the installation surface 41 and surrounds the periphery of the exit surface 312. Similarly, the side of the chip carrier 62 close to the anti-shake motor 5 is suspended from the top surface 321 of the prism component 3 and is spaced apart therefrom. In order to ensure the stability between the anti-shake motor 5 and the chip carrier 62, a reinforcing block 2 is fixedly provided between the anti-shake motor 5 and the chip carrier 62. The reinforcing block 2 abuts against the outer wall of the anti-shake motor 5, and an adaptation groove 21 adapted to the side of the imaging component 6 is formed on the side surface of the reinforcing block 2 facing the imaging component 6. Both sides of the reinforcing block 2 are fixedly connected to the bracket 4, and the reinforcing block 2 is also suspended relative to the top surface 321 of the prism component 3, making it more stable through the abutment between the anti-shake motor 5 and the imaging component 6. During assembly, after the reinforcing block 2 is installed on the bracket 4, the anti-shake motor 5 and the imaging component 6 can be installed in sequence. When installing the imaging component 6, the imaging component 6 can be snapped into the adaptation groove 21 from the side of the adaptation groove 21 and then glued correspondingly. The filter 63 faces the exit surface 312 and is used to filter out unnecessary light. Then, the light passes through the filter 63 and irradiates onto the image sensor 61. Both the image sensor 61 and the connector are electrically connected to the circuit board 64. The circuit board 64 is fixed on the chip carrier 62. The image sensor 61 converts the optical signal into an electrical signal for the formation of a graphic. In order to prevent dust from entering the lens before the camera module is assembled, the camera module further includes a dust-proof cover 7, and the dust-proof cover 7 covers the anti-shake motor 5.

[0053] The electronic device of the present invention can be a device with a camera function such as a mobile phone or a tablet. The electronic device of the present invention includes the camera module of the present invention and also includes the optical imaging system in any one of the embodiments of the present invention.

[0054] The working mode of one embodiment of the optical imaging system, camera module and electronic device of the present invention is as follows: After removing the dust cover 7, the anti-shake motor 5 automatically focuses on the light. The light passes through the lens assembly 1 and then through the incident surface 311, the first reflection surface 313, the second reflection surface 314, and then through the light transmission area 362. A small amount of light is incident on the boundary line 363, and the offset light is diffusely reflected by the boundary line 363. Then the light is incident on the third reflection surface 315 and exits from the exit surface 312 to the filter 63. After being filtered by the filter 63, the light is incident on the image sensor 61 until the image sensor 61 processes the optical signal.

[0055] Compared with the prior art, the optical imaging system, camera module and electronic device of the present invention effectively reduce the light offset and the generation of stray light by setting the stray light improvement area 36 and making the light diffusely reflected from multiple angles by using the wavy structure.

Claims

1. An optical imaging system, comprising a lens assembly, an imaging assembly, and a prism assembly, characterized in that: The prism assembly has an incident surface and an exit surface on the same side. The lens assembly faces the incident surface, and the imaging assembly faces the exit surface. An ink-coated area and a stray light improvement area for improving stray light are formed on the prism assembly. Light travels from the lens assembly to the incident surface, is reflected multiple times within the prism assembly, passes through the stray light improvement area, and then is reflected to the exit surface.

2. The optical imaging system according to claim 1, characterized in that: Light enters the prism assembly from the incident surface in various directions and forms several different optical paths after reflection. The optical paths corresponding to both sides of the imaging assembly are respectively configured as a first optical path and a second optical path. The first optical path and the second optical path formed within the prism assembly overlap and intersect to form an intersection area, and the stray light improvement area is correspondingly arranged at the intersection area.

3. The optical imaging system according to claim 2, wherein: The prism assembly has a first reflecting surface, a second reflecting surface, and a third reflecting surface. The second reflecting surface is located between and on the same side as the incident surface and the exit surface. External light enters the prism assembly from the incident surface and then sequentially irradiates the first reflecting surface, the stray light improvement area, the second reflecting surface, and the third reflecting surface, and then exits from the exit surface; or external light enters the prism assembly from the incident surface and then sequentially irradiates the first reflecting surface, the second reflecting surface, the stray light improvement area, and the third reflecting surface, and then exits from the exit surface.

4. The optical imaging system according to claim 2 or 3, characterized in that: The prism assembly includes a first prism in the shape of a right trapezoid and a second prism in the shape of a right trapezoid. The right-angle surfaces corresponding to the right angles of the first prism and the second prism are adhesively connected to form the stray light improvement area. The stray light improvement area includes a silk-screen area for blocking stray light and a light-transmitting area for allowing light to pass through and complementary to the silk-screen area. A continuous wavy boundary line for forming diffuse reflection of light is formed between the silk-screen area and the light-transmitting area.

5. The optical imaging system according to claim 4, characterized in that: The silk-screen area has a U-shaped structure and includes a fully blocked section that blocks the bottom of the right-angle surface and semi-blocked sections that extend from both sides of the fully blocked section towards the top to block both sides of the right-angle surface. The light-transmitting area is located between the two semi-blocked sections, and the boundary line between the light-transmitting area and the fully blocked section corresponds to the lowest point of the intersection area.

6. The optical imaging system according to claim 4, characterized in that: The boundary line is formed by alternately and staggeredly connecting a number of arcs with a radius of 0.05 mm.

7. The optical imaging system according to claim 2 or 3, characterized in that: The prism assembly includes a third prism. The third prism has a bottom surface on the side facing away from the incident surface and the exit surface. The stray light improvement area includes a first light-blocking groove recessed in the bottom surface and extending to the intersection area, and second light-blocking grooves symmetrically recessed on both sides of the third prism and misaligned with the first light-blocking groove. The first light-blocking groove has a first converging side, and a number of continuous first wave structures for forming diffuse reflection of light are formed on the first converging side, and the first converging side corresponds to the lowest point of the intersection area; Both the first light-blocking groove and the second light-blocking groove are coated with a light-blocking material to form a light-blocking area at the bottom and both sides of the optical path.

8. The optical imaging system according to claim 7, characterized in that: The stray light improvement area further includes a third light-blocking groove and a fourth light-blocking groove formed on the bottom surface and distributed on both sides of the first light-blocking groove along the optical path. A number of continuous second wave structures for forming diffuse reflection of light are formed on the third light-blocking groove and / or the fourth light-blocking groove.

9. An imaging module, characterized in that: It includes a bracket, an anti-shake motor, a lens assembly, an imaging assembly and a prism assembly as described in any one of claims 1 to 8. The bracket has a mounting surface, and a mounting groove is recessed in the mounting surface. The prism assembly is mounted in the mounting groove. The anti-shake motor is disposed on one side of the mounting surface and faces the incident surface. The imaging assembly is disposed on the other side of the mounting surface and faces the exit surface. The lens assembly is mounted on the anti-shake motor.

10. An electronic device, characterized in that: It includes an optical imaging system as described in any one of claims 1 to 8.

Images