阅读说明：本技术 用于折叠透镜的折光棱镜 (Dioptric prism for folding lens ) 是由 重光学道 藤田和弥 田中秀树 黄硕玮 于 2019-08-30 设计创作，主要内容包括：本申请涉及用于折叠透镜的折光棱镜。本文公开了一种可用于折叠透镜系统中的光学折光棱镜,该光学折光棱镜由玻璃棱镜和玻璃透镜构成,玻璃透镜使用薄层的光学胶或通过光学接触件附接到棱镜的表面。玻璃透镜没有凸缘,并且因此该棱镜可小于具有相同透镜有效区域的常规折光棱镜中使用的棱镜,因此在与常规折光棱镜相比时,减小了折光棱镜的Z高度。光学玻璃可用于透镜,光学玻璃具有比由光学塑料提供的更高的折射率,这允许透镜比塑料透镜更薄。通过模制玻璃晶片以在晶片的第一表面上形成透镜形状来形成透镜,然后从第二表面研磨模制晶片以单切透镜。(The present application relates to a dioptric prism for a folded lens. Disclosed herein is an optical refractive prism usable in a folding lens system, which is composed of a glass prism and a glass lens attached to the surface of the prism using a thin layer of optical cement or through optical contacts. The glass lens has no flange, and thus the prism can be smaller than a prism used in a conventional prism having the same lens effective area, thereby reducing the Z height of the prism when compared to the conventional prism. Optical glass can be used for lenses, optical glass having a higher refractive index than that provided by optical plastic, which allows the lenses to be thinner than plastic lenses. The lens is formed by molding a glass wafer to form a lens shape on a first surface of the wafer, and then grinding the molded wafer from a second surface to singulate the lens.)

1. An optical refractive prism, comprising:

a prism including an object-side surface, a reflective surface, and an image-side surface; and

a glass lens attached to a surface of the prism;

wherein the width of the effective area of the glass lens is the same as the diameter of the glass lens.

2. The optical refractive prism of claim 1, wherein said glass lens is composed of a glass material having an Abbe number > 45.

3. The optical refractive prism of claim 1, wherein the prism is composed of an optical glass material having a higher refractive index than a glass material used in the glass lens.

4. The optical refractive prism of claim 1, wherein said glass lens is composed of an optical glass material having a refractive index > 1.5.

5. The optical refractive prism of claim 1, wherein the prism is constructed of an optical glass material having a refractive index >1.7 to provide total internal reflection at the reflective surface of the prism.

6. The optical refractive prism of claim 1, wherein the Z-axis height of the refractive prism is in the range of 3mm to 7 mm.

7. The optical refractive prism of claim 1, wherein the glass lens is attached to the surface of the prism using an optical glue or through an optical contact.

8. The optical refractive prism of claim 1, wherein the glass lens is attached to the object side surface of the prism.

9. The optical refractive prism of claim 1, wherein the glass lens is attached to the image side surface of the prism.

10. The optical refractive prism of claim 1, wherein the glass lens is attached to the object side surface of the prism, and wherein a second glass lens is attached to the image side surface of the prism.

11. The optical refractive prism of claim 1, wherein said glass lens is a plano-convex lens.

12. The optical refractive prism of claim 1, wherein said glass lens is a plano-concave lens.

13. The optical refractive prism of claim 1, wherein said glass lens is a plano-convex lens, wherein said glass lens is attached to said object side surface of said prism, and wherein an aperture stop is located at an outer edge of said glass lens.

14. A lens system, the lens system comprising:

a plurality of elements arranged along a folded optical axis of the lens system, wherein the plurality of elements comprises, in order along the folded optical axis from an object side of the lens system to an image side of the lens system:

a refractive prism that redirects light received from an object field from a first portion of the folded optical axis to a second portion of the folded optical axis, wherein the refractive prism comprises:

a glass prism including an object-side surface, a reflective surface, and an image-side surface; and is

A glass lens attached to the object-side surface of the prism, wherein a width of an active area of the glass lens is the same as a diameter of the glass lens; and is

A lens stack comprising one or more refractive lens elements that refract light on the second portion of the folded optical axis to form an image at an image plane.

15. The lens system of claim 14, further comprising a prism on the image side of the lens stack that redirects light received from the lens stack from the second portion of the folded optical axis to a third portion of the folded optical axis.

16. The lens system of claim 14, wherein the glass lens is a plano-convex lens.

17. The lens system of claim 14, further comprising an aperture stop located at an outer edge of the glass lens.

18. The lens system of claim 14, wherein the glass lens is comprised of an optical glass material having a refractive index >1.5, and wherein the prism is comprised of an optical glass material having a refractive index >1.7 to provide total internal reflection at the reflective surface of the prism.

19. A camera, the camera comprising:

an image sensor configured to capture light projected onto a surface of the image sensor;

a refractive prism that redirects light received from an object field from a first portion of an optical axis to a second portion of the optical axis, wherein the refractive prism comprises:

a glass prism including an object-side surface, a reflective surface, and an image-side surface; and is

A glass lens attached to the object-side surface of the prism, wherein a width of an active area of the glass lens is the same as a diameter of the glass lens; and is

One or more refractive lens elements that refract light on the second portion of the optical axis to form an image at an image plane at or near a surface of the image sensor.

20. The camera of claim 19, further comprising a prism between the one or more refractive lens elements and the image sensor, the prism redirecting light received from the one or more refractive lens elements from the second portion of the folded optical axis to a third portion of the folded optical axis.

Technical Field

The present disclosure relates generally to camera systems and, more particularly, to a refractive prism for a folded lens system.

Background

The advent of small multi-purpose mobile devices such as smart phones and tablets or tablet devices has resulted in a need for high resolution small profile cameras that are lightweight, compact and capable of capturing high resolution high quality images with low f-number for integration into the devices. However, due to limitations of conventional camera technology, conventional miniature cameras used in such devices tend to capture images at lower resolutions and/or lower image qualities than can be achieved with larger, higher quality cameras. Achieving higher resolution using small package size cameras typically requires the use of image sensors with small pixel sizes and good compact imaging lens systems. Technological advances have enabled a reduction in the pixel size of image sensors. However, as image sensors become more compact and powerful, the demand for compact imaging lens systems with improved imaging quality performance has increased. Furthermore, there is an increasing desire for small profile cameras to be equipped with higher pixel counts and/or larger pixel size image sensors (one or both of which may require larger image sensors) while still maintaining a module height that is compact enough to fit into a portable electronic device. Accordingly, a challenge from the design of optical systems is to provide an imaging lens system that is capable of capturing high brightness high resolution images under the physical constraints imposed by small outline cameras.

Disclosure of Invention

Embodiments of optical prisms having refractive power that can be used in folding lens systems are described herein, for example, for small-profile cameras in multipurpose mobile devices such as smart phones and tablets or tablet devices. The folded lens system may include one or more prisms and a lens stack including one or more refractive lens elements. The first prism redirects light from the first optical axis to the second optical axis, thereby providing a "folded" optical axis for the lens system. Folding the optical axis using a prism may, for example, reduce the Z-height of the lens system, and thus may reduce the Z-height of a camera including the lens system. In some folded lens systems, a second prism may be located on the image side of the lens stack to fold the optical axis onto a third axis.

In some folding lens systems, a prism having a refractive power (referred to as a dioptric prism) may be used. For example, in some camera designs, a folded lens system may require a lens on the object side of the first prism. Instead of using a separate lens on the object side of the prism, a dioptric prism consisting of a prism and a lens deposited on or attached to the object side surface of the prism may be used. One advantage of the dioptric prism is that the convex object side surface of the lens can be positioned closer to the surface of the prism than if a separate lens were used, thus reducing the Z-height of the folded lens system.

Conventionally, a dioptric prism for a folded lens system is formed using a replication process in which a plastic material is deposited on the surface of the prism, formed into a lens shape, and cured using ultraviolet light, or alternatively using the following process: a process of forming a plastic lens and attaching it to a surface of a prism using an injection molding process. However, these conventional processes result in a flange being formed around the plastic lens, which requires that the surface of the prism be large enough to accommodate the flange. The size of the surface of the prism to which the lens is attached determines the size of the prism. As the size of the surface of the prism to which the plastic lens with the flange is attached increases, the Z height of the prism, and thus the refractive prism including the lens, increases.

Embodiments of refractive prisms useful in folded lens systems are described herein. The dioptric prism consists of a glass prism and a glass lens attached to the surface of the prism using an optical glue or through optical contacts. The glass lens has no flange. Since the glass lens has no flange, the size of the prism to which the glass lens is attached may be smaller than the size of the prism to which the plastic lens having a flange is attached. As the size of the surface of the prism to which the glass lens is attached is reduced, the Z height of the prism, and thus of the refractive prism including the lens, is reduced. Accordingly, embodiments of the refractive prism described herein may provide a reduced Z height when compared to refractive prisms formed using conventional methods.

In addition, eliminating the flange allows the glass lens to be thinner than a plastic lens formed by conventional methods. In addition, a glass material having a higher refractive index than that provided by a plastic material used in a conventional method may be used for the lens of the dioptric prism. The higher refractive index allows the glass lens to be thinner than a plastic lens formed by a conventional method. Accordingly, in addition to reducing the Z height of the prism by reducing the Z height of the prism, embodiments of the refractive prism described herein may also reduce the Z height by reducing the thickness of the lens.

An embodiment of a method of manufacturing a refractive prism is described, in which a glass lens is formed by a process in which a glass wafer is molded to form a lens shape on a first surface of the wafer, and then the molded wafer is ground from a second surface to singulate or separate the glass lens. The glass lens thus formed had no flange. A single cut glass lens is then attached to the surface of the glass prism using a thin layer of optical glue or through optical contacts to form a refractive prism. In embodiments where the lens is attached to the prism using optical glue, the thickness of the glue, and thus the spacing between the planar surface of the lens and the surface of the prism, may be <10 microns. In embodiments where the lens is attached to the prism using optical contacts, the separation between the planar surface of the lens and the surface of the prism may be <5 microns.

Drawings

Fig. 1 illustrates a camera having a folded lens system according to some embodiments.

Fig. 2 illustrates a conventional prism formed by a process of depositing a plastic lens on the surface of a prism.

Fig. 3 illustrates a refractive prism formed by attaching a single-cut glass lens to the surface of the prism, according to some embodiments.

Fig. 4A to 4D compare a prism such as that shown in fig. 3 with that shown in fig. 2, according to some embodiments.

Fig. 5A to 5G illustrate a method of manufacturing the prism for refraction illustrated in fig. 3 according to some embodiments.

Fig. 6A to 6F show various alternative embodiments of the prism for refraction as shown in fig. 3.

Fig. 7A to 7D illustrate various embodiments of a camera having a folded lens system including at least one refractive prism.

Fig. 8 is a flow diagram of a method of capturing an image using an embodiment of a folded lens system including a refractive prism, according to some embodiments.

Fig. 9 is a flow chart of a method of manufacturing a refractive prism as shown in fig. 3, according to some embodiments.

FIG. 10 illustrates an exemplary computer system.

This specification includes references to "one embodiment" or "an embodiment". The appearances of the phrase "in one embodiment" or "in an embodiment" are not necessarily referring to the same embodiment. The particular features, structures, or characteristics may be combined in any suitable manner consistent with the present disclosure.

"include". The term is open ended. As used in the appended claims, the term does not exclude additional structures or steps. Consider the claims referring to: "an apparatus comprising one or more processor units," such claims do not exclude that the apparatus comprises additional components (e.g., network interface units, graphics circuitry, etc.).

"configured to". Various units, circuits, or other components may be described or recited as being "configured to" perform a task or tasks. In such context, "configured to" is used to connote structure by indicating that the units/circuits/components include structure (e.g., circuitry) that performs such task or tasks during operation. As such, the unit/circuit/component may be configured to perform this task even when the specified unit/circuit/component is not currently operational (e.g., not turned on). The units/circuits/components used with the "configured to" language include hardware, e.g., circuitry, memory storing program instructions executable to perform operations, and so on. References to a unit/circuit/component "being configured to" perform one or more tasks is expressly intended to not refer to 35u.s.c. § 112(f) for that unit/circuit/component. Further, "configured to" may include a general-purpose structure (e.g., a general-purpose circuit) that is manipulated by software and/or firmware (e.g., an FPGA or a general-purpose processor executing software) to operate in a manner that is capable of performing one or more tasks to be solved. "configured to" may also include adjusting a manufacturing process (e.g., a semiconductor fabrication facility) to manufacture a device (e.g., an integrated circuit) suitable for performing or carrying out one or more tasks.

"first", "second", etc. As used herein, these terms serve as labels to the nouns preceding them, and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.). For example, the buffer circuit may be described herein as performing a write operation of a "first" value and a "second" value. The terms "first" and "second" do not necessarily imply that the first value must be written before the second value.

"based on". As used herein, the term is used to describe one or more factors that affect the determination. The term does not exclude additional factors that influence the determination. That is, the determination may be based solely on these factors or at least partially on these factors. Consider the phrase "determine a based on B. In this case, B is a factor that affects the determination of a, and such phrases do not exclude that the determination of a may also be based on C. In other examples, a may be determined based on B alone.

Detailed Description

Embodiments of optical prisms having refractive power that can be used in folding lens systems are described herein, for example, for small-profile cameras in multipurpose mobile devices such as smart phones and tablets or tablet devices. The folded lens system may include one or more prisms and a lens stack including one or more refractive lens elements. The first prism redirects light from the first optical axis to the second optical axis, thereby providing a "folded" optical axis for the lens system. Folding the optical axis using a prism may, for example, reduce the Z-height of the lens system, and thus may reduce the Z-height of a camera including the lens system. In some embodiments, a second prism may be located on the image side of the lens stack to fold the optical axis onto the third axis.

In some folding lens systems, a prism having a refractive power (referred to as a dioptric prism) may be used. For example, in some camera designs, a folded lens system may require a lens on the object side of the first prism. Instead of using a separate lens on the object side of the prism, a dioptric prism consisting of a prism and a lens deposited on or attached to the object side surface of the prism may be used. One advantage of the dioptric prism is that the convex object side surface of the lens can be positioned closer to the surface of the prism than if a separate lens were used, thus reducing the Z-height of the folded lens system.

Conventionally, a dioptric prism for a folded lens system is formed using a replication process in which a plastic material is deposited on the surface of the prism, formed into a lens shape, and cured using ultraviolet light, or alternatively using the following process: a process of forming a plastic lens and attaching it to a surface of a prism using an injection molding process. However, these conventional processes result in a flange being formed around the plastic lens, which requires that the surface of the prism be large enough to accommodate the flange. The size of the surface of the prism to which the lens is attached determines the size of the prism. As the size of the surface of the prism to which the plastic lens with the flange is attached increases, the Z height of the prism, and thus the refractive prism including the lens, increases. One goal of a low profile camera is to reduce the Z-height of the camera for use in thin multi-purpose mobile devices. The limiting factor of the Z height in conventional folded lens systems is the Z height of these conventional refractive prisms.

Optical prisms having refractive power (referred to herein as refractive prisms) that can be used in a folded lens system are described herein. The prism consists of a glass prism and a glass lens attached to the surface of the prism. In some embodiments, instead of using a replication process or an injection molding process to form a plastic lens for a refractive prism, a process is used in which a glass wafer is molded to form a lens shape on a first surface of the wafer, and then the molded wafer is ground from a second surface to singulate or separate the glass lens. The glass lens thus formed had no flange. The singulated glass lenses are then attached to the surface of the glass prisms using a thin layer (<10 microns) of optical glue or through optical contacts. Since the glass lens has no flange, the surface of the prism to which the glass lens is attached may be smaller than the prism used in the above conventional prism, and the prism formed by attaching the glass lens to the prism may be smaller than the above conventional prism. As the size of the surface of the prism to which the glass lens is attached is reduced, the Z height of the prism, and thus of the refractive prism including the lens, is reduced.

In addition to reducing the size of the prism by eliminating the increased width of the flange, eliminating the thickness of the flange also allows the glass lens to be thinner than a plastic lens formed by conventional methods. In addition, glass materials having a higher refractive index than that provided by the plastic materials used to form the lenses in conventional methods can be used for the lenses. The higher refractive index allows the glass lens to be thinner than a plastic lens formed by a conventional method.

The prism and the lens may be formed of optical glass. In some embodiments, the prism and the lens may be composed of the same glass material. However, in some embodiments, the prisms and lenses may be composed of different glass materials. In some embodiments, the lens may be constructed of a glass material with an abbe number >45 to correct chromatic aberration. In some embodiments, the prism may be composed of a glass material having a higher refractive index than the glass material used in the lens. In some embodiments, the lens may be composed of a glass material with a refractive index > 1.5. In some embodiments, the prism may be constructed of a glass material with a refractive index >1.7 to provide total internal reflection at the angled reflective surface of the prism.

While embodiments of a dioptric prism in which a glass lens is attached to the object side of the prism are described, in some embodiments, a glass lens may alternatively or also be attached to the image side of the prism to form a dioptric prism for use in a folded lens system. Further, although embodiments of plano-convex glass lenses attached to prisms are described, plano-concave lenses or other types of lenses with flat surfaces may also be attached to prisms. Note that the flat surface of the lens is attached to the flat surface of the prism.

Fig. 1 illustrates a camera including a folded lens system with a refractive prism, according to some embodiments. Fig. 1 shows the components of a camera 100 that includes a folded lens system having two prisms 120 and 140, one or more refractive lenses 132 (in this example, three lenses 132A, 132B, and 132C), the one or more refractive lenses 132 being located in a lens barrel 130 between the prisms 120 and 140. Prisms 120 and 140 provide a "folded" optical axis for camera 100. The reflective surface 122 of the first prism 120 redirects light from the object field from a first axis (AX1) to a lens 132 on a second axis (AX 2). The lens 132 refracts the light to a reflective surface 142 of a second prism 140, which redirects the light onto a third axis (AX3) on which the image sensor 160 of the camera 100 is disposed. The redirected light forms an image at an image plane at or near the surface of the image sensor 160. The camera 100 may, but need not, include an Infrared (IR) filter 150, for example, between the second prism 140 and the image sensor 160. The camera 100 may further include an aperture stop 150, e.g., on the object side of the first prism 120. The number, shape, material, and arrangement of the refractive lens elements 132 in the lens barrel 130 may be selected according to the requirements of a particular camera 100.

As shown in the exemplary camera 100 of fig. 1, in some folded lens systems, a prism having a refractive power (referred to as a dioptric prism 190) may be used. In this example, to form the dioptric prism 190, the lens 110 is deposited on the object side of the prism 120 using a replication process, in which a plastic material is deposited on the surface of the prism 120, formed into a lens shape, and cured using ultraviolet light. Alternatively, to form the prism 190, the plastic lens 110 may be formed and attached to the surface of the prism 120 using an injection molding process. However, these processes result in the formation of the flange 114 around the plastic lens 110, which requires that the surface of the prism 120 be large enough to accommodate the flange 114. The size of the surface of the prism 120 to which the lens 110 is attached determines the size of the prism 120. As the size of the surface of the prism 120 to which the lens 110 is attached increases, the Z height of the prism 120, and thus the refractive prism 190 including the lens 110, increases. One goal of a low profile camera is to reduce the Z-height of the camera for use in thin multi-purpose mobile devices. The limiting factor of the Z height in conventional folded lens systems is the Z height of these conventional refractive prisms 190.

Fig. 2 shows a conventional dioptric prism 190 formed by a replication process that deposits a plastic lens 110 (referred to as a plastic lens) on the surface of the prism 120, or alternatively uses the following process: the plastic lens 110 is formed and attached to the surface of the prism 120 using an injection molding process. Fig. 2 shows a side view (a) and a top view (B) of the dioptric prism 190. As can be seen in fig. 2, this process forms a flange 114 around the active area 112 of the plastic lens 110. The effective area of the lens may be defined by the effective diameter of the lens. In the optical device, the effective area of the lens may be defined as twice the distance from the geometric center of the lens to the edge of the lens shape (in this example, a plano-convex lens shape). In an optical system comprising a through-hole and a sensor, the through-hole and the focal length of the optical system determine the cone angle of the beam forming the focal spot at the image plane at or near the sensor. The active area of the lens in the optical system is or comprises the lens area in which the ray bundle defined by the through-opening is influenced by the lens. A flange 114 extends outwardly from the edge of the lens 110 shape. In addition, a rim 116 may be required around the flange 114 to accommodate slight variations in the manufacturing process. The overall diameter of the lens 110 is the width 118 at the flange 114 (e.g., the effective diameter of the lens 110 plus twice the width of the flange 114). The width 118 of the lens 110 at the flange 114 requires that the surface of the prism 120 to which the lens 110 is attached be large enough to accommodate the flange 114 plus the edge 116. The size of the surface of the prism 120 to which the lens 110 is attached determines the size of the prism 120. As the size of the surface of the prism 120 to which the plastic lens 110 is attached increases, the Z height of the prism 120 and thus the refractive prism 190 increases. By way of non-limiting example, the prism 120 may have a Z-axis height of about 4mm, and the plastic lens 110 may have a total thickness (including the thickness of the flange 114, e.g., 0.1mm) of about 0.6mm, while the total Z-axis height of the dioptric prism 190 is 4.6 mm.

Fig. 3 shows a refractive prism 390 formed by attaching a single-cut glass lens 370 to the surface of a prism 380, according to some embodiments. Fig. 3 shows a side view (a) and a top view (B) of the dioptric prism 390. As can be seen in fig. 3, the glass lens 370 is formed by a process that does not form a flange around the active area 312 of the lens 370. An exemplary method for forming the glass lens 370 is illustrated in fig. 5A to 5D and fig. 9. The glass lens 370 may be attached to the prism 380 using a thin layer (<10 microns) of optical glue or through optical contacts, as shown in fig. 5E-5G and 9. An edge 316 may be required around the lens 370 to accommodate slight variations in the manufacturing process. Since the lens 370 has no flange, the diameter of the lens 370 is the width of the active area 312 of the lens 370 (e.g., the lens effective diameter). By eliminating the flange, the surface of the prism 380 to which the glass lens 370 is attached can be smaller than the surface of the prism 120, with the plastic lens 110 having the same active area as the glass lens 370 deposited on the surface of the prism 120 using the process shown in fig. 2. The size of the surface of the prism 120 on which the lens 110 is deposited determines the size of the prism 120. Since the size of the surface of the prism 380 to which the glass lens 370 is attached is reduced, the Z height of the prism 380, and thus the Z height of the dioptric prism 390, is reduced when compared with the dioptric prism 190 of fig. 2.

In addition to reducing the Z-height of the prism 380 by eliminating the increased width of the flange, eliminating the thickness of the flange may also allow the glass lens 370 to be thinner than the plastic lens 110 formed by conventional methods. In addition, a glass material having a higher index of refraction than that provided by the plastic material used to form the lens 110 may be used for the lens 370. The higher refractive index allows the glass lens 370 to be thinner than the plastic lens 110 formed by the conventional method.

The prism 380 and the lens 370 may be formed of optical glass. In some embodiments, the prism 380 and the lens 370 may be composed of the same glass material. However, in some embodiments, the prism 380 and the lens 370 may be constructed of different glass materials. In some embodiments, the lens 370 may be constructed of a glass material with an abbe number >45 to correct chromatic aberration. In some embodiments, the prism 380 may be constructed of a glass material having a higher index of refraction than the glass material used in the lens 370. In some embodiments, the lens 370 may be composed of a glass material with a refractive index > 1.5. In some embodiments, the prism 380 may be constructed of a glass material with a refractive index >1.7 to provide total internal reflection at the tilted reflective surfaces of the prism.

Fig. 4A-4D compare a refractive prism 390 as shown in fig. 3 with a refractive prism 190 as shown in fig. 2, according to some embodiments.

Fig. 4A shows a side view of the prism 190 and the prism 390. As can be seen in fig. 4A, the elimination of the flange 114 allows the use of a smaller prism 380 in the dioptric prism 390 than the prism 120 used in the dioptric prism 190. In addition, as can be seen in fig. 4A, eliminating the thickness of the flange 114 allows the glass lens 370 to be thinner than the plastic lens 110 formed by conventional methods. In addition, a glass material having a higher refractive index than that provided by the plastic material used to form the lens 110 may be used for the lens 370, which allows the glass lens 370 to be thinner than the plastic lens 110 formed by conventional methods. Fig. 4A shows a reduction in the Z height of the prism 390 when compared with the prism 190 due to the elimination of the width of the flange 114, and also shows a reduction in the Z height of the prism 390 when compared with the prism 190 due to the elimination of the thickness of the flange 114 in combination with the higher refractive index of the glass material used in the glass lens 370.

By way of non-limiting example, the prism 120 may have a Z-axis height of about 4mm, and the plastic lens 110 may have a total thickness (including the thickness of the flange 114) of about 0.6mm, while the total Z-axis height of the dioptric prism 190 is 4.6 mm. The overall width of the flange 114 may be about 0.45 millimeters (mm) (0.225 mm on each side of the active area), and the thickness of the flange 114 may be about 0.1 mm. Eliminating the width of the flange 114 allows the Z-axis height of the prism 380 (and thus the Z-axis height of the refractive prism 390) to be reduced by about 0.45 mm. Thus, the Z-axis height of the prism 380 may be about 3.55 mm. Eliminating the thickness of the flange 114 allows the thickness of the lens 370 (and hence the Z-axis height of the refractive prism 390) to be reduced by 0.1 mm. The higher refractive index of the glass material used in the glass lens 370 may allow the thickness of the lens 370 (and thus the Z-axis height of the refractive prism 390) to be reduced by an additional 0.03 mm. Thus, the total reduction in the Z-axis is about 0.58 mm. Accordingly, the Z-axis height of the dioptric prism 390 may be about 4.0 mm. It is noted, however, that refractive prisms 390 having greater or lesser Z-axis heights (e.g., in the range of 3mm to 7 mm) may be provided.

Fig. 4B shows a side view of the prism 190 and the prism 390. As can be seen in fig. 4B, the elimination of the flange 114 allows the use of a smaller prism 380 in the dioptric prism 390 than the prism 120 used in the dioptric prism 190. In addition to reducing the Z-height of the prism 390, eliminating the flange 114 also allows the prism 380 to be reduced in other (X-axis and Y-axis) dimensions.

Fig. 4C and 4D show top views of the prism refraction 190 and the prism refraction 390. As can be seen in fig. 4C, eliminating the flange 114 allows the surface of the prism 380 to which the glass lens 370 is attached to be smaller than the surface of the prism 120 on which the plastic lens 110 is deposited, while providing an active area 312 in the glass lens 370 that is the same size as the active area 112 of the plastic lens 110. As can be seen in fig. 4D, the elimination of the flange 114 reduces the required extended width of the prism 380. For prism 120, the width of the extension on one side is equal to the width of the flange plus the width of the edge. Total extension width plus 2 (flange width + edge width). The overall extended width of the prism 120 is >0.5mm, taking into account a flange width of 0.225mm and an edge width of 0.05 mm. For the prism 380, the total extension width is 2 x the edge width. The total extended width of the prisms 380 is 0.1mm, or overall <0.2mm, taking into account an edge width of 0.05 mm. Eliminating the flange 114 also allows the prism 380 to be reduced in the X, Y, and Z dimensions. Since the size of the prism 380 to which the glass lens 370 is attached is reduced, the Z height of the prism 390 is reduced when compared with the prism 190.

Fig. 5A to 5G illustrate a method of manufacturing the prism for refraction illustrated in fig. 3 according to some embodiments. In this method, a glass lens is formed by a process in which a glass wafer is molded to form a lens shape on a first surface of the wafer, and then the molded wafer is ground from a second surface to singulate or separate the glass lens. The glass lens thus formed had no flange. A single cut glass lens is then attached to the surface of the glass prism using a thin layer of optical glue or through optical contacts to form a refractive prism. In embodiments where the lens is attached to the prism using optical glue, the thickness of the glue, and thus the spacing between the planar surface of the lens and the surface of the prism, may be <10 microns. In embodiments where the lens is attached to the prism using optical contacts, the separation between the planar surface of the lens and the surface of the prism may be <5 microns.

In fig. 5A, an optical glass wafer 510A is positioned between a top mold 500A and a bottom mold 500B. In fig. 5B, wafer 510A is pressed between molds 500A and 500B to form a molded glass wafer 510B having the desired lens shape on the first surface of wafer 510B, as shown in fig. 5C. In fig. 5D, the molded wafer 510B is positioned in a precision grinding and polishing mechanism 520 in which the wafer is ground and polished from the second surface to singulate or separate the plano-convex glass lens 570, as shown in fig. 5E. In fig. 5F, a single-cut plano-convex glass lens 570 is attached to the surface of a glass prism 580 using a thin layer (<10 microns) of optical glue or through optical contacts to form a refractive prism 590, as shown in fig. 5G. In some embodiments, an anti-reflective coating may be applied to at least one surface of the glass lens before the single cut by grinding, or alternatively after the single cut.

The prism 580 and the lens 570 may be formed of optical glass. In some embodiments, prism 580 and lens 570 may be composed of the same glass material. However, in some embodiments, prism 580 and lens 570 may be composed of different glass materials. In some embodiments, the lens 570 may be constructed of a glass material with an abbe number >45 to correct chromatic aberration. In some embodiments, prism 580 may be composed of a glass material having a higher index of refraction than the glass material used in the lens. In some embodiments, the lens 570 may be composed of a glass material with a refractive index > 1.5. In some embodiments, prism 580 may be constructed of a glass material with a refractive index >1.7 to provide total internal reflection at the tilted reflective surfaces of the prism.

Fig. 6A to 6F show various alternative embodiments of the prism for refraction as shown in fig. 3. While embodiments of a dioptric prism in which a glass lens is attached to the object side of the prism are generally described, in some embodiments, a glass lens may alternatively or also be attached to the image side of the prism to form a dioptric prism for use in a folded lens system. Further, although an embodiment of a plano-convex glass lens having a positive refractive power attached to a prism is described, a plano-concave lens or other type of lens may be attached to the prism.

Fig. 6A shows a dioptric prism 690A composed of a plano-convex glass lens having positive refractive power attached to the object side of the prism. As shown in fig. 6A, in some embodiments, the aperture stop may be located at the outer edge of the lens. Fig. 6B shows a dioptric prism 690B composed of a plano-convex glass lens having a positive refractive power attached to the image side of the prism. Fig. 6C shows a dioptric prism 690C composed of a concave glass lens having a negative refractive power attached to the object side of the prism. Fig. 6D shows a dioptric prism 690D composed of a concave glass lens having a negative refractive power attached to the image side of the prism. Fig. 6E shows a dioptric prism 690E composed of a plano-convex glass lens having positive refractive power attached to the object side of the prism and a plano-convex glass lens having positive refractive power attached to the image side of the prism. Fig. 6F shows a dioptric prism 690F composed of a plano-convex glass lens having positive refractive power attached to the object side of the prism and a concave glass lens having negative refractive power attached to the image side of the prism.

Fig. 7A to 7D illustrate various embodiments of a camera having a folded lens system including at least one dioptric prism illustrated in fig. 6A to 6F. Fig. 7A shows a camera 700A that includes, from an object side to an image side, a refractive prism 790, a lens barrel 730 containing one or more refractive lens elements, a standard prism 740, and an image sensor 760. Fig. 7B shows a camera 700B including, from an object side to an image side, a refractive prism 790, a lens barrel 730 including one or more refractive lens elements, and an image sensor 760. Fig. 7C shows a camera 700C that includes, from the object side to the image side, a standard prism 740, a lens barrel 730 containing one or more refractive lens elements, a dioptric prism 790, and an image sensor 760. Fig. 7D shows a camera 700D including, from the object side to the image side, a first refraction prism 790A, a lens barrel 730 including one or more refractive lens elements, a second refraction prism 790B, and an image sensor 760.

Fig. 8 is a flow diagram of an exemplary method of capturing an image using an embodiment of a folded lens system including a refractive prism as shown in fig. 3-7, according to some embodiments. As shown at 2000, light from the object field is received through an aperture stop on a first axis of an object side surface of the prism. In some embodiments, the dioptric prism may include a glass lens (e.g., a plano-convex lens with positive refractive power) attached to the object side of the prism. As shown in fig. 6A, in some embodiments, the aperture stop may be located at the outer edge of the glass lens. As shown at 2010, light received on the object side of the dioptric prism is redirected by the prism through the image side of the prism to a lens stack comprising one or more refractive lens elements located on a second axis. In some embodiments, the refractive prism may include a glass lens (e.g., a concave lens having a negative refractive power) attached to the image side of the prism. As shown at 2020, light received from the refractive prism is then refracted by one or more lens elements in the lens stack to the second prism. In some embodiments, the second prism may also be a refractive prism comprising a glass lens attached to at least one surface of the prism. As shown at 2030, the second prism redirects the light to form an image at an image plane at or near the surface of the image sensor or sensor module on the third axis. The image sensor or sensor module may then capture an image.

In some embodiments, the second prism may not be present, for example as shown in fig. 7B. In these embodiments, the lens stack refracts light to form an image at or near the surface of the image sensor or sensor module in the second axis.

In some embodiments, the light may pass through an infrared filter, which may be located, for example, between the lens stack and the image sensor.

Fig. 9 is a flow chart of a method of manufacturing a refractive prism as shown in fig. 3, according to some embodiments. As shown at 2100, an optical glass wafer is molded to form a plurality of lens shapes on a first surface of the wafer, for example as shown in fig. 5A-5C. The molded glass wafer is ground and polished from the second surface as shown at 2110 to produce a rimless singulated glass lens, for example as shown in fig. 5D and 5E. As shown at 2120, a single-cut lens is attached to the surface of the glass prism using optical glue or optical contacts to create a refractive prism, for example as shown in fig. 5F and 5G.

Exemplary computing device

Fig. 10 illustrates an exemplary computing device, referred to as a computer system 2000, which may include or host an embodiment of a camera having a folded lens system including at least one refractive prism as shown in fig. 3-9. Further, the computer system 2000 may implement methods for controlling the operation of the camera and/or for performing image processing on images captured with the camera. In different embodiments, the computer system 2000 may be any of various types of devices, including but not limited to: personal computer systems, desktop computers, laptop computers, notebook computers, tablet or tablet devices, all-in-one or netbook computers, mainframe computer systems, handheld computers, workstations, network computers, cameras, set-top boxes, mobile devices, wireless telephones, smart phones, consumer devices, video game controllers, handheld video game devices, application servers, storage devices, televisions, video recording devices, peripheral devices such as switches, modems, routers, or generally any type of computing or electronic device.

In the illustrated embodiment, the computer system 2000 includes one or more processors 2010 coupled to a system memory 2020 via an input/output (I/O) interface 2030. The computer system 2000 also includes a network interface 2040 coupled to the I/O interface 2030, and one or more input/output devices 2050, such as a cursor control device 2060, a keyboard 2070 and one or more displays 2080. The computer system 2000 may also include one or more cameras 2090, for example including at least one camera having a folded lens system with a refractive prism as described above with respect to fig. 3-9.

In various embodiments, the computer system 2000 may be a single-processor system including one processor 2010, or a multi-processor system including several processors 2010 (e.g., two, four, eight, or another suitable number). Processor 2010 may be any suitable processor capable of executing instructions. For example, in various embodiments, processors 2010 may be general-purpose or embedded processors implementing any of a variety of Instruction Set Architectures (ISAs), such as the x86, PowerPC, SPARC, or MIPS ISAs, or any other suitable ISA. In a multiprocessor system, each of processors 2010 may typically, but need not necessarily, implement the same ISA.

The system memory 2020 may be configured to store program instructions 2022 and/or data 2032 accessible by the processor 2010. In various embodiments, the system memory 2020 may be implemented using any suitable memory technology, such as Static Random Access Memory (SRAM), synchronous dynamic ram (sdram), non-volatile/flash type memory, or any other type of memory. In the illustrated embodiment, the program instructions 2022 may be configured to implement various interfaces, methods, and/or data for controlling the operation of the camera 2090 and for capturing and processing images with the integrated camera 2090 or other methods or data, such as interfaces and methods for capturing, displaying, processing, and storing images captured with the camera 2090. In some embodiments, program instructions and/or data may be received, transmitted, or stored on a different type of computer-accessible medium, or the like, separate from system memory 2020 or computer system 2000.

In one embodiment, the I/O interface 2030 may be configured to coordinate I/O communication between the processor 2010, the system memory 2020, and any peripheral devices in the device, including the network interface 2040 or other peripheral device interfaces such as the input/output device 2050. In some embodiments, the I/O interface 2030 may perform any necessary protocol, timing, or other data transformations to convert data signals from one component (e.g., the system memory 2020) into a format suitable for use by another component (e.g., the processor 2010). In some embodiments, I/O interface 2030 may include support for devices attached, for example, through various types of peripheral device buses, such as a variant of the Peripheral Component Interconnect (PCI) bus standard or the Universal Serial Bus (USB) standard. In some embodiments, the functionality of I/O interface 2030 may be divided into two or more separate components, such as a north bridge and a south bridge, for example. Further, in some embodiments, some or all of the functionality of the I/O interface 2030 (such as an interface to the system memory 2020) may be incorporated directly into the processor 2010.

Network interface 2040 may be configured to allow data to be exchanged between computer system 2000 and other devices (e.g., operator or proxy devices) attached to network 2085, or between nodes of computer system 2000. In various embodiments, network 2085 may include one or more networks, including but not limited to: a Local Area Network (LAN) (e.g., ethernet or an enterprise network), a Wide Area Network (WAN) (e.g., the internet), a wireless data network, some other electronic data network, or some combination thereof. In various embodiments, network interface 2040 may support communication via a wired or wireless general purpose data network (such as any suitable type of ethernet network); communication via a telecommunications/telephony network (such as an analog voice network or a digital fiber optic communication network); communication via storage area networks (such as fibre channel SANs), or via any other suitable type of network and/or protocol.

The input/output devices 2050 may include, in some embodiments, one or more display terminals, keyboards, keypads, touch pads, scanning devices, voice or optical recognition devices, or any other devices suitable for entering or accessing data by the computer system 2000. Multiple input/output devices 2050 may be present in computer system 2000 or may be distributed across various nodes of computer system 2000. In some embodiments, similar input/output devices may be separate from computer system 2000 and may interact with one or more nodes of computer system 2000 via a wired or wireless connection (such as through network interface 2040).

As shown in fig. 10, the memory 2020 may include program instructions 2022 which are executable by the processor to implement any elements or actions for supporting the integrated camera 2090, including but not limited to image processing software and interface software for controlling the camera 2090. In some embodiments, the images captured by the camera 2090 may be stored to the memory 2020. Further, metadata for images captured by the camera 2090 may be stored to the memory 2020.

Those skilled in the art will appreciate that the computer system 2000 is merely illustrative and is not intended to limit the scope of embodiments. In particular, the computer systems and devices may include any combination of hardware or software that can perform the indicated functions, including computers, network devices, internet appliances, PDAs, wireless telephones, pagers, video or still cameras, and the like. The computer system 2000 may also be connected to other devices not shown, or otherwise operate as a standalone system. Further, the functionality provided by the illustrated components may be combined in fewer components or distributed in additional components in some embodiments. Similarly, in some embodiments, the functionality of some of the illustrated components may not be provided, and/or other additional functionality may be available.

Those skilled in the art will also recognize that while various items are shown as being stored in memory or on storage devices during use, these items, or portions thereof, may be transferred between memory and other storage devices for purposes of memory management and data integrity. Alternatively, in other embodiments, some or all of these software components may execute in memory on another device and communicate with the illustrated computer system 2000 via inter-computer communication. Some or all of the system components or data structures may also be stored (e.g., as instructions or structured data) on a computer-accessible medium or a portable article to be read by a suitable drive, various examples of which are described above. In some embodiments, instructions stored on a computer-accessible medium separate from computer system 2000 may be transmitted to computer system 2000 via transmission media or signals (such as electrical, electromagnetic, or digital signals transmitted via a communication medium such as a network and/or a wireless link). Various embodiments may also include receiving, transmitting or storing instructions and/or data implemented in accordance with the above description upon a computer-accessible medium. Generally speaking, a computer-accessible medium may include a non-transitory computer-readable storage medium or memory medium, such as a magnetic or optical medium, e.g., a disk or DVD/CD-ROM, a volatile or non-volatile medium such as RAM (e.g., SDRAM, DDR, RDRAM, SRAM, etc.), ROM, or the like. In some embodiments, a computer-accessible medium may include transmission media or signals, such as electrical, electromagnetic, or digital signals, conveyed via a communication medium such as a network and/or a wireless link.

In various embodiments, the methods described herein may be implemented in software, hardware, or a combination thereof. Additionally, the order of the blocks of a method may be changed, and various elements may be added, reordered, combined, omitted, modified, etc. Various modifications and changes will become apparent to those skilled in the art having the benefit of this disclosure. The various embodiments described herein are intended to be illustrative and not restrictive. Many variations, modifications, additions, and improvements are possible. Thus, multiple examples may be provided for components described herein as a single example. The boundaries between the various components, operations and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific example configurations. Other allocations of functionality are contemplated that may fall within the scope of claims that follow. Finally, structures and functionality presented as discrete components in the exemplary configurations may be implemented as a combined structure or component. These and other variations, modifications, additions, and improvements may fall within the scope of the embodiments as defined in the claims that follow.

PRIORITY INFORMATION

This patent application claims the benefit of priority from U.S. provisional patent application serial No. 62/726,163 entitled "POWER PRISM FOR folds", filed on 31/8/2018, the contents of which are incorporated herein by reference in their entirety.