TWI748815B - Optical lens device for head-mounted display and its manufacturing method and mold - Google Patents

Abstract

An optical lens device for a head-mounted display includes a transparent supporting substrate and a Fresnel lens arranged on the supporting substrate. The Fresnel lens includes a central lens unit and a plurality of prism units. The prism units are arranged from near to far with respect to the central lens unit. Each prism unit has a bottom, a draft surface and an inclined surface. The bottom faces the support substrate; the draft surface extends away from the support substrate from the bottom; the inclined surface extends away from the support substrate from the bottom to intersect the draft surface to form a top end. The measuring height of each prism unit from the bottom to the top is not more than 75 μm, and the width of the bottom is not more than 250 μm. The optical lens device of the present invention has a thin thickness, is not easy to be broken and flexed, does not produce visually disturbing lines, and can also maintain a high transfer rate to prevent the visual image from being deformed.

Description

Optical lens device for head-mounted display and its manufacturing method and mold

The present invention relates to an optical lens device, in particular to an optical lens device used in a head-mounted display (HMD), and a manufacturing method and mold thereof.

Generally, an optical lens device for condensing or dispersing light needs to use a lens with a thickness of a millimeter scale, and an optical lens device with a Fresnel lens structure helps to achieve a thinner device. However, when an optical lens device with a Fresnel lens structure is used in a head-mounted display (HMD), interference lines are often generated in human vision.

US patent US 10359545 B2 discloses a curved Fresnel lens used in a head-mountable apparatus. The angle of the draft facet is set based on the refractive index to be consistent with the curved path of the light (congruent). ), which can effectively reduce visual interference lines. However, the curvature of the lens is strictly limited, and it cannot avoid the problem that the visual image is easily deformed.

Therefore, the first objective of the present invention is to provide an optical lens device for a head-mounted display, which can overcome the above-mentioned shortcomings of the prior art.

Therefore, the optical lens device for a head-mounted display of the present invention includes a transparent supporting substrate and a Fresnel lens arranged on the supporting substrate. The Fresnel lens includes a central lens unit and a plurality of prism units. The prism units are arranged from near to far with respect to the central lens unit. Each prism unit has a bottom, a draft facet and a slope facet. The bottom faces the support substrate; the draft surface extends away from the support substrate from the bottom; the inclined surface extends away from the support substrate from the bottom to intersect the draft surface to form an apex. The measuring height of each prism unit from the bottom to the top is not more than 75 μm, and the width of the bottom is not more than 250 μm.

Therefore, the second objective of the present invention is to provide a method of manufacturing an optical lens device for a head-mounted display, including: Provide a transparent supporting substrate; A mold is provided, and the mold includes a central lens forming body and a plurality of prism forming grooves arranged from near to far relative to the central lens forming body. Each prism forming groove has an opening, a bottom end, a draft surface and an inclined surface. The bottom end is opposite to the opening; the draft surface extends from the opening to the bottom end; the inclined surface extends from the opening to the bottom end to meet the draft surface. The measuring depth from the opening to the bottom end is not more than 75 μm, and the distance between the draft surfaces of the grooves formed by two adjacent prisms is not more than 250 μm; Disposing an ultraviolet curable resin on at least one of the supporting substrate and the mold; Molding the ultraviolet curable resin with the mold; Irradiating the ultraviolet curable resin with ultraviolet light to form a Fresnel lens on the supporting substrate, the Fresnel lens including a central lens unit and a plurality of prism units; and The Fresnel lens is released from the mold.

Therefore, the third object of the present invention is to provide a mold for manufacturing an optical lens device of a head mounted display, which includes a central lens forming body and a plurality of prism forming grooves. The prism forming grooves are arranged from near to far relative to the central lens forming body. Each prism forming groove has an opening, a bottom end, a draft surface and an inclined surface. The bottom end is opposite to the opening; the draft surface extends from the opening to the bottom end; the inclined surface extends from the opening to the bottom end to meet the draft surface. The measuring depth from the opening to the bottom end is not more than 75 μm, and the distance between the draft surfaces of the grooves formed by two adjacent prisms is not more than 250 μm.

The effect of the present invention is that the thickness of the optical lens device for the head-mounted display is thin, and it is not easy to break and bend, and it will not produce interference lines on the human body during use, and it can also maintain a high transfer rate. The visual image is deformed.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same numbers.

The content of the present invention will be described in detail below:

The optical lens device for a head-mounted display of the present invention includes a transparent supporting substrate 1 and a Fresnel lens 2 arranged on the supporting substrate 1. The Fresnel lens 2 includes a central lens unit 21 and a plurality of prism units 22. The prism units 22 are arranged from near to far relative to the central lens unit 21. Each prism unit 22 has a bottom 221, a draft surface 222 and an inclined surface 223. The bottom 221 faces the support substrate 1; the draft surface 222 extends away from the support substrate 1 from the bottom 221; the inclined surface 223 extends away from the support substrate 1 from the bottom 221 to meet the draft surface 222 A top 224 is formed. The measuring height of each prism unit 22 from the bottom 221 to the top 224 is not more than 75 μm, and the width of the bottom 221 is not more than 250 μm.

Preferably, the width of the bottom 221 ranges from 30 to 200 μm.

Preferably, the height of each prism unit 22 ranges from 2 to 25 μm.

Preferably, the Fresnel lens 2 is made of a (meth)acrylic UV curable resin 20.

Preferably, the supporting substrate 1 is made of a material selected from polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA) or a combination thereof have to.

Preferably, the thickness of the supporting substrate 1 is not greater than 600 μm. More preferably, the thickness of the supporting substrate 1 ranges from 50 to 600 μm.

Preferably, the supporting substrate 1 is a curved surface with a radius of curvature ranging from 0.5 cm to 15 cm.

Preferably, the top end 224 of each prism unit 22 is rounded with a radius of curvature not greater than 2 μm.

Preferably, the draft surface 222 of each prism unit 22 and the inclined surface 223 of the adjacent prism unit 22 intersect to form a groove bottom end 225, and the groove bottom end 225 is a circle with a radius of curvature not greater than 2 μm. Horn.

In some embodiments of the present invention, the prism units 22 are arranged in concentric circles. In other embodiments of the present invention, the prismatic units 22 are arranged in parallel to each other.

Preferably, the optical lens device of the present invention further includes a protective film 5 disposed on at least one of the Fresnel lens 2 and the supporting substrate 1.

Preferably, the central lens unit 21 is convex or concave. In the embodiment of the present invention, the central lens unit 21 is convex.

The method for manufacturing an optical lens device for a head-mounted display of the present invention includes: Provide a transparent supporting substrate 1; A mold 3 is provided, and the mold 3 includes a central lens forming body 31 and a plurality of prism forming grooves 32 arranged from near to far relative to the central lens forming body 31. Each prism forming groove 32 has an opening 320, a bottom end 324, a draft surface 322 and an inclined surface 323. The bottom end 324 is opposite to the opening 320; the draft surface 322 extends from the opening 320 to the bottom end 324; the inclined surface 323 extends from the opening 320 to the bottom end 324 to meet the draft surface 322. The measuring depth from the opening 320 to the bottom end 324 is not more than 75 μm, and the distance between the draft surfaces 322 of the grooves 32 formed by two adjacent prisms is not more than 250 μm; Disposing an ultraviolet curable resin 20 on at least one of the supporting substrate 1 and the mold 3; Molding the ultraviolet curable resin 20 with the mold 3; Irradiate the ultraviolet light curable resin 20 with ultraviolet light 4 to form a Fresnel lens 2 on the support substrate 1. The Fresnel lens 2 includes a central lens unit 21 and a plurality of prism units 22; and The Fresnel lens 2 is released from the mold 3.

Preferably, the distance between the draft surfaces 322 of the two adjacent prism forming grooves 32 ranges from 30 to 200 μm.

Preferably, the depth of each prism forming groove 32 ranges from 2 to 25 μm.

Preferably, the Fresnel lens 2 is made of a (meth)acrylic UV curable resin 20.

Preferably, the supporting substrate 1 is made of a material selected from polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA) or a combination thereof have to.

In some embodiments of the present invention, the prism forming grooves 32 are arranged in concentric circles. In other embodiments of the present invention, the prism forming grooves 32 are arranged parallel to each other.

Preferably, the manufacturing method of the present invention further includes providing a protective film 5 on at least one of the Fresnel lens 2 and the supporting substrate 1.

Preferably, the central lens forming body 31 is concave or convex. In the embodiment of the present invention, the central lens forming body 31 is concave.

Preferably, the mold 3 is a roller mold 3, and the central lens forming body 31 and the prism forming grooves 32 are provided on the surface of the roller mold 3.

The present invention will be further illustrated with the following examples, but it should be understood that these examples are for illustrative purposes only and should not be construed as limitations to the implementation of the present invention.

Referring to FIG. 1, a first embodiment of an optical lens device for a head-mounted display of the present invention includes a transparent support substrate 1 and a Fresnel lens 2 disposed on the support substrate 1. The Fresnel lens 2 includes a convex central lens unit 21 and a plurality of prism units 22.

The prism units 22 are arranged in concentric circles from near to far relative to the central lens unit 21. Each prism unit 22 has a bottom 221, a draft surface 222 and an inclined surface 223. The bottom 221 faces the support substrate 1; the draft surface 222 extends away from the support substrate 1 from the bottom 221; the inclined surface 223 extends away from the support substrate 1 from the bottom 221 to meet the draft surface 222 A top 224 is formed. The draft surface 222 of each prism unit 22 and the inclined surface 223 of the adjacent prism unit 22 intersect to form a groove bottom 225. In this embodiment, the measured height of each prism unit 22 from the bottom 221 to the top 224 is about 15 μm, and the width of the bottom 221 is about 180 μm.

In this embodiment, the supporting substrate 1 has a thickness of about 188 μm and a curved surface with a radius of curvature of about 0.5 cm.

In this embodiment, the top end 224 of each prism unit 22 is rounded with a radius of curvature of about 2 μm, and the bottom end 225 of the groove is rounded with a radius of curvature of about 2 μm.

Referring to FIGS. 2, 4, and 5, a specific embodiment of the manufacturing method of the optical lens device of the first embodiment is roll-to-roll processing, which includes the following steps:

A transparent PET supporting substrate 1 is provided. A (meth)acrylic ultraviolet light curable resin 20 is coated on the PET support substrate 1. In this embodiment, the ultraviolet curable resin 20 is an ultraviolet curable resin purchased from Sil-More Industrial Ltd. and the product model is x-8060-1.

A roller mold 3 is provided, and the roller mold 3 includes a concave central lens forming body 31 and a plurality of prism forming grooves 32 arranged on the surface. The prism forming grooves 32 are arranged concentrically from near to far relative to the central lens forming body 31. Each prism forming groove 32 has an opening 320, a bottom end 324, a draft surface 322 and an inclined surface 323. The bottom end 324 is opposite to the opening 320; the draft surface 322 extends from the opening 320 to the bottom end 324; the inclined surface 323 extends from the opening 320 to the bottom end 324 to meet the draft surface 322. In this embodiment, the measuring depth range from the opening 320 to the bottom end 324 is 15 μm, and the distance between the draft surfaces 322 of the two adjacent prism forming grooves 32 is 180 μm. The bottom end 324 of each prism forming groove 32 has a sharp angle, and the intersection of the draft surface 322 of each prism forming groove 32 and the inclined surface 323 of the adjacent prism forming groove 32 has a sharp angle.

The ultraviolet curable resin 20 is molded with the roller mold 3.

The ultraviolet curable resin 20 is irradiated with ultraviolet light 4 having a wavelength of 365 nm at 40° C. (irradiation amount is about 250 mJ/cm ² ) to form the Fresnel lens 2 on the PET support substrate 1. The Fresnel lens 2 includes the central lens unit 21 and the prism units 22 (refer to FIG. 1).

The Fresnel lens 2 is separated from the roller mold 3.

A protective film 5 is formed on the Fresnel lens 2 and the supporting substrate 1 respectively. The material of the protective film 5 is selected from UV-curable hard coating (pencil hardness above 2H), polyethylene or polypropylene.

3 to 5, another specific embodiment of the manufacturing method of the optical lens device of the first embodiment is a roll-to-roll process, which includes the following steps:

A transparent PC supporting substrate 1 is provided.

A roller mold 3 is provided, and the roller mold 3 is as described in the previous specific embodiment. A (meth)acrylic ultraviolet light curable resin 20 is coated on the roller mold 3. In this embodiment, the ultraviolet curable resin 20 is an ultraviolet curable resin purchased from Sil-More Industrial Ltd. and the product model is x-8060-1.

The ultraviolet curable resin 20 is molded with the roller mold 3.

The ultraviolet light curable resin 20 is irradiated with ultraviolet light 4 having a wavelength of 365 nm at 40°C (irradiation amount is about 250 mJ/cm ² ) to form the Fresnel lens 2 on the PC support substrate 1, the The Fresnel lens 2 includes the central lens unit 21 and the prism units 22 (refer to FIG. 1).

The Fresnel lens 2 is separated from the roller mold 3.

A protective film 5 is formed on the Fresnel lens 2 and the supporting substrate 1 respectively. The material of the protective film 5 is as described in the previous specific embodiment.

Referring to FIG. 6, a second embodiment of an optical lens device for a head-mounted display of the present invention is similar to the above-mentioned first embodiment. The difference is that the Fresnel lens 2 of the second embodiment includes a flat surface. A central lens unit 21 and a plurality of prismatic units 22 are formed.

Referring to FIG. 7, a third embodiment of an optical lens device for a head-mounted display of the present invention includes a transparent supporting substrate 1 and a Fresnel lens 2 disposed on the supporting substrate 1. The Fresnel lens 2 includes a convex central lens unit 21 and a plurality of prism units 22.

The prism units 22 are arranged parallel to each other from near to far relative to the central lens unit 21. Each prism unit 22 has a bottom 221, a draft surface 222 and an inclined surface 223. The bottom 221 faces the support substrate 1; the draft surface 222 extends away from the support substrate 1 from the bottom 221; the inclined surface 223 extends away from the support substrate 1 from the bottom 221 to meet the draft surface 222 A top 224 is formed. The draft surface 222 of each prism unit 22 and the inclined surface 223 of the adjacent prism unit 22 intersect to form a groove bottom 225. In this embodiment, the measured height of each prism unit 22 from the bottom 221 to the top 224 is about 15 μm, and the width of the bottom 221 is about 180 μm.

In this embodiment, the supporting substrate 1 has a thickness of about 188 μm and a curved surface with a radius of curvature of about 0.5 cm.

In this embodiment, the top end 224 of each prism unit 22 is rounded with a radius of curvature of about 2 μm, and the bottom end 225 of the groove is rounded with a radius of curvature of about 2 μm.

The method of manufacturing the optical lens device of the third embodiment is similar to the method of manufacturing the optical lens device of the first embodiment described above. The difference is that the prism forming grooves 32 of the roller mold 3 of the third embodiment are opposite to each other. The central lens forming bodies 31 are arranged parallel to each other from near to far.

In summary, the optical lens device used in the head-mounted display of the present invention is thin in thickness, and can be curved with a radius of curvature of 0.5 cm without breaking and bending, and will not produce interference lines on human vision during use. . In addition, the structural dimension error between the mold 3 used to manufacture the optical lens device and the optical lens device manufactured therefrom is small (that is, the high transfer rate is maintained, and the error is less than about 10%), and the rounded corners of the prism units 22 The radius of curvature is small (approximately a sharp angle), so the optical lens device is not easy to deform the visual image when in use, so it can indeed achieve the purpose of the invention.

However, the above are only examples of the present invention, and should not be used to limit the scope of implementation of the present invention, all simple equivalent changes and modifications made in accordance with the scope of the patent application of the present invention and the content of the patent specification still belong to This invention patent covers the scope.

1: Support substrate 2: Fresnel lens 20: UV curable resin 21: Central lens unit 22: Prism unit 221: bottom 222: Draft surface 223: Inclined Surface 224: top 225: The bottom of the groove 3: Mould 31: The central lens forms the shape 32: Prism forms grooves 320: opening 322: Draft surface 323: Inclined surface 324: Bottom 4: Ultraviolet light 5: Protective film

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: [Figure 1] is a schematic cross-sectional view of the first embodiment of the optical lens device for head-mounted displays of the present invention; [Fig. 2] is a step flow chart of a specific embodiment of the manufacturing method of the optical lens device of the first embodiment; [Figure 3] is a flowchart of another specific embodiment of the method of manufacturing the optical lens device of the first embodiment; [Figure 4] is a schematic diagram of the process equipment configuration of the optical lens device of the first embodiment; [FIG. 5] is a schematic perspective view of a mold used to manufacture the optical lens device of the first embodiment; [FIG. 6] is a schematic cross-sectional view of the second embodiment of the optical lens device for a head-mounted display of the present invention; and [Fig. 7] is a three-dimensional schematic diagram of the third embodiment of the optical lens device for a head-mounted display of the present invention.

1: Support substrate

2: Fresnel lens

21: Central lens unit

22: Prism unit

221: bottom

222: Draft surface

223: Inclined Surface

224: top

225: The bottom of the groove

Claims (23)

An optical lens device for a head-mounted display, comprising: a transparent support substrate; and a Fresnel lens arranged on the support substrate, including a central lens unit and a plurality of prism units, the prism units Relative to the central lens unit arranged from near to far, each prism unit has a bottom facing the supporting substrate, a draft surface extending away from the supporting substrate from the bottom, and a drawing surface extending away from the supporting substrate from the bottom Extending to meet the drafting surface to form an inclined surface at the top, the measuring height of each prism unit from the bottom to the top is not more than 75μm, the width of the bottom is not more than 250μm, and the top of each prism unit has a curvature For rounded corners with a radius of no more than 2 μm, the draft surface of each prism unit and the inclined surface of the adjacent prismatic unit intersect to form a groove bottom end, and the groove bottom end has a rounded corner with a curvature radius of no more than 2 μm. The optical lens device according to claim 1, wherein the width of the bottom is in the range of 30 to 200 μm. The optical lens device according to claim 1, wherein the height of each prism unit ranges from 2 to 25 μm. The optical lens device according to claim 1, wherein the Fresnel lens is made of a (meth)acrylic ultraviolet light curable resin. The optical lens device according to claim 1, wherein the supporting substrate is made of a material selected from polyethylene terephthalate, polycarbonate, polymethyl methacrylate, or a combination thereof . The optical lens device according to claim 1, wherein the thickness of the supporting substrate is not greater than 600 μm. The optical lens device according to claim 1, wherein the supporting substrate is a curved surface with a radius of curvature ranging from 0.5 to 15 cm. The optical lens device according to claim 1, wherein the prism units are arranged in concentric circles. The optical lens device according to claim 1, wherein the prism units are arranged in parallel to each other. The optical lens device according to claim 1, further comprising a protective film disposed on at least one of the Fresnel lens and the supporting substrate. The optical lens device according to claim 1, wherein the central lens unit is convex or concave. A method for manufacturing an optical lens device for a head-mounted display, comprising: providing a transparent supporting substrate; providing a mold, the mold including a central lens forming body and a plurality of shapes from near to far relative to the central lens forming body Arranged prism forming grooves, each prismatic forming groove has an opening, a bottom end opposite to the opening, a draft surface extending from the opening to the bottom end, and a drawing surface extending from the opening to the bottom end to interact with the drawing The measuring depth from the opening to the bottom end of the inclined surface where the die surfaces meet is not more than 75μm, the distance between the draft surfaces of two adjacent prisms forming grooves is not more than 250μm, and the bottom end of each prism forming groove is a sharp angle. The intersection of the draft surface of each prism-forming groove and the inclined surface of the adjacent prism-forming groove forms a sharp angle; at least one of the supporting substrate and the mold is provided with an ultraviolet curable resin; The ultraviolet light curable resin is molded with the mold; the ultraviolet light curable resin is irradiated with ultraviolet light to form a Fresnel lens on the supporting substrate, and the Fresnel lens includes a central lens unit and multiple lenses. A prism unit; and the Fresnel lens is released from the mold. The manufacturing method according to claim 12, wherein the distance between the draft surfaces of two adjacent prism forming grooves ranges from 30 to 200 μm. The manufacturing method according to claim 12, wherein the depth of each prism forming groove is 2-25 μm. The manufacturing method according to claim 12, wherein the Fresnel lens is made of a (meth)acrylic ultraviolet light curable resin. The manufacturing method according to claim 12, wherein the supporting substrate is made of a material selected from polyethylene terephthalate, polycarbonate, polymethyl methacrylate, or a combination thereof. The manufacturing method according to claim 12, wherein the prism forming grooves are arranged in concentric circles. The manufacturing method according to claim 12, wherein the prism forming grooves are arranged parallel to each other. The manufacturing method according to claim 12, further comprising providing a protective film on at least one of the Fresnel lens and the supporting substrate. The manufacturing method according to claim 12, wherein the central lens forming body is concave or convex. The manufacturing method according to claim 12, wherein the mold is a roller mold, and the central lens forming body and the prism forming grooves are provided on the surface of the roller mold. A mold for manufacturing an optical lens device for a head-mounted display, comprising: a central lens forming body; and a plurality of prism forming grooves arranged from near to far relative to the central lens forming body, and each prism forming groove has a Opening, a bottom end opposite to the opening, a draft surface extending from the opening to the bottom end, and an inclined surface extending from the opening to the bottom end to meet the draft surface, from the opening to the bottom The measuring depth of the end is not more than 75μm, the distance between the draft surfaces of two adjacent prisms forming grooves is not more than 250μm, the bottom end of each prism forming groove is a sharp angle, and the draft surface of each prism forming groove is adjacent to it The intersection of the inclined surfaces of the prism forming the groove is a sharp angle. The mold according to claim 22, wherein the mold is a roller mold, and the central lens forming body and the prism forming grooves are provided on the surface of the roller mold.

Images