CN-121986026-A - Method and arrangement for joining transparent plates and for manufacturing light-guiding optical elements

Abstract

Methods for joining parallel facing transparent plates are provided. The plates are arranged in a stack with a lateral offset between one or more pairs of adjacent plates to define a plate step. An adhesive is disposed at the interfaces between adjacent plates of the stack, and a coating is disposed at one face at each of the interfaces. In one set of methods, the stack is placed between a pair of pressing members, and the compensating members are arranged in a stepped configuration corresponding to the plate steps. Pressure is then applied to the plate via the pressing member. In another set of methods, the stack is placed in a flexible container having an opening, and gas is removed from the container via the opening to deform the container around the stack, which applies pressure on the sides of the stack and causes excess adhesive to be redistributed from the interface.

Inventors

• EDGAR FRIEDMAN
• Yeshea Danzig
• A Mier.shapila
• Ronin cheriki

Assignees

• 鲁姆斯有限公司

Dates

Publication Date

20260505

Application Date

20250108

Priority Date

20240117

Claims (20)

1. 1. A method, comprising: arranging a plurality of parallel facing transparent plates in a stack having a lateral offset between one or more pairs of adjacent transparent plates to define one or more plate steps, wherein an optical adhesive is disposed at an interface between adjacent transparent plates of the stack, and wherein a coating is disposed at one face at each of the interfaces, the stack being placed between a first pressing member and a second pressing member; Providing a plurality of compensation members in a stepped configuration between the first pressing member and the second pressing member, wherein the one or more plate steps and the stepped configuration are correspondingly configured such that the compensation members compensate for offset between the one or more pairs of adjacent transparent plates, and Pressure is applied to the plurality of transparent plates via the first pressing member and the second pressing member.
2. 2. The method of claim 1, wherein the stepped configuration of the compensation member is provided at least in part by a size of the compensation member.
3. 3. The method of claim 1, wherein at least some of the compensation members have an adjustable height, wherein the height is measured along a dimension perpendicular to the parallel faces of the transparent plates.
4. 4. The method of claim 1, wherein the plurality of compensation members includes a first set of compensation members associated with the first compression member and a second set of compensation members associated with the second compression member.
5. 5. The method of claim 1, wherein the plurality of compensation members comprises a first set of compensation members associated with a first end region of the stack and compensating for an offset between one or more pairs of adjacent transparent plates at the first end region of the stack and a second set of compensation members associated with a second end region of the stack and compensating for an offset between one or more pairs of adjacent transparent plates at the second end region of the stack.
6. 6. The method of claim 1, wherein the stack is placed between a first pressing member and a second pressing member such that a first block member is positioned between the first pressing member and a first transparent plate at a top end of the stack and such that a second block member is positioned between the second pressing member and a second transparent plate at a bottom end of the stack.
7. 7. The method of claim 6, further comprising deploying a first insulating member between the first block member and the first pressing member, and deploying a second insulating member between the second block member and the second pressing member.
8. 8. The method of claim 1, wherein the coating provides partially reflective optical properties.
9. 9. The method of claim 8, further comprising: solidifying the adhesive so that the stack forms a joined stack, and The bonded stack is cut along at least two parallel cutting planes inclined obliquely relative to the face of the transparent plate to extract one or more parallel facing substrates having a plurality of mutually parallel partially reflective inner surfaces formed from the interface.
10. 10. The method of claim 1, further comprising: placing the stack in a flexible container having an opening, and Removing gas from the container via the opening to deform the container around the stack such that an applied pressure is exerted on the sides of the stack and a pressure differential is created within the container at a region around the stack, wherein the applied pressure and the pressure differential redistribute excess adhesive from the interface to the region.
11. 11. A pressing arrangement comprising: a first pressing member; A second pressing member opposite the first pressing member, the first and second pressing members being configured to be spaced apart to accommodate a stack of parallel facing transparent plates arranged in the stack with a lateral offset between one or more pairs of adjacent transparent plates to define one or more plate steps, wherein an optical adhesive is disposed at an interface between adjacent transparent plates of the stack, and wherein a coating is disposed at one face at each of the interfaces; A plurality of compensation members disposed in a stepped configuration between the first pressing member and the second pressing member, wherein the one or more plate steps and the stepped configuration are correspondingly configured such that the compensation members compensate for offset between the one or more pairs of adjacent transparent plates, and An actuator associated with at least one of the first pressing member or the second pressing member and configured to move at least one of the first pressing member or the second pressing member to apply pressure to the plurality of transparent plates.
12. 12. A method, comprising: arranging a plurality of parallel facing transparent plates in a staggered stack, wherein an optical adhesive is disposed at interfaces between adjacent transparent plates of the stack, and wherein a coating is disposed at one face at each of the interfaces; placing the stack in a flexible container having an opening, and Removing gas from the container through the opening to deform the container around the stack such that an applied pressure is exerted on sides of the stack and a pressure differential is created within the container at a region around the stack, wherein the applied pressure and the pressure differential redistribute excess adhesive from the interface to the region.
13. 13. The method of claim 12, further comprising: Inflating the container, and At least some of the redistributed excess adhesive is removed.
14. 14. The method of claim 13, further comprising repeatedly removing gas from the container, inflating the container, and removing at least some of the redistributed excess adhesive until a stop condition is met.
15. 15. The method of claim 12, further comprising thinning the adhesive disposed at the interface by diluting the adhesive with an additive to reduce the viscosity of the adhesive.
16. 16. The method of claim 15, wherein the additive comprises a solvent.
17. 17. The method of claim 15, further comprising: Cutting the stack along at least two parallel cutting planes inclined obliquely to the face of the transparent plate to extract at least one parallel-facing substrate having a plurality of mutually parallel inner surfaces formed from the interface, and One or more of the at least one substrate is placed in a chamber to accelerate evaporation of the solvent.
18. 18. The method of claim 12, further comprising: the adhesive is cured such that the stack forms a bonded stack.
19. 19. The method of claim 18, wherein setting the adhesive is performed while the container is deformed around the stack.
20. 20. The method of claim 12, wherein the coating provides partially reflective optical properties.

Description

Method and arrangement for joining transparent plates and for manufacturing light-guiding optical elements Cross Reference to Related Applications The present application claims priority from U.S. provisional patent application No. 63/621,601, filed on day 17 at 1 at 2024, and U.S. provisional patent application No. 63/636,889, filed on day 22 at 4 at 2024, the disclosures of which are incorporated herein by reference in their entirety. Technical Field The present disclosure relates to optical systems, and in particular, the present disclosure relates to methods and arrangements for joining transparent plates, and methods for manufacturing Light-guiding optical elements (LOEs) from the joined transparent plates. Background Various types of displays (e.g., near-Eye displays) require a large aperture to cover the area where the eyes of the viewer (i.e., of the user, of the viewer) are located (commonly referred to as Eye-movement Box (EMB) -or EMB). In order to achieve a compact device, the image to be projected into the observer's eye is generated by a small optical image generator (projector) with a small optical aperture. An optical arrangement for a display may employ a light guide optical element (LOE) to expand an input image in one or more dimensions. Of particular relevance to the present disclosure is a reflective LOE, wherein the LOE is implemented as a transparent substrate bounded by two parallel major outer surfaces configured to support light propagation therebetween via (total) internal reflection, and wherein image expansion is performed by a set of mutually parallel partially reflective inner surfaces (or "facets") located between the major outer surfaces. The collimated image propagating within the LOE is gradually partially deflected by the set of facets, thereby effecting aperture expansion. Conventional LOE production methods rely on stacking and joining parallel facing transparent plates provided with an at least partially reflective coating at the interface between the plates. The bonded stack is cut along parallel cutting planes that are inclined obliquely to the face of the transparent plate such that the interface forms a facet. The bonding of the stack is achieved by an optical adhesive disposed between adjacent plates. Fig. 1 shows a conventional stack 1 of transparent sheets, showing parallel cutting planes 15 inclined obliquely to the sheet surface. The stack 1 is shown capped (at the top and bottom) with an additional transparent plate having a thickness several times the thickness of the other plates. In order for the final LOE product to have optimal mechanical and optical properties, the adhesive layer between the plates should be as thin as possible. This may be achieved by applying pressure to the stack via the top and bottom plates of the stack using a pressing mechanism. However, if uniform pressure is not applied, conventional pressing techniques may cause bending or deformation of the plate. Furthermore, to reduce the amount of scrap, the stacks are typically arranged as staggered stacks 1', as shown in fig. 2. However, using conventional pressing techniques on staggered stacks may not be able to achieve optimal mechanical and optical properties. Disclosure of Invention The present disclosure provides methods and arrangements for bonding transparent plates and for manufacturing light guide optical elements (LOEs) from bonded transparent plates. According to the teachings of the embodiments of the present disclosure, there is provided a method comprising arranging a plurality of parallel-facing transparent plates in a stack having a lateral offset between one or more pairs of adjacent transparent plates to define one or more plate steps, an optical adhesive disposed at an interface between adjacent transparent plates of the stack and a coating disposed at one face at each of the interfaces, the stack being placed between a first pressing member and a second pressing member, disposing a plurality of compensating members in a stepped configuration between the first pressing member and the second pressing member, the one or more plate steps and the stepped configuration being correspondingly configured such that the compensating members compensate for the offset between the one or more pairs of adjacent transparent plates, and applying pressure to the plurality of transparent plates via the first pressing member and the second pressing member. Optionally, the stepped configuration of the compensation member is provided at least in part by the dimensions of the compensation member. Optionally, at least some of the compensation members have an adjustable height measured along a dimension perpendicular to the parallel faces of the transparent plates. Optionally, the plurality of compensating members includes a first set of compensating members associated with the first pressing member and a second set of compensating members associated with the second pressing member. Optional