Method for calibrating a projection device for a head-mounted display, and projection device for a head-mounted display for carrying out the method

Patent metadata

Field	Value
Publication number	US-11487126-B2
Application number	US-201816626453-A
Country	US
Kind code	B2
Filing date	Jun 21, 2018
Priority date	Jul 12, 2017
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

A method for calibrating a projection device for a head-mounted display includes scanning a light beam emitted by a light source over a scanning angle range by means of a reflection element such that the light beam deflected by the reflection element passes over a head-mounted display surface region of a deflection element arranged on a lens of the head-mounted display. The surface region has at least two adjustment markings arranged on the head-mounted display, each adjustment marking arranged at a specified position relative to the surface of the deflection element arranged on a lens of the head-mounted display. The method further includes determining in which scan setting of the reflection element the at least two adjustment markings are struck by the light beam.

First claim

The invention claimed is:

1. A method for calibrating a projection device for a pair of smart glasses, the method comprising:
scanning a light beam emitted by a light source with a reflection element over a scanning angle range such that the light beam deflected by the reflection element passes over a surface region of the smart glasses, which comprises at least two alignment marks arranged on the smart glasses, wherein each alignment mark of the at least two alignment marks is arranged at a predetermined position in relation to a surface of a deflection element arranged on a glasses lens of the smart glasses; and
determining at which respective scanning setting of the reflection element the at least two alignment marks are struck by the light beam by (i) deflecting the light beam in a predetermined direction with respective holographic or diffractive alignment elements, each of which is arranged on one of the at least two alignment marks, and (ii) detecting the light beam after the respective deflection.

2. The method as claimed in claim 1 , further comprising:
determining a unique functional relationship between the scanning setting of the reflection element and a point of incidence of the light beam on the surface of the smart glasses.

3. The method as claimed in claim 1 , wherein the determination of the respective scanning setting of the reflection element at which the at least two alignment marks are struck by the light beam includes detecting the light beam with detectors arranged on each alignment mark.

4. The method as claimed in claim 1 , wherein the light beam is reflected back by the respective holographic or diffractive alignment elements in a direction toward the reflection element.

5. The method as claimed in claim 1 , wherein the light beam is deflected by the respective holographic or diffractive alignment elements in a direction toward an eye lens of a user.

6. The method as claimed in claim 1 , wherein the light source is also used for image generation.

7. The method as claimed in claim 1 , wherein the method is stored in a computer program.

8. The method of claim 7 , wherein the computer program is stored on a machine-readable storage medium.

9. A projection device for a pair of smart glasses, the projection device comprising:
at least one light source configured to emit a light beam;
at least one deflection element arranged on a glasses lens of the smart glasses and configured to project an image onto a retina of a user of the smart glasses by deflecting and/or focusing the light beam on an eye lens of the user;
at least two alignment marks, each alignment mark of the at least two alignment marks arranged at a predetermined position in relation to a surface of the deflection element; and
a reflection element configured to scan the light beam over a scanning angle range such that the light beam deflected by the reflection element passes over a surface region of the smart glasses that comprises the at least two alignment marks,
wherein the projection device is configured to determine a respective scanning setting of the reflection element at which the at least two alignment marks are struck by the light beam by (i) deflecting the light beam in a predetermined direction with respective holographic or diffractive alignment elements, each of which is arranged on one of the at least two alignment marks, and (ii) detecting the light beam after the respective deflection.

10. The projection device as claimed in claim 9 , wherein the deflection element is arranged on a glasses lens of the pair of smart glasses.

11. The projection device as claimed in claim 9 , further comprising:
an electronic control unit configured to calibrate the projection device by operating the scanning device to scan the light beam over the scanning angle range and determining the respective scanning setting.

Assignees

• Bosch Gmbh Robert

Inventors

• Petersen Andreas
• Graf Tobias

Classifications

• G02B27/0172

  characterised by optical features · CPC title

• G02B27/0176 Primary

  characterised by mechanical features · CPC title

• G02B27/0179 Primary

  Display position adjusting means not related to the information to be displayed · CPC title

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B26/10

  Scanning systems · CPC title