Head-mounted display device and control method for the head-mounted display device

• US 9,678,346 B2
• Filed: 12/10/2014
• Issued: 06/13/2017
• Est. Priority Date: 03/24/2011
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Nakada, Yuji, Saito, Hitoshi
• Primary Examiner(s): Spar, Ilana
• Assistant Examiner(s): Heyi, Henok
• Application Number:
  US14/566,014
• Publication Number:
  US 20150097873A1
• Time in Patent Office: 916 Days
• Field of Search: None
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• CPC Class Codes: G02B 27/0093 with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

A head-mounted display device includes: an image display unit including an image-light generating unit that generates image light representing an image and emits the image light and a light guide unit that guides the emitted image light to the eye of a user, the image display unit being for causing the user to visually recognize a virtual image; and a control unit that includes an operation surface, is connected to the image display unit, and controls image display by the image display unit. When it is assumed that the user shifts the user'"'"'s attention from the virtual image, the control unit adjusts the luminance of the image-light generating unit or adjusts the image light generated by the image-light generating unit to reduce the visibility of the virtual image.

Claims

1. A head-mounted display device comprising:

an image display unit including an image-light generating unit that generates image light representing an image and emits the image light and a light guide unit that guides the emitted image light to an eye of a user, the image display unit causing the user to visually recognize a virtual image and an external image that is external to the head-mounted display device;

a control unit that includes an operation surface, is connected to the image display unit and controls image display by the image display unit, wherein

responsive to an indication that the user has shifted attention from the virtual image, the control unit adjusts luminance of the image-light generating unit or adjusts the image light generated by the image-light generating unit to reduce visibility of the virtual image while maintaining visibility of the external image;

a head-side light emitting unit that is arranged in the image display unit and emits invisible light;

a control-unit-side light emitting unit that is arranged in the operation surface and emits invisible light; and

a contact detecting unit that is arranged in the control unit and for detecting contact with the control unit, wherein

when the contact with the control unit is detected, the control unit causes the head-side light emitting unit to emit the invisible light and causes the control-unit-side light emitting unit to emit the invisible light.

2. The head-mounted display device according to claim 1, further comprising a direction determining unit that determines whether the user faces the operation surface of the control unit, wherein

when it is determined that the user faces the operation surface, the control unit adjusts the luminance of the image-light generating unit or adjusts the image light generated by the image-light generating unit to reduce the visibility of the virtual image.

3. The head-mounted display device according to claim 2, further comprising:

a control-unit-side light receiving unit that is arranged on the operation surface and receives the emitted invisible light, wherein

the direction determining unit determines whether the user faces the operation surface of the control unit by determining, using an output signal of the control-unit-side light receiving unit, whether the operation surface and the image display unit are opposed to each other.

4. The head-mounted display device according to claim 3, further comprising:

a head-side light receiving unit that is arranged in the image display unit and receives the emitting invisible light, wherein

the control unit causes the head-side light emitting unit and the control-unit-side light emitting unit to alternately emit the invisible light, and

the direction determining unit determines whether the user faces the operation surface of the control unit by determining, using an output signal of the control-unit-side light receiving unit and an output signal of the head-side light receiving unit, whether the operation surface and the image display unit are opposed to each other.

5. The head-mounted display device according to claim 3, wherein

the invisible light emitted by the head-side light emitting unit includes identification information for identifying the image display unit according to pulse modulation of the invisible light,

the control unit includes a storing unit that stores authentication information for authenticating the image display unit connected to the control unit, and

the direction determining unit further includes an authenticating unit that authenticates the image display unit by acquiring the identification information from an output signal of the control-unit-side light receiving unit and performing a search as to whether the acquired identification information is included in the authentication information.

6. The head-mounted display device according to claim 2, further comprising:

an acceleration-information detecting unit that is arranged in the image display unit and for detecting acceleration information of the image display unit; and

an angular-velocity-information detecting unit that is arranged in the image display unit and for detecting angular velocity information of the image display unit, wherein

the direction determining unit determines whether the user faces the operation surface of the control unit by determining, using the detected acceleration information and the detected angular velocity information, whether the operation surface and the image display unit are opposed to each other.

7. The head-mounted display device according to claim 2, wherein

the image-light generating unit includes:

a display device that generates the image; and

a light source that emits image light representing the generated image, and

when it is determined that the user faces the operation surface, the control unit adjusts the luminance of the image-light generating unit by turning off or reducing illumination light of the light source.

8. The head-mounted display device according to claim 2, wherein

the image-light generating unit includes:

a display device that generates the image; and

a light source including plural light emitting members for emitting image light representing the generated image, and

when it is determined that the user faces the operation surface of the control unit, the control unit adjusts the luminance of the image-light generating unit by turning off or reducing illumination light of at least a part of the plural light emitting members.

9. The head-mounted display device according to claim 2, wherein the control unit transmits image data to the image-light generating unit and, when it is determined that the user faces the operation surface, the control unit adjusts the image light generated by the image-light generating unit by replacing at least a part of the image data to be transmitted with dummy data indicating black.

10. The head-mounted display device according to claim 2, wherein

the image-light generating unit includes:

a display device that generates the image; and

a light source that emits image light representing the generated image, and

when it is determined that the user faces the operation surface, the control unit adjusts the image light generated by the image-light generating unit by reducing a liquid crystal aperture ratio of at least a part of the display device.

11. The head-mounted display device according to claim 1, further comprising a detecting unit that acquires change information indicating a change in a direction of the image display unit and detects, using the change information, movement of a head exceeding a fixed amount of the user wearing the image display unit, wherein

when the movement of the head exceeding the fixed amount is detected, the control unit adjusts the luminance of the image-light generating unit or adjusts the image light generated by the image-light generating unit to reduce the visibility of the virtual image.

12. The head-mounted display device according to claim 11, wherein the detecting unit sets, according to occurrence of a trigger set in advance, an initial position, which is a position serving as a reference in detecting the movement of the image display unit, acquires the change information with respect to the initial position, and detects, using the change information, the movement of the head exceeding the fixed amount.

13. The head-mounted display device according to claim 12, wherein the detecting unit specifies the initial position and the change information according to a combination of an angle of the head corresponding to the movement of the head in a vertical direction of the user wearing the image display unit and a direction of a face of the user corresponding to movement of the face in a horizontal direction.

14. The head-mounted display device according to claim 11, wherein

the image display unit further includes an angular-velocity detecting unit that detects angular velocity of the image display unit, and

the detecting unit acquires the angular velocity detected as the change information and, when an angle calculated from the angular velocity exceeds a first threshold set in advance and the angular velocity exceeds a second threshold set in advance, the detecting unit determines that the movement of the head exceeding the fixed amount is detected.

15. The head-mounted display device according to claim 11, wherein

the image display unit further includes an acceleration detecting unit that detects acceleration of the image display unit, and

the detecting unit further acquires the detected acceleration as the change information and determines, using the acceleration and a tilt of the image display unit calculated from the acceleration, whether the movement of the head exceeding the fixed amount is detected.

16. The head-mounted display device according to claim 11, wherein

the image display unit further includes:

a terrestrial-magnetism detecting unit that detects a direction of the image display unit using terrestrial magnetism; and

an acceleration detecting unit that detects acceleration of the image display unit, and

the detecting unit acquires the detected direction and the detected acceleration as the change information and, when an angle calculated from the direction exceeds a first threshold set in advance and the acceleration exceeds a second threshold set in advance, the detecting unit determines that the movement of the head exceeding the fixed amount is detected.

17. The head-mounted display device according to claim 11, wherein the trigger set in advance is at least any one of power-on of the head-mounted display device, detection of startup of a predetermined application, and detection of pressing of a predetermined button.

18. A control method for a head-mounted display device including a control unit, the control unit including an operation surface, and the head-mounted display device further including an image display unit, the image display unit including an image-light generating unit, the control method comprising:

(a) causing, using the image-light generating unit that generates image light representing an image and emits the image light and a light guide unit that guides the emitted image light to an eye of a user, the user to visually recognize a virtual image and an external image that is external to the head-mounted display device;

(b) controlling image display in (a);

(c) determining whether the user faces the operation surface in order for (b); and

(d) adjusting, responsive to an indication that the user faces the operation surface in order for (b), luminance of the image-light generating unit or adjusting the image light generated by the image-light generating unit to reduce visibility of the virtual image while maintaining visibility of the external image;

(e) detecting contact with the control unit; and

(f) when the contact with the control unit is detected, causing a head-side light emitting unit to emit invisible light, the head-side light emitting unit being arranged in the image display unit, and causing a control-unit-side light emitting unit to emit invisible light, the control-unit-side light emitting unit being arranged in the operation surface.

19. A control method for a head-mounted display device including a control unit, the control unit including an operation surface, and the head-mounted display device further including an image display unit, the image display unit including an image-light generating unit, the control method comprising:

(a) causing, using an image-light generating unit that generates image light representing an image and emits the image light and a light guide unit that guides the emitted image light to an eye of a user, the user to visually recognize a virtual image and an external image that is external to the head-mounted display device;

(b) controlling image display in (a);

(c) acquiring change information indicating a change in a direction of the head-mounted display device and detecting, using the change information, movement of a head exceeding a fixed amount of the user wearing the head-mounted display device;

(d) adjusting, when the movement of the head exceeding the fixed amount is detected, luminance of the image-light generating unit or adjusting the image light generated by the image-light generating unit to reduce visibility of the virtual image while maintaining visibility of the external image;

(e) detecting contact with the control unit; and

(f) when the contact with the control unit is detected, causing a head-side light emitting unit to emit invisible light, the head-side light emitting unit being arranged in the image display unit, and causing a control-unit-side light emitting unit to emit invisible light, the control-unit-side light emitting unit being arranged in the operation surface.