Head-mounted display device and control method of head-mounted display device

1. A head-mounted display device that enables a user to visually recognize a virtual image and an external scene, comprising:

a pair of display drive units that generates and emits image light representing an image; and

an image processing unit that controls the display drive units so as to emit the image light from emission areas of the display drive units,

wherein the image processing unit controls the pair of display drive units so as to move the emission areas in any one of a first direction in which an image formed by the image light emitted from one of the display drive units and an image formed by the image light emitted from the other of the display drive units move close to each other in cooperation and a second direction in which an image formed by the image light emitted from one of the display drive units and an image formed by the image light emitted from the other of the display drive units move apart from each other in cooperation to change a focal distance of an image in a virtual image which is visually recognized by the user,

wherein the emission areas are areas through which image light is actually emitted than a reference area through which the respective display drive unit emits image light in a normal state, the emission areas being larger than respective ones of the images formed by the respective display drive units.

2. The head-mounted display device according to claim 1 , wherein the image processing unit controls the pair of display drive units so as to move the emission areas in the first direction to change the focal distance of the image in the virtual image which is visually recognized by the user.

3. The head-mounted display device according to claim 1 , wherein the image processing unit controls the pair of display drive units so as to move the emission areas in the first direction to change the focal distance of the image in the virtual image which is visually recognized by the user.

4. The head-mounted display device according to claim 3 , further comprising a distance measuring unit that measures a distance from the user to an object present in front of the user's eyes,

wherein the image processing unit acquires the measured distance as the target value.

5. The head-mounted display device according to claim 3 , wherein the image processing unit controls the pair of display drive units so as to set the emission area of the one display drive unit to a right end of the reference area and to set the emission area of the other display drive unit to a left end of the reference area to set the focal distance of the image in the virtual image which is visually recognized by the user to infinity.

6. The head-mounted display device according to claim 3 , wherein the image processing unit controls the pair of display drive units so as to set a size of the emission area to the same size of the reference area and to set the emission areas of the pair of display drive units to the center of the reference area to set the focal distance of the image in the virtual image which is visually recognized by the user to infinity.

7. The head-mounted display device according to claim 1 , wherein the image processing unit

acquires a target value of the focal distance,

calculates a degree of movement of the emission areas from the acquired target value, and

moves the emission area of the one display drive unit and the emission area of the other display drive unit on the basis of the calculated degree of movement.

8. The head-mounted display device according to claim 7 , further comprising a sight line detecting unit that detects a direction of the user's sight line,

wherein the distance measuring unit measures a distance to the object present in the direction of the detected sight line.

9. The head-mounted display device according to claim 1 , further comprising a marker detecting unit that detects a predetermined marker present in front of the user's eyes,

wherein the image processing unit changes the focal distance of the image when the predetermined marker is detected.

10. The head-mounted display device according to claim 9 , wherein the predetermined marker is installed on an article external with respect to the head-mounted display device.

11. A control method of a head-mounted display device that includes a pair of display drive units generating and emitting image light representing an image and that enables a user to visually recognize a virtual image and an external scene, comprising:

(a) controlling the pair of display drive units so as to emit the image light from emission areas of the display drive units,

wherein the controlling (a) includes controlling the pair of display drive units so as to move the emission areas in any one of a first direction in which an image formed by the image light emitted from one of the display drive units and an image formed by the image light emitted from the other of the display drive units move close to each other in cooperation and a second direction in which an image formed by the image light emitted from one of the display drive units and an image formed by the image light emitted from the other of the display drive units move apart from each other in cooperation to change a focal distance of an image in a virtual image which is visually recognized by the user, and

wherein the emission areas are areas through which image light is actually emitted from respective display drive units, the emission areas being smaller in a horizontal direction than a reference area through which the respective display drive unit emits image light in a normal state, the emission areas being larger than respective ones of the images formed by the respective display units.