JP2016092508A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device which is balanced in weight and is hardly inclined.SOLUTION: The image display device includes a light source part 43 which emits laser light, a drawing part 35 which reflects the laser light to a mirror and rotates the mirror, to perform drawing, a half mirror 3 which reflects the laser light, to form a virtual image, a moving part which interlockingly moves the drawing part 35 and the half mirror 3, an imaging apparatus 12 which detects the line-of-sight of an observer 8 observing the virtual image, and a control part 17 which controls the moving part according to the movement of the line-of-sight. The half mirror 3 includes a right mirror 3a which displays the virtual image for the right eye of the observer 8 and a left mirror 3b which displays the virtual image for the left eye of the observer 8. The moving part includes a mirror moving part 9 which moves the right mirror 3a and the left mirror 3b and the centroid of the mirror moving part 9 is located between the right mirror 3a and the left mirror 3b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image display device.

  An image display device that displays an image by scanning light on the retina of an observer has been studied. This image display device is used for a head-mounted display or a head-up display. Since this image display apparatus can simplify the configuration for generating an image, the apparatus can be reduced in size and weight.

  An image display device that displays a color image on the retina of an observer includes a light source that emits red, blue, and green laser beams. And the laser beam which the light source inject | emitted irradiates the mirror in a drawing part. The drawing unit swings the mirror and controls the direction of travel of the laser light for drawing. The laser beam output from the drawing unit irradiates the hologram mirror. Interference fringes are formed on the hologram mirror, and the hologram mirror changes the traveling direction of the laser light toward the observer's pupil.

  An image display device that moves a display unit in accordance with the movement of an observer's line of sight is disclosed in Patent Document 1. According to this, in the image display device, the detection unit detects the position of the pupil and moves the display unit in accordance with the movement of the pupil. The image display device includes an optical system that guides light from the display unit toward the pupil and light from the pupil toward the detection unit. And the moving part which moves this optical system and a display part was installed.

JP 2002-328330 A

  In Patent Document 1, the optical system for the right eye and the display unit are integrated, and the optical system for the left eye and the display unit are integrated. Then, the optical system for the right eye and the optical system for the left eye are connected, and one moving unit moves the optical system for the right eye and the optical system for the left eye. And the moving part was installed in the right side of the optical system for right eyes.

  Since the moving unit generates a force for moving the optical system and the display unit, the moving unit is a heavy part. When the heavy moving unit is on the right side of the right eye, the weight balance cannot be achieved, and the right side of the image display device tends to tilt downward. Therefore, an image display device that balances the weight and is difficult to tilt has been demanded.

  The present invention has been made to solve the above-described problems, and can be realized as the following forms or application examples.

[Application Example 1]
An image display device according to this application example, wherein a light source unit that emits laser light, a drawing unit that draws the laser beam by reflecting the laser beam on a mirror, and a virtual image by reflecting the laser beam A display unit that forms an image, a moving unit that moves in conjunction with the drawing unit and the display unit, a line-of-sight detection unit that detects the line of sight of an observer who observes the virtual image, and the movement according to the movement of the line of sight A control unit that controls a moving unit, wherein the display unit displays a first display unit that displays the virtual image for the right eye of the observer, and a first unit that displays the virtual image for the left eye of the observer. Two display units, and the moving unit includes a first moving unit that moves the first display unit and the second display unit, and the center of gravity of the first moving unit is the first display unit and the first display unit It is located between the second display section.

  According to this application example, the light source unit emits laser light. The emitted laser light is reflected by the mirror of the drawing unit and irradiates the display unit. The drawing unit rotates the mirror to draw on the display unit, and the display unit forms a virtual image. When the observer observing the virtual image moves his / her line of sight, the line-of-sight detection unit detects the line of sight of the observer. Then, the control unit controls the moving unit according to the movement of the line of sight, and the moving unit moves in conjunction with the drawing unit and the display unit. Accordingly, the image display apparatus moves the virtual image in accordance with the movement of the observer's line of sight. The image display device can project a virtual image so that the laser light passes through the pupil of the observer.

  The display unit includes a first display unit that displays a virtual image for the right eye of the observer and a second display unit that displays a virtual image for the left eye. At this time, the first display unit is located at a location facing the viewer's right eye, and the second display unit is located at a location facing the viewer's left eye. And the gravity center of the 1st moving part which moves the 1st display part and the 2nd display part is located between the 1st display part and the 2nd display part.

  Since the first moving part is a part that generates a force to move the display part, it is a heavy part. When the center of gravity of the heavy first moving unit is on the right side or the left side of the eye, the weight balance cannot be balanced, and the image display apparatus is easily tilted. Compared to this structure, in the structure of this application example, the center of gravity of the first moving unit is located between the first display unit and the second display unit, so that the image display device can be made difficult to tilt.

[Application Example 2]
In the image display device according to the application example, the moving unit includes a connecting unit that connects the drawing unit and the display unit.

  According to this application example, the connecting unit connects the drawing unit and the display unit. When the first moving unit moves the display unit, the drawing unit moves in conjunction with the display unit. Therefore, the moving unit can move the display unit and the drawing unit in conjunction with each other. And the number of moving parts can be reduced compared with the case where the moving part which moves a display part and the moving part which moves a drawing part are provided. As a result, since the moving part can be reduced, a structure that can be easily manufactured can be obtained.

[Application Example 3]
In the image display device according to the application example, the moving unit includes a second moving unit that moves the drawing unit.

  According to this application example, the first moving unit moves the display unit, and the second moving unit moves the drawing unit. The first moving part and the second moving part are parts that generate force and are heavy parts. At this time, since the moving parts are dispersed in a plurality of locations, heavy parts can be dispersed and arranged. Accordingly, the image display device can be easily supported.

[Application Example 4]
In the image display device according to the application example described above, the first moving unit moves the first display unit and the second display unit with one driving source.

  According to this application example, the first moving unit moves the first display unit and the second display unit with one drive source. When a drive source for driving the first display unit and a drive source for driving the second display unit are provided, there are two drive sources. Compared to this case, the number of drive sources can be reduced in this application example. As a result, it is possible to make the structure easy to manufacture with a small number of drive sources.

1 is a schematic perspective view showing a configuration of a head mounted display according to a first embodiment. (A) is a principal part schematic sectional side view which shows the structure of a drawing apparatus and a half mirror, (b) is a principal part schematic top view which shows the structure of a drawing apparatus and a half mirror. (A) is a principal part schematic upper cross-sectional view which shows the structure of a mirror protection part and a half mirror, (b) is a principal part schematic plane sectional view which shows the structure of a mirror moving part. The block diagram which shows the structure of a drawing apparatus. The top view which shows the optical scanning part which a drawing part has. The side sectional view of an optical scanning part. The block diagram of a voltage application part. The figure for demonstrating the voltage which a voltage generation part generate | occur | produces. The electric control block diagram of a head mounted display. The flowchart which shows the drawing method. The schematic diagram for demonstrating the drawing method. The schematic diagram for demonstrating the drawing method. The schematic perspective view which shows the structure of the head mounted display concerning 2nd Embodiment. The principal part schematic upper cross section which shows the structure of the head mounted display in connection with 3rd Embodiment. The principal part schematic upper cross section which shows the structure of the head mounted display in connection with 4th Embodiment.

In the present embodiment, an embodiment of a head mounted display having a characteristic structure will be described with reference to the drawings. In addition, each member in each drawing is illustrated with a different scale for each member in order to make the size recognizable on each drawing.
(First embodiment)
A head mounted display according to the first embodiment will be described with reference to FIGS. FIG. 1 is a schematic perspective view showing a configuration of a head mounted display. As shown in FIG. 1, a head-mounted display 1 as an image display device has a shape similar to glasses, and is used by being mounted on a human head 2.

  The head mounted display 1 includes a half mirror 3 as a pair of display units and a half mirror frame 4 that supports the half mirror 3. The half mirror 3 has a substantially rectangular plate shape with a concave surface, and is disposed at a location facing the eye of the human head 2. Of the half mirrors 3, the half mirror 3 at a location facing the right eye is a right mirror 3a as a first display unit, and the half mirror 3 at a location facing the left eye is a left mirror 3b as a second display unit. The half mirror 3 is installed in the mirror protector 5, and the half mirror frame 4 surrounds the mirror protector 5 and supports the mirror protector 5. The half mirror frame 4 between the half mirrors 3 is provided with a nose pad 6 that protrudes toward the human head 2, and the nose pad 6 is disposed so as to contact the nose 2 a of the human head 2. The nose pad 6 has a function of abutting and fixing the head mounted display 1 to the human head 2.

  A direction passing through the nose 2a and the back of the human head 2 is defined as a front-rear direction 7a. A direction orthogonal to the front-rear direction 7a is defined as a left-right direction 7b. The left-right direction 7b is a direction in which the right eye and the left eye in the human head 2 are aligned. A direction orthogonal to the front-rear direction 7a and the left-right direction 7b is defined as a vertical direction 7c. When the human head 2 is the head of the observer 8, the vertical direction 7 c is a direction passing through the legs of the observer 8 and the human head 2 while the observer 8 is standing.

  A mirror moving unit 9 as a moving unit and a first moving unit is installed on the upper side in the figure in the vertical direction 7 c of the half mirror frame 4. The mirror moving portion 9 includes a screw rod 9b extending in the left-right direction 7b and a screw rod rotating portion 9a for rotating the screw rod 9b. Bearings 9d are installed at both ends of the screw rod 9b, and the screw rod 9b can rotate stably. Two female screw portions 9c are movably installed between the screw rod rotating portion 9a and the bearing 9d, and the female screw portion 9c is fixed to the half mirror 3.

  A male screw is formed on the outer periphery of the screw rod 9b. The female screw portion 9c is provided with a hole in which a female screw is formed, and the female screw portion 9c is screwed to the screw rod 9b. Then, the screw rod rotating portion 9a rotates the screw rod 9b. When the screw rod 9b rotates, the female screw portion 9c moves in the left-right direction 7b. Since the female screw portion 9c is fixed to the half mirror 3, when the female screw portion 9c moves, the half mirror 3 also moves. The mirror moving unit 9 is a linear motion mechanism that moves the half mirror 3 in the left-right direction 7b. Although the movement amount of the half mirror 3 is not particularly limited, in this embodiment, for example, it is about 1 cm.

  The mirror moving part 9 has a symmetrical shape, and the place where the screw rod rotating part 9 a is located is the center of gravity of the mirror moving part 9. The center of gravity of the mirror moving unit 9 is located between the right mirror 3a and the left mirror 3b. When viewed from the front-rear direction 7a, the center of gravity of the mirror moving unit 9 is located at the center of the half mirror frame 4, so the head mounted display 1 is a device that is difficult to tilt. Therefore, the head mounted display 1 can be attached to the human head 2 in a stable state.

  The half mirror frame 4 includes a substantially rectangular parallelepiped drawing device 10 on both ends. The drawing device 10 is installed on the opposite side of the nose pad 6 with respect to the half mirror 3. One drawing apparatus 10 is installed for one half mirror 3. The half mirror frame 4 is provided with two half mirrors 3 and two drawing devices 10. The drawing device 10 on the right side in the drawing is a right drawing device 10a, and the drawing device 10 on the left side in the drawing is a left drawing device 10b.

  The half mirror frame 4 is provided with a guide 11 for guiding the drawing device 10 so as to be movable in the front-rear direction 7 a of the human head 2. The right guide 11 in the figure is a right guide 11a, and the left guide 11 in the figure is a left guide 11b. The right guide 11a guides the right drawing device 10a, and the left guide 11b guides the left drawing device 10b.

  An imaging device 12 is installed between the mirror protection unit 5 and the drawing device 10 in the half mirror frame 4. The imaging device 12 photographs the eye of the human head 2. Two imaging devices 12 are installed in the half mirror frame 4. The imaging device 12 installed on the right side of the half mirror frame 4 is called a right imaging device 12a, and the imaging device 12 installed on the left side of the half mirror frame 4 is called a left imaging device 12b. The right imaging device 12a captures the right eye, and the left imaging device 12b captures the left eye.

  The imaging device 12 can be a solid-state imaging device such as a CCD image sensor (Charge Coupled Device) or a CMOS image sensor (Complementary Metal Oxide Semiconductor), and an electron tube imaging device. In the present embodiment, for example, a CMOS image sensor is used for the imaging device 12.

  A vine portion 13 extending from both ends of the half mirror frame 4 toward the ear 2b of the human head 2 is installed. The vine portion 13 is used by being sandwiched between the ears 2b like glasses. A hinge 14 is installed between the vine portion 13 and the half mirror frame 4, and the vine portion 13 is rotatable about the hinge 14. The head mount display 1 can be easily accommodated by bending the vine portion 13 with respect to the half mirror frame 4. In addition, the shape of the half mirror 3, the half mirror frame 4, the mirror protection part 5, and the vine part 13 is not limited to the shape shown to a figure, It can be made into various shapes.

  The head mounted display 1 is installed on the human head 2 at three points, ie, left and right vine portions 13 and a nose pad 6. These three points are symmetrical with respect to the front-rear direction 7 a passing through the nose pad 6. Since the center of gravity of the heavy mirror moving portion 9 is located in the vertical direction 7 c of the nose pad 6, the weight distribution of the head mounted display 1 is symmetrical with respect to the front-rear direction 7 a passing through the nose pad 6. ing. For this reason, the head mounted display 1 can be stably installed on the human body head 2.

  A connector 15 is installed at a position on the left vine portion 13 on the occipital side of the human head 2, and a wiring 16 is connected to the connector 15. A controller 17 is connected to the wiring 16. The control unit 17 is a device that controls the mirror moving unit 9, the drawing device 10, and the imaging device 12. A video signal output device 21 is connected to the control unit 17 via a wiring 18.

  The video signal output device 21 is a device that outputs a stereo video signal to the control unit 17. The video signal output device 21 is, for example, a portable information terminal such as a blue disc player, a personal computer, or a smartphone. The controller 17 receives the video signal and separates it into red, blue, and green luminance signals. Further, the control unit 17 extracts a scanning signal of a vertical scanning signal and a horizontal scanning signal from the video signal. The control unit 17 outputs a scanning signal of a vertical scanning signal and a horizontal scanning signal to the drawing apparatus 10 via the wiring 16. Furthermore, the light source unit 43 is installed in the drawing apparatus 10, and the control unit 17 outputs red, blue, and green luminance signals to the light source unit 43.

  FIG. 2A is a schematic cross-sectional side view of a main part showing the structures of the drawing apparatus and the half mirror. FIG. 2B is a schematic top view of the main part showing the structures of the drawing apparatus and the half mirror. FIG. 3A is a schematic top cross-sectional view of the relevant part showing the structure of the mirror protection part and the half mirror. FIG. 3B is a schematic plan cross-sectional view of the main part showing the structure of the mirror moving part. FIG. 2A to FIG. 3B show the right side of the head mounted display 1. The head mounted display 1 is substantially symmetrical, and the left side of the head mounted display 1 has the same shape as the right side. As shown in FIGS. 2A and 2B, the drawing apparatus 10 emits laser light 22 toward the half mirror 3. The emitted laser beam 22 is reflected by the half mirror 3 and irradiates the eyeball 2 c of the human head 2. The drawing device 10 and the half mirror 3 form a virtual image corresponding to the video signal, and the observer 8 can view the video by viewing the virtual image.

  The half mirror 3 and the drawing apparatus 10 are connected by a connecting part 24 as a moving part. The connecting portion 24 is formed of a flexible material, and a metal, resin, or the like can be used as the material of the connecting portion 24. When a metal is used for the material of the connecting portion 24, it is preferable to make it thin as long as it does not buckle. The stress required to deform the connecting portion 24 can be reduced, and fatigue failure of the connecting portion 24 can be suppressed. As shown in FIG. 3A, a cavity 25 extending in the left-right direction 7 b is installed inside the mirror protection unit 5, and the half mirror 3 is installed in the cavity 25. The mirror protection part 5 is provided with a first window part 5a as a window part and a second window part 5b as a window part with a cavity 25 in between. The 1st window part 5a and the 2nd window part 5b are formed with the light-transmissive plate-shaped member.

  The half mirror 3 is translucent. And the 1st window part 5a and the 2nd window part 5b are installed on both sides of the half mirror 3. As shown in FIG. Accordingly, part of the light 26 that passes through the second window portion 5b passes through the half mirror 3 and further passes through the first window portion 5a. Therefore, the observer 8 can receive the light 26 that passes through the first window portion 5a, the half mirror 3, and the second window portion 5b. As a result, the observer 8 can receive the light 26 and the laser light 22 transmitted through the mirror protection unit 5.

  The first window 5 a is located on the human head 2 side with respect to the cavity 25, and the second window 5 b is located on the opposite side of the first window 5 a with respect to the cavity 25. The observer 8 is prevented from coming into contact with the half mirror 3 by the first window portion 5a and the second window portion 5b. Thereby, it can prevent that the observer 8 contacts and rubs the moving half mirror 3. FIG. Further, it is possible to prevent the half mirror 3 from being contaminated by dust or dirt.

  The half mirror 3 includes a plate-like member 3c, and a concave surface 3d is provided on the surface of the plate-like member 3c facing the human head 2. A hologram sheet 27 is installed on the concave surface 3d. The hologram sheet 27 diffracts the laser beam 22 and changes the traveling direction of the laser beam 22. Therefore, the concave surface 3d of the half mirror 3 can be made shallow. Even when the laser beam 22 hits the hologram sheet 27, the heat of the hologram sheet 27 can be conducted to the plate-like member 3 c of the half mirror 3 to suppress the temperature rise of the hologram sheet 27. The plate-like member 3c is glass and has heat resistance. Therefore, it is possible to suppress the deformation of the plate-like member 3c even when the laser beam 22 is irradiated.

  The half mirror 3 is movable in the left-right direction 7b along the first window portion 5a and the second window portion 5b in the cavity 25. The half mirror 3 is connected to the drawing apparatus 10 by a connecting portion 24. When the mirror moving unit 9 moves the half mirror 3, the drawing apparatus 10 works with the half mirror 3. Accordingly, the mirror moving unit 9 moves the half mirror 3 and the drawing apparatus 10 in conjunction with each other.

  Next, the mirror moving unit 9 will be described. As shown in FIG. 3B, a motor 28 as a drive source is installed in the screw rod rotating portion 9a. A first gear 29 is installed on the rotating shaft of the motor 28, and a second gear 30 is installed on the screw rod 9b. The first gear 29 and the second gear 30 mesh with each other, and the torque of the motor 28 is transmitted to the screw rod 9b. Near the second gear 30 is installed a bearing 31 that rotatably supports the threaded rod 9b. The bearing 31 supports the screw rod 9b so that the torque of the motor 28 is reliably transmitted to the screw rod 9b.

  The screw rod 9b on the right side of the screw rod rotating portion 9a and the screw rod 9b on the left side of the drawing have the same winding direction and are provided with the same pitch. Thereby, the right mirror 3a and the left mirror 3b move in the same direction in the left-right direction 7b. The amount of movement of the right mirror 3a and the amount of movement of the left mirror 3b are the same. The mirror moving portion 9 has a symmetrical shape, and the center of gravity of the mirror moving portion 9 is located at a position where the screw rod rotating portion 9a is located.

  The mirror moving unit 9 moves the right mirror 3 a and the left mirror 3 b with one motor 28. When a motor for driving the right mirror 3a and a motor for driving the left mirror 3b are provided, there are two motors. Compared to this case, the number of motors can be reduced, so that the mirror moving unit 9 can be easily manufactured.

  The motor 28 only needs to be able to control the rotation angle, and the motor type is not particularly limited. As the motor 28, a stepping motor, a DC servo motor, or an AC servo motor can be used. In addition, a portion constituted by the screw rod rotating portion 9a, the screw rod 9b, and the female screw portion 9c may be a linear motor. A linear motor can be used as a linear motion mechanism that moves the half mirror 3 along a straight line.

  Next, the drawing apparatus 10 will be described. FIG. 4 is a block diagram showing the configuration of the drawing apparatus. As shown in FIG. 4, for convenience of explanation, the X axis, the Y axis, and the Z axis are illustrated as three axes orthogonal to each other, and the tip side of the illustrated arrow is “+ side” and the base end side is “ -Side ". A direction parallel to the X axis is referred to as an “X axis direction”, a direction parallel to the Y axis is referred to as a “Y axis direction”, and a direction parallel to the Z axis is referred to as a “Z axis direction”. A plane parallel to both the X axis and the Y axis is referred to as an “XY plane”.

  The drawing apparatus 10 includes a light source unit 32 that emits laser light 22. The laser light 22 emitted from the light source unit 32 is output to the prism 33. The prism 33 tilts the optical axis of the laser beam 22 and deforms the cross-sectional shape. The prism 33 is provided with a detection unit 34 that detects the intensity of the laser beam 22. The laser beam 22 that has passed through the prism 33 is output to the drawing unit 35. The drawing unit 35 scans the laser beam 22. The drawing apparatus 10 includes a drawing control unit 36, and the drawing control unit 36 controls operations of the light source unit 32 and the drawing unit 35. Each member constituting the drawing apparatus 10 is housed in a housing 37.

  The light source unit 32 includes a red light source 38r, a blue light source 38b, and a green light source 38g. The red light source 38r, the blue light source 38b, and the green light source 38g emit red laser light 22r, blue laser light 22b, and green laser light 22g, respectively.

  A red lens 41r, a blue lens 41b, and a green lens 41g are provided on the optical axes of the red light source 38r, the blue light source 38b, and the green light source 38g, respectively. The red lens 41r, the blue lens 41b, and the green lens 41g are collimator lenses, and make the red laser light 22r, the blue laser light 22b, and the green laser light 22g into parallel rays or substantially parallel rays, respectively. A red mirror 42r, a blue mirror 42b, and a green mirror 42g are provided on the optical axes of the red lens 41r, the blue lens 41b, and the green lens 41g, respectively. The blue mirror 42b and the green mirror 42g are dichroic mirrors.

  As the red light source 38r, the blue light source 38b, and the green light source 38g, for example, a semiconductor laser such as an edge emitting semiconductor laser or a surface emitting semiconductor laser can be used. By using a semiconductor laser, the red light source 38r, the blue light source 38b, and the green light source 38g can be reduced in size.

  The light combining unit 42 is configured by the red mirror 42r, the blue mirror 42b, and the green mirror 42g. The red mirror 42r reflects the red laser light 22r. The blue mirror 42b reflects the blue laser light 22b and transmits the red laser light 22r. The green mirror 42g has characteristics of transmitting the green laser light 22g and reflecting the red laser light 22r and the blue laser light 22b. By the red mirror 42r, the blue mirror 42b, and the green mirror 42g, the red laser light 22r, the blue laser light 22b, and the green laser light 22g are synthesized so that the optical axes thereof coincide or substantially coincide with each other. Injected in the + X-axis direction.

  The prism 33 has a first function for tilting the optical axis of the laser light 22, a second function for deforming the cross-sectional shape of the laser light 22, and a third function for controlling the radiation angle of the laser light 22. The prism 33 is a substantially colorless and transparent polyhedron made of glass or quartz. Such a prism 33 is not particularly limited as long as it has the above function, and for example, a triangular prism having a substantially triangular prism shape can be used.

  The prism 33 shapes the shape of the cross section perpendicular to the optical axis of the laser light 22 from a substantially elliptical shape to a substantially circular shape. Specifically, the prism 33 substantially reduces the cross-sectional shape of the laser light 22 by increasing the width in the XY plane direction while keeping the width in the Z-axis direction of the cross-sectional shape of the incident laser light 22 substantially constant. Shape it into a circle. In other words, the prism 33 increases the length of the short axis of the ellipse, which is a cross-sectional shape, and shapes the cross-sectional shape of the laser beam 22 so that the ratio of the short axis to the long axis (aspect ratio) is approximately 1. Thus, by making the cross-sectional shape of the laser beam 22 substantially circular, the drawing apparatus 10 can exhibit excellent image display characteristics.

  The exit surface 33a of the prism 33 is a curved convex surface, functions as a condensing lens, and condenses the laser light 22 incident on the prism 33 as parallel light. By condensing the laser beam 22 in this way, a clearer and higher resolution image can be displayed.

  A detection unit 34 is installed at one end of the prism 33. The incident surface 33b of the prism 33 is configured to slightly reflect the laser light 22 (for example, a reflectance of about 0.1%), and the detection unit 34 is located on the optical path of the reflected light. The detection unit 34 has a function of detecting the intensity of the laser light 22. Such a detector 34 has a light receiving element such as a photodiode. The light receiving element outputs a signal (voltage) having a magnitude corresponding to the light intensity of the received reflected light, and based on this signal, each light intensity of the red laser light 22r, the blue laser light 22b, and the green laser light 22g. Can be detected. A portion from the red light source 38 r, the blue light source 38 b, and the green light source 38 g to the prism 33 is a light source unit 43.

  Information regarding the light intensities of the red laser beam 22r, the blue laser beam 22b, and the green laser beam 22g detected by the detection unit 34 is sent to the drawing control unit 36. The drawing control unit 36 controls driving of the red light source 38r, the blue light source 38b, and the green light source 38g based on the received information.

  The drawing unit 35 has a function of two-dimensionally scanning the laser light 22 that has passed through the prism 33. The drawing unit 35 is not particularly limited as long as the laser beam 22 can be two-dimensionally scanned. The drawing unit 35 has a light reflecting surface 44 as a mirror that reflects the laser light 22. A normal axis of the light reflecting surface 44 is defined as a first axis 44a, and two axes perpendicular to the tangential direction of the light reflecting surface 44 are defined as a second axis 44b and a third axis 44c. In the drawing unit 35, the light reflecting surface 44 swings around the second axis 44b and the third axis 44c. The drawing unit 35 draws the laser beam 22 by reflecting the laser beam 22 on the light reflecting surface 44 and rotating the light reflecting surface 44.

  The housing 37 is provided with a light transmissive window 45. The window portion 45 is made of a transparent member such as glass or plastic. The laser light 22 that is two-dimensionally scanned by the drawing unit 35 is emitted out of the housing 37 through the window 45.

  Next, the drawing unit 35 will be described. FIG. 5 is a plan view showing an optical scanning unit included in the drawing unit, and FIG. 6 is a side sectional view of the optical scanning unit. FIG. 7 is a block diagram of the voltage application unit. FIG. 8 is a diagram for explaining the voltage generated by the voltage generator.

  As shown in FIGS. 5 and 6, the drawing unit 35 includes a movable portion 46, a pair of shaft portions 47, and a shaft portion 48 (first shaft portion). Further, the drawing unit 35 includes a frame body 49, two pairs of shaft portions 50, a shaft portion 51, a shaft portion 52, a shaft portion 53 (second shaft portion), and a support portion 54. Further, the drawing unit 35 includes a permanent magnet 55, a coil 56, a magnetic core 57, and a voltage application unit 58.

  The movable portion 46, the pair of shaft portions 47, and the shaft portion 48 constitute a first vibration system that swings (reciprocates) around the second shaft 44b. The movable portion 46, the pair of shaft portions 47, the shaft portion 48, the frame body portion 49, the two pairs of shaft portions 50, the shaft portion 51, the shaft portion 52, the shaft portion 53, and the permanent magnet 55 are arranged around the third shaft 44c. A second vibration system that swings (reciprocates) is configured. The permanent magnet 55, the coil 56, and the voltage application unit 58 constitute a drive unit that drives the first vibration system and the second vibration system described above.

  The movable part 46 includes a base 61 and a light reflecting plate 62 fixed to the base 61. A light reflecting surface 44 having light reflectivity is provided on the upper surface of the light reflecting plate 62. The light reflecting surface 44 reflects the laser light 22. As described above, the movable portion 46 swings around the second shaft 44b and the third shaft 44c. That is, the base 61, the light reflecting plate 62, and the light reflecting surface 44 that constitute the movable portion 46 also swing around the second shaft 44b and the third shaft 44c.

  Further, the lower surface of the light reflecting plate 62 is fixed to the base 61 via a spacer 63. Accordingly, the light reflecting plate 62 is swung around the second shaft 44b while preventing the light reflecting plate 62 from contacting the shaft portion 47, the shaft portion 48, the frame body portion 49, and the shaft portions 50 to 53. be able to.

  The frame body portion 49 has a frame shape and is provided so as to surround the base portion 61 of the movable portion 46 described above. In other words, the base portion 61 of the movable portion 46 is provided inside the frame body portion 49 having a frame shape. The frame body portion 49 is supported by the support portion 54 via the shaft portion 50 to the shaft portion 53. The base portion 61 of the movable portion 46 is supported by the frame body portion 49 via the shaft portion 47 and the shaft portion 48.

  The shaft portion 47, the shaft portion 48, and the shaft portion 50 to the shaft portion 53 can be elastically deformed. The shaft portion 47 and the shaft portion 48 connect the movable portion 46 and the frame body portion 49 so that the movable portion 46 can swing around the second shaft 44b. In addition, the shaft portion 50 to the shaft portion 53 connect the frame body portion 49 and the support portion 54 so that the frame body portion 49 can swing around the third shaft 44c orthogonal to the second shaft 44b. .

  The shaft portion 47 and the shaft portion 48 are disposed at locations facing each other through the base portion 61 of the movable portion 46. The shaft portion 47 and the shaft portion 48 each have a longitudinal shape extending in the direction along the second shaft 44b. Each of the shaft portion 47 and the shaft portion 48 has one end connected to the base 61 and the other end connected to the frame body 49. Further, the shaft portion 47 and the shaft portion 48 are arranged so that the center axis thereof coincides with the second shaft 44b. Each of the shaft portion 47 and the shaft portion 48 is torsionally deformed with the swing around the second shaft 44b.

  The shaft portion 50 to the shaft portion 53 are disposed at locations facing each other with the frame body portion 49 interposed therebetween. Further, the shaft portion 50 to the shaft portion 53 each have a longitudinal shape extending in the direction along the third shaft 44c. Each of the shaft portions 50 to 53 has one end portion connected to the frame body portion 49 and the other end portion connected to the support portion 54. The shaft portion 50 and the shaft portion 51 are disposed so as to face each other via the third shaft 44c. Similarly, the shaft portion 52 and the shaft portion 53 are faced to each other via the third shaft 44c. Has been placed. In such a shaft portion 50 to the shaft portion 53, the pair of the shaft portion 50 and the shaft portion 51 and the pair of the shaft portion 52 and the shaft portion 53 are respectively associated with the swing of the frame body portion 49 around the third shaft 44c. Twist and deform.

  As described above, the movable portion 46 can be swung around the second shaft 44b, and the frame body portion 49 can be swung around the third shaft 44c. The shaft 44b and the third shaft 44c can be swung around two axes.

  A permanent magnet 55 is joined to the lower surface of the frame body portion 49. The permanent magnet 55 is magnetized in a direction inclined with respect to the second shaft 44b and the third shaft 44c in plan view. The permanent magnet 55 has a longitudinal shape (bar shape) extending in a direction inclined with respect to both the second shaft 44b and the third shaft 44c. The permanent magnet 55 is magnetized in the longitudinal direction. That is, the permanent magnet 55 is magnetized so that one end is an S pole and the other end is an N pole. Further, the permanent magnet 55 is provided so as to be symmetric with respect to the intersection of the second shaft 44b and the third shaft 44c in plan view.

  The inclination angle θ in the magnetization direction (extending direction) of the permanent magnet 55 with respect to the third axis 44c is preferably 30 ° or more and 60 ° or less. By providing the permanent magnet 55 in this manner, the movable portion 46 can be swung around the third shaft 44c smoothly and reliably. As the permanent magnet 55, for example, a neodymium magnet, a ferrite magnet, a samarium cobalt magnet, an alnico magnet, a bond magnet, or the like can be suitably used. The permanent magnet 55 is obtained by magnetizing a hard magnetic material.

  A coil 56 is provided immediately below the permanent magnet 55. Thereby, the magnetic field generated from the coil 56 can be efficiently applied to the permanent magnet 55. The coil 56 is provided by being wound around a magnetic core 57. Thereby, the magnetic field generated by the coil 56 can be efficiently applied to the permanent magnet 55. The coil 56 is electrically connected to the voltage application unit 58. Then, when a voltage is applied to the coil 56 by the voltage application unit 58, a magnetic field having a magnetic flux orthogonal to the second axis 44b and the third axis 44c is generated from the coil 56.

  As shown in FIG. 7, the voltage applying unit 58 includes a first voltage generating unit 64 that generates a first voltage for rotating the movable unit 46 around the second axis 44b, and the movable unit 46 on the third axis. A voltage superimposing unit 66 that superimposes the first voltage and the second voltage, and a voltage superimposing unit 66 that superimposes the first voltage and the second voltage. The superimposed voltage is applied to the coil 56.

  The voltage superimposing unit 66 includes an adder 67 for applying a voltage to the coil 56. The adder 67 receives the first voltage from the first voltage generator 64 and the second voltage from the second voltage generator 65, and superimposes these voltages and applies them to the coil 56. ing.

  In FIG. 8A, the vertical axis indicates the first voltage, and the upper side in the figure is higher than the lower side. The horizontal axis shows the transition of time. A first voltage waveform 68 shows a voltage waveform output from the first voltage generator 64. As indicated by the first voltage waveform 68, the first voltage generator 64 generates a first voltage (main scanning voltage) that periodically changes in the first period 69. The first voltage waveform 68 has a waveform like a sine wave. The frequency of the first voltage is preferably 10 to 40 kHz, for example. The frequency of the first voltage is set to be equal to the torsional resonance frequency of the first vibration system including the movable portion 46, the pair of shaft portions 47, and the shaft portion 48. Thereby, the rotation angle around the second shaft 44b of the movable portion 46 can be increased.

  In FIG. 8B, the vertical axis indicates the second voltage, and the upper side in the figure is higher than the lower side. The horizontal axis shows the transition of time. A second voltage waveform 70 shows a voltage waveform output from the second voltage generator 65. As indicated by the second voltage waveform 70, the second voltage generator 65 generates a second voltage (sub-scanning voltage) that periodically changes in a second period 71 different from the first period 69. The second voltage waveform 70 has a sawtooth waveform. The frequency of the 2nd voltage waveform 70 should just differ from the frequency of the 1st voltage waveform 68, for example, it is preferable that it is 30-80 Hz (about 60 Hz). In the present embodiment, the frequency of the second voltage waveform 70 includes the movable portion 46, the pair of shaft portions 47, the shaft portion 48, the frame body portion 49, the two pairs of shaft portions 50 to 53, and the permanent magnet 55. Further, the frequency is adjusted to be different from the torsional resonance frequency (resonance frequency) of the second vibration system.

  The frequency of the second voltage waveform 70 is preferably smaller than the frequency of the first voltage waveform 68. As a result, the movable portion 46 is swung around the second axis 44b at the frequency of the first voltage waveform 68 and is swung around the third axis 44c at the frequency of the second voltage waveform 70 more reliably and smoothly. be able to. The drawing control unit 36 drives the drawing unit 35 in addition to the control of the light source unit 43.

  FIG. 9 is an electric control block diagram of the head mounted display. In FIG. 9, the head mounted display 1 includes a control unit 17 that controls the operation of the head mounted display 1. And the control part 17 is provided with CPU72 (central processing unit) which performs various arithmetic processes as a processor, and the memory 73 which memorize | stores various information. The mirror moving unit driving device 74, the right imaging device 12 a and the left imaging device 12 b are connected to the CPU 72 via the input / output interface 75 and the data bus 76. Further, the right drawing device 10 a, the left drawing device 10 b, the input device 77, and the output device 78 are also connected to the CPU 72 via the input / output interface 75 and the data bus 76.

  The mirror moving unit driving device 74 is a device that drives the mirror moving unit 9. The mirror moving unit driving device 74 receives the instruction signal from the CPU 72, and drives and moves the mirror moving unit 9 to the instructed state. The mirror moving unit 9 is provided with a position detection device that detects the position of the female screw portion 9c. The mirror moving unit driving device 74 drives the position detecting device to detect the position of the female screw portion 9c. The half mirror 3 is connected to the female screw portion 9 c, and the half mirror 3 and the drawing device 10 are connected by a connecting portion 24. Therefore, the mirror moving unit driving device 74 can detect the positions of the half mirror 3 and the drawing device 10.

  The imaging devices 12 of the right imaging device 12a and the left imaging device 12b include an area sensor made of a solid-state imaging device or the like, and can convert an image captured by the area sensor into an electrical signal and output it. This solid-state image sensor outputs the luminance of light as a voltage signal by accumulating electric charge according to the luminance of the received light and the time of receiving light. The imaging device 12 receives the instruction signal from the CPU 72 and takes an image according to the instruction signal. Then, the captured image data is transmitted to the memory 73.

  The input device 77 includes a device that performs wired or wireless communication with the video signal output device 21 in addition to a power switch and an operation switch. Various data are input by these input devices 77 and stored in the memory 73.

  The output device 78 includes a liquid crystal display device, a speaker, a device that performs wired or wireless communication with the video signal output device 21, and the like. Thereby, the control unit 17 can display and output the state of the head mounted display 1 and the setting state set by the observer 8.

  The memory 73 is a concept including a semiconductor memory such as a RAM and a ROM, and an external storage device such as a hard disk and a DVD-ROM. Functionally, a storage area for storing program software 81 in which the operation control procedure of the head mounted display 1 is described, and display position related data 82 which is data used when calculating the amount of movement of the female screw portion 9c. A storage area for storing is set. In addition, a storage area for storing captured image data 83 that is data related to an image captured by the imaging device 12 is set. In addition, a storage area for storing drawing image data 84 that is image data drawn by the drawing apparatus 10 is set. In addition, a work area for the CPU 72, a storage area that functions as a temporary file, and other various storage areas are set.

  The CPU 72 performs control to project a virtual image on the half mirror 3 according to the program software 81 stored in the memory 73. The CPU 72 includes a display position control unit 85 as a specific function implementing unit. The display position control unit 85 outputs an instruction signal to the mirror moving unit driving device 74 and drives the mirror moving unit 9 to control to move the half mirror 3 and the drawing device 10.

  In addition, the CPU 72 includes an imaging control unit 86. The imaging control unit 86 outputs an instruction signal for imaging to the imaging device 12 and controls the imaging device 12 to image the eyeball 2c. The imaging device 12 stores the captured image in the memory 73. In addition, the CPU 72 includes an image calculation unit 87. The image calculation unit 87 inputs photographed image data 83 obtained by photographing the eyeball 2 c from the memory 73. Then, the direction of the line of sight of the observer 8 is calculated using the captured image data 83. The line-of-sight detection unit is configured by the imaging control unit 86, the image calculation unit 87, the imaging device 12, and the like.

  In addition, the CPU 72 includes a drawing device control unit 88. The drawing device control unit 88 inputs drawing image data 84 from the memory 73. Then, the drawing image data 84 and drawing start / stop instruction signals are transferred to the drawing apparatus 10.

  In addition, the CPU 72 includes a drawing information communication unit 89. The drawing information communication unit 89 communicates with the video signal output device 21 via the input device 77 and the output device 78 and receives the drawing image data 84. The drawing information communication unit 89 stores the drawing image data 84 in the memory 73. In the present embodiment, each function described above is realized by program software using the CPU 72. However, when each function described above can be realized by a single electronic circuit (hardware) that does not use the CPU 72, It is also possible to use such an electronic circuit.

  Next, a drawing method for drawing a virtual image on the half mirror 3 using the head mounted display 1 described above will be described with reference to FIGS. FIG. 10 is a flowchart showing a drawing method. 11 to 12 are schematic diagrams for explaining a drawing method. In the flowchart of FIG. 10, step S <b> 1 is a photographing process, and the imaging device 12 is a process of photographing the eyeball 2 c. Next, the process proceeds to step S2. Step S2 is a line-of-sight calculation step. This step is a step of calculating a place where the line of sight of the observer 8 intersects the half mirror 3. Next, the process proceeds to step S3. Step S3 is a display position moving step. This step is a step in which the mirror moving unit 9 moves the drawing device 10 and the half mirror 3. Next, the process proceeds to step S5. Step S4 is a drawing process. This step is a step in which the drawing apparatus 10 forms a virtual image on the half mirror 3. Next, the process proceeds to step S5. Steps S1 to S3 and step S4 are performed in parallel. Step S5 is an end determination step. When drawing is not finished, the process proceeds to step S1 and step S4. When drawing is finished, the driving of the head mounted display 1 is finished. Drawing is completed by the above steps.

  Next, the drawing method will be described in detail with reference to FIGS. 11 to 12 in association with the steps shown in FIG. FIG. 11A is a diagram corresponding to the photographing process in step S1. As shown in FIG. 11A, the imaging device 12 images the eyeball 2c. The right imaging device 12a captures the right eye, and the left imaging device 12b captures the left eye. The shape of the white eye, black eye, and pupil 2d of the eyeball 2c is photographed. The imaging control unit 86 outputs an instruction signal for imaging to the imaging device 12. The imaging device 12 inputs an instruction signal to photograph the eyeball 2 c and stores it in the memory 73 as photographed image data 83.

  FIG. 11B and FIG. 11C are diagrams corresponding to the line-of-sight calculation step in step S2. FIG. 11B shows the case where the observer 8 turns his gaze to the right side in the figure. The image calculation unit 87 calculates a distance 92 from the image center 90 a that is the center of the image 90 to the pupil center 91 a that is the center of the pupil image 91. In the calculation of the pupil center 91a, the center of gravity of the pupil image 91 may be obtained and used as the pupil center 91a. The pupil center 91a may be calculated using a boundary line between white eyes and black eyes.

  The display position related data 82 includes a data table indicating the relationship between the position where the line of sight of the pupil 2d intersects the half mirror 3 and the distance 92. Then, the image calculation unit 87 calculates the position where the line of sight intersects the half mirror 3 using the data table, the data of the distance 92, and the information that the pupil image 91 is to the right.

  FIG.11 (c) has shown the case where the observer 8 turned his eyes to the left side in the figure. At this time, the image calculation unit 87 similarly calculates the distance 92. Then, the image calculation unit 87 calculates the position where the line of sight intersects the half mirror 3 using the data table, the data of the distance 92, and the information that the pupil image 91 is to the left.

  FIGS. 12A to 12C are diagrams corresponding to the display position moving process in step S3 and the drawing process in step S4. As shown in FIG. 12A, the line of sight 93 faces the front of the human head 2 when the pupil 2 d faces the front. An optimum point 3e is set on the half mirror 3, and the concave surface 3d and the hologram sheet 27 are formed so that an optimum image can be observed when the optimum point 3e is on the line of sight 93. In step S <b> 3, the display position control unit 85 controls the mirror moving unit 9 so that the optimum point 3 e overlaps the position where the line of sight 93 intersects the half mirror 3. In step S4, the drawing apparatus 10 emits the laser beam 22. At this time, the observer 8 can observe a clear virtual image.

  As shown in FIG. 12B, the line of sight 93 faces the left side of the human head 2 when the pupil 2d faces the left side in the figure. In step S1, the imaging device 12 captures the pupil 2d, and in step S2, the image calculation unit 87 calculates the position where the line of sight 93 intersects the half mirror 3. In step S <b> 3, the display position control unit 85 detects the position of the female screw portion 9 c of the mirror moving unit 9 via the mirror moving unit driving device 74. The female screw portion 9 c is connected to the half mirror 3. The display position related data 82 includes data on the position of the optimum point 3e with respect to the female screw portion 9c. The display position control unit 85 calculates the position of the optimum point 3e from the display position related data 82 and the position information of the female screw portion 9c.

  Next, the display position control unit 85 controls the mirror moving unit 9 so that the optimum point 3 e overlaps the position where the line of sight 93 intersects the half mirror 3. As a result, since the optimum point 3e is located on the line of sight 93, the observer 8 can observe a clear virtual image when the drawing apparatus 10 emits the laser light 22 in step S4.

  As shown in FIG. 12C, the line of sight 93 is directed to the right side of the human head 2 when the pupil 2d is directed to the right side in the drawing. Also at this time, the display position control unit 85 drives the mirror moving unit 9 so that the optimum point 3e overlaps the position where the line of sight 93 intersects the half mirror 3. As a result, since the optimum point 3e is located on the line of sight 93, the observer 8 can observe a clear virtual image when the drawing apparatus 10 emits the laser light 22 in step S4.

  When the observer 8 moves the line of sight 93 left and right, the imaging control unit 86 and the image calculation unit 87 detect the direction of the line of sight 93. Then, the display position control unit 85 controls the position of the half mirror 3 so that the optimum point 3e is positioned on the line of sight 93. At this time, the position of the drawing apparatus 10 is also controlled together with the half mirror 3. As a result, the drawing apparatus 10 emits the laser light 22 from the place where the laser light 22 reflected by the half mirror 3 passes through the pupil 2d. Therefore, the observer 8 can observe a clear virtual image.

As described above, this embodiment has the following effects.
(1) According to the present embodiment, the half mirror 3 includes the right mirror 3a that displays a virtual image for the right eye of the observer 8 and the left mirror 3b that displays a virtual image for the left eye. The right mirror 3a is located at a location facing the right eye of the viewer 8, and the left mirror 3b is located at a location facing the left eye of the viewer. The center of gravity of the mirror moving unit 9 that moves the right mirror 3a and the left mirror 3b is located between the right mirror 3a and the left mirror 3b.

  Since the screw rod rotating part 9a of the mirror moving part 9 generates a force to move the half mirror 3 and the drawing apparatus 10, it is a heavy part. When the heavy screw rod rotating portion 9a is on the right or left side of the eye, the weight cannot be balanced, so that the head mounted display 1 is easily tilted. Compared to this structure, in the structure of the present embodiment, the screw rod rotating portion 9a is located between the right mirror 3a and the left mirror 3b. Since the center of gravity of the mirror moving unit 9 is located between the right mirror 3a and the left mirror 3b, the head mounted display 1 can be made difficult to tilt with respect to the human head 2.

  (2) According to the present embodiment, the connecting portion 24 connects the drawing device 10 and the half mirror 3. When the mirror moving unit 9 moves the half mirror 3, the drawing device 10 moves in conjunction with the half mirror 3. Therefore, the mirror moving unit 9 can move the half mirror 3 and the drawing apparatus 10 in conjunction with each other. The head mounted display 1 can reduce the number of moving devices as compared with a moving device that moves the half mirror 3 and a moving device that moves the drawing device 10. As a result, the number of moving devices can be reduced, so that the structure can be easily manufactured.

  (3) According to the present embodiment, the mirror moving unit 9 moves the right mirror 3 a and the left mirror 3 b with one motor 28. When a motor for driving the right mirror 3a and a motor for driving the left mirror 3b are provided, there are two motors. Compared to this time, in the present embodiment, the number of motors can be reduced. As a result, since the number of motors can be reduced, the head mounted display 1 can be easily manufactured.

  (4) According to this embodiment, when the observer 8 who observes the virtual image moves the line of sight 93, the imaging device 12, the imaging control unit 86, and the image calculation unit 87 detect the line of sight 93 of the observer 8. Then, the control unit 17 controls the mirror moving unit 9, and the mirror moving unit 9 moves the drawing apparatus 10 and the half mirror 3 in conjunction with each other. Thereby, the virtual image can be moved in accordance with the movement of the line of sight 93 of the observer 8. The head mounted display 1 can project a virtual image so that the laser light 22 passes through the pupil 2d of the observer 8. Therefore, the head mounted display 1 can display a clear image in accordance with the line of sight 93 of the observer 8.

  (5) According to this embodiment, the half mirror 3 is installed in the mirror protection part 5. The mirror protection part 5 is provided with a light-transmitting first window part 5a and a second window part 5b facing each other. The laser beam 22 is irradiated to the half mirror 3 through the first window portion 5a, and the half mirror 3 can form a virtual image. When the half mirror 3 is moved by the guide 11, the half mirror 3 is installed in the mirror protection unit 5 and protected by the mirror protection unit 5. Therefore, it is possible to prevent the half mirror 3 from being rubbed in contact with the observer 8.

  (6) According to this embodiment, the half mirror 3 has the plate-like member 3c on which the hologram sheet 27 is installed. The hologram sheet 27 diffracts the laser beam 22 and changes the traveling direction of the laser beam 22. Therefore, the unevenness of the plate-like member 3c can be made shallow. Even when the laser beam 22 strikes the hologram sheet 27, the heat of the hologram sheet 27 can be conducted to the plate-like member 3c to suppress the temperature rise.

  (7) According to this embodiment, the 1st window part 5a and the 2nd window part 5b are installed on both sides of the half mirror 3. As shown in FIG. Accordingly, a part of the light 26 passing through the second window portion 5b can pass through the half mirror 3 and further pass through the first window portion 5a. Therefore, the observer 8 can receive the light 26 that passes through the first window portion 5a, the second window portion 5b, and the half mirror 3. As a result, the observer 8 can see the scenery through the head mounted display 1. Furthermore, since a virtual image is drawn on the half mirror 3, the observer 8 can see the virtual image and the scenery superimposed.

(Second Embodiment)
Next, an embodiment of a head mounted display will be described with reference to FIG. FIG. 13 is a schematic perspective view showing the structure of the head mounted display. This embodiment is different from the first embodiment in that a stage for moving the drawing apparatus 10 is provided without the connecting portion 24. Note that description of the same points as in the first embodiment is omitted.

  That is, in the present embodiment, as shown in FIG. 13, the head mounted display 96 as an image display device is not provided with the connecting portion 24 that connects the half mirror 3 and the drawing device 10. The drawing apparatus 10 is provided with a moving unit that moves the drawing apparatus 10 in the front-rear direction 7a and a stage 97 as a second moving unit. The stage 97 includes a fixed table, a moving table, and a linear motion mechanism that moves the moving table relative to the fixed table. Various mechanisms such as a linear motor, a device combining a cam and a rotary motor, and a device combining a screw rod and nut and a rotary motor can be used as the linear motion mechanism.

  The fixed table is installed on the half mirror frame 4, and the moving table is connected to the drawing apparatus 10. Then, when the linear motion mechanism moves the moving table with respect to the fixed table, the drawing device 10 moves in the front-rear direction 7 a with respect to the half mirror frame 4.

  When the observer 8 who observes the virtual image moves the line of sight 93, the imaging device 12, the imaging control unit 86, and the image calculation unit 87 detect the line of sight 93 of the observer 8. Then, the control unit 17 controls the mirror moving unit 9 and the stage 97. The stage 97 moves the drawing apparatus 10 in the front-rear direction 7a. The mirror moving unit 9 moves the half mirror 3 in the left-right direction 7b. The control unit 17 moves the half mirror 3 and the drawing apparatus 10 in conjunction with each other. Thereby, the virtual image can be moved in accordance with the movement of the line of sight 93 of the observer 8. The head mounted display 96 can project a virtual image so that the laser light 22 passes through the observer's pupil. Therefore, the head mounted display 96 can display a clear image in accordance with the line of sight 93 of the observer 8.

As described above, this embodiment has the following effects.
(1) According to this embodiment, the mirror moving unit 9 moves the half mirror 3 and the stage 97 moves the drawing apparatus 10. The mirror moving unit 9 and the stage 97 are parts that generate force and are heavy parts. At this time, since heavy portions are dispersed in a plurality of locations, the head mounted display 96 can be easily supported.

(Third embodiment)
Next, an embodiment of a head mounted display will be described with reference to FIG. FIG. 14 is a schematic cross-sectional view of the main part showing the structure of the head mounted display. This embodiment is different from the first embodiment in that the half mirror has a structure in which a hologram sheet is installed in the frame portion. Note that description of the same points as in the first embodiment is omitted. The right-eye half mirror will be described. The left-eye half mirror also has the same structure and action, and a description thereof will be omitted.

  That is, in the present embodiment, as shown in FIG. 14, a head mounted display 100 as an image display device includes a half mirror 101 as a display unit. The half mirror 101 is installed inside the mirror protection unit 5. The half mirror 101 includes a frame portion 101a having a rectangular frame shape. The frame portion 101 a is movable in the left-right direction 7 b along the inner periphery of the mirror protection portion 5.

  A thin film 101b is installed inside the frame 101a, and a surface of the thin film 101b facing the human head 2 is a concave surface 101c. The hologram sheet 27 is installed on the concave surface 101c. The half mirror 101 has a frame portion 101a on which the hologram sheet 27 is installed. Since the frame portion 101a has rigidity, it has strength as a structure. Therefore, the half mirror 101 can be lightened by thinning the portion irradiated with the laser beam 22. As a result, the half mirror 101 can be moved with a small force and good response.

(Fourth embodiment)
Next, an embodiment of a head mounted display will be described with reference to FIG. FIG. 15 is a schematic cross-sectional view of the main part showing the structure of the head mounted display. This embodiment is different from the first embodiment in that the half mirror does not have the plate-like member 3c and the hologram sheet constitutes the half mirror. Note that description of the same points as in the first embodiment is omitted. The right-eye half mirror will be described. The left-eye half mirror also has the same structure and action, and a description thereof will be omitted.

  That is, in this embodiment, as shown in FIG. 15, the head mounted display 104 as an image display device includes a half mirror 105 as a display unit. The half mirror 105 is installed inside the mirror protection unit 106. The half mirror 105 is made of a hologram sheet. The mirror protection part 106 has a structure in which the cavity 25 is sandwiched between a plate-like first window part 106a and a second window part 106b that are light transmissive.

  The half mirror 105 moves in the cavity 25 along the first window portion 106a and the second window portion 106b. The first window portion 106a and the second window portion 106b are flat, and the half mirror 105 has a flat thin plate shape. The half mirror 105 may be formed in an arc shape by providing irregularities on the first window portion 106a and the second window portion 106b. The laser beam 22 can be easily condensed on the pupil 2d.

  Since the half mirror 105 is made of a hologram sheet, the half mirror 105 can be lightened. As a result, the half mirror 105 can be moved with a small force and good response.

Note that the present embodiment is not limited to the above-described embodiment, and various changes and improvements can be added by those having ordinary knowledge in the art within the technical idea of the present invention. A modification will be described below.
(Modification 1)
In the first embodiment, two imaging devices 12 are installed, the right imaging device 12a and the left imaging device 12b. The line of sight 93 may be detected using one of the right imaging device 12a and the left imaging device 12b. Then, the display position control unit 85 may control the positions of both the left and right half mirrors 3 and the drawing apparatus 10 using the detected data of the line of sight 93. Since the number of components is reduced, the head mounted display 1 can be easily manufactured.

(Modification 2)
In the first embodiment, the half mirror 3 is moved by sliding with the inner surface of the mirror protection unit 5. A low friction sliding surface may be provided between the half mirror 3 and the mirror protection part 5. Further, a guide rail may be installed between the half mirror 3 and the mirror protector 5. The half mirror 3 can be moved with a small force.

(Modification 3)
In the first embodiment, the first window part 5 a and the second window part 5 b are installed in the mirror protection part 5. Depending on the application in which the head mounted display 1 is used, only the first window 5a may be installed and the second window 5b may be opened. Only the second window 5b may be installed and the first window 5a may be opened. Furthermore, you may expose the half mirror 3 except the 1st window part 5a and the 2nd window part 5b.

(Modification 4)
In the first embodiment, the concave surface 3 d is provided on the half mirror 3. When the reflection angle of the laser beam 22 can be controlled only by the hologram sheet 27, the concave surface 3d may be flat. Since the shape of the plate-like member 3c is simplified, the plate-like member 3c can be easily manufactured.

(Modification 5)
In the first embodiment, the mirror protector 5 is installed on the half mirror frame 4. The half mirror frame 4 and the mirror protection unit 5 may be integrated. Since the number of parts is reduced, the head mounted display 1 can be easily manufactured.

(Modification 6)
In the first embodiment, the half mirror 3 is moved in the left-right direction 7b. Further, a stage for moving the half mirror 3 in the vertical direction 7c may be installed. Even when the line of sight 93 moves in the vertical direction 7c in addition to the horizontal direction 7b, the half mirror 3 can be moved to display a clear virtual image.

(Modification 7)
In the first embodiment, the second window portion 5b is made light-transmitting so that the scenery and the virtual image that can be seen through the second window portion 5b can be seen overlapping each other. The second window 5b may be made of a material that does not transmit light. The head mounted display 1 can be a device for viewing only a virtual image.

(Modification 8)
In the first embodiment, the light source unit 43 is installed in the drawing apparatus 10. The light source unit 43 may be installed in the control unit 17 and the laser beam 22 may be guided to the drawing unit 35 using an optical fiber. Since the drawing apparatus 10 can be lightened, fatigue when the head mounted display 1 is mounted can be reduced.

(Modification 9)
In the first embodiment, the drawing unit 35 realizes scanning in two directions with one electromagnet. The drawing unit 35 may be configured to scan in two directions with two electromagnets. The operation can be easily controlled. The drawing unit 35 performs main scanning and sub-scanning with one light reflecting surface 44. A reflection surface for main scanning and a reflection surface for sub-scanning may be provided. Scan control can be facilitated. Further, the drawing unit 35 may drive the light reflecting surface 44 by a driving element using a piezoelectric element or static electricity other than the electromagnet.

(Modification 10)
In the first embodiment, the two drawing devices 10, that is, the right drawing device 10 a and the left drawing device 10 b are provided to provide a stereo display. A monocular display device including one drawing device 10 may be used. Since the number of components is reduced, the head mounted display 1 can be easily manufactured.

(Modification 11)
In the first embodiment, the torque of the motor 28 is transmitted to the screw rod 9b via the first gear 29 and the second gear 30. The screw rod 9b may be used as the rotating shaft of the motor 28. Since the first gear 29 and the second gear 30 are not required, the head mounted display 1 can be easily manufactured.

(Modification 12)
In the third embodiment, the concave surface 101c is formed on the thin film 101b of the half mirror 101, and the hologram sheet 27 is installed on the concave surface 101c. In addition, the hologram sheet 27 may be formed in a curved shape, and the hologram sheet 27 may be installed directly on the frame portion 101a. Since the shape of the half mirror 101 becomes simple, it can be easily manufactured. Further, since there is no thin film 101b, the half mirror 101 can be lightened. When the hologram sheet 27 may be a flat surface, the flat hologram sheet 27 may be installed on the frame portion 101a. Since the process of forming the hologram sheet 27 can be reduced, the half mirror 101 can be easily manufactured.

  DESCRIPTION OF SYMBOLS 1,96 ... Head mounted display as an image display apparatus, 3 ... Half mirror as a display part, 3a ... Right mirror as a 1st display part, 3b ... Left mirror as a 2nd display part, 8 ... Observer, 9 Mirror moving unit as moving unit and first moving unit, 12 Imaging device as sight line detecting unit, 17 Control unit, 22 Laser beam, 24 Connecting unit as moving unit, 28 Motor as drive source 35 ... Drawing unit, 43 ... Light source unit, 44 ... Light reflecting surface as a mirror, 86 ... Imaging control unit as a line-of-sight detection unit, 87 ... Image calculation unit as a line-of-sight detection unit, 97 ... Moving unit and second movement Stage as a department.

Claims (4)

A light source unit for emitting laser light;
A drawing unit for drawing the laser beam by reflecting the laser beam on a mirror and rotating the mirror;
A display unit that reflects the laser beam to form a virtual image;
A moving unit that moves in conjunction with the drawing unit and the display unit;
A line-of-sight detector that detects the line of sight of an observer observing the virtual image;
A control unit that controls the moving unit according to the movement of the line of sight,
The display unit includes a first display unit that displays the virtual image for the right eye of the observer;
A second display unit that displays the virtual image for the left eye of the observer,
The moving unit includes a first moving unit that moves the first display unit and the second display unit,
An image display device, wherein the center of gravity of the first moving unit is located between the first display unit and the second display unit. The image display device according to claim 1,
The image display apparatus according to claim 1, wherein the moving unit includes a connecting unit that connects the drawing unit and the display unit. The image display device according to claim 1,
The image display apparatus, wherein the moving unit includes a second moving unit that moves the drawing unit. The image display device according to any one of claims 1 to 3,
The image display apparatus according to claim 1, wherein the first moving unit moves the first display unit and the second display unit with one driving source.

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