Head-mounted display with half mirror area

A head-mounted display includes: a scanning unit that scans signal light modulated according to an image signal; a display unit on which the signal light from the scanning unit is incident and that is transmissive to visible light, the display unit including a half mirror area reflecting the signal light from the scanning unit and a transmission area having a transmittance higher than that of the half mirror area for visible light; and a control unit that scans, based on a use condition, the signal light over an area including the transmission area.

BACKGROUND

1. Technical Field

The present invention relates to a head-mounted display.

2. Related Art

Heretofore, a head-mounted display (hereinafter referred to as “HMD”) including an image display device that displays an image by, for example, scanning light with a scanning unit has been known (for example, refer to JP-A-2011-76503).

However, the HMD has a problem in that the HMD does not have a function of allowing an observer to indicate his/her intention to an observed person. Examples of the indication of the intention include indicating a physical disorder. Specifically, when the observer is a disabled person, the observer sometimes cannot indicate properly a physical disorder or the like to the observed person. Another example of the indication of the intention is the case in which when an HMD includes an imaging unit as in the HMD described above, an image of the observed person is sometimes captured irrespective of the observed person's intention. That is, even when an image of the observed person is being captured, nothing is shown clearly on the HMD, and the observer does not indicate that the image is being captured to the observed person. Therefore, it is difficult for the observed person to know whether or not the image is being captured.

SUMMARY

APPLICATION EXAMPLE 1

A head-mounted display according to this application example includes: a scanning unit that scans signal light modulated according to an image signal; a display unit on which the signal light from the scanning unit is incident and that is transmissive to visible light, the display unit including a half mirror area reflecting the signal light from the scanning unit and a transmission area having a transmittance higher than that of the half mirror area for visible light; and a control unit that scans, based on a use condition, the signal light over an area including the transmission area.

According to the application example, the signal light is incident on the transmission area based on the use condition. With this configuration, since the signal light is emitted from the transmission area, the observer can indicate his/her intention to the observed person. Hence, it is possible to provide the head-mounted display having a function of allowing the observer to indicate his/her intention to the observed person.

APPLICATION EXAMPLE 2

In the head-mounted display according to the application example described above, it is preferable that the use condition includes a first condition and a second condition, and that the control unit scans the signal light over the half mirror area in the first condition and scans the signal light over the area including the transmission area in the second condition.

According to this application example, an image is displayed on the display unit in the first condition, and the control unit scans the signal light over the area including the transmission area in the second condition. With this configuration, since the signal light is emitted from the transmission area in the second condition, the observer can indicate his/her intention to the observed person.

APPLICATION EXAMPLE 3

In the head-mounted display according to the application example described above, it is preferable that the head-mounted display further includes an imaging unit that captures an image, and that the control unit applies the second condition when driving the imaging unit.

According to this application example, since the signal light is incident on the transmission area when the imaging unit is driven, the signal light is emitted from the transmission area. With this configuration, the observer indicates that an image is being captured by the imaging unit mounted on the head-mounted display to the observed person, so that secret filming, cheating, information leakage, and the like can be prevented.

APPLICATION EXAMPLE 4

In the head-mounted display according to the application example described above, it is preferable that the transmission area is positioned outside a scanning area where the signal light is scanned over the half mirror area, and that the control unit scans the signal light over the area including the transmission area by expanding a scanning angle range more in the second condition than in the first condition.

According to this application example, the control unit can scan the signal light over the transmission area.

APPLICATION EXAMPLE 5

In the head-mounted display according to the application example described above, it is preferable that the scanning unit scans the signal light by resonance in a first direction and scans the signal light by non-resonance in a second direction intersecting the first direction, and that the control unit expands the scanning angle range in the second direction more in the second condition than in the first condition.

According to this application example, since the scanning angle range of non-resonant scanning is expanded, adjustment of a resonant frequency required when expanding the scanning angle range of resonant scanning is unnecessary. With this configuration, the scanning angle range can be expanded easier than in the case of expanding the scanning angle range of resonant scanning.

APPLICATION EXAMPLE 6

In the head-mounted display according to the application example described above, it is preferable that the transmission area includes a diffusion area having a diffuse transmittance higher than that of the half mirror area for visible light.

According to this application example, the signal light incident on the diffusion area is diffused. With this configuration, it is possible to expand a range that can be used for allowing the observer to indicate his/her intention to the observed person. The “diffuse transmittance” as used herein means the intensity ratio of a diffused light component to incident light in a visible light area.

APPLICATION EXAMPLE 7

In the head-mounted display according to the application example described above, it is preferable that a diffusion film is formed in the diffusion area.

According to this application example, the diffusion area can be easily formed.

APPLICATION EXAMPLE 8

In the head-mounted display according to the application example described above, it is preferable that the area including the transmission area is the half mirror area and the transmission area.

According to this application example, when the control unit scans the signal light over the transmission area, the signal light can be scanned over the half mirror area. With this configuration, even when the control unit scans the signal light over the transmission area, an image can be displayed on the display unit.

APPLICATION EXAMPLE 9

In the head-mounted display according to the application example described above, it is preferable that the transmission area is adjacent to the half mirror area.

According to this application example, the scanning angle range that is expanded when the control unit scans the signal light from the half mirror area to the area including the transmission area can be made small. The “adjacent” as used herein includes vicinity arrangement in a non-contact state.

APPLICATION EXAMPLE 10

In the head-mounted display according to the application example described above, it is preferable that the head-mounted display further includes an eyeglass-type frame including a front portion including a nose pad portion, and that the scanning unit is positioned on the nose pad portion side of the front portion and on the side closer to the center of the front portion than an optical axis of the signal light reflected by the display unit.

According to this application example, since the scanning unit is positioned on the nose pad portion side of the front portion, a portion bulging forward relative to the observer's face can be prevented from being formed in the head-mounted display. Moreover, since the scanning unit is positioned on the side closer to the center of the front portion than the optical axis of the signal light reflected by the display unit, a portion bulging laterally relative to the observer's face can be prevented from being formed in the head-mounted display.

APPLICATION EXAMPLE 11

In the head-mounted display according to the application example described above, it is preferable that the head-mounted display further includes a signal light generating unit that generates the signal light, that the frame includes a temple portion connected to the front portion and a modern portion as an end of the temple portion, and that the signal light generating unit is disposed at the modern portion.

According to this application example, the weight balance of the head-mounted display can be made excellent.

APPLICATION EXAMPLE 12

In the head-mounted display according to the application example described above, it is preferable that the scanning unit further includes a base portion on which a reflector having a reflecting surface reflecting the signal light is disposed, an axial portion that supports the base portion oscillatable about a first axis, a frame body portion that is oscillatable about a second axis intersecting the first axis, a permanent magnet that is disposed at the frame body portion, a coil, and a voltage applying unit that applies a voltage to the coil, that the base portion and the frame body portion are connected with the axial portion, that the permanent magnet is arranged in plan view in a direction inclined to the first axis and the second axis, and that the voltage applying unit applies to the coil a voltage obtained by superimposing on each other a first voltage at a first frequency causing the base portion to oscillate about the first axis and a second voltage at a second frequency causing the frame body portion to oscillate about the second axis.

According to this application example, the base portion on which the reflector is disposed can be oscillated about the first axis and the second axis, so that scanning can be easily performed on the display unit.

APPLICATION EXAMPLE 13

In the head-mounted display according to the application example described above, it is preferable that the scanning unit scans the signal light over the area including the transmission area by making the second voltage higher in the second condition than in the first condition.

According to this application example, the scanning angle range can be easily expanded.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, preferred Embodiments 1 to 5 of an HMD according to the invention will be described with reference to the accompanying drawings. In the drawings described below, the scale of each member or the like is different from the actual scale so that the member or the like has a recognizable size.

FIG. 1Ais an elevation view showing a schematic configuration of an HMD according to Embodiment 1.FIG. 1Bis a plan view showing a schematic configuration of the HMD according to Embodiment 1.FIG. 2is a partially enlarged view of the HMD according to Embodiment 1.FIG. 3is a block diagram showing a configuration of a driving unit.FIGS. 4A and 4Bare explanatory graphs each showing an example of a generated voltage.FIG. 5is a schematic configuration view of a scanning light emitting unit according to Embodiment 1.FIG. 6is a plan view of an optical scanner according to Embodiment 1.FIG. 7Ais a cross-sectional view (cross-sectional view taken along line A-A) of the optical scanner according to Embodiment 1.FIG. 7Bis a cross-sectional view (cross-sectional view taken along line B-B) of the optical scanner according to Embodiment 1.FIG. 8is a schematic view showing a schematic configuration of a display unit according to Embodiment 1.FIG. 9Ais a schematic view showing a schematic configuration of the display unit and a scanning area in a first condition according to Embodiment 1.FIG. 9Bis a schematic view showing a schematic configuration of the display unit and the scanning area in a second condition according to Embodiment 1.

InFIGS. 1A,1B, and2, for convenience of description, an X-axis, a Y-axis, and a Z-axis are shown as three axes orthogonal to each other. The tip side of the illustrated arrow of each axis is defined as “positive side” while the base side thereof is defined as “negative side”. Moreover, a direction parallel to the X-axis is referred to as “X-axis direction; a direction parallel to the Y-axis is referred to as “Y-axis direction”; and a direction parallel to the Z-axis is referred to as “Z-axis direction”. The X-axis, the Y-axis, and the Z-axis are set such that when an HMD1described later is mounted on a head H of an observer, the X-axis direction is a front-back direction of the head H, the Y-axis direction is an up-and-down direction of the head H, and the Z-axis direction is a left-and-right direction of the head H.

As shown inFIGS. 1A and 1B, the HMD1of Embodiment 1 is an HMD having an eyeglass-like appearance. The HMD1is used by being mounted on the observer's head H and allows the observer to visually recognize an image based on a virtual image with an outside world image in a superimposed state. The HMD1includes a frame2, a signal generating unit3, scanning light emitting units4, and display units6. In Embodiment 1, the HMD1further includes a CCD (charge coupled device) camera700as an imaging unit.

In the HMD1, the signal generating unit3generates signal light modulated according to image information, the scanning light emitting units4two-dimensionally scan the signal light to emit scanning light, and the display units6reflect the scanning light toward eyes EY of the observer. With this configuration, it is possible to allow the observer to visually recognize the virtual image according to the image information.

The HMD1forms separately a right-eye virtual image and a left-eye virtual image. For convenience of description, however, a configuration for forming the right-eye virtual image will be representatively shown in the drawings. A configuration for forming the left-eye virtual image is similar to that of the right-eye virtual image, and therefore, the illustration thereof is omitted.

Hereinafter, each portion of the HMD1will be sequentially described in detail.

Frame

As shown inFIGS. 1A,1B, and2, the frame2has an eyeglass frame-like shape and has a function of supporting the signal generating unit3, the scanning light emitting units4, the display units6, and the CCD camera700.

Moreover, the frame2includes a front portion610, temple portions620, and modern portions630. The front portion610supports the scanning light emitting units4, the display units6, the CCD camera700, and nose pad portions21. The temple portions620are connected to the front portion610and abut on ears EA of the observer. The modern portions630are each an end of the temple portion620opposite from the front portion610. The nose pad portions21abut on the observer's nose NS at the time of use, and support the HMD1relative to the observer's head H. The front portion610includes rim portions611and a bridge portion612.

The nose pad portions21are configured to be capable of adjusting the position of the frame2relative to the observer at the time of use. The shape of the frame2is not limited to that shown in the drawings as long as the frame can be mounted on the observer's head H.

Signal Generating Unit

As shown inFIGS. 1B and 2, the signal generating unit3is attached to the modern portion630of the frame2. That is, the signal generating unit3is arranged on the opposite side of the observer's ear EA to the eye EY at the time of use. With this configuration, the weight balance of the head-mounted display can be made excellent.

The signal generating unit3has two functions: one is to generate signal light that is scanned by an optical scanner42as a scanning unit of the scanning light emitting unit4described later; and the other is to generate a drive signal for driving the optical scanner42. As shown inFIG. 3, the signal generating unit3includes a signal light generating unit31, a drive signal generating unit32, a control unit33, and a lens34. The signal light generating unit31generates the signal light that is scanned by the optical scanner42of the scanning light emitting unit4described later.

The signal light generating unit31includes a plurality of light sources311R,311G, and311B, a plurality of driver circuits312R,312G, and312B, and a light combining unit313. The light source311R emits red light; the light source311G emits green light; and the light source311B emits blue light. With the use of these three color lights, a full-color image can be displayed.

Although not particularly limited, a laser diode or an LED, for example, can be used for each of the light sources311R,311G, and311B. The light sources311R,311G, and311B are electrically connected to the driver circuits312R,312G, and312B, respectively.

The driver circuit312R has a function of driving the light source311R; the driver circuit312G has a function of driving the light source311G; and the driver circuit312B has a function of driving the light source311B. Three (three color) lights emitted from the light sources311R,311G, and311B driven by the driver circuits312R,312G, and312B are incident on the light combining unit313.

The light combining unit313combines the lights from the plurality of light sources311R,311G, and311B. With this configuration, it is possible to reduce the number of optical fibers for transmitting the signal light generated by the signal light generating unit31to the scanning light emitting unit4. Therefore, in Embodiment 1, the signal light can be transmitted from the signal generating unit3to the scanning light emitting unit4via one optical fiber7disposed along the temple portion620of the frame2.

In Embodiment 1, the light combining unit313includes two dichroic mirrors313aand313b. The dichroic mirror313ahas a function of transmitting red light therethrough and reflecting green light. The dichroic mirror313bhas a function of transmitting red light and green light therethrough and reflecting blue light.

With the use of the dichroic mirrors313aand313b, the three color lights, red light, green light, and blue light, from the light sources311R,311G, and311B are combined to form signal light. In Embodiment 1, the light sources311R,311G, and311B are arranged such that optical path lengths of the red light, green light, and blue light from the light sources311R,311G, and311B are equal to each other.

The light combining unit313is not limited to the above-described configuration using the dichroic mirrors313aand313b, but may be composed of, for example, an optical waveguide, an optical fiber, or the like. The signal light generated by the signal light generating unit31is input through the lens34to the optical fiber7. Then, the signal light is transmitted via the optical fiber7to the optical scanner42of the scanning light emitting unit4described later.

With the use of the optical fiber7that introduces the signal light generated by the signal light generating unit to the optical scanner42, the flexibility of the installation position of the signal light generating unit31is increased. The lens34condenses the signal light generated by the signal light generating unit31to input the signal light to the optical fiber7. The lens34is disposed as necessary, and can be omitted. For example, by disposing a lens between each of the light sources311R,311G, and311B and the light combining unit313instead of the lens34, the signal light can be input to the optical fiber7.

The drive signal generating unit32generates a drive signal for driving the optical scanner42of the scanning light emitting unit4described later. The drive signal generating unit32includes a driver circuit321(first driver circuit) and a driver circuit322(second driver circuit). The driver circuit321generates a first drive signal V1 used for scanning in a first direction (horizontal scanning) of the optical scanner42. The driver circuit322generates a second drive signal V2 and a third drive signal V3 used for scanning in a second direction (vertical scanning) orthogonal to the first direction of the optical scanner42.

For example, as shown inFIG. 4A, the driver circuit321generates the first drive signal V1 (voltage for horizontal scanning) that changes periodically with a period T1. As shown inFIG. 4B, the driver circuit322generates the second drive signal V2 (voltage for vertical scanning) that changes periodically with a period T2 different from the period T1, and the third drive signal V3 (voltage for vertical scanning) whose voltage is higher than that of the second drive signal V2. The first drive signal V1, the second drive signal V2, and the third drive signal V3 will be described in detail later.

The drive signal generating unit32is electrically connected to the optical scanner42of the scanning light emitting unit4described later via a signal line (not shown). With this configuration, the drive signals (the first drive signal V1, the second drive signal V2, and the third drive signal V3) generated by the drive signal generating unit32are input to the optical scanner42of the scanning light emitting unit4described later. The driver circuits312R,312G, and312B of the signal light generating unit31and the driver circuits321and322of the drive signal generating unit32are electrically connected to the control unit33.

The control unit33has a function of controlling, based on a video signal (image signal), the driving of the driver circuits312R,312G, and312E of the signal light generating unit31and the driver circuits321and322of the drive signal generating unit32. With this configuration, the signal light generating unit31generates signal light modulated according to image information, and the drive signal generating unit32generates a drive signal according to the image information. Further, the control unit33has a function of driving the CCD camera700and controlling its imaging operation and the like.

Scanning Light Emitting Unit

As shown inFIGS. 1A,1B, and2, the scanning light emitting unit4is attached in the vicinity of the bridge portion612(in other words, in the vicinity of the center of the front portion610) of the frame2. That is, the scanning light emitting unit4is arranged so as to be positioned on the observer's nose NS side of the eye EY at the time of use. In other words, the scanning light emitting unit4is positioned between the observer's both eyes EY as viewed from the front of the observer at the time of use. Further in other words, the scanning light emitting unit4is positioned on the bridge portion612side (that is, the center side of the front portion610) of the position of the optical axis of the signal light reflected by the display unit6. With this configuration, a portion bulging laterally relative to the observer's face can be prevented from being formed in the HMD1.

The scanning light emitting unit4is attached inside the frame2. That is, the scanning light emitting unit4is arranged on the observer side of the display unit6described later (that is, the nose pad portion21side of the front portion610) at the time of use. With this configuration, a portion bulging forward relative to the observer's face can be prevented from being formed in the HMD1.

The scanning light emitting unit4is attached via a moving mechanism5to the frame2at a position different from the nose pad portion21. The moving mechanism5is configured so as to be capable of moving the scanning light emitting unit4in a direction along the Z-axis relative to the frame2. Therefore, the scanning light emitting unit4can move in the direction along the Z-axis relative to the display unit6described later. With this configuration, the image forming position (position at which the entire scanning light that extends in the horizontal direction and the vertical direction forms an image) of scanning light formed by scanning the signal light can be adjusted in an eye-width direction independently of adjusting the position of the nose pad portion21.

As shown inFIG. 5, the scanning light emitting unit4includes a housing41, the optical scanner42, a lens (coupling lens)43, a condensing position adjusting mechanism44, and a lens (condensing lens)45. The housing41accommodates the optical scanner42and the lens43. The housing41has a dust- and drip-proof structure. To the housing41, the optical fiber7is attached via the condensing position adjusting mechanism44. The condensing position adjusting mechanism44will be described in detail later.

Further, the lens45is attached to the housing41. The lens45constitutes a portion of the housing41(a portion of a wall). With this configuration, the number of components can be suppressed, and a reduction in size of the device can be achieved. The lens45will be described in detail later.

The optical scanner42is an optical scanner that two-dimensionally scans signal light from the signal light generating unit31. Scanning light is formed by scanning the signal light with the optical scanner42. As shown inFIG. 6, the optical scanner42includes a base portion11, a pair of axial portions12aand12b(first axial portion), a frame body portion13, a pair of axial portions14aand14b(second axial portion), a support portion15, a permanent magnet16, and a coil17. In other words, the optical scanner42has a so-called gimbal structure.

The base portion11and the pair of axial portions12aand12bconstitute a first vibrating system that oscillates (reciprocally pivots) about a Y1 axis (first axis). Moreover, the base portion11, the pair of axial portions12aand12b, the frame body portion13, the pair of axial portions14aand14b, and the permanent magnet16constitute a second vibrating system that oscillates (reciprocally pivots) about an X1 axis (second axis).

The optical scanner42includes a signal superimposing unit18(a voltage applying unit; refer toFIG. 5). The permanent magnet16, the coil17, the signal superimposing unit18, and the drive signal generating unit32constitute a driving unit that drives the first vibrating system and the second vibrating system (that is, oscillates the base portion11about the X1 axis and the Y1 axis).

Hereinafter, each portion of the optical scanner42will be sequentially described in detail. The base portion11has a plate shape. A reflector111having light reflectivity is disposed on an upper surface (one of surfaces) of the base portion11. In Embodiment 1, the base portion11has a circular shape in plan view. The plan-view shape of the base portion11is not limited to that, and may be, for example, an ellipse, or a polygon such as a quadrilateral. Moreover, the base portion11may have a shape having a dynamic deflection reducing structure that reduces the dynamic deflection of a portion at which the reflector111is disposed.

The frame body portion13has a frame shape, and is disposed to surround the base portion11. In other words, the base portion11is disposed inside the frame body portion13having a frame shape. The frame body portion13is supported by the support portion15via the axial portions14aand14b. Moreover, the base portion11is supported by the frame body portion13via the axial portions12aand12b. Inner and outer edges of the frame body portion13each have a circular shape in plan view. The shape of the frame body portion13is not limited to that shown in the drawing as long as the shape is a frame shape surrounding the base portion11.

Each of the axial portions12aand12band the axial portions14aand14bis elastically deformable. The axial portions12aand12bcouple the base portion11with the frame body portion13so that the base portion11can pivot (oscillate) about the Y1 axis (first axis). The axial portions14aand14bcouple the frame body portion13with the support portion15so that the frame body portion13can pivot (oscillate) about the X1 axis (second axis) orthogonal to the Y1 axis.

The axial portions12aand12bare arranged so as to face each other with the base portion11therebetween. Each of the axial portions12aand12bhas a longitudinal shape extending in a direction along the Y1 axis. Each of the axial portions12aand12bis connected at one end to the base portion11, and connected at the other end to the frame body portion13. Each of the axial portions12aand12bis arranged such that the central axis thereof coincides with the Y1 axis. Each of the axial portions12aand12bis torsionally deformed in association with the oscillation of the base portion11about the Y1 axis.

The axial portion14aand the axial portion14bare arranged so as to face each other with the frame body portion13(interposed) therebetween. Each of the axial portions14aand14bhas a longitudinal shape extending in a direction along the X1 axis. Each of the axial portions14aand14bis connected at one end to the frame body portion13, and connected at the other end to the support portion15. Each of the axial portions14aand14bis arranged such that the central axis thereof coincides with the X1 axis. Each of the axial portions14aand14bis torsionally deformed in association with the oscillation of the frame body portion13about the X1 axis.

As described above, the base portion11is oscillatable about the Y1 axis, while the frame body portion13is oscillatable about the X1 axis. Therefore, the base portion11can oscillate (reciprocally pivot) about two axes, the X1 axis and the Y1 axis orthogonal to each other. The shape of each of the axial portions12aand12band the axial portions14aand14bis not limited to that described above, and may have, for example, a bent or curved portion or a branched portion at at least one place in the middle of the axial portion.

The base portion11, the axial portions12aand12b, the frame body portion13, the axial portions14aand14b, and the support portion15are integrally formed. For example, the structure including the base portion11, the axial portions12aand12b, the frame body portion13, the axial portions14aand14b, and the support portion15can be formed by etching a silicon substrate. With this configuration, vibration characteristics of the first vibrating system and the second vibrating system can be made excellent. The structure can also be formed by etching an SOI substrate having a first Si layer (device layer), an SiO2layer (BOX layer), and a second Si layer (handle layer) stacked in this order.

In this case, for example, the base portion11, the axial portions12aand12b, the frame body portion13, the axial portions14aand14b, and the support portion15are integrally formed of the first Si layer. The structure including the base portion11, the axial portions12aand12b, the frame body portion13, the axial portions14aand14b, and the support portion15may include as necessary the SiO2layer and the second Si layer.

On a lower surface (surface on the side opposite to the reflector111) of the frame body portion13, the permanent magnet16is bonded. The method for bonding the permanent magnet16with the frame body portion13is not particularly limited, and for example, a bonding method using adhesive can be used. The permanent magnet16is arranged in plan view so as to be inclined to the X1 axis and the Y1 axis.

In Embodiment 1, the permanent magnet16has a longitudinal shape (rod-like shape) extending in a direction inclined to the X1 axis and the Y1 axis. The permanent magnet16is magnetized in its longitudinal direction. That is, the permanent magnet16is magnetized such that one end thereof is the south pole and the other end is the north pole. The permanent magnet16is disposed in plan view so as to be symmetrical about an intersection point of the X1 axis and the Y1 axis.

In Embodiment 1, as shown inFIGS. 7A and 7B, a recess161is disposed in an upper surface (one of surfaces) of the permanent magnet16. With this configuration, the base portion11that pivots can be prevented from contacting the permanent magnet16. In Embodiment 1, an example is described in which one permanent magnet16is placed at the frame body portion13. However, the invention is not limited to that, and for example, two permanent magnets may be placed at the frame body portion13. In this case, for example, two permanent magnets having a longitudinal shape may be placed at the frame body portion13so as to face each other with the intersection point of the X1 axis and the Y1 axis therebetween and be parallel to each other.

An inclined angle θ of the magnetized direction (extending direction) of the permanent magnet16relative to the X1 axis is not particularly limited. However, the inclined angle is preferably from 30° to 60°, more preferably from 45° to 60°, and further preferably 45°. By disposing the permanent magnet16in this manner, the base portion11can pivot smoothly and reliably about the X1 axis.

As the permanent magnet16, for example, a neodymium magnet, a ferrite magnet, a samarium-cobalt magnet, an alnico magnet, a bonded magnet, or the like can be preferably used. The permanent magnet16is obtained by magnetizing a hard magnetic substance, and formed by, for example, placing a hard magnetic substance before magnetization at the frame body portion13and then magnetizing the hard magnetic substance. This is because when the permanent magnet16that has been already magnetized is intended to be placed at the frame body portion13, the permanent magnet16cannot be placed at a desired position in some cases due to an influence of an external magnetic field or magnetic fields of other components.

Just below the permanent magnet16, the coil17is disposed. That is, the coil17is disposed so as to face a lower surface of the frame body portion13. With this configuration, a magnetic field generated from the coil17can efficiently act on the permanent magnet16. With this configuration, energy saving and a reduction in size of the optical scanner42can be achieved. The coil17is electrically connected to the signal superimposing unit18(refer toFIG. 5).

By applying a voltage from the signal superimposing unit18to the coil17, a magnetic field having a magnetic flux orthogonal to the X1 axis and the Y1 axis is generated from the coil17. The signal superimposing unit18includes an adder (not shown) that superimposes the first drive signal V1 and the second drive signal V2 (or the third drive signal V3) on each other, and applies the superimposed voltage to the coil17. The first drive signal V1, the second drive signal V2, and the third drive signal V3 will be described in detail.

As described above, the driver circuit321generates the first drive signal V1 (voltage for horizontal scanning) that changes periodically with the period T1 as shown inFIG. 4A. That is, the driver circuit321generates the first drive signal V1 at a first frequency (1/T1). The first drive signal V1 has a sine-wave-like waveform. Therefore, the optical scanner42can effectively perform main scanning with light. The waveform of the first drive signal V1 is not limited to that.

The first frequency (1/T1) is not particularly limited as long as the frequency is suitable for horizontal scanning, and is preferably from 10 to 40 kHz. In Embodiment 1, the first frequency is set so as to be equal to a torsional resonant frequency (f1) of the first vibrating system (torsional vibrating system) composed of the base portion11and the pair of axial portions12aand12b. That is, the first vibrating system is designed (manufactured) such that the torsional resonant frequency f1 thereof is a frequency suitable for horizontal scanning. With this configuration, the pivot angle of the base portion11about the Y1 axis can be increased.

On the other hand, the driver circuit322generates, in the case of the first condition described later, the second drive signal V2 (voltage for vertical scanning in the first condition) that changes periodically with the period T2 different from the period T1 as shown inFIG. 4B. Moreover, the driver circuit322generates, in the case of the second condition described later, the third drive signal V3 (voltage for vertical scanning in the second condition) whose voltage is higher than that of the second drive signal V2 as shown inFIG. 4B.

The second drive signal V2 (and the third drive signal V3) has a sawtooth-wave-like waveform. Therefore, the optical scanner42can effectively perform vertical scanning (sub-scanning) with light. The waveform of the second drive signal V2 (and the third drive signal V3) is not limited to that.

A second frequency (1/T2) is not particularly limited as long as the frequency is different from the first frequency (1/T1) and suitable for vertical scanning, and is preferably from 30 to 80 Hz (about 60 Hz). As described above, the frequency of the second drive signal V2 (and the third drive signal V3) is set to about 60 Hz, while the frequency of the first drive signal V1 is set to 10 to 40 kHz as described above. Therefore, at a frequency suitable for drawing on the display, the base portion11can pivot about each of the two axes (the X1 axis and the Y1 axis) orthogonal to each other. However, as long as the base portion11can pivot about each of the X1 axis and the Y1 axis, the combination of the frequencies of the first drive signal V1 and the second drive signal V2 (and the third drive signal V3) is not particularly limited.

In Embodiment 1, the frequency of the second drive signal V2 (and the third drive signal V3) is adjusted so as to be different from the torsional resonant frequency (resonant frequency) of the second vibrating system (torsional vibrating system) composed of the base portion11, the pair of axial portions12aand12b, the frame body portion13, the pair of axial portions14aand14b, and the permanent magnet16.

The frequency (second frequency) of the second drive signal V2 (and the third drive signal V3) is preferably lower than that (first frequency) of the first drive signal V1. That is, the period T2 is preferably longer than the period T1. With this configuration, the base portion11can pivot more reliably and more smoothly about the X1 axis at the second frequency while pivoting about the Y1 axis at the first frequency.

When the torsional resonant frequency of the first vibrating system is f1 [Hz] and the torsional resonant frequency of the second vibrating system is f2 [Hz], f1 and f2 preferably satisfy the relation of f1>f2, and more preferably satisfy the relation of f1≧10f2. With this configuration, the base portion11can pivot more smoothly about the X1 axis at the frequency of the second drive signal V2 (or the third drive signal V3) while pivoting about the Y1 axis at the frequency of the first drive signal V1. In contrast to this, when the relation of f1≦f2 is satisfied, the first vibrating system may vibrate at the second frequency.

Next, a method for driving the optical scanner42will be described. In Embodiment 1, as described above, the frequency of the first drive signal V1 is set equal to the torsional resonant frequency of the first vibrating system. The frequency of the second drive signal V2 (and the third drive signal V3) is set to a value different from the torsional resonant frequency of the second vibrating system and so as to be lower than that of the first drive signal V1 (for example, the frequency of the first drive signal V1 is set to 15 kHz, and the frequency of the second drive signal V2 (and the third drive signal V3) is set to 60 Hz).

For example, the first drive signal V1 shown inFIG. 4Aand the second drive signal V2 (or the third drive signal V3) shown inFIG. 4Bare superimposed on each other in the signal superimposing unit18, and the superimposed voltage is applied to the coil17.

Then, with the first drive signal V1, two magnetic fields are alternately switched: one of the magnetic fields attracts one end (the north pole) of the permanent magnet16to the coil17and causes the other end (the south pole) of the permanent magnet16to move away from the coil17(this magnetic field is referred to as “magnetic field A1”); and the other magnetic field causes the one end (the north pole) of the permanent magnet16to move away from the coil17and attracts the other end (the south pole) of the permanent magnet16to the coil17(this magnetic field is referred to as “magnetic field A2”).

As described above, the permanent magnet16is arranged such that the respective ends (magnetic poles) thereof are positioned at two areas divided by the Y1 axis. That is, in plan view ofFIG. 6, the north pole of the permanent magnet16is positioned on one side of the Y1 axis, while the south pole of the permanent magnet16is positioned on the other side. Therefore, with the alternate switching of the magnetic field A1 and the magnetic field A2, a vibration having a torsional vibration component about the Y1 axis is excited in the frame body portion13. In association with the vibration, the base portion11pivots about the Y1 axis at the frequency of the first drive signal V1 while torsionally deforming the axial portions12aand12b.

The frequency of the first drive signal V1 is equal to the torsional resonant frequency of the first vibrating system. Therefore, with the first drive signal V1, the base portion11can efficiently pivot about the Y1 axis. That is, even when the vibration of the frame body portion13having the torsional vibration component about the Y1 axis is small, the pivot angle of the base portion11about the Y1 axis in association with the vibration can be increased.

On the other hand, with the second drive signal V2 (or the third drive signal V3), two magnetic fields are alternately switched: one of the magnetic fields attracts one end (the north pole) of the permanent magnet16to the coil17and causes the other end (the south pole) of the permanent magnet16to move away from the coil17(“magnetic field B1”); and the other magnetic field causes the one end (the north pole) of the permanent magnet16to move away from the coil17and attracts the other end (the south pole) of the permanent magnet16to the coil17(“magnetic field B2”).

As described above, the permanent magnet16is arranged such that the respective ends (magnetic poles) thereof are positioned at two areas divided by the X1 axis. That is, in plan view ofFIG. 6, the north pole of the permanent magnet16is positioned on one side of the X1 axis, while the south pole of the permanent magnet16is positioned on the other side. Therefore, with the alternate switching of the magnetic field B1 and the magnetic field32, the frame body portion13pivots, together with the base portion11, about the X1 axis at the frequency of the second drive signal V2 (or the third drive signal V3) while torsionally deforming each of the axial portions14aand14b.

The frequency of the second drive signal V2 (and the third drive signal V3) is set extremely low compared to the frequency of the first drive signal V1. The torsional resonant frequency of the second vibrating system is set lower than that of the first vibrating system. Therefore, the base portion11can be prevented from pivoting about the Y1 axis at the frequency of the second drive signal V2 (and the third drive signal V3).

According to the optical scanner42described above, since the base portion11including the reflector111having light reflectivity is oscillated about each of two axes orthogonal to each other, reductions in size and weight of the optical scanner42can be achieved. The signal light (scanning light) scanned by the optical scanner42is emitted to the outside of the housing41through the lens45. The lens45is disposed between the optical scanner42and the display unit6.

The lens45is a single lens that condenses, between the optical scanner42and the display unit6, the signal light from the optical scanner42so that the signal light reflected by the display unit6becomes parallel light. That is, it can be said that the lens45constitutes a focus adjusting unit that adjusts the focal position of the signal light according to a position to be scanned so that the signal light reflected by the display unit6becomes parallel light. By disposing the lens45, the design flexibility of the posture, shape, or the like of the display unit6is increased.

The condensing position adjusting mechanism (condensing position adjusting unit)44shown inFIG. 5has a function of moving an edge surface of the optical fiber7on the optical scanner42side in an axial direction of the optical fiber7to thereby adjust the condensing position of signal light. With this configuration, the condensing position of scanning light formed by scanning the signal light with the optical scanner42is adjusted with a comparatively simple and small configuration, so that an image visually recognized by the observer can be optimized.

As shown inFIG. 5, the condensing position adjusting mechanism44includes a male screw member441fixed to the optical fiber7and a female screw member442rotatably supported relative to the housing41and engaged with the male screw member441. By rotating the female screw member442relative to the housing41, the condensing position adjusting mechanism44can move the optical fiber7together with the male screw member441in the axial direction of the optical fiber7.

The signal light emitted from the optical fiber7attached to the housing41via the condensing position adjusting mechanism44is incident through the lens43on the reflector111of the optical scanner42. The lens43has a function of adjusting the spot diameter of the signal light emitted from the optical fiber7. Moreover, the lens43also has a function of adjusting the radiation angle of the signal light emitted from the optical fiber7to substantially collimate the signal light.

Display Unit

As shown inFIGS. 1A,1B, and2, the display unit6is attached to the rim portion611included in the front portion610of the frame2. That is, the display unit6is arranged, at the time of use, so as to be positioned in front of the observer's eye EY and on the far side of the optical scanner42relative to the observer. With this configuration, a portion bulging forward relative to the observer's face can be prevented from being formed in the HMD1. The signal light from the optical scanner42is incident on the display unit6, and the display unit6is transmissive to visible light.

As shown inFIG. 8, the display unit6includes a half mirror area510in which an image due to scanning of the signal light is displayed, and a transmission area520having a transmittance higher than that of the half mirror area510for visible light. In Embodiment 1, the transmission area520is adjacent to the half mirror area510. The half mirror area510has a function of partially reflecting the signal light from the optical scanner42and transmitting therethrough external light directed from the outside of the display unit6to the observer's eye at the time of use.

Specifically, as shown inFIG. 2, the half mirror area510includes a transparent substrate (light-transmissive portion)61that transmits the external light therethrough and a diffraction grating62that is supported by the transparent substrate61and reflects the signal light from the optical scanner42. It can be said that the half mirror area510itself is a half mirror, and it can also be said that a half mirror such as the diffraction grating62is disposed on the transparent substrate61. With this configuration, the diffraction grating62can have various optical characteristics, the number of components of an optical system can be reduced, and the design flexibility can be enhanced.

For example, with the use of a hologram element as the diffraction grating62, the emitting direction of the signal light reflected by the half mirror area510can be adjusted. The half mirror area510is not limited to the configuration described above, and may have a configuration obtained by, for example, forming a semi-transmissive reflection film composed of a metal thin film, a dielectric multilayer film, or the like on a transparent substrate.

The signal light incident on the transmission area520is emitted to the outside of the display unit6. In Embodiment 1, the transmission area520includes a diffusion area521having a diffuse transmittance higher than that of the half mirror area510for visible light. With this configuration, the signal light incident on the diffusion area521is diffused. The diffusion area521is disposed by forming a diffusion film on the transparent substrate61. Examples of the diffusion film include, for example, a resin film containing a diffusion material therein.

Next, a scanning area530will be described. The scanning area530is an area over which signal light from the optical scanner42is scanned. The range of the scanning area530changes depending on the use condition of the HMD1. The use condition of the HMD1includes the first condition and the second condition. In the first condition, the control unit33scans the signal light over the half mirror area510. That is, as shown inFIG. 9A, the scanning area530exists in the half mirror area510.

In the second condition, the control unit33scans the signal light over an area including the transmission area520(the diffusion area521). That is, as shown inFIG. 9B, the scanning area530exists across the half mirror area510and the transmission area520(the diffusion area521). With this configuration, an image is displayed on the display unit6in the first condition, and the control unit33scans, in the second condition, the signal light over the area including the transmission area520(the diffusion area521). The area including the transmission area520(the diffusion area521) is the half mirror area510and the transmission area520(the diffusion area521) in Embodiment 1.

In Embodiment 1, the control unit33applies the first condition when not driving the CCD camera700, and applies the second condition when driving the CCD camera700. With this configuration, since the signal light is incident on the transmission area520(the diffusion area521) when the CCD camera700is driven, the signal light is emitted from the transmission area520(the diffusion area521). Then, with the emitted light, the observer's intention is indicated to the observed person.

Next, a method for changing the range of the scanning area530depending on the use condition of the HMD1will be described. As described above, in the first condition, the driver circuit322generates the second drive signal V2 (voltage for vertical scanning in the first condition) that changes periodically with the period T2 different from the period T1 as shown inFIG. 4B. In the second condition, the driver circuit322generates the third drive signal V3 (voltage for vertical scanning in the second condition) whose voltage is higher than that of the second drive signal V2 as shown inFIG. 4B.

With this configuration, compared to the scanning angle range in the first condition, the scanning angle range in the second condition can be expanded. That is, the range of the scanning area530can be changed depending on the use condition of the HMD1. Since the control unit33controls the driver circuit322, it can be said that the control unit33expands the scanning angle range in the second condition compared to the scanning angle range in the first condition.

According to the HMD1according to Embodiment 1, the following advantageous effects can be obtained.

The display unit6includes the half mirror area510that partially reflects signal light from the optical scanner42and the transmission area520having a transmittance higher than that of the half mirror area for visible light. The control unit33that scans the signal light over the half mirror area510in the first condition and scans the signal light over the area including the transmission area520in the second condition is included. With this configuration, an image is displayed on the display unit6in the first condition, and the control unit33scans the signal light over the area including the transmission area520in the second condition. Hence, it is possible to provide the HMD1having a function of allowing the observer to indicate his/her intention to the observed person in the second condition.

The control unit33applies the second condition when driving the CCD camera700. Therefore, when the CCD camera700is driven, the signal light is incident on the transmission area520, and the signal light is emitted from the transmission area520. Hence, it is possible to provide the FIND1having a function of allowing the observer to indicate that the CCD camera700mounted on the HMD is capturing an image to the observed person.

Since the transmission area520includes the diffusion area521having a diffuse transmittance higher than that of the half mirror area510for visible light. Therefore, the signal light incident on the diffusion area521is diffused. With this configuration, it is possible to expand a range that can be used for allowing the observer to indicate his/her intention to the observed person.

Since the area including the transmission area520is the half mirror area510and the transmission area520, the control unit33can scan signal light over the half mirror area510when scanning the signal light over the transmission area520. With this configuration, even when the control unit33scans the signal light over the transmission area520, an image can be displayed on the display unit6.

Since the transmission area520is adjacent to the half mirror area510, the scanning angle range that is expanded when the control unit33scans from the half mirror area510to the area including the transmission area520can be made small.

The transmission area520is positioned outside the scanning area530where the signal light is scanned over the half mirror area510. By expanding the scanning angle range more in the second condition than in the first condition, the control unit33scans the signal light over the area including the transmission area520. With this configuration, the control unit33can scan the signal light over the transmission area520.

The optical scanner42scans the signal light by resonance in the first direction, and scans the signal light by non-resonance in the second direction intersecting the first direction. The control unit33expands the scanning angle range in the second direction more in the second condition than in the first condition. With this configuration, since the scanning angle range of non-resonant scanning is expanded, adjustment of a resonant frequency required when expanding the scanning angle range of resonant scanning is unnecessary. Therefore, the scanning angle range can be expanded easier than in the case of expanding the scanning angle range of resonant scanning.

Since the diffusion area521is disposed by forming a diffusion film, the diffusion area521can be easily formed.

The optical scanner42is positioned on the nose pad portion21side of the front portion610and on the side closer to the center of the front portion610than the optical axis of the signal light reflected by the display unit6. With this configuration, since the optical scanner42is positioned on the nose pad portion21side of the front portion610, a portion bulging forward relative to the observer's face can be prevented from being formed in the HMD1. Further, since the optical scanner42is positioned on the side closer to the center of the front portion610than the optical axis of the signal light reflected by the display unit6, a portion bulging laterally relative to the observer's face can be prevented from being formed in the HMD1.

Since the signal light generating unit31is disposed at the modern portion630, the weight balance of the HMD1can be made excellent.

The base portion11and the frame body portion13are connected with the axial portions12aand12b. The permanent magnet16is arranged in plan view in a direction inclined to the X-axis and the Y-axis. The signal superimposing unit18applies to the coil17a voltage obtained by superimposing on each other a first voltage at the first frequency and a second voltage at the second frequency. The first voltage causes the base portion11to oscillate about the Y-axis. The second voltage causes the frame body portion13to oscillate about the X-axis. With this configuration, the base portion11on which the reflector111is disposed can be oscillated about the X-axis and the Y-axis while reducing the number of components.

The optical scanner42makes the second voltage (voltage of the second drive signal V2) higher in the second condition than in the first condition to thereby scan the signal light over the area including the transmission area520. Therefore, the scanning angle range can be easily expanded.

Next, Embodiment 2 of the invention will be described.

FIGS. 10A and 10Bare schematic views each showing a schematic configuration of the display unit6and the scanning area530according to Embodiment 2.

Hereinafter, Embodiment 2 will be described mainly on differences from Embodiment 1, and descriptions of similar matters are omitted. InFIGS. 10A and 10B, configurations similar to those of Embodiment 1 are denoted by the same references and numerals. An HMD1A of Embodiment 2 is similar to the HMD1of Embodiment 1, excepting that the transmission area520does not include the diffusion area521, that the CCD camera700is not included, and that the use condition is different.

FIG. 10Ashows a schematic configuration of the display unit6and the scanning area530in the first condition.FIG. 10Bshows a schematic configuration of the display unit6and the scanning area530in the second condition. As shown inFIGS. 10A and 10B, the transmission area520does not include the diffusion area521.

In Embodiment 1, the control unit33applies the second condition when driving the CCD camera700. In Embodiment 2, however, the second condition can be applied when the observer wants to indicate some kind of intention to the observed person irrespective of the CCD camera700. Examples of the indication of the intention include indicating a physical disorder. Specifically, when the observer is a disabled person, the observer sometimes cannot indicate properly a physical disorder or the like to the observed person.

When the observer does not have a physical disorder or the like, the observer can observe an image using the scanning area530of the HMD1A as the half mirror area510as shown inFIG. 10A. However, when the observer has a physical disorder or the like, the observer applies the second condition via the control unit33, and can use the scanning area530of the HMD1A as the transmission area520as shown inFIG. 10B. At this time, signal light incident on the transmission area520is emitted from the transmission area520.

Hence, according to the HMD1A according to Embodiment 2, the following advantageous effect can be obtained in addition to the advantageous effects of Embodiment 1. That is, since the observer can apply the second condition when wanting to indicate some kind of intention to the observed person, it is possible to provide the HMD1A having a function of allowing the observer to indicate his/her intention to the observed person.

Next, Embodiment 3 of the invention will be described.

FIGS. 11A and 11Bare schematic views each showing a schematic configuration of the display unit6and the scanning area530according to Embodiment 3.

Hereinafter, Embodiment 3 will be described mainly on differences from Embodiment 1, and descriptions of similar matters are omitted. InFIGS. 11A and 11B, configurations similar to those of Embodiment 1 are denoted by the same references and numerals. An HMD1B of Embodiment 3 is similar to the HMD1of Embodiment 1, excepting that the position of the transmission area520(the diffusion area521) is different, that a fourth drive signal V4 (voltage for horizontal scanning in the second condition) is used instead of the third drive signal V3, and that the scanning area530in the second condition is different. In the following, the upper side, lower side, left side, and right side inFIGS. 11A and 11Bare referred to as “up”, “down”, “left”, and “right”, respectively, for convenience of description.

FIG. 11Ashows a schematic configuration of the display unit6and the scanning area530in the first condition.FIG. 11Bshows a schematic configuration of the display unit6and the scanning area530in the second condition. As shown inFIG. 11A, the transmission area520(the diffusion area521) is positioned to the left of the scanning area530in the first condition.

In Embodiment 1, the control unit33expands the scanning angle range in the up-and-down direction (second direction) in the second condition compared to the scanning angle range in the up-and-down direction (second direction) in the first condition. In Embodiment 3, on the other hand, the control unit33expands a scanning angle range in the left-and-right direction (first direction) in the second condition compared to a scanning angle range in the left-and-right direction (first direction) in the first condition.

Specifically, in the second condition, the driver circuit321generates the fourth drive signal V4 (not shown) that changes periodically with the period T1 and whose voltage is higher than that of the first drive signal V1. With this configuration, in the second condition, the scanning angle range in the left-and-right direction (first direction) can be expanded.

Hence, according to the HMD1B according to Embodiment 3, it is possible to provide the HMD1B having a function of allowing the observer to indicate his/her intention to the observed person in the second condition.

Next, Embodiment 4 of the invention will be described.

FIGS. 12A and 12Bare schematic views each showing a schematic configuration of the display unit6and the scanning area530according to Embodiment 4.

Hereinafter, Embodiment 4 will be described mainly on differences from Embodiment 1, and descriptions of similar matters are omitted. InFIGS. 12A and 12B, configurations similar to those of Embodiment 1 are denoted by the same references and numerals. An HMD1C of Embodiment 4 is similar to the HMD1of Embodiment 1, excepting that the position of the transmission area520(the diffusion area521) is different, that the third drive signal V3 and the fourth drive signal V4 are used, and that the scanning area530in the second condition is different. In the following, the upper side, lower side, left side, and right side inFIGS. 12A and 12Bare referred to as “up”, “down”, “left”, and “right”, respectively, for convenience of description.

FIG. 12Ashows a schematic configuration of the display unit6and the scanning area530in the first condition.FIG. 12Bshows a schematic configuration of the display unit6and the scanning area530in the second condition. As shown inFIG. 12A, the transmission area520(the diffusion area521) surrounds the scanning area530in the first condition.

In Embodiment 1, the control unit33expands the scanning angle range in the up-and-down direction (second direction) in the second condition compared to the scanning angle range in the up-and-down direction (second direction) in the first condition. In Embodiment 4, on the other hand, the control unit33also expands, in addition to the expansion of the scanning angle range in the up-and-down direction (second direction), the scanning angle range in the left-and-right direction (first direction) in the second condition compared to the scanning angle range in the left-and-right direction (first direction) in the first condition.

Specifically, in the second condition, the driver circuit321generates the fourth drive signal V4, and the driver circuit322generates the third drive signal V3. With this configuration, in the second condition, the scanning angle ranges in both of the left-and-right direction (first direction) and the up-and-down direction (second direction) can be expanded. InFIGS. 12A and 12B, the half mirror area510exists both inside and outside the transmission area520(the diffusion area521). However, the half mirror area located outside the transmission area520(the diffusion area521) may not be needed.

Hence, according to the HMD1C according to Embodiment 4, the following advantageous effect can be obtained in addition to the advantageous effects of Embodiment 1. That is, since the transmission area520(the diffusion area521) can be expanded compared to that of Embodiment 1, it is possible to expand a range that can be used for allowing the observer to indicate his/her intention to the observed person.

Next, Embodiment 5 of the invention will be described.

FIG. 13is a schematic view showing a schematic configuration of the display unit6according to Embodiment 5.

Hereinafter, Embodiment 5 will be described mainly on differences from Embodiment 1, and descriptions of similar matters are omitted. InFIG. 13, configurations similar to those of Embodiment 1 are denoted by the same references and numerals. An HMD1D of Embodiment 5 is similar to the HMD1of Embodiment 1, excepting that an image for the observed person is displayed in the second condition.

FIG. 13shows a schematic configuration of the display unit6and the scanning area530in the second condition. As shown inFIG. 13, “now recording” is displayed in the half mirror area510.

Hence, according to the HMD1D according to Embodiment 5, the following advantageous effect can be obtained in addition to the advantageous effects of Embodiment 1. That is, even when the observed person does not know the meaning of emission of signal light from the transmission area520(the diffusion area521), the observer can indicate his/her intention more reliably to the observed person through the confirmation of the display “now recording”. An image to be displayed is not limited to “now recording”.

Next, Embodiment 6 of the invention will be described.

FIG. 14is a schematic view showing a schematic configuration of an HMD according to Embodiment 6.

Hereinafter, Embodiment 6 will be described mainly on differences from Embodiment 1, and descriptions of similar matters are omitted. InFIG. 14, configurations similar to those of Embodiment 1 are denoted by the same references and numerals. An HMD1E of Embodiment 6 is similar to the HMD1of Embodiment 1, excepting that the invention is applied to a headset-type HMD.

The HMD1E includes a mount portion27mounted on the observer's head H and an extending portion28extending from the mount portion27. The signal generating unit3is disposed at the mount portion27. The scanning light emitting unit4and the display unit6are attached to the extending portion28.

Hence, according to the HMD1E according to Embodiment 6, it is possible to provide the HMD1E having a function of allowing the observer to indicate his/her intention to the observed person in the second condition.

Although the HMD according to the invention has been described so far based on the embodiments shown in the drawings, the invention is not limited to the embodiments. For example, in the HMD of the invention, the configuration of each portion can be replaced with any configuration having a similar function. Moreover, any other configurations can be added to each portion.

In the embodiments described above, an example has been described in which the transmission area520is the transparent substrate61. However, the transmission area520is not limited to that. It is sufficient that the transmission area520has a transmittance higher than that of the half mirror area510for visible light. When the transmission area520includes the diffusion area521, the entire of the transmission area520does not, of course, have to be the diffusion area521. The transmission area520may include partially an area that is not the diffusion area521.

In the embodiments described above, an example has been described in which signal light is scanned over the area including the transmission area520(the diffusion area521) by changing the scanning angle range. However, the invention is not limited to that. For example, a mechanism for moving the optical scanner42itself may be disposed. That is, in the second condition, signal light may be scanned over the area including the transmission area520(the diffusion area521) by moving the optical scanner42itself, instead of changing the scanning angle range, to change a scanning position. As another example, in the second condition, signal light may be scanned over the area including the transmission area520(the diffusion area521) by arranging an optical member such as a prism on an optical path and changing the optical path.

In the embodiments described above, an example has been described in which in the second condition, the control unit33scans signal light over the half mirror area510and the transmission area520(the diffusion area521). However, the invention is not limited to that. In the second condition, the control unit33may scan signal light only over the transmission area520.

In Embodiment 1, an example has been described in which the drive signal generating unit32generates the first drive signal V1, the second drive signal V2, and the third drive signal V3. However, the invention is not limited to that. A plurality of drive signals different in voltage or the like may be generated according to the use condition.

In the embodiments described above, an example has been described in which a diffusion film is used for forming the diffusion area521. However, the invention is not limited to that. A diffusing function may be provided by subjecting the transmission area520to surface roughening.

In the embodiments described above, an example has been described in which the diffuse transmittance of the diffusion area521does not change depending on the use condition. However, the invention is not limited to that. For example, the diffuse transmittance of the diffusion area521in the second condition may be higher compared to the diffuse transmittance of the diffusion area521in the first condition. With this configuration, since the amount of external light that is diffused by the diffusion area521and then incident on the observer's eye can be reduced in the first condition, poor visibility due to the external light can be attenuated. A method for changing the diffuse transmittance of the diffusion area521can be realized by using, for example, polymer dispersed liquid crystal (PDLC).

In the embodiments described above, an example has been described in which the signal light generating unit31is positioned at the modern portion630. However, the invention is not limited to that. The signal light generating unit31may be positioned anywhere as long as the signal light generating unit31can introduce signal light to the optical scanner42. For example, signal light may be introduced from a portable terminal or the like different from the HMD through the optical fiber7.

In the embodiments described above, an example has been described in which a moving magnet-type electromagnetic driving system is adopted as a driving unit that causes the base portion11to oscillate (reciprocally pivot). However, the driving unit is not limited to that, and may be a moving coil-type electromagnetic driving system. Moreover, a driving system other than the electromagnetic driving system, such as an electrostatic driving system or a piezoelectric driving system may be adopted.

In the embodiments described above, an example has been described in which the optical scanner42has a so-called gimbal structure. However, the invention is not limited to that. For example, a uniaxial optical scanner may be used.

In the embodiments described above, an example has been described in which the CCD camera700is supported by the frame2. However, the invention is not limited to that. The CCD camera700may be disposed anywhere as long as the CCD camera700is electrically connected to the control unit33or wirelessly communicable therewith.

In the embodiments described above, an example has been described in which the imaging unit is the CCD camera700. However, the invention is not limited to that. A CMOS (complementary metal oxide semiconductor) camera or the like may be used.

In the embodiments described above, an example has been described in which right- and left-eye virtual images are formed. However, the invention is not limited to that, and may be configured to form any one of right- and left-eye virtual images.

In the embodiments described above, examples have been described in which the invention is applied to eyeglass- and headset-type HMDs. However, the invention is not limited to them as long as an HMD is mountable on the head H. For example, the invention can also be applied to a helmet-type HMD.

The entire disclosure of Japanese Patent Application No, 2012-284461, filed Dec. 27, 2012 is expressly incorporated by reference herein.