JP3537261B2 - Relative angle detection device and virtual reality providing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relative angle detecting device for detecting a rotation angle of a mounted object within a predetermined plane, and to provide a relative angle detecting device using the device according to the direction in which the user faces. The present invention relates to a virtual reality providing apparatus for changing an image, and more particularly to a relative angle detecting apparatus using polarized light and a virtual reality providing apparatus using the same.

[0002]

2. Description of the Related Art In recent years, virtual reality (virtual reality) providing devices that give a sense of being as if in a three-dimensional space by giving an image shifted to both eyes by an amount corresponding to parallax have been put to practical use. It is expected to be applied to wider fields. Various methods for providing images with parallax shift to both eyes have been proposed, but at present, the most common method is called a head mounted display mounted on the head, such as a liquid crystal just before each eye. A set of a display device and a lens is arranged, and an image is independently provided to each eye. The user
By mounting a head-mounted display on the head and viewing images with different parallaxes provided to each eye, the user feels as if they are in a three-dimensional space.

In a game device, a player plays by operating buttons, keys, and the like in accordance with a provided three-dimensional space. The player plays with the head mounted display mounted on the head, but in order to provide good virtual reality, if the position or facing direction is changed, the image provided according to the change Needs to be changed. It is desirable to detect both the position and the direction and change the image in accordance with each change.

In the conventional virtual reality providing apparatus, a gyro sensor is attached to the head mounted display, and the direction of the head mounted display is detected after detecting the angular velocity of rotation. However, a gyro sensor with high detection accuracy is large and expensive, and cannot be used for a head mounted display mounted on the head. Therefore, a low-cost, lightweight gyro sensor has been used, but drift over time has been large, and it has been difficult to satisfy the demand for detection accuracy. In addition, it is necessary to be able to use the head mounted display as soon as it is mounted. However, the gyro sensor takes a long time from startup to a stable state. Therefore, there has been a demand for a lightweight, low-cost relative angle detection device capable of detecting the orientation of a head-mounted display with high accuracy.

The present invention has been made to realize a relative angle detecting device for detecting a change in the direction of a head mounted display in a virtual reality providing device. The invented relative angle detecting device provides a virtual reality providing device. The present invention is applicable to a device other than the device, and is not limited to this.
2. Description of the Related Art As a small-sized relative angle detection device in which a portion attached to a rotating object is lightweight and small, a device using polarized light is known. FIG. 6 is a diagram illustrating a relative angle detection method using polarized light.

In FIG. 6A, reference numeral 311 denotes a light source, 312 denotes a polarizing filter, 321 denotes a polarizing filter, and 331 denotes a light receiving element. The polarizing filter 321 and the light receiving element 331 are integrally mounted on the light receiving unit 320, and the light receiving unit 320 is mounted on an object whose rotation angle is to be detected. The light source 311 and the polarizing filter 312 are fixed, and emit light polarized in the direction of the arrow. Thus, the direction of polarization of the emitted light is fixed, and the direction of polarization is at any angle in a plane perpendicular to the direction of radiation. This angle becomes the reference direction.
The polarizing filter 321 and the light receiving element 331 are arranged to receive the polarized light. The light passing through the polarization filter 321 becomes the largest when the polarization directions of the polarization filters 312 and 321 coincide, and becomes the smallest when the polarization direction differs by 90 °, so that almost no light enters the light receiving element 331. Accordingly, when the polarization filter 321 is rotated, the output of the light receiving element 331 changes as shown in (2) of FIG. That is, assuming that the angle of the polarization direction of the polarization filter 321 with respect to the polarization direction of the polarization filter 312 is θ, the output of the light receiving element 331 is a function Imax (1 + cos).
θ) / 2. Therefore, if the light intensity output from the light source 311 is constant, the maximum intensity Imax of the output of the light receiving element 331 when θ is 0 ° or 180 ° is constant, and if the detected signal intensity is I, Angle θ at that time
Is represented by θ = arccos (2I / Imax−1) (1), and the angle θ is obtained from the intensity of the output signal of the light receiving element 331.
Can be calculated.

However, the conventional relative angle detection method shown in FIG. 6 has various problems such as a large error and a narrow detection range. Japanese Patent Application No. 7-321899 discloses a relative angle detection device capable of solving such a problem and a virtual reality providing device using the same. Japanese Patent Application No. 7-321899 discloses a relative angle detecting device in a plurality of modes, in which a unit mounted on a head is designed to periodically change a polarization direction of light output from a light source. There is a device that detects a change in the intensity of light passing through the polarizing plate provided in the above and detects a relative angle. FIG. 7 is a diagram showing a configuration of such a conventional example, and FIG. 8 is a diagram showing a detection signal in this conventional example.

The relative angle detecting device shown in FIG. 7 is a relative angle detecting device for detecting a rotation angle of a unit to which the light receiving unit 221 is mounted in a predetermined plane with respect to a predetermined initial direction, and is provided separately from the unit. Light source 21
0 emits polarized light whose polarization direction changes at a predetermined cycle in a direction substantially perpendicular to a predetermined plane. Light receiving unit 22
Reference numeral 1 denotes a polarizing filter 222 that receives light emitted from the light source unit 210, and the light source unit 21 that has passed through the polarizing filter.
And a light receiving element 224 for receiving the light emitted from the light emitting element. The signal from the light receiving unit 221 is transmitted to the A / D converter 2
After being converted into a digital signal at 42, the CPU 251
From the polarization direction of the light emitted from the light source unit 210 when the signal output from the light receiving element 224 is processed by a computer including the ROM 252, the RAM 253, the I / O port 254, and the like, to a predetermined value, The relative angle of the unit is calculated.

Since the polarization direction of the polarized light emitted from the light source section 210 changes at a predetermined cycle, even if the direction of the unit is constant, as shown in FIG.
Output signal changes at this predetermined cycle. For example, the polarization direction of light emitted from the light source unit 210 and the polarization filter 2
When the polarization directions of 22 coincide, that is, when the difference in direction is 0 °, the maximum value of the periodically changing value is obtained. When the difference in direction is 90 °, the minimum value is obtained, and the difference in direction is 45 °. In the case of, it is an intermediate value between the maximum value and the minimum value. Therefore, if the polarization direction of the light emitted from the light source unit 210 at the time when the output signal of the light receiving element 224 reaches a predetermined value such as a maximum value, a minimum value, or an intermediate value between the maximum value and the minimum value is detected, 22
Two polarization directions are known.

Since the intensity change of the detection signal accompanying the change of the polarization direction of the emitted light changes gradually near the maximum value and the minimum value of the output signal, it is difficult to detect the maximum value and the minimum value with high accuracy. difficult. The intensity change of the detection signal is maximum near the intermediate value between the maximum value and the minimum value, and detecting this intermediate value is advantageous from the viewpoint of detection accuracy. Therefore,
Japanese Patent Application No. 7-321899 further discloses an apparatus for detecting a time point at which an output signal reaches an intermediate value between a maximum value and a minimum value, as shown in FIG.

[0011]

SUMMARY OF THE INVENTION Japanese Patent Application No. Hei 7-32189.
In the device disclosed in No. 9, as described above, the light receiving element 2
24 is converted into a digital signal, and is processed by a computer, so that the detection signal has a maximum value Imax.
(Imax + Imin) / 2 between the minimum value and the minimum value Imin
Has been detected. The arithmetic processing for this is A
The output of the / D converter 242 is read in accordance with the sampling period, the comparison process is performed to calculate the maximum value and the minimum value, the intermediate value is calculated, and the time when the detection signal becomes the intermediate value is monitored. Requires a significant amount of computation. Therefore, in order to detect at a sufficient sampling period, it is necessary to use a high-speed and fast computer,
There is a problem that the cost increases. In addition, there is a problem that the amount of related data is large, so that the memory capacity used for the calculation is also large.

Further, the latest maximum value Imax and the minimum value Im
In order to calculate the intermediate value (Imax + Imin) / 2 based on in, the corresponding maximum value Imax and minimum value Imin
Is detected, it is detected that the signal has changed beyond the intermediate value after elapse of ３ cycle of the signal, which results in a time delay of the detection. The present invention is intended to solve such a problem, and periodically changes the polarization direction of light output from a light source, and changes the light intensity passing through a polarizing plate provided in a unit mounted on the head. It is an object of the present invention to provide a device for detecting a change in the relative angle and detecting a relative angle by using a simple and low-cost configuration so that an intermediate value between the maximum value and the minimum value can be instantaneously detected.

[0013]

In order to achieve the above object, in the relative angle detecting device according to the present invention, the output of the light receiving element is once subjected to an AC amplification, and then the analog signal processing circuit sets the intermediate value between the maximum value and the minimum value. Enable to detect a certain zero cross point. That is, the relative angle detection device of the present invention is a relative angle detection device that detects a rotation angle of a mounted unit with respect to a predetermined initial direction in a predetermined plane, and the polarization direction is substantially perpendicular to the predetermined plane. A light source unit that emits polarized light that changes at a predetermined cycle is provided separately from the unit, and a polarizing filter that receives light emitted from the light source unit,
A light receiving unit including a light receiving element that receives light emitted from the light source unit that has passed through the polarizing filter is provided integrally with the unit, and a DC component is removed from an output signal of the light receiving unit,
An AC converter that converts to a signal that changes around the zero level, a zero-cross detection circuit that detects when the output signal of the AC converter changes beyond the zero level, and a zero-cross detection circuit that outputs the AC converter Japanese Patent Application No. Hei 7 (1994) -107, further comprising arithmetic means for calculating a relative angle of a unit with respect to a predetermined initial direction from a polarization direction of light emitted from a light source unit at a time point when a time point at which a change exceeds zero level is detected. As described in US Pat. No. 3,321,899, it is advantageous in terms of detection accuracy to detect a point in time when the output signal becomes an intermediate value between the maximum value and the minimum value. In the relative angle detection device of the present invention, the detection is performed instantaneously because the time point at which the output signal becomes an intermediate value between the maximum value and the minimum value is detected by analog processing using the AC amplifier and the zero-cross detection circuit. . Moreover, the AC amplifier and the zero-cross detection circuit can be realized by a simple low-cost circuit.

If the time when the polarization direction of the light emitted from the light source unit coincides with the polarization direction of the polarization filter of the light receiving unit is defined as 0 °, the angle at which the output signal of the AC converter changes beyond zero level changes. The polarization direction of the polarization filter is ± 45 ° of the polarization direction of the emitted light. If the change in the direction of the light receiving unit is sufficiently gentle compared to the change in the polarization direction of the light emitted by the light source unit and does not change much from the angle detected immediately before, the light emitted by the light source unit By detecting a point in time at which the output signal changes beyond the zero level in synchronization with the rotation of the polarization direction, and comparing with the angle detected immediately before, a change of ± 45 ° or more can be detected.

In order to change the polarization direction of the emitted light, for example, a rotating means for rotating the polarizing filter is provided. In order to reduce the incidence of disturbance light on the light receiving unit, it is effective to provide a light shielding unit. A second aspect of the present invention provides:
By using a head mounted display having image display means attached to the user's head and providing images to both eyes of the user, and using images provided to both eyes of the user with different parallax. A virtual reality providing apparatus for providing a three-dimensional image to a user, using the relative angle detecting device to detect the direction of the head mounted display, and providing an image to be provided according to the detected direction of the head mounted display. It is characterized by changing.

When the above-mentioned initial angle setting means is provided in order to further widen the detectable angle range, a button switch is provided as the initial angle setting means, and the user operates the button switch in a predetermined direction. Indicates that the direction is the predetermined initial direction. It is desirable to provide a light blocking means to reduce light other than the polarized light from the light source unit to enter the light receiving unit,
As the light shielding means, for example, a light shielding curtain is used.

In the relative angle detecting device of the present invention, the portion of the light receiving unit attached to the object whose direction is to be detected is small and lightweight, and can be easily attached to the head mount display without impairing the operability. Further, if the initial angle setting means and the angle register are provided and the operation of determining the detected angle based on the relative angle detected immediately before is repeated, it is applicable to applications requiring a wider detection range. is there.

[0018]

FIG. 1 is a diagram showing an overall configuration of a virtual reality providing apparatus according to an embodiment of the present invention. This virtual reality providing apparatus provides a patient in need of rehabilitation with virtual reality, such as moving outdoors, and instructs the patient to operate the appliance accordingly, thereby increasing the effect of rehabilitation. .

In FIG. 1, reference numeral 100 denotes a patient undergoing rehabilitation, 101 denotes a rehabilitation device, 102 denotes a head mounted display mounted on the head of the patient 100, and 103 denotes a head mounted display. The light receiving unit of the relative angle detecting device, 111 and 112 are pillars, 11
3 is a light source unit of the relative angle detecting device, and 114 is a light source unit 11
Reference numeral 115 denotes a light source driver for driving the three light sources, reference numeral 115 denotes a light shielding curtain, reference numeral 70 denotes a control unit for controlling the entire apparatus, and reference numeral 62 denotes a button switch for setting an initial angle.

The head-mounted display 102 has display means such as a liquid crystal display for providing independent images to both eyes and a projection lens. The control unit 70 supplies an image signal to the display means so that images having different parallaxes are provided to both eyes. The patient 100 feels as if he / she is outdoors by seeing images with different parallaxes with both eyes. The patient 100 operates the rehabilitation device 101 according to an instruction provided by a sound signal or the like from the control unit 70 while viewing the provided image. Control unit 70
Detects the operation state, changes the image to be provided, and gives a feeling of moving outdoors, for example, according to the operation of the patient.

The patient 100 is a rehabilitation device 1
At the time of the operation of 01, the direction of the face is changed. In order to provide good virtual reality, it is necessary to change an image to be provided according to a change in the direction of the face. Desirably, it is desirable to detect changes in the orientation of all faces in the three axial directions and change the image accordingly, but in such an apparatus, a particular problem is a change in orientation in a horizontal plane. Here, for simplicity of description, it is assumed that only an orientation change in a horizontal plane is detected to change an image.

The light source unit 113 is disposed above the position where the patient 100 operates the rehabilitation device 101 by the columns 111 and 112. Light receiving unit 103
Are arranged above the head mounted display 102 so as to receive light from the light source unit 10. The light source driver 114 according to a control signal from the control unit 70
The lighting of the light source of the light source unit 113 is controlled. The control unit 70
The provided image is changed according to the rotation angle in the horizontal plane detected by the light receiving unit 103.

The portions of the virtual reality providing device and the rehabilitation device except for the relative angle detecting device are prior art and are not directly related to the present invention, so that further description is omitted here. FIG. 2 is a diagram illustrating a configuration of the detection unit according to the present embodiment. In the light source section 210, the light source 213 uses one light bulb having a large output light amount, and emits uniform light downward over a wide range by the reflecting mirror 214. A filter 215 is used. The polarizing filter 215 is rotated at a predetermined cycle by a motor 219 and rotating mechanisms 217 and 218. Also,
A color filter 216 is provided, and light emitted from the light source unit 210 is light in a narrow transmission wavelength range. In addition, by using an infrared LED that emits invisible light instead of a light bulb as the light source 213, light entering from a gap between the head-mounted display 102 and the face of the patient 100 is reduced, and a light-sensitive patient is It is desirable to enhance the effects of rehabilitation.

In the light receiving unit 221, the polarization filter 2
22, a light receiving element 224, and a color filter 225 are provided. The color filter 225 has a transmission wavelength range corresponding to the color filter 216 of the light source unit 210, and almost all light other than the light from the light source unit 210 is removed, so that the influence of disturbance light can be eliminated. The output signal of the light receiving element 224 is input to the AC amplifier 260 via the amplifier 241. The AC amplifier 260 includes a capacitive element C, a resistor R1,
R2 and an operational amplifier 261, and converts an output signal of the light receiving element 224 into a signal that changes substantially symmetrically around the zero level. The zero-cross detection circuit 270 detects when the output signal of the AC amplifier 260 changes after passing through the zero level. The zero-cross detection circuit 270 can be realized by, for example, combining a comparator and a monostable multivibrator.

The zero-cross detection circuit 270 is input to the computer 250 as an interrupt signal. When the computer 250 receives the interrupt signal from the zero cross detection circuit 270, the computer 250 reads the rotation angle output from the rotation angle sensor provided in the rotation mechanism 218. The computer 250 detects the rotation direction of the light receiving unit 221, that is, the head mounted display, based on the read rotation angle. Actually, a computer constituting the control unit 70 in FIG. 1 is used as the computer 250, and a part of the functions is used for the direction detection processing.

FIG. 3 is a diagram showing the relationship between the setting direction of the polarizing filter and the output signal in the embodiment. (1) of FIG.
As shown in (2), the rotation angle of the polarizing filter 215 of the light source unit changes from -180 ° to + 180 °, and returns to -180 ° at + 180 °. Default direction is 0
°, when the user wears the head mounted display 102 and faces in the initial setting direction, the polarization direction of the polarizing filter 222 of the light receiving unit 221 provided in the unit 103 arranged on the head is as shown in the figure. + 45 ° with respect to the initial setting direction. Assuming that the polarization filter 215 of the light source unit rotates as shown in the figure, the output signal changes in a sine wave form as shown by the solid line in (2) of FIG. 3 and has maximum values at -135 ° and + 45 °. , The minimum value at −45 ° and + 135 °, and −180
°, -90 °, 0 °, 90 °, 180 ° (-180 °)
Cross the zero level with. Head mounted display 1
It is sufficiently possible to suppress the error when the patient wearing No. 02 faces the initial setting direction to about ± 10 °, actually to about ± 5 °. If it is detected, the direction in which the light receiving unit 221 of the head mounted display 102 faces can be detected. When the detection signal crosses the zero level, the zero-cross detection circuit 270 outputs a zero-cross signal as shown.

When the patient changes direction by Φ as shown in FIG. 3A, the output signal changes as shown by the broken line in FIG. When the detection signal at this time passes through the zero level, the rotation angles of the polarizing filter of the light source unit are set to θ1, θ2, θ.
3, θ4, θ1, θ2-90 °, θ3 + 180
If れ ば and θ4 + 90 ° are calculated, it becomes Φ. However, what is shown is a case where Φ is a rotation in the plus direction, and when Φ is a rotation in the plus direction, θ3 becomes plus.
80 ° needs to be θ3-180 °.

FIG. 4 shows a computer 25 in the embodiment.
11 is a flowchart showing a processing operation of a zero. In this embodiment, after performing the initial initialization operation, the computer 250 performs processing such as displaying an image on the head mounted display 102, and the direction detection of the light receiving unit 221 is performed by interrupt processing of a zero cross signal. In step 901, the controller 70 moves the button switch 62 for initial angle setting to the patient 100 in the specified direction.
Instruct the user to press. In step 902, it is confirmed that the button switch 62 has been pressed. If the button switch 62 has been pressed, the process proceeds to step 903.

In step 903, it is displayed that the initial setting is being performed, and an instruction is given not to change the direction. In step 904, the light source is turned on, and in step 905, the rotation of the filter 215 is started. In step 906, the timing at which the detection signal crosses the zero level, that is, when the zero-cross signal is output, is detected within the range of the rotation angle from -45 ° to + 45 °, and the angle at that time is defined as θR.
This is the angle at which the patient 100 is initially facing. In step 907, θR is stored in the register A. In step 908, 1 is set in the register N as n.

In step 909, it is displayed that the initial setting has been completed, and the start of rehabilitation is displayed. After that, other processes are performed, and the angle detection is performed in response to an interrupt process. FIG. 5 is a flowchart illustrating a zero-crossing interrupt process performed in response to a zero-crossing signal interrupt.

When an interrupt is received, at step 951,
The rotation angle θ of the filter 215 at that time is read, θR is read from the register A in step 952, and n is read from the register N in step 953. Step 95
In step 4, θX = θ−90 × n is calculated. Step 95
In 4, it is determined whether θX−θR is within the range of ± 180 °. If it is smaller than -180 °, the routine proceeds to step 956, where 360 ° is added to θX to obtain a new θX, and +1
If it is larger than 80 °, the routine proceeds to step 957, where θX
Is subtracted from 360 ° to obtain a new θX.

In step 958, θX is output and stored in the register A. In step 958, n is incremented by 1, and in step 960, it is determined whether n is greater than 3. If it is greater than 3, n is set to -1 in step 961.
To At step 962, n is stored in the register N. This completes the zero-cross interrupt processing. As described above, according to the present invention, the point at which the detection signal passes an intermediate value between the maximum value and the minimum value, that is, the time when the detection signal passes the zero level, is automatically detected by the analog circuit, so that the detection signal is detected in the direction by the interrupt processing. It can be performed. for that reason,
There is no need for the computer to constantly detect the output signal, and the computer can perform other processing while the interrupt occurs.

[0033]

As described above, according to the present invention,
A relative angle detection device that periodically changes the polarization direction of light output from a light source, detects a change in light intensity passing through a polarizing plate provided in another unit, and detects the relative angle of the unit, is a simple low-angle detection device. With the cost configuration, it can be instantaneously detected that the value is an intermediate value between the maximum value and the minimum value. In addition, by using this relative angle detection device as a virtual reality providing device,
It is possible to easily provide a more realistic image that matches the movement of the user.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of an embodiment.

FIG. 2 is a diagram illustrating a configuration of a detection unit according to the embodiment.

FIG. 3 is a diagram illustrating a setting direction of a filter and a signal of each unit according to the embodiment.

FIG. 4 is a flowchart illustrating a processing operation in the embodiment.

FIG. 5 is a flowchart showing a processing operation at the time of interruption in the embodiment.

FIG. 6 is a diagram showing a conventional angle detection method using polarized light.

FIG. 7 is a diagram showing a configuration of a conventional relative angle detection device.

FIG. 8 is a diagram illustrating signal processing in the conventional relative angle detection device of FIG. 8;

FIG. 9 is a diagram illustrating another signal processing in the conventional relative angle detection device.

[Explanation of symbols]

62: Initial angle setting button 70 ... Control unit 100: User (patient) 102… Head mounted display 210: Light source unit 215 ... Polarizing filter 221 ... Light receiving unit 222: Polarizing filter 224 ... light receiving element 250 ... Computer 260 ... AC amplifier 270 ... Zero cross detection circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-170004 (JP, A) JP-A-8-261738 (JP, A) JP-A-61-2504 (JP, A) JP-A-8- 159734 (JP, A) JP-A-7-298165 (JP, A) JP-A-7-318332 (JP, A) JP-A 57-102808 (JP, U) JP-A 63-122212 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01B 11/26

Claims (10)

(57) [Claims] 1. A relative angle detection device for detecting a rotation angle of a mounted unit with respect to a predetermined initial direction within a predetermined plane, wherein a polarization direction is provided at a predetermined period in a direction substantially perpendicular to the predetermined plane. A light source unit (210) provided separately from the unit, the light source unit (210) configured to emit changing polarized light; and the light source unit (210) provided integrally with the unit.
A polarizing filter (222) for receiving light emitted from the
A light receiving unit (221) including a light receiving element (224) for receiving light emitted from the light source unit that has passed through the polarizing filter; and removing a DC component from an output signal of the light receiving unit (221) to reduce a zero level. An AC converter (260) that converts the signal into a signal that changes as a center; a zero-cross detection circuit (261) that detects a time point at which the output signal of the AC converter (260) changes beyond the zero level; From the polarization direction of the light emitted from the light source unit (210) at the time when the detection circuit (261) detects the time when the output signal of the AC converter (260) changes beyond the zero level, the predetermined direction is determined. Calculating means for calculating a relative angle of the unit with respect to an initial direction (250). 2. The relative angle detecting device according to claim 1, wherein the light source unit (210) comprises: a light source (213); and a polarizing filter (21) through which light from the light source (213) passes.
5) rotating means (21) for rotating the polarizing filter (215);
8, 219). 3. The relative angle detecting device according to claim 1, wherein the unit is within a predetermined initial angle range with respect to a polarization direction of light emitted by the light source unit (210). Initial angle setting means for instructing; and arithmetic means (250) having an angle register for storing a relative angle detected immediately before, wherein the arithmetic means (250) determines that the unit is in the predetermined initial direction. When instructed, calculate the relative angle of the unit, store the relative angle close to the predetermined initial direction in the calculated relative angle in the angle register, at the time of the relative angle detection operation, among the calculated relative angle, A relative angle detecting device that outputs a relative angle closest to the relative angle stored in the angle register as a detected angle, and stores and updates the detected angle in the angle register. 4. The relative angle detecting device according to claim 1, wherein light other than polarized light from the light source unit (210) is incident on the light receiving unit (221). A relative angle detecting device including a light shielding means for reducing the occurrence of light. 5. The relative angle detecting device according to claim 1, wherein an infrared LED is used as the light source (213). 6. A head mounted display (10) mounted on the head of the user (100) and having image display means for providing images to both eyes of the user (100).
2), and a control unit (70) for generating an image to be displayed on the image display means of the head-mounted display (102), wherein images provided to both eyes of the user (100) have different parallaxes. A virtual reality providing apparatus that provides a user with a three-dimensional image by using the relative angle detecting device according to claim 1, wherein the light is directed downward at an upper part of the user (100). The light source unit (210) is arranged so as to be radiated toward the head unit, and the light receiving unit (221) is arranged so as to be arranged on the head mounted display (102). An image displayed on the image display means can be changed according to a relative angle in a plane perpendicular to the vertical direction of the head mounted display (102) detected by the relative angle detecting device. Virtual reality providing apparatus according to claim. 7. A head-mounted display (10) mounted on the head of the user (100) and having image display means for providing images to both eyes of the user (100).
2), and a control unit (70) for generating an image to be displayed on the image display means of the head-mounted display (102), wherein images provided to both eyes of the user (100) have different parallaxes. A virtual reality providing apparatus that provides a user with a three-dimensional image by using the relative angle detecting apparatus according to claim 3, wherein light is emitted downward to an upper part of the user (100). The light source unit (210) is disposed on the head mounted display (102), and the light receiving unit (221) is disposed on the head mounted display (102). An image displayed on the image display means is changed according to a relative angle in a plane perpendicular to a vertical direction of the head mounted display (102). Sensitive providing apparatus. 8. The virtual reality providing apparatus according to claim 7, wherein the initial angle setting means is a button switch (62), and the user (100) is turned on the button switch (60) in a predetermined direction. 62) A virtual reality providing apparatus that indicates the predetermined initial direction by operating the virtual reality providing apparatus. 9. The virtual reality providing apparatus according to claim 7, wherein light other than polarized light from the light source unit (210) is reduced from entering the light receiving unit (221). A virtual reality providing apparatus provided with a light shielding means. 10. The virtual reality providing apparatus according to claim 9, wherein the light shielding means is a light shielding curtain (115) suspended from the light source unit (210) so as to surround a moving range of the user. ) Is a virtual reality providing apparatus.