JPH08328512A - Head mounting type display device - Google Patents

Abstract

PURPOSE: To enable a user to view the display images of a computer and the external state while wearing an HMD. CONSTITUTION: A detecting means 103 detects the direction and posture of the user's head. A controller 102 controls a shutter 103, a display control circuit 105 and a back light driving circuit 107 according to this detection and changes the respective sizes of the video display part in a display section 109 using a liquid crystal display and the transmissive part of the shutter 103. The shutter 103 is fully shut off of light and the video signals from the computer are displayed on the display section 109 when the user views the front. The display is prohibited and the shutter 103 is fully opened when the user faces downward. An external keyboard 3 is then made visible through a half mirror 110 and the user is able to make key operation. The video display and the keyboard 3 are visible half each if the user faces slightly downward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-mounted display device [hereinafter referred to as HMD (HEAD MOUNTED DISPLA
Y)]].

[0002]

2. Description of the Related Art There have been many HMDs for a long time, for example, Morton L., USA. Stereoscopic-Television by Hefllg
Apparatus for Individual
This has already been shown in Use (USP 2,955,156). In recent years, applications for performing various operations while viewing a display using an HMD have been increasing. For example, an HMD may be used to display a computer. HM
By using D, it is possible to operate the computer at various places without the need for a large CRT display and without the fear of being seen by others.

[0003]

When the conventional HMD is used for the display of the computer, the display and the keyboard cannot be seen at the same time. Therefore, when the keyboard operation is actually required, the HMD is not displayed. There was a problem that I had to remove it each time. Such an operating environment is inconvenient for a person who is skilled in computer operation, for example, a person who is capable of performing blind touch, and can be said to be a very inconvenient use environment for a person who is unfamiliar with computer operation.

Therefore, the present invention has an object to solve the above-mentioned problems in the case where the HMD is used as a computer display. That is, it is an object of the present invention to provide an HMD capable of detecting an operator's willingness to look at a keyboard and correspondingly looking directly at the outside world such as a keyboard.

[0005]

According to the present invention, an image based on a video signal is displayed on a display screen and external light is transmitted therethrough, and the ratio between the image display portion and the external light transmitting portion can be controlled. And a detection means for detecting the orientation of the user's head, the posture of the head of the user, or the position of the head, Display control means is provided for controlling the ratio between the image display portion and the external light transmission portion on the display screen of the display means in accordance with the detection of the detection means.

[0006]

According to the present invention, since the ratio of the image display portion and the external light transmitting portion changes according to the position of the user's head, for example, when the user faces the front, the entire surface is displayed as an image. , When the user is facing downward, the entire surface can be made transparent so that the external keyboard etc. can be seen, and when the user is facing slightly downward, the image display part and the transparent part can be seen in half. . Therefore, the user is
It is possible to see the outside without removing the MD.

[0007]

1 is a block diagram showing a schematic configuration of a computer system using an HMD according to an embodiment of the present invention. In the figure, a portion 1 surrounded by a dotted line is a head mounted display device (HMD) according to the present invention. In the HMD 1, the detection unit 101 detects the position of the device such as the direction and posture. The detection signal is sent to the controller 102, and roughly controls the following three parts. The first is the shutter 103, which controls whether the external light 104 is transmitted or blocked. The second is the display control circuit 105, which controls the video signal 106 from the computer 2,
The display unit 109 controls whether or not to display. The third is a backlight drive circuit 107, which controls lighting / non-lighting of the plurality of backlights 108.

As the display unit 109, a two-dimensional liquid crystal display element or the like is used. A video signal controlled by the display control circuit 105 is added to the display unit 109, and all or part of the video signal is displayed. Also, backlight 1
The light of 08 passes through the display unit 109 and the half mirror 110.
Is reflected by and reaches the eyes 4 of the wearer of the HMD. Also,
The external light 104 limited by the shutter 103 also passes through the half mirror 110 and reaches the eyes 4 of the wearer. The display unit 109, the shutter 103, and the half mirror 110 form a display unit. Reference numeral 3 is a keyboard of the computer 2. In the present invention, all the above three controls are not necessary.

Next, various types of detecting means 101 will be described. [Detection Means for Detecting Head Angle Using Gyro] The azimuth detection means as one of the angle detection means will be described with reference to FIG. This is a method using an angle sensor such as a vibration gyro. In FIG. 2, 200 is a gyro sensor 2
The angle change applied to 01 is schematically drawn, and a voltage proportional to the angular velocity of the displacement is output from the gyro sensor 201 as a detection signal. This gyro sensor 201
Since an offset voltage component is superposed to some extent on the output voltage of the above, it is necessary to pass the detection signal to the high pass filter (HPF) 203 for the purpose of removing this unnecessary component. Furthermore, since the output amplitude of the gyro sensor 201 is very small at present, the detection signal is amplified by the amplification circuit 203 having an appropriate magnification in order to obtain a sufficient amplitude voltage.
Next, the detection signal is applied to the integrating circuit 204 in order to convert the detection signal of the angular velocity into angle information. Integrating circuit 204
Output becomes zero when the initialization signal 206 is input, and then the detection signal 205 corresponding to the angular displacement is output.

FIG. 3 shows an example of an actual circuit configuration, in which the angle detecting means is constructed by an analog circuit. Reference numeral 208 denotes an inverting amplifier circuit composed of an amplifier A201 and resistors R201 and R202. 209 is an amplifier A202 and a resistor R2
03 and a capacitor C201. The output of the amplifier A202 is added to the positive input of the amplifier A201, and the output of the amplifier A201 is added to the resistor R203, so that the HPF202 and the amplifier 203 shown in FIG. 204 is an amplifier A203 and a resistor R20
5, capacitor C202, analog switch SW201
Is an integrator circuit. A detection signal (output voltage) 205 is generated by integrating the voltage applied to the resistor R205. The resistor R205 has a function of returning the output voltage to zero with a predetermined time constant, and a resistor having a large value is used when it is desired to slowly return to the reference state when there is no large change.

The configuration shown above is one system, but in reality, it is almost the case that it is desired to detect a change in two dimensions of the vertical (pitch) direction and the horizontal (yaw) direction. 2 and 2 configurations are required for two systems. In that case, the respective detection axes of the gyro sensor 201 can be detected by arranging the gyro sensor 201 so as to run left and right for vertical detection and vertically for horizontal detection. Further, when it is desired to detect the tilt (roll) direction, one system is further required, and the gyro sensor 201 is arranged so that the detection axis runs in the front-back direction. It should be noted that when an angle change detecting means such as a gyro sensor is used, the rotation cannot be detected because the rotation is detected.

[Detection Means for Detecting Head Detachment Angle Using Angle Sensor] FIG. 4 shows a downswing angle detection means. The left side of the figure shows a principle configuration. The fixed portion 301 of the sensor 305 is hermetically sealed, and inside the fixed portion 301 is a rotating portion 303 that freely rotates around a point 302 as a rotation center.
Is included. Then, the liquid having a slightly high viscosity is fixed to the fixing portion 30.
It fills the gap with 1. A magnet 304 is fixed to a part of the periphery of the rotating unit 303, which serves as a weight, and the position of this weight is always lowered regardless of the posture of the sensor 305 (in the rotation direction along the plane of the drawing). Rotate to come to. This is shown on the right side of FIG.
When the sensor 305 is in a balanced state, the largest output appears in the Hall element A, when tilted to the left, the largest output appears in either Hall element B or C, and when tilted to the right, the Hall element on the opposite side appears. The largest output appears in either. The detection circuit 306 detects the output signal of each Hall element, and evaluates the magnitude of the output signal to obtain the inclination of the sensor 305.

[Detection Means for Detecting Head Distance and Posture with respect to Reference Position Using Magnetic Sensor] FIG. 5 shows the principle of detecting a position using a magnetic sensor. Transmission unit 401
Is composed of coils corresponding to three axes of X-axis, Y-axis, and Z-axis, and a driver 403 controlled by a control circuit 402 supplies a current of a predetermined frequency in a time division manner. As a result, a magnetic field 404 having a pattern corresponding to the axis to be energized is formed around the transmitter 401. The receiver 405 is configured similarly to the transmitter 401, and the magnetic field signals detected by the three coils are transmitted by the transmitter 4.
The detection unit 406 observes the intensity relationship that is uniquely determined corresponding to the relative positional relationship with 01. That is, the relative positional relationship (distance and angle) is obtained from this strength relationship by a predetermined calculation method.

[Detection means by line-of-sight detection] FIG. 6 shows the configuration of an HMD having line-of-sight detection means. The liquid crystal display panel 501, which is a display unit, is a lighting unit (backlight) 5
The light from 02 is transmitted, and this light is further transmitted to the prism 50.
It is configured to pass through 3 and reach the eye 4. The two infrared light emitting diodes 504 arranged side by side illuminate the pupil of the eye 4 with infrared light. The infrared reflected light from the eye 4
The inside of the prism 503 is reflected and the mirror 505 reaches the line-of-sight CCD sensor 506. This line of sight CCD
The two infrared light source images illuminated by the eye 4 are projected on the sensor 506, and the position where the line of sight is focused can be obtained from the positional relationship between these images. 507 is a liquid crystal shutter. The principle of this line-of-sight detection will not be described in detail here, but it is shown in detail, for example, in JP-A-61-272552.

Next, a description will be given of how the user wearing the HMD switches the object viewed through the display unit. The circuit diagram of FIG. 7 is a display / non-display switching circuit, and the waveforms A, B, and C of each part will be described with reference to FIG. A waveform A is an input video signal, which is a normal composite video signal clamped by a clamp voltage. A waveform B is a display / non-display selection signal, which is a signal for selecting display when the first half is 1 and non-display when the second half is 0 in synchronization with the vertical synchronizing signal of the image. The switch SW of the circuit of FIG. 7 is switched by this selection signal, the video signal is transmitted as it is during display, and the non-display signal is transmitted by being clipped by the clamp voltage during non-display, and the video signal of waveform C is generated. It The display state of the display unit at that time becomes an image as shown in FIG. Also, if the display screen is divided into upper and lower parts and the light emission can be controlled separately, and if the backlight emission or non-emission is controlled according to display or non-display, the contrast of the display is improved and power consumption is saved. Also becomes.

[Description of Liquid Crystal Shutter] The left side of FIG. 10 is the same HMD as the structure of FIG. 6, and the configuration of the liquid crystal shutter 507 therein is shown on the right side. In the figure, 801
Reference numerals 802 denote polarizing plates, which have vertical polarization characteristics. Reference numerals 803 and 804 denote liquid crystal plates, which add a charge to make 90-degree polarized light 0 degree. A liquid crystal driver 805 constantly outputs a drive signal 806. Also,
Reference numerals 807 and 808 denote switches, and by transmitting a drive voltage to the liquid crystal plates 803 and 804 as necessary, it is possible to change from a state in which normal light is blocked to a state in which light is transmitted.

The following HMDs according to the present invention can be constructed by combining the above-described components. FIG. 11 is a diagram illustrating a display operation with three configurations of a backlight, a liquid crystal display panel, and a liquid crystal shutter. The backlight can be switched between full lighting, upper half lighting, and full lighting by the backlight drive circuit. In addition, the display panel can be switched between three modes of full display, upper half display, and full display by the display control circuit. The shutter can be switched between full blocking, lower half transparent, and full transparent.

As shown in FIG. 12, the detection results of the downswing angle detecting means correspond to the three posture states of "front view", "slightly downswing", and "pretty downswing". The states are combined into the visible image state as shown at the bottom of FIG. That is, the display screen, for example, the screen of a computer, can be seen in its entirety when viewed from the front. In the "slightly depressed" state, the display is only in the upper half and is transparent in the lower half, and the computer keyboard can be seen, for example. The display is not completely displayed for the "pretty down" state, and the outside world, for example, the keyboard becomes completely transparent. That is, the ratio of the image display portion of the display screen to the external light transmission portion changes according to the position of the user's head.

FIG. 13 shows an embodiment in which the line-of-sight detecting means is used as the detecting means and only the shutter is used in the display section. When the line of sight is in the front (on the left side of the figure), the shutter is in the front blocking state, and the only visible image is the image on the display unit, and nothing can be seen around the image. Gaze down (right side of the figure)
Then, in the shutter, the lower side is in a transmissive state, and the visible image can be seen in addition to the image on the display unit, and the external state can be seen below it. In FIG. 13, a circle cross mark indicates a position where the line of sight is detected.

[0020]

As described above, according to the present invention, when the HMD is used as a display device for various equipment, when the user wants to see something other than the display screen, the display device is in a transparent state depending on the viewing direction. Therefore, unlike the conventional HMD, the inconvenience of having to remove the HMD one by one is solved, and the HMD can be used as a display device for various equipment such as a computer without a feeling of strangeness.

In addition, when operating a certain type of equipment other than a computer, it may be difficult to operate without referring to the operation manual, and both hands may need to be fully used. For example, operations such as assembling and repairing automobiles and the like are performed. In such a case, by using the device according to the present invention, it is possible to see the equipment operation transparently in "front view" so that the corresponding operation manual is displayed when looking up, down, left and right. By setting the above, the above requirement can be achieved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing azimuth detecting means.

FIG. 3 is a circuit diagram showing a circuit configuration example of an azimuth detecting means.

FIG. 4 is a block diagram showing a declination angle detecting means.

FIG. 5 is a configuration diagram showing a magnetic sensor.

FIG. 6 is a configuration diagram showing a line-of-sight detection means.

FIG. 7 is a circuit diagram showing a display / non-display switching circuit.

FIG. 8 is a waveform diagram of each part of FIG.

FIG. 9 is a configuration diagram showing an example of a display state.

FIG. 10 is a configuration diagram showing an HMD using a line-of-sight detection means.

FIG. 11 is a configuration diagram illustrating a display switching operation of each unit of the HMD.

FIG. 12 is a configuration diagram showing a state in which the head wearing the HMD is moved.

FIG. 13 is a configuration diagram showing display switching when line-of-sight detection and a liquid crystal shutter are combined.

[Explanation of symbols]

 1 HMD 101 Detecting Means 102 Controller 103 Shutter 105 Display Control Circuit 107 Backlight Drive Circuit 108 Backlight 109 Display Unit 110 Half Mirror

Claims (8)

[Claims] 1. A display screen is used to display an image by a video signal and to allow external light to pass therethrough, and the ratio between the image display portion and the external light transmitting portion can be controlled and the user's head. Display means that is attachable to the user's body, detection means for detecting the direction in which the user intends to look or the posture or head position of the user's head, and the display according to the detection by the detection means. A head mounted display device comprising a display control means for controlling the ratio of the image display portion and the external light transmission portion on the display screen of the means. 2. The head-mounted display device according to claim 1, wherein the detecting means is a visual line detecting means for detecting a visual line gazing point of the user on the display screen. 3. The head-mounted display device according to claim 1, wherein the detection unit is an angle detection unit that detects an angle due to a change in the direction and posture of the head of the user. 4. The head mounted display device according to claim 3, wherein a gyro is used as the angle detecting means. 5. The head-mounted display device according to claim 1, wherein the detection means includes a magnetic sensor that detects a relative relationship with a reference position by transmitting and receiving a magnetic signal. 6. The head-mounted display device according to claim 1, wherein the display means has a display prohibiting means for restricting input of a video signal to prohibit display of a part or all of the display screen. 7. The head-mounted display device according to claim 1, wherein the display unit has a light blocking unit that blocks a part or all of the external light. 8. The head mounted display device according to claim 1, wherein the display means has a light emission prohibiting means for prohibiting light emission of a part or all of a light source that illuminates a display screen.