WO2012133020A1

WO2012133020A1 - Head-mounted display

Info

Publication number: WO2012133020A1
Application number: PCT/JP2012/057112
Authority: WO
Inventors: 邦宏伊藤; 智己片野
Original assignee: ブラザー工業株式会社
Priority date: 2011-03-30
Filing date: 2012-03-21
Publication date: 2012-10-04
Also published as: JP2012211959A

Abstract

Provided is a head-mounted display for both eyes, which enables required content information to be seen without interruption, while preventing eye fatigue. The head-mounted display for both eyes, which is provided with a display unit for the left eye that projects image light onto the left eye of an observer, and a display unit for the right eye that projects image light onto the right eye of the observer, and displays images by making images corresponding to the image light projected on the left and right eyes visible to the observer, is further provided with a fatigue detection unit capable of independently detecting the degree of fatigue in the left and right eyes of the observer when displaying images, and a control unit for forcibly stopping the display of images by the display unit for the left eye or the display unit for the right eye, on the basis of the detection results from the fatigue detection unit.

Description

Head mounted display

The present invention relates to a binocular head mounted display.

Conventionally, as an example of an information processing apparatus that can reproduce various content data, there is a head-mounted display that allows an observer to visually recognize an image while wearing the head. As such a head-mounted display, there is a binocular head-mounted display in which left and right display units are provided on a support member that can be mounted on the head like glasses and image light is projected to both eyes, respectively (for example, patents) See reference 1.) In addition, as a display device with which a display part is provided, there exists a type which projects the image light from a liquid crystal display device, or a type which projects by projecting a laser beam two-dimensionally, for example.

In the head-mounted display as described above, the observer is always in the state of looking at the image displayed on the display unit, and thus may cause eye strain when used for a long time. Therefore, in Patent Document 1, the control means changes the image corresponding to the passage of the display time.

In other words, over time, for example, by reducing the contrast of the image or increasing the brightness so that the viewer's eyes are tired, it is possible to reduce the user's eye strain. .

JP 2003-076353 A

However, since the technique of Patent Document 1 is designed to make it easy to see an image even if the observer's eyes are tired, the eyestrain of the observer is not reduced, but without knowing it. There was a risk that eye fatigue would accumulate.

On the other hand, for an observer who is viewing an image corresponding to the content information as needed, dissatisfaction remains with control that turns off the power when a predetermined time limit is reached.

In view of the above-described problems, an object of the present invention is to provide a binocular head-mounted display that can view necessary content information without interruption while preventing eye fatigue.

In order to achieve the above object, the head-mounted display of the present invention includes a left-eye display unit that projects image light onto the left eye of the observer, and a right-eye display unit that projects image light onto the right eye of the observer. In the binocular head mounted display that displays the image according to the image light projected on each of the left and right eyes to the observer, when performing the image display, Based on the detection result by the fatigue detection unit capable of independently detecting the fatigue levels of the left and right eyes of the observer, either the left eye display unit or the right eye display unit And a control unit that substantially stops image display by one of the display units.

In the head-mounted display, the control unit may stop the image display by either the left-eye display unit or the right-eye display unit, and then the image display stop state continues for a predetermined time. The image display by the one display unit in the image display stop state may be resumed, and the display stop control for substantially stopping the image display by the other display unit may be repeated a predetermined number of times.

In the head mounted display, the control unit may forcibly stop the image display by the display unit after repeating the display stop control a predetermined number of times.

In the head-mounted display, the control unit restarts the binocular image display by the right-eye display unit and the left-eye display unit of the display unit after repeating the display stop control a predetermined number of times. You may make it do.

In the head mounted display, the control unit may change the number of times the display stop control is repeated according to the content of the image displayed on the display unit.

Further, in the head mounted display, the fatigue detection unit may include an imaging unit that images the observer's eyes and an image analysis unit that analyzes an imaging result of the imaging unit.

Further, in the head mounted display, the fatigue detection unit includes time measuring means capable of individually measuring the image display time by the right eye display unit and the image display time by the left eye display unit of the display unit, Fatigue estimation means for estimating the fatigue state of the left and right eyes of the observer based on the timing results of the timing means.

According to the present invention, in the binocular HMD, the display on one eye judged to be tired is forcibly stopped, so that the necessary image is continuously viewed with the other eye while resting the tired eye. be able to. Therefore, the necessary images can be viewed over a necessary and sufficient time while preventing the observer's eyes from fatigue and other adverse effects caused by fatigue.

It is explanatory drawing which shows the use condition of HMD which concerns on one Embodiment of this invention. It is a block diagram of the HMD. It is a flowchart which shows an example of an eye strain reduction process. It is a timing chart which shows the operating state of the HMD main body controlled by the same eye strain reduction process.

Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings. FIG. 1 is an explanatory diagram showing a head mounted display (hereinafter referred to as “HMD”) according to the present embodiment, and FIG. 2 is a block diagram of the HMD.

[First Embodiment]
As shown in FIG. 1, the HMD according to the present embodiment is a binocular HMD, and the left and right HMD

main bodies

2L and 2R that can be used when the observer 1 is worn on the head, and both the HMD main bodies 2L, And a controller 3 connected to the 2R via a transmission cable 4. Since the left and right HMD

main bodies

2L and 2R have the same configuration, the HMD main body 2 may be simply referred to when the configuration is described below or when both are expressed.

The HMD

main bodies

2L and 2R can each display various content information as images so as to be visible to the observer 1. The controller 3 mainly performs processing for supplying image signals to the left and right HMD

main bodies

2L and 2R. The various content information includes, for example, a moving image file, a still image file, a text file, and the like, and may be stored inside the HMD or stored outside the HMD. .

An image display unit 21 (see FIG. 2) serving as a projection unit composed of a liquid crystal display device is disposed inside the HMD main body 2, and power and image signals are supplied from the controller 3 to the image display unit 21. It is like that. Then, the light of the display image displayed on the image display unit 21 based on the image signal is projected as image light onto the eyes of the observer 1 through an optical system (not shown) and the half mirror 22. Thus, the light incident on the eye is imaged on the retina, so that the viewer 1 can visually recognize an image corresponding to the content information (hereinafter simply referred to as “content”).

That is, the HMD according to the present embodiment is a see-through type that includes a half mirror 22 that reflects and projects image light according to content information to the eyes of the viewer 1 while transmitting external light. . Therefore, even when the HMD is displaying the content, the viewer 1 has the outside world (background) in a region other than the region displaying the content in the field of view of the viewer 1. It can be visually recognized.

In addition, since the HMD according to the present embodiment is a binocular HMD including the HMD

main bodies

2L and 2R, so-called 3D display can be easily performed. In that case, when the image display unit 21 provided in each of the HMD

main bodies

2L and 2R generates an image, an image having parallax is generated so that the viewer 1 can visually recognize the image as a left-eye image and a right-eye image. Good.

As described above, each of the HMD

main bodies

2L and 2R according to the present embodiment performs image display by projecting image light onto the eyes of the observer 1 and causing the observer 1 to visually recognize an image corresponding to the image light. It functions as an eye display unit and a right eye display unit.

Further, as shown in FIG. 1, the HMD

main bodies

2L and 2R are attached to a support member 2a having a substantially glasses shape, and a half mirror 22 is positioned at the front end of each of the HMD

main bodies

2L and 2R. Is installed. Thus, as described above, the external light passes through the half mirror 22 and enters the observer's 1 eye, and the image light corresponding to the content information is reflected by the half mirror 22 and enters the observer's 1 eye.

The HMD also includes an imaging unit for imaging the left and right eyes of the observer 1. In the present embodiment, left and right cameras corresponding to the HMD

main bodies

2L and 2R are provided as the imaging unit, and the degree of eye redness can be detected from images captured by the cameras. In the present embodiment, the left and right cameras are fatigue detection devices 23 (see FIG. 2), and function as part of a fatigue detection unit that detects fatigue of the eyes of the observer 1. The left and right cameras may be attached to a position facing the left eye in the HMD main body 2L if the camera is for the left eye, and attached to a position facing the right eye in the HMD main body 2R if the camera is for the right eye.

Further, the controller 3 is provided with a control circuit including a CPU 33 capable of supporting both the HMD

main bodies

2L and 2R, a memory such as a

ROM

34, 35, and a RAM 36 in a rectangular box-shaped casing 30. Such a control circuit functions as a control unit of the HMD. The controller 3 includes a power source such as a battery (not shown).

The control circuit including the CPU 33 is a main part of the present embodiment, and based on the detection result by the fatigue detection device 23, the HMD main body 2L that is the left-eye display unit or the HMD main body that is the right-eye display unit. Display stop control for substantially stopping image display by any one of the HMD main bodies 2 of 2R is performed. That is, the control circuit also functions as an image analysis unit that analyzes the imaging results of the left and right cameras, which are imaging units, and functions as a fatigue detection unit together with the left and right cameras (fatigue detection device 23). Note that, as display stop control for substantially stopping image display by the HMD main body 2, in this embodiment, control for forcibly turning off the display is performed. However, the display stop control includes a case where the brightness of the display image is lowered to a predetermined value or less and the display image is darkened to such an extent that the display image is hardly visible. The eye fatigue reduction process, which is a specific process of the display stop control, will be described in detail later.

Further, a power switch 31 and a power lamp 32 are provided on one surface of the casing 30 of the controller 3. The controller 3 and the HMD body 2 are connected by a transmission cable 4 composed of a plurality of signal lines. In this embodiment, the controller 3 and the HMD main body 2 are separated into a left signal line 4L and a right signal line 4R, and these are bundled together. The transmission cable 4 is used. A left plug 4LP and a right plug 4RP are provided at the ends of the

transmission cables

4L and 4R, and can be independently connected to left and right jacks provided on the upper end surface of the casing 30 of the controller 3.

Here, the electrical configuration of the controller 3 will be described with reference to FIG. As shown in the figure, the controller 3 includes a CPU 33 as an arithmetic processing unit, and a program ROM 34, a flash ROM 35, a RAM 36, an image processing unit 37, a timer 38, a video RAM 39, an interface (interface) connected to the CPU 33 via a bus. I / F) 40, 41, and an off mode switch 42 are provided.

The program ROM 34 stores various information processing programs such as a program for realizing a function as an HMD and a program for performing an eye strain reduction process when eye fatigue of the observer 1 is detected.

Then, by executing these programs, the CPU 33 operates various circuits constituting the HMD, executes various functions provided in the HMD, and functions as a control unit that performs overall control of the entire operation of the HMD. The CPU 33 also controls the drive timing of the fatigue detection device 23, and after the HMD is activated, the camera which is the fatigue detection device 23 is used to capture the image of the observer 1 at a predetermined interval.

Further, the flash ROM 35 stores various data including image data including content information and an HMD stop time table used for eye strain reduction processing. The RAM 36 is used as a work area.

In the HMD stop time table stored in the flash ROM 35, as will be described in detail later, dominant data, HMD stop time data, stop count data, content content type data, and the like are associated with each other. In this embodiment, when eye fatigue is detected, the display stop process for stopping image display by either the left eye display unit or the right eye display unit is repeated a predetermined number of times, and fatigue is detected. The stop time of image display by the HMD main body 2 varies depending on whether or not the eyes are dominant.

The flash ROM 35 also stores reference image analysis data indicating the degree of redness of the eye, which is a reference for the fatigue level. The CPU 33 analyzes the captured image from the camera that is the fatigue detection device 23 and determines the fatigue level that requires a break by comparing the analysis data obtained by the analysis with the stored reference image analysis data. Like to do.

Also, the image processing unit 37 functions exclusively for image processing for displaying content in cooperation with the video RAM 39.

The timer 38 measures the operation time from when the HMD is started until it is stopped, the stop time of the HMD main body 2 (from stop to return), and the like. The timer 38 displays the image display time by the HMD main body 2L and the HMD main body 2R, respectively. It can be measured individually.

The interfaces (I / F) 40 and 41 include the HMD connection I / F 40 that performs a connection function with the HMD main body 2, the fatigue detection device (for example, the camera) 23, the power switch 31, and the power lamp 32. There is a peripheral I / F 41 that performs a connection function. Note that the image data corresponding to the content displayed by the image processing unit 37 is also stored in advance in the flash ROM 35 as described above, but may be sequentially input from the outside.

The off-mode switch 42 is a switch that automatically turns off the power after the eye strain reduction process described later is performed. That is, normally, after the eye strain reduction process is performed, it is allowed to return to the binocular display and continue to observe the content. However, when the off-mode switch 42 is operated, a predetermined time elapses. Then the power is automatically turned off.

Here, when using the HMD according to the present embodiment, an eye strain reduction process performed when the fatigue detection unit detects eye fatigue of the observer 1 will be described. In the eye strain reduction process according to the present embodiment, the left and right cameras, which are the fatigue detection devices 23, image the left and right eyes of the observer 1 at a predetermined timing, and the CPU 33 analyzes the captured image. That is, while using the HMD, the eyes of the observer 1 become congested due to fatigue. By analyzing the images taken periodically, it detects the hyperemia state of the eye that appears in the image, determines whether the left or right side is more tired, and corresponds to the eye that is determined to be tired The display by the HMD body 2 is forcibly stopped, and the content is visually recognized by the opposite eye while resting the eyes determined to be fatigued.

Therefore, even content information that needs to be displayed for a long time, such as a movie, can be viewed to the end without interrupting the display of the image, and eye fatigue is reduced as much as possible. be able to.

Further, in the present embodiment, after the image display by the image display unit 21 of either the HMD main body 2L or the HMD main body 2R is stopped, when the image display stop state continues for a predetermined time, the one of the image display stop states. While the image display by the HMD main body 2 is resumed, the display stop control for forcibly stopping the image display by the other HMD main body 2 is repeated a predetermined number of times.

Hereinafter, the eye strain reduction process will be specifically described with reference to FIG. FIG. 3 is a flowchart showing eye strain reduction processing.

When the HMD is turned on and content display is started, as shown in FIG. 3, the CPU 33 of the control circuit activates the fatigue detection device 23 (step S11). In this manner, the CPU 33 functions as a fatigue detection unit together with the camera that is the fatigue detection device 23, and executes analysis of an image captured by the camera at regular intervals.

Analytical data obtained by analyzing the degree of redness of the left and right eyes of the observer 1 is stored in the RAM 36. When this process ends, the CPU 33 shifts the process to step S12. Prior to the activation process of the fatigue detection device 23, the CPU 33 executes RAM access permission, initialization of a work area, and the like.

The CPU 33 first detects the degree of fatigue of the right eye of the observer 1 based on the analysis data of the captured images relating to the left and right eyes stored in the RAM 36 and the reference image analysis data stored in the flash ROM 35 ( Step S12). If it is determined that the fatigue level of the right eye of the observer 1 has reached a predetermined fatigue level (step S12: YES), the CPU 33 moves the process to step S14. On the other hand, if it is determined that the fatigue level of the right eye has not yet reached the predetermined fatigue level (step S12: NO), it is then determined whether the fatigue level of the left eye has reached the predetermined fatigue level ( Step S13). If it is determined that the fatigue level of the left eye of the observer has not reached the predetermined fatigue level (step S13: NO), the right eye fatigue level is detected again based on new analysis information after a predetermined time has elapsed. Do. If it is determined in step S13 that the degree of fatigue of the left eye has reached a predetermined fatigue level (step S13: YES), the CPU 33 moves the process to step S14.

In step S <b> 14, the CPU 33 sets a flag for defining the display stop control repetition count a in the RAM 36. As a first flag, n = 0 is set, thereby storing a detection result that either the right eye or the left eye is tired.

The number of repetitions a is specified within a range of about 1 to 10 times, and the setting of the number of repetitions can be arbitrarily changed. For example, it can be changed according to the content of the content to be displayed. That is, when the content is a moving image, the eyes are likely to get tired, so it can be set to 6 to 10 times, for example, and if the content is a movie, it can be set to 10 times. Further, when the content is a still image, it is considered that the eyes are relatively hard to get tired. Therefore, the content can be set, for example, 1 to 5 times.

In step S15, the CPU 33 determines whether there is no problem in viewing the currently displayed content with one eye. For example, if one side displays an image of some object and the other side is an image of a text description of the object, the left and right HMD main bodies 2 display different images, which is not suitable for one eye. It will be judged. In this process, when it is determined that the content to be displayed is not suitable for one eye (step S15: NO), the CPU 33 moves the process to step S16, and when it is determined that the content is suitable for one eye (step S15: YES), The process moves to step S17.

Next, in step S <b> 17, the CPU 33 determines whether or not the eye that has detected fatigue is a dominant eye based on the HMD stop time table stored in the flash ROM 35. Regarding the dominant eye, the observer 1 can register in advance, and the registered dominant eye data is set in the HMD stop time table.

If it is determined that the eye is not dominant (step S17: NO), the driving of the image display unit 21 of the HMD main body 2 that is displaying an image on the eye that has detected fatigue is stopped for 10 minutes (step S18). That is, a break time of 10 minutes is forcibly given. On the other hand, if it is determined that the eye is dominant (step S17: YES), the driving of the image display unit 21 of the HMD main body 2 that is displaying an image on the eye that has detected fatigue is stopped for 5 minutes (step S19). That is,
Force a 5 minute break. In this way, the difference in rest time is because the dominant eye is less tired and the non-dominant eye is more likely to get tired, so the eye rest time when not being dominant is increased. .

By the way, in step S16 when it is determined in step S15 that the content to be displayed is not suitable for one eye, the CPU 33 determines whether or not the content has been switched.

When it is determined that there is no content switching (step S16: NO), the CPU 33 moves the process to step S23, and when it is determined that there is content switching (step S16: YES), the CPU 33 performs the processing step. Return to S14.

After step S18 and step S19, the CPU 33 sets n + 1 in the RAM 36 (step S20), and then determines whether n = a (step S21).

If it is determined that n = a is not satisfied (step S21: NO), the HMD main body 2 to be stopped and displayed is replaced, and the process returns to step S17 (step S22). That is, in step S22, the HMD main body 2 that stops image display is replaced with the HMD main body 2 that has been displaying images. On the other hand, if it is determined that n = a (step S21: YES), the CPU 33 shifts the processing to step S23. That is, this time, the drive of the image display unit 21 of the HMD main body 2 that has been displaying images is stopped. Thus, the display stop control is repeated up to a predetermined number of times between the HMD main body 2L and the HMD main body 2R.

In step S23, the CPU 33 determines whether or not the off mode is selected. Here, the off mode is a mode in which the power is automatically turned off after a lapse of a predetermined time after the display stop control is completed, and the mode is shifted by the operation of the off mode switch 42 provided in the controller 3. If it is not selected to shift to the off mode, after the display stop control is finished, the display returns to the normal display in which the images are displayed for both eyes, and the content can be continuously observed. Even when the content is unsuitable for one eye, normal display for displaying an image for both eyes is continued.

That is, when the off mode is selected (step S23: YES), the CPU 33 sets a power-off timer in the RAM 36 (step S25), and thereafter ends the eye strain reduction process. As a result, the power is automatically turned off after a predetermined time has elapsed.

On the other hand, when the off mode is not selected (step S23: NO), the CPU 33 shifts to the continuation mode and drives the image display units 21 of the HMD

main bodies

2L and 2R to display both eyes (step S24). This eye strain reduction process is terminated.

As described above, according to the present embodiment, in the binocular HMD capable of so-called 3D display, the content information that should not be interrupted is unilaterally while resting one of the eyes. Can be observed. Since the observer 1 can determine whether to resume the observation with both eyes again or to take a full rest, it can be said that the HMD is easy to use for the observer 1.

Next, the eye strain reduction process described above will be described with reference to the timing chart of FIG. Here, it is assumed that the display stop control repetition number a described in step S14 in FIG. 3 is 1 (n = a = 1). That is, the display stop control by the eye strain reduction process is not repeated alternately between the HMD main body 2L and the HMD main body 2R, but only the display stop control of the HMD main body 2 corresponding to the eye on which fatigue is detected. Is performed each time.

When the power is turned on to the HMD, as shown in FIG. 4, the left and right HMD

main bodies

2L and 2R are activated together, and content display for both eyes is started. At the same time, the left and right eyes are imaged by the camera, and the captured image is analyzed (see step S11 to step S13 in FIG. 3).

At the time of (A), for example, when fatigue of the right eye is detected (see step S12 in FIG. 3), the content of the content at this time is also suitable for display with one eye (single-eye display is possible). Therefore, the driving of the image display unit 21 of the HMD 2R for the right eye is stopped (right eye display off). The stop time at this time is 5 minutes if the right eye is dominant, and 10 minutes if the right eye is not dominant (see steps S15 to S19 in FIG. 3).

Thereafter, at the time of (B), the display returns to the binocular display (see step S24 in FIG. 3). At this time, it is estimated that the fatigue of the right eye has recovered to some extent.

When a certain period of time has passed, the left and right eyes are imaged again by the camera, and the captured image is analyzed. This time, it is assumed that fatigue of the left eye is detected at the time point (C) (step S13 in FIG. 3). See). Since the content at this time is also suitable for display with one eye (one-eye display is possible), the driving of the image display unit 21 of the left-eye HMD 2L is stopped (left-eye display off). The stop time at this time is also 5 minutes if the left eye is dominant, and 10 minutes if the left eye is not dominant (see steps S15 to S19 in FIG. 3).

After that, at the time of (D), it returns to the binocular display. At this time, it is estimated that the fatigue of the left eye has recovered to some extent.

Suppose that the content changes to a content unsuitable for single-eye display while the binocular display of the content continues. In such a state, it is assumed that fatigue of the right eye is detected at time (E) (see step S12 in FIG. 3). Since the content at this time is unsuitable for display with one eye, the control circuit waits until the one-eye display is switched. If it demonstrates with the flowchart of FIG. 3, the binocular display of step S24 will be maintained.

Then, at the time of (F) when the content is suitable for one-eye display (one-eye display is possible), the drive of the image display unit 21 of the right-eye HMD2R is stopped (right-eye display off). . At this time as well, a break of time according to whether it is dominant or not dominant will be given.

By the way, for example, when the left eye is dominant, the drive of the image display unit 21 of the HMD2R is stopped for 10 minutes from the time point (F) (the right eye is rested for 10 minutes). On the other hand, when the camera (fatigue detection device 23) that functions as a part of the fatigue detection unit operates every 5 minutes to pick up an eye, for example, the left eye fatigue is detected at time (G). Cases are also conceivable. That is, the detection result that the left eye is tired based on the analysis data of the captured image stored in the RAM 36 and the reference image analysis data stored in the flash ROM 35 may be stored in the RAM 36 while the HMD 2R is stopped. is there.

However, at the time of (G), the HMD2R is still stopped. That is, since the series of eye strain reduction processing has not been completed, the CPU 33 does not immediately stop driving the image display unit 21 of the HMD 2L.

Then, the eye strain reduction process proceeds, the display shifts to the binocular display in step S24 in the flowchart shown in FIG. 3 (the eye strain reduction process ends), and a new eye strain reduction process is performed at time (H). For the first time, the driving of the image display unit 21 of the HMD 2L is stopped (left-eye display off).

[Other Embodiments]
By the way, in embodiment mentioned above, in order to determine fatigue | exhaustion of the left eye or the right eye, the eye of the observer 1 is imaged with the camera which is the fatigue detection device 23, and eye fatigue is detected from the degree of redness of the eye. It was. However, eye fatigue may be detected by the measurement time by the timer 38 without using a camera.

That is, the timer 38 is configured to be able to individually measure the image display time by the HMD main body 2R and the image display time by the HMD main body 2L, and based on the time measurement result by the timer 38, the left and right eyes of the observer 1 The control circuit having the CPU 33 or the like is provided with a function as a fatigue estimation means for estimating the fatigue state. Therefore, the fatigue detection unit in this case is configured to include the timer 38 and the control circuit.

As described above, if the fatigue of the eye of the observer 1 is detected based on the length of the image display time measured by the timer 38, the timer 38 can be used as the fatigue detection device 23, and a warning display table or the like. And the processing load on the CPU 33 is reduced. Therefore, reduction of development load, cost reduction, and improvement of HMD processing speed can be expected.

From the embodiment described above, the following HMD (head mounted display) is realized.

(1) HMD2L (display unit for left eye) that projects image light to the left eye of the observer 1 and HMD2R (display unit for right eye) that projects image light to the right eye of the observer 1 When the image display is being executed in the binocular HMD that causes the person 1 to visually recognize the image according to the image light projected on the left and right eyes and display the content (image display) Based on the fatigue detection part (for example, CPU33 and fatigue detection device 23 (camera) of a control circuit) and the detection result by this fatigue detection part which can detect each fatigue degree of the right and left eyes of the person 1 independently, HMD provided with the control part (for example, CPU33 of a control circuit) which stops substantially the image display by any one of HMD2L or HMD2R.

According to such an HMD, necessary content can be viewed without interruption while preventing eye strain. Therefore, it is possible to safely observe content that does not want to be interrupted during observation, and eye fatigue can be suppressed as much as possible. For example, even content information that needs to be displayed for a long time, such as a movie, can be viewed to the end without interrupting image display.

(2) In the HMD of (1), the control unit (for example, the CPU 33 of the control circuit) displays either one of the HMD2L (left eye display unit) or the HMD2R (right eye display unit). After the image display by the unit 21 (projection unit) is stopped, when the image display stop state continues for a predetermined time, the image display by the one HMD 2 (display unit) in the image display stop state is restarted and the other HMD 2 HMD that repeats display stop control for substantially stopping image display a predetermined number of times.

According to such an HMD, it is possible to continue contention observation while allowing a single eye to take a break.

(3) In the HMD of (2), the control unit (for example, the CPU 33 of the control circuit) forcibly stops the image display by the HMD2 (display unit) after repeating the display stop control a predetermined number of times. HMD.

Such an HMD can sufficiently recover eye fatigue while continuing to observe content to some extent.

(4) In the HMD described in (2) above, the control unit (for example, the CPU 33 of the control circuit) repeats the display stop control a predetermined number of times, and then the HMD2R (right-eye display) of the HMD2 (display unit). Part) and the HMD which resumes the image display for both eyes by the HMD2L (the display part for the left eye).

According to such an HMD, it is possible to observe content for a long time while recovering eye fatigue to some extent.

(5) In any one of the above HMDs (2) to (4), the control unit (for example, the CPU 33 of the control circuit) sets the number of times a to repeat the display stop control to the content content (HMD2 (display unit)). The HMD is changed according to the content of the image displayed on the screen.

According to such an HMD, an appropriate eye break time can be given depending on the content to be observed, so that the possibility of lack of breaks and excessive breaks can be reduced as much as possible.

(6) In the HMD of any one of (1) to (5), the fatigue detection unit (for example, the CPU 33 and the fatigue detection device 23 of the control circuit) is a camera (imaging unit) that images the eyes of the observer 1 ) And a control circuit (image analysis unit) that analyzes the imaging result of the camera.

According to such an HMD, it becomes possible to more reliably determine eye fatigue from the degree of eye redness.

(7) In the HMD according to any one of (1) to (5), the fatigue detection unit includes the image display time of the HMD2R (display unit for right eye) of the HMD2 (display unit) and the HMD2L (left A timer 38 (time measuring means) capable of individually measuring the image display time by the eye display unit) and a fatigue estimation means for estimating the fatigue state of the left and right eyes of the observer 1 based on the time measurement result by the timer 38 HMD provided with.

According to such HMD, the timer 38 can be used also as the fatigue detection device 23, the capacity of the alert display table and the like is reduced, and the processing load by the CPU 33 is reduced. Therefore, reduction of development load, cost reduction, and improvement of HMD processing speed can be expected.

Although the embodiments of the present invention have been described in detail with reference to the drawings, these are merely examples, and various modifications and improvements can be made based on the knowledge of those skilled in the art, including the aspects described in the summary section of the invention. It is possible to implement this invention in the other form which gave. For example, the HMD to which the present invention is applied is, for example, a see-through type HMD, but may not be a see-through type. In addition, a liquid crystal display device is used as a display device for displaying content. For example, by scanning and emitting light modulated according to an image signal related to an image, the retina of at least one eye of the user is emitted. It may be a retinal scanning HMD that projects an image and displays the image. The HMD is preferably provided with an earphone type speaker for generating voice and music.

In the above-described embodiment, the controller 3 is provided with the off-mode switch 42. When the off-mode switch 42 is not operated, the mode is automatically switched to the continuous mode and the binocular display is performed. Even if the switch 42 and the like are not provided, the stop control may be forcibly performed after the display stop control is repeated a predetermined number of times. Further, a continuous mode switch may be provided in the controller 3 in place of the off mode switch 42 so that the power is automatically turned off unless the continuous mode switch is operated. In addition, after the display stop control is repeated a predetermined number of times, the display is not suddenly stopped, but for example, the fatigue level is raised (based on a state where the degree of hyperemia of the eye is higher), and again the fatigue detection device 23 is activated to detect fatigue, and when fatigue is newly detected, control to forcibly turn off the power can also be performed. It should be noted that a display for notifying the stop is preferably performed before the display is stopped.

Further, instead of forcibly turning off the power, for example, a display prompting the stop may be performed after the display stop control is repeated a predetermined number of times so that the observer 1 stops the display.

Further, when the eye fatigue of the observer 1 is detected, the degree of redness of the eye is analyzed, but the fatigue can also be detected based on the interval between eye blinks. In addition, the fatigue detection unit 23 may be configured by providing a sensor for detecting the state of the eyelids of the left and right eyes of the observer 1 and the surrounding muscles instead of or in addition to the camera.

1 observer 2L left HMD body (left eye display)
2R Right HMD body (right eye display)
3 Controller 21 Image display unit (projection unit)
23 Fatigue detection device 33 CPU
38 Timer (time measuring means)
42 Off mode switch

Claims

A left-eye display unit that projects image light onto the left eye of the observer, and a right-eye display unit that projects image light onto the viewer's right eye; In a binocular head mounted display that visually displays an image according to the image light,
A fatigue detection unit capable of independently detecting the degree of fatigue of each of the left and right eyes of the observer when performing the image display;
Based on the detection result by the fatigue detection unit, a control unit that substantially stops image display by either the display unit for the left eye or the display unit for the right eye,
A head-mounted display comprising:
The controller is
After the image display by the projection unit of either the left eye display unit or the right eye display unit is stopped and the image display stop state continues for a predetermined time, the one display unit in the image display stop state 2. The head mounted display according to claim 1, wherein the display stop control for restarting the image display and substantially stopping the image display by the other display unit is repeated a predetermined number of times.
The controller is
The head mounted display according to claim 2, wherein after the display stop control is repeated a predetermined number of times, the image display by the display unit is forcibly stopped.
The controller is
3. The head mount according to claim 2, wherein after the display stop control is repeated a predetermined number of times, the binocular image display by the right eye display unit and the left eye display unit of the display unit is resumed. display.
The controller is
The head mounted display according to claim 2, wherein the number of times the display stop control is repeated is changed according to the content of an image displayed on the display unit.
The fatigue detection unit
An imaging unit for imaging the eyes of the observer;
An image analysis unit for analyzing the imaging result of the imaging unit;
The head mounted display according to claim 1, further comprising:
The fatigue detection unit
Time measuring means capable of individually measuring the image display time by the display unit for the right eye of the display unit and the image display time by the display unit for the left eye;
Fatigue estimation means for estimating the fatigue state of the left and right eyes of the observer based on the time measurement result by the time measurement means,
The head mounted display according to claim 1, further comprising: