JP2007104036A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust the imaging angle of a camera automatically for providing an appropriate image according to the taste of each user. <P>SOLUTION: A display device comprises an imaging means for imaging an image in the direction of an observer's line of sight; a projection means for converting a video signal obtained by the imaging means to an optical image for projection; an eye-piece optical means for guiding the optical image from the projection means to the pupils of an observer; a support means for supporting the imaging means nearly at the same position as the pupils of the observer; and an adjustment means for adjusting the optical axis direction of the imaging means to a direction for forming a depression angle to a horizontal surface passing through the observer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device, and in particular, in a display device including an eyepiece optical system that guides an optical image in front of an eye from an image signal acquired from an image capturing unit that captures an image in a line of sight, a range in which the image capturing unit captures an image is preferable. The present invention relates to a display device that adjusts to the above.

2. Description of the Related Art Conventionally, there are known display devices that are attached in a clip-on manner to a suspension device that is suspended on a head or the like, or a frame of glasses, and that guides an image to a pupil from a small monitor disposed in front of the user's eyes. This is a body-mounted display device called a so-called head mounted display (hereinafter referred to as “HMD”) or a wearable display. HMDs are broadly classified into sealed HMDs whose main purpose is to watch movies and television broadcasts by almost completely blocking the external field of view, and HMDs that display images superimposed on the user's external field of view. can do.
Among these, the HMD of the type that superimposes the video is used as a visual assistance device for patients with eye diseases and persons with impaired eyes because it can provide auxiliary video information in addition to the normal field of view of the user. ing. In recent years, as disclosed in Patent Document 1, for example, an HMD that mounts a small camera on the HMD and captures an image in the field of view and displays the image on the display has been developed, and the role of the HMD as a visual assistance device is increasing. It is increasing.
Japanese Patent Laid-Open No. 10-20997

  When an HMD with a camera is used as a visual assistance device, an image displayed on a small monitor is a substitute for an actual field of view, so that the display range is preferably closer to the actual field of view. Inventors and others show that, when walking, it is best to display an image about 3 to 5 meters ahead in the traveling direction rather than displaying an image of the user's foot on the display part of the HMD. The experimental results were found. In particular, as shown in FIG. 10, it is preferable that a curb of the road is further displayed in the area displayed by the HMD. This is because the user can recognize where he / she is located by using this curb as a landmark. If you simply want to display the curb on the road, you can increase the camera field of view, but if you increase the field of view, the image displayed on the display will become smaller and look worse, especially when walking. There is a problem that its use is restricted. In order to make the image displayed on the display unit suitably recognizable, it is necessary to limit the camera angle of view to some extent. In order to keep the size of the image displayed on the display unit, that is, the camera angle of view constant and to display a suitable image during walking, the imaging direction of the camera, that is, the angle of the optical axis of the camera may be adjusted.

  However, if the angle of the optical axis is uniform, the imaging range is greatly affected by the height of the camera. The height for each user is also very different, and it is said that manufacturing an HMD in which the angle of the optical axis is set for each height (for example, 10 Cm unit) where the HMD is located has a large cost burden and distribution burden and lacks versatility. There is also a problem. Furthermore, even if an HMD is manufactured in which the angle of the optical axis is set for each height at which the HMD is positioned, the set angle is not necessarily an imaging range that provides a suitable image due to user preference or the like. There is a problem that is not limited.

  An object of the present invention is to automatically adjust the imaging angle of a camera in order to provide a suitable video according to the preference of each user.

In order to solve the above-mentioned problem, the invention described in claim 1
An imaging unit that captures an image of the observer's line of sight, a projection unit that converts and projects an image signal obtained by the imaging unit into an optical image, and an optical image from the projection unit is applied to the pupil of the observer In a display device comprising eyepiece optical means for guiding,
Support means for supporting the imaging means at substantially the same position as the pupil of the observer;
And adjusting means for adjusting an optical axis direction of the imaging means to a direction forming a depression angle with respect to a horizontal plane passing through the observer.

The invention according to claim 2 is the display device according to claim 1,
The adjusting means is
A drive means provided at a connecting portion between the support means and the imaging means, and for causing the imaging means to move up and down with respect to a horizontal plane passing through the observer;
An angle detecting means for detecting an elevation angle formed between the imaging means and the horizontal plane in the optical axis direction;
Storage means for storing a predetermined reference elevation angle;
A comparison means for comparing the elevation angle detected by the angle detection means with the reference elevation angle and detecting the difference angle;
The drive means is provided with a control means for outputting an instruction signal for correcting the optical axis direction of the imaging means to the drive means based on the difference angle obtained by the comparison means.

According to a third aspect of the present invention, in the display device according to the second aspect,
When the difference angle is detected by the comparison means, it further comprises warning means for warning that the reference elevation angle and the angle of the imaging means in the optical axis direction do not match.

The invention according to claim 4 is the display device according to claim 2 or 3,
The angle of view of the image pickup means is θ, the height of the image pickup means from the ground is L, and the minimum distance from the point of intersection with the ground to the image pickup range captured by the image pickup means when the perpendicular is dropped from the image pickup means is Dmin. When the vertical direction of the image pickup means is 0 ° and the horizontal plane is 90 °, the angle φ in the optical axis direction of the image pickup means is specified by the following formula (1) and stored in the storage means as the reference elevation angle An angle calculating means for storing is further provided.

The invention according to claim 5 is the display device according to any one of claims 2 to 4,
A moving speed detecting means for detecting the moving speed of the observer;
And a time angle setting means for storing the elevation angle in the optical axis direction of the imaging means as the reference elevation angle in the storage means based on the arrival time to the imaging range imaged by the imaging means. .

The invention according to claim 6 is the display device according to claim 5,
When the height of the imaging means from the ground is L, the moving speed detected by the moving speed detecting means is v, the arrival time is t, the vertical direction of the imaging means is 0 °, and the horizontal plane is 90 ° The time angle setting means specifies the angle φ of the image pickup means in the optical axis direction by the following mathematical formula (2), and stores it in the storage means as the reference elevation angle.

The invention according to claim 7 is the display device according to any one of claims 1 to 6,
The eyepiece optical means transmits external light and displays the image superimposed on the external visual field.

The invention according to claim 8 is the display device according to any one of claims 1 to 7,
The eyepiece optical means includes a prism for guiding an optical image projected from the projection means;
And a hologram element for connecting a virtual image of an optical image guided by the prism to a pupil.

  According to the first aspect of the present invention, by providing the adjusting means for adjusting the optical axis direction of the imaging means in a direction that makes a depression angle with respect to the horizontal plane passing through the observer, an image can be displayed with the optical axis parallel to the horizontal plane. The imaging range can be captured from a range closer to the observer as compared to a display device including an imaging unit for capturing. This makes it possible to provide the observer with an image in a range that is particularly required during walking, and it is more effective to use as a visual aid.

According to the invention described in claim 2, in the display device according to claim 1,
The drive means for raising and lowering the imaging means relative to the horizontal plane, the angle detection means for detecting the angle of the optical axis of the imaging means, and the angle detected by the angle detection means and the reference elevation angle stored in the angle storage means are compared. The angle of the optical axis of the imaging means is further provided by a comparison means for detecting the difference angle and a control means for outputting an instruction signal for correcting the optical axis direction of the imaging means to the driving means based on the difference angle. Even if it changes due to inadvertent contact or the like, there is an effect that it can be automatically adjusted to a suitable imaging angle.

According to the invention of claim 3, in the display device of claim 2,
When the difference angle is detected by the comparison unit, the optical axis direction is further provided with a warning unit that warns that the reference elevation angle stored in the storage unit and the angle of the imaging unit detected by the angle detection unit do not match. It is possible to warn the user of the angle deviation.

According to the invention described in claim 4, in the display device according to claim 2 or 3,
If Dmin, which is the minimum distance to the imaging range, and the imaging field angle θ of the imaging means are set uniformly, the angle φ in the optical axis direction can be uniformly determined by the height L of the imaging means. Thereby, there exists an effect that the angle of the optical axis direction which catches the image | video according to a user's height difference and preference can be acquired easily. Furthermore, it is not necessary to prepare a large number of manufacturing standards for the imaging means according to the height of each user, and there is an effect that it is possible to provide a display device that can display a suitable image while suppressing the manufacturing cost burden.

According to the invention described in claim 5, in the display device according to any one of claims 2 to 4,
The reference elevation angle can be adjusted based on the moving speed of the observer and the arrival time to the imaging range. In particular, when the moving speed is fast, for example, when the observer runs, the image desired by the observer tends to be an image in a range ahead of the imaging range during walking. This is to realize the risk prediction earlier. In the invention of claim 5, since the reference elevation angle is adjusted based on the moving speed and the arrival time to the imaging range, it is possible to automatically provide an image of a desired imaging range when the observer runs, There is an effect that the practicality as a visual assistance device in daily life is surely improved.

  According to the sixth aspect of the present invention, in the display device according to the fifth aspect, the image pickup means is set based on the automatically detected moving speed v only by setting the arrival time t to the image pickup range desired by the observer. The angle in the optical axis direction can be automatically calculated and adjusted.

According to the invention described in claim 7, in the display device according to any one of claims 1 to 6,
Convenience as a visual assistance device is further improved by using an external light transmission type device that transmits external light to the eyepiece optical means and superimposes and displays the image on the external visual field.

According to the invention described in claim 8, in the display device according to any one of claims 1 to 7,
The eyepiece display means uses a prism that guides the light projected from the projection means and a hologram optical element that forms a virtual image on the pupil from the light guided by the prism, so that observation can be performed in the direction of the observer's line of sight. The obstructing element can be eliminated, and there is an effect of securing a better field of view as an auxiliary visual means.

Next, the best mode for carrying out the present invention will be described with reference to the drawings.
In this embodiment, as shown in FIG. 2, the description will be made using the HMD 1 that employs an external light transmissive display mechanism using a hologram optical element. However, the present invention is not limited to this, and the image light flux The present invention is sufficiently applicable to an HMD that uses a half mirror as a mechanism for guiding the light to the pupil and an HMD in which a small liquid crystal monitor that does not transmit external light is arranged in the viewing direction.
In addition to the display unit shown in FIG. 2 integrally formed with the lens unit 41 of the spectacles, the present invention can be applied to various types such as a clip-on configuration for normal spectacles. Can be configured.
In the following description, the eyepiece direction is the front of the HMD 1.

  As shown in the block diagram of FIG. 1, the HMD 1 includes a control unit 2 and a display unit 3. The display unit 3 is provided integrally with the glasses (see FIG. 2), and is connected to the control unit 2 via the cable 19. The control unit 2 includes a control unit 4, a display driver 10, a DSP (Digital Signal Processor) 11, a servo motor control circuit 12, an angular position determination circuit 13, a vibration speed determination circuit 14, a sound source LSI 15, a vibration motor drive circuit 16, and a storage unit. 8 and an operation unit 9 and a battery 29 as a power source.

  The control unit 4 includes a CPU (Central Processing Unit) 5, a ROM (Read Only Memory) 6, and a RAM (Random Access Memory) 7. The CPU 5 expands an operation program stored in the ROM 6 in advance and various application programs stored in the storage unit 11 in the RAM 7 as a work area, and in accordance with the instructions of these programs, an automatic angle adjustment mode and a speed corresponding adjustment described later. Performs overall control including mode processing.

  The ROM 6 includes a nonvolatile memory such as a PROM (Rprogrammable ROM) or a hard disk. An operation program is stored in advance. The RAM 7 is composed of a semiconductor storage element such as an EEPROM (Electrical Erasable Programmable ROM). It is a work area where operation programs and application programs are developed, and performs arithmetic processing of the CPU 5 based on instructions of these programs and temporarily stores various data such as processing results. The ROM 6 also stores an angle automatic adjustment program and a speed correspondence adjustment program used in the angle automatic adjustment mode and the speed correspondence adjustment mode.

  The display driver 10 is a processor that converts a video signal output from the DSP 11 into a video signal based on a predetermined standard and outputs the video signal to the display unit 20. A configuration in which the CPU 5 or the DSP 11 performs software processing may be employed.

  The storage unit 8 is composed of a nonvolatile memory such as a hard disk or a flash memory. Various application programs and various video data to be displayed on the display unit 20 are stored. In the present embodiment, the user's height: L, the angle of view of the camera module 26: φ, and the set time: t, which are used in the processing in the automatic angle adjustment mode and the speed correspondence adjustment mode, are stored. For example, these may be set in advance when the HMD 1 is shipped or distributed, or may be set by the user in each mode to be described later.

A DSP (Digital Signal Processor) 11 is an image processing processor that performs various kinds of image processing on the video signal output from the camera module 26 described later and outputs the video signal after the image processing to the display driver 10. A graphic memory (not shown) that temporarily stores an input video signal, a video signal subjected to image processing, and the like is provided, and the video signal is appropriately synchronized with the processing speed of various devices of the display unit 20 and the display driver 10. Output.
Note that the CPU 5 and the RAM 7 may be used to perform software image processing.

  The servo motor control circuit 12 is a control circuit that drives and controls a servo motor 27 that rotates the camera unit 21 of the HMD 1. Based on the instruction signal sent from the CPU, the gain of the electric power supplied to the servo motor 27 is adjusted and rotated to an intended angle.

  The angular position determination circuit 13 determines the current angle of the camera unit 21 based on a signal transmitted from the angular position sensor 22 and transmits the result to the CPU 5.

  The vibration speed determination circuit 14 detects the moving speed of the user wearing the HMD 1 by vibration and sends it to the CPU 5, and is used in a speed-corresponding adjustment mode described later.

  The sound source LSI 15 performs voice guidance when inputting various set values in the automatic angle adjustment mode or the speed-adaptive adjustment mode. For example, a sound source format such as an FM sound source or a PCN sound source is applied, a sine wave is generated based on input audio data, and a modulated wave is generated by performing frequency modulation between these signals to show various timbres. Generate an audio signal. The generated audio signal is output as audio via the earphone 24.

  The vibration motor drive circuit 16 receives a command signal from the CPU 5 and supplies drive power to the vibration motor 25 when the angle of the camera unit 21 is different from the set angle. When the angle is changed, the user is warned by vibration.

  The operation unit 9 is a setting switch (hereinafter referred to as “SW”) 18 for setting various display settings such as display brightness and contrast of the display unit 20, and a mode switch 19a for switching to the angle automatic adjustment mode. , A mode switch SW 19b for switching the mode to the speed corresponding adjustment mode, a cross key 60 for inputting setting values in various modes, and a determination key 61 for determining the setting by the cross key 60. The user inputs an instruction signal to the CPU 5 by operating these SWs and keys.

  Next, the display unit 3 will be described. The display unit 3 includes a display unit 20, a camera unit 21, an angular position sensor 22, a vibration sensor 23, an earphone 24, and a vibration motor 25. As shown in FIG. 2, the display unit 20 is provided from the center part to the upper end part of the lens part 41 provided in the eyeglasses 40.

  FIG. 3 is a cross-sectional view of the display unit 20 observed from the right side. The display unit 20 includes a video generation unit 30 and an eyepiece optical system 31. Inside the housing 38 that is the main body of the display unit 20, a transmissive liquid crystal display 35 that generates an image from an image signal transmitted from the control unit 2, and R, G, and B color LEDs ( An illumination optical system 34 is provided for guiding irradiation light from the Light Emitting Diode) group 33 and the LED group 33 to the entire surface of the liquid crystal display 35 by refraction.

The eyepiece optical system 31 further includes a prism 36 and a hologram optical element 37. The prism 36 has the same thickness as the lens portion 41, and the surface in the eyepiece direction is formed larger than the surface in the external field direction. The central portion from the upper end portion of the lens portion 41 is cut out along this shape, and by joining the prism 36 to the cut-out portion, the surfaces of the lens portion 41 and the prism 36 are integrated and smooth. It is configured. A sheet-like hologram optical element 37 is disposed at the lower end portion of the prism 36 and is provided so as to be sandwiched between the joint surface with the lens portion 41.
The upper end portion of the prism 36 has a thick wedge shape in the front direction, and is formed so that the image light beam emitted from the liquid crystal display 35 can be easily taken. The image light beam collected from the upper end is guided to the hologram optical element 37 provided at the lower end while being totally reflected inside the prism 36. The hologram optical element 37 makes light interfere with each other and forms a virtual image on the eyeball E.
The eyepiece optical system 31 is composed of a single member having the same refractive index of light as the lens unit 41.
The user can observe the external field of view through the lens unit 41 and the eyepiece optical system 31 and can observe an image superimposed on the external field of view through the hologram optical element 37.

  The camera unit 21 includes a camera module 26 and a servo motor 27. The camera module 26 is an imaging device including a photoelectric conversion element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) image sensor. Capture video in the user's line of sight. The video signal acquired by the camera module 26 is subjected to correlated double sampling of the analog video signal by a CDS (Correlated Double Sampling) circuit and an A / D (Analog / Digital) conversion circuit (not shown) to reduce and remove noise. At the same time, gain adjustment is performed, and after being converted into a digital video signal, it is output to the DSP 11.

  The camera unit 21 is provided at substantially the same height as the pupil of the glasses 40. Since the video captured by the camera module 26 is expanded as visual aid, for example, as shown in FIGS. 1 and 9, the video that is provided in the right frame of the glasses 40 and captures almost the same video as the video that enters the pupil can be captured. ing. As shown in FIG. 9, the camera unit 21 can adjust the depression angle in the optical axis direction. The angle φ in the optical axis direction is automatically set by calculation in the angle automatic adjustment mode and the speed corresponding adjustment mode. FIG. 4 shows the configuration of the camera unit 21. In the camera unit 21, a pedestal 45 is fixed to the right frame of the glasses 40, and a servo motor 27 is provided inside. The servo motor 27 has terminals 52 a and 52 b connected to a control line (not shown), and its rotation is controlled by supplying power from the servo motor control circuit 12. The rotating shaft 53 of the servo motor 27 is joined to the arm 48 through the washer 46a, the rotation control board 47, and the washer 46b. The arm 48 has a shape extending in the rotation direction of the rotary shaft 53, and a convex portion 49 having a cylindrical shape is provided at the tip of the arm 48 in a direction opposite to the direction facing the rotation control board 47. The surface of the camera module main body 51 that contacts the pedestal 45 is provided with a cylindrical concave portion 50 having a slightly larger inner circumference than the convex portion 49, and the convex portion 49 can be inserted into the concave portion 50.

  The camera module main body casing 51 is formed integrally with the camera module 26, and the camera module main body casing 51 can be rotated to an elevation angle in the optical axis direction along a guide groove 55 provided on the inner wall surface of the base 45. A suspension 56 is provided. The angle of the camera module 26 in the optical axis direction can be changed by suspending the suspension portion 56 in a guide groove 55 provided on the inner wall surface of the pedestal 45. Further, by rotating the servo motor 27, an arm can be obtained. The angle of the camera module 26 can be automatically changed by rotating the rotatable camera module main body casing 51.

  A fitting convex portion 58 is provided on the outer periphery of the rotation control board 47. The fitting convex portion 58 is adapted to be fitted with a fitting concave portion 57 provided on the inner wall surface of the pedestal 45. When the fitting convex portion 58 is fitted with the fitting concave portion 57, the rotation control panel is provided. 47 rotation is limited. The surface facing the arm 48 of the rotation control board 47 is in contact with the side surface of the arm 48 to restrict further rotational driving so that the imaging direction of the camera module 26 does not rotate upward from the horizontal. A stopper 54 is provided. By providing the stopper 54, the camera module 26 does not capture an image above the horizontal direction even when the camera unit 21 is inadvertently contacted. In the state where the stopper 54 and the arm 48 are in contact with each other, the imaging direction (lens optical axis) of the camera module 26 is oriented in the viewing direction (horizontal direction).

Next, the automatic angle adjustment mode will be described. In the automatic angle adjustment mode, when the user wears the HMD 1, the height of the camera unit 21 from the ground is set via the operation unit 9, so that the optical axis of the camera is set to a desired range. This function adjusts the angle of the direction. This angle adjustment is performed according to an instruction from the CPU 5 in accordance with an automatic angle adjustment program stored in the ROM 6 or the storage unit 8.
Here, referring to FIG. 5, the imaging field angle of the camera module 26: θ, the height of the camera unit 21 from the ground: L, the maximum value of the imaging range: Dmax, the minimum value of the imaging range: Dmin, and the optical axis The relationship of the angle of direction: φ will be described. In FIG. 5, only the camera unit 21 is shown, and the appearance of the HMD 1 is omitted. In the following description, the angle φ of the camera unit 21 in the optical axis direction is assumed to be 0 ° in the vertical direction and 90 ° in the horizontal direction.

The minimum values up to the imaging range shown in FIG. 5: Dmin, the height of the camera module 26: L, the angle of view: θ, and the camera angle: φ have the relationships shown in the following equations (3) and (4).

When Expression 2 is expanded using the addition theorem of trigonometric functions, the camera angle: φ can be obtained by the deformation shown in the following Expressions (5) to (9) and (1).

That is, from the above formulas (1) to (9), if the shortest distance: Dmin and the angle of view: θ of the imaging range are determined in advance, the camera angle: φ is uniformly according to the height of the camera from the ground: L. I understand that it will be fixed. As a specific example, if it is assumed that Dmin = 2 m, θ = 26 °, and L = 1.7 m, and is substituted into the above equation (1), the following equation (10) is obtained.

以下の〔表１〕に、撮像範囲の最小値：Ｄｍｉｎを２ｍと１ｍとした場合、撮像画角：θを２６°と４０°とした場合における、身長毎のカメラ角度：φ及びＤｍａｘの値を示す。

From equation (10), it can be seen that the camera angle should be 62.6 ° under this condition (90-62.6 = 27.4 ° when the horizontal direction is 0 °).
The maximum value Dmax with respect to the imaging range can be obtained by the following mathematical formula (11).

Table 1 below shows the values of the camera angles for each height: φ and Dmax when the minimum value of the imaging range: Dmin is 2 m and 1 m, and the imaging angle of view: θ is 26 ° and 40 °. Indicates.

  As is clear from the above, in the automatic angle adjustment mode, the angle of view of the camera module 26 is stored in advance, and the user inputs the minimum value of the imaging range and the height of the camera, whereby the optical axis of the camera unit 21 is obtained. The angle of the direction can be calculated uniformly.

Next, the operation of the HMD 1 in the automatic adjustment mode will be described using the flowchart shown in FIG. The following processing is performed by the CPU 5 in accordance with the automatic adjustment program.
When the user operates the automatic adjustment mode switching SW 19 of the operation unit 9, the CPU 5 displays a setting guidance screen for the automatic adjustment mode on the display unit 20 (step S101).

  In the setting guidance display, as shown in FIG. 7A, a display for requesting input of the user's height and the minimum value of the imaging range is performed. When the user operates the cross key 60 and the enter key 61 of the operation unit 9 to input the minimum values of the height and the imaging range (step S102), the CPU 5 determines each value based on the mathematical formula (1) described above. Is substituted, and a camera angle calculation process for calculating a target angle in the optical axis direction (hereinafter referred to as “target angle Y”) is performed (step S103).

  Next, the current angle of the camera unit 21 (hereinafter referred to as “current angle X”) is acquired from the angular position determination circuit (step S104). Next, a calculation for subtracting the target angle Y from the current angle X is performed (step S105).

  In step S106, it is determined whether the result obtained by the calculation in step S105 is equal to 0 °. If the result is equal (step S106: YES), the automatic angle adjustment mode is terminated.

  If it is not equal to 0 ° in step S106 (step S106: NO), it is determined whether the calculation result is positive (step S107). If it is positive (step S107: YES), the target angle Y is temporarily stored in the RAM 7 and an instruction signal is sent to the servo motor control circuit 12 to drive the servo motor 27 (step S108). The CPU 5 compares the angle value appropriately input from the angle position determination circuit 13 with the target angle Y temporarily stored in the RAM 7 in step S108 (step S109), and continues to drive the servo motor 27 until they match. (Step S109: NO). If the two coincide with each other in step S109, the automatic angle adjustment mode is terminated.

  If it is determined in step S107 that the calculation result in step S106 is not positive (step S107: NO), the CPU 5 temporarily stores the target angle Y in the RAM 7 and drives the servo motor 27, assuming that the calculation result is negative. Thus, the camera unit 21 is rotated in the direction opposite to that in step S108, and the angle adjustment of the camera unit 21 is performed (step S110). That is, the current supply direction to the servomotor 27 is reversed from that in step S108.

  Next, the CPU 5 compares the angle value of the camera unit 21 appropriately input from the angular position determination circuit 13 with the target angle Y temporarily stored in the RAM 7 in step S110 (step S111), and servos until both match. The motor 27 is continuously driven (step S111: NO).

  As described above, in the automatic angle adjustment mode, simply by inputting the user's height and the minimum value of the imaging range, the angle of the camera unit 21 that captures a suitable image desired by the user is automatically calculated. Therefore, even if the user of the HMD 1 or the usage environment is different, there is an effect that a suitable image is immediately displayed. In particular, the range captured as an image tends to be different between the image displayed on the HMD 1 and the actual field of view. For this reason, the video acquired via the display unit 20 of the HMD 1 may give a floating feeling to some users, and there is a problem to be solved as a visual assistance device. In this regard, the HMD 1 in the present embodiment exhibits a unique effect that it can immediately respond to changes in personal physical condition and preferences of the user.

Next, the “speed corresponding adjustment mode” will be described. The speed corresponding mode is a function of automatically adjusting the angle of the camera unit 21 based on the current speed in order to display a desired range of video when the user wearing the HMD 1 runs.
The above-described automatic angle adjustment mode is an angle adjustment function of the camera unit 21 when an image desired by a person with a disability in the eye is, for example, in the vicinity of 3 to 5 m ahead of the field of view. However, when running as a characteristic of human eyes, there is a feature that the line of sight is directed to a farther area than during walking. This is an instinct for trying to recognize obstacles earlier according to their own speed. In this respect, in the automatic angle adjustment mode, it is naturally possible to set a desired imaging range farther (the minimum value of the above-described imaging range: the value of Dmin is set farther).
However, in daily life, it takes more time to walk than when running, and it is bothersome and impractical for the user to change the settings sequentially each time they run or walk.
Therefore, in the speed corresponding adjustment mode, the speed of the user is detected, and the angle of the camera unit 21 is automatically adjusted so as to capture an image of a more forward area in accordance with the speed.

A vibration sensor 23 and a vibration speed determination circuit 14 are used to detect the moving speed of the user. The output vibration frequency: f from the vibration sensor 23 provided in the display unit 3 is input, and the vibration speed determination circuit 14 calculates the current speed V of the user. When this speed: V is multiplied by an arbitrary set time: t (sec), the distance to the area (place) where the central optical axis of the camera unit 21 is captured is D. From the above, the camera angle: φ of the camera unit 21 is related to the speed: V, the set time: t, and the height of the camera unit 21 from the ground: L by the following formula (2). The camera angle of the camera unit 21: φ can be obtained.

  Next, processing in the speed corresponding adjustment mode will be described with reference to the flowchart of FIG. Note that the following processing is performed by the CPU 5 in accordance with the speed correspondence adjustment program stored in the ROM 6.

  When the user operates the mode switching SW 19b of the operation unit 9, the speed corresponding adjustment mode is activated, and the CPU 5 displays a setting guidance screen as shown in FIG. Step S201).

  According to the guidance on the setting guidance screen displayed in step S201, the user's height (height of the camera unit 21: L) input from the user via the cross key 60 and the enter key 61 and the arrival time to the desired imaging region : T is stored in the storage unit 8 (step S202).

  Next, the current speed sent from the vibration speed determination circuit 14 is acquired (step S203). From this speed: V, the user's height (height of the camera unit 21: L) and the arrival time: t stored in the storage unit 8, the angle of the camera unit 21: φ based on the above-described equation (2) (Hereafter, calculation processing for calculating “speed-corresponding angle Z” is performed (step S204).

  Next, the current angle X of the camera unit 21 is acquired from the angular position determination circuit 13 (step S205). A calculation is performed to subtract the speed corresponding angle Z acquired in step S204 from the current angle X acquired in step S205 (step S206).

  In step S207, it is determined whether the result obtained by the calculation in step S206 is equal to 0 °. If the result is equal (step S207: YES), the speed corresponding adjustment mode is terminated.

  If it is not equal to 0 ° in step S207 (step S207: NO), it is determined whether the calculation result is positive (step S208). If it is positive (step S208: YES), the speed corresponding angle Z is temporarily stored in the RAM 7, and an instruction signal is sent to the servo motor control circuit 12 to drive the servo motor 27 (step S209). The CPU 5 compares the angle value sent from the angular position determination circuit 13 with the speed corresponding angle Z temporarily stored in the RAM 7 in step S209 (step S210), and continues to drive the servo motor 27 until they match. (Step S210: NO). If the two match at step S210, the speed corresponding adjustment mode is terminated (step S210: YES).

  If it is determined in step S208 that the calculation result in step S206 is not positive (step S208: NO), the CPU 5 temporarily stores the speed corresponding angle Z in the RAM 7 and assumes that the servo motor 27 is stored, assuming that the calculation result is negative. A process of rotating the camera unit 21 to adjust the imaging angle is performed (step S211). Note that the driving direction of the servo motor 27 at this time is opposite to that in step S209 described above. That is, the current supply direction to the servo motor 27 is reversed from that in step S209.

  Next, the CPU 5 compares the angle value of the camera unit 21 appropriately input from the angular position determination circuit 13 with the speed corresponding angle Z temporarily stored in the RAM 7 in step S211 (step S212), and until the two match. The servo motor 27 is continuously driven (step S212: NO). If both angles match in step S212, the speed corresponding adjustment mode is terminated (step S212).

  As described above, according to the speed corresponding adjustment mode of the HMD 1 to which the present invention is applied, the imaging range captured by the camera module 26 can be further advanced in accordance with the moving speed of the user. In general, the human field of view tends to desire a more forward field of view than when walking when running for early risk prediction. According to the speed-adaptive adjustment mode of the HMD 1, the angle in the optical axis direction of the camera unit 21 is automatically adjusted by simply setting the arrival time to the area where the user wants to take an image, The video can be displayed.

  Further, since the rotation control panel 47 provided in the camera unit 21 of the HMD 1 is provided with a stopper 54 that restricts the angle in the optical axis direction to a horizontal plane or less, even if the camera unit 21 is accidentally contacted, the optical axis direction is at least horizontal. The video in the depression direction necessary for walking or the like is not lost completely. For this reason, the convenience and safety | security as a visual assistance apparatus further improve.

  The best mode for carrying out the present invention has been described above, but the present invention is not limited to the various examples described above.

It is the block diagram which showed the structure of HMD in the best form for implementing this invention. It is the schematic which showed the external appearance structure of HMD in the best form for implementing this invention. It is the sectional side view which showed the structure of the display part of HMD in the best form for implementing this invention. It is the figure which showed the structure of the camera unit of HMD in the best form for implementing this invention. It is the schematic diagram which showed the relationship between the minimum value and the maximum value of the height of a camera unit in the best form for implementing this invention, an angle of view, and an angle, and an imaging range. It is the flowchart which showed the process of the "angle automatic adjustment mode" in the best form for implementing this invention. FIG. 7A is a schematic diagram showing an example of the guidance screen of the “automatic angle adjustment mode” in the best mode for carrying out the present invention. FIG. 7B is a schematic diagram showing an example of a guidance screen of “speed corresponding adjustment mode” in the best mode for carrying out the present invention. It is the flowchart which showed the process of the "speed corresponding | compatible adjustment mode" in the best form for implementing this invention. It is the schematic which showed the structure of the camera unit in the best form for implementing this invention. It is the schematic diagram which showed the imaging range imaged with a small camera at the time of mounting | wearing with HMD.

Explanation of symbols

1 HMD
2 Control unit 3 Display unit 4 Control unit 5 CPU
6 ROM
7 RAM
8 Storage unit 9 Operation unit 10 Display driver 11 DSP
12 Servo Motor Control Circuit 13 Angular Position Determination Circuit 14 Vibration Speed Determination Circuit 15 Sound Source LSI
16 Vibration motor drive circuit 17 Cable 18 Display setting SW
19a, 19b Mode switch SW
DESCRIPTION OF SYMBOLS 20 Display part 21 Camera unit 22 Angular position sensor 23 Vibration sensor 24 Earphone 25 Vibration motor 26 Camera module 27 Servo motor 28 Battery 30 Image generation unit 31 Eyepiece optical system 33 LED group 34 Illumination optical system 35 Liquid crystal display 36 Prism 37 Hologram optics Element 38 Case 40 Glasses 41 Lens part 45 Base 46a, 46b Washer 47 Rotation control panel 48 Arm 49 Protruding part 50 Concave part 51 Camera module main body case 52a, 52b Terminal 53 Rotating shaft 54 Stopper 55 Guide groove 56 Suspension part 57 Fitting Concave part 58 Fitting convex part 60 Cross key 61 Enter key

Claims (8)

An imaging unit that captures an image in the line of sight of the observer, a projection unit that converts the image signal obtained by the imaging unit into an optical image, and projects the optical image from the projection unit on the pupil of the observer In a display device comprising eyepiece optical means for guiding,
Support means for supporting the imaging means at substantially the same position as the pupil of the observer;
A display device comprising: an adjusting unit that adjusts an optical axis direction of the imaging unit to a direction that forms a depression angle with respect to a horizontal plane passing through the observer. The display device according to claim 1,
The adjusting means is
A drive means provided at a connecting portion between the support means and the imaging means, and for causing the imaging means to move up and down with respect to a horizontal plane passing through the observer;
An angle detecting means for detecting an elevation angle formed between the imaging means and the horizontal plane in the optical axis direction;
Storage means for storing a predetermined reference elevation angle;
A comparison means for comparing the elevation angle detected by the angle detection means with the reference elevation angle and detecting the difference angle;
A display device comprising: a control unit that outputs to the drive unit an instruction signal for correcting an optical axis direction of the imaging unit based on the difference angle obtained by the comparison unit. The display device according to claim 2,
The display device further comprising a warning unit that warns that the reference elevation angle and the angle in the optical axis direction of the imaging unit do not match when the difference angle is detected by the comparison unit. The display device according to claim 2 or 3,
The angle of view of the image pickup means is θ, the height of the image pickup means from the ground is L, and the minimum distance from the point of intersection with the ground to the image pickup range captured by the image pickup means when the perpendicular is dropped from the image pickup means is Dmin. When the vertical direction of the image pickup means is 0 ° and the horizontal plane is 90 °, the angle φ in the optical axis direction of the image pickup means is specified by the following formula (1) and stored in the storage means as the reference elevation angle A display device further comprising angle calculation means for storing.

The display device according to any one of claims 2 to 4,
A moving speed detecting means for detecting the moving speed of the observer;
And a time angle setting means for storing the elevation angle in the optical axis direction of the imaging means as the reference elevation angle in the storage means based on the arrival time to the imaging range imaged by the imaging means. Display device. The display device according to claim 5,
When the height of the imaging means from the ground is L, the moving speed detected by the moving speed detecting means is v, the arrival time is t, the vertical direction of the imaging means is 0 °, and the horizontal plane is 90 ° The time angle setting means specifies the angle φ of the image pickup means in the optical axis direction by the following mathematical formula (2), and stores it in the storage means as the reference elevation angle.

The display device according to any one of claims 1 to 6,
The display apparatus according to claim 1, wherein the eyepiece optical means transmits external light and superimposes the video on the external visual field. The display device according to any one of claims 1 to 7,
The eyepiece optical means includes a prism for guiding an optical image projected from the projection means;
A display device comprising: a hologram element that connects a virtual image of an optical image guided by the prism to a pupil.

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