JP2017116755A - Virtual image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust an angle of a reflection mirror according to fluctuation of driver's posture, in a virtual image display device.SOLUTION: A virtual image display device which can adjust an angle of a reflection mirror includes a light source part for virtual image display, a light source part for detecting a position of a driver's eye, a reflection mirror, a reflection mirror drive unit, a wind shield, a synchronous unit, a control part, a virtual image, and a content control part. The synchronous unit includes a reflection type element in which a convex surface and a concave surface are arrayed alternately, a convex lens, and a sensor, and moves in synchronous with the driver's eye. Further, based on a signal that is generated when the light from the light source part traverses the reflection type element, the control part controls the reflection mirror drive unit by feedback control.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a virtual image display device such as an automotive head-up display.

  A head-up display (hereinafter referred to as “HUD”) is a device that displays driving assistance information such as speed or navigation information as a virtual image on a windshield of an automobile. The driver can visually recognize the foreground of the vehicle and the driving support information in a superimposed manner. For this reason, the movement of the line of sight during driving is reduced, and the driver's fatigue can be reduced or the safety can be improved.

  In order for the driver to visually recognize the virtual image, it is necessary to match the eye range of the head-up display with the position of the driver's eyes.

  The “eye range” is a statistical representation of the driver's eye position distribution. Here, the eye range is a range of eye positions where a virtual image can be recognized. The eye range is also called an eye box. The eye box shows a rectangular area corresponding to the “view window”. The driver can see the virtual image only while looking at the road from this window.

  In order to make the driver visually recognize the virtual image, the light from the light source unit is reflected toward the windshield using a reflection mirror. Then, the virtual image is displayed in front of the windshield by reflecting light from the windshield toward the driver's eyes.

  Note that the position of the driver's eyes moves up, down, left, and right due to changes in the driver's posture. In such a case, the driver's eyes may be out of the eye range. This is determined by the size of the eye range and the amount of change in the posture of the driver. Then, the driver cannot recognize the virtual image.

  Therefore, by changing the angle of the reflection mirror, the arrival position of the light from the windshield toward the driver's eyes is changed. As a result, the driver can always recognize a virtual image even when the posture changes.

  In order to drive the reflection mirror, it is necessary to detect the position of the driver's eyes. A technique for detecting the position of the driver's eyes or the position of the driver's head is described in Patent Document 1, for example.

  Japanese Patent Application Laid-Open No. 2004-133620 discloses a technique for imaging a driver with a 3D camera, detecting the position of the driver's eyes by image processing, and adjusting the display position of an image according to the detection result.

JP 2010-128000 (paragraphs 0025 to 0026, 0029 to 0030, FIG. 1)

  However, in the technique disclosed in Patent Document 1, a plurality of processes occur from when the driver's posture is changed to when the arrival position of the light toward the driver's eyes is changed. For this reason, it takes time to change the arrival position of the light toward the driver's eyes. The plurality of processes are, for example, processes such as photographing a driver with a 3D camera and performing image processing on the photographed images.

  Therefore, the present invention has been made to solve these problems, and provides a virtual image display device that can easily simplify the process from when the driver's posture fluctuates until the reflecting mirror is driven. With the goal.

  A virtual image display device according to the present invention includes a light source that emits detection light for detecting a position of an eye of a person who visually recognizes a virtual image, a synchronization unit that moves in synchronization with the eye, and an image including information on the virtual image A reflection mirror that adjusts the optical path of the light and the detection light; and a reflection mirror drive unit that adjusts the reflection angle of the reflection mirror; and the synchronization unit includes a reflection element and a convex lens in which convex and concave surfaces are alternately arranged. And the sensor, the reflective element reflects the detection light incident via the convex lens, and the sensor receives the detection light reflected by the reflective element and drives the reflective mirror. The unit generates a sensor signal for controlling the reflection mirror.

  ADVANTAGE OF THE INVENTION According to this invention, the drive process of the reflective mirror for changing the arrival position of the light which faces a driver | operator's eyes can be simplified.

1 is a configuration diagram schematically showing a configuration of a virtual image display device according to Embodiment 1. FIG. 3 is a configuration diagram showing a configuration of a synchronization unit that is a part of the virtual image display device according to Embodiment 1. FIG. 6 is a diagram schematically illustrating an example of a signal generation method in a sensor of the virtual image display device according to Embodiment 1. FIG. It is a figure which shows roughly the signal produced | generated when the light radiate | emitted from the light source part for a driver | operator's eye position detection crosses the reflective element of the virtual image display apparatus which concerns on Embodiment 1. FIG. FIG. 10 is a diagram schematically showing a configuration of a virtual image display device according to a modification of the first embodiment. It is a figure which shows schematically the structure of the content control part of the virtual image display apparatus which concerns on the modification of Embodiment 1, and a reflective mirror drive unit. FIG. 10 is an explanatory diagram showing an operation of a reflection mirror drive unit 300 according to a modification of the first embodiment. It is a figure which shows roughly the relationship between the moving amount | distance of the video content of the virtual image display apparatus which concerns on the modification of Embodiment 1, and the moving amount | distance of a reflective mirror drive unit. It is a block diagram which shows schematically the structure of a general virtual image display apparatus.

  FIG. 9 is a configuration diagram schematically showing a configuration of a general virtual image display device 10.

  In the drawings shown below, xyz coordinates are used for ease of explanation. The traveling direction of the vehicle is the x-axis direction. The front of the vehicle is the + x-axis direction, and the rear is the -x-axis direction. The left-right direction of the vehicle is the y-axis direction. The right side of the vehicle is the + y axis direction, and the left side of the vehicle is the −y axis direction. The vertical direction of the vehicle is the z axis. The upward direction of the vehicle is the + z-axis direction, and the downward direction is the −z-axis direction.

  As shown in FIG. 9, a general virtual image display device 10 includes a light source unit 100, a reflection mirror 110, and a reflection mirror drive unit 120. The virtual image display device 10 can include a content control unit 160.

  The driver can view the virtual image 150 through the windshield 130.

  The light source unit 100 generates light 101 (hereinafter referred to as image light) including image information of driving support information. The light source unit 100 includes an image display element. The image display element is, for example, a Liquid Crystal On Silicon (LCOS), a Liquid Crystal Display (LCD), or a laser.

  The reflection mirror 110 reflects the image light 101 generated by the light source unit 100. Then, the reflection mirror 110 causes the image light 101 to enter the windshield 130. As a result, the virtual image display device 10 enlarges and displays the virtual image in the + x-axis direction (front of the vehicle) of the windshield 130 as viewed from the driver.

  The reflection mirror drive unit 120 adjusts the angle of the reflection mirror 110. The virtual image display device 10 can change the optical path of the image light 101 from the light source unit 100 by the reflection mirror driving unit 120 adjusting the angle of the reflection mirror 110. The reflection mirror drive unit 120 includes, for example, a motor, a motor driver, a motor controller, and the like.

  The windshield 130 is a vehicle windshield. The image light 101 reflected by the reflection mirror 110 enters the windshield 130. The image light 101 reflected by the windshield 130 reaches the driver's eyes 140. The driver can view the image included in the image light 101 as a virtual image 150 displayed in an enlarged manner in the + x-axis direction. That is, the windshield 130 is a transmissive display unit that reflects the image light 101 from the virtual image display device 10 and allows the driver to visually recognize the scenery in front of the vehicle.

  A combiner can be used instead of the windshield 130. A “combiner” is a translucent screen placed on the windshield side. The driving information is reflected on this combiner to enter the driver's field of view.

  The driver can view the virtual image 150 simultaneously with looking at the foreground of the vehicle. That is, the driver is a person who visually recognizes the virtual image.

  The virtual image 150 is an image displayed in the + x-axis direction of the windshield 130 with the image information generated by the light source unit 100 enlarged.

  The content control unit 160 controls an image displayed as the virtual image 150. Specifically, the content control unit 160 sets the content of the image to be displayed.

  For example, it is assumed that the driver's eyes 140 are moved in the z-axis direction due to a change in the driver's posture. Depending on the amount of change in the posture of the driver, the position of the driver's eye 140 is out of the eye range. And a driver cannot visually recognize a virtual image.

  Therefore, the reflection mirror drive unit 120 adjusts the angle of the reflection mirror 110. The reflection mirror drive unit 120 adjusts the angle of the reflection mirror 110 so that the image light 101 is applied to the position of the driver's eyes 140.

  In FIG. 9, when the angle of the reflection mirror 110 changes, the optical path of the light 101 emitted from the light source unit 100 changes from a solid line to a one-dot chain line. In FIG. 9, the optical path toward the driver's eyes 140 is translated in the −z-axis direction. The eye range moves in the −z axis direction. Thereby, the driver can recognize the virtual image.

Embodiment 1 FIG.

  FIG. 1 is a configuration diagram schematically showing the configuration of the virtual image display device 11 according to the first embodiment. FIG. 2 is a configuration diagram showing the configuration of the synchronization unit 250. FIG. 2A shows the synchronization unit 250 when the driver's eyes 260 are in the reference position. FIG. 2B shows the synchronization unit 250 when the driver's eyes 260 move upward (+ z-axis direction side) from the reference position.

  As shown in FIG. 1, the virtual image display device 11 according to the first embodiment includes a light source unit 20, a reflection mirror 220, a reflection mirror drive unit 230, and a synchronization unit 250. The virtual image display device 11 can include a control unit 270 and a content control unit 290.

  In FIG. 1, the light source unit 20 includes, for example, a light source unit 200 and a light source unit 210. The light source unit 200 emits image light to form a virtual image. The light source unit 210 emits detection light for detecting the position of the driver's eyes 260. For example, the light source unit 200 and the light source unit 210 can include different light sources. Further, for example, light from one light source can be divided, image light can be generated by the light source unit 200, and detection light can be generated by the light source unit 210. That is, the light source unit 200 and the light source unit 210 may be integrated.

  Thereby, the installation space of the light source unit 20 can be made small, and manufacturing cost can also be reduced. In this case, the light source unit 20 in which the light source unit 200 and the light source unit 210 are integrated emits the image light 201 and the detection light 211 together.

  The driver can view the virtual image 280 through the windshield 240. It can be said that the windshield 240 is a display surface of the virtual image 280.

  In FIG. 1, a light source unit 200 is the same as the light source unit 100 of FIG. The reflection mirror 220 is the same as the reflection mirror 110 in FIG. The reflection mirror drive unit 230 is the same as the reflection mirror drive unit 120 of FIG. The windshield 240 is the same as the windshield 130 of FIG. The content control unit 290 is the same as the content control unit 160 of FIG. The description of these components 200, 220, 240, and 290 is substituted with the description of the components 100, 110, 120, 130, and 160 in FIG.

  The light source unit 200 generates image light 201 including image information of driving support information. The image light 201 is the same as the image light 101.

  The light source unit 210 generates detection light 211 for detecting the position of the driver's eyes 260. For example, a laser is used as the light source unit 210. In the first embodiment, two types of light beams emitted from the light source unit 20 travel on the same optical path. The two types of light beams are the light beam of the image light 201 and the light beam of the detection light 211. In the first embodiment, the image light 201 is also irradiated to the position of the driver's eyes 260 to which the detection light 211 is irradiated.

  In other words, the image light 201 is also irradiated to the position of the driver's eye 260 by adjusting the angle of the reflection mirror 220 so that the detection light 211 is irradiated to the position of the driver's eye 260. The driver can recognize the virtual image.

  The synchronization unit 250 is a unit that moves in synchronization with the driver's eyes 260.

  For example, the synchronization unit 250 may be worn by a driver. For example, the synchronization unit 250 is attached to the driver like glasses. In this case, the synchronization unit 250 and the driver's eyes 260 move the same distance.

  The synchronization unit 250 may be installed in front of the driver's eyes 260. In this case, the synchronization unit 250 and the driver's eyes 260 do not necessarily have to move the same distance.

The synchronization unit 250 moves in a linear relationship with the driver's eye 260. Here, “linear” is a relationship represented by the following Equation 1. Where v is the position of the synchronization unit 250, u is the position of the driver's eye 260, t is time, m and n are natural numbers, and {a _i } (i = 0, 1, .., N), {b _j } (i = 0, 1,..., M) are real constants.

  The synchronization unit 250 includes a reflective element 251, a convex lens 252, and a sensor 253.

  The reflective element 251 includes a surface in which convex surfaces and concave surfaces are alternately arranged.

  The uneven surface of the reflective element is, for example, a diffraction grating. A diffraction grating has a large number of parallel grooves cut at equal intervals on a flat surface or concave surface. In FIG. 1, for example, the grooves of the diffraction grating are aligned in the z-axis direction.

  The virtual image display device 11 of FIG. 1 shows a case where the driver's eye 260 moves on the z axis. However, the movement of the driver's eyes 260 is not limited to the z-axis direction. The virtual image display device 11 can also be applied when the driver's eyes 260 move in the y-axis direction. In this case, one set of reflective elements 251 in the synchronization unit 250 is added. That is, the synchronization unit 250 includes the reflective element 251 corresponding to the z-axis direction and the reflective element 251 corresponding to the y-axis direction. The grooves of the diffraction grating of the reflective element 251 corresponding to the y-axis direction are aligned in the y-axis direction.

  The grooves of the reflective element 251 are arranged in the moving direction of the synchronization unit 250. That is, the detection light 211 moves so as to cross the uneven surface. As described above, when the synchronization unit 250 moves in the z-axis direction, the grooves of the reflective element 251 are aligned in the z-axis direction. When the synchronization unit 250 moves in the y-axis direction, the grooves of the reflective element 251 are aligned in the y-axis direction.

There is no particular limitation on the interval between the grooves. However, if the interval between the grooves is equal, the direction in which the detection light 211 moves cannot be determined. Therefore, for example, the groove interval is formed so as to monotonously increase in the direction in which the detection light 211 moves. Or it forms so that the space | interval of a groove | channel may decrease monotonously. Thereby, as will be shown later as an example, the output signal S ₁ of the sensor 253 becomes a signal including information on the direction in which the detection light 211 moves.

  The convex lens 252 collects the detection light 211. The convex lens 252 collects the detection light 211 and forms a spot on the uneven surface of the reflective element 251. When the synchronization unit 250 moves in the z-axis direction, the incident angle of the detection light 211 on the convex lens 252 differs depending on the position of the synchronization unit 250 on the z-axis. Thereby, the incident angle to the reflective element 251 of the detection light 211 condensed by the convex lens 252 is different.

  When the incident angle of the detection light 211 is far from the optimum incident angle, the intensity of the detection light 211 incident on the sensor 253 decreases. Therefore, for example, the convex lens 252 can be tilted so that the intensity of the detection light 211 incident on the sensor 253 is constant. This requires a device for tilting the convex lens 252 (not shown).

For example, the sensor 253 receives first-order diffracted light reflected by the uneven surface of the reflective element. The sensor 253 generates a signal S ₁ based on the detection light 211 that crosses the groove of the reflective element 251. When the driver's eyes 260 move upward (+ z-axis direction side), the position of the detection light 211 incident on the reflective element 251 moves downward (−z-axis direction side). When the driver's eyes 260 continuously move upward (+ z-axis direction side), the detection light 211 incident on the reflective element 251 crosses the groove of the reflective element 251 in one direction. The synchronization unit 250 sends the signal S ₁ obtained by the sensor 253 to the control unit 270 at this time.

This signal S ₁ is used by the mirror drive unit 230 for feedback control of the reflection mirror 220.

Method of generating signals S ₁ of the sensor 253, for example, a push-pull method. The push-pull method will be described later with reference to FIG. This is one of the tracking control methods for Blu-ray discs. In tracking control, the first-order diffracted light from the groove carved in the track portion is received by a two-divided detector, and the difference is taken and controlled so that the difference becomes zero. This control is adjusted so that the center comes.

Figure 3 is a diagram schematically showing an example of a method of the sensor 253 generates a signal S _1. The interval tp is a length in which the concave and convex portions of the groove are set as one set. FIG. 3A shows a case where the incident position of the detection light 211 has moved upward (+ z-axis direction side) from the reference position by an interval tp / 4. FIG. 3B shows a case where the incident position of the detection light 211 is the reference position. FIG. 3C shows a case where the incident position of the detection light 211 moves downward (−z-axis direction side) from the reference position by an interval tp / 4.

The sensor 253 is divided into, for example, two divided windows 253a and 253b. That is, the sensor 253 is divided into two. The sensor 253 subtracts the intensity of the reflected light 212 from each of the divided windows 253a and 253b. The value of the difference in intensity of the reflected light 212, for example, a sensor signal S _1.

  When the synchronization unit 250 moves in the z-axis direction, the sensor 253 is divided into two in the vertical direction (z-axis direction). That is, the divided windows 253a and 253b are arranged side by side in the z-axis direction. When the synchronization unit 250 moves in the y-axis direction, the sensor 253 is divided into two in the left-right direction (y-axis direction). That is, the divided windows 253a and 253b are arranged side by side in the y-axis direction.

  In FIG. 3, the grooves of the reflective element 251 are aligned in the z-axis direction.

  In the case of FIG. 3A, the reflected light 212a on the convex surface of the reflective element 251 enters the divided window 253a on the upper side (+ z-axis direction side) of the sensor 253. Reflected light 212b on the concave surface of the reflective element 251 is incident on the divided window 253b on the lower side (−z-axis direction side) of the sensor 253.

  In the case of FIG. 3B, reflected light 212c on the concave surface of the reflective element 251 is incident on the split window 253a on the upper side (+ z-axis direction side) of the sensor 253. The reflected light 212d from the same concave surface of the reflective element 251 enters the divided window 253b on the lower side (−z-axis direction side) of the sensor 253.

  In the case of FIG. 3C, the reflected light 212e on the concave surface of the reflective element 251 is incident on the divided window 253a on the upper side (+ z-axis direction side) of the sensor 253. Reflected light 212f on the convex surface of the reflective element 251 is incident on the divided window 253b on the lower side (−z-axis direction side) of the sensor 253.

To detect the change in the position of the synchronization unit 250, the difference between the reflectance of the convex surface and the reflectance of the concave surface of the reflective element 251 is used. That is, the difference in intensity of the reflected light 212 between the two divided windows 253a and 253b is used. Sensor signals _{S 1,} the two split windows 253a, determined from the difference of the intensity of the reflected light 212 at 253b.

In the case of FIG. 3A, the signal Sa and the signal Sb are subtracted to obtain the sensor signal _S1a . The signal Sa is a signal obtained by converting the intensity of the reflected light 212a incident on the upper divided window 253a of the sensor 253 into an electric signal. The signal Sb is a signal obtained by converting the intensity of the reflected light 212b incident on the lower split window 253b on the sensor 253 into an electric signal.

In the case of FIG. 3B, the signal Sc and the signal Sd are subtracted to obtain the sensor signal _S1b . The signal Sc is a signal obtained by converting the intensity of the reflected light 212c incident on the upper divided window 253a of the sensor 253 into an electric signal. The signal Sd is a signal obtained by converting the intensity of the reflected light 212d incident on the lower divided window 253b of the sensor 253 into an electric signal.

In the case of FIG. 3C, the signal Se and the signal Sf are subtracted to obtain the sensor signal _S1c . The signal Se is a signal obtained by converting the intensity of the reflected light 212e incident on the upper divided window 253a of the sensor 253 into an electric signal. The signal Sf is a signal obtained by converting the intensity of the reflected light 212f incident on the lower divided window 253b of the sensor 253 into an electric signal.

For example, the sensor signals S _1a , S _1b , S _1c are obtained by subtracting the signals Sa, Sc, Se and the signals Sb, Sd, Sf by the subtractor 254. The signals Sa, Sc, and Se are signals obtained by converting the reflected lights 212a, 212c, and 212e that have entered the split window 253a on the upper side of the sensor 253 into electrical signals. The signals Sb, Sd, and Sf are signals obtained by converting the reflected lights 212b, 212d, and 212f incident on the lower division window 253b on the lower side of the sensor 253 into electric signals.

In FIG. 3A, the intensity of the reflected light 212a is greater than the intensity of the reflected light 212b. When the signal _{S 1a} the signal Sa- signal Sb, the signal _{S 1a} has a positive value.

In FIG. 3B, the intensity of the reflected light 212c is equal to the intensity of the reflected light 212d. When the signal _{S 1b} and signal Sc- signal Sd, signal _{S 1b} has a value of zero.

In FIG. 3C, the intensity of the reflected light 212e is equal to the intensity of the reflected light 212f. When the signal _S1c is a signal Se-signal Sf, the signal _S1c has a negative value.

Figure 4 is a diagram schematically showing a change of signals S ₁ when the synchronization unit 250 is moved. The signal S ₁ is a signal generated when the detection light 211 moves so as to cross the groove on the reflective element 251. The horizontal axis indicates the position where the detection light 211 enters the reflective element 251. The vertical axis represents the value of the signal S _1.

The values of the signals S _1a , S _1b , S _1c are values obtained by subtracting the values of the signals Sb, Sd, Sf from the values of the signals Sa, Sc, Se. That is, the values of the signals S _1a , S _1b , S _1c are values obtained by subtracting the intensity of the reflected light 212b, 212d, 212f incident on the divided window 253b from the intensity of the reflected light 212a, 212c, 212e incident on the divided window 253a. It is.

The sensor signal S _1a in FIG. 3A is a point where the signal S ₁ in FIG. 4 becomes maximum. The sensor signal S _1b in FIG. 3B is a point where the signal S ₁ in FIG. 4 becomes zero. In FIG. 3C, the sensor signal S _1c is a point at which the signal S ₁ in FIG. 4 is minimum.

  In FIG. 3B, the position where the detection light 211 is incident on the reflective element 251 is the concave surface of the reflective element 251 as the reference position. However, the case where the convex surface of the reflective element 251 is used as the reference position is shown below.

When the position of the detection light 211 incident on the reflective element 251 moves upward (+ z-axis direction side) by the interval tp / 4, unlike FIG. 3A, the sign of the sensor signal _S1a is negative. Become. Similarly, when the position of the detection light 211 incident on the reflective element 251 moves downward (−z-axis direction side) by the interval tp / 4, unlike FIG. 3C, the sensor signal S _1c The sign of is positive.

Thus, either a convex surface as a reference position, by either the concave as a reference position, the sign of the signals S ₁ in the case where the position is incident on the reflective element 251 of the detection light 211 is moved different. When the concave surface is used as the reference position, when the incident position of the detection light 211 moves upward, the sign of the signal S _1a becomes negative, and when the incident position of the detection light 211 moves downward, the sign of the signal S _1a becomes Become positive. On the other hand, in the case of a convex surface as a reference position, the incident position of detection light 211 is moved upward, the sign of the signal S _1a is positive, the incident position of detection light 211 is moved to the lower side, of the signal S _1a The sign is negative.

When the convex and concave surfaces of equally spaced, the waveform of the signals S ₁ in FIG. 4, a point symmetrical to the point showing a signal S _1b. For this reason, the direction in which the detection light 211 moves on the reflective element 251 cannot be grasped. That is, the moving direction when the detection light 211 moves across the groove on the reflective element 251 is unknown. In FIG. 3, it cannot be detected whether the detection light 211 is moving in the + z-axis direction or whether the detection light 211 is moving in the −z-axis direction.

In contrast, for example, the interval tp, with respect to the transverse direction of the detection light 211 (z-axis direction), in the case of decreasing monotonically increasing or monotonically, the waveform of the signals S ₁ in FIG. 4, the signal S _1b It is not point-symmetric with respect to the point indicating. That is, the half cycle of the waveform on the positive side of the horizontal axis and the waveform on the negative side of the horizontal axis are different from the point indicating the signal _S1b . For this reason, the direction in which the detection light 211 moves across the groove on the reflective element 251 can be grasped.

The control unit 270 sends a control signal S ₂ to the reflection mirror drive unit 230 based on the signal S ₁ output from the sensor 253 in the synchronization unit 250.

  Specifically, the control unit 270 performs feedback control. The control unit 270 includes a control filter and a drive amplifier for performing feedback control. The target value of the feedback control is the position of the driver's eyes 260.

The signal S ₁ is a signal converted into an electric signal by the sensor 253 in the synchronization unit 250. A signal S ₁ from the sensor 253 is input to the control filter 271.

  The control filter 271 is, for example, PID (Proportional Integral Derivative) control. PID control is a type of feedback control, and is a method of performing control of an input value by three elements: a deviation between an output value and a target value, an integration of the deviation, and a differentiation of the deviation.

Driving amplifier 272 amplifies the signal _{S 3} to the control filter 271 is output. Signal S ₃ is output voltage or output current control filter 271 is output. Drive amplifier 272 outputs a signal _{S 2} amplifies the signal _{S 3.} Signal S ₂ is amplified output voltage or output current. The drive amplifier 272 amplifies the signal S ₃ to a voltage or current necessary to control the reflection mirror drive unit 230.

As described above, in the virtual image display device 11 according to the first embodiment, the synchronization unit that moves the detection light 211 for detecting the position of the driver's eyes 260 in synchronization with the driver's eyes 260. The light is incident on the reflective element 251 in 250. The reflected light 212 reflected by the uneven surface (diffraction surface) of the reflective element 251 enters the sensor 253. Based on the amount of the reflected light 212, sensor 253 generates a sensor signal _{S 1.} Control unit 270, based on sensor signals _{S 1,} and sends a signal _{S 2} to the reflecting mirror driving unit 230. Reflecting mirror driving unit 230, based on the signal _{S 2,} and drives the reflecting mirror 220. For this reason, the virtual image display device 11 can reduce the time delay until the reflecting mirror 220 is driven.

<Modification>
In addition to the function of the virtual image display device 11, the virtual image display device 12 according to the modified example has a function of determining whether or not the driver has viewed the video.

  FIG. 5 is a configuration diagram schematically showing the configuration of the virtual image display device 12 according to the modification.

As shown in FIG. 5, in the virtual image display device 12, the signal S ₄ is sent from the content control unit 310 to the reflection mirror drive unit 300. The virtual image display device 12 is different from the virtual image display device 11 in this point.

  The light source unit 20, the reflection mirror 220, the synchronization unit 250, and the control unit 270 in FIG. 5 are the same as those in the virtual image display device 11 shown in FIG. The light source unit 20 includes a light source unit 200 and a light source unit 210. Moreover, the windshield 240 in FIG. 5 is the same as the windshield 240 shown in FIG.

  Hereinafter, differences from the virtual image display device 11 will be described.

The content control unit 310 controls an image displayed as the virtual image 280. In addition, the content control unit 310 moves the emergency image vertically and horizontally with respect to an image (emergency image) that needs to be urgently notified to the driver, for example. For example, the content control unit 310 vibrates the emergency image in the left-right direction. In addition, the content control unit 310 vibrates the emergency image in the vertical direction, for example. Information S ₄ for moving the display image, not illustrated interface is sent to the reflecting mirror driving unit 300.

  The reflection mirror drive unit 300 drives the reflection mirror 220 in the same manner as the reflection mirror drive unit 230. Further, the reflection mirror drive unit 300 determines whether or not the driver has viewed the video by a method described later.

  Further, the reflection mirror drive unit 300 can issue a warning when it is determined that the driver is not viewing the video. This warning is, for example, a warning sound emitted by a device (not shown). With this warning sound, the virtual image display device 12 can inform the driver that information is being displayed.

  The virtual image display device 12 can not only show the video to the driver but also determine whether the driver has seen the video. Thereby, for example, when the driving support information displayed on the windshield 240 is information indicating a warning, the virtual image display device 12 can contribute to the driver's safe driving.

  FIG. 6 is a schematic diagram when the video content 280A is moved left and right (in the y-axis direction) by the content control unit 310. The video content 280A indicates the contents of an image displayed by the virtual image display device 12 as a virtual image. Here, the video content 280A is an emergency image.

  FIG. 7 is an explanatory diagram showing operations of the driver's eyes 260 and the reflection mirror driving unit 300 when the driver visually recognizes the video content 280A that moves to the left and right.

  As shown in FIG. 7, when the driver's eye 260 moves, the synchronization unit 250 moves in synchronization with the driver's eye 260. In FIG. 7, the driver's eyes 260 are moving in the left-right direction (y-axis direction).

The reflection mirror drive unit 300 adjusts the angle of the reflection mirror 220 by feedback control so that the detection light 211 is irradiated to the position of the driver's eyes 260. The control unit 270 sends a signal S ₂ for tilting the reflection mirror 220 in the left-right direction to the reflection mirror drive unit 300 in accordance with the movement of the driver's eyes 260.

That is, when the video content 280A moves in the y-axis direction, the reflection mirror drive unit 300 receives an instruction to tilt the reflection mirror 220 in the left-right direction from the control unit 270. Reflecting mirror driving unit 300, by determining whether or not the signal S ₂ and the signal S ₄ is integrated, it is possible for the driver to determine whether viewed video content 280A. Here, the signal _{S 4} includes movement information of the video content 280A.

  FIG. 7 shows a case where the video content 280A has moved in the y-axis direction. However, the present invention can also be applied when the video content 280A moves in the z-axis direction. In this case, one set of the reflection type elements 251 in the synchronization unit 250 is added. That is, the synchronization unit 250 includes the reflective element 251 corresponding to the z-axis direction and the reflective element 251 corresponding to the y-axis direction. The grooves of the diffraction grating of the reflective element 251 corresponding to the z-axis direction are arranged in the z-axis direction.

  FIG. 8 is a diagram schematically showing the relationship between the moving amount of the video content 280A and the moving amount of the synchronization unit 250. As shown in FIG. The horizontal axis indicates time. The vertical axis indicates the movement amount of the video content 280A and the movement amount of the synchronization unit 250.

Movement amount of information of the synchronization unit 250 is included in the signal S _2. Movement amount of information of the video content 280A is included in the signal _{S 4.}

  FIG. 8 shows a case where the video content 280A moves with a sine wave with time. Here, it is determined whether or not the movement of the synchronization unit 250 is linked to the movement of the video content 280A after the video content 280A has moved and a predetermined time has elapsed. In FIG. 8, the reflection mirror drive unit 300 compares the movement of the video content 280A and the movement of the synchronization unit 250 from the point in time when the vibration of the video content 280A ends for one cycle.

In FIG. 8, the predetermined time is from time T ₀ to time T ₁ . Time _{T 0} is the reflection mirror driving unit 300 is a time of receiving the movement information of the video content 280A. Time _{T 1} is the time when the movement of the video content 280A is completed one cycle. The time T ₁ is the time when the reflecting mirror driving unit 300 starts to determine. Time T _2, is the time at which the reflection mirror driving unit 300 ends the determination.

  This is because there is a delay from when the video content 280A moves until the driver recognizes the movement of the video content 280A. During this time, the reflection mirror drive unit 300 does not make a determination.

When the determination of the reflection mirror drive unit 300 is started, the reflection mirror drive unit 300 accumulates information on the amount of movement of the video content 280A and information on the amount of movement of the synchronization unit 250. In the case of FIG. 8, the reflection mirror driving unit 300 accumulates 12 pieces of movement amount information from time T ₁ to time T ₂ .

  In FIG. 8, movement amounts 280A [0], 280A [1],..., 280A [11] indicate twelve movement amounts of the video content 280A. Further, movement amounts 250 [0], 250 [1],..., 250 [11] indicate 12 movement amounts of the synchronization unit 250.

  Whether or not the movement of the synchronization unit 250 is linked to the movement of the video content 280A is determined by whether or not the following expression (2) is satisfied for each movement amount 250 [i] and 280 [i], for example. . The constant M is a real number for converting the movement amount of the synchronization unit 250 into the movement amount of the video content 280A. The constant N is a real number. The variable i indicates the number of data to be measured for one period of vibration of the video content 280A. In FIG. 8, it is an integer from 0 to 11.

  In any one of the variables i from 0 to 11, when the expression (2) is not satisfied, the virtual image display device 12 determines that the driver is not viewing the video content 280A. When it is determined that the driver is not watching the video content 280A, the virtual image display device 12 generates, for example, a warning sound by a device (not shown).

  Note that the method for determining whether the movement of the synchronization unit 250 is linked to the movement of the video content 280A is not limited to the determination method in FIG.

  As described above, in the virtual image display device 12, the driver determines the video content 280A (emergency image) by determining whether or not the movement of the synchronization unit 250 is interlocked with the movement of the video content 280A. Judge whether or not you saw. The reflection mirror drive unit 300 outputs a warning sound, for example, when it is determined that the driver is not viewing the video content 280A (emergency image). For this reason, the virtual image display device 12 can contribute to the driver's safe driving.

  In addition, although embodiment of this invention was described as mentioned above, this invention is not limited to these embodiment. Moreover, the virtual image display apparatuses 11 and 12 can be utilized as HUDs, such as a motor vehicle, for example. Moreover, it can utilize in various fields, such as not only a motor vehicle but a train, an airplane, or a medical field.

10, 11, 12 Virtual image display device, 20 light source unit, 100, 200, 210 light source unit, 101, 201 image light, 110, 220 reflection mirror, 120, 230, 300 reflection mirror drive unit, 130, 240 windshield, 140 , 260 Driver's eye, 150, 280 Virtual image, 160, 290, 310 Content control unit, 211 Detection light, 212 Reflected light, 212a, 212b, 212c, 212d, 212e, 212f Reflected light spot, 250 Sync unit, 251 reflective element 252 convex lens, 253 sensor, 253a, 253b divided windows, 254 subtractor 270 control unit, 271 control filter, 272 drive amplifier, 280A video _{content, S 1, S 1a, S} 1b, S 1c, S 2 , _S 3, _{S 4} Sa, Sb, Sc, Sd, Se, Sf signal, spacing tp _{groove, T 0, T 1, T} 2 times, M, N constants.

Claims (5)

A light source that emits detection light for detecting the position of the eyes of the person viewing the virtual image;
A synchronization unit that moves in synchronization with the eye;
A reflection mirror for adjusting the optical path of the image light including the virtual image information and the detection light;
A reflection mirror drive unit for adjusting a reflection angle of the reflection mirror;
The synchronization unit includes a reflective element in which convex and concave surfaces are alternately arranged, a convex lens, and a sensor,
The reflective element reflects the detection light incident via the convex lens,
The virtual image display device, wherein the sensor receives detection light reflected by the reflective element, and generates a sensor signal for the reflective mirror drive unit to control the reflective mirror. The virtual image display device according to claim 1, wherein the synchronization unit is installed at a position that is linear with respect to a position of an eye of a person who visually recognizes the virtual image. The virtual image display device according to claim 1, wherein the sensor signal is generated when light emitted from the light source crosses the reflective element. 4. The virtual image display device according to claim 1, wherein the reflection mirror driving unit further has a determination function of determining whether a person who visually recognizes the virtual image has viewed an image. 5. A content control unit;
The content control unit moves the content, which is information of the virtual image, up and down or left and right on the display surface of the virtual image,
The determination function determines whether or not the synchronization unit has moved in conjunction with the content. If the synchronization unit is interlocked, it is determined that a person viewing the virtual image has seen the video, and if not, the virtual image is visually recognized. 5. The virtual image display device according to claim 4, wherein the virtual image display device has a function of determining that a person who is performing is not watching an image and issuing a warning.

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