JP2015197496A - virtual image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a virtual image display device that uses a screen with a micro-lens array, and can create a high-image quality virtual image without the occurrence of distortion of the virtual image to be created, even when a video projection surface of the screen is arranged to be inclined to a light path of a projector.SOLUTION: A virtual image display device projects a video output from a projector 4 to a screen 5 and reflects the video projected on the screen 5 on a windshield 6 of a vehicle 2 so as for a driver 7 of the vehicle to visually recognize the video, and thereby creating a virtual image 8 of the video that is visually recognized by the driver 7 of the vehicle. The screen 5 is made movable so that the angle of the screen 5 relative to a light path of the projector 4 can be changed, and the direction of radiation to radiate laser beams from the projector 4 to the screen 5 is controlled on the basis of the angle of the screen 5 relative to the light path of the projector 4.

Description

  The present invention relates to a virtual image display device that displays a virtual image visually recognized by a user.

  Conventionally, various means have been used as information providing means for providing driving information such as route guidance and obstacle warnings to passengers of moving bodies such as vehicles. For example, display on a liquid crystal display installed on a moving body, sound output from a speaker, and the like. In recent years, as one of such information providing means, a head-up display device (hereinafter referred to as HUD) is used in a space different from a position where an image is actually displayed using an illusion of human eyes. There is a virtual image display device for visually recognizing an image.

  For example, in Japanese Patent Laid-Open No. 2008-76541, the virtual image display device is applied to a display device installed on an instrument panel of a vehicle, driving information (for example, speed display, route guidance display, etc.) is generated as a virtual image, and driving is performed. It is described about making a person visually recognize.

Japanese Patent Laying-Open No. 2008-76541 (page 5-6, FIG. 1)

  Here, in order to provide more effective information by the virtual image display device, it is important to appropriately set the position (more specifically, the distance from the occupant to the virtual image) where the virtual image is generated. For example, in the technique of Patent Document 1 described above, a microlens array that is a screen on which an image is projected is inclined and a virtual image of an arrow that guides a right or left turn of a road is inclined from the near side to the far side. It is described that the image is generated as a typical image.

  Moreover, in the said patent document 1, the microlens array which arranged many lenses in the grid | lattice form is used as a screen. Here, the microlens array is more effective in reducing speckle noise than other general transmissive screens, but in order to generate an appropriate virtual image without distortion or the like, a projector as a light source It is necessary to maintain a proper positional relationship. Specifically, as shown in FIG. 19, if laser light 102 is irradiated near the center of each lens 101 constituting the microlens array, a high-quality virtual image without distortion can be generated. When the laser beam is irradiated, distortion or the like occurs in the generated virtual image. However, in the above-mentioned patent document 1, since the microlens array is disposed at an inclination, there is a problem that it is difficult to maintain the positional relationship with the projector appropriately. As a result, the generated virtual image is distorted.

  The present invention has been made to solve the above-described conventional problems, even when a microlens array screen is used and the screen image projection surface is inclined with respect to the optical path of the projector. An object of the present invention is to provide a virtual image display device that can generate a high-quality virtual image without causing distortion or the like in the generated virtual image.

  In order to achieve the above object, a virtual image display device (1) according to the present invention includes a transmissive screen (5) composed of a microlens array and a projector (4) that projects an image generated based on laser light onto the screen. ), Virtual image generating means (6, 10, 11) for generating a virtual image of the video from the video projected on the screen, and moving the screen, the video with respect to the optical path of the projector is projected Based on the screen moving means (24) for changing the angle of the image projection surface (22), which is the surface of the screen, and the angle of the image projection surface with respect to the optical path of the projector, the laser light is transmitted from the projector to the screen. And an irradiation control means (31) for controlling the irradiation direction of irradiation.

According to the virtual image display device according to the present invention having the above-described configuration, it is generated even when the screen of the microlens array is used and the image projection surface of the screen is arranged to be inclined with respect to the optical path of the projector. It is possible to generate a high-quality virtual image without causing distortion or the like in the virtual image. Further, in a state where the image projection surface of the screen is tilted with respect to the optical path of the projector, it is possible to displace the distance from the user to the virtual image generated by the position where the image is projected onto the screen. As a result, when an image related to an object such as an obstacle or an intersection whose distance from the user is displaced is displayed as a virtual image superimposed on the object, the virtual image is displayed at an appropriate position according to the distance from the user to the object. Can be generated.
Further, by changing the angle of the image projection surface of the screen, it is possible to arbitrarily set the distance from the user of the virtual image that can be generated based on the image projected on the screen. For example, if the inclination angle of the screen with respect to the optical path of the projector is increased, it is possible to generate a virtual image up to a wider range with a distance from the user. As a result, it is possible to generate a virtual image at a necessary position according to the user's situation.

It is the figure which showed the installation aspect to the vehicle of HUD which concerns on this embodiment. It is the figure which showed the internal structure of HUD which concerns on this embodiment. It is the figure which showed the structure of the projector. It is the figure which showed the screen. It is the figure which showed the rotation aspect of a screen. It is the figure which showed the relationship between the light output from a projector, and a screen. It is a figure explaining the production | generation distance of the virtual image in the state by which the screen was inclined and arrange | positioned. It is the figure which showed the virtual image visually recognized from the passenger | crew of a vehicle. It is the block diagram which showed the structure of HUD which concerns on this embodiment. It is a flowchart of the virtual image generation processing program which concerns on this embodiment. It is the figure which showed an example of the angle setting table. It is the figure which showed the number of the lenses used as the object irradiated with a laser beam for every angle of a screen. It is the figure which showed the relationship between a micro lens array and a laser beam. It is the figure which showed the correction | amendment aspect of the irradiation direction of a laser beam for every angle of a screen. It is a figure explaining the relationship between the inclination of a screen and the distortion of an image | video. It is a figure explaining the output correction of a projector. It is the figure which showed an example of the virtual image which can be visually recognized from the passenger | crew of a vehicle when a vehicle stops. It is the figure which showed an example of the virtual image which can be visually recognized from the passenger | crew of a vehicle at the time of driving | running | working of a vehicle. It is a figure explaining the problem of the prior art.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a virtual image generating device according to the invention will be described in detail with reference to the drawings with regard to an embodiment embodied in a head-up display device mounted on a vehicle.

  First, the configuration of a head-up display device (hereinafter referred to as HUD) 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram showing an installation mode of the HUD 1 according to the present embodiment on the vehicle 2.

  As shown in FIG. 1, the HUD 1 is installed inside the dashboard 3 of the vehicle 2, and includes a projector 4 and a screen 5 on which an image from the projector 4 is projected. Then, the image projected on the screen 5 is reflected on the front window 6 in front of the driver's seat through the mirror and Fresnel lens provided in the HUD 1 as will be described later, and is made visible to the passenger 7 of the vehicle 2. ing. Note that the image projected on the screen 5 includes information related to the vehicle 2 and various information used for assisting the driving of the occupant 7. For example, warnings for obstacles (other vehicles and pedestrians), guidance information set by the navigation device and guidance information based on the guidance route (such as arrows indicating the direction of turning left and right), current vehicle speed, guidance signs, map images, traffic information, There are news, weather forecast, time, screen of connected smartphone, TV program and so on.

  Further, in the HUD 1 of the present embodiment, when the occupant 7 visually recognizes an image projected on the screen 5 by reflecting the front window 6, the occupant 7 is not at the position of the front window 6 but at the front of the front window 6. An image projected on the screen 5 at a distant position is configured to be visually recognized as a virtual image 8. The virtual image 8 that can be seen by the occupant 7 is an image projected on the screen 5, but the vertical direction is reversed because the image is projected through the mirror. In addition, the size is changed by using a Fresnel lens.

  Here, regarding the position where the virtual image 8 is generated, more specifically, the distance L from the occupant 7 to the virtual image 8 (hereinafter referred to as a generation distance) L, the shape and position of the mirror and Fresnel lens provided in the HUD 1, and the screen 5 with respect to the optical path It is possible to appropriately set the position depending on the position. In particular, in the present embodiment, the angle of the image projection surface of the screen 5 with respect to the optical path of the projector 4 can be changed as will be described later. In a state where the image projection surface of the screen 5 is inclined with respect to the optical path of the projector 4, the generation distance L can be appropriately changed depending on the inclination angle and the position where the image is projected within the image projection surface. . For example, the generation distance L can be changed between 2.5 m and 20 m.

  Next, a more specific configuration of the HUD 1 will be described with reference to FIG. FIG. 2 is a diagram showing an internal configuration of the HUD 1 according to the present embodiment.

  As shown in FIG. 2, the HUD 1 basically includes a projector 4, a screen 5, a reflection mirror 10, a mirror 11, a Fresnel lens 12, a control circuit unit 13, and a CAN interface 14.

  Here, the projector 4 is an image projection apparatus using an LED light source as a light source, and is, for example, a laser scanning projector.

  FIG. 3 is a diagram showing the configuration of the projector 4. As shown in FIG. 3, the projector 4 includes a laser light source 15 inside. For example, in a laser scanning projector, the laser light output from the light source 15 is reflected by the MEMS mirror 16 and scanned on the screen 5. As a result, a desired image is projected onto the screen 5.

  On the other hand, the screen 5 is a projection medium on which an image projected from the projector 4 is projected, and a transmission screen composed of a microlens array in which a large number of lenses are arranged in a lattice shape is used. Here, FIG. 4 is a diagram showing the screen 5.

  As shown in FIG. 4, the screen 5 has a projection area 22 as a video projection surface on which a video is projected, and a video is generated based on the laser light projected from the projector 4. Further, the screen 5 is configured to be able to change the angle of the projection area 22 with respect to the optical path of the projector 4 by rotating about one side as a rotation axis. Specifically, the screen 5 is rotated around the rotation axis P as shown in FIG. 5 by driving the screen rotation drive motor 24 on the side surface of the screen 5. The position of the rotation axis P is the upper end of the screen 5, and the range in which the screen 5 can be rotated is from the position A where the projection area 22 is perpendicular to the optical path to the projector 4 with respect to the vertical direction. This is a range up to a position B that forms an angle θmax on the side. That is, the screen 5 is rotated so that the distance from the mirror 11 along the optical path is the shortest on the rotation axis P.

  The angle θmax and the size of the screen 5 can be set as appropriate. However, as shown in FIG. 6, all the light output from the projector 4 is received regardless of the position of the screen 5 between the positions A to B. It is set so that the light output from the projector 4 can be received in the entire area of the projection area 22 when it is in the position B where the inclination angle is the largest and can be received in the projection area 22.

  And in the state which has arrange | positioned the screen 5 so that it may incline with respect to the optical path of the projector 4 as shown in FIG. 7, by changing the position in the projection area 22 of the image 25 projected with respect to the screen 5, 8, it is possible to change the position (specifically, the generation distance L that is the distance from the occupant 7 to the virtual image 8) where the virtual image 8 of the video 25 projected on the screen 5 is generated. . Here, the generation distance L depends on the distance from the mirror 11 to the screen 5 along the optical path. That is, the generation distance L is changed in length depending on the distance from the mirror 11 to the screen 5. For example, when the distance from the mirror 11 to the screen 5 is increased (that is, the distance from the projector 4 is decreased), the generation distance L is increased, and the distance from the mirror 11 to the screen 5 is decreased (that is, the distance from the projector 4). The generation distance L becomes shorter. Accordingly, when the screen 5 is tilted as shown in FIG. 7, the generation distance L of the virtual image 8 of the image 25 projected near the rotation axis P, which is shorter from the mirror 11, is shorter (that is, the occupant 7 The virtual image 8 will be visually recognized closer to. On the other hand, the generation distance L of the virtual image 8 of the image 25 projected at a position away from the rotation axis P where the distance from the mirror 11 becomes long becomes longer (that is, the virtual image 8 is seen farther from the passenger 7. become).

  The range in which the position where the virtual image 8 of the video 25 projected on the screen 5 is generated (specifically, the generation distance L that is the distance from the occupant 7 to the virtual image 8) can be changed is that of the projector 4 It changes depending on the inclination angle of the screen 5 with respect to the optical path. Specifically, when the screen 5 is perpendicular to the optical path of the projector 4, only one generation distance L can be selected, and the generation distance increases as the inclination angle of the screen 5 with respect to the optical path of the projector 4 increases. The range in which L can be changed also increases.

  Here, since the image 25 projected onto the screen 5 is reflected by the reflecting mirror 10 and the mirror 11, the generated virtual image 8 is an image obtained by inverting the image projected onto the screen 5 vertically and horizontally. It becomes. That is, the image 25 projected above the screen 5 close to the rotation axis P, the virtual image 8 generated based on the image 25 is viewed from the occupant 7 in the vertical direction, and the screen 5 away from the rotation axis P. The lower the image 25 projected downward, the more the virtual image 8 generated based on the image 25 is viewed from the passenger 7 in the vertical direction. Therefore, the virtual image 8 generated at a position far from the occupant 7 can be viewed upward from the occupant 7. Here, when the vehicle occupant 7 visually recognizes the front environment through the front window 6, basically, the one located farther away looks higher. Therefore, it becomes possible to make the superimposed display of the virtual image 8 and the front environment easy to see by making the front environment visually recognizable by tilting the screen 5 correspond to the virtual image 8.

  Further, in a state where the screen 5 is arranged so as to be inclined with respect to the optical path of the projector 4, the virtual image 8 generated as shown in FIG. 8 is also inclined with respect to the vertical direction. In particular, the inclination angle becomes larger as the virtual image 8 has a longer generation distance L. As a result, for example, when generating a virtual image 8 such as an arrow indicating the right / left turn direction, the virtual image 8 can be arranged along the road surface.

  In the present embodiment, in particular, in the state where the screen 5 is most inclined with respect to the optical path of the projector 4, the virtual image of the image 25 projected at the position closest to the rotation axis P as shown in FIG. The generation distance L of 8 is 2.5 m, and the generation distance L of the virtual image 8 of the image 25 projected to the farthest position from the rotation axis P is 20 m. Further, in a state where the screen 5 is arranged in the vertical direction with respect to the optical path of the projector 4, the generation distance L is 2.5 m in any virtual image 8 of the image 25 projected at any position in the projection area 22. Design to be

  That is, in the HUD 1 according to the present embodiment, the generation distance L of the virtual image 8 can be changed between 2.5 m and 20 m at the maximum. Further, since the position of the rotation axis P is fixed, the lower limit of the range in which the generation distance L is displaced is 2.5 m regardless of the position of the screen 5 from the position A to the position B. That is, the virtual image 8 with the generation distance L of 2.5 m can always be generated regardless of the angle of the screen 5. Here, a distance of 2.5 m from the occupant 7 is a distance that is unlikely to overlap with the vehicle ahead, and information such as a vehicle speed that does not require the generation distance to be displaced, warning information that the user needs to make sure to visually recognize, etc. Is generated at a position where the generation distance L is 2.5 m.

  The screen rotation drive motor 24 is a stepping motor. Then, the HUD 1 controls the screen rotation drive motor 24 based on the pulse signal transmitted from the control circuit unit 13 and can appropriately position the angle of the screen 5 with respect to the set angle.

  On the other hand, the reflecting mirror 10 is a reflecting plate that reflects an image projected from the projector 4 to change the optical path and projects it onto the screen 5 as shown in FIG.

  Further, the mirror 11 reflects the image light from the screen 5 as shown in FIG. 2, and causes the occupant 7 to visually recognize the image of the screen 5 through the front window 6. 1), and constitutes a virtual image generating means together with the reflecting mirror 10 and the front window 6. As the mirror 11, a spherical concave mirror, an aspheric concave mirror, or a free-form curved mirror for correcting distortion of a projected image is used. Since the image projected on the screen 5 is reflected by the reflecting mirror 10 and the mirror 11, the generated virtual image is an image obtained by inverting the image projected on the screen 5 vertically and horizontally.

  The Fresnel lens 12 is a magnifying glass for generating a virtual image 8 by enlarging the image projected on the screen 5 as shown in FIG. And in HUD1 which concerns on this embodiment, the image | video projected on the screen 5 is further reflected on the front window 6 via the mirror 11 and the Fresnel lens 12, and is made to be visually recognized by the passenger | crew 7, so that the front of the front window 6 is visible. The image projected on the screen 5 at a distant position is enlarged and is visually recognized by the occupant as a virtual image 8 (see FIG. 1).

  The control circuit unit 13 is an electronic control unit that controls the entire HUD 1. Here, FIG. 9 is a block diagram showing a configuration of the HUD 1 according to the present embodiment.

  As shown in FIG. 9, the control circuit unit 13 includes a CPU 31 as an arithmetic device and a control device, a RAM 32 used as a working memory when the CPU 31 performs various arithmetic processes, a control program, and a virtual image generation described later. A ROM 33 in which a processing program (see FIG. 10) and the like are recorded, an internal storage device such as a flash memory 34 for storing a program read from the ROM 33 and an angle setting table to be described later are provided. The control circuit unit 13 is connected to the projector 4 and the screen rotation drive motor 24, respectively, and performs drive control of the projector 4 and various motors.

  The CAN (controller area network) interface 14 is an interface for inputting / outputting data to / from CAN which is an in-vehicle network standard for performing multiplex communication between various on-vehicle devices installed in a vehicle and control devices for vehicle equipment. It is. The HUD 1 is connected to a control device (for example, the navigation device 48, the AV device 49, etc.) of various vehicle-mounted devices and vehicle equipment via the CAN so as to be able to communicate with each other. Accordingly, the HUD 1 is configured to be able to project output screens of the navigation device 48, the AV device 49, and the like.

  Next, a virtual image generation processing program executed by the CPU 31 in the HUD 1 having the above configuration will be described with reference to FIG. FIG. 10 is a flowchart of the virtual image generation processing program according to the present embodiment. Here, the virtual image generation processing program is a program that is executed after the ACC of the vehicle is turned on, and generates a virtual image that is visible to the user who is a vehicle occupant while displacing the angle of the screen 5 according to the state of the vehicle. . Note that the program shown in the flowchart of FIG. 10 below is stored in the RAM 32 or ROM 33 provided in the HUD 1 and executed by the CPU 31. Further, in the present embodiment, when the vehicle ACC is turned on, the angle of the screen 5 is set so that the screen 5 is perpendicular to the optical path of the projector 4 (position A in FIG. 6). explain.

  First, in step (hereinafter abbreviated as S) 1 in the virtual image generation processing program, the CPU 31 determines whether or not the vehicle is in a traveling state. For example, a vehicle speed sensor is used to determine whether or not the vehicle is running.

  If it is determined that the vehicle is in a traveling state (S1: YES), the process proceeds to S4. On the other hand, when it is determined that the vehicle is not in a traveling state, that is, in a stopped state (S1: NO), the process proceeds to S2.

  In S2, the CPU 31 does not need to generate a virtual image particularly far away because the vehicle is in a stopped state, so the position of the screen 5 for generating the virtual image 8 to a position where the virtual image 8 needs to be generated (hereinafter, referred to as the virtual image 8). Is set to a position where the maximum generation distance X is the shortest “2.5 m”. Here, the maximum generation distance X is the maximum generation distance of the virtual image 8 that can be generated by the screen 5. As described above, in the HUD 1 according to the present embodiment, the screen 5 can be disposed to be inclined with respect to the optical path of the projector 4, and in this case, the position of the image projected on the screen 5 in the projected area 22 is determined. By changing, it is possible to change the generation distance L as shown in FIGS. In this embodiment, the generation distance L of the virtual image 8 of the image projected at the position farthest from the rotation axis P is the maximum generation distance X. The position where the maximum generation distance X is “2.5 m” is a position where the screen 5 is perpendicular to the optical path of the projector 4 (position A in FIG. 6).

  Next, in S3, the CPU 31 performs output setting of the laser beam by the projector 4 corresponding to the target screen position set in S2 (position where the maximum generation distance X = 2.5 m). The projector 4 corrects the irradiation direction of the laser light to be output and the image generated by the laser light as described later based on the set output setting of the laser light. Thereafter, the process proceeds to S9.

  On the other hand, in S4, the CPU 31 determines whether or not the target generation distance T of the virtual image 8 is longer than 20 m that is the upper limit of the maximum generation distance X that can be set in the HUD 1 according to the present embodiment. Here, the target generation distance T is the distance from the vehicle occupant 7 to the position where the virtual image 8 should be generated for the current vehicle. Further, the position where the virtual image 8 should be generated is determined according to the situation of the traveling vehicle. For example, when a point where traveling guidance such as a guidance intersection needs to be approached, the position becomes the position of the preceding vehicle and When a warning is given to an obstacle such as a person, it becomes the position of the obstacle.

  When it is determined that the target generation distance T is longer than 20 m (S4: YES), the process proceeds to S7. On the other hand, when it is determined that the target generation distance T is 20 m or less (S4: NO), the process proceeds to S5.

  In S <b> 5, the CPU 31 sets the target screen position to a position where the maximum generation distance X is “target generation distance T”.

  Next, in S6, the CPU 31 performs output setting of laser light by the projector 4 corresponding to the target screen position (position where the maximum generation distance X = Tm) set in S5. The projector 4 corrects the irradiation direction of the laser light to be output and the image generated by the laser light as described later based on the set output setting of the laser light. Thereafter, the process proceeds to S9.

  On the other hand, in S7, the CPU 31 sets the target screen position to a position where the maximum generation distance X is “20 m”. The position where the maximum generation distance X is “20 m” is the position (position B in FIG. 6) where the maximum inclination angle θmax with respect to the optical path of the projector 4 is within the movable range of the screen 5.

  Next, in S8, the CPU 31 performs output setting of the laser beam by the projector 4 corresponding to the position of the screen set in S7 (the position where the maximum generation distance X = 20 m). The projector 4 corrects the irradiation direction of the laser light to be output and the image generated by the laser light as described later based on the set output setting of the laser light. Thereafter, the process proceeds to S9.

  In S9, the CPU 31 determines the angle of the target screen position that realizes the maximum generation distance X set in S2, S5, and S7. An angle setting table stored in the flash memory 34 is used to determine the angle of the screen 5. In the angle setting table, for each maximum generation distance X, an angle of the screen 5 (specifically, an angle with respect to the vertical direction of the optical path of the projector 4) for realizing the maximum generation distance X is defined as shown in FIG. ing. Specifically, the position where the maximum generation distance X is “2.5 m” is the position where the screen 5 is perpendicular to the optical path of the projector 4 (position A in FIG. 6), and the maximum generation distance X is As the length increases, the angle of the projection area 22 of the screen 5 with respect to the vertical direction of the optical path of the projector 4 is specified to gradually increase.

  Next, in S10, the CPU 31 determines the drive amount (number of pulses) of the screen rotation drive motor 24 necessary to rotate the screen 5 from the current position to the angle of the target screen position specified in S9.

  Thereafter, in S <b> 11, the CPU 31 transmits a pulse signal for driving the screen rotation drive motor 24 by the drive amount determined in S <b> 10 to the screen rotation drive motor 24. Then, the screen rotation drive motor 24 that has received the pulse signal drives based on the received pulse signal. As a result, the screen 5 rotates about the rotation axis P to the target screen position.

  Next, in S12, the CPU 31 determines whether or not the rotation of the screen 5 has been completed. Specifically, it is determined that the rotation of the screen 5 has been completed when a signal indicating that the drive has been completed is received from the screen rotation drive motor 24 that transmitted the pulse signal in S11.

  And when it determines with rotation of the screen 5 having been completed (S12: YES), it transfers to S13. On the other hand, when it is determined that the rotation of the screen 5 is not completed (S12: NO), the process waits until the rotation is completed.

  In S <b> 13, the CPU 31 inputs an image to be projected onto the screen 5 by the projector 4. The video projected by the projector 4 includes information related to the vehicle 2 and various information used for assisting the driving of the occupant 7. For example, warnings for obstacles (other vehicles and pedestrians), guidance information set by the navigation device and guidance information based on the guidance route (such as arrows indicating the direction of turning left and right), current vehicle speed, guidance signs, map images, traffic information, There are news, weather forecast, time, connected smart phone screen, TV screen and so on. In particular, in the present embodiment, when the vehicle is stopped, an image of the current vehicle speed of the vehicle and a TV screen are projected out of the above images, and when the vehicle is traveling, warnings for obstacles and guidance routes set by the navigation device The guidance information based on the guidance route is output.

  Next, in S14, the CPU 31 transmits a control signal to the projector 4, and corrects the laser light irradiation direction by the projector 4 based on the laser light output setting of the projector 4 set in S3, S6, and S8. . Specifically, based on the angle of the screen 5 with respect to the optical path of the projector 4, the range in which the screen 5 is irradiated with the laser light and the number of pixels (resolution) of the image generated by the laser light are corrected.

  Here, as shown in FIG. 12, the projection range 50 of the laser beam onto the screen 5 changes depending on the inclination angle of the screen 5 with respect to the optical path of the projector 4. More specifically, a position close to the projector 4 is projected to a range that is reduced more than a far position. Accordingly, when the screen 5 is in a direction perpendicular to the optical path of the projector 4, the projection range 50 has a rectangular shape, but when the screen 5 is inclined, the projection range 50 has a trapezoidal shape with the upper side longer than the lower side. . Moreover, the projection range 50 in the direction perpendicular to the rotation axis P becomes narrower as the inclination angle of the screen 5 becomes smaller.

  Accordingly, the number of lenses included in the projection range 50 (that is, the number of lenses to be irradiated with laser light) also changes according to the projection range 50. For example, a case where the number of lenses constituting the screen 5 is 1280 in the parallel direction (lateral direction) of the rotation axis P and 800 in the vertical direction (longitudinal direction) will be described as an example. Thus, when the screen 5 is in a direction perpendicular to the optical path of the projector 4, the lenses to be irradiated with the laser light are in a range of 1280 × 700 rectangles. On the other hand, when the screen 5 is tilted up to the maximum angle (θmax) with respect to the optical path of the projector 4, the number of lenses to be irradiated with the laser light is a trapezoid having 1280 upper sides, 1000 lower sides, and 800 heights. It becomes a range.

  Here, when a microlens array is used as the screen 5, the laser beam 52 is not irradiated on the boundary between the lenses 51 constituting the microlens array as shown in FIG. When the light 52 is irradiated, a high-quality virtual image without distortion can be generated. For this purpose, it is necessary to control the irradiation direction so that the number of lenses of the screen 5 irradiated per laser beam is fixed. For example, the irradiation direction of the laser beam is controlled so that the relationship between the laser beam and the number of irradiated lenses is 1: 1, 1: 2, or 1: 3.

  Below, the example which controls the irradiation direction which irradiates a laser beam so that the relationship between a laser beam and the number of irradiated lenses may be set to 1: 1 is demonstrated. For example, as shown in FIG. 14, when the screen 5 is in a direction perpendicular to the optical path of the projector 4, the irradiation range 53 of the laser beam is rectangular, and the number of pixels of the image generated by the laser beam is the rotation axis P. The irradiation direction is controlled so that the number of pixels in the parallel direction becomes 1280 dots. In other words, the image has a constant resolution in the entire area. Further, the irradiation direction is controlled so that the vertical direction becomes 700 dots corresponding to the number of lenses of the screen 5 irradiated with laser light in the same vertical direction. As a result, the relationship between the laser light and the number of irradiated lenses can be 1: 1.

  On the other hand, when the screen 5 is tilted up to the maximum angle with respect to the optical path of the projector 4, the laser beam irradiation range 53 is a trapezoid that is widened to the lower side as compared to the vertical direction. Thereby, it is possible to fix the number of lenses of the screen 5 irradiated with laser light in the parallel direction of the rotation axis P to 1280. Further, the irradiation direction is controlled so that the number of pixels of the image generated by the laser light is 1280 dots regardless of the irradiation range of the number of pixels in the parallel direction of the rotation axis P. That is, the resolution is reduced toward the lower side of the trapezoid. Further, the irradiation direction is controlled so that the vertical direction is 800 dots corresponding to the number of lenses of the screen 5 irradiated with laser light in the same vertical direction. As a result, the relationship between the laser light and the number of irradiated lenses can be 1: 1.

  Next, in S15, the CPU 31 transmits a control signal to the projector 4, and corrects the image input in S13 based on the laser light output setting of the projector 4 set in S3, S6, and S8.

  Here, when the screen 5 is inclined with respect to the optical path of the projector 4 as shown in FIG. 15, the image 25 projected on the screen 5 is distorted. Specifically, the position close to the projector 4 is projected with being reduced than the position far away. For example, when a rectangular image is output from the projector 4, the same rectangular image 55 is drawn on the screen when the screen 5 is perpendicular to the optical path of the projector 4. Is inclined with respect to the optical path of the projector 4, a trapezoidal image 56 whose upper side is longer than the lower side is drawn on the screen. Further, the distortion of the image 56 increases as the inclination angle of the screen 5 increases.

  Therefore, when the screen 5 is tilted with respect to the optical path of the projector 4, as shown in FIG. 16, when the image is projected onto the screen 5, the image 56 corrected by performing reverse calculation so as to have the original shape is projected. There is a need. For example, in order to generate the virtual image 8 of the rectangular image, the laser light projection range related to the image 57 is corrected and output so that the upper side becomes a trapezoidal image 57 shorter than the lower side. The correction amount increases as the tilt angle of the screen 5 increases.

  Next, in S16, the CPU 31 projects the image corrected in S15 on the screen 5 from the projector 4 based on the irradiation direction of the laser light corrected in S14.

As a result, for example, when the vehicle is stopped, a numerical value indicating the current vehicle speed and a television screen are generated as a virtual image 8 near the lower edge of the front window 6 and 2.5 m ahead of the front window 6 as shown in FIG. And is visible from the passenger.
On the other hand, when the vehicle is in a traveling state and an intersection 60 to be turned right and left and a pedestrian 61 as an obstacle approach as shown in FIG. 18, an arrow indicating a right or left turn at the intersection is located at the position of the intersection 60. A virtual image 8 is generated, and a warning virtual image 8 is generated at the position of the pedestrian 61. In addition, by tilting the screen 5, it is possible to make the front environment visually recognized by the occupant 7 correspond to the position of the virtual image 8. For example, in the example shown in FIG. 18, the virtual image 8 of the warning of the pedestrian 61 is generated farther than the virtual image 8 of the arrow indicating the left / right turn of the intersection 60. Therefore, it is possible to make it easy to see the superimposed display of the virtual image 8 and the front environment. If the distance from the occupant 7 to the intersection 60 or the pedestrian 61 to which the vehicle turns is changed due to the subsequent movement of the vehicle, the inclination angle of the screen 5 (that is, the maximum generation distance X) changes accordingly. The position where the virtual image 8 is generated is also changed to an appropriate position.

  Even if the screen 5 is tilted, the generation distance L of the virtual image 8 projected to the position closest to the rotation axis P is 2.5 m, so the virtual image 8 is far away at the intersection 60 or the pedestrian 61. When there is warning information that needs to be surely recognized by the user while generating a virtual image 8, a virtual image 8 of the warning information may be generated simultaneously at a position where the generation distance L is 2.5 m as shown in FIG. It becomes possible.

As described above in detail, according to the HUD 1 according to the present embodiment, an image output from the projector 4 is projected on the screen 5, and the image projected on the screen 5 is reflected on the front window 6 of the vehicle 2 to By making the occupant 7 visually recognize, a virtual image 8 of an image visually recognized by the occupant 7 of the vehicle is generated. Further, by moving the screen 5, the angle of the screen 5 with respect to the optical path of the projector 4 can be changed, and laser light is irradiated from the projector 4 to the screen 5 based on the angle of the screen 5 with respect to the optical path of the projector 4. Since the irradiation direction to be controlled is controlled (S14, S15), the distance from the user of the virtual image 8 that can be generated based on the image projected on the screen 5 can be arbitrarily set. For example, if the inclination angle of the screen 5 with respect to the optical path of the projector 4 is increased, a virtual image can be generated up to a wider range with a distance from the user. As a result, it is possible to generate a virtual image at a necessary position according to the user's situation.
Even when the screen 5 of the microlens array is used and the projection area 22 of the screen 5 is inclined with respect to the optical path of the projector 4, the generated virtual image 8 is not distorted. It is possible to generate a high-quality virtual image 8. Further, in the state where the projection area 22 of the screen 5 is inclined with respect to the optical path of the projector 4, the distance to the virtual image 8 generated by the user can be displaced depending on the position of projecting the image on the screen 5. It becomes. As a result, when an image related to an object such as an obstacle or an intersection whose distance from the user is displaced is displayed as a virtual image superimposed on the object, the virtual image is displayed at an appropriate position according to the distance from the user to the object. Can be generated.

Note that the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the scope of the present invention.
For example, in the present embodiment, the virtual image is generated in front of the front window 6 of the vehicle 2 by the HUD 1, but the virtual image may be generated in front of a window other than the front window 6. In addition, the object to be reflected by the HUD 1 may be a visor (combiner) installed around the front window 6 instead of the front window 6 itself.

  In the present embodiment, the HUD 1 is installed on the vehicle 2. However, the HUD 1 may be installed on a moving body other than the vehicle 2. For example, it can be installed on a ship or an aircraft. Moreover, you may install in the ride type attraction installed in an amusement facility. In that case, a virtual image can be generated around the ride so that the rider can visually recognize the virtual image.

  Moreover, although this embodiment demonstrated the example which applied the virtual image production | generation apparatus to HUD1, if it is an apparatus which has a structure which produces | generates a virtual image and makes a user visually recognize, it is applicable besides HUD. For example, you may apply to the display apparatus installed in the instrument panel.

  In the present embodiment, the rotation range of the screen 5 is set to a range from a position A where the screen 5 is perpendicular to the optical path of the projector 4 to a position B which forms an angle θmax with respect to the vertical direction, and The position B is set to a position where the generation distance L can be changed between 2.5 m and 20 m, but the rotation range of the screen 5 can be changed as appropriate.

  Further, in the present embodiment, based on the angle of the screen 5 with respect to the optical path of the projector 4, the range in which the laser light is irradiated onto the screen 5 and the number of pixels (resolution) of the video generated by the laser light are corrected. (S14), but only one of them may be corrected.

  In this embodiment, the screen is composed of one screen, but the number of screens may be two or more. Further, when two or more screens are used, all the screens may be arranged to be inclined with respect to the optical path, or only a part of the screens may be arranged to be inclined with respect to the optical path. You may comprise as follows.

  Moreover, although the embodiment which actualized the virtual image generation device according to the present invention has been described above, the virtual image generation device can also have the following configuration, and in this case, the following effects can be obtained.

For example, the first configuration is as follows.
A transmissive screen comprising a microlens array, a projector for projecting an image generated based on laser light onto the screen, a virtual image generating means for generating a virtual image of the image from the image projected on the screen, By moving the screen, a screen moving means for changing an angle of a video projection surface, which is a surface of the screen on which the video is projected with respect to the optical path of the projector, and an angle of the video projection surface with respect to the optical path of the projector. And an irradiation control means for controlling an irradiation direction for irradiating the laser beam from the projector to the screen.
According to the virtual image generating apparatus having the above-described configuration, even if the screen of the microlens array is used and the image projection surface of the screen is arranged to be inclined with respect to the optical path of the projector, the generated virtual image is distorted. Thus, a high-quality virtual image can be generated. Further, in a state where the image projection surface of the screen is tilted with respect to the optical path of the projector, it is possible to displace the distance from the user to the virtual image generated by the position where the image is projected onto the screen. As a result, when an image related to an object such as an obstacle or an intersection whose distance from the user is displaced is displayed as a virtual image superimposed on the object, the virtual image is displayed at an appropriate position according to the distance from the user to the object. Can be generated.
Further, by changing the angle of the image projection surface of the screen, it is possible to arbitrarily set the distance from the user of the virtual image that can be generated based on the image projected on the screen. For example, if the inclination angle of the screen with respect to the optical path of the projector is increased, it is possible to generate a virtual image up to a wider range with a distance from the user. As a result, it is possible to generate a virtual image at a necessary position according to the user's situation.

The second configuration is as follows.
The irradiation control means controls the irradiation direction so that the number of lenses of the screen irradiated per one laser beam is fixed.
According to the virtual image generating apparatus having the above-described configuration, it is possible to irradiate laser light near the center of each lens constituting the microlens array, and it is possible to generate a high-quality virtual image without distortion.

The third configuration is as follows.
The irradiation control means controls the irradiation direction so that the laser beam is not irradiated onto the boundary of each lens constituting the screen.
According to the virtual image generating apparatus having the above-described configuration, it is possible to generate a high-quality virtual image without distortion even when a screen including a microlens array is used.

The fourth configuration is as follows.
The irradiation control unit corrects a range in which the laser beam is irradiated on the screen based on an angle of the image projection surface with respect to an optical path of the projector.
According to the virtual image generating apparatus having the above-described configuration, the number of screen lenses to be irradiated can be adjusted by the laser light by correcting the range irradiated with the laser light, regardless of the angle of the image projection surface. It is possible to fix the number of screen lenses irradiated per laser beam. As a result, a high-quality virtual image without distortion can be generated.

The fifth configuration is as follows.
The screen moving means changes the angle of the image projection surface with respect to the optical path by rotating the screen about one side of the screen as a rotation axis, and the irradiation control means is configured to change the laser in the direction parallel to the rotation axis. The range irradiated with the laser beam is corrected so that the number of lenses of the screen irradiated with light is constant.
According to the virtual image generating apparatus having the above configuration, the angle of the image projection surface of the screen can be changed by an easy configuration and control. Therefore, it is possible to reduce the size and cost of the apparatus. In addition, no matter what angle the screen is with respect to the optical path of the projector, the number of screen lenses irradiated with laser light in the direction parallel to the rotation axis can be made constant. It is possible to fix the number of screen lenses to be irradiated. As a result, a high-quality virtual image without distortion can be generated.

The sixth configuration is as follows.
The irradiation control unit corrects the number of pixels of the video generated by the laser light based on an angle of the video projection surface with respect to an optical path of the projector.
According to the virtual image generating device having the above configuration, the number of screen lenses irradiated per laser beam is fixed regardless of the angle of the image projection surface by correcting the number of pixels of the image generated by the laser beam. It becomes possible to do. As a result, a high-quality virtual image without distortion can be generated.

The seventh configuration is as follows.
The screen moving means changes the angle of the image projection surface with respect to the optical path by rotating the screen about one side of the screen as a rotation axis, and the irradiation control means is generated on the image projection surface. The number of pixels in the vertical direction of the rotation axis of the image is corrected in accordance with the number of lenses of the screen irradiated with the laser light in the vertical direction of the rotation axis.
According to the virtual image generating apparatus having the above configuration, the angle of the image projection surface of the screen can be changed by an easy configuration and control. Therefore, it is possible to reduce the size and cost of the apparatus. Also, no matter what angle the screen is with respect to the optical path of the projector, the number of screen lenses irradiated with laser light in the direction perpendicular to the rotation axis should correspond to the number of pixels (that is, the number of laser light). Therefore, the number of screen lenses irradiated per laser beam can be fixed. As a result, a high-quality virtual image without distortion can be generated.

The eighth configuration is as follows.
The irradiation control unit corrects a projection range of the laser light related to the video so as to correct distortion of the video based on an angle of the video projection surface with respect to an optical path of the projector.
According to the virtual image generating device having the above-described configuration, it is possible to correct image distortion caused by the inclination of the screen and generate a virtual image having an appropriate shape.

The ninth configuration is as follows.
The screen moving means moves the screen within a range in which all light output from the projector is received by the video projection surface.
According to the virtual image generating device having the above-described configuration, it is possible to prevent a part of the virtual image from being interrupted when the screen is moved.

DESCRIPTION OF SYMBOLS 1 Head up display apparatus 2 Vehicle 3 Dashboard 4 Projector 5 Screen 6 Front window 7 Crew 8 Virtual image 24 Screen rotation drive motor 25 Image | video 31 CPU
32 RAM
33 ROM
34 Flash memory 51 Lens 52 Laser beam 53 Irradiation range

Claims (9)

A transmission screen comprising a microlens array;
A projector that projects an image generated based on laser light onto the screen;
Virtual image generating means for generating a virtual image of the video from the video projected on the screen;
Screen moving means for changing an angle of an image projection surface which is a surface of the screen on which the image is projected with respect to an optical path of the projector by moving the screen;
A virtual image display device comprising: irradiation control means for controlling an irradiation direction of irradiating the laser light from the projector to the screen based on an angle of the video projection surface with respect to an optical path of the projector.   The virtual image display device according to claim 1, wherein the irradiation control unit controls the irradiation direction so that the number of lenses of the screen irradiated per one laser beam is fixed.   3. The virtual image display device according to claim 1, wherein the irradiation control unit controls the irradiation direction so that the laser beam is not irradiated on a boundary between the lenses constituting the screen. 4.   The said irradiation control means correct | amends the range in which the said laser beam is irradiated with respect to the said screen based on the angle of the said image projection surface with respect to the optical path of the said projector. The virtual image display device according to any one of the above. The screen moving means changes the angle of the image projection surface with respect to the optical path by rotating the screen about one side of the screen as a rotation axis,
The said irradiation control means correct | amends the range irradiated with the said laser beam so that the number of lenses of the said screen irradiated with the said laser beam may become fixed in the parallel direction of the said rotating shaft. 4. The virtual image display device according to 4.   The said irradiation control means correct | amends the pixel number of the said image | video produced | generated with the said laser beam based on the angle of the said image projection surface with respect to the optical path of the said projector. The virtual image display device according to claim 1. The screen moving means changes the angle of the image projection surface with respect to the optical path by rotating the screen about one side of the screen as a rotation axis,
The irradiation control means corresponds to the number of pixels in the vertical direction of the rotation axis of the image generated on the image projection surface, corresponding to the number of lenses of the screen irradiated with the laser light in the vertical direction of the rotation axis. The virtual image display device according to claim 6, wherein correction is performed.   The said irradiation control means correct | amends the projection range of the laser beam which concerns on the said image | video so that the distortion of the said image | video may be corrected based on the angle of the said image projection surface with respect to the optical path of the said projector. Item 8. The virtual image display device according to any one of Items 7.   9. The virtual image display device according to claim 1, wherein the screen moving unit moves the screen within a range in which all light output from the projector is received by the video projection surface. 10. .

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