JP6598686B2 - Image projection apparatus, image projection method, and image projection program - Google Patents

Description

  The present invention relates to an image projection apparatus that projects an image, and more particularly, to an image projection apparatus that projects an image on a windshield of a vehicle.

  As one means for displaying driving support information for supporting the driver, a head-up display (hereinafter abbreviated as HUD) has been put into practical use. A typical HUD projects an image on a windshield from a projection device installed in a car or a screen provided on the windshield, and it appears to the driver as if an object exists in the real space through the windshield. A virtual image. When the HUD is used, the driving support information can be displayed in the driver's line-of-sight direction, so that the driver's line-of-sight movement can be reduced as compared with the case of viewing a liquid crystal display or the like in the vehicle.

  The HUD can adjust the size and position of the projected image by adjusting the focal length of the projection optical system. Patent Document 1 discloses a HUD that displays a plurality of images at different positions by moving the position of a screen or a projection lens, or displays a single large image at the time of parking.

JP2015-11217A

  As described in Patent Document 1, it is possible to display a plurality of images having different focal lengths on the windshield by HUD. FIG. 17A is a display example during traveling, FIG. 17B is a display example when the vehicle is stopped, and FIGS. 18A and 18B are schematic diagrams when they are shown from the side. It is. For example, as shown in FIG. 17A, when two HUD_A and HUD_B are mounted on the vehicle, an image 1A (for example, speed information) of the focal length f1 is displayed on the windshield by HUD_A while the vehicle is running. The image 1B (for example, the traveling direction) having the focal length f2 is projected onto the windshield by the HUD_B. At this time, as shown in FIG. 18A, the driver U visually recognizes the virtual image 1A 'of the image 1A near the vehicle and visually recognizes the virtual image 1B' of the image 1B far away from the vehicle. The distances from the driver U to the virtual image 1A ′ and the distance 1B ′ are Lf and Ln, and Lf> Ln.

  While the vehicle is stopped, as shown in FIG. 17B, images 2A and 2B are projected onto the focal length f2 by HUD_1A and HUD_1B, and as shown in FIG. 18B, the driver U The virtual image 2A ′ of the image 2A and the virtual image 2B ′ of the image 2B are visually recognized at the positions. For example, the image 2A is a traveling direction, and the image 2B is vehicle speed information. In addition to such display, it is also possible to display a single image X obtained by combining the images 2A and 2B. is there. HUD_A and HUD_B may be two projection optical systems included in one HUD, or may be composed of two HUDs.

  When switching the display of images with different focal lengths as described above is performed in conjunction with the speed of the vehicle or the like, if a traffic jam occurs, the driving / stopping is repeated, and the display is switched each time. If the run / stop cycle is long, I don't care much, but if the cycle becomes short, the display of images with a large focal length and images with a small focal length are frequently switched, The display may be obstructive or the visibility may be reduced.

  The present invention solves such a conventional problem, and provides an image projection device, an image projection method, and an image projection program that suppress a decrease in visibility when an image is projected while changing a focal length. For the purpose.

  An image projection apparatus according to the present invention includes a first projection unit capable of projecting an image by a first projection optical system, a second projection unit capable of projecting an image by a second projection optical system, and a first projection unit A first projection mode in which the projection unit and the second projection unit project an image at a first focal length; a first projection unit that projects an image at a first focal length; and a second projection unit that A second projection mode for projecting an image at a focal length of 2, a vehicle state detection means for detecting a vehicle state, and the first and second projection means based on the detection result of the vehicle state detection means, Switching control means for controlling the switching of the projection mode, and the switching control means sets the first focal length of the first projection means to an intermediate when switching from the second projection mode to the first projection mode. The focal length is changed, and the second focal length of the second projection means is changed to Serial changing the focal length of the intermediate focal length of the intermediate is greater than the first focal length, and is smaller than the second focal length.

  Preferably, the switching control unit further changes the intermediate focal length of the first projection unit to the first focal length, and changes the intermediate focal length of the second projection unit to the first focal length. Let Preferably, when switching from the second projection mode to the first projection mode, the first and second projection means project an image at the intermediate focal length for a certain period. Preferably, the switching control unit changes the first focal length of the first projection unit to an intermediate focal length when switching from the first projection mode to the second projection mode, and the second projection unit The first focal length is changed to an intermediate focal length. Preferably, the switching control unit further changes the intermediate focal length of the first projection unit to the first focal length, and changes the intermediate focal length of the second projection unit to the second focal length. . Preferably, when switching from the first projection mode to the second projection mode, the first and second projection means project images at the intermediate focal length for a certain period. Preferably, the image projection apparatus further includes vehicle state determination means for determining whether the vehicle is in a stopped state or a traveling state based on a detection result of the vehicle state detection unit, and the switching control unit is configured to determine whether the vehicle is in a stopped state. The first projection mode is selected, and the second projection mode is selected when the driving state is determined. Preferably, the switching control unit reconfirms the determination result of the vehicle state determination unit when the first projection unit and the second projection unit are at the intermediate focal length, and there is a change in the determination result. Shifts the first and second projection means to the original projection mode. Preferably, the vehicle state detection unit includes vehicle speed information, and the vehicle state determination unit determines that the vehicle is stopped when the vehicle speed is less than a threshold value, and the vehicle speed is equal to or greater than the threshold value. It is determined that the vehicle is running. Preferably, the switching control means continuously changes the first focal length of the first projection means to the intermediate focal length, and changes the first or second focal length of the second projection means to the intermediate focal length. The focal length is continuously changed. Preferably, the intermediate focal length is a value half that of the difference between the first focal length and the second focal length. Preferably, in the first projection mode, the first image projected by the first projection unit and the second image projected by the second projection unit are adjacent to each other. Preferably, an image synthesized by the first image and the second image is projected. Preferably, the switching control means can control the projection angles of the first projection means and the second projection means, respectively.

  The image projection method according to the present invention includes a first projection unit capable of projecting an image by the first projection optical system, a second projection unit capable of projecting an image by the second projection optical system, and a vehicle state And a vehicle state detection means for detecting the first projection distance to the first projection means and the second projection means in the first projection mode when the vehicle is stationary. When the vehicle is in a running state, the first projection unit projects an image with the first focal length and the second projection unit projects the second focal length when the vehicle is in a running state. And when switching from the second projection mode to the first projection mode, the first focal length of the first projection means is changed to an intermediate focal length, and the second projection means second Changing the focal length of the lens to the intermediate focal length. And a step, the focal length of the intermediate is greater than the first focal length, and is smaller than the second focal length.

  Preferably, the image projection method further changes the intermediate focal length of the first projection means to the first focal length, and changes the intermediate focal length of the second projection means to the first focal length. Includes steps. Preferably, when the image projection method further switches from the first projection mode to the second projection mode, the first focal length of the first projection means is changed to an intermediate focal length, and the second projection means Changing the first focal length to an intermediate focal length. Preferably, the image projecting method further includes the step of changing the intermediate focal length of the first projection means to the first focal length and changing the intermediate focal length of the second projection means to the second focal length. including.

  An image projection program according to the present invention includes a first projection unit capable of projecting an image by a first projection optical system, a second projection unit capable of projecting an image by a second projection optical system, and a vehicle state When the vehicle is in a stopped state, the first projection unit and the second projection unit perform the first projection on the first projection unit and the second projection unit when the vehicle is stationary. When the image is projected at the focal length and the vehicle is in a running state, the second projection mode causes the first projection means to project the image at the first focal length, and the second projection means causes the second focal length to be projected. The step of projecting an image at the time of switching the second projection mode to the first projection mode, the first focal length of the first projection means is changed to an intermediate focal length, and the second projection means Set the second focal length to the intermediate focal length And a step of reduction, the focal length of the intermediate is greater than the first focal length, and is smaller than the second focal length. Preferably, the image projection program further changes the first focal length of the first projection means to an intermediate focal length when switching from the first projection mode to the second projection mode, and the second projection means Changing the first focal length to an intermediate focal length.

  According to the present invention, when the first projection mode and the second projection mode are switched according to the vehicle state, the focal lengths of the first projection unit and the second projection unit are temporarily changed to an intermediate focal length. Since the transition to the initial projection mode is made later, even if the switching cycle between the first projection mode and the second projection mode is shortened, the change in the viewing distance of the virtual image due to the change in the focal length is reduced. As a result, the visibility is improved for the driver.

It is a figure which shows the structure of the image projection apparatus which concerns on 1st Example of this invention. It is a figure which shows the structural example of the 1st and 2nd projection part of a present Example. It is a figure which shows the example of an image projection by the 1st and 2nd projection part. It is a figure which shows the functional structural example of the image projection program which concerns on 1st Example of this invention. It is the figure which showed the relationship between the vehicle state, the determination element, and projection mode which concern on a 1st Example. It is a figure which illustrates the 1st projection mode. It is a figure which illustrates switching to the 1st projection mode. It is a figure which illustrates switching to the 2nd projection mode. It is a figure which shows the movement of a virtual image when the focal distance of a projection optical system is changed continuously. It is a flowchart which shows operation | movement of the image projection apparatus which concerns on a 1st Example. It is a figure which shows the switching flow from 1st projection mode to 2nd projection mode. It is a figure which shows the switching flow from 2nd projection mode to 1st projection mode. It is a figure which shows the example of a projection of the image of the 1st projection mode of a 1st Example, and a 2nd projection mode. It is the figure which showed the relationship between the vehicle state, determination element, and projection mode which concern on a 2nd Example. It is a flowchart which shows operation | movement of the image projection apparatus which concerns on a 2nd Example. It is a figure explaining the position of the virtual image at the time of the 1st projection mode of the 2nd example, the 2nd projection mode, and the 3rd projection mode. It is a figure which shows the example of a projection of the image at the time of 3rd projection mode. It is a flowchart which shows operation | movement of the image projection apparatus which concerns on the modification of a 2nd Example. It is a display example of conventional HUD. It is a display example of conventional HUD.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. An image projection apparatus according to an embodiment of the present invention includes a projection system represented by HUD. In a preferred embodiment, the image projection device projects an image on a windshield of a vehicle or a screen thereof, and can show a virtual image superimposed on the real space to the driver. The projected image is preferably information useful for the driver, for example, driving support information.

  FIG. 1 is a diagram showing a configuration of an image projection apparatus according to a first embodiment of the present invention. The image projection apparatus 10 according to the present embodiment includes a first projection unit 100 having a first projection optical system, a second projection unit 110 having a second projection optical system, a first projection unit 100, and a second projection unit 100. The image generation part 120 which produces | generates the image projected by the projection part 110 of this, the memory | storage part 130, the vehicle state detection part 140 which detects the state of a vehicle, the navigation part 150, and the control part 160 are comprised.

  The first projection unit 100 includes a light modulation unit that modulates light from the light source based on the image data generated by the image generation unit 120, and a first projection optical system that projects the light modulated by the light modulation unit. It has. The first projection optical system includes, for example, an optical member such as a lens or a prism, and projects the light modulated by the light modulation unit onto a screen such as a windshield inside the vehicle. The focal length and / or projection direction of the first projection optical system can be varied by control from the control unit 160. The second projection unit 110 has substantially the same configuration as that of the first projection unit 100, but the second projection unit 110 has a focal length and a projection direction independent of the first projection unit 100. Variable.

  FIG. 2 shows a configuration example of the first projection unit. The first projection unit 100 includes a light source 101, an illumination optical system 102, a light modulation unit 103, a projection optical system 104, and an actuator 105. The light source 101 is composed of, for example, a semiconductor light emitting element such as a light emitting diode array. The illumination optical system 102 focuses the light from the light source 101 and provides the light modulation means 103 with light having a predetermined aspect ratio. The light modulation means 103 is composed of, for example, a liquid crystal device or a digital mirror device in which a plurality of variable mirrors are two-dimensionally arranged. The light modulation unit 103 spatially modulates the emitted light according to the image data from the image generation unit 120. The projection optical system 104 projects the modulated light onto the screen 106.

  The actuator 105 can adjust the focal length by moving the position of the lens or the prism included in the projection optical system 104 based on the control signal S <b> 1 from the control unit 160. In an aspect, the projection optical system 104 projects an image that is zoomed up or down by continuously changing the focal length. Further, the actuator 105 can adjust the projection direction of the projection optical system 104 based on the control signal S <b> 1 from the control unit 160. For example, by tilting the optical axis of the projection optical system 104, the projection direction, that is, the position of the image projected on the screen can be changed.

  FIG. 3 shows an example of an image projected by the image projection apparatus. For example, the image projection apparatus 10 is installed in a dashboard in a vehicle as shown in FIG. For example, the first projecting unit 100 projects the image 100A on the windshield with a short focal length f1, and at this time, the driver U, as shown in FIG. The virtual image 100A ′ is visually recognized. For example, the second projection unit 110 projects the image 110A with a long focal length f2, and at this time, the driver U visually recognizes the virtual image 110A 'at a distance L2 far from the vehicle.

  The image generation unit 120 generates the image data in order to provide the driver with information corresponding to the vehicle state. For example, in the running state, image data for providing information such as vehicle speed information, tachometer information, current time, fuel gauge, and the like is generated. Further, when the navigation unit 150 is operated, image data for providing information such as the distance to the destination, the estimated arrival time, the guidance route, and the next intersection guidance is generated. Furthermore, when the image projection apparatus 10 has a function of communicating with an external traffic information distribution server or a function of receiving information distributed from a roadside device or the like, the traffic jam from the traffic information distribution server Image data for presenting information and the like and signal information from the roadside device can be generated. Furthermore, when an obstacle detection system using an in-vehicle camera is installed, frame-like image data surrounding the vehicle existing in front of the host vehicle is generated and superimposed on the actual vehicle ahead. It may be. The image generation unit 120 generates image data for an image projected by the first projection unit 100 and the second projection unit 110 according to the projection mode of the image projection device 10 under the control of the control unit 160. .

  The storage unit 130 can store various data. For example, the image generation unit 120 can store necessary image data, or can store a program executed by the control unit 160. Further, map data used in the navigation unit 150 can be stored.

  The vehicle state detection unit 140 acquires information related to the state of the vehicle. For example, vehicle speed pulse information, gear position information, brake information, turn signal information, and the like. Further, when an in-vehicle camera is mounted, information regarding the vehicle state obtained from the imaging data may be acquired. The detection result of the vehicle state detection unit 140 is provided to the control unit 160 and is used to determine the projection mode of the image projection apparatus 10 as will be described later.

  The navigation unit 150 calculates the vehicle position using a GPS signal, a self-contained navigation sensor, etc., displays a road map around the calculated vehicle position on the liquid crystal display, searches for a route to the destination, Guide the search route. In addition, when guiding the searched route, guidance information such as going straight at an intersection, turning right, turning left, etc. is presented. Information presented by the navigation unit 150 is provided to the image generation unit 120 as necessary, and such information can also be projected by the first projection unit 100 or the second projection unit 110.

  The control unit 160 controls each unit of the image projection apparatus 10. In a preferred embodiment, the control unit 160 includes a microcontroller including a ROM, a RAM, and the like, and the ROM or the RAM can store a program for controlling each unit. In the present embodiment, the control unit 160 executes an image projection program 200 that controls the projections of the first and second projection units 100 and 110.

  FIG. 4 is a diagram illustrating a functional configuration example of the image projection program according to the first embodiment. The image projection program 200 includes a vehicle information acquisition unit 210, a vehicle state determination unit 220, a projection mode determination unit 230, a switching control unit 240, a first actuator control unit 250, and a second actuator control unit 260.

  The vehicle information acquisition unit 210 acquires information about the vehicle detected by the vehicle state detection unit 140. For example, speed information, gear position information, turn signal information, brake information, and the like are acquired via an in-vehicle bus. The vehicle state determination unit 220 determines the vehicle state based on the information acquired by the vehicle information acquisition unit 210. In the first embodiment, it is determined whether the vehicle is stopped or traveling. For this determination, for example, speed information or gear position information is used. FIG. 5 shows an example of the relationship between the vehicle state, the determination criterion for determining this, and the projection mode. The vehicle state determination unit 220 determines that the vehicle is stopped when the gear position is the drive gear and the vehicle speed is less than 20 km / h. Further, when the gear position is the drive gear and the vehicle speed is 20 km / h or more, it is determined that the vehicle is running. The determination criterion of FIG. 5 is an example, and for example, determination may be made using a captured image or brake information from an imaging camera (not shown). Furthermore, when the gear position is parking, it may be determined that the vehicle is stopped.

  The determination result of the vehicle state determination unit 220 is provided to the projection mode determination unit 230. The projection mode determination unit 230 determines the first projection mode or the second projection mode based on the determination result of the vehicle state determination unit 220. As shown in FIG. 5, the projection mode determination unit 230 determines the first projection mode when the vehicle is determined to be in a stopped state and the second projection mode when it is determined as a traveling state.

  The first projection mode is a mode in which the first projection unit 100 and the second projection unit 110 each project an image at the same focal length, and the second projection mode is the first projection unit 100 and the first projection mode. In this mode, the two projection units 110 project images at different focal lengths. Preferably, in the first projection mode, the first and second projection units 100 and 110 each project an image with a short focal length f1, and in the second projection mode, the first projection unit 100 has a short focal length. An image is projected at f1, and the second projection unit 110 projects an image at a long focal length f2. FIG. 6A is an example of the first projection mode. The first projection unit 100 projects the image 100A at the first focal length f1, and the second projection unit 110 projects the image 110A at the first focal length f1. In this example, the images 100A and 110A are projected so as to be adjacent to each other. FIG. 6B shows a virtual image when viewed from the side, and the driver U visually recognizes each of the virtual images 100A ′ and 110A ′ of the images 100A and 110A at a distance L1 near from the viewpoint o. To do.

  In the second projection mode, as shown in FIG. 3A, the first projection unit 100 projects the image 100A at the first focal length f1, and the second projection unit 110 projects the second focal length f2. Thus, the image 110A is projected. Then, as shown in FIG. 3B, the driver U visually recognizes the virtual image 100A 'at the near distance L1 and visually recognizes the virtual image 110A' at the distant distance L2.

  When the determination result of the vehicle state determination unit 220 is changed, the switching control unit 240 performs switching from the first projection mode to the second projection mode, or from the second projection mode to the first projection mode. When the switching control unit 240 switches from the first projection mode to the second projection mode, or from the second projection mode to the first projection mode, the first projection unit prevents the focal length from changing suddenly. The first focal length f1 of 100 is changed to an intermediate focal length fc, the first or second focal length f1 / f2 of the second projection unit 110 is changed to the same intermediate focal length fc, After the second projection units 100 and 110 project an image at an intermediate focal length fc for a certain period, the focal length is changed to the final first projection mode or the second projection mode.

  When switching the projection mode, the switching control unit 240 controls the actuator 105 of the first projection unit 100 via the first actuator control unit 250, varies the focal length of the projection optical system 104, and second The actuator 105 of the second projection unit 110 is controlled via the actuator control unit 260 to vary the focal length of the projection optical system 104. At this time, the projection angles of the first projection unit 100 and the second projection unit 110 can be varied as necessary.

  For example, when switching from the second projection mode (FIG. 3) to the first projection mode (FIG. 6), the first focal length f1 of the first projection unit 100 is changed to the intermediate focal length fc, and the first After the second focal length f2 of the second projection unit 110 is changed to the intermediate focal length fc and the first and second projection units 100 and 110 coincide with the intermediate focal length fc, the first and second The intermediate focal length fc between the projection units 100 and 110 is changed to the first focal length f1.

  FIG. 7 schematically shows a virtual image when switching from the second projection mode to the first projection mode. As shown in FIG. 7A, when the first focal length f1 of the first projection unit 100 is changed to the intermediate focal length fc, the position of the virtual image 100A ′ is changed from the distance L1 to Lc. Move away. On the other hand, when the second focal length f2 of the second projection unit 110 is changed to the intermediate focal length fc, the position of the virtual image 110A ′ moves from the distance L2 toward Lc. The driver U visually recognizes two virtual images 100A 'and 110A' at a position at a distance Lc from the viewpoint o. Preferably, the intermediate focal length fc is fc = (f1 + f2) / 2, and at this time, Lc = (Ln + Lf) / 2. In this case, each actuator 105 of the first and second projection units 100 and 110 changes the focal length of the projection optical system by the same distance. For convenience, when the two virtual images 100A 'and 110A' are at a distance Lc, this position may be referred to as a welcome position. Next, as shown in FIG. 7B, the intermediate focal length fc between the first and second projection units 100 and 110 is changed to the first focal length f1, and the driver U moves from the viewpoint o. The virtual image 100A ′ and the virtual image 110 ′ are visually recognized at the position of L1.

  In one aspect, when the virtual images 100 </ b> A ′ and 110 </ b> A ′ are at the meeting position, the switching control unit 240 may reconfirm the determination result of the vehicle state determination unit 230. That is, when the virtual image is at the meeting position, if the determination result of the vehicle state determination unit 230 is not changed, the process proceeds to the first projection mode, but the determination result of the vehicle state determination unit 230 is changed. In this case (in this case, the determination result is changed to the running state), the second projection mode may be returned.

  On the other hand, when switching from the first projection mode to the second projection mode, as shown in FIG. 8A, the first focal length f1 of the first and second projection units 100 and 110 is set. The focal length is changed to an intermediate focal length fc, and the two virtual images 100A ′ and 110A ′ are moved to the welcome position. Next, as shown in FIG. 8B, the intermediate focal length fc of the first projection unit 100 is changed to the first focal length f1, the virtual image 100A ′ is moved to the position of the distance L1, and the first The intermediate focal length fc of the two projection units 110 is changed to the second focal length f2, and the virtual image 110A ′ is moved to the position of the distance L2. Also in this case, when in the meeting position, the switching control unit 240 may reconfirm the determination result of the vehicle state determination unit 230 and shift to the second projection mode based on the result.

  Note that the focal lengths of the first and second projection units 100 and 110 may be changed stepwise or continuously via the first actuator control unit 250 and the second actuator control unit 260. FIG. 9A shows an example of image projection when the second focal length f2 of the second projection unit 110 changes to an intermediate focal length fc. For example, the image 110A is projected at the first focal length at time t1, the image 110A is projected at a focal length greater than the first focal length at time t2, and the intermediate focal length at time t3. The image 110A is projected at fc. At this time, as shown in FIG. 9B, at time t1, t2, and t3, the virtual image 110A 'is visually recognized by the driver U so as to gradually move far away.

  Next, the operation of the image projection apparatus according to the first embodiment will be described with reference to the flow of FIG. 10A. The image projection program 200 starts to be executed, for example, when the vehicle ACC mode is turned on, when a specific application is activated, or when activation is instructed by a user input.

  When the image projection program 200 is activated, the vehicle information acquisition unit 210 acquires the vehicle state information detected by the vehicle state detection unit 140 (S100). Next, the vehicle state determination unit 220 determines whether the vehicle is in a stopped state or a traveling state based on the acquired vehicle state information, for example, according to a determination criterion as shown in FIG. 5 (S102). Based on the determination result, the projection mode determination unit 230 determines the first projection mode if the vehicle is in the stopped state (S104), and determines the second projection mode if the vehicle is in the traveling state (S106). The switching control unit 240 monitors the determination result of the vehicle state determination unit 220 and determines whether or not the mode is switched (S108). If there is no change in the determination of the stop state or the travel state, the current projection mode is maintained as it is (S110), and the projection mode is switched when the determination is changed from the stop state to the travel state or from the travel state to the stop state. Control is executed (S112).

  FIG. 10B is a flow when switching from the first projection mode to the second projection mode. When the determination result changes from the stopped state to the traveling state, switching from the first projection mode to the second projection mode is started (S120). The switching control unit 240 changes the focal length of the projection optical system 104 of the first projection unit 100 from the first focal length f1 to the intermediate focal length fc via the first actuator control unit 250, and the second actuator The focal length of the projection optical system 104 of the second projection unit 110 is changed from the first focal length f1 to the intermediate focal length fc via the control unit 260 (S122). This situation is shown in FIG.

  When the two virtual images 100A ′ and 110A ′ are displayed at the meeting position for a certain period, it is preferable that the switching control unit 240 reconfirms whether or not the determination result of the running state is continued (S124). When the traveling state is maintained, the mode is shifted to the second projection mode. That is, the switching control unit 240 changes the focal length of the projection optical system 104 of the first projection unit 100 via the first actuator control unit 250 from the intermediate focal length fc to the first focal length f1. The focal length of the projection optical system 104 of the second projection unit 110 is changed from the intermediate focal length fc to the second focal length f2 via the two actuator control unit 260 (S126). This situation is shown in FIG.

  On the other hand, when the determination result is changed to the stop state in the state where the vehicle is in the meeting position, the switching control unit 240 does not shift to the second projection mode but returns to the first projection mode. The focal length of the projection optical system 104 of the first projection unit 100 is changed from the intermediate focal length fc to the first focal length f1 via the unit 250, and the second projection is performed via the second actuator control unit 260. The focal length of the projection optical system 104 of the unit 110 is changed from the intermediate focal length fc to the first focal length f1 (S128).

  FIG. 10C is a flow when switching from the second projection mode to the first projection mode. When the determination result changes from the traveling state to the stopped state, switching from the second projection mode to the first projection mode is started (S130). The switching control unit 240 changes the focal length of the projection optical system 104 of the first projection unit 100 from the first focal length f1 to the intermediate focal length fc via the first actuator control unit 250, and the second actuator The focal length of the projection optical system 104 of the second projection unit 110 is changed from the second focal length f2 to the intermediate focal length fc via the control unit 260 (S132).

  When the two virtual images 100A 'and 110A' are displayed at the meeting position for a certain period, preferably, the switching control unit 240 reconfirms whether or not the stop state determination result is continued (S134). When the stop state is maintained, the first projection mode is entered. That is, the switching control unit 240 changes the focal length of the projection optical system 104 of the first projection unit 100 via the first actuator control unit 250 from the intermediate focal length fc to the first focal length f1. The focal length of the projection optical system 104 of the second projection unit 110 is changed from the intermediate focal length fc to the first focal length f1 via the two actuator control unit 260 (S136).

  On the other hand, when the determination result is changed to the running state in the state where it is in the meeting position, the switching control unit 240 returns to the second projection mode, and therefore the first projection unit via the first actuator control unit 250. The focal length of the projection optical system 104 of the second projection unit 110 is changed via the second actuator control unit 260 by changing the focal length of the projection optical system 104 of 100 from the intermediate focal length fc to the first focal length f1. Is changed from the intermediate focal length fc to the second focal length f2 (S138).

  The image projected in the first projection mode and the second projection mode is arbitrary. For example, in the second projection mode, as shown in FIG. A direction image 110A is projected, and in the first projection mode, an image different from that in the second projection mode can be displayed. For example, as shown in FIG. 11B, two images 100A and 100B are displayed. May be combined into a single image representing the speedometer and the direction of travel. In this way, a large image can be projected using one large projection screen.

  As described above, according to the first embodiment, when the first projection mode or the second projection mode is switched according to the stop state or the traveling state, a virtual image is displayed at an intermediate position between the far and near positions for the driver. Since the virtual image is moved far or near after the display, the virtual image is displayed even in a situation where the cycle between the running state and the stopped state is repeated in a short time while traveling on a road such as a traffic jam. The change in position can be reduced and the visibility of the driver can be improved. Furthermore, in the first projection mode, it is possible to present information on a larger image to the driver U by displaying one image by combining two virtual images.

  Next, a second embodiment of the present invention will be described. In the first embodiment, the image projection apparatus has two projection modes, a first projection mode and a second projection mode, as shown in FIG. 5, but in the second embodiment, a third projection is further provided. Has a mode. The third projection mode is a projection mode when traveling at high speed on a road such as a toll road or a highway.

  In FIG. 12, the relationship between the vehicle state by the 2nd Example, its determination element, and projection mode is shown. In the second embodiment, the vehicle state newly includes a high-speed traveling state. The determination as to whether or not the vehicle is traveling at high speed can be made using gear position information, speed information, map data of the navigation unit 150, and the like. For example, when the gear position is in the drive gear and the speed is 20 km / h or more and less than 80 km / h, it is determined as a running state, and when the gear position is the drive gear and the speed is 80 km / h or more, the speed is high. Running state and speed. Whether the vehicle is in a traveling state or a high-speed traveling state may refer to a road type or a road attribute included in link data of a road on which the vehicle is traveling. However, as an exception, even if the road on which the vehicle is traveling is a general road, if the traffic volume is low and the distance to the next signal is a certain distance or more, it is determined that the vehicle is traveling at high speed. You may do it. The traffic volume can be determined by referring to an image taken by an in-vehicle camera, information from an external road traffic information distribution server, information from a roadside device, or the like. Note that the criterion shown in FIG. 12 is an example.

  When the vehicle state determination unit 220 determines that the vehicle is traveling at a high speed, the projection mode determination unit 230 determines the third projection mode. In the third projection mode, the projection optical system of the first projection unit 100 is set to the third focal length, and the projection optical system of the second projection unit 110 is also set to the third focal length. The third focal length is larger than the second focal length in the second projection mode. Therefore, the virtual image in the third projection mode is visually recognized farther by the driver U.

  FIG. 13 is a flowchart illustrating the operation of the image projection apparatus according to the second embodiment. First, the vehicle information acquisition unit 210 acquires vehicle information from the vehicle state detection unit 140, the navigation unit 150, the imaging camera, or the like (S200). The vehicle state determination unit 220 determines the vehicle state based on the acquired vehicle information (S202). In the second embodiment, there are at least three stop states, a traveling state, and a high-speed traveling state (FIG. 12), and any one of the states is determined. When the vehicle state is determined by the vehicle state determination unit 220, the projection mode determination unit 230 is in a projection mode corresponding to the determined vehicle state, that is, in the first projection mode (S204) if the vehicle is stopped, in the traveling state. If there is, the second projection mode (S206) is determined, and if it is in the high speed traveling state, the third projection mode is determined (S208).

  FIG. 14A illustrates the position of the virtual image when switching from the second projection mode to the third projection mode. When in the second projection mode, the first projection unit 100 projects the image 100A at the first focal length, the second projection unit 110 projects the image 110A at the second focal length, and hence a virtual image. 100A ′ is located at the distance L1, and the virtual image 110A ′ is located at the distance L2. When switching to the third projection mode, the first focal length f1 of the first projection unit 100 is changed to the third focal length f3, and the second focal length f2 of the second projection unit 110 is the third. The focal length is changed. As a result, the driver U visually recognizes the virtual image 100A′110A ′ at a distance L3 far from the viewpoint o.

  In the third projection mode, the projection mode is not limited to the two virtual images 100A ′ and 110A ′ being adjacent to each other as shown in FIG. 15A. For example, as shown in FIG. And 110A ′ may be separated. In this case, the projection direction of the first or second projection unit is also variable. Further, the virtual images 100A ′ and 110A ′ may be projected to a position deviating from the driver's U line-of-sight direction. In this case, the first actuator control unit 250 changes the projection angle in a predetermined direction, or when a gaze detection camera that detects the driver's gaze is mounted, a virtual image is detected in the detected gaze direction. The projection angle is adjusted so that 100A ′ or 110A ′ does not overlap.

  Also in the second embodiment, as in the first embodiment, when the mode is switched, the image is once projected at the intermediate focal length fc and then changed to the final projection mode focal length. You may make it make it. FIG. 16 shows a flowchart for switching. Here, steps S200 to S208 are the same as those in FIG. The switching control unit 240 determines whether or not the projection mode is switched based on the determination result of the vehicle state determination unit 220 (S210), and changes the projection mode between the first projection mode and the second projection mode. The same control as in the first embodiment is performed.

  When changing from the second projection mode to the third projection mode, or from the third projection mode to the second projection mode, the first focal length f1 of the first projection unit 100 is the third focal point. Since the distance f3 is largely changed, the intermediate focal length fc of the first irradiation unit 100 may be set to the second focal length f2. This is shown in FIG. That is, when the second projection mode is switched to the third projection mode, the first focal length f1 of the first projection unit 100 is changed to an intermediate focal length fc (fc = second focal length f2). Once, it is made to coincide with the second focal length f2 of the second projection unit 110. Next, the second focal length of the first and second projection units 100 and 110 is changed to the third focal length.

  In the second embodiment, when it is determined that the vehicle is traveling at high speed, the virtual images 100A ′ and 110A ′ are further displayed in the far distance by the third projection mode. When the line of sight is directed far away, an image can be seen in the direction of the line of sight, and the visibility is further improved. Further, when switching from the second projection mode to the third projection mode, the first focal length f1 of the first projection unit 100 is made to coincide with the second focal length f2 of the second projection unit 110, and then the third Therefore, the virtual image can be visually recognized without a sense of incongruity for the driver.

  In the said Example, although the structure provided with the 1st projection part 100 and the 2nd projection part was illustrated, this may be a structure provided with two separate projection parts physically, and is a common part It may be a configuration in which two projection units are functionally realized by sharing. Further, in the above embodiment, when the projection mode is switched according to the stop state or the traveling state, the virtual image is moved far or near after the virtual image is displayed at the intermediate position. The intermediate position in the above does not mean a strict intermediate point, and may be any position as long as it is located between the far and near points.

  The preferred embodiment of the present invention has been described in detail above. However, the present invention is not limited to the specific embodiment, and various modifications and variations are possible within the scope of the gist of the invention described in the claims. It can be changed.

1A: HUD 1B: HUD
DESCRIPTION OF SYMBOLS 10: Image projector 100: 1st projection part 100A ': Virtual image 101: Light source 102: Illumination optical system 103: Light modulation means 104: Projection optical system 105: Actuator 106: Screen 110: 2nd projection part 110A': Virtual image 120: Image generation unit 130: Storage unit 140: Vehicle state detection unit 150: Navigation unit 160: Control unit 200: Image projection program 210: Vehicle information acquisition unit 220: Vehicle state determination unit 230: Projection mode determination unit 240: Switching Control unit 250: first actuator control unit 260: second actuator control unit U: driver

Claims (20)

First projection means capable of projecting an image by the first projection optical system;
A second projection means capable of projecting an image by the second projection optical system;
A first projection mode in which the first projection means and the second projection means project an image at a first focal length;
A second projection mode in which the first projection means projects an image at a first focal length, and the second projection means projects an image at a second focal length;
Vehicle state detection means for detecting the state of the vehicle;
Switching control means for controlling the first and second projection means based on the detection result of the vehicle state detection means and controlling the switching of the projection mode;
The switching control unit switches the first focal length of the first projection unit between the first focal length and the second focal length when switching from the second projection mode to the first projection mode. The focal length is changed, and the second focal length of the second projection means is changed to the intermediate focal length, and the intermediate focal length is larger than the first focal length and larger than the second focal length. The image projection device is also small. The switching control unit further changes the intermediate focal length of the first projection unit to the first focal length, and changes the intermediate focal length of the second projection unit to the first focal length. The image projection apparatus according to claim 1. 3. The image according to claim 1, wherein when switching from the second projection mode to the first projection mode, the first and second projection means project an image at the intermediate focal length for a certain period. 4. Projection device. Said switching control means, when switching from the first projection mode to the second projection mode, the first focal length is changed to the focal length of the intermediate, and the second projection means in the first projecting means The image projection apparatus according to claim 1, wherein a focal length of 1 is changed to the intermediate focal length. The switching control unit further changes the intermediate focal length of the first projection unit to a first focal length, and changes the intermediate focal length of the second projection unit to a second focal length. Item 5. The image projection device according to Item 4 . 6. The image according to claim 4, wherein when switching from the first projection mode to the second projection mode, the first and second projection means project an image at the intermediate focal length for a certain period of time. Projection device. The image projection apparatus further includes vehicle state determination means for determining whether the vehicle is in a stopped state or a traveling state based on a detection result of the vehicle state detection means, and the switching control means is configured to determine whether the vehicle is in a stopped state. The image projection device according to any one of claims 1 to 6, wherein a projection mode is selected, and a second projection mode is selected when it is determined that the vehicle is in a running state. The switching control unit reconfirms the determination result of the vehicle state determination unit when the first projection unit and the second projection unit are at the intermediate focal length, and when the determination result is changed, The image projection apparatus according to claim 7, wherein the first and second projection means are shifted to the original projection mode. The vehicle state detection means includes vehicle speed information, and the vehicle state determination means determines that the vehicle is stopped when the vehicle speed is less than a threshold, and travels when the vehicle speed is greater than or equal to the threshold. The image projection apparatus according to claim 7, wherein the image projection apparatus is determined to be in a state. The switching control means continuously changes the first focal length of the first projection means to the intermediate focal length, and changes the first or second focal length of the second projection means to the intermediate focal length. The image projection apparatus according to claim 1, wherein the image projection apparatus is continuously changed to a distance. The image projection apparatus according to claim 1, wherein the intermediate focal length is a value that is a half of a difference between the first focal length and the second focal length. The first image projected by the first projection means and the second image projected by the second projection means are adjacent to each other in the first projection mode. The image projection apparatus described in 1. The image projection apparatus according to claim 12, wherein an image synthesized by the first image and the second image is projected. The image projection apparatus according to claim 1, wherein the switching control unit is capable of controlling projection angles of the first projection unit and the second projection unit. First projection means capable of projecting an image by the first projection optical system, second projection means capable of projecting an image by the second projection optical system, and vehicle state detection means for detecting the state of the vehicle An image projection method in an image projection apparatus comprising:
When the vehicle is stationary, the first projection mode causes the first projection means and the second projection means to project an image at the first focal length, and when the vehicle is in the running state, the second projection mode Causing the first projection means to project an image at a first focal length and causing the second projection means to project an image at a second focal length; and
When switching from the second projection mode to the first projection mode, the first focal length of the first projection means is changed to an intermediate focal length between the first focal length and the second focal length , And changing the second focal length of the second projection means to the intermediate focal length, wherein the intermediate focal length is larger than the first focal length and smaller than the second focal length. , Image projection method. The image projection method further includes the steps of: changing the intermediate focal length of the first projection means to the first focal length; and changing the intermediate focal length of the second projection means to the first focal length. The image projection method according to claim 15, further comprising: Image projection method further when switching from the first projection mode to the second projection mode, the first focal length is changed to the focal length of the intermediate, and the second projection means in the first projecting means 1 of focal length comprising varying the focal length of the intermediate image projection method of claim 15. The image projection method further includes the step of changing the intermediate focal length of the first projection means to the first focal length and changing the intermediate focal length of the second projection means to the second focal length. The image projection method according to claim 17. First projection means capable of projecting an image by the first projection optical system, second projection means capable of projecting an image by the second projection optical system, and vehicle state detection means for detecting the state of the vehicle An image projection program executed by an image projection apparatus having
When the vehicle is stationary, the first projection mode causes the first projection means and the second projection means to project an image at the first focal length, and when the vehicle is in the running state, the second projection mode Causing the first projection means to project an image at a first focal length and causing the second projection means to project an image at a second focal length; and
When switching from the second projection mode to the first projection mode, the first focal length of the first projection means is changed to an intermediate focal length between the first focal length and the second focal length , And changing the second focal length of the second projection means to the intermediate focal length, wherein the intermediate focal length is larger than the first focal length and smaller than the second focal length. , Image projection program. Image projection program further, when switching from the first projection mode to the second projection mode, the first focal length is changed to the focal length of the intermediate, and the second projection means in the first projecting means 1 of focal length comprising varying the focal length of the intermediate image projection program of claim 19.

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