JP2019008100A - Image display device, image display method, and image display program - Google Patents

Abstract

To reduce time required for a driver to visually recognize display contents of a virtual image at a predetermined display position after power supply of an HUD is turned on.SOLUTION: An image display device 100 according to the present invention comprises: a projection unit 120 that projects display light corresponding to an image visually recognized as a virtual image through a projection surface; a rotating reflection unit 140 that is provided rotatably and reflects the display light toward the projection surface; a driving unit 150 that rotates the rotating reflection unit 140 to change an angle to reflect the display light; and a control unit 110 that adjusts a display area of the image in the projection unit 120 according to the angle so that the virtual image is visually recognized at a predetermined position on the projection surface.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an image display device, an image display method, and an image display program.

  2. Description of the Related Art In recent years, a head up display (HUD) that provides information related to a vehicle and driving by projecting a virtual image through a windshield has been developed as a vehicle display device. In such a HUD, in a structure in which an image is projected using a concave mirror that is a reflecting mirror, sunlight is directly emitted under a specific condition that is a certain sunlight position at a concave mirror angle in a state in which a virtual image is actually displayed. May be incident. As a result, a display device such as a TFT (Thin Film Transistor) is exposed to high heat, which may lead to failure such as component destruction. However, since the situation changes each time the car is moving, the specific sunlight does not continue for a long time, and it is difficult to reach this problem. However, this problem may be caused by being exposed to the same conditions for a long time, such as while parked. For this reason, the HUD drives the concave mirror to a predetermined sunlight retraction angle when the power is OFF, thereby avoiding an increase in the temperature of the TFT.

  Here, Patent Document 1 discloses a technique related to a head-up display device that produces display contents in a time required for the reflecting mirror to rotate from a sunlight retraction angle to a normal angle.

Japanese Patent Laid-Open No. 2006-88124

  However, when the HUD is activated, there is a problem in that it takes a long time for the driver to visually recognize the display content of the virtual image projected from the HUD onto the windshield at a predetermined display position. In a normal HUD, after turning on the power, the concave mirror is rotated from the sunlight retraction angle to a predetermined angle, and then the original image display is started. Therefore, much processing time is required until the concave mirror is rotated to a predetermined angle.

  Moreover, in patent document 1 mentioned above, a transient display is performed until a reflecting mirror reaches a predetermined angle. Here, the transient display is not the original display content, and the position where the virtual image is visually recognized is not the final display position. Therefore, even in Patent Document 1, there is a problem that it takes a long time for the driver to visually recognize the display content of the virtual image projected from the HUD at a predetermined display position.

  The present invention has been made in view of the above-described problems, and is an image display device for shortening the time required until the display content of a virtual image can be visually recognized at a predetermined display position after the HUD is turned on. An object is to provide an image display method and an image display program.

  According to a first aspect of the present invention, a projection unit that projects display light corresponding to an image that is visually recognized as a virtual image via a projection surface, and a rotatable projection unit that reflects the display light toward the projection surface. A turning reflection part to be turned, a drive part to turn the turning reflection part to reflect the display light, and the virtual image to be visually recognized at a predetermined display position on the projection plane. An image display apparatus comprising: a control unit that adjusts a display area of the image in a projection unit according to the angle.

  According to a second aspect of the present invention, a projection unit that projects display light corresponding to an image that is visually recognized as a virtual image via a projection surface, and a rotatable projection unit that reflects the display light toward the projection surface. An image display method in an image display device comprising: a turning reflection unit that rotates; and a driving unit that rotates the turning reflection unit, wherein an angle at which the display light is reflected is changed with respect to the driving unit. As described above, the step of instructing the rotation reflection unit to rotate, and the display area of the image in the projection unit at the angle so that the virtual image is visually recognized at a predetermined display position on the projection surface. And an image display method including the step of adjusting accordingly.

  According to a third aspect of the present invention, a projection unit that projects display light corresponding to an image that is visually recognized as a virtual image via the projection surface, and a projection unit that is rotatable and reflects the display light toward the projection surface. A rotation reflection unit that rotates the rotation reflection unit, and a drive unit that rotates the rotation reflection unit. The rotation reflection unit is configured to change an angle of reflecting the display light with respect to the drive unit. And a step of adjusting a display area of the image according to the angle so that the virtual image is visually recognized at a predetermined display position on the projection plane. An image display program to be executed is provided.

  According to the present invention, it is possible to provide an image display device, an image display method, and an image display program for shortening the time required until the display content of a virtual image can be visually recognized at a predetermined display position after the HUD is turned on. it can.

It is a figure which shows typically the motor vehicle carrying the head up display apparatus concerning this Embodiment 1. FIG. It is a side view which shows typically the structure of the head-up display apparatus installed on the dashboard concerning this Embodiment 1. FIG. It is a side view which shows the structure of the projection part concerning this Embodiment 1. FIG. 1 is a block diagram illustrating a configuration of a head-up display device according to a first embodiment. It is a figure for demonstrating notionally the relationship between the position of the pixel on a display element, the angle of a rotation reflection part, and the display position of the virtual image visually recognized by projection surface shape. 6 is a flowchart for explaining a flow of image display processing by the head-up display device according to the first embodiment; It is a figure for demonstrating the relationship between the angle of the concave mirror concerning a related technique, the display area of a display element, and a virtual image. It is a figure for demonstrating the relationship between the angle of the concave mirror concerning this Embodiment 1, the display area of a display element, and a virtual image. It is a flowchart for demonstrating the flow of the image display process by the head-up display apparatus concerning related technology.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description will be omitted as necessary for the sake of clarity.

  First, problems to be solved by the present invention will be described. FIG. 9 is a flowchart for explaining the flow of image display processing by the head-up display device (HUD) according to the related art. First, the HUD is powered on (S901). Next, the HUD starts rotating from the sunlight retraction angle to a predetermined angle with respect to the concave mirror. In other words, the HUD starts to move the concave mirror from the sunlight retracting position X to the user display setting position Z (S910). Thereafter, when the concave mirror moves to the user display setting position Z (YES in S931), the HUD performs image processing according to the user display setting position Z and then starts image display (S932). Then, the concave mirror completes the movement to the user display setting position Z (S940), and the HUD completes the activation process (S950). Therefore, the driver cannot visually recognize the virtual image through the windshield during the HUD activation time. That is, there is a problem in that the display start time, which is the time required for the driver to visually recognize the virtual image through the windshield after the HUD is turned on, is long.

  And also in patent document 1, the said problem generate | occur | produces as mentioned above. Furthermore, in patent document 1, when performing a transient display, there also exists a problem that a big distortion may generate | occur | produce in the virtual image visually recognized. Therefore, the visibility of the user is remarkably inferior.

  It is also conceivable to shorten the display start time by increasing the driving speed for rotating the reflecting mirror. However, in this case, since the drive noise becomes large, the quality of the display content of the virtual image cannot be maintained. Also, in this case, driving problems such as a step-out of a motor that rotates the reflecting mirror may occur.

  An embodiment for solving the above-described problem will be described below.

<Embodiment 1>
(overall structure)
Embodiments of the present invention will be described below with reference to the drawings. In the following description, the image display device according to the present embodiment is a head-up display device mounted on an automobile. Further, the description will be made assuming that the head-up display device is mounted on a dashboard of an automobile. The head-up display device may be attached to a vehicle other than an automobile or a vehicle other than a vehicle.

  FIG. 1 is a diagram schematically showing a configuration of a head-up display device 100 installed on a dashboard 10 of an automobile 1. In FIG. 1, the driver U is an observer. The head-up display device 100 emits display light LA that has been generated and adjusted so as to display a desired image. The head-up display device 100 is disposed in front of the steering wheel 12.

  The display light LA is emitted toward the windshield (front glass) 11. The windshield 11 transmits part of visible light and reflects part of it. Therefore, the windshield 11 reflects the display light LA in the direction of the driver U. The display light LA reflected by the windshield 11 enters the eyes of the driver U and forms an image on the retina. At the same time, external light LB from the outside also enters the windshield 11. The external light LB passes through the windshield 11 and enters the eyes of the driver U. Therefore, the external light LB from the outside world and the display light LA from the head-up display device 100 are overlaid (superimposed), and the driver U's field of view includes an actual scene of the outside world and an image generated by the head-up display device 100. Will be visible at the same time. The head-up display device 100 displays a virtual image in front of the windshield 11. Thereby, even if the driver | operator U is operating the steering wheel 12, an image can be visually recognized without dropping a line of sight. The windshield 11 is a projection plane according to the present embodiment.

  In the following description, the direction in which the head-up display device 100 is placed on the dashboard 10 of the automobile 1 will be described as a reference. That is, the direction of the automobile 1 is set as a reference direction. For example, the windshield 11 side will be described as the front, and the driver U side will be described as the rear. Similarly, the description will be made with the roof side of the automobile 1 as the upper side, the ground side as the lower side, and the lateral direction (left-right direction) of the automobile 1 as the side.

(Head-up display device 100)
The configuration of the head-up display device 100 will be described in detail with reference to FIG. FIG. 2 is a side view schematically showing the configuration of the head-up display device 100. The head-up display device 100 includes a control unit 110, a projection unit 120, a reflecting mirror 130, a concave mirror 140, a driving unit 150, and a storage unit 160.

  The projection unit 120 has a projector that projects the display light LA. Specifically, the projection unit 120 includes a light source that generates light, a light modulation element that modulates light generated by the light source according to a control signal, a projection lens that projects light, and the like. For example, a liquid crystal panel that is a light modulation element modulates light from a backlight light source. Alternatively, a scanning mirror such as a MEMS (Micro Electronics Mechanical System) mirror can be used as the light modulation element. In this case, the scanning mirror scans light from a light source such as a laser diode or an LED (Light Emitting Diode) according to the control signal.

  The projection unit 120 projects the display light LA according to the control signal. Specifically, the projection unit 120 generates display light LA corresponding to the projection image and emits it forward. Reflecting mirrors 130 are disposed above and behind the projection unit 120. A concave mirror 140 is disposed on the upper front side of the reflecting mirror 130. Accordingly, the display light LA from the projection unit 120 enters the reflecting mirror 130. Then, the display light LA reflected by the reflecting mirror 130 enters the concave mirror 140.

  The concave mirror 140 reflects the display light LA from the projection unit 120 upward. Since the display light LA reflected by the concave mirror 140 travels while spreading, the displayed image is enlarged. The windshield 11 is disposed above the concave mirror 140. Accordingly, the display light LA reflected by the concave mirror 140 enters the windshield 11. In other words, the concave mirror 140 reflects the display light LA toward the windshield 11. The concave mirror 140 constitutes an optical system that guides the display light LA to the windshield 11. The optical system that guides the display light LA to the windshield 11 may include other optical components such as a lens and a reflecting mirror in addition to the concave mirror 140.

  Further, the concave mirror 140 is provided so that the reflection surface thereof can be rotated between the upper side and the rear side by the driving unit 150. Therefore, the concave mirror 140 can also be referred to as a rotating reflection unit. In addition, the driving unit 150 rotates the concave mirror 140 to change the angle at which the concave mirror 140 reflects the display light LA. The drive unit 150 is, for example, a stepping motor that operates according to a control signal from the control unit 110.

  The windshield 11 reflects a part of the incident display light LA to display the virtual image V. Therefore, as described above, the display light reflected by the windshield 11 enters the eyes of the driver U.

  The control unit 110 is an information processing device having a processor, a memory, and the like, and comprehensively controls the entire head-up display device 100. The control unit 110 generates a control signal based on display data input from the outside or the storage unit 160. Then, the control unit 110 outputs a control signal to the projection unit 120.

  The storage unit 160 is a volatile or nonvolatile storage device. The storage unit 160 stores, as display data, a corrected image obtained by correcting distortion of an image to be displayed and a control program.

(Projection unit 120)
Next, the configuration of the projection unit 120 will be described with reference to FIG. FIG. 3 is a diagram illustrating the configuration of the projection unit 120. The projection unit 120 includes a light source 121, a light tunnel 122, a Fresnel lens 123, a diffusion plate 124, and a display element 125.

  The light source 121 is an LED (Light Emitting Diode) or the like and emits light. The light enters the light tunnel 122 from the light source 121. The light tunnel 122 is a light guide member having a reflective surface inside, and spreads light from the light source 121 so that light is incident on almost the entire surface of the display element 125. That is, the light tunnel 122 converts light from the LED into planar light. The light that has passed through the light tunnel 122 enters the Fresnel lens 123.

  The Fresnel lens 123 refracts the light emitted from the light tunnel 122. The light that has passed through the Fresnel lens 123 enters the diffusion plate 124. The diffusion plate 124 diffuses light. The light that has passed through the diffusion plate 124 enters the display element 125.

  The display element 125 is a light modulation element such as a liquid crystal panel. The display element 125 is, for example, a TFT or a transmissive liquid crystal panel, and includes a plurality of pixels arranged in a matrix. Each pixel is controlled according to a control signal. Therefore, the display element 125 modulates light according to the control signal from the control unit 110. Specifically, the display element 125 controls the transmittance for each pixel in accordance with a control signal including gradation data. The light that has passed through the display element 125 becomes display light LA corresponding to the control signal. Thereby, the projection unit 120 can generate the display light LA for forming a desired image.

  The projection unit 120 is not limited to the one using a transmissive liquid crystal panel, and may use another light modulation element such as a reflective liquid crystal panel or a MEMS mirror. Further, the projection unit 120 may include other optical components such as a projection lens.

  Here, the display element 125 uses a part of the plurality of pixels as a display area corresponding to the entire display target image. Then, the display element 125 changes the range of the display area among the plurality of pixels according to a control signal from the control unit 110.

(Control configuration)
Next, the control configuration of the head-up display device 100 will be described with reference to FIG. FIG. 4 is a block diagram illustrating a control configuration of the head-up display device 100. The control unit 110 includes a drive control unit 111, a CPU (Central Processing Unit) 112, a projection control unit 113, and a display control unit 114.

  In the head-up display device 100, the CPU 112 reads and executes a control program (not shown) stored in the storage unit 160. Thereby, the CPU 112 controls the drive control unit 111, the projection control unit 113, and the display control unit 114 according to the present embodiment. Therefore, the control unit 110 may be realized by a general-purpose computer device.

  Here, in a state in which the power of the head-up display device 100 is turned off, the concave mirror 140 is at an angle that is a sunlight retracting position. That is, in this state, it is assumed that sunlight does not enter the concave mirror 140 or at least sunlight does not enter the display element 125 even if it enters. Then, the CPU 112 notifies the drive control unit 111 of a position control signal of the drive unit 150 from when the power is turned on to the head-up display device 100.

  The drive control unit 111 outputs the position control signal notified from the CPU 112 to the drive unit 150. The drive unit 150 rotates the concave mirror 140 according to the position control signal from the drive control unit 111. Here, it is assumed that the user has previously set a user display setting position indicating the angle of the concave mirror 140 during the normal operation of the head-up display device 100. Therefore, the CPU 112 instructs the drive control unit 111 to rotate the concave mirror 140 from the sunlight retracting position to the user display setting position at the time of activation.

  In addition, the CPU 112 instructs the projection control unit 113 to adjust the display area of the display target image and instructs the display control unit 114 according to a position control signal that instructs the drive control unit 111. Instructs distortion correction of the display target image. That is, the projection control unit 113 controls the light source 121 in accordance with an instruction from the CPU 112. Further, the display control unit 114 controls the display element 125 in accordance with an instruction from the CPU 112. At that time, the projection control unit 113 and the display control unit 114 generate a control signal based on the display target image in accordance with the position control signal instructed from the CPU 112. The projection control unit 113 outputs the generated control signal to the light source 121 of the projection unit 120. In addition, the display control unit 114 outputs the generated control signal to the display element 125 of the projection unit 120.

  As described above, the projection unit 120 emits the display light LA modulated according to the control signal. Specifically, the light source 121 generates light having luminance according to a control signal from the projection control unit 113. The display element 125 modulates light from the light source 121. Here, the display element 125 uses a part of all the pixels as a display area of the display target image in accordance with a control signal from the display control unit 114. Thereby, the display light LA corresponding to the display target image is projected from the projection unit 120. The display light LA is projected onto the windshield 11 via the reflecting mirror 130 and the concave mirror 140.

  Here, the processing of the display control unit 114 will be described in detail. The display control unit 114 adjusts the display area of the image in the projection unit 120 according to the angle of the concave mirror 140 so that the virtual image V is visually recognized at a predetermined display position on the windshield 11. Here, the display control unit 114 identifies the angle of the concave mirror 140 based on a control signal for rotating the concave mirror 140 with respect to the driving unit 150, that is, based on a pulse of the position control signal of the driving unit 150. Then, the display control unit 114 adjusts the display area of the display target image on the display element 125 according to the identified angle. Therefore, angle feedback from the drive unit 150 is unnecessary, and projection control can be performed quickly. Further, the “predetermined display position” indicates a position equivalent to the virtual image V that the driver U can visually recognize during the normal operation of the head-up display device 100. In other words, the “predetermined display position” is visually recognized as a virtual image V on the windshield 11 after the head-up display device 100 is activated and the concave mirror 140 has finished rotating from the sunlight retracting position to the user display setting position. Indicates that the position is equivalent to the position. Therefore, the driver U displays the display position equivalent to when the concave mirror 140 is rotated to the user display setting position immediately after the head-up display device 100 is started and before the concave mirror 140 reaches the angle of the user display setting position. Thus, the virtual image V can be visually recognized through the windshield 11. That is, the driver U can visually recognize the virtual image V at a normal position on the windshield 11 even when the concave mirror 140 is rotating.

  In addition, the display control unit 114 changes the pixels corresponding to the display target image according to the change in the angle of the concave mirror 140 so that the virtual image V is visually recognized at a predetermined display position on the windshield 11, thereby displaying the display region. Adjust.

  Here, the relationship between the position of the pixel on the display element 125, the angle of the concave mirror 140, and the display position of the virtual image visually recognized on the windshield 11 will be conceptually described with reference to FIG. First, it is assumed that the concave mirror 140 rotates from the sunlight retreat position X to the position Y1, and from the position Y1 to the user display setting position Z. When the concave mirror 140 is at the angle of the sunlight retracting position X, display light is not projected from the display element 125. Further, when the concave mirror 140 is at the angle of the user display setting position Z, the display light is projected from the pixel PZ of the display element 125 at a specific point of the display target image in both the related technique and the present embodiment. And In this case, the display light is reflected by the reflecting mirror 130 via the optical path L1Z, reflected by the concave mirror 140 at the user display setting position Z via the optical path L2Z, and reflected by the windshield 11 via the optical path L3Z. Then, it enters the eyes of the driver U via the optical path L4Z. Then, the driver U visually recognizes the specific point through the windshield 11 at the position PVZ. That is, the specific point of the display target image indicates that the concave mirror 140 is visually recognized as a virtual image at the position PVZ when the concave mirror 140 is at the angle of the user display setting position Z. In other words, the position PVZ can be said to be a predetermined display position of the virtual image during normal operation.

  In the related art, as described above, when the concave mirror 140 is at the angle of the position Y1, the display target image is not normally projected. Accordingly, a case will be described in which the display target image is projected when the concave mirror 140 is at the angle of the position Y1 in the related art. In this case, since the display area of the display target image is constant in the related art, display light is projected from the pixel PZ of the display element 125 at a specific point of the display target image. The display light is reflected by the reflecting mirror 130 via the optical path L1Z, and is reflected by the concave mirror 140 at the position Y1 via the optical path L2Z. Therefore, the display light is reflected by the windshield 11 via the optical path L3W, and enters the eyes of the driver U via the optical path L4W. Then, the driver U visually recognizes the specific point through the windshield 11 at the position PVW. That is, the specific point of the display target image is visually recognized as a virtual image at the position PVW in the related art when the concave mirror 140 is at the angle of the position Y1. Therefore, since it is visually recognized as a virtual image at a position PVW different from the position PVZ during normal operation, the visibility is reduced in the related art.

  In contrast, in the present embodiment, when the concave mirror 140 is at the angle of the position Y1, a specific point of the display target image is projected from the pixel PY1 of the display element 125 as display light. Then, the display light is reflected by the reflecting mirror 130 via the optical path L1Y1, and is reflected by the concave mirror 140 at the position Y1 via the optical path L2Y1. Therefore, as in the case of the angle of the user display setting position Z, the display light is reflected by the windshield 11 via the optical path L3Z and enters the eyes of the driver U via the optical path L4Z. Then, the driver U visually recognizes the specific point through the windshield 11 at the position PVZ. That is, the specific point of the display target image is visually recognized as a virtual image at the position PVZ even when the concave mirror 140 is at the angle of the position Y1 as in the case of the angle of the user display setting position Z. Therefore, in the present embodiment, when the concave mirror 140 is at the angle of the position Y1, the projection unit is configured so that the specific point of the display target image is visually recognized at the predetermined display position PVZ on the windshield 11. The image display area at 120, that is, the position of the pixel is changed from the pixel PZ to the pixel PY1. Thereby, in this Embodiment, the visibility of a virtual image is maintainable even when the concave mirror 140 is rotating compared with related technology.

Returning to FIG.
The display control unit 114 causes the projection unit 120 to project display light corresponding to a corrected image whose distortion has been corrected according to the angle of the concave mirror 140 so that the virtual image V is visually recognized in a predetermined shape on the windshield 11. Here, the “predetermined shape” indicates that the driver U has a shape equivalent to the virtual image V that can be visually recognized during the normal operation of the head-up display device 100. Since the windshield 11 is curved, when a display target image having the same shape is projected from the display element 125, the angle of the concave mirror 140 is different, so that the virtual image V visually recognized on the windshield 11 is distorted. Therefore, for example, by performing different distortion correction when the concave mirror 140 is at the angle of the user display setting position Z and at the angle of the position Y1, the virtual image V having the same shape can be visually recognized in any case. it can. That is, a correction in which distortion correction is performed on the display target image in the case of the angle of the position Y1, with the target being the shape of the virtual image V viewed from the display target image when the concave mirror 140 is at the angle of the user display setting position Z An image is projected from the display element 125.

  Specifically, the shape of the virtual image V when the display target image is projected on the windshield 11 at various angles of the concave mirror 140 is predicted in advance by simulation. Then, the distortion correction value in the vector calculation is changed so that the predicted shape of the virtual image V corresponding to each angle approaches the shape of the virtual image V in the case of the angle of the user display setting position Z. Then, a plurality of corrected images are generated by performing different distortion correction on the same display target image according to each angle of the concave mirror 140. Then, a plurality of corrected images 161, 162,... Generated in the storage unit 160 are stored in association with each angle of the concave mirror 140. Note that the corrected image 161 or the like may be a logo or startup screen as an example of a display target image, and distortion corrected for these. The display control unit 114 identifies the current angle of the concave mirror 140 based on the position control signal instructed from the CPU 112, and reads a correction image corresponding to the identified angle from the storage unit 160. Then, the projection control unit 113 causes the projection unit 120 to project display light corresponding to the read correction image. Instead of storing the corrected image in the storage unit 160, the display control unit 114 may perform distortion correction on the display target image in real time according to the angle. However, the processing can be speeded up by using a corrected image generated in advance.

  Alternatively, the display control unit 114 may acquire a corrected image from an external device (not shown). Here, the external device performs distortion correction according to the angle from the display target image to be displayed on the head-up display device 100, and outputs a corrected image after distortion correction to the head-up display device 100. For example, the external device is a car navigation device, another device connected via a CAN (Control Area Network), or the like. The external device may be an external terminal such as a smartphone or a tablet terminal.

(Processing flow)
FIG. 6 is a flowchart for explaining the flow of the image display process performed by the head-up display device according to the first embodiment. As a premise, the power of the head-up display device 100 is turned off, and the concave mirror 140 is in the sunlight retreat position X.

  Therefore, first, the head-up display device 100 is powered on (S101). Next, the head-up display device 100 starts to rotate the concave mirror 140 from the sunlight retracting position X to the user display setting position Z (S110). Specifically, the control unit 110 outputs a position control signal to the drive unit 150. Then, the driving unit 150 rotates the concave mirror 140 according to the position control signal from the control unit 110.

  Subsequently, when the concave mirror 140 moves to the position Y1 (YES in S111), the control unit 110 displays a corrected image obtained by performing distortion correction according to the angle of the position Y1 at the position Y1 among the pixels of the display element 125. It displays on the display area according to an angle, and makes it project (S112). Here, as described above, the control unit 110 may identify the angle of the concave mirror 140 based on the position control signal, or may identify the angle from the position of the slide resistance of the drive unit 150. Further, in step S112, the virtual image V is visually recognized through the windshield 11 by the driver U from the time when the concave mirror 140 is at the position Y1.

  Then, when the concave mirror 140 moves to the position Y2 (YES in S121), the control unit 110 displays a corrected image that has been subjected to distortion correction according to the angle of the position Y2 as the angle of the position Y12 among the pixels of the display element 125. Is displayed in a display area corresponding to the projection area (S122). Thereafter, the control unit 110 repeats the same processing as steps S112 and S122 according to the angle at the position where the concave mirror 140 has moved. Note that, when the display target image is video data, the head-up display device 100 repeats processing equivalent to steps S112 and S122 for each frame. As a result, the driver U can view the video of the virtual image V displayed corresponding to each angle continuously with little discomfort.

  After that, when the concave mirror 140 moves to the user display setting position Z (YES in S131), the control unit 110 displays a corrected image that has been subjected to distortion correction according to the angle of the user display setting position Z as a pixel of the display element 125. Are displayed in a display area corresponding to the angle of the user display setting position Z and projected (S132). Then, the concave mirror 140 completes the movement to the user display setting position Z (S140), and the head-up display device 100 completes the activation process (S150).

  Next, the relationship between the angle of the concave mirror, the display area of the display element, and the virtual image will be described by comparing the related art with this embodiment. FIG. 7 is a diagram for explaining the relationship between the angle of the concave mirror, the display area of the display element, and the virtual image according to the related art. FIG. 8 is a diagram for explaining the relationship between the angle of the concave mirror, the display area of the display element, and the virtual image according to the first embodiment. Note that the display area of the display element at the user display setting position Z is actually corrected for distortion, but here is rectangular for ease of explanation.

  7 shows the concept of the optical path at the position (angle) of the concave mirror 140, as in FIG. That is, in the case of the position Y1, the display light reflected from the concave mirror 140 passes through the optical path L3W different from the optical path L3Z. 7 shows the display target image displayed on the display element and the display position in the display element, that is, the display area. As described above, in the related art, the display area of the display element 125 is constant regardless of the angle of the concave mirror 140, and distortion correction according to the angle is not performed. Therefore, as shown in the rightmost column of FIG. 7, the display position of the virtual image V is lower in the position Y1 than in the case of the user display setting position Z, and the entire image is not completely displayed. Further, in the case of the position Y1, compared to the case of the user display setting position Z, the shape of the virtual image V is distorted. That is, in the related art, when the concave mirror 140 is in the position Y1, the driver U cannot visually recognize the virtual image V over the windshield 11 at the display position in the normal operation and in the normal shape. Therefore, in the related art, when the concave mirror 140 is in the position Y1, the driver U cannot accurately grasp all display contents of the virtual image V. In the related art, the driver U can visually recognize the virtual image V through the windshield 11 in the normal operation display position and in a normal shape only when the concave mirror 140 is in the user display setting position Z. Will be able to. For this reason, in the related art, after the power is turned on to the head-up display device, the time required for the driver U to visually recognize the virtual image V in the normal operation display position and in the normal shape through the windshield 11. long.

  On the other hand, in the leftmost column of FIG. 8, the display light reflected by the concave mirror 140 passes through the same optical path L3Z at each of the positions Y1, Y2, and Z. Specifically, the display position of a specific point on the display element 125 is different in each of the positions Y1, Y2, and Z. For example, when the concave mirror 140 is at the angle of the position Y2, the display light is reflected by the reflecting mirror 130 via the optical path L1Y2, and is reflected by the concave mirror 140 at the position Y2 via the optical path L2Y2. Therefore, the display light is reflected by the windshield 11 via the optical path L3Z and incident on the eyes of the driver U via the optical path L4Z, as in the case of the angles of the user display setting position Z and the position Y1. To do. Then, the driver U can visually recognize the specific point through the windshield 11 at the position PVZ.

  8 indicates that the position of the display area of the display element 125 differs depending on the angle of the concave mirror 140. It also indicates that the degree of distortion correction for the display target image varies depending on the angle of the concave mirror 140. However, as described above, since the display light passes through the same optical path L3Z regardless of the angle of the concave mirror 140, as shown in the rightmost column of FIG. 8, windshields are provided at positions Y1, Y2, and Z, respectively. 11, the virtual image V having the same display position and shape can be visually recognized.

  In addition, from the above, the rotation reflection unit rotates so that the display light projected from the projection unit is projected from a state where the display light is not projected onto the projection surface, and the control unit It can be said that the display area is adjusted so that the virtual image is visually recognized at a predetermined display position on the projection surface during the rotation of the rotation reflection unit.

  From the above, according to the present embodiment, it is possible to reduce the time required until the display content of the virtual image can be visually recognized at a predetermined display position after the HUD is turned on. In particular, in the present embodiment, as described above, the display area of the projection unit is adjusted according to the angle of the concave mirror, so that the driver U can display the display content of the virtual image V at the normal display position while the concave mirror 140 is rotating. Visual recognition can be started. That is, the driver U can start visualizing the virtual image V faster than the related art. Then, a virtual image that maintains the same visibility as the normal operation can be viewed for a longer time.

  Here, since the distance between the windshield and the HUD, the angle of the windshield, the degree of curvature, etc. are different for each vehicle, in this embodiment, not all the pixels of the display element are used, but one of all the pixels of the display element. Leave the part to use. For example, drawing is performed using pixels near the center of the display element, and the peripheral portion is not used with a margin. In the present embodiment, a virtual image can be visually recognized at a normal operation display position faster by effectively using a region that is not used as a display region during normal operation.

  Further, in the present embodiment, as described above, a corrected image whose distortion has been corrected according to the angle of the concave mirror is projected, so that even if the driver U is rotating the concave mirror 140, the image content and fine details are projected. A character or the like can be visually recognized as a clear virtual image V more quickly. Therefore, the final display position and the virtual image of the shape can be visually recognized from the beginning of the activation of the HUD.

  Note that this embodiment is not limited to when the HUD is activated, but can also be applied when the power of the HUD is turned off. This makes it possible to visually recognize a virtual image having a longer and accurate display position and shape even at the end of the HUD.

<Other embodiments of the invention>
Although the present invention has been described with reference to the above embodiment, the present invention is not limited only to the configuration of the above embodiment, and within the scope of the invention of the claims of the present application. It goes without saying that various modifications, corrections, and combinations that can be made by a trader are included.

  Further, the arbitrary processing of the communication device described above can be realized by causing a CPU (Central Processing Unit) to execute a computer program. In this case, the computer program can be stored using various types of non-transitory computer readable media and supplied to the computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (eg flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg magneto-optical disks), CD-ROM (Read Only Memory), CD-R, CD-R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)) are included. The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

  In addition to the case where the function of the above-described embodiment is realized by the computer executing the program that realizes the function of the above-described embodiment, this program is not limited to the OS ( A case where the functions of the above-described embodiment are realized in cooperation with an operating system or application software is also included in the embodiment of the present invention. Furthermore, the present invention is also applicable to the case where the functions of the above-described embodiment are realized by performing all or part of the processing of the program by a function expansion board inserted into the computer or a function expansion unit connected to the computer. It is included in the embodiment.

DESCRIPTION OF SYMBOLS 1 Car 10 Dashboard 11 Windshield 12 Steering wheel U Driver V Virtual image 100 Head up display apparatus 110 Control part 111 Drive control part 112 CPU
113 Projection Control Unit 114 Display Control Unit 120 Projection Unit 121 Light Source 122 Light Tunnel 123 Fresnel Lens 124 Diffusion Plate 125 Display Element 130 Reflective Mirror 140 Concave Mirror 150 Drive Unit 160 Storage Unit 161 Correction Image 162 Correction Image X Sunlight Retraction Position Y1 Position Y2 Position Z User display setting position

Claims (8)

A projection unit that projects display light corresponding to an image viewed as a virtual image via the projection surface;
A rotation reflecting portion that is rotatably provided and reflects the display light toward the projection surface;
A drive unit that changes the angle of reflecting the display light by rotating the rotation reflection unit;
A control unit that adjusts a display area of the image in the projection unit according to the angle so that the virtual image is visually recognized at a predetermined display position on the projection plane;
An image display device comprising: The controller is
The image display apparatus according to claim 1, wherein the display unit projects the display light corresponding to the image, the distortion of which is corrected according to the angle, so that the virtual image is visually recognized in a predetermined shape on the projection surface. . The projection unit includes a display element including a plurality of pixels,
The controller is
A part of the plurality of pixels in the display element as the display area of the entire image;
The display area is adjusted by changing a pixel corresponding to the image according to the change of the angle so that the virtual image is visually recognized at a predetermined display position on the projection plane. Image display device. A storage unit that stores in advance a plurality of corrected images that are distortion-corrected according to the angle so that the virtual image is visually recognized in a predetermined shape on the projection plane;
The controller is
The image display according to any one of claims 1 to 3, wherein the correction image associated with the angle is read from the storage unit, and the display light corresponding to the read correction image is projected onto the projection unit. apparatus. The controller is
The angle is identified by a control signal for rotating the rotation reflection unit with respect to the drive unit,
The image display device according to claim 1, wherein the display area is adjusted according to the identified angle. The rotating reflection part is
The display light projected from the projection unit is rotated so as to be projected from a state where it is not projected onto the projection surface,
The controller is
The image display according to claim 1, wherein the display area is adjusted so that the virtual image is visually recognized at a predetermined display position on the projection plane during the rotation of the rotation reflection unit. apparatus. A projection unit that projects display light corresponding to an image viewed as a virtual image via the projection surface;
A rotation reflecting portion that is rotatably provided and reflects the display light toward the projection surface;
A drive unit for rotating the rotation reflection unit;
An image display method in an image display device comprising:
Instructing the drive unit to rotate the rotation reflection unit so as to change an angle at which the display light is reflected; and
Adjusting the display area of the image in the projection unit according to the angle so that the virtual image is visually recognized at a predetermined display position on the projection plane;
An image display method including: A projection unit that projects display light corresponding to an image viewed as a virtual image via the projection surface;
A rotation reflecting portion that is rotatably provided and reflects the display light toward the projection surface;
A drive unit for rotating the rotation reflection unit;
On a computer with
Instructing the drive unit to rotate the rotation reflection unit so as to change an angle at which the display light is reflected; and
Adjusting the display area of the image in the projection unit according to the angle so that the virtual image is visually recognized at a predetermined display position on the projection plane;
An image display program that executes