JP2023065276A - Image projection device and image projection method - Google Patents

Abstract

To provide an image projection device and image projection method, which improve visibility of an image by suppressing fluctuation of imaging position due to vehicle vibration while securing effective image display area.SOLUTION: An image projection device (100) for irradiating a display unit for displaying a virtual image with a projection image is provided, the image projection device (100) comprising an image irradiation unit (10) for irradiating a first image, a first optical unit (30) configured to irradiate the first image as first image light via the display unit in a viewing direction, a vibration sensing unit (50) for sensing vibration, and a first optical drive unit (70) configured to change an incident angle of the first image light with respect to the display unit according to vibration information.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image projection device and an image projection method, and more particularly to an image projection device and an image projection method for projecting a projection image onto a display section for displaying a virtual image.

2. Description of the Related Art Conventionally, as a device for displaying various types of information in a vehicle, a dashboard that displays icons by lighting has been used. In addition, as the amount of information to be displayed increases, it has been proposed to embed an image display device in the instrument panel or to configure the entire instrument panel with an image display device.

However, since the instrument panel is located below the vehicle's windshield (windshield), it is necessary for the driver to move his or her line of sight downward while driving in order to see the information displayed on the instrument panel. I don't like it because Therefore, a head-up display (hereinafter referred to as HUD: Head Up Display) has been proposed that projects an image onto the windshield so that the driver can read information when looking ahead of the vehicle (for example, Patent Document 1). , 2).

JP 2019-119248 A JP 2019-119262 A

It has also been proposed to use a driving assistance HUD device to project multiple images onto the windshield in order to present more information. However, in order to project and form multiple images as virtual images at different distances, it is necessary to have multiple image irradiation units and projection optical systems. I had a problem with it being low. Therefore, the applicant of the present application has proposed an image projection apparatus that displays a plurality of images in one image irradiation unit and splits the optical path of each image by a light splitting unit such as a prism to save space. .

FIG. 6 is a schematic diagram showing a prior art image projection device for projecting a plurality of images on one screen. As shown in FIG. 6, the conventional image projection device includes an image irradiation section 1, a reflecting mirror 2, a free-form surface mirror 3, a light branching section 4, a free-form surface mirror 5, and a windshield 6. . In such an image projection device, part of the light emitted from the image irradiation unit 1 is branched by the light branching unit 4 and reflected by the free-form surface mirror 5, the free-form surface mirror 3, and the windshield 6, and is reflected by the driver's viewpoint. , and a virtual image 8 is formed in the distance. Another part of the light emitted from the image irradiation unit 1 is reflected by the reflecting mirror 2, the free-form surface mirror 3, and the windshield 6, reaches the driver's viewpoint, and forms a virtual image 7 in the vicinity. .

Therefore, in the image projection device of the prior art, the virtual image 8 is projected several degrees below the horizontal direction and far away (about 15 m from the driver in FIG. 6), allowing the driver to move the line of sight to visually recognize the driving support information. can be made smaller. Further, a virtual image 7 is projected further downward near (about 3 m from the driver in FIG. 6), and by moving the line of sight, the vehicle speed display and the like can be visually recognized well. However, when the vehicle is running, the vehicle itself and the image projection device vibrate depending on the driving conditions and the road surface conditions, so there is a problem that the imaging positions of the virtual images 7 and 8 are displaced by the vibrations, resulting in a decrease in visibility. there were.

FIG. 7 is a schematic diagram showing a display area displayed by the image irradiation unit 1 in the conventional image projection device. In the image irradiation unit 1, the total display area 1a indicates the entire area in which an image can be displayed. The entire display area 1a is provided with a near display area 1b for displaying a near image and a far display area 1c for displaying a far image. In the image projection apparatus shown in FIG. 6, the light that irradiates the near image displayed in the near display area 1b forms a virtual image 7 in the near area via the reflecting mirror 2, and is displayed in the far display area 1c. The light that irradiates the distant image is imaged as a virtual image 8 in the distance via the light branching portion 4 . However, since the vehicle and the image projection device vibrate when the vehicle is running, the imaging positions of the virtual images 7 and 8 fluctuate with respect to the background, and the visibility of the image deteriorates.

In order to suppress the change in the imaging positions of the virtual images 7 and 8 due to the vibration of the vehicle during travel, a sensor for detecting the vibration of the vehicle is provided. A method of correcting the image display position is conceivable. When the sensor detects vibration of the vehicle, it calculates the vibration direction and the amount of displacement, and changes the display positions of the near display area 1b and the far display area 1c within the margin areas 1d and 1e, respectively. As a result, the displacement of the virtual images 7 and 8 due to vibration is offset by the displacement within the margin areas 1d and 1e, thereby suppressing the change in the imaging positions of the near image and the far image.

However, in such a method of changing the display positions of the near display area 1b and the far display area 1c within the margin areas 1d and 1e, the margin areas 1d and 1e are secured within the entire display area 1a in order to cancel the vibration. need to keep For example, as shown in FIG. 7, when a displacement amount of about 15% is secured above and below the near display area 1b and the far display area 1c, the displayable image size is reduced by 30%. do. Therefore, the image size that can be formed as the virtual images 7 and 8 cannot be increased, and the visibility of the near image and the far image displayed as the virtual images 7 and 8 is deteriorated.

SUMMARY OF THE INVENTION Accordingly, the present invention has been devised in view of the above-described problems of the prior art. An object of the present invention is to provide an image projection device and an image projection method capable of

In order to solve the above problems, an image projection device according to the present invention is an image projection device for irradiating a projection image onto a display unit for displaying a virtual image, the image projection device for irradiating a first image; a first optical unit that irradiates the first image as first image light in a viewpoint direction through the display unit; and a first optical unit that changes an incident angle of the first image light with respect to the display unit based on vibration information. and a drive unit.

In such an image projection apparatus of the present invention, the correction amount of the incident angle of the first image light with respect to the display section is calculated based on the vibration information, and the first optical driving section is controlled according to the correction amount to Since the imaging position of one image is corrected, it is possible to improve the visibility of the image by suppressing the fluctuation of the imaging position due to the vibration of the vehicle while securing an effective image display area.

Further, in one aspect of the present invention, a vibration detection unit that detects vibration and acquires the vibration information, calculates a correction amount of the incident angle based on the vibration information, and calculates the correction amount of the incident angle according to the correction amount. and a correction control unit that controls the driving unit to correct the imaging position of the first image.

In one aspect of the present invention, the image irradiation section further includes a second optical section that irradiates a second image and irradiates the second image as second image light in a viewpoint direction through the display section.

Further, in one aspect of the present invention, the imaging position of the virtual image is farther from the viewpoint position in the first image than in the second image.

Further, in one aspect of the present invention, a light branching section for branching the first image light and the second image light is provided, and the first optical driving section changes an angle of the light branching section with respect to the image irradiation section. do.

Moreover, in one aspect of the present invention, the light branching section is a prism.

Further, in one aspect of the present invention, the apparatus further includes a second optical driving section that changes an incident angle of the second image light with respect to the display section based on the vibration information.

Moreover, in one aspect of the present invention, the first optical drive section changes the angle of any one of the optical members that constitute the first optical section.

Further, in order to solve the above problems, an image projection method of the present invention is an image projection method for projecting a projection image onto a display unit for displaying a virtual image, wherein a first image is projected through the display unit. an image irradiation step of irradiating the first image light in a viewpoint direction; a vibration detection step of acquiring vibration information; and changing an incident angle of the first image light to the display unit based on the vibration information, and a correction control step of correcting the imaging position of the first image.

It is an object of the present invention to provide an image projection apparatus and an image projection method capable of improving the visibility of an image by suppressing fluctuations in the imaging position due to vehicle vibration while ensuring an effective image display area. can be done.

1 is a block diagram showing the configuration of an image projection device 100 according to a first embodiment; FIG. 1 is a schematic diagram showing the configuration of an image projection device 100 according to a first embodiment; FIG. 2 is a schematic diagram showing a display area of an image irradiated from an image irradiation unit 10 in the image projection device 100 according to the first embodiment; FIG. 4 is a flowchart showing steps of an image projection method according to the first embodiment; FIG. 3 is a schematic diagram showing the configuration of an image projection device 110 according to a second embodiment; 1 is a schematic diagram showing a prior art image projection device for projecting multiple images on one screen; FIG. 1 is a schematic diagram showing a display area of an image displayed by an image irradiation unit 1 in a conventional image projection device; FIG.

(First embodiment)
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or equivalent constituent elements, members, and processes shown in each drawing are denoted by the same reference numerals, and duplication of description will be omitted as appropriate. FIG. 1 is a block diagram showing the configuration of an image projection device 100 according to this embodiment. As shown in FIG. 1, the image projection device 100 includes an image irradiation unit 10, a light branching unit 20, a first optical unit 30, a second optical unit 40, a vibration detection unit 50, a correction control unit 60, An optical drive unit 70 is provided. The light projected from the image projection device 100 is irradiated to the driver's viewpoint position through a windshield (display unit) not shown.

The image projection apparatus 100 also includes a control section (not shown) that is connected to each section so as to be able to communicate with each other and controls each section. Although the configuration of the control unit is not limited, one example includes a CPU (Central Processing Unit) for performing information processing, a memory device, a recording medium, an information communication device, and the like. The control section controls the operation of each section according to a predetermined program, and sends information (image information) including an image to the image irradiation section 10 .

The image irradiation section 10 is a section that irradiates light containing an image based on the image information from the control section. The specific configuration of the image irradiation unit 10 is not limited, and conventionally known devices such as a liquid crystal display device, an organic EL display device, and a combination of a laser light source and an optical modulation element can be used. In the example shown in FIG. 1, light is emitted from the rear side of the liquid crystal display device using a light emitting diode (LED). As will be described later, the image irradiation unit 10 includes a far display area 13 and a near display area 12 that display a far image and a near image, respectively.

The light splitting unit 20 is an optical member that splits the image light emitted from the image irradiating unit 10 . The second image to be displayed is branched as second image light. The structure of the light splitting unit 20 is not limited as long as it is an optical member that splits light. A prism may be used, or a technique such as using a reflecting mirror to make the incident angle and the reflection angle of light different may be used. In the example shown in FIG. 2, a prism is used as the light branching section 20 and the prism is arranged so as to overlap the distant display area 13 of the image irradiation section 10 . Therefore, the first image light emitted from the distant display area 13 is reflected by the free-form surface mirror 41 through a path different from that of the second image light by the light splitter 20 and reaches the free-form surface mirror 32 . Also, the second image light emitted from the near display area 12 is reflected by the reflecting mirror 31 and reaches the free-form surface mirror 32 .

Here, arranging the light branching unit 20 so as to overlap the image irradiation unit 10 means that the area where the light branching unit 20 is arranged overlaps the image display area of the image irradiation unit 10 in plan view. In addition, both the case where the light branching unit 20 and the image irradiation unit 10 are in contact with each other and the case where they are not in contact are included in the overlapping arrangement. Also, a case in which an optical member that transmits light or a holding member that maintains the distance between the light branching unit 20 and the image irradiation unit 10 is interposed is also included in the overlapping arrangement.

The first optical unit 30 is a combination of optical elements that irradiate the distant image displayed in the distant display area 13 as first image light in the viewing direction through the display unit. The optical configuration of the first optical unit 30 is not limited, and may be a combination of a plurality of reflecting mirrors, lenses, prisms, and the like. The second optical unit 40 is a combination of optical elements that irradiate the near image displayed in the near display area 12 as second image light in the viewing direction via the display unit. The optical configuration of the second optical section 40 is not limited, and may be a combination of a plurality of reflecting mirrors, lenses, prisms, and the like.

The vibration detection unit 50 is a part that detects vibration during running of a vehicle in which the image projection device 100 is mounted and acquires vibration information. A specific configuration of the vibration detection unit 50 is not limited, but a conventionally known acceleration sensor such as a gyro sensor can be used. Here, the case where the vibration detection unit 50 is provided inside the image projection device 100 is shown, but vibration information is acquired by the vibration detection unit 50 separately provided outside the image projection device 100, and information communication means is used. The image projection device 100 may obtain the vibration information by transmitting the vibration information to the control unit of the image projection device 100 .

The correction control unit 60 calculates the correction amount of the incident angle of the first image light from the first optical unit 30 to the display unit based on the vibration information acquired by the vibration detection unit 50, and performs optical driving according to the correction amount. This is the part that controls the unit 70 to correct the imaging position of the first image. The correction control section 60 is a function realized by a program executed by the control section, and executes each step according to a predetermined procedure. Although the correction control unit 60 is provided inside the image projection apparatus 100 here, the correction amount is calculated based on the vibration information by the correction control unit 60 separately provided outside the image projection apparatus 100, and the information The correction amount may be communicated using communication means. Further, a control signal for the optical driving section 70 may be generated based on the correction amount calculated outside, and driving of the optical driving section 70 may be controlled using information communication means.

The optical drive section 70 is a section that changes the incident angle of the first image light with respect to the display section by changing the optical path of the first optical section 30 . Although the configuration of the optical drive unit 70 is not limited, for example, a motor device that changes the angles of the first optical unit 30 and the light branching unit 20, an optical element that electrically controls the traveling direction of light, and the like can be used. The optical drive section 70 corresponds to the first optical drive section in the present invention. When a motor device is used as the optical drive unit 70, it is preferable to use a stepping motor capable of precisely controlling the rotation angle.

FIG. 2 is a schematic diagram showing the configuration of the image projection device 100 according to this embodiment. As shown in FIG. 2, the image projection device 100 includes an image irradiation unit 10, a light branching unit 20, a vibration detection unit 50, a correction control unit 60, an optical driving unit 70, a reflecting mirror 31, and a free-form surface mirror. 32, a free-form surface mirror 41, and an external light cut filter 80. Here, the combination of the free-form surface mirror 41 and the free-form surface mirror 32 constitutes the first optical section 30 in the present invention. It constitutes the second optical section 40 in the invention.

In the example shown in FIG. 2, part of the light emitted from the image irradiation unit 10 passes through the first optical unit 30 and the windshield (display unit) to irradiate the first image light in the viewing direction. Another part of the light emitted from the image irradiation unit 10 irradiates the second image light in the viewpoint direction through the second optical unit 40 and the windshield (display unit). A convex lens or a concave lens may be arranged in the first optical section 30 or the second optical section 40 as necessary to enlarge or reduce the light diameter. Also, the arrangement and orientation of the light branching section 20, the reflecting mirror 31, the free-form surface mirror 32, the free-form surface mirror 41, and the external light cut filter 80 are not limited to those shown in FIG.

The reflecting mirror 31 is an optical member that receives the second image light emitted from the image irradiation unit 10 and reflects the first image light toward the free-form surface mirror 32 . In the example shown in FIG. 2, a convex mirror is shown as the reflecting mirror 31, but it is possible to use a mirror that is optically designed to project the first image light as a virtual image. A concave mirror, a plane mirror, a free-form surface mirror, or the like can be used. Alternatively, the reflecting mirror 31 may be omitted, and the first image light from the image irradiation unit 10 may directly enter the free-form surface mirror 32 .

The free-form surface mirror 32 is a concave mirror that receives the second image light reflected by the reflecting mirror 31 and reflects the second image light in the direction of the windshield. The reflecting surface of the free-form surface mirror 32 is designed so that the light diameter expands in the direction of the driver's viewpoint in order to project a virtual image through the windshield. Here, the expansion of the light diameter in the viewing direction includes not only the case where the light diameter is consistently expanded after reflection, but also the case where the light diameter is reduced and expanded after forming an image at an intermediate point.

The free-form surface mirror 41 is an optical member that receives the first image light through the light branching unit 20 and reflects the first image light toward the free-form surface mirror 32 . The reflecting surface of the free-form surface mirror 41 is designed so that the light diameter expands in the direction of the driver's viewpoint in order to project a virtual image through the windshield. Here, the expansion of the light diameter in the viewing direction includes not only the case where the light diameter is consistently expanded after reflection, but also the case where the light diameter is reduced and expanded after forming an image at an intermediate point.

The external light cut filter 80 is arranged on the path of the first image light between the image irradiation unit 10 and the windshield, and has wavelength characteristics of blocking infrared light and/or ultraviolet light and transmitting visible light. It is an optical member. FIG. 2 shows an example in which the external light cut filter 80 is arranged between the windshield and the free-form surface mirror 32, but if the external light entering the image irradiation unit 10 can be cut, the place of arrangement is limited. not. By arranging the external light cut filter 80, infrared light and/or ultraviolet light contained in external light such as sunlight entering from above the windshield is blocked. As a result, it is possible to suppress temperature rise and deterioration of the display surface when sunlight reaches the image display area of the image irradiation unit 10 via the free-form surface mirror 32 , the reflecting mirror 31 and the free-form surface mirror 41 . In addition, since the external light cut filter 80 transmits visible light, the first image light passes well through the external light cut filter 80 and does not affect the projection of the virtual image.

A windshield (not shown) is a portion that is provided in front of the driver's seat of the vehicle and transmits visible light. Since the windshield reflects the first image light and the second image light incident from the free-form surface mirror 32 on the inner surface of the vehicle in the direction of the viewpoint, and transmits light from the outside of the vehicle in the direction of the viewpoint, It corresponds to the display section in the present invention. Although an example using a windshield as the display section is shown here, a combiner may be prepared as a display section separately from the windshield to reflect the light from the free-form surface mirror 32 in the direction of the viewpoint. Further, the position is not limited to the position in front of the vehicle, and may be positioned to the side or rear as long as it projects an image to the viewpoint of the passenger.

The virtual image is an image that is displayed as if it were formed in space when the first image light and the second image light reflected by the windshield reach the visual point (eye box) of the driver or the like. The position where the virtual image is formed is the spread angle when the light irradiated from the image irradiation unit 10 travels in the direction of the viewpoint after being reflected by the reflecting mirror 31, the free-form surface mirror 32, the free-form surface mirror 41, and the windshield. determined by

In the example shown in FIG. 2, the optical driving section 70 is configured by a stepping motor, and the angle of the light branching section 20 is changed. In this embodiment, the correction control unit 60 calculates a correction amount based on the vibration information acquired by the vibration detection unit 50 and sends a control signal to the optical drive unit 70 while the vehicle is running. The optical driving section 70 is driven according to the control signal, the light branching section 20 is rotated about the direction perpendicular to the plane of the drawing as a rotation axis, and the relative angle to the image irradiation section 10 is changed. As a result, the optical path of the first image light after passing through the light branching unit 20 is changed, and the imaging position of the distant image moves in the vertical direction of the paper surface.

FIG. 3 is a schematic diagram showing a display area of an image irradiated from the image irradiation unit 10 in the image projection device 100 according to this embodiment. The entire display area 11 is the entire area where the image of the image irradiation unit 10 is displayed. A part of the total display area 11 is a near display area 12 and another part is a far display area 13 . A first image is displayed in the far display area 13 and a second image is displayed in the near display area 12 . The second image displayed in the near display area 12 includes a speed and volume indicator, a traveling direction guide, and the like. Further, the first image displayed in the distant display area 13 includes supplementary information related to driving such as an image calling attention and emergency information.

In the image projection apparatus 100 shown in FIG. 2, a prism, which is the light branching unit 20, is arranged at a position overlapping the far display area 13, and the first image light from the far display area 13 and the second image light from the near display area 12 are arranged. The path of the image light is branched. The first image displayed in the distant display area 13 reaches the driver's viewpoint via the light splitter 20, the free-form surface mirror 41, the free-form surface mirror 32, the external light cut filter 80, and the windshield. Also, the second image displayed in the near display area 12 reaches the driver's viewpoint via the reflecting mirror 31, the free-form surface mirror 32, the external light cut filter 80, and the windshield. The first image light and the second image light reach the viewpoint after being enlarged in diameter by the first optical unit 30 and the second optical unit 40, respectively. A virtual image of the 1st image and the 2nd image light is viewed as if it were formed at a predetermined distance. Here, the imaging position of the virtual image is farther from the viewpoint position in the first image than in the second image.

FIG. 4 is a flow chart showing the steps of the image projection method according to this embodiment. First, in the image irradiation step of step S1, the near display area 12 of the image irradiation unit 10 displays a near image (second image), the far display area 13 displays a far image (first image), and They are irradiated as the second image light and the first image light. The irradiation of the first image light and the second image light and the formation of the virtual image are the same as those described above. After performing the irradiation of the first image light and the second image light, the process proceeds to step S2.

Next, in the vibration detection process of step S2, the vibration detection unit 50 detects vibration of the vehicle, acquires vibration information, and sends the acquired vibration information to the correction control unit 60. FIG. As a specific example, when an acceleration sensor is used for the vibration detection unit 50, the acceleration information detected by the acceleration sensor is sent to the correction control unit 60 as vibration information. Alternatively, the acceleration information detected by the acceleration sensor is integrated within a predetermined period to calculate the amount of change in velocity and position, and the amount of change in position is sent to the correction control section 60 as vibration information. After transmitting the vibration information to the correction control unit 60, the process proceeds to step S3.

Next, in the correction amount calculation step of step S3, the correction control section 60 generates a control signal for the optical driving section 70 based on the acquired vibration information. When acceleration information is acquired as vibration information, the amount of change in velocity and position is calculated by integration within a predetermined period, and the amount of change in position is converted into the amount of change in the angle of incidence on the windshield. Also, the rotation angle of the optical path in the first optical section 30 is calculated from the amount of change in the angle of incidence on the windshield, and a control signal is generated to change the optical path of the first optical section 30 in the opposite direction of the rotation angle. do. As an example, when a prism that is the light branching unit 20 is provided in the optical drive unit 70 and the relative angle of the light branching unit 20 to the image irradiation unit 10 is changed, the refractive index of the light branching unit 20 and the first image The angle of rotation is determined in consideration of the angle of incidence of light. After generating the control signal, the correction control section 60 sends the control signal to the optical driving section 70, and the process proceeds to step S4.

Next, in the correction control process of step S4, the optical drive section 70 is driven to change the optical path of the first optical section 30 based on the control signal generated in the correction amount calculation process. When the optical driving section 70 is provided in the light branching section 20 , the angle of incidence on the free-form surface mirror 41 is changed by rotating the light branching section 20 . As a result, the imaging position of the virtual image is controlled in the direction opposite to the vibration of the vehicle, and the positional deviation from the background caused by the vibration of the vehicle is offset, thereby improving the visibility. After performing drive control of the optical drive unit 70, the process proceeds to step S5.

Next, in step S5, it is determined whether or not the image irradiation method is to be terminated. If not, the process proceeds to step S1 to continue the vibration correction feedback control. When finished, exit from the loop of the feedback control and finish the control. Here, the correction amount calculation process and the correction control process are described as separate processes, but the correction amount calculation may also be performed in the correction control process.

As described above, in the image projection apparatus 100 and the image projection method of this embodiment, the first optical unit 30 is controlled based on vibration information to correct the imaging position of the first image. Since fluctuations in the imaging position due to vibration are optically corrected by feedback control, there is no need to provide a margin area within the entire display area 11 as shown in FIG. Therefore, it is possible to secure an effective image display area, increase the areas of the near display area 12 and the far display area 13, and project large first and second images. As a result, it is possible to improve the visibility of the image by suppressing the fluctuation of the imaging position due to the vibration of the vehicle.

In the present embodiment, an example in which a distant image is emitted as the first image light and a near image is emitted as the second image light is shown. The two image lights may be imaged at a distant position as a distant image. However, in the distant image, the distance from the driver's viewpoint position to the imaging position is long, and the deviation from the background tends to increase due to blurring of the imaging position due to vibration. Therefore, by forming an image of the first image light at a long distance as a distant image and correcting the image forming position based on the vibration information, it is possible to enhance the effect of suppressing the positional deviation from the background and improving the visibility. can.

In addition, by using a prism as the light branching unit 20, positioning and optical design for partially covering the image irradiation unit 10 and branching part of the light are facilitated. In addition, compared to the case of using a reflecting mirror to split light, the use of a prism as the light splitting unit 20 reduces the volume to be secured for splitting the light, thereby miniaturizing the device. can. In addition, since the prism is smaller and lighter than the reflecting mirror 31, the free-form surface mirror 32, the free-form surface mirror 41, etc., the torque when the optical drive unit 70 rotates is small, and the optical drive unit 70 is low in output. Miniaturization can be achieved by using materials. In addition, since the prism is small and lightweight, it is possible to improve the accuracy of the rotational operation and increase the rotational speed during correction.

As described above, in the image projection apparatus and image projection method of the present embodiment, the amount of correction of the incident angle of the first image light with respect to the windshield (display unit) is calculated based on the vibration information, and the optical image is projected according to the amount of correction. The driving unit 70 is controlled to correct the imaging position of the first image. As a result, it is possible to improve the visibility of the image by suppressing the fluctuation of the imaging position due to the vibration of the vehicle while securing an effective image display area.

(Second embodiment)
Next, a second embodiment of the invention will be described with reference to FIG. The description of the content that overlaps with the first embodiment is omitted. FIG. 5 is a schematic diagram showing the configuration of the image projection device 110 according to this embodiment. As shown in FIG. 5, the image projection device 110 includes an image irradiation unit 10, light branching units 20a and 20b, a reflecting mirror 31, a free-form surface mirror 32, a free-form surface mirror 41, a vibration detection unit 50, and a correction unit 50. A control unit 60 , optical drive units 70 a and 70 b , and an external light cut filter 80 are provided. The present embodiment differs from the first embodiment in that optical branching units 20a and 20b and optical driving units 70a and 70b are provided, and both the first optical unit 30 and the second optical unit 40 perform vibration correction. .

In the image projection device 110 shown in FIG. 5, the light splitter 20a is arranged at a position overlapping the distant display area 13 to split the first image light from the far display area 13 toward the free-form surface mirror 41. The optical splitter 20a corresponds to the first optical splitter in the present invention. Further, a light branching portion 20 b is arranged at a position overlapping the near display area 12 to branch the second image light from the near display area 12 toward the reflecting mirror 31 . The optical splitter 20b corresponds to the second optical splitter in the present invention.

In the image projection device 110, the first image displayed in the distant display area 13 is projected to the driver's viewpoint through the light branching section 20a, the free-form surface mirror 41, the free-form surface mirror 32, the external light cut filter 80, and the windshield. reach. Also, the second image displayed in the near display area 12 reaches the driver's viewpoint via the light splitter 20b, the reflecting mirror 31, the free-form surface mirror 32, the external light cut filter 80, and the windshield.

The optical driving units 70a and 70b are provided in the light branching units 20a and 20b, respectively, and change the relative angle with respect to the image irradiation unit 10, and correspond to the first optical driving unit and the second optical driving unit in the present invention, respectively. are doing. The vibration detection unit 50 and the correction control unit 60 detect the vibration of the vehicle and individually control the optical drive units 70a and 70b based on the vibration information to detect the imaging positions of the first image and the second image due to the vibration. to compensate for variations in

Also in the image projection apparatus and image projection method of the present embodiment, the correction amount of the incident angle of the first image light and the second image light with respect to the windshield (display unit) is calculated based on the vibration information, and the correction amount is calculated according to the correction amount. The imaging positions of the first image and the second image are corrected by controlling the optical drive units 70a and 70b. As a result, it is possible to improve the visibility of the image by suppressing the fluctuation of the imaging position due to the vibration of the vehicle while securing an effective image display area.

(Third embodiment)
Next, a third embodiment of the invention will be described. The description of the content that overlaps with the first embodiment is omitted. In the first and second embodiments, the light branching unit 20 is used to branch the light emitted from the image irradiating unit 10, and a far image and a near image are projected at different distances to form virtual images. was However, one image may be displayed by the image irradiation unit 10 and one virtual image may be formed by the first optical unit 30 without using the light branching unit 20 and the second optical unit 40 . In this case, the optical drive unit 70 can be provided in the free-form surface mirror 41 to change the relative angle of the free-form surface mirror 41 with respect to the image irradiation unit 10 . At this time, the control of the optical drive unit 70 is the same as that of the first embodiment. A control signal for controlling driving of the unit 70 is generated.

Also in the image projection apparatus and image projection method of this embodiment, the correction amount of the incident angle of the first image light with respect to the windshield (display unit) is calculated based on the vibration information, and the optical drive unit 70 is operated according to the correction amount. control to correct the imaging positions of the first image and the second image. As a result, it is possible to improve the visibility of the image by suppressing the fluctuation of the imaging position due to the vibration of the vehicle while securing an effective image display area.

The present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 100, 110... Image projection apparatus 10... Image irradiation part 11... Entire display area 12... Near display area 13... Far display area 20, 20a, 20b... Light branching part 30... First optical part 31... Reflecting mirrors 32, 41 ...Free-form surface mirror 40...Second optical unit 50...Vibration detection unit 60...Correction control units 70, 70a, 70b...Optical driving unit 80...External light cut filter

Claims (9)

An image projection device for projecting a projection image onto a display unit for displaying a virtual image,
an image irradiating unit that irradiates the first image;
a first optical unit that irradiates the first image as first image light in a viewpoint direction through the display unit;
An image projection apparatus, comprising: a first optical driving section that changes an incident angle of the first image light with respect to the display section based on vibration information. The image projection device according to claim 1,
a vibration detection unit that detects vibration and acquires the vibration information;
a correction control unit that calculates a correction amount of the incident angle based on the vibration information, controls the first optical driving unit according to the correction amount, and corrects the imaging position of the first image. An image projection device characterized by: The image projection device according to claim 1 or 2,
The image irradiation unit further irradiates a second image,
An image projection apparatus, comprising: a second optical unit that irradiates the second image as second image light in a viewpoint direction through the display unit. The image projection device according to claim 3,
The image projection device, wherein the imaging position of the virtual image is farther from the viewpoint position in the first image than in the second image. The image projection device according to claim 3 or 4,
A light branching unit that branches the first image light and the second image light,
The image projection device, wherein the first optical driving section changes an angle of the light branching section with respect to the image irradiating section. The image projection device according to claim 5,
The image projection device, wherein the light branching section is a prism. The image projection device according to any one of claims 3 to 6,
An image projection apparatus, comprising: a second optical driving section that changes an incident angle of the second image light with respect to the display section based on the vibration information. The image projection device according to any one of claims 1 to 7,
The image projection device, wherein the first optical driving section changes an angle of any one of the optical members constituting the first optical section. An image projection method for projecting a projection image onto a display unit for displaying a virtual image,
an image irradiation step of irradiating a first image as first image light in a viewpoint direction through the display unit;
a vibration detection step of acquiring vibration information;
and a correction control step of correcting an imaging position of the first image by changing an incident angle of the first image light with respect to the display unit based on the vibration information.

Images