Virtual image optical system, virtual image display device equipped with the same, and in-vehicle system

Abstract

To provide a virtual image optical system capable of achieving excellent visibility in spite of a simple structure.SOLUTION: A virtual image optical system 115 capable of forming a virtual image 113 by guiding light from a display surface 101 into a pupil 112 includes a first reflector 102 for reflecting the light from the display surface 101 and a second reflector 103 for reflecting the light from the first reflector 102. The movement of the first reflector 102 can change a light path length from the display surface 101 to the second reflector 103; the rotation of the second reflector 103 can change the position of the pupil 112 in a direction including a component of a direction perpendicular to an optical path of a chief ray incident on the pupil 112; an angle formed by the movement direction of the first reflector 102 and the chief ray incident on the first reflector 102 is 5° or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a virtual image optical system suitable for a virtual image display device that displays a virtual image of an image. [Background technology]

[0002] Conventionally, in moving devices such as vehicles, virtual image display devices such as head-up displays (HUDs) have been used that form a virtual image of an image displayed by a display means in space, allowing a passenger (user) to visually recognize the image. The virtual image display device can display an image in front of the windshield (windshield) of the vehicle as seen by the passenger, and can superimpose the image on the surrounding environment of the vehicle.

[0003] Here, for example, when a passenger checks a vehicle that is farther away than the virtual image, the passenger's viewpoint may change, making it difficult to obtain good visibility. Patent Documents 1 and 2 describe virtual image display devices that can change the relative position between the passenger and the virtual image by moving a movable mirror. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6252883 [Patent Document 2] Japanese Patent Application Publication No. 2018-31861 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the virtual image display devices of Patent Documents 1 and 2, the angle of incidence of light from the display unit changes significantly when the movable mirror is moved, which causes a difference in brightness between the virtual image before and after the movement of the movable mirror, leading to a decrease in visibility for passengers.

[0006] An object of the present invention is to provide a virtual image optical system that has a simple configuration but is capable of achieving good visibility. [Means for solving the problem]

[0007] In order to achieve the above object, one aspect of the present invention provides a virtual image optical system that forms a virtual image by guiding light from a display surface to a pupil, the virtual image optical system having a first reflecting surface that reflects light from the display surface and a second reflecting surface that reflects light from the first reflecting surface, and an optical path length from the display surface to the second reflecting surface can be changed by moving the first reflecting surface; the virtual image can be decentered with respect to a line connecting the center of the pupil and the center of the virtual image by rotating the first reflecting surface; By rotating the second reflecting surface, the position of the pupil can be changed in a direction that includes a component perpendicular to the optical path of the chief ray incident on the pupil, and the angle between the direction of movement of the first reflecting surface and the chief ray incident on the first reflecting surface is 5° or less. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a virtual image optical system that can achieve good visibility despite having a simple configuration. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a virtual image display device according to an embodiment (first state); [Figure 2] Schematic diagram of a virtual image display device according to an embodiment (second state) [Figure 3] Schematic diagram of a virtual image display device according to a modified example [Figure 4] 1 is a schematic diagram of a main part of a virtual image display device according to a first embodiment; [Figure 5] 1 is an enlarged view of a main part of a virtual image display device according to a first embodiment; [Figure 6] 1 is a schematic diagram of a main part of a virtual image display device according to a second embodiment; [Figure 7] 10 is an enlarged view of a main part of a virtual image display device according to a second embodiment; [Figure 8] Schematic diagram of an in-vehicle system and a moving device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Note that the drawings may be drawn at a scale different from the actual scale for convenience. In addition, the same reference numerals are used to designate the same components in the drawings, and redundant explanations will be omitted.

[0011] 1 and 2 are schematic diagrams (YZ cross-sectional views) of a virtual image display device 100 according to an embodiment of the present invention. The virtual image display device 100 includes a display means (display unit) 101 that displays an image, a virtual image optical system 105 that forms a virtual image 113 of the image displayed on the display surface of the display means 101, and a drive means (drive unit) that drives the virtual image optical system 105. FIG. 1 shows a case where the virtual image 113 that is to be viewed by the user of the virtual image display device 100 is positioned on the front side (first position) (first state), and FIG. 2 shows a case where the virtual image 113 that is to be viewed by the user is positioned on the back side (second position) (second state).

[0012] 1 and 2, the optical path 111 (reference axis, optical axis) of the chief ray (reference ray) of the light beam from the display means 101, which passes through the center of the pupil on the reduction side (object side) of the virtual image optical system 105 and reaches the center of the pupil 112 (eye box) on the enlargement side (image side), is shown by a dashed dotted line. Note that although the chief ray does not actually reach the position of each virtual image, Figs. 1 and 2 also show the optical path of the virtual chief ray that reaches the center of the virtual image 113 viewed by the user.

[0013] According to the virtual image display device 100, by forming a virtual image 113 of the image displayed on the display surface of the display means 101, the user can perceive the image as if it were being displayed in front of the windshield (front glass) WS. This makes it possible to superimpose the image on the surrounding environment (external environment) in front of the windshield WS.

[0014] A display element (spatial modulation element) such as a liquid crystal panel can be used as the display means 101. For example, an LCD (Liquid Crystal Display), LCOS (Liquid Crystal On Silicon), or DMD (Digital Mirror Device) can be used as the display means 101. A screen that displays an image projected by a projection means (not shown) may also be used. The display surface of the display means 101 corresponds to the object surface (reduced surface) of the virtual image optical system 105.

[0015] In this embodiment, the display surface of the display means 101 is not perpendicular to the reference axis 111. This prevents light from being specularly reflected by the display surface and reaching the user's eye 104 when it is incident on the display surface, such as sunlight. It is desirable to position the display means 101 so that the chief ray (reference ray) is emitted from the center of the display surface. This improves the light utilization efficiency of the virtual image display device 100.

[0016] The windshield WS is an optical component provided on a mobile object (mobile device) such as an automobile (vehicle) on which the virtual image display device 100 is mounted. The windshield WS reflects light from the virtual image display device 100 toward the eyes 104 of a user (a passenger in the mobile device) and transmits light from the outside toward the user. The transmissive / reflective surface of the windshield WS may be flat or curved as long as it matches the shape of the mobile device. A combiner (half mirror), which is a separate component from the windshield WS, may be used as an optical component having the same function as the windshield WS. Furthermore, the virtual image display device 100 may, if necessary, guide light directly to the user's eyes 104 without passing through the windshield WS.

[0017] The virtual image optical system 105 according to this embodiment has a first reflecting surface 102 (first reflecting optical element) that reflects light from the display means 101, and a second reflecting surface 103 (second reflecting optical element) that reflects light from the first reflecting surface 102. A mirror, a prism, or the like can be used as each reflecting optical element. If necessary, the reflecting surface may be an aspheric surface such as a free-form surface. While this embodiment assumes a configuration in which one reflecting surface is formed on one reflecting optical element, a reflecting optical element having multiple reflecting surfaces may also be used. For example, a single reflecting optical element having the first reflecting surface 102 and the second reflecting surface 103 formed thereon may also be used if necessary.

[0018] The virtual image optical system 105 may include optical components such as a refractive optical element, a catadioptric optical element, and a flat glass (cover glass) as needed. The virtual image optical system 105 may have a positive power throughout the entire system to form each virtual image, and may also include a reflective surface with no power or negative power. However, in order to reduce the size and weight of the entire system, it is preferable to configure the virtual image optical system 105 with only the first reflective surface 102 and the second reflective surface 103, as in this embodiment.

[0019] Next, the features of the virtual image optical system 105 according to this embodiment will be described.

[0020] The virtual image optical system 105 forms a virtual image 113 by guiding light from the display surface of the display means 101 to a pupil 112 via a first reflecting surface 102 and a second reflecting surface 103. Specifically, in the virtual image optical system 105, the light from the display surface is reflected by the first reflecting surface 102 and the second reflecting surface 103 toward the magnification side, and is then guided to the pupil 112 via the windshield WS. At this time, the light reaches the user's eye 104, which is located at the position of the pupil 112, allowing the user to view the virtual image 113.

[0021] The virtual image optical system 105 is configured to be able to change the optical path length from the display surface to the second reflecting surface 103 by moving the first reflecting surface 102. With this configuration, the position of the virtual image 113 viewed by the user can be changed according to changes in the user's viewpoint, thereby providing the user with good visibility. In this embodiment, the first driving means 106 (moving mechanism) serving as driving means moves the first reflecting surface 102 in a direction that includes a component parallel to the optical path of the chief ray incident on the first reflecting surface 102, thereby moving the virtual image 113 in a direction along the optical path of the chief ray (Z direction).

[0022] FIG. 1 shows a first state in which the virtual image display device 100 allows the user to visually perceive the virtual image 113 as being at a first position. FIG. 2 shows a second state in which the position of the first reflecting surface 102 is changed from the first state to make the optical path length from the display surface to the second reflecting surface 103 longer than in the first state. Corresponding to the optical path length from the display surface to the second reflecting surface 103, the optical path length from the pupil 112 to the virtual image 113 is also longer in the second state than in the first state. This allows the virtual image display device 100 to allow the user to visually perceive the virtual image 113 as being at a second position that is farther away than the first position.

[0023] For example, it is desirable to use the first state when the user directs their gaze to a nearby object (such as a vehicle ahead) such as when the mobile device is stopped (when the vehicle is stopped), and to use the second state when the user directs their gaze to a distant object (such as a traffic light or sign) such as when the mobile device is moving at high speed. This reduces the distance between the external world perceived by the user and the virtual image, thereby reducing the burden on the user of changing their line of sight.

[0024] Here, if the movement direction of the first reflecting surface 102 is not appropriately set, the angle of incidence of light from the display surface will change significantly as the first reflecting surface 102 moves, resulting in reduced visibility for the user, as described above. Therefore, in this embodiment, the angle α between the movement direction of the first reflecting surface 102 and the chief ray incident on the first reflecting surface 102 is set to 5° or less. This allows the movement direction of the first reflecting surface 102 to be limited to a direction approximately parallel to the chief ray, thereby reducing the change in the angle of incidence of light from the display surface compared to when α is set to greater than 5°. In other words, the difference in brightness of the virtual image 113 before and after the movement of the first reflecting surface 102 can be reduced, thereby suppressing a decrease in visibility for the user. Note that, when α changes due to the movement of the first reflecting surface 102, it is sufficient to configure α to always be 5° or less regardless of the position of the first reflecting surface 102.

[0025] On the other hand, when the first reflecting surface 102 is moved, the relative position between the pupil 112 and the user's eye 104 is shifted. Therefore, the virtual image optical system 105 according to this embodiment is configured to be able to change the position of the pupil 112 in a direction including a component in a direction (Y direction) perpendicular to the optical path 111 of the chief ray incident on the pupil 112 by rotating (decentering) the second reflecting surface 103. In this embodiment, the position of the pupil 112 can be moved in the Y direction by using second driving means 107 (rotation mechanism) as driving means to rotate the second reflecting surface 103 about an axis parallel to a direction (X direction) perpendicular to a cross section (YZ cross section) including the reference axis.

[0026] According to this configuration, even if the relative position between pupil 112 and user's eye 104 shifts due to movement of first reflecting surface 102, the relative position can be adjusted by rotating second reflecting surface 103. In other words, the position of pupil 112 can be made to coincide with the position of user's eye 104 regardless of the position of first reflecting surface 102, so that good visibility can be provided to the user regardless of the position of virtual image 113.

[0027] In this embodiment, the driving means includes first driving means 106 and second driving means 107. Examples of the driving means include an actuator such as a motor, and an operating means for non-electrically driving each reflecting surface through user operation. The driving means can switch between the first state and the second state described above by driving each reflecting surface based on a signal (information) from an external control means. The driving means may also function as a control means. In this case, the driving means may include a processor such as a CPU (Central Processing Unit). This allows the driving means to control the driving of each reflecting surface.

[0028] In order to further reduce the difference in brightness of the virtual image 113 before and after the movement of the first reflecting surface 102, it is preferable to set α to 3° or less, and more preferably to set α to 1° or less. In this embodiment, by setting α to 0°, the movement direction of the first reflecting surface 102 is made parallel to the chief ray, and the difference in brightness of the virtual image 113 is effectively reduced.

[0029] Furthermore, in order to adjust the position of the pupil 112 with high precision, it is desirable that the rotation center (rotation axis) of the second reflecting surface 103 be located near the incident position of the chief ray on the second reflecting surface 103. In this embodiment, the rotation center of the second reflecting surface 103 is located at an intermediate position between the incident position of the chief ray on the second reflecting surface 103 in the first state and the incident position of the chief ray on the second reflecting surface 103 in the second state. Note that, when the position of the first reflecting surface 102 is also moved to a position different from the first and second states, it is sufficient that the rotation center is located between (an intermediate position) the respective incident positions of the chief ray on the second reflecting surface 103 when the first reflecting surface 102 is at the most reduction side and when the first reflecting surface 102 is at the most enlargement side.

[0030] Furthermore, when the sum of the angle of incidence and the angle of reflection of the chief ray on the first reflecting surface 102 is β, it is desirable to satisfy the following conditional expression (1): If the value of β differs between the first state and the second state, it is desirable to satisfy conditional expression (1) in each state. 30°≦β≦70° (1)

[0031] If the upper limit of conditional expression (1) is exceeded, the deviation of the incident position of the chief ray on the second reflecting surface 103 before and after the movement of the first reflecting surface 102 becomes large, and the amount of rotation of the second reflecting surface 103 required to adjust the relative position between the pupil 112 and the user's eye 104 becomes large. This increases the space required to rotate the second reflecting surface 103, making it difficult to make the entire device compact and lengthening the time required to adjust the second reflecting surface 103. Furthermore, if the lower limit of conditional expression (1) is not reached, the distance between the display means 101 and the second reflecting surface 103 becomes narrow, and there is a risk that part of the light from the first reflecting surface 102 will be blocked by the display means 101.

[0032] Furthermore, it is preferable to satisfy the following conditional expression (1a), and it is more preferable to satisfy the following conditional expression (1b). 35°≦β≦65° (1a) 40°≦β≦60° (1b)

[0033] Furthermore, on the optical path of the chief ray, when the power of the first reflecting surface 102 is φ1 and the power of the second reflecting surface 103 is φ2, it is desirable to satisfy the following conditional expression (2): If the power of each reflecting surface differs between a cross section including the reference axis (yz cross section) and a cross section perpendicular thereto (xz cross section), it is desirable to satisfy conditional expression (2) in each cross section. 0.00<|φ1 / φ2|≦0.40 (2)

[0034] If conditional expression (2) is not satisfied, the deviation of the incident position of the chief ray on the second reflecting surface 103 becomes large before and after the movement of the first reflecting surface 102. This makes it necessary to increase the size of the second reflecting surface 103, which makes it difficult to make the entire device compact.

[0035] Furthermore, it is preferable to satisfy the following conditional expression (2a), and it is more preferable to satisfy the following conditional expression (2b). 0.03≦|φ1 / φ2|≦0.35 (2a) 0.05≦|φ1 / φ2|≦0.30 (2b)

[0036] FIG. 3 is a schematic diagram (YZ cross-sectional view) of a virtual image display device 100 according to a modified example of the embodiment described above. Similarly to FIG. 2, FIG. 3 also shows a case where the position of the virtual image 113 visually recognized by the user is on the far side (second position). This modified example differs from the embodiment described above in that the virtual image 113 can be decentered with respect to a line (reference axis 111) connecting the center of the pupil 112 and the center of the virtual image 113 by rotating the first reflecting surface 102. The virtual image display device 100 according to this modified example includes a third driving means 108 (rotation mechanism) as a driving means for rotating the first reflecting surface 102.

[0037] According to this configuration, the virtual image 113 can be made non-perpendicular to the reference axis 111, and since the virtual image 113 is well superimposed on the external world when the user is looking into the distance in the second state, it is possible to improve the visibility of the virtual image 113. In this case, in order to reduce the deviation of the incident position of the chief ray on the first reflecting surface 102 before and after the rotation of the first reflecting surface 102, it is desirable that the center of rotation of the first reflecting surface 102 is located on the optical path of the chief ray incident on the first reflecting surface 102. Note that it is desirable that the second reflecting surface 103 is configured so that the relative position between the pupil 112 and the user's eye 104 can be adjusted before and after the rotation of the first reflecting surface 102.

[0038] When the virtual image display device 100 according to this modification is in the first state, it is desirable to make the virtual image 113 perpendicular to the reference axis 111. This allows the virtual image 113 to be well superimposed on the outside world when the user is directing his or her gaze nearby in the first state, thereby improving the visibility of the virtual image 113. However, the virtual image 113 may be made non-perpendicular to the reference axis 111 even in the first state as necessary.

[0039] Furthermore, the image information displayed on the display surface of the display means 101 may be different between the first state and the second state. For example, by changing the shape or position of the image when switching between the first and second states, it is possible to suppress image distortion or center position shift that occurs when switching between the first and second states. This reduces the sense of discomfort felt by the user when switching between the first and second states. In particular, when forming multiple virtual images with different inclinations relative to the reference axis as in this embodiment, it is preferable to make the image information different between the first state and the second state.

[0040] Note that the user in the first state and the user in the second state are not necessarily the same person. For example, if there are multiple users with different sitting heights, the first state and the second state may be switched by moving the first reflecting surface 102 as the users change. If the relative position between the pupil on the magnifying side of the virtual image optical system 105 and the user's eye 104 shifts due to a change in user, a change in the user's posture, vibration of the moving device, or the like, the second reflecting surface 103 may be rotated to correct the shift. Specifically, the relative position between the pupil 112 and the user's eye 104 may be adjusted by rotating the second reflecting surface 103 using the second driving means 107.

[0041] [Example 1] Hereinafter, a virtual image display device 10 according to Example 1 of the present invention will be described. In the virtual image display device 10 according to this example, the description of the same configuration as that of the virtual image display device 100 according to the above-described embodiment will be omitted.

[0042] 4 and 5 are schematic diagrams of the main part of the virtual image display device 10 according to this embodiment. Fig. 4(a) shows the optical path of light from the virtual image display device 10 through the windshield WS to the pupil 112 in a first state, and the virtual optical path when the light from the virtual image display device 10 forms the virtual image 113. Fig. 4(b) shows the optical path of light from the virtual image display device 10 through the windshield WS to the pupil 112 in a second state, and the virtual optical path when the light from the virtual image display device 10 forms the virtual image 113. Fig. 5 is an enlarged view of the optical path near the virtual image optical system in each of the first and second states.

[0043] The virtual image optical system 105 according to this embodiment is composed of a first reflective optical element (first mirror) M11 having a first reflective surface 102 and a second reflective optical element (second mirror) M12 having a second reflective surface 103. The virtual image display device 10 according to this embodiment can change the optical path length from the display surface to the second reflective surface 103 by moving the first reflective optical element M11, thereby changing the position of the virtual image 113 that is viewed by the user. Furthermore, the virtual image display device 10 can change the position of the pupil 112 by rotating the second reflective optical element M12, thereby adjusting the relative position between the pupil 112 and the user's eye 104, which has shifted due to the movement of the first reflective optical element M11.

[0044] [Example 2] Second Embodiment A virtual image display device 20 according to a second embodiment of the present invention will be described below. In the virtual image display device 20 according to this embodiment, the description of the same configuration as that of the virtual image display device 100 according to the above-described embodiment will be omitted.

[0045] 6 and 7 are schematic diagrams of the main part of the virtual image display device 20 according to this embodiment. Fig. 6(a) shows the optical path of light from the virtual image display device 20 through the windshield WS to the pupil 112 in a first state, and the virtual optical path when the light from the virtual image display device 20 forms the virtual image 113. Fig. 6(b) shows the optical path of light from the virtual image display device 20 through the windshield WS to the pupil 112 in a second state, and the virtual optical path when the light from the virtual image display device 20 forms the virtual image 113. Fig. 7 is an enlarged view of the optical path near the virtual image optical system in each of the first and second states.

[0046] The virtual image optical system 105 according to this embodiment is composed of a first reflective optical element (first mirror) M21 having a first reflective surface 102 and a second reflective optical element (second mirror) M22 having a second reflective surface 103. Similar to the virtual image display device 10 according to Example 1, the virtual image display device 20 according to this embodiment can change the optical path length from the display surface to the second reflective surface 103 by moving the first reflective optical element M21, and can change the position of the pupil 112 by rotating the second reflective optical element M22. Furthermore, the virtual image display device 20 can decenter the virtual image by rotating the first reflective optical element M21.

[0047] [Numerical Example] Numerical data for Numerical Examples 1 and 2 corresponding to the above-described Examples 1 and 2 are shown below. In each of the numerical examples, the surface number indicates the surface number i counted from the reduction side, and R indicates the radius of curvature [mm] of the ith surface (i-th surface).

[0048] The virtual image optical system 105 according to each embodiment is an off-axial optical system. The optical axis (reference axis) of the virtual image optical system 105 differs between the first and second states. Therefore, in order to express the position and decentering angle of each surface, an absolute coordinate system XYZ is defined, with the origin at the center of each of the first and second pupils. Specifically, the normal at the origin is defined as the Z axis, and the direction from the object surface toward the image side is defined as the positive (+Z direction). The axis that passes through the origin and forms a 90° counterclockwise angle with the Z axis according to the definition of the right-handed coordinate system is defined as the Y axis. The axis that passes through the origin and is perpendicular to the Z and Y axes is defined as the X axis, and the direction toward the back of the paper in each figure is defined as the positive (+X direction).

[0049] In each numerical example, the sign of the radius of curvature R of the reflecting surface is positive if the reflecting surface is concave toward the reduction side (-Z side) in the absolute coordinate system, and negative if the reflecting surface is convex. Also, Y and Z [mm] in each numerical example represent the coordinates of the vertex of each surface in the Y and Z directions in the absolute coordinate system. θ [degrees] represents the tilt (eccentricity angle) of the normal to the vertex of each surface when the counterclockwise rotation direction with respect to the X axis is positive.

[0050] Next, to express the shape of each surface, a local coordinate system xyz is defined, with the intersection of each surface and the Z axis (reference axis) as its origin. Specifically, the normal at the origin is defined as the z axis. The axis that passes through the origin and forms a 90° counterclockwise angle with the z axis according to the definition of the right-handed coordinate system is defined as the y axis. The axis that passes through the origin and is perpendicular to the z and y axes is defined as the x axis, and the direction into the paper in Figure 1 is defined as the positive (+x direction). Here, the shape of the aspherical surface is defined by the conic constant K and the aspherical coefficient C ij , where R is the paraxial radius of curvature, it is expressed by the following equation. Note that the conic constant K and the aspherical coefficient C in each numerical example are ij "E±N" for each value is "×10 ±N " means.

[0051]

number

[0052] However, h is expressed by the following formula.

[0053]

number

[0054] (Numerical Example 1) Surface Data Surface number RYZ θ 1 101 ∞ 0.00 0.00 -42.7 2 M11 ∞ Variable Variable -20.0 3 M12 ∞ 0.00 179.00 Variable 4 WS ∞ 147.84 2.81 73.0 5 112 ∞ 196.55 349.40 138.0 6 113 ∞ Variable Variable 138.0 Variable Amount Data First state Second state Y M11 12.93 0.00 Z M11 151.97 179.00 θ M12 -17.7 -16.0 Y Virtual image 1668.64 6352.55 Z virtual image -1285.52 -6487.53 Aspheric data M11 M12 K 0.00E+00 0.00E+00 C20 1.90E-04 6.72E-04 C02 -7.67E-05 5.16E-04 C21 -5.78E-06 -8.07E-07 C03 -4.82E-06 -6.94E-07 C40 2.83E-09 1.46E-10 C22 2.51E-08 7.67E-10 C04 1.15E-08 -2.77E-10

[0055] (Numerical Example 2) Surface Data Surface number RYZ θ 1 101 ∞ 0.00 0.00 -42.7 2 M11 ∞ Variable Variable Variable 3 M12 ∞ 147.84 2.81 Variable 4 WS ∞ 196.55 349.40 73.0 5 112 ∞ -338.75 943.92 138.0 6 113 ∞ Variable Variable Variable Variable Amount Data First state Second state Y M21 20.00 7.85 Z M21 143.27 190.52 θ M21 -20.00 -22.03 θ M22 -19.20 -16.00 Y Virtual image 1334.07 9698.21 Z Virtual Image -913.94 -10203.25 θ Virtual image 0.00 85.00 Aspheric data M21 M22 K 0.00E+00 0.00E+00 C20 -8.25E-05 6.29E-04 C02 -4.04E-05 5.33E-04 C21 -3.84E-06 -6.09E-07 C03 -2.33E-06 -3.63E-07 C40 2.36E-09 2.31E-10 C22 1.83E-08 1.99E-09 C04 -1.30E-09 -1.47E-10

[0056] Numerical values ​​relating to the above-mentioned conditional expressions in Numerical Examples 1 and 2 are shown below.

[0057] [Table 1]

[0058] [In-vehicle systems and mobile devices] 8 is a schematic diagram of an in-vehicle system 500 and a moving device 600 equipped with the virtual image display device 100 according to this embodiment. The in-vehicle system 500 is a system that includes the virtual image display device 100, a first acquisition means 200, a second acquisition means 300, and a control means 400, and is for supporting a user (passenger, driver) of the moving device 600. The moving device 600 is a moving body that can move while holding the in-vehicle system 500, such as an automobile, a ship, or an airplane, as described above. In FIG. 8, an automobile (vehicle) is shown as an example of the moving device 600.

[0059] The first acquisition means 200 is a means for acquiring at least one of the user's position information and viewpoint information, and is, for example, an imaging device such as a camera. The user's position information is information relating to the position of at least a part of the user, for example, information relating to the position of the user's eye 104. The user's viewpoint information is information relating to the user's viewpoint or line of sight, for example, information relating to the movement of the user's eye 104 (pupil).

[0060] The second acquisition means 300 is a means for acquiring external information (peripheral information) such as obstacles (pedestrians, other vehicles, etc.) and the surrounding environment (scenery) around the mobile device 600, and is, for example, an imaging device such as a camera. The second acquisition means 300 according to this embodiment is arranged to acquire external information in front of the mobile device 600, but may also be arranged to acquire external information behind or to the sides of the mobile device 600.

[0061] The control means 400 is a means for controlling the virtual image display device 100, and is, for example, a processor such as a CPU. The control means 400 can control the display of an image by the display means 101 in the virtual image display device 100, and can control the driving of the reflective surfaces by the driving means. For example, the control means 400 can control the display of an image by the display means 101 and the driving of each reflective surface by the driving means, based on at least one of the information acquired by the first acquisition means 200 and the information acquired by the second acquisition means 300. The control means 400 may be provided inside the virtual image display device 100. Furthermore, the function of the control means 400 may be provided to the driving means, as described above.

[0062] The first acquisition means 200 acquires at least one of the user's position information and viewpoint information, thereby detecting the amount of deviation in the position of the user's eye 104 relative to the moving device 600 and changes in the user's line of sight. The control means 400 calculates the drive amount of each reflective surface in the virtual image display device 100 based on the information acquired by the first acquisition means 200, and drives each reflective surface by controlling the drive means based on the drive amount. This makes it possible to change the position of the virtual image 113 and correct the deviation in the relative position between the user's eye 104 and pupil 112.

[0063] Furthermore, the control means 400 may change the position of the virtual image 113 that is viewed by the user by controlling the driving of each reflective surface based on information (speed information) related to the moving speed of the moving device 600. For example, by setting the position of the virtual image 113 to a first position when the moving device 600 is moving at a low speed or stopped (speed 0) and to a second position when the moving device 600 is moving at a high speed, it is possible to switch between displaying a virtual image 113 that appears close and displaying a virtual image 113 that appears far away. This allows the user to visually recognize that the position of the virtual image in the traveling direction of the moving device 600 has switched, thereby improving the visibility of each virtual image when the speed of the moving device 600 changes.

[0064] The control means 400 may control the driving of each reflecting surface by the driving means based on a signal output from an operating means (not shown) when the user operates the operating means. Furthermore, even if the first acquisition means 200 acquires information about a position other than the user's eye 104, the control means 400 can calculate the amount of deviation of the position of the user's eye 104 relative to the moving device 600 based on the information.

[0065] The control means 400 also has a function as a determination means for determining the possibility of collision with an obstacle (object). For example, the control means 400 determines the possibility of collision between the moving device 600 and an obstacle based on the external world information acquired by the second acquisition means 300. When the control means 400 determines that there is a possibility of collision with an obstacle, it can warn the user by, for example, displaying a warning message on the virtual image display device 100.

[0066] When the control means 400 determines that there is a possibility of collision with an obstacle, it may control the movement of the mobile device 600 or cause each part of the mobile device 600 to issue a warning. For example, the control means 400 can control the movement of the mobile device 600 by outputting a control signal to a drive unit (such as an engine or motor) of the mobile device 600. Examples of control methods include applying the brakes on the mobile device 600, releasing the accelerator, turning the steering wheel, or generating a control signal to generate a braking force on each wheel to suppress the output of the drive unit. Examples of warning methods include issuing a warning sound to the user, displaying warning information on the screen of a car navigation system or the like, or vibrating the seat belt or steering wheel.

[0067] Although the preferred embodiments and examples of the present invention have been described above, the present invention is not limited to these embodiments and examples, and various combinations, modifications, and changes are possible within the scope of the gist of the present invention.

[0068] For example, although the in-vehicle system 500 according to the above-described embodiment includes one each of the first acquisition unit 200 and the second acquisition unit 300, it may include a plurality of each. Alternatively, a single acquisition unit having the functions of both the first acquisition unit 200 and the second acquisition unit 300 may be employed. Furthermore, instead of the first acquisition unit 200 and the second acquisition unit 300, a unit for detecting vibrations, acceleration, etc. of the moving device 600 may be provided, and the virtual image display device 100 may be controlled based on information acquired by that unit. [Explanation of symbols]

[0069] 101 Display means (display surface) 102 First Reflecting Surface 103 Second Reflective Surface 105 Virtual Image Optical System 112 Hitomi 113 Virtual Image

Claims

1. A virtual image optical system that forms a virtual image by guiding light from a display surface to a pupil, a first reflecting surface that reflects light from the display surface; a second reflecting surface that reflects light from the first reflecting surface; The optical path length from the display surface to the second reflecting surface can be changed by moving the first reflecting surface, the virtual image can be decentered with respect to a line connecting the center of the pupil and the center of the virtual image by rotating the first reflecting surface; the position of the pupil can be changed in a direction including a component perpendicular to an optical path of a chief ray incident on the pupil by rotating the second reflecting surface, 10. A virtual image optical system, wherein an angle formed between a direction of movement of said first reflecting surface and a chief ray incident on said first reflecting surface is 5 degrees or less.

2. When the sum of the angle of incidence and the angle of reflection of the chief ray on the first reflecting surface is β, ３０°≦β≦７０° 2. The virtual image optical system according to claim 1, wherein the following condition is satisfied:

3. On the optical path of the principal ray, when the power of the first reflecting surface is φ1 and the power of the second reflecting surface is φ2, 0.00<|φ1 / φ2|≦0.40 3. The virtual image optical system according to claim 1, wherein the following condition is satisfied:

4. 4. The virtual image optical system according to claim 1, wherein the center of rotation of the second reflecting surface is located between the position of incidence of the chief ray on the second reflecting surface when the first reflecting surface is at its most reduction side and the position of incidence of the chief ray on the second reflecting surface when the first reflecting surface is at its most enlargement side.

5. 5. The virtual image optical system according to claim 1, wherein the center of rotation of the first reflecting surface is located on the optical path of the chief ray incident on the first reflecting surface.

6. The virtual image optical system according to any one of claims 1 to 5, a display means having the display surface; a first driving means for driving the first reflecting surface and a second driving means for driving the second reflecting surface, respectively;

7. 7. The virtual image display device according to claim 6, wherein the first driving means is capable of changing the position of the virtual image visually recognized by the user by moving the first reflecting surface.

8. 8. The virtual image display device according to claim 6, wherein the second driving means is capable of adjusting the relative position between the pupil and the user's eye by rotating the second reflecting surface.

9. 9. The virtual image display device according to claim 6, wherein at least one of the first and second driving means drives at least one of the first and second reflecting surfaces based on at least one of position information and viewpoint information of a user.

10. An in-vehicle system comprising the virtual image display device according to any one of claims 6 to 9, and held by a vehicle.

11. The in-vehicle system according to claim 10, further comprising a first acquisition means for acquiring at least one of a user's position information and viewpoint information, and at least one of the first and second driving means for driving at least one of the first and second reflecting surfaces based on the information acquired by the first acquisition means.

12. 12. The in-vehicle system according to claim 10, wherein at least one of the first and second driving means drives at least one of the first and second reflecting surfaces based on information relating to the moving speed of the vehicle.

13. 13. The in-vehicle system according to claim 10, further comprising a second acquisition unit for acquiring external information.

14. 14. The in-vehicle system according to claim 13, further comprising a determination unit that determines a possibility of a collision between the vehicle and an object based on the information acquired by the second acquisition unit.

15. 15. The in-vehicle system according to claim 14, wherein when the determining means determines that there is a possibility of a collision between the vehicle and the object, the virtual image display device issues a warning to a user.

16. A moving device comprising the virtual image display device according to any one of claims 6 to 9, and capable of holding and moving the virtual image display device.

17. 17. The moving device according to claim 16, further comprising an optical member that reflects light from the virtual image display device toward a user.

18. 18. The moving device according to claim 17, wherein the optical member transmits light from the outside toward the user.

Images