JP2011128500A - Lens optical system, image display device and head-up display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens optical system, capable of downsizing an image display device such as a head-up display, and also to provide the image display device and the head-up display, each using the lens optical system. <P>SOLUTION: The lens optical system includes in order from an object side: a first convex lens group 20 wherein a plurality of first-element convex lenses 21 are arranged planarly; a second convex lens group 22 wherein a plurality of second-element convex lenses 23 are arranged planarly; and a third convex lens group 24 wherein a plurality of third-element convex lenses 25 are arranged planarly. The lens optical system is configured so that the lens diameter and lens pitch in each of the element convex lenses become larger in order of the first, second and third convex lens groups 20, 22 and 24. The optical path of light emitted from the third convex lens group is changed by a convex mirror. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a lens optical system, and an image display device and a head-up display using the lens optical system.

  2. Description of the Related Art Conventionally, a head-up display that displays information such as a vehicle speed in front of a front window of a vehicle is known. The driver can check information such as the vehicle speed without much moving the line of sight while driving the vehicle by superimposing the display image displayed by the head-up display and the scenery in front of the vehicle.

  FIG. 1 shows an example of a conventional head-up display. This head-up display is disclosed in Patent Document 1. As shown in FIG. 1, the optical unit 80 arranged on the dashboard of the car includes a display 88 that is an image display unit, a plane mirror 81, and a concave mirror 82. The light from the display 88 is reflected by the plane mirror 81 and the concave mirror 82 that is a magnifying optical system, passes through the exit window 87, and is reflected toward the driver by the combiner 102 provided on the front window 101. For the driver, the displayed virtual image 103 is visually recognized in front.

  The role of the plane mirror 81 is to bend the optical path when the optical path from the display 88 to the concave mirror 82 cannot be made straight due to the spatial restriction of the optical unit 80.

FIG. 2 is an explanatory view of the far-increasing display by the concave mirror 82. The distance between the display 88 and the concave mirror 82 (center point is Q) is L ₁ , the distance of QP ′ when the virtual image of the concave mirror at the point P on the display is P ′ is L ₂ , the point Q and the combiner 102 The distance between the center point R is L ₃ and the distance between the point R and the driver's eye position (point E) is L ₄ .

The distance between the driver's eye position (point E) and the virtual image P ″ formed forward is L ₂ + L ₃ + L _4. Of these, L ₃ and L ₄ are determined by the car, and in the case of a passenger car, is about 1 m. Therefore, as can view the display and view outside the vehicle without focus movement of the eye, in order to display more virtual image far away, it is necessary to increase the L _2.

One method of increasing the L ₂ is an optical path length L1 extending from the focal length shorter (smaller radius of curvature) to display 88 of the concave mirror 82 to the concave mirror 82 in a short state than the focal length of the concave mirror, as much as possible It is close to the focal length. Thereby, a large enlargement magnification can be obtained, and the display 88 can be small.

Alternatively, (large curvature radius) long focal length using a concave mirror 82, there is a long take ways L _1. With this method, the display distance can be increased even with a low magnification. For example, like the optical unit shown in FIG. 3, plane mirrors 91 and 92 and a concave mirror 93 are provided so that optical paths overlap in a limited space. As a result, the optical unit is miniaturized.

  In the above description, the concave mirror 82 is used to form a virtual image of the image displayed on the display 88 and at the same time to enlarge and display the virtual image. Since the dashboard of a car needs a device other than the head-up display, it is desired that the optical system of the head-up display is as small as possible. Therefore, a small display is used. However, since it is necessary for the driver to display a virtual image of a certain size, the concave mirror 82 is required as an optical system for enlarging the image.

  In addition, the front window of a car is often a curved surface due to restrictions on the design of the vehicle, which causes distortion in the image reflected by the front window. For this reason, as shown in FIG. 4, the concave mirror 82 is also provided with a function for correcting this distortion. FIG. 4 is disclosed in Patent Document 2.

Japanese Patent Laid-Open No. 06-55957 JP 2004-98834 A

However, in the conventional head-up display optical unit of Figure 1, in order to display a virtual image (display image) more distant, without lengthening the optical path length L ₁ of the optical system, increasing the magnification of the optical system, Although the display image can be displayed farther without enlarging the optical unit, there is a problem that the display image has a large distortion and aberration, and the image flows when the viewpoint is changed.

  In addition, in the conventional head-up display shown in FIGS. 1 to 4, a concave mirror is installed in the optical unit to form a virtual image and display an enlarged image at the same time, but sunlight transmitted through an opening such as a front window is concave mirror. Since the light reflected by the concave mirror is collected when it is incident on the head, there is a problem that there is a possibility of damaging a device such as a display, particularly a display in the head-up.

  In addition, the concave mirror has both the function of forming a virtual image and a magnifying optical system, and the function of correcting the distortion of the reflected image due to the curved surface of the front window. There was a problem that the degree of freedom was small and it was difficult to make the functions compatible with each other and it was difficult to add other functions. For this reason, there is a problem that the optical system cannot be made small because it is necessary to separately install optical components having respective functions.

  The present invention has been made in view of such a situation, and an object of the present invention is to reduce the size of an image display device such as a head-up display and to prevent damage due to sunlight, and the lens optical system. An object of the present invention is to provide an image display device and a head-up display using the above.

  In order to solve the above problems, in a lens optical system according to an aspect of the present invention, a first convex lens group in which a plurality of convex lenses are arranged in a planar shape and a plurality of convex lenses are arranged in a planar shape in order from the object side. A second convex lens group, and a third convex lens group in which a plurality of convex lenses are arranged in a planar shape. The first convex lens group, the second convex lens group, and the third convex lens group are configured in order of the lens diameter and lens pitch of the convex lens.

  According to this aspect, each convex lens of the first convex lens group that has received the light emitted radially from the object forms an inverted image of the object at the imaging point of each convex lens. Each convex lens of the second convex lens group receives the light flux of each inverted image and bends it in the optical axis direction of each convex lens. Each convex lens of the third convex lens group receives each bent light beam and forms a virtual image of the object farther than the optical path length from the viewpoint to the object. A virtual image can be formed at an arbitrary position by adjusting the lens pitch and the radius of curvature of the convex lens of the third convex lens group. According to this aspect, a virtual image of an object can be formed at an arbitrary position without increasing the optical path length of the optical system as in the conventional technique described above. Can be

  Another aspect of the present invention is an image display device. The apparatus includes an image display unit that displays an image, the above-described lens optical system that receives light from the image display unit and displays a virtual image of the image, and a convex mirror that changes an optical path of emitted light of the lens optical system. .

  According to this aspect, a small image display device can be configured. Such an image display device can be used for a game machine, for example. In other words, a three-dimensional effect of the game can be produced by forming a virtual image having a depth farther than the image displayed on the image display unit.

  Further, since the formation and enlargement of the virtual image and the correction of distortion due to the curved front window can be divided into the lens optical system and the convex mirror, the convex mirror can have other functions. By displaying the image compressed in one direction on the image display unit and restoring the image even if the image is expanded with a convex mirror, the thickness of the image display unit and the optical system can be reduced. The image display device can be downsized.

  Yet another embodiment of the present invention is a head-up display. This head-up display includes an image display unit that displays an image, a lens optical system that receives light from the image display unit, a convex mirror that changes the optical path of light emitted from the lens optical system, and a light path that is reflected toward an observer. And a combiner that displays a virtual image of the image in front of the observer.

  According to this aspect, the optical unit in the head-up display can be reduced in size. This makes it possible to store the optical unit of the head-up display even when there is not enough space in the dashboard.

  In addition, the mirror that changes the optical path of the light emitted from the lens optical system is a convex mirror, and the sunlight incident from the front window diverges without condensing. It is possible to prevent the display portion from being damaged.

  It should be noted that any combination of the above-described constituent elements and a representation obtained by converting the expression of the present invention between a method, an apparatus, a system, and the like are also effective as an aspect of the present invention.

  According to the present invention, it is possible to provide a lens optical system that can downsize an image display device such as a head-up display, and an image display device and a head-up display using the lens optical system. Furthermore, since the mirror for changing the optical path can have a convex shape with respect to the lens optical system, when sunlight incident from an opening such as a front window enters the image display device or the head-up display, the sunlight is mirrored. It is possible to prevent a problem that parts such as the image display unit are damaged by condensing light.

It is a figure which shows an example of the conventional head-up display. It is a figure which shows explanatory drawing of the distant expansion display by a concave mirror. It is a figure which shows an example of another conventional optical unit. It is a figure which shows an example of another conventional optical unit. It is a figure for demonstrating the lens optical system which concerns on embodiment of this invention. It is sectional drawing of the lens optical system which concerns on this Embodiment. FIGS. 7A to 7C are diagrams for explaining the operation of the lens optical system according to the present embodiment. It is a figure for demonstrating the head-up display using the lens optical system which concerns on this Embodiment. It is a figure explaining the effect of the concave mirror which concerns on this Embodiment. It is a figure for demonstrating the head-up display which concerns on other embodiment of this invention. It is a figure for demonstrating the head-up display which concerns on other embodiment of this invention.

  10 lens optical system, 12 first lens array plate, 14 second lens array plate, 20 first convex lens group, 21 first element convex lens, 22 second convex lens group, 23 second element convex lens, 24 third convex lens group, 25 Third element convex lens, 30 image display unit, 32 front window, 34 combiner, 40 object, 42 virtual image, 52 image, 54 virtual image, 100 head-up display.

  FIG. 5 is a diagram for explaining the lens optical system 10 according to the embodiment of the present invention. As shown in FIG. 5, the lens optical system 10 has a structure in which a first lens array plate 12 and a second lens array plate 14 in which a plurality of convex lenses are formed on both surfaces are laminated. FIG. 5 shows a state in which a plurality of second outer convex lenses 14 a are arranged on the second outer surface 14 c of the second lens array plate 14.

  The lens optical system 10 receives light from the object 40 located on the object side which is the first outer surface 12c side of the first lens array plate 12, and is on the second outer surface 14c side of the second lens array plate 14. The virtual image 42 is displayed on the observer 44 located on the observation side. The virtual image 42 is formed farther than the optical path length from the viewpoint of the observer 44 to the object 40. By using the lens optical system 10 according to the present embodiment, an image display device that displays a virtual image to an observer, such as a head-up display, can be configured.

  FIG. 6 is a cross-sectional view of the lens optical system 10 according to the present embodiment. As described above, the lens optical system 10 has a structure in which the first lens array plate 12 having a plurality of convex lenses arranged on both surfaces and the second lens array plate 14 are laminated. That is, a plurality of first outer convex lenses 12a are regularly arranged on the first outer surface 12c which is one surface of the first lens array plate 12, and on the first inner surface 12d which is the other surface. The plurality of first inner convex lenses 12b are regularly arranged. A plurality of second outer convex lenses 14a are regularly arranged on the second outer surface 14c, which is one surface of the second lens array plate 14, and on the second inner surface 14d, which is the other surface. A plurality of second inner convex lenses 14b are regularly arranged. The first lens array plate 12 and the second lens array plate 14 are laminated so that the first inner convex lens 12b and the second inner convex lens 14b face each other.

  On the first outer surface 12c, the first inner surface 12d, the second outer surface 14c, and the second inner surface 14d, the first outer convex lens 12a, the first inner convex lens 12b, the second outer convex lens 14a, and the second inner convex lens 14b are , Each arranged in a close packed arrangement. FIG. 5 shows a state in which the second outer convex lenses 14 a are arranged in a close-packed arrangement on the second outer surface 14 c of the second lens array plate 14.

  In the present embodiment, the plurality of first outer convex lenses 12 a arranged in a plane form a first convex lens group 20. Hereinafter, the first outer convex lens 12a is appropriately referred to as a “first element convex lens 21”.

  Further, the first inner convex lens 12b and the second inner convex lens 14b arranged in a planar shape have the same lens diameter and lens pitch, and the first inner convex lens 12b and the second inner convex lens 14b facing each other have a single optical axis. In addition, the surfaces of the convex lenses are arranged so as to contact each other. One set of the first inner convex lens 12b and the second inner convex lens 14b arranged in this manner functions as one convex lens. Therefore, in the following, a pair of the first inner convex lens 12b and the second inner convex lens 14b facing each other is appropriately treated as the “second element convex lens 23”. The plurality of second element convex lenses 23 constitute a second convex lens group 22.

  The plurality of second outer convex lenses 14 a arranged in a plane form a third convex lens group 24. Hereinafter, the second outer convex lens 14a is appropriately referred to as a “third element convex lens 25”.

In the present embodiment, the first convex lens group 20, the second convex lens group 22, and the third convex lens group 24 are configured so that the lens diameter and lens pitch of the convex lens increase in this order. That is, the lens diameter d ₁ of the first element convex lens 21 <the lens diameter d ₂ of the second element convex lens 23 <the lens diameter d ₃ of the third element convex lens 25, and the lens pitch p ₁ of the first element convex lens 21 <second. The lens pitch p ₂ of the element convex lens 23 is smaller than the lens pitch p ₃ of the third element convex lens 25. In the present embodiment, the lens pitch is the distance between the centers of the two closest lenses. The lens diameter is a diameter of a portion having a function as a lens.

  Further, in the present embodiment, the second convex lens group 22 is arranged such that its main plane is located on the image plane of the first convex lens group 20. The main plane of the second convex lens group 22 is a plane on which the contact point between the first inner convex lens 12b and the second inner convex lens 14b in each second element convex lens 23 is located. The imaging plane of the first convex lens group 20 is a plane on which the imaging point of each first element convex lens 21 is located. As will be described later, by arranging the second convex lens group 22 at such a position, the light beam from the object can be favorably bent, and a virtual image can be formed farther than the object. The position of the third convex lens group 24 with respect to the first convex lens group 20 is set according to the distance from the object to the first convex lens group 20, as will be described later.

  The first lens array plate 12 and the second lens array plate 14 are formed by injection molding. The material of the first lens array plate 12 and the second lens array plate 14 is preferably one that can be used for injection molding, has high light transmittance with respect to light in a necessary wavelength band, and low water absorption. Examples of desirable materials include cycloolefin resins, olefin resins, norbornene resins, and polycarbonates.

  FIGS. 7A to 7C are diagrams for explaining the operation of the lens optical system 10 according to the present embodiment. FIG. 7A shows that when the object “F” is observed with both eyes from a position separated by the distance D, the observer can confirm the object at the position of the distance D.

  Here, as shown in FIG. 7B, the first convex lens group 20 and the third convex lens group 24 having different lens diameters and lens pitches are arranged at a desired interval between the object and the observer's viewpoint, and the object Are divided into luminous fluxes emitted from the first element convex lenses 21 of the first convex lens group 20. Here, the distance between the first convex lens group 20 and the third convex lens group 24 is such that the light beam radiated from the object is emitted from the third convex lens group 24 without any change in angle, and the first convex lens group 20 is individually separated from the object. It is determined so as to match the light ray angle (radiation angle) stretched on the one-element convex lens 21.

  In the case of the configuration as shown in FIG. 7B, each first element convex lens 21 of the first convex lens group 20 that has received light emitted radially from the object is an inverted image at the imaging point of each first element convex lens 21. (Also referred to as an elemental image). Each third element convex lens 25 of the third convex lens group 24 receives each light flux of each element image and emits it toward the observer. When the observer observes such a radiation beam with both eyes, the object can be visually recognized by inverting the position of the distance D from the viewpoint of the observer.

  Next, as shown in FIG. 7C, the lens diameter and the lens pitch are larger between the first convex lens group 20 and the third convex lens group 24 than the first convex lens group 20, and the lens diameter and the lens pitch are larger than those of the third convex lens group 24. A second convex lens group 22 having a small lens pitch and a larger refractive power than the first convex lens group 20 and the third convex lens group 24 is added. As described above, the second convex lens group 22 is arranged such that its main plane is located on the image plane of the first convex lens group 20.

  Each second element convex lens 23 of the second convex lens group 22 bends each light flux contributing to the image formation of each element image in the optical axis direction of each second element convex lens 23. As described above, the light beam is bent by the second element convex lenses 23 of the second convex lens group 22, so that the observer can visually recognize the observation image which is a virtual image on the extension line in the opposite direction from the viewpoint of the bent light beam. By adjusting the lens pitch of the third convex lens group 24 and the radius of curvature of the third element convex lens 25, an observation image can be formed at an arbitrary position D '. Of course, the magnification of the observation image can be changed by changing the distance E between the object and the first convex lens group 20.

  That is, the first convex lens group 20 forms a high-quality inverted image, and the lens pitch and the radius of curvature of the third convex lens group 24 and the positions of the second convex lens group 22 and the third convex lens group 24 are adjusted. By reading out the image, a virtual image can be formed at an arbitrary position, and both parallax and diopter can be achieved.

  Thus, according to the lens optical system 10 according to the present embodiment, a virtual image of an object can be formed at an arbitrary position without increasing the distance E between the object and the first convex lens group 20. In addition, an image display device such as a head-up display can be downsized.

  FIG. 8 is a diagram for explaining a head-up display 100 using the lens optical system 10 according to the present embodiment. The head-up display 100 includes an image display unit 30, the above-described lens optical system 10, a convex mirror 33 that changes the optical path of light emitted from the optical system, and a combiner 34. The lens optical system 10, the image display unit 30, and the convex mirror 33 constitute an optical unit of the head-up display 100, and are accommodated in, for example, a dashboard of a vehicle.

  The image display unit 30 is composed of, for example, a liquid crystal display, and displays information such as the vehicle speed and the remaining fuel amount as an image 52 based on a signal from an image processing unit (not shown).

  The lens optical system 10 is disposed so that the first outer surface 12 c of the first lens array plate 12 faces the surface of the image display unit 30. The light emitted from the image display unit 30 enters the first convex lens group 20, then passes through the second convex lens group 22 and is emitted from the third convex lens group 24.

  A convex mirror 33 is disposed so that the light beam emitted from the lens optical system 10 enters the front window 32 at a predetermined incident angle, for example, an incident angle of 45 degrees. In the optical unit of the conventional head-up display of FIG. 1, the mirror that changes the optical path forms a virtual image and becomes a concave mirror to enlarge, whereas in the present invention, the lens optical system 10 displays on the image display unit 30. Since the convex mirror 33 has a function of forming and enlarging a virtual image of the generated image, the convex mirror 33 is only required to correct a reflected image distorted by the curved surface of the front window 32, and thus is a convex mirror.

  The combiner 34 is a reflective film formed on the surface of the front window 32 and reflects the light emitted from the lens optical system 10 toward the driver 50. The driver can visually recognize the virtual image 54 of the image 52 on the extension line of the optical path from the viewpoint to the combiner 34.

  Here, the distance from the image display unit 30 to the first convex lens group 20 of the lens optical system 10 is D1, the distance from the third convex lens group 24 of the lens optical system 10 to the convex mirror 33 is D2, and the distance from the convex mirror 33 to the combiner 34 is The distance is D3, the distance from the combiner 34 to the viewpoint of the driver 50 is D4, and the distance from the combiner 34 to the virtual image 54 is D5. At this time, the optical path length from the viewpoint of the driver 50 to the image 52 is D1 + D2 + D3 + D4. Further, the optical path length from the viewpoint of the driver 50 to the virtual image 54 is D4 + D5. In the lens optical system 10 according to the present embodiment, the optical path length D4 + D5 from the viewpoint of the driver 50 to the virtual image 54 and the optical path length D1 + D2 + D3 + D4 from the viewpoint of the driver 50 to the image 52 are the same as described in FIG. Can be longer.

  The virtual image 54 is preferably formed as far as possible in front of the vehicle so that the driver 50 can visually recognize the scenery in front of the vehicle and the virtual image 54 superimposed on each other. For example, it is desirable to secure a distance D5 from the combiner 34 to the virtual image 54 of about 1 m. In the optical unit of the conventional head-up display as shown in FIG. 3, in order to secure 1 m from the combiner to the virtual image, it is necessary to secure 1 m of the optical path length from the image to the concave mirror. In this case, it is difficult to reduce the size of the optical unit. However, the distance D1 + D2 + D3 can be made smaller than the distance D4 by configuring the head-up display 100 using the lens optical system 10 according to the present embodiment. Therefore, it is not necessary to secure a very long optical path length in the optical unit, and the optical unit can be downsized.

  In addition, as shown in FIG. 9A, in the conventional optical unit, the mirror that changes the optical path is a concave mirror, so that the sunlight incident on the optical unit from the front window is condensed by the concave mirror, and the image display unit In contrast, in the optical unit of the present invention, the mirror installed is a convex mirror, so that sunlight incident on the optical unit from the front window is not collected by the mirror as shown in FIG. 9B. Therefore, damage to the image display unit can be prevented.

  Moreover, according to the head-up display 100 according to the present embodiment, the virtual image 54 that is the depth image of the image 52 displayed on the image display unit 30 can be configured with a very simple configuration. As a device for forming an image with a sense of depth, a lenticular screen is conventionally arranged at the image forming position of the video projection system, and images including binocular parallax are spatially separated and presented to the left and right eyes, respectively. An apparatus is disclosed. However, in such an apparatus, the left and right images including the binocular parallax are synthesized in the observer's head to obtain a sense of depth, so that it is not easy to recognize an image with a sense of depth. It will accompany. However, in the head-up display 100 according to the present embodiment, it is not necessary to synthesize the left and right images including binocular parallax in the observer's head, and the virtual image 54 with a sense of depth can be easily visually recognized. Because it can, the observer will not feel tired.

  Next, a head-up display 200 according to another embodiment in which functions other than correction of distortion due to the curved surface of the front window are added to the convex mirror will be described.

  FIG. 10 shows a case where the image displayed on the image display unit 30 is compressed and displayed in the vertical direction of the paper (the height direction of the head-up display) in the optical system shown in FIG. By compressing the image displayed on the image display unit 30 in one direction, particularly in the height direction of the head-up display, the height of the image display unit necessary for display can be reduced. In addition, since the width of the optical system 10 (vertical direction on the paper surface) necessary for forming the virtual image can be reduced in accordance with the image display unit, the height of the optical system can be reduced, and the head-up display can be made thin. can do.

  In FIG. 10, the image compressed in the height direction of the head-up display is expanded in the height direction by the convex mirror 33 and converted into an image having a predetermined aspect ratio. Therefore, the visible virtual image is not a compressed image but an original image before compression.

  Further, the image may be compressed by the image displayed on the image display unit as described above. However, as shown in FIG. 10, the image compression may be performed by installing a cylindrical lens 62 on the emission side of the image display unit 30. Also good. Further, the image may be compressed by both the image display unit 30 and the cylindrical lens 62.

  In order to brighten the virtual image in the head-up display, it is desirable to arrange the cylindrical lens 62 in the immediate vicinity of the image display unit 30 as shown in FIG. By disposing the cylindrical lens 62, it becomes possible to make more light emitted from the image display unit 30 reach the lens optical system 10, and thus the image on the head-up display can be brightened.

The case where the mirror that changes the optical path is the convex mirror 33 has been described above in order to correct the distortion of the image due to the curved surface of the front window. However, as shown in FIG. 11, an image corresponding to the distortion of the image due to the curvature of the front window is processed and displayed on the image display unit, so that the mirror that changes the optical path is not a convex mirror but a plane mirror 36. Can do. By using the plane mirror 36, the mirror can be easily manufactured, and the cost of the head-up display can be reduced. Further, even when a plane mirror is used, sunlight incident from the front window is not collected, so that it is possible to prevent the image display unit from being damaged.

Claims (6)

In order from the object side, a first convex lens group in which a plurality of convex lenses are arranged in a plane, a second convex lens group in which a plurality of convex lenses are arranged in a plane, and a third convex lens in which a plurality of convex lenses are arranged in a plane. A group,
A lens optical system, wherein a lens diameter and a lens pitch of the convex lens increase in order of the first convex lens group, the second convex lens group, and the third convex lens group. An image display unit for displaying an image;
The lens optical system according to claim 1, which receives light from the image display unit and displays a virtual image of the image;
A convex mirror that changes the optical path of the emitted light of the lens optical system;
An image display device comprising: The image display unit for displaying an image compressed in one direction;
The convex mirror bent in the same direction as the compressed direction of the image;
The image display apparatus according to claim 2, further comprising: An image display unit for displaying an image;
The lens optical system according to claim 1, which receives light from the image display unit;
A convex mirror that changes the optical path of the emitted light of the lens optical system;
A combiner that reflects light from the convex mirror toward the viewer and displays a virtual image of the image in front of the viewer;
A head-up display comprising: The image display unit for displaying an image compressed in one direction;
The convex mirror bent in the same direction as the compressed direction of the image;
The head-up display according to claim 4, further comprising: A cylindrical lens that bends light emitted from the image display unit in one direction;
The convex mirror bent in a direction in which the light is bent by the cylindrical lens;
The head-up display according to claim 4, further comprising: