WO2020031654A1 - Dispositif d'affichage d'informations et procédé d'affichage d'informations - Google Patents

Dispositif d'affichage d'informations et procédé d'affichage d'informations Download PDF

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Publication number
WO2020031654A1
WO2020031654A1 PCT/JP2019/028353 JP2019028353W WO2020031654A1 WO 2020031654 A1 WO2020031654 A1 WO 2020031654A1 JP 2019028353 W JP2019028353 W JP 2019028353W WO 2020031654 A1 WO2020031654 A1 WO 2020031654A1
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WIPO (PCT)
Prior art keywords
windshield
virtual image
information display
display device
driver
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PCT/JP2019/028353
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English (en)
Japanese (ja)
Inventor
平田　浩二
谷津　雅彦
長平 小野
昭央 三沢
漢英 郭
杉山　寿紀
康彦 國井
雅千 福井
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マクセル株式会社
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Publication of WO2020031654A1 publication Critical patent/WO2020031654A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K35/00—Instruments specially adapted for vehicles; Arrangement of instruments in or on vehicles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
    • B60R11/00—Arrangements for holding or mounting articles, not otherwise provided for
    • B60R11/02—Arrangements for holding or mounting articles, not otherwise provided for for radio sets, television sets, telephones, or the like; Arrangement of controls thereof
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/01—Head-up displays

Definitions

  • the present invention provides an information display for projecting an image on a windshield (hereinafter, also referred to as a “window glass” or a “wind shield”) of an automobile, a train, an aircraft, or the like (hereinafter, also generally referred to as a "vehicle”). More particularly, the present invention relates to a projection optical system for observing an image as a virtual image through the windshield, and an information display device and an information display method using the same.
  • HUD Head Up Display
  • -Up-Display A so-called HUD (Head Up Display) that projects virtual light onto a windshield or a combiner of an automobile to form a virtual image and display traffic information such as route information and congestion information and automobile information such as a fuel remaining amount and a cooling water temperature.
  • -Up-Display -Up-Display
  • the head-up display device necessarily requires a windshield or a combiner as a final reflection surface for providing a virtual image to a driver.
  • the inventors have proposed a front reflection surface which is a final reflection surface in order to obtain high visibility and good resolution performance. It has been realized that the improvement of the double image of the virtual image caused by the double reflection occurring in the glass or the combiner is important.
  • FIG. 23 The principle of the virtual image generation by the concave mirror realizing the head-up display device according to the prior art is as shown in FIG. 23, in which the point O on the optical axis of the concave mirror 1 ′ is located inside the focal point F (focal length f).
  • F focal point
  • the concave mirror 1 ' is regarded as a convex lens having the same positive refractive power, and the object point and the convex lens (for the sake of explanation, shown in FIG. The relationship was shown.
  • the distance from the concave mirror 1 ′ to the virtual image is increased, that is, the windshield that is the final reflection surface
  • a device for displaying an image and a projection optical system for projecting the image displayed on the display device are provided, and the projection optical system is provided.
  • the display device has a first mirror and a second mirror in the optical path of a viewer from the display device, the incident angle of the image in the major axis direction of the first mirror and the incident angle of the image in the minor axis direction of the first mirror, and the display device
  • the miniaturization is realized by satisfying a predetermined condition for the relationship between the distance between the image display surface and the first mirror and the horizontal width of the virtual image visually recognized by the viewer.
  • a windshield in which an intermediate film having a wedge-shaped cross section is formed between two pieces of glass is relatively expensive from the manufacturing process, and therefore lacks economy and generality.
  • the present invention relates to an information display apparatus for observing an image as a virtual image through a windshield, and particularly, practically reduces visibility due to double image formation of a virtual image that occurs when a normal windshield is used as a reflection surface. It is an object of the present invention to provide an information display device and an image display method for the information display device, which can be formed at a reduced level without any problem.
  • an information display device or an information display method for displaying virtual image image information on a windshield of a vehicle wherein the information display device is A display that displays video information, and a virtual image optical system that displays a virtual image in front of the vehicle by reflecting light emitted from the display on the windshield, wherein the virtual image optical system includes a concave mirror and an optical system.
  • the optical element is disposed between the display and the concave mirror, and a distortion of a virtual image obtained corresponding to a driver's viewpoint position by the shape of the concave mirror and the shape of the optical element.
  • the information display device of the present invention while optimizing the shape and arrangement of the optical element corresponding to the image light flux that establishes each virtual image separated between the display and the concave mirror, a general While adopting the windshield, it is possible to reduce the double image of the virtual image caused by the reflection of the image light flux on the front and back surfaces of the general windshield, and reduce the double image to a level that causes no problem in practical use.
  • FIG. 1 is a schematic configuration diagram illustrating an information display device and peripheral device configurations according to an embodiment of the present invention.
  • FIG. 1 is a top view of a vehicle equipped with an information display device. It is a figure explaining the difference of the curvature radius of a windshield. It is a schematic structure figure showing an example of a distant display virtual image optical system of an information display device. It is a schematic structure figure showing an example of a near field display virtual image optical system of an information display device.
  • FIG. 3 is a schematic diagram illustrating the principle of double image generation. It is the schematic explaining the virtual image which a driver visually recognizes by a double image.
  • FIG. 1 is a top view of a vehicle equipped with an information display device. It is a figure explaining the difference of the curvature radius of a windshield. It is a schematic structure figure showing an example of a distant display virtual image optical system of an information display device. It is a schematic structure figure showing an example of a near field display virtual image optical system of an information display device.
  • FIG. 2 is a first schematic configuration diagram illustrating an information display device, a windshield, and a viewpoint position of a driver and illustrating generation of a double image.
  • FIG. 11 is a characteristic diagram illustrating a result of simulating a virtual image distance and a shift amount of a double image. It is a 2nd schematic block diagram which shows an information display apparatus, a windshield, and the viewpoint position of a driver, and shows generation
  • FIG. 9 is a characteristic diagram illustrating a simulation result of a relationship between a virtual image distance at which a human having a visual acuity of 0.3 can identify a double image and a radius of curvature of a windshield when an incident angle of video light is 50 degrees.
  • FIG. 11 is a characteristic diagram illustrating a result of simulating a virtual image distance and a shift amount of a double image. It is a 2nd schematic block diagram which shows an information display apparatus, a windshield, and the viewpoint position of a driver, and
  • FIG. 9 is a characteristic diagram illustrating a simulation result of a relationship between a virtual image distance at which a human having a visual acuity of 0.3 can identify a double image and a radius of curvature of a windshield when an incident angle of video light is 60 degrees.
  • FIG. 10 is a characteristic diagram illustrating a result of a simulation of a relationship between a virtual image distance at which a human having a visual acuity of 0.3 can identify a double image and a radius of curvature of a windshield when an incident angle of video light is 70 degrees.
  • FIG. 10 is a characteristic diagram illustrating a result of a simulation of a relationship between a virtual image distance at which a human having a visual acuity of 0.3 can identify a double image and a radius of curvature of a windshield when an incident angle of video light is 70 degrees.
  • FIG. 3 is a detailed view showing a structure of a light guide constituting a backlight of the liquid crystal panel. It is a schematic diagram for explaining a change of reflectance of glass by incidence angles by S polarization and P polarization.
  • FIG. 11 is an explanatory diagram for describing a conventional technique for reducing a double image generated as a virtual image.
  • FIG. 3 is a schematic diagram for explaining the principle of a virtual image optical system according to the related art.
  • FIG. 1 is a schematic configuration diagram showing a peripheral device configuration of an information display device according to an embodiment of the present invention.
  • an information display device 100 that projects an image on a windshield of an automobile is shown. explain.
  • the information display device 100 forms the virtual image V1 in front of the host vehicle in the driver's line of sight 8
  • various information reflected on the projection target member 6 is used as the virtual image VI.
  • It is a device (so-called HUD (Headup @ Display)) for displaying as (Virtual @ Image).
  • the projected member 6 may be a member on which information is projected.
  • a combiner may be used.
  • any device may be used as long as a virtual image is formed in front of the own vehicle in the driver's line of sight 8 so that the driver can visually recognize the virtual image.
  • it also includes information and foreground information captured by a camera (not shown) such as a surveillance camera or an around viewer.
  • the information display device 100 includes the video display device 4 and a control device 40 that controls the backlight 5.
  • the optical components including the video display device 4 and the backlight 5 are virtual image optical systems described below, and include the concave mirror 1 that reflects light. The light reflected by the optical component is reflected by the projection target member 6 and travels to the driver's line of sight 8 (Eye Box: described later in detail).
  • the image display device 4 includes, for example, an LCD (Liquid Crystal Display) having a backlight and a self-luminous VFD (Vacuum Flourescent Display).
  • LCD Liquid Crystal Display
  • VFD Vauum Flourescent Display
  • an image is displayed on a screen by a projection device, and a virtual image is formed by the concave mirror 1 and reflected by a windshield 6 which is a projection target member to be directed to a viewpoint 8 of a driver. You may let it go.
  • Such a screen may be constituted by, for example, a microlens array in which microlenses are arranged two-dimensionally.
  • the shape of the concave mirror 1 is set above the general windshield 6 shown in FIG. 1 (below the windshield 6 whose distance from the driver's viewpoint is relatively short).
  • the radius of curvature is relatively small so that the enlargement ratio is large, and on the other hand, the lower part (the area where light rays are reflected above the windshield 6 that is relatively long from the driver's viewpoint).
  • the radius of curvature is relatively large so that the enlargement ratio is small.
  • even better correction can be realized by inclining the image display device 4 with respect to the optical axis of the concave mirror to correct the above-described difference in virtual image magnification and reducing the distortion itself.
  • the windshield 6 of the passenger car has a curvature radius Rv in the vertical direction of the main body and a curvature radius Rh in the horizontal direction, and generally has a relation of Rh> Rv. Therefore, when the windshield 6 is taken as a reflection surface, it becomes a toroidal surface of a concave mirror.
  • the shape of the concave mirror 1 is such that the virtual image magnification due to the shape of the windshield 6 is corrected, that is, the difference in the radius of curvature between the vertical direction and the horizontal direction of the windshield 6 is reduced.
  • the average radius of curvature may be different in the horizontal direction and the vertical direction so as to be corrected.
  • the shape of the concave mirror 1 is a function of the distance r from the optical axis in a spherical or aspherical shape symmetrical to the optical axis (a shape expressed by the following equation (2)). Since the horizontal cross-section and the vertical cross-section cannot be individually controlled, it is preferable to correct as a function of the coordinates (x, y) of the surface from the optical axis of the mirror surface as a free-form surface represented by the following equation (1). .
  • a lens element 2 is disposed as a transmission type optical component between the image display device 4 and the concave mirror 1, thereby controlling the emission direction of the light beam to the concave mirror 1.
  • a lens element 2 is disposed as a transmission type optical component between the image display device 4 and the concave mirror 1, thereby controlling the emission direction of the light beam to the concave mirror 1.
  • the above-described optical element 2 may be a plurality of lenses.
  • the above-described optical element 2 may be a plurality of lenses.
  • the distortion can be reduced.
  • an optical element optimally designed to improve the aberration correction ability is provided between the concave mirror 1 and the image display device 4, the technical idea or scope of the present invention may not be exceeded. Needless to say, it doesn't.
  • the optical distance between the concave mirror 1 and the image display device 4 is changed so that the display position of the virtual image is far away. , To the proximity position.
  • the image display device 4 may be arranged at an angle to the optical axis normal of the concave mirror 1 to correct the difference in the vertical magnification of the virtual image.
  • the image light beam emitted from the image display device 4 toward the concave mirror 1 is reflected on the surface of the optical element 2 disposed in the middle and returns to the image display device 4. It is known that the light is reflected again and superimposed on the original image light, thereby deteriorating the image quality.
  • the antireflection film is formed on the surface of the optical element 2 to suppress the reflection, but also one or both of the image light incident surface and the emission surface of the optical element 2.
  • the lens surface shape is restricted so that the above-mentioned reflected light does not converge on a part of the image display device 4 (for example, a shape having a concave surface facing the image display device 4). It is preferable to design.
  • the second polarizing plate corresponds to the liquid crystal panel. If they are arranged separately, deterioration in image quality can be reduced.
  • the backlight 5 of the liquid crystal panel is controlled so that the incident direction of light incident on the liquid crystal panel 4 is efficiently incident on the entrance pupil of the concave mirror 1. At this time, if the divergence angle of the light beam incident on the liquid crystal panel is reduced, the image light can be efficiently directed to the driver's eye point.
  • the contrast performance with respect to the divergence angle of the image is more remarkable in the horizontal direction, and excellent characteristics can be obtained if it is within ⁇ 20 degrees.
  • an optical means for reducing the divergence angle of light is provided as an LED (Light Emitting Diode) having a small light output change with respect to a change in ambient temperature. Further, it is preferable to perform polarization conversion using PBS (Polarizing Beam Splitter).
  • Polarizing plates are disposed on the backlight 5 side (light incident surface) and the optical element 2 side (light emitting surface) of the liquid crystal panel, thereby increasing the contrast ratio of image light (particularly, virtual images).
  • s-polarized light is preferably used as image light (see FIG. 21).
  • a high contrast ratio can be obtained by using an iodine-based polarizing plate having a high degree of polarization as the polarizing plate provided on the backlight 5 side (light incident surface).
  • a dye-based polarizing plate on the optical element 2 side (light emitting surface) high reliability can be obtained even when external light is incident or when the environmental temperature is high.
  • a ⁇ / 4 plate is disposed on the optical element side of the polarizing plate disposed on the optical element 2 side of the liquid crystal panel, thereby converting image light aligned in a specific polarization direction into circularly polarized light.
  • the control device 40 outputs various types of information from the navigation system 61 such as the speed limit and the number of lanes of the road corresponding to the current position where the own vehicle is traveling, and the planned travel route of the own vehicle set in the navigation system 61.
  • Information is acquired as foreground information (that is, information displayed in front of the host vehicle by the virtual image).
  • the driving support ECU 62 is a control device that realizes driving support control by controlling a driving system and a control system according to an obstacle detected as a result of monitoring by the peripheral monitoring device 63.
  • the driving support control for example, Includes well-known technologies such as cruise control, adaptive cruise control, pre-crash safety, and lane keeping assist.
  • the periphery monitoring device 63 is a device that monitors the situation around the own vehicle. For example, a camera that detects an object existing around the own vehicle based on an image of the surroundings of the own vehicle, a search wave, And an exploration device that detects an object existing around the own vehicle based on the result of transmitting and receiving the vehicle.
  • the control device 40 acquires information (for example, the distance to the preceding vehicle, the direction of the preceding vehicle, the position where an obstacle or a sign is present, etc.) from the driving support ECU 62 as foreground information. Further, an ignition (IG) signal and vehicle state information are input to the control device 40.
  • the own vehicle state information is information acquired as vehicle information, for example, when a predetermined abnormal state such as the remaining amount of fuel of the internal combustion engine or the temperature of cooling water is detected. Contains warning information to represent. It also includes the operation result of the direction indicator, the traveling speed of the host vehicle, and shift position information.
  • the control device 40 described above is activated when an ignition signal is input. The above is the description of the information display device overall system according to the present embodiment.
  • FIG. 2 is a top view of an automobile equipped with the information display device 100 according to the present embodiment as described above.
  • a windshield as the projection target member 6 is present at the front of the driver's seat of the automobile main body 101. .
  • the windshield has a different inclination angle with respect to the vehicle body depending on the type of automobile.
  • the inventors have investigated the radius of curvature in order to realize an optimal virtual image optical system. As a result, as shown in FIG. 3, the windshield differs between a horizontal curvature radius Rh parallel to the ground plane of the vehicle and a vertical curvature radius Rv perpendicular to the horizontal axis. In general, the following relationship was found between Rvs. Rh> Rv
  • Rh relative to Rv the difference between the radii of curvature, that is, Rh relative to Rv, was often in the range of 1.5 to 2.5 times.
  • the inventors also investigated a commercially available product regarding the inclination angle of the windshield.
  • the difference between the horizontal curvature radius Rh parallel to the ground contact surface of the windshield and the vertical curvature radius Rv perpendicular to the horizontal axis and the inclination angle of the windshield are considered.
  • a virtual image optical system was designed.
  • FIG. 4 is a diagram showing a state in which the image forming position of the virtual image is set far from the driver, and the angle ⁇ 1 at which the image light is reflected with respect to the windshield because the driver's line of sight for viewing the virtual image goes far away. Become smaller.
  • the image light is reflected on the windshield.
  • the angle ⁇ 2 becomes larger than the aforementioned ⁇ 1.
  • the inventors have developed a technique for reducing the double image formation of the virtual image because the degree of the double image generated varies depending on the position of the driver's line of sight (the image formation position of the virtual image).
  • the virtual image reflected by the upper part of the windshield and seen by the driver has a thickness of the windshield because the inclination of the windshield and the light rays that generate the virtual image are obliquely incident on the windshield.
  • Let t be a reflection position P0 of regular light reflected on a reflection surface close to the driver (hereinafter referred to as reflection surface 1), and a back surface reflection reflected on a reflection surface farther from the driver (hereinafter referred to as reflection surface 2).
  • the light reflection position P1 is shifted upward by the distance L in the vertical direction, and two virtual images are formed.
  • the image viewed by the driver looks like a virtual image with normal light and a virtual image generated by the reflected light on the back surface, two vertically overlapping.
  • the cause will be described in detail below.
  • the image light is natural light in which a P wave and an S wave are mixed
  • the normal virtual image due to the normal light and the second virtual image due to the back surface reflected light have the same reflectance of 4% of the incident light that enters the windshield from the air and the reflectance of 4% at the interface between the windshield and the air.
  • the brightness of the virtual image due to the back-surface reflected light is substantially equal. For this reason, the reduction of the brightness of the virtual image due to the reflected light on the back surface is indispensable for obtaining good resolution performance of the image by the virtual image.
  • the virtual image reflected by the lower portion of the windshield and visually recognized by the driver is such that the driver's line of sight is directed downward, and the light beam that generates the tilt of the windshield and the virtual image is generated by the front. Since the light is obliquely incident on the windshield as compared with the upper part of the glass, the amount by which the reflected light from the back surface and the regular reflected light are vertically shifted becomes large.
  • the back reflection light is shifted in a direction away from the point where the optical axis of the concave mirror intersects the windshield with respect to the regular reflection light, and two virtual images are formed.
  • the relationship between the angle of incidence of the image light beam on the windshield and the reflectance is such that the reflectance is about 4% for both S-polarized light and P-polarized light at normal incidence.
  • the incident angle exceeds 25 degrees, the reflectance of S-polarized light increases.
  • the reflectance of the windshield differs depending on which side of the polarization of the image output light is used. There is the possibility of changing with the angle.
  • the angle at which the image light beam enters the windshield increases, and double images occur at the top, bottom, left and right of the screen, and the virtual image focuses. Inhibits feeling.
  • the average radius of curvature of the vertical cross-sectional shape of the optical element 2 and the average radius of curvature of the horizontal cross-sectional shape are set to different values, and the above-described difference between the vertical radius of curvature Rv and the horizontal radius of curvature Rh of the windshield is determined.
  • the distortion that is caused by the generated optical path difference and that reduces the distortion and the imaging performance of the virtual image is corrected.
  • the optical path difference caused by the difference between the vertical curvature radius Rv and the horizontal curvature radius Rh of the windshield 6 causes Correction of the generated aberration is most important in securing the imaging performance of the virtual image.
  • the present inventors have developed an aspherical shape that defines the shape of a lens surface or a mirror surface as a function of the distance r from the optical axis, which has been used in conventional optical design (see the following equation (2)).
  • a free-form surface shape (see equation 1 below) that can define the shape of a surface as a function of absolute coordinates (x, y) from the optical axis.
  • the information display device reflects a virtual image on the windshield to form an image in the driver's eye box. For this reason, the image light beam is separated into regular reflected light reflected on the reflective surface 1 on the vehicle interior side of the windshield and back reflected light reflected on the reflective surface 2 in contact with the outside air. Will be recognized as The direction in which the double image is generated differs depending on the vertical direction and the horizontal direction of the windshield.
  • the double image generated by the reflected light on the back surface is the same as that shown in FIG. As shown in FIG. 5, it occurs at the top of the image due to the regular reflection light.
  • the double image generated by the reflected light on the back surface is generated at the upper part of the image by the regular reflected light.
  • FIG. 8 shows the above-described relationship, that is, assuming that the angle of the position where the virtual image is displayed with respect to the horizontal lines L1 and L0 is a dip, the virtual image 1 due to the surface reflected light of the windshield 6 having a general structure. Is formed at the position of the ray angle ⁇ s from the driver's eye P10 (viewpoint), and the virtual image 2 due to the back surface reflected light is formed at the position of the ray angle ⁇ r.
  • the deviation angle between the front surface reflection point and the back surface reflection point which is the difference between these ray angles, is as shown by the curve indicated by ⁇ in the figure, and when the virtual image distance from the line of sight P10 is small (close), the surface reflection light
  • the deviation (double image formation) of the double image due to the virtual image 1 and the virtual image 2 due to the back surface reflected light is large, but the deviation (double image formation) of the double image becomes smaller as the virtual image distance becomes longer (farther).
  • the virtual image distance exceeds 16 m
  • the deviation angle between the front reflection point and the back reflection point is 0.017 deg
  • the deviation angle between the front reflection point and the back reflection point is 0.012 deg.
  • the human eye with a visual acuity of 1.0 can discriminate the double image by the surface reflection light and the rear surface reflection light. (Usually the human (driver) discrimination limit range).
  • the image in which a virtual image is reflected by a general windshield to form an image in the driver's eye box is limited to the above-described double image discrimination (normal human (driver)
  • the use of a general windshield makes it difficult to double image a virtual image caused by the reflection of an image light beam on the front and back surfaces of the windshield. It has been found that the information display device can be formed with a reduced level to an unacceptable level, thereby achieving an information display device which is small and forms virtual images at a plurality of positions corresponding to the driver's viewpoint position.
  • the image light of the HUD which is emitted / reflected from the image display device 4 of the information display device 100 to the general windshield 6 via the concave mirror 1 and enters the driver's eye (line of sight) P10.
  • the virtual image is set so as to form a virtual image beyond the driver's eye (viewpoint) P10 beyond the limit range of normal human discrimination, for example, more than 16 m or 20 m from the viewpoint P10, or in a view distance area around the same.
  • the normal human determination limit range is, as a more specific example, 16 m or more from the driver's eyes (viewpoint) P10, more preferably 30 m to 200 m. It became clear that it was preferable to set the range.
  • the position of the driver's eye (viewpoint) P10 important for setting the ray angle ⁇ is determined by the camera input to the driver monitoring system 64 constituting the entire information display device system also shown in FIG. It can be easily detected by using the image of the driver from 77.
  • the adjustment based on the change in the position of the driver's eye (viewpoint) P10 causes the video display device 4 to adjust the image display device 4 based on the detected position of the driver's eye (viewpoint) P10. It will be apparent to those skilled in the art that the present invention can be easily and automatically realized by changing the tilt angle with respect to one optical axis or the position of the HUD information image on the video display device 4.
  • the display position of the HUD information image can be changed in accordance with the driver's eyesight by inputting the driver's eyesight in advance or as needed.
  • the thickness of the windshield is generally about 5 mm ⁇ 1 mm at the center, and as the thickness increases, the shift amount of the double image also increases.
  • the inventors also paid attention to the variation in the thickness of the windshield, particularly when the thickness of the upper end and the lower end varied, and the thickness Td of the lower end was smaller than the thickness Tu of the upper end.
  • the thickness of the windshield must be controlled not only the average thickness but also the variation in the thickness of the upper, lower, left and right edges greatly affects the absolute value of the shift amount of the double image.
  • the curvature radius of the glass surface on the driver side of the windshield and the surface in contact with the outside world are described as being the same (parallel plate) in the portion where the light flux forming the virtual image is reflected. If the thickness differs between the upper part and the lower part, a double image will result. In the range of 30 m to 50 m from the driver's eye (viewpoint) P10, the angle difference caused by this difference in thickness is preferably 0.003 degrees or less, and in the range of 50 m to 200 m, the angle difference is preferably 0.005 or less. It was revealed.
  • a general windshield having a uniform thickness has been described as a preferable example of the above-described projection target member 6.
  • the windshield has a wedge-shaped cross section (the thickness changes in the vertical direction), and the effect is limited. It is also possible to easily apply the present invention to a windshield in which an intermediate film having a wedge-shaped cross section is formed between two pieces of glass. In this case, particularly for a windshield having a wedge-shaped cross section, the important ray angle ⁇ varies depending on the position (height direction) of the driver's eyes (viewpoint) P10.
  • the position of the (viewpoint) P10 is confirmed by using the image of the driver from the camera of the driver monitoring system 64 by the control device 40 or the like, and the distance at which the HUD image light forms a virtual image. It may be preferable to adjust the area. More specifically, it is preferable to adjust the display position of the HUD information on the video display device 4 based on the position of (viewpoint) P10.
  • the recognition limit of the double image when the driver's visual acuity is 1.0 and the car is stationary is described.
  • the inventors have found that the ability to recognize the HUD image in the driving state is reduced in a subsequent study. I understood. That is, (1) it is not possible to watch an image while driving a moving vehicle. (2) Similarly, the dynamic visual acuity of the driver who gets on the moving object is lower than in the stationary state. For this reason, it was found that the driver's visual acuity was substantially up to about 0.3 to 0.5.
  • the thickness of the windshield is fixed at 4.7 mm (general thickness), and a virtual image distance, a radius of curvature of the windshield, and a virtual image are formed.
  • the visual acuity at the time of driving a car is 0.3 with the incident angle of the image light to the windshield as a parameter
  • the area where the amount of displacement of the double image at this time is less than 0.05 deg in recognition angle difference is shown in FIG. From the simulation.
  • FIG. 11 shows that, when the incident angle of the image light to the windshield is 50 deg, the radius of curvature of the windshield is infinite (flat or flat), and the normal light is 20,000 mm, 10000 mm, 7500 mm, and 5000 mm, and the virtual image distance is a parameter.
  • the figure shows the result of a simulation in which the amount of deviation between (reflected light on the front glass surface) and the reflected light on the back surface is set as a relative angle. If the virtual image distance is fixed, the relative angle becomes smaller as the radius of curvature of the windshield becomes larger. It goes without saying that if the thickness of the windshield increases, the relative angle increases even under the same conditions.
  • the relative angle that can be identified becomes smaller. For example, if the virtual image distance is 10 m, it has been found that the windshield needs to have a radius of curvature of 10,000 mm or more in order to satisfy a relative angle of 0.05 deg that can be identified by a driver having a dynamic visual acuity of 0.3.
  • FIG. 12 shows that, when the incident angle of the image light to the windshield is 60 deg, the radius of curvature of the windshield is infinite (flat), 20,000 mm, 10,000 mm, 7500 mm, and 5000 mm, and the virtual image distance is used as a parameter as a normal value.
  • the simulation result is shown as a relative angle using a shift amount of light (reflected light on the front glass surface) and reflected light on the back surface. If the virtual image distance is fixed as in the result shown in FIG. 11, the relative angle becomes smaller as the radius of curvature of the windshield becomes larger. Further, when the thickness of the windshield is increased similarly to the result obtained in FIG. 11, it goes without saying that the relative angle increases even under the same conditions.
  • the relative angle that can be identified becomes even smaller. It has been found that in order to satisfy the relative angle of 0.05 deg that can be recognized by a driver having a dynamic visual acuity of 0.3, if the radius of curvature of the windshield is 10,000 mm, the virtual image distance must be 12.1 m or more.
  • FIG. 13 shows that, when the incident angle of the image light to the windshield is 70 deg, the radius of curvature of the windshield is infinite (flat), 20,000 mm, 10000 mm, 7500 mm, and 5000 mm, and the virtual image distance is used as a parameter.
  • the simulation result is shown as a relative angle using a shift amount of light (reflected light on the front glass surface) and reflected light on the back surface. If the virtual image distance is fixed as in the results shown in FIGS. 11 and 12, the relative angle becomes smaller as the radius of curvature of the windshield becomes larger. Further, when the thickness of the windshield increases as in the results obtained in FIGS. 11 and 12, it goes without saying that the relative angle increases even under the same conditions.
  • the relative angle that can be identified becomes even smaller.
  • a virtual image distance of 14.5 m or more was required when the radius of curvature of the windshield was 10,000 mm.
  • FIG. 14 is a virtual image when the relative angle is set to 0.05 deg when the incident angle of the image light on the windshield is changed from 50 deg for a general passenger car to 70 deg for the sport type with a large inclination of the windshield.
  • the relationship between the distance and the curvature (1 / radius of curvature) of the windshield is summarized from the results of the above-described study. From this result, to satisfy the condition that the double image of the virtual image cannot be recognized, it is necessary to increase the virtual image distance and the radius of curvature of the windshield as the incident angle of the image light to the windshield increases. understood.
  • the radius of curvature of the windshield is 20,000 mm or more, if the incident angle is in the range of 50 deg to 70 deg, if the virtual image distance is 5 m or more, it becomes difficult to distinguish double images. Similarly, if the virtual image distance is 15 m or more, the radius of curvature of the windshield may be 10,000 mm or more.
  • the radius of curvature of the windshield is 8000 mm or less even if the virtual image distance is 25 m or more in a design in which the incident angle of the image light beam exceeds 70 deg. In this case, a double image occurs.
  • the image light flux is reflected by the front and back surfaces of the windshield.
  • an information display device that is small and capable of forming virtual images at a plurality of positions corresponding to a driver's viewpoint position by reducing double image generation of a generated virtual image to a level that causes no practical problem. Can be.
  • FIG. 15 is an enlarged view of a main part of the liquid crystal panel and the backlight 5 as the virtual image optical system image display device 4 according to the above-described embodiment.
  • An image is displayed on the liquid crystal panel display surface 11 by modulating light from a backlight with an image signal input from the flexible substrate 10 of the liquid crystal panel, and the displayed image is displayed on a virtual image optical system (in the embodiment, a free-form concave surface).
  • a virtual image is generated by a mirror and a free-form surface optical element, and the image information is transmitted to the driver.
  • a relatively inexpensive and highly reliable LED light source is used as the solid-state light source for the light source element of the backlight light source 5. Since the LED uses a surface-emitting type in order to increase the output, the light utilization efficiency is improved by using a technical device described later.
  • the luminous efficiency with respect to the input power of the LED varies depending on the luminescent color, but is about 20 to 30%, and most of the rest is converted to heat. For this reason, as a frame on which the LED is mounted, a radiating fin 13 made of a member having a high thermal conductivity (for example, a metal member such as aluminum) is provided to dissipate heat to the outside, thereby improving the luminous efficiency of the LED. The effect of improving is obtained.
  • LEDs that emit red light on the market today have a large decrease in luminous efficiency when the junction temperature increases, and at the same time change the chromaticity of the image, so raise the priority of LED temperature reduction, It is preferable to increase the cooling efficiency by increasing the area of the corresponding radiation fin.
  • the light guide 18 is used in the examples shown in FIGS. 19 and 20. It is preferable to combine them as a backlight light source that covers the light source.
  • FIG. 16 is an enlarged view of a main part of a light source unit including an LED as a light source, a light guide, and a diffusion plate.
  • the light funnels 21, 22, The openings 21a, 22a, 23a, and 24a for taking in the divergent light rays from the LEDs 23 and 24 are made flat, and a medium is inserted between the openings and optically connected to the LEDs, or the light is condensed as a convex shape.
  • the diverging light source light is made as parallel light as possible, and the incident angle of light incident on the interface of the light funnel is reduced.
  • the divergence angle can be further reduced after passing through the light funnel, it is easy to control the light source light traveling toward the liquid crystal panel after being reflected by the light guide 18 (see FIGS. 19 and 20).
  • polarization conversion is performed using a PBS (Polarizing Beam Splitter) at the joint 25 between the light funnels 21 to 24 and the light guide 18 so as to obtain a desired polarization direction.
  • PBS Polarizing Beam Splitter
  • a material having a low birefringence is used as the material of the light guide 18, so that when the polarization direction rotates and passes through the liquid crystal panel, for example, it is more preferable to prevent problems such as coloring when displaying black.
  • the luminous flux from the LED whose divergence angle is reduced is controlled by the light guide, reflected by the total reflection surface provided on the slope of the light guide 18, and between the facing surface and the liquid crystal panel. After being diffused by the disposed diffusion member 14, the light enters the liquid crystal panel as the image display device 4.
  • the diffusion member 14 is disposed between the light guide 18 and the liquid crystal panel 4.
  • the light guide 18 has a diffusion effect on its end face. The same effect can be obtained even if it is provided.
  • FIG. 17A is a diagram illustrating a light emitting state as viewed from the longitudinal direction of the liquid crystal panel
  • FIG. 17B is a diagram illustrating a light emitting state as viewed from the lateral direction of the liquid crystal panel.
  • the horizontal diffusion angle is increased with respect to the vertical direction. Is designed so that the brightness of the virtual image visually recognized by the eyes does not change extremely.
  • FIG. 18 shows the luminance distribution on the emission surface of the liquid crystal panel 4 when using a backlight in which the light emission direction and intensity are controlled by using the light guide 18 as in the present embodiment.
  • the inclination of the luminance decrease outside the effective range in the screen vertical direction (long side direction) can be reduced.
  • the emitted light (image light) from the liquid crystal panel used as the image display device in the information display device 100 of the present embodiment exhibits a predetermined transmittance in a range of ⁇ 50 ° when the viewing angle in the left, right, up and down directions is a parameter. . If the range of the viewing angle is within ⁇ 40 °, better transmittance characteristics can be obtained. As a result, as shown in FIGS. 17 and 18, the brightness of the screen greatly differs depending on the viewing direction (viewing angle) in the horizontal direction and the vertical direction of the display screen. This depends on the angle characteristics of the backlight luminance.
  • the inventors set the angle of the total reflection surface of the light guide 18 and the light funnels 21 to 24 so that the light emitted from the liquid crystal panel 4 to be taken into the virtual image optical system can be obtained as light as perpendicular to the screen as possible.
  • the viewing angle characteristics of the backlight were narrowed down to a small range, thereby obtaining high luminance.
  • light within a range of ⁇ 30 ° in the left and right viewing angles is used, and in consideration of the contrast performance, by narrowing down to ⁇ 20 ° or less, a good image quality is obtained at the same time.
  • the contrast performance that affects the image quality of the video display device is determined by how much the brightness in black display, which is the basis for determining the image quality, can be reduced. Therefore, it is preferable to use an iodine-based polarizing plate having a high degree of polarization between the liquid crystal panel 4 and the backlight.
  • a PBS is arranged between the light funnel and the light guide to align the polarized light to a specific polarization, thereby reducing damage to the polarizing plate on the liquid crystal panel incident side. I do.
  • the polarization direction of the polarizing plate disposed on the liquid crystal panel incident side should be the direction in which the polarized light having a specific direction passes after passing through the PBS.
  • the image display device 4 As described above, as the image display device 4 according to the embodiment of the present invention, it is possible to provide a ⁇ / 4 plate on the emission surface of the liquid crystal display panel to make the emitted light circularly polarized. As a result, the driver can monitor a favorable virtual image even when wearing polarized sunglasses.
  • the reflection film of the reflection mirror used in the virtual image optical system is formed of a metal multilayer film, the angle dependence of the reflectance is small, and the reflectance changes depending on the polarization direction (P wave or S wave). Therefore, the chromaticity and brightness of the screen can be kept uniform.
  • the liquid crystal display panel can be used. Further, since the polarizing plate can be reduced from its temperature rise and damage, the effect of not impairing the reliability of the information display device can be obtained.
  • the virtual image optical system performs an optimal design including a difference between a curvature radius in a vehicle horizontal direction and a curvature radius in a vertical direction of a windshield, which has been a projection target member in the related art, and a windshield and an image display device or an intermediate device.
  • a concave mirror 1 having a concave surface facing the windshield 6 is arranged between the image display unit and the image display unit, whereby the image on the image display device 4 is enlarged and reflected on the windshield 6.
  • an optical element is arranged between the concave mirror 1 and the image display device 4, and an enlarged image (virtual image) of the image formed corresponding to the driver's viewpoint position is formed.
  • the image light flux passing through the optical element disposed between the image display devices corrects distortion and aberration generated in the concave mirror 1. Therefore, it is possible to obtain a virtual image in which distortion and aberration are greatly reduced as compared with a conventional virtual image optical system including only a concave mirror.
  • the present invention while optimizing the shape and position of the optical element corresponding to the image light flux that establishes each virtual image separated between the display and the concave mirror, general Despite the use of a typical windshield, it is possible to reduce the double image of a virtual image caused by the reflection of the image light flux on the front and back surfaces of the windshield to a level that does not cause a practical problem. By doing so, it is possible to provide an information display device which is small and forms the plurality of virtual images at a plurality of positions corresponding to the driver's viewpoint position.
  • planar light source device suitable for use in an electronic device having an image display device according to various embodiments of the present invention.
  • the present invention is not limited to the above-described embodiment, but includes various modifications.
  • the entire system is described in detail in order to easily explain the present invention, and the present invention is not necessarily limited to those having all the described configurations.
  • a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added to the configuration of another embodiment.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Instrument Panels (AREA)
  • Fittings On The Vehicle Exterior For Carrying Loads, And Devices For Holding Or Mounting Articles (AREA)

Abstract

L'invention concerne un dispositif d'affichage d'informations pour afficher des informations d'image d'une image virtuelle sur un pare-brise d'un véhicule, et un procédé d'affichage d'informations associé. Le dispositif d'affichage d'informations est pourvu d'un élément d'affichage qui affiche les informations d'image, et d'un système optique d'image virtuelle qui fait s'afficher l'image virtuelle devant le véhicule par réflexion de la lumière émise depuis l'élément d'affichage par le pare-brise. Le système optique d'image virtuelle comprend un miroir concave et un élément optique, et l'élément optique est disposé entre l'élément d'affichage et le miroir concave, et conçu pour corriger la distorsion de l'image virtuelle obtenue en fonction de la position de point de vue d'un conducteur conformément à la forme du miroir concave et à la forme de l'élément optique, et comprend un moyen ou une étape pour former l'image virtuelle générée par un flux de lumière d'image qui est réfléchi par la surface avant et la surface arrière du pare-brise dans une région de distance de champ de vision dépassant la plage de limite de discrimination du conducteur ou autour de la plage de limite de discrimination par réglage de la position de l'image virtuelle à former selon un angle d'incidence de lumière d'image sur le pare-brise et le rayon de courbure du pare-brise devant la position de la ligne de visée du conducteur.
PCT/JP2019/028353 2018-08-09 2019-07-18 Dispositif d'affichage d'informations et procédé d'affichage d'informations WO2020031654A1 (fr)

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JP7225272B2 (ja) * 2021-01-12 2023-02-20 矢崎総業株式会社 車両用表示装置

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WO2018008236A1 (fr) * 2016-07-07 2018-01-11 マクセル株式会社 Dispositif d'affichage tête haute
JP2019034708A (ja) * 2017-08-11 2019-03-07 創智車電股▲ふん▼有限公司Ｃｏｎｓｅｒｖｅ＆Ａｓｓｏｃｉａｔｅｓ，Ｉｎｃ． 普通のフロントガラスを使用したディスプレイ装置、および、その自動車のヘッドアップディスプレイシステム

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CN114690277B (zh) * 2020-12-28 2024-04-02 上海中航光电子有限公司 镀膜衬底及显示系统

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