Head-up display device

Abstract

To provide a head-up display device with which it is possible to detect an object which is located so as to obstruct a display.SOLUTION: Provided is a head-up display device 1 that includes a light source 14 for emitting light, a display unit 17 for generating display light 2 by the light, and a refraction unit 15 for refracting the light or the display light 2, with the display light 2 reflected by a reflection unit 3 and displayed as virtual images V1, V2 to a viewer 4, the head-up display device 1 comprising a hollow cylindrical unit 51 which is located on the display surface 17a side of the display unit 17, and a light detection unit 6 which is located in the cylindrical unit 51, for detecting light 2a that is refracted in a direction opposite the direction in which the display light 2 is refracted.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a head-up display device mounted on a vehicle or the like.

Background Art

[0002] Conventional head-up display devices, for example, as disclosed in Patent Document 1, dispose a display in a recess provided by recessing the upper surface of an instrument panel near the position of the front windshield (windshield) of a vehicle downward, and reflect display light from this display on a colored portion covering the periphery of the front windshield to perform display as a virtual image for a driver.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when an object falls into the recess, there is a problem that the display light is blocked and a virtual image cannot be displayed. Further, there is also a problem that it is difficult for a driver to notice.

[0005] The present invention has been made in view of the above actual situation, and an object thereof is to provide a head-up display device capable of detecting an object disposed so as to block a display.

Means for Solving the Problems

[0006] The head-up display device 1 of the present invention includes a light source 14 that emits light, a display unit 17 that generates display light 2 by the light, and a refraction unit 15 that refracts the light or the display light 2. In the head-up display device 1 that reflects the display light 2 by a reflection unit 3 and performs display as virtual images V1 and V2 for a viewer 4, a hollow cylindrical portion 51 disposed on the display surface 17a side of the display unit 17, and light 2a that is disposed in the cylindrical portion 51 and refracted in a direction opposite to the refraction direction of the display light 2 Illuminance and a light detection unit 6 that detects the light 2a The light detection unit 6 outputs the illuminance to the control unit. When the illuminance is equal to or lower than the threshold value, the control unit determines that it is abnormal and performs a process of issuing a warning to the viewer 4 characterized by this.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0008] Embodiments of the head-up display device of the present disclosure will be described with reference to the accompanying drawings 1 to 7. The head-up display device of the present disclosure can be applied to head-up display devices mounted on vehicles such as automobiles and motorcycles, ships, agricultural machinery, and construction machinery. In the present embodiment, an example will be described in which the head-up display device is disposed within an instrument panel of an automobile as the mounting destination.

[0009] In the following description, "front", "rear", "upper", "lower", "right", and "left" follow the definitions "Fr.", "Re.", "To.", "Bo.", "R", and "L" in FIGS. 1 to 3.

[0010] (First Embodiment) The head-up display device 1 is a so-called head-up display (HUD), and projects display light 2 representing an image of the head-up display device 1 disposed within the instrument panel 5 of the mounting destination onto the front glass (reflective portion) 3 of the vehicle, which is a projection member, and reflects it in the direction of the driver (viewer) 4 seated in the driver's seat of the automobile. In particular, the head-up display device 1 projects and reflects the display light 2 onto the light-shielding portion 3a formed around the front glass 3, displays it as a virtual image V1, and allows the driver 4 to visually recognize it.

[0011] The light-shielding portion 3a is an opaque portion made of a light-shielding color such as black, which is made of black ceramics or the like formed at the periphery of the front glass 3. The light-shielding portion 3a is formed for the purpose of preventing deterioration of the adhesive that fixes the front glass 3 to the vehicle due to sunlight, concealing the adhesive, and improving the design.

[0012] As shown in FIG. 2, the head-up display device 1 includes at least an upper case (case body) 11, a lower case (case body) 12, a circuit board 13, a light source 14, a prism 15, an optical member 16, and a display (display portion) 17.

[0013] The upper case 11 is made of a black light-shielding synthetic resin material such as ABS (acrylonitrile butadiene styrene), and is formed in a substantially box shape with an opening at the bottom. The upper case 11 has a light-transmitting portion 11a formed at a location facing the display 17. The light-transmitting portion 11a is made of a synthetic resin material with permeability such as PMMA (acrylic).

[0014] The lower case 12 is made of a black light-shielding synthetic resin material such as ABS, and is formed in a substantially box shape with an opening at the top. The lower case 12 fits with the upper case 11 to form a box-shaped housing, and houses the circuit board 13, the light source 14, the prism (refracting portion) 15, the optical member 16, and the display 17 inside.

[0015] The circuit board 13 is made of a rigid printed circuit board such as a flat glass epoxy-based substrate. The circuit board 13 mounts various circuit components such as the light source 14, a control chip, resistors, and capacitors, and connects the various circuit components by wiring patterns to form a circuit. The circuit board 13 is electrically connected to a control unit of a vehicle (for example, an ECU (Engine Control Unit)) by a wiring member such as a harness.

[0016] The light source 14 is composed of light-emitting diodes (LEDs: Light Emitting Diodes), and a plurality of them are mounted on the upper surface of the circuit board 13. The light source 14 emits light by a light-emitting circuit (not shown) based on a control signal supplied from the control chip. The light source 14 emits light toward the prism 15.

[0017] The prism 15 is disposed on the light source 14 side of the optical member 16 and comprises a base material 15a and a refractive portion 15b. The base material 15a is made of a synthetic resin sheet such as a translucent flat plate-shaped PC (polycarbonate). The refractive portion 15b is formed by potting or the like a translucent transparent resin into an uneven shape on the light source 14 side of the base material 15a. As shown in FIG. 2, the refractive portion 15b is formed in a cross section having a continuous triangular shape (sawtooth shape) with the light source 14 side becoming narrower, and the triangle has optical anisotropy due to its asymmetric shape. The refractive portion 15b refracts the light from the light source 14 and irradiates this light toward the display 17 side at a predetermined angle. The light transmitted through the display 17 is irradiated toward the front glass 3.

[0018] The prism 15 is designed according to the emission direction of the display light 2 emitted from the head-up display device 1. When the display light 2 is reflected by the light-shielding portion 3a of the front glass 3 and visually recognized by the driver 4, the shape, optical characteristics, etc. of the refractive portion 15b are determined so as to obtain an optimal angle (reflection angle at which it appears bright). Here, the display light 2 is determined to be emitted at an angle inclined approximately 20 degrees with respect to the normal direction of the display surface 17a of the display 17.

[0019] The optical member 16 is disposed between the display 17 and the prism 15 and diffuses the illumination light emitted from the prism 15. A total of three sheets are provided for the optical member 16, including a prism sheet with streak-like unevenness on the surface provided on the display 17 side and a diffusion sheet with granular unevenness on the surface provided behind it. The prism sheet is an optical film such as a BEF (Brightness Enhancement Film) with unevenness on the surface. The number, order, and type of the optical member 16 may be appropriately set and arranged.

[0020] Since the prism 15 is formed in an uneven shape, dark lines (black streak-like lines visible when visually recognized) corresponding to the shape are generated. Since the optical member 16 can diffuse light, it is possible to make this dark line less noticeable.

[0021] The display 17 is a TN (Twisted Nematic) type negative (the mode where the displayed characters are translucent when lit and light-shielding when extinguished. The background is light-shielding both when lit and when extinguished) type segment LCD (Liquid Crystal Display) having segment-shaped pixels in which a liquid crystal material is sandwiched and encapsulated between two rectangular glass substrates on the top and bottom, and polarizing plates are bonded to the front and back thereof. The display 17 displays a design portion 17b formed by segments as an image. The design portion 17b has vehicle information such as a vehicle speed design, a gear positioning design, a remaining fuel design, an indicator design, and the like.

[0022] The vehicle speed design displays the speed value of the automobile by means of the design of units and a plurality of segments. The gear positioning design displays the gear position by means of the designs of P, R, N, and D. The remaining fuel design displays the remaining fuel amount by means of the designs of F, E, and a plurality of rectangular graduations. The indicator design displays operation lights and warning lights consisting of various designs such as turns.

[0023] Based on the control signal supplied from the control chip, the display 17 switches the design portion 17b. The display 17 generates display light 2 when the light emitted by the light source 14 passes through the design portion 17b. The virtual image V1 formed by the display light 2 displays vehicle speed display V11, gear positioning display V12, remaining fuel display V13, and indicator display V14 corresponding to the vehicle speed design, gear positioning design, remaining fuel design, and indicator design. Here, the vehicle speed display V11 and the remaining fuel display V13 are important images with a higher degree of importance compared to the gear positioning display V12 and the indicator display V14.

[0024] The instrument panel 5 has a recessed portion (cylindrical portion) 51 that is recessed downward. The recessed portion 51 is a recess formed in a cylindrical shape with a long rectangular cross-section that is long in the left-right direction so as to correspond to the display 17, and is composed of a front wall 51a, a rear wall 51b, side walls 51c, and a bottom hole 51d. The front wall 51a is a vertical wall on the side of the windshield 3 and is formed so as to be continuous with the windshield 3. The rear wall 51b is a vertical wall on the side of the driver 4 that faces the front wall 51a. The side walls 51c are vertical walls that connect the front wall 51a and the rear wall 51b. The bottom hole 51d is a rectangular hole opened at the lower bottom.

[0025] The display 17 is disposed below the recessed portion 51 such that the display surface 17a side faces the bottom hole 51d. Formed in this way, the display light 2 passes through the recessed portion 51, is reflected by the light-shielding portion 3a of the windshield 3, and is visually recognized by the driver 4 as a virtual image V1.

[0026] However, as shown in FIG. 4, for example, in the head-up display device 1, when an object B falls into the recessed portion 51 and blocks the display light 2, resulting in a lack of display such as the vehicle speed display V11, there is a problem that the driver 4 cannot correctly display the speed of the vehicle. In addition, when the object B is small, the driver 4 has a problem that it is difficult to notice the fall of the object B into the recessed portion 51 because the lack of display of the virtual image V1 is also small. Further, the recessed portion 51 is disposed on the side of the windshield 3 that is recessed from the driver 4 of the instrument panel 5 and has a narrow opening, so it is difficult for the driver 4 to take the object B. Therefore, there is a problem that the driver 4 has to go to an automobile repair shop and needs to detect the fall of the object B into the recessed portion 51 at an early stage.

[0027] Therefore, the present disclosure addresses the above problems. As shown in FIG. 2, the head-up display device 1 has a front wall hole (hole portion) 51e and a light detector (light detection portion) 6.

[0028] The front wall hole 51e is a hole opened in a cylindrical shape in the front wall 51a of the recessed portion 51. As shown in FIG. 3, five holes of the front wall hole 51e are arranged side by side in the left-right direction. The front wall hole 51e allows the leakage light 2a to pass through.

[0029] The leakage light 2a is light that is refracted toward the front wall hole 51e in a direction opposite to the direction in which the display light 2 is refracted. Specifically, assuming that the display light 2 is refracted in a direction approximately 20 degrees with respect to the normal direction of the display surface 17a of the display 17, the leakage light 2a is light that is refracted in a direction approximately -20 degrees with respect to the normal direction of the display surface 17a of the display 17. That is, the refraction portion 15b divides the light from the light source 14 into light that is refracted toward the front glass 3 to become the display light 2 and light that is refracted toward the front wall hole 51e to become the leakage light 2a. The leakage light 2a is approximately 10% of the light from the light source 14 and is unnecessary light that is not used for the display of the head-up display device.

[0030] The light detector 6 includes a sensor substrate 61 and a photosensor 62. The sensor substrate 61 is made of a rigid printed circuit board similar to the circuit board 13 and mounts five photosensors 62. The light detector 6 is disposed and fixed on the outer side of the front wall 51a (the side opposite to the inner side of the recess 51 (the side through which the display light 2 passes)). The sensor substrate 61 is electrically connected to the control unit of the vehicle by a harness or the like.

[0031] The photosensor 62 can be, for example, a photodiode and is disposed in each of the five front wall holes 51e. The light detector 6 detects the illuminance of the leakage light 2a that has passed through the front wall hole 51e and outputs illuminance data to the control unit of the vehicle.

[0032] The light detector 6 is driven simultaneously with the lighting of the light source 14 and the driving of the display 17. As shown in FIG. 2, the light detector 6 determines that it is normal when it detects light (leakage light 2a) equal to or greater than the threshold value while the display 17 is being driven, and does not perform a specific process. As shown in FIG. 4, when an object B falls into the recess 51, the light detector 6 continuously detects for a predetermined time a state in which the light (leakage light 2a) detected while the display 17 is being driven is blocked by the object B or the like and is below the threshold value, determines that it is abnormal, and performs a process of executing a warning to the driver 4 by sound or display.

[0033] The warning is given by displaying, on a display device other than the head-up display device 1, such as the meter 7, a message like "There is a possibility that foreign matter has entered the head-up display unit. Please contact your dealer.", or by emitting a voice message of the same content through a speaker equipped on the meter 7.

[0034] Note that the head-up display device 1 does not always drive the photodetector 6, and it may drive the photodetector 6 only for a specific period for power saving. For example, it may drive the photodetector 6 only for one hour after the vehicle power is turned on (when ACC (accessory) is ON or when IGN (ignition) is ON).

[0035] By being formed in this way, when an object B falls into the recess 51 and blocks the display light 2 so that the virtual image V1 cannot be displayed, the head-up display device 1 can quickly notify the driver 4 of the abnormality by the photodetector 6.

[0036] (Second Embodiment) A second embodiment of the display device according to the present disclosure will be described with reference to FIG. 5. The same parts and equivalent parts as those in the above-described first embodiment will be denoted by the same reference numerals and will not be described again.

[0037] The display 17 was a segment type LCD having a fixed design portion 17b, but in this embodiment, the display 17 is a full-color TFT (Thin Film Transistor) type LCD that displays various designs at the same location. The display 17 displays at least the same type of design as in the first embodiment. Also, when the vehicle power is turned on, the display 17 displays an inspection display V21 on the virtual image V2. The inspection display V21 is an image that emits light in a single color of a rectangle.

[0038] By being formed in this way, when an object B falls into the recess 51 and blocks the display light 2, the driver 4 will visually recognize the inspection display V21 with a part missing, so that the driver 4 can detect the deterioration of the object B in the recess 51. Further, even when the driver 4 does not notice the abnormality of the inspection display V21, the head-up display device 1 can quickly notify the driver 4 of the abnormality by the light detector 6.

[0039] (Third Embodiment) A second embodiment of the display device according to the present disclosure will be described with reference to FIG. 6. The same parts and equivalent parts as those in the above-described second embodiment will be denoted by the same reference numerals and described.

[0040] Although there were five front wall holes 51e, in this embodiment, only two front wall holes 51e are formed at positions corresponding to the vehicle speed display V22 and the remaining fuel display V23 of the important image, and the optical sensor 62 is arranged only at this position. By being formed in this way, the head-up display device 1 can reduce the cost of the light detector 6 by reducing the number of optical sensors 62 and the like.

[0041] (Fourth Embodiment) A fourth embodiment of the display device according to the present disclosure will be described with reference to FIG. 7. The same parts and equivalent parts as those in the above-described third embodiment will be denoted by the same reference numerals and described.

[0042] The prism 15 was arranged on the light source 14 side of the optical member 16, but in this embodiment, it is arranged between the light transmissive part 11a and the display 17. The refracting part 15b refracts the light transmitted through the display 17 and irradiates this light toward the front glass 3. By being formed in this way, the prism 15 can irradiate the front glass 3 so as to be at an optimal angle when the driver 4 visually recognizes the display light 2, similar to the first embodiment.

[0043] In this embodiment, the upper case 11 has an extension portion 11b extending toward the front wall 51a. Although the front wall hole 51e was formed in the front wall 51a, in this embodiment, it becomes an extension portion hole (hole portion) 11e which is a hole opened cylindrically in the extension portion 11b. The extension portion hole 11e allows the leakage light 2a to pass through. The optical sensors 62 are disposed respectively in the extension portion holes 11e. Although the photodetector 6 was fixed to the outside of the front wall 51a, in this embodiment, it is sandwiched and fixed between the extension portion 11b and the fixing member 18 and disposed outside the extension portion 11b.

[0044] Although the sensor substrate 61 was electrically connected to the control unit of the vehicle, in this embodiment, the sensor substrate 61 is electrically connected to the control unit of the circuit board 13 of the head-up display device 1 by a harness or the like. That is, the photodetector 6 is integrally formed with the head-up display device 1.

[0045] The extension portion hole 11e has a light guide member 63 formed of a translucent synthetic resin (for example, acrylic or the like), condenses the leakage light 2a, and guides it to the optical sensor 62. By being formed in this way, the head-up display device 1 can improve the detection accuracy of the leakage light 2a.

[0046] (Modification example) Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

[0047] For example, although the example of the head-up display device 1 that projects the display light 2 onto the light-shielding portion 3a of the front glass 3 has been described, it may be a head-up display device that projects onto the transparent portion of the front glass 3 and allows the driver 4 to visually recognize a real image or a virtual image. Further, it may be a device that projects onto, for example, a transparent or opaque reflecting portion (so-called combiner) provided on the driver 4 side of the front glass 3.

[0048] The prism 15 was disposed on the light source 14 side of the optical member 16 or between the light-transmitting portion 11a and the display 17, but it may be disposed between the display 17 and the optical member 16. The prism 15 may be a so-called light guide formed by molding a light-transmissive synthetic resin.

Description of Reference Numerals

[0049] 1 Head-up display device 11 Upper case (case body) 11a Light-transmitting portion 11b Extending portion 11e Extending portion hole (hole portion) 12 Lower case (case body) 13 Circuit board 14 Light source 15 Prism 15a Base material 15b Refracting portion 16 Optical member 17 Display (display portion) 17a Display surface 17b Design portion 18 Fixing member 2 Display light 2a Leakage light 3 Front glass (reflecting portion) 3a Light-shielding portion 4 Driver (viewer) 5 Instrument panel 51 Concave portion 51a Front wall 51b Rear wall 51c Side wall 51d Bottom hole 51e Front wall hole (hole portion) 6 Photodetector (photo-detection unit) 61 Sensor substrate 62 Photo-sensor 63 Light guide member 7 Meter B Object V1 Virtual image V11 Vehicle speed display V12 Gear positioning display V13 Remaining fuel display V14 Indicator display V2 Virtual image V21 Inspection display V22 Vehicle speed display V23 Remaining fuel display

Claims

1. A light source that emits light, A display unit that generates display light by the light, A refraction unit that refracts the light or the display light, and has, In a head-up display device that reflects the display light by a reflection unit and performs display as a virtual image to a viewer, A hollow cylindrical portion disposed on the display surface side of the display unit, A light detection unit that is disposed in the cylindrical portion and detects the illuminance of light refracted in a direction opposite to the refraction direction of the display light, Comprising, The light detection unit outputs the illuminance to a control unit, The control unit determines that it is abnormal when the illuminance is below a threshold value, and performs a process of executing a warning to the viewer. A head-up display device characterized by this.

2. The reflection unit is the front glass of a vehicle, The cylindrical portion is a recess formed in the instrument panel of the vehicle, The head-up display device according to claim 1, wherein the display light is projected onto a light-shielding portion formed at the periphery of the front glass.

3. The head-up display device according to claim 1, wherein the refraction unit is disposed between the display unit and the light source.

4. The illuminance is characterized in that it is blocked by an object and becomes below the threshold value. The head-up display device according to claim 1.

5. The head-up display device according to claim 1, wherein the light detection unit is disposed on the reflection unit side of the cylindrical portion.

6. The display unit has an important image with high importance, The head-up display device according to claim 1, wherein the light detection unit is disposed at a location corresponding to the important image.

7. The head-up display device according to claim 1, wherein the display unit displays a display for inspection.

8. The head-up display device according to claim 1, wherein the light detection unit detects the illuminance only for a specific period after the vehicle power is turned on.

Images