Head-up display

Abstract

To provide a head-up display which can perform easy-to-understand guide display.SOLUTION: A head-up display H for displaying an image with a virtual image L in a front space of a user 14 comprises: a liquid crystal display instrument 20 which projects the image; and a control unit 60 which receives input of route guide information and vehicle information, draws and generates the image to perform route guide for the user 14 on the basis of these pieces of information. The control unit 60 draws and generates the image including a guide image L4 indicating the route direction to a destination, and a road surface image L3 simulating a portion of a travel path of the own vehicle and indicating the portion in a chromatic manner and having a shadow part L6 at a lower side position of the guide image L4.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a head-up display for a vehicle, and is suitable as a display device that projects a display image onto a windshield, for example. [Background technology]

[0002] BACKGROUND ART Conventionally, as a head-up display of this type, for example, as described in Patent Document 1, a head-up display that projects display light from a display onto a windshield (projection member) of a vehicle to display a virtual image is known.

[0003] Furthermore, as the display contents of these head-up displays, for example, as described in Patent Document 2, there is a type that shows the destination of the vehicle by using a guide display such as an arrow. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-344801 [Patent Document 2] Japanese Patent Application Publication No. 2018-149884 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when this guidance display is projected onto a windshield or the like, the display is set against the background of the scenery ahead of the vehicle, making it difficult to grasp the relative positional relationship, posing a problem when used as a route guidance display.

[0006] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a head-up display that can provide easy-to-understand guidance displays by focusing on the above-mentioned problems. [Means for solving the problem]

[0007] The head-up display of the present invention is In a head-up display that displays a virtual image in the space in front of the driver, a projection unit that projects the image; a control unit that receives route guidance information and vehicle information and draws and generates the image that provides route guidance to the driver based on the information; The control unit A guide image showing the route direction to the destination; a road surface image in which a part of the road on which the vehicle is traveling is shown in color and a shadow portion is provided below the guide image; death, Furthermore, the control unit can blur the outline of the shadow and move the display position of the guide image and the corresponding shadow upward using perspective, and when the guide image is displayed at the top, the shadow is drawn with stronger blurring than when the guide image is displayed at the bottom. .

[0008] The control unit also draws the guide image with a gap between the guide image and the shadow portion. [Effects of the Invention]

[0011] The head-up display of the present invention can display guidance that is easy to understand. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram of a head-up display mounted on a vehicle according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view of a main part showing the internal configuration of the head-up display. [Figure 3] Block diagram showing the configuration related to image drawing [Figure 4] FIG. 10 is a diagram showing a display example relating to route guidance. [Figure 5] FIG. 5 is a diagram showing a display example in which the guide image has been moved from FIG. 4; DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment in which the present invention is applied to a head-up display for a vehicle will be described with reference to the accompanying drawings.

[0014] 1, a head-up display projected display light L projected by a display device 12, which is a display unit provided inside an instrument panel 11 of a vehicle 10, is reflected by a windshield 13 of the vehicle 10 toward a user (driver) 14 of the vehicle 10, thereby displaying a virtual image V. In other words, the head-up display emits (projects) display light (image) L emitted from a liquid crystal display (projection unit) 20 (described later) onto the windshield 13, and allows the user 14 to view a display image (virtual image) V obtained by this emission. This allows the user 14 to observe the virtual image V superimposed on the scenery ahead of the vehicle 10.

[0015] As shown in FIG. 2, the display device 12 is mainly composed of a liquid crystal display 20, a first reflector 30, a second reflector 40, and a housing 50.

[0016] The liquid crystal display 20 is mainly composed of a light source 21 consisting of a light emitting diode mounted on a wiring board R, and a TFT-type liquid crystal display element (display element) 22 located in front of (directly above) the light source 21 so as to transmit illumination light from the light source 21 and form display light L. This means that the light source 21 is provided behind (directly below) the liquid crystal display element 22, and the liquid crystal display element 22 displays predetermined information (information to be displayed, described later) using light emitted from the light source 21.

[0017] The liquid crystal display element 22 displays information to be displayed, such as the speed of the vehicle 10, remaining energy, time, and route guidance images, using numerical values, icons, and other images, via an element drive circuit (not shown). The liquid crystal display 20 outputs display light L consisting of light in the visible wavelength range, and for example, a light source 21 that emits white light can be applied. The light emitted from this light source 21 passes through the liquid crystal display element 22, outputting display light L containing a desired image. Note that the information to be displayed is not limited to vehicle information such as the vehicle speed and remaining energy, and any display form can be adopted.

[0018] The first reflector 30 includes a cold mirror 31. The cold mirror 31 reflects light in the visible wavelength range (450 to 750 nm), which includes the emission wavelength range of the liquid crystal display 20, with a high reflectance (e.g., 80% or more), and reflects light outside the visible wavelength range with a low reflectance. In this case, the cold mirror 31 used is one that reflects light outside the visible wavelength range, particularly light in the infrared wavelength range (infrared rays or heat rays from sunlight), with a low reflectance (e.g., 15% or less). The cold mirror 31 is configured so that light that is not reflected by the reflective layer thereof passes through the cold mirror 31.

[0019] The second reflector 40 includes a concave mirror 41 that reflects the display light L from the cold mirror 31 (that is, the liquid crystal display element 22), and a mirror holder 42 that holds the concave mirror 41.

[0020] The concave mirror 41 has a second reflective layer 41a formed by vapor deposition on a resin substrate made of polycarbonate having a concave surface. The concave mirror 41 is installed in an inclined state so that the second reflective layer 41a faces the cold mirror 31 and the translucent cover and can be seen from the translucent cover.

[0021] The concave mirror 41 magnifies the display light L from the cold mirror 31 and reflects (projects) it toward the translucent cover (windshield 13 of the vehicle 10). This means that the concave mirror 41 magnifies the display light L reflected by the cold mirror 31 and projects the magnified display light L toward the windshield 13 through the translucent cover. The concave mirror 41 is adhered to a mirror holder 42 with a double-sided adhesive member. The mirror holder 42 is made of synthetic resin (e.g., ABS resin) and is fixed to the housing 50.

[0022] The housing 50 is made of, for example, a black light-blocking synthetic resin material, and is formed in a roughly box-like shape.The housing 50 holds and accommodates the LCD display 20, the first reflector 30, and the second reflector 40 in its internal space, the space portion 51, and is provided with an opening window portion 52 that opens to the upper part (windshield 13 side) of the concave mirror 41 in the second reflector 40.

[0023] The housing 50 is also provided with a light-transmitting cover 53, which is an emission portion, to cover the open window portion 52. The light-transmitting cover 53 is made of a light-transmitting synthetic resin material (e.g., acrylic resin), is formed in a curved shape (curved surface shape), and functions as a light-transmitting member through which the display light L reflected by the concave mirror 41 passes (passes through). In other words, the display light L reflected by the cold mirror 31 and the concave mirror 41 is projected onto the windshield 13 through the light-transmitting cover 53 formed on the housing 50, thereby displaying the virtual image V.

[0024] 3, the head-up display H is provided with a circuit board (not shown) that mounts a control unit 60 that receives various signals from an on-board ECU (electronic control unit) and calculates the output contents of the liquid crystal display 20. In this case, the circuit board is held in a housing 50 of the display device 12.

[0025] The control unit 60 is powered by power supplied from an on-board battery (not shown), and can be implemented as a microcomputer equipped with a data storage unit such as a ROM or RAM (not shown) used to store predetermined programs and various data and as a memory area during calculations, a CPU that performs calculations according to the predetermined programs, and an input / output interface, etc.

[0026] The control unit 60 is connected to various on-board ECUs via a network, and includes an input port 61 for inputting route guidance information from a navigation system device and vehicle information measured by various sensors. The control unit 60 is also connected to the liquid crystal display 20, and includes a drawing processing unit 62 for generating images to be displayed on the liquid crystal display 20 based on the input route guidance information and vehicle information. The control unit 60 outputs a drive signal to the liquid crystal display 20 to prompt the image generated by the drawing processing unit 62 to be displayed.

[0027] An example of the display light (image) L generated by the control unit 60 will be described with reference to FIGS.

[0028] 4 and 5 show a route guidance display light L that is displayed when a vehicle approaches an intersection L1. In this case, an example of the display light L is shown, urging the driver to proceed straight ahead as guidance. The control unit 60 uses perspective to generate a lane marking image (including a center line image) L2 indicating the width of the road ahead of the vehicle, a road surface image L3 showing a portion of the road surface ahead of the vehicle (the side closest to the vehicle), and a guide image L4 consisting of an arrowhead icon indicating the route direction, each of which is drawn in color, and causes the display light L including these to be displayed on the liquid crystal display 20. In this case, the lane marking image L2 is drawn in white, the road surface image L3 in blue, and the guide image L4 in green. The white background in the drawings is actually drawn in black, and the view ahead of the vehicle is visible to the user 14 through the virtual image V projected onto the windshield 13.

[0029] The road surface image L3 has grid lines L5 superimposed thereon using perspective, making it easy for the user 14 to recognize distance and perspective. In addition, the road surface image L3 has a shadow L6 drawn at a distance below the guide image L4, creating the impression that it is floating above the road surface and making it recognizable. This shadow L6 is oval in shape and drawn in black (or a darker blue than the road surface image L3), and the outer edge (boundary) is blurred to indicate that it is the shadow of the guide image L4, and the distance between it and the guide image L4 makes it easy to recognize the guide position relative to the road surface image L3.

[0030] The guide image L4 and the shadow L6 are displayed in an animation that moves from bottom to top, making it easier for the user 14 to guide their line of sight and understand the direction. For example, as shown in FIG. 5, when the guide image L4 and the shadow L6 are displayed by moving them to the back (top), the guide image L4 and the shadow L6 are reduced in size as they move. Furthermore, as the display position of the shadow L6 moves to the top, the intensity of the blurring process is increased, thereby emphasizing the sense of perspective. Note that the blurring process can be performed using various image processing methods, such as Gaussian filtering and gradation.

[0031] Such a head-up display comprises a head-up display H that displays an image using a virtual image V in the space ahead of the user 14, a liquid crystal display 20 that projects the image, and a control unit 60 that inputs route guidance information and vehicle information and draws and generates the image that provides route guidance to the user 14 based on this, and the control unit 60 draws and generates the image including a guidance image L4 that indicates the route direction to the destination, and a road surface image L3 that is shown in color to resemble a portion of the vehicle's driving path and has a shadow L6 located below the guidance image L4.

[0032] In addition, the control unit 60 can use perspective to move the display position of the guide image L4 and the corresponding shadow L6 upward, and when the shadow L6 is displayed at the top, it is drawn with a stronger blurring process than when it is displayed at the bottom, thereby emphasizing the sense of perspective and making it easier to understand the positional relationship.

[0033] Furthermore, by displaying the road surface image L3, the control unit 60 can visually recognize the road surface image L3 as a reference (reference plane) position, even though the scenery ahead of the vehicle, which serves as the background, changes, particularly while driving, making it easier to grasp the relative positional relationship of the guide image L4. Furthermore, by displaying grid lines L5 on the road surface, it is possible to express a sense of perspective and distance.

[0034] While the head-up display of the present invention has been described using the configuration of the above-described embodiment as an example, the present invention is not limited thereto, and various improvements and changes to the display are possible in other configurations without departing from the spirit of the present invention. For example, in the above-described embodiment, a liquid crystal display 20 is used as the display device, but a DMD (digital mirror device) or an electromagnetically driven laser beam scanning MEMS mirror may be used as the display device as long as it generates display light containing an image, and the same effects as those of the above-described embodiment can be obtained. Furthermore, the present invention can also be applied to a configuration in which the image is projected onto a dedicated combiner instead of the windshield.

[0035] Furthermore, although the guide image L4 is exemplified as an arrowhead-shaped icon, other shapes can also be used as the guide image as long as they indicate directionality.

[0036] The control unit 60 can also display the color and shape of the lane markings, including the center line, in accordance with the actual road based on the route guidance information. Furthermore, by detecting the position of the user's 14's eyes, the control unit 60 can display the lane markings superimposed on the actual road lane markings.

[0037] Although the example in which the circuit board having the control unit 60 is provided in the display device 12 has been shown, it may also be provided on the side of another vehicle-mounted ECU. In this case, the display device 12 can be realized by a configuration in which a video signal is input via a communication line to cause the liquid crystal display 20 to form an image.

[0038] The present invention relates to a head-up display, and is suitable as a display device that is mounted on a mobile body such as an automobile, a motorcycle, or an agricultural or construction machine, and projects and displays vehicle information, turn-by-turn displays, route guidance such as route guide displays, road information, and the like. [Explanation of symbols]

[0039] 10 vehicles 11. Instrument panel 12 Display device (head-up display) 13 Windshield 14 User (Driver) 20 Liquid crystal display (projection section) L3 Road surface image L4 Guide image L6 shadow part

Claims

1. In a head-up display that displays a virtual image in the space in front of the driver, a projection unit that projects the image; a control unit that receives route guidance information and vehicle information and draws and generates the image that provides route guidance to the driver based on the information; The control unit A guide image showing the route direction to the destination; a road surface image in which a part of the road on which the host vehicle is traveling is shown in color and a shaded area is provided below the guide image; Furthermore, the control unit can blur the outline of the shadow and move the display position of the guide image and the corresponding shadow upward using perspective, and when the guide image is displayed at the top, the shadow is drawn with stronger blurring than when the guide image is displayed at the bottom. Head-up display.

2. The control unit draws the guide image and the shadow portion with a gap therebetween. The head-up display according to claim 1 .

Images