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JP-2026075771-A - Vehicle display device

JP2026075771AJP 2026075771 AJP2026075771 AJP 2026075771AJP-2026075771-A

Abstract

[Problem] To provide a vehicle display device that prevents external light from entering the display unit without driving the reflective mirror. [Solution] The vehicle display device 1 includes a display device 30 that emits a display image projected onto a windshield WS positioned in front of the driver D as display light 11 via a display unit 32, and at least one reflective mirror 20, 21 that reflects the display light 11 in the optical path of the display light 11 from the display device 30 to a reflector. A liquid crystal plate 33 is arranged in the optical path of the display light 11 between the reflective mirrors 20, 21 and the display unit 32, sandwiched between a first polarizing plate 34 and a second polarizing plate 35, and its polarization direction is switched by the application of voltage. The first polarizing plate 34 that transmits one of the polarizations of P-polarization and S-polarization is arranged on the upper surface of the liquid crystal plate 33, and the second polarizing plate 35 that transmits the other of the polarizations of P-polarization and S-polarization is arranged on the lower surface of the liquid crystal plate 33. [Selection Diagram] Figure 2

Inventors

  • 佐野 裕史
  • 高田 良秀
  • 杉浦 祐介

Assignees

  • 矢崎総業株式会社

Dates

Publication Date
20260511
Application Date
20241023

Claims (4)

  1. A display device that projects a display image onto a reflector positioned in front of the vehicle occupant and emits it as display light through a display unit, The optical path of the display light from the display device to the reflector includes at least one reflective mirror that reflects the display light, A liquid crystal plate is positioned between a first polarizing plate and a second polarizing plate in the optical path of the display light between the reflective mirror and the display unit, with the polarization direction being switched by the application of a voltage. A first polarizing plate that transmits one of the polarizations of P-polarized light and S-polarized light is placed on the upper surface of the liquid crystal panel. A vehicle display device comprising a second polarizing plate, which transmits the other polarization of P-polarized light and S-polarized light, arranged on the lower surface of the liquid crystal plate.
  2. The aforementioned at least one reflective mirror comprises a first mirror and a second mirror, The first mirror is a concave mirror, The vehicle display device according to claim 1, wherein the second mirror is a flat mirror or a concave mirror.
  3. A gap is provided in the optical path of the display light between the second polarizing plate and the display unit, as described in claim 1 or 2 for a vehicle display device.
  4. A buffer member is arranged around the optical path of the display light between the second polarizing plate and the display unit, as described in claim 3.

Description

This invention relates to a vehicle display device. Some vehicles, such as automobiles, are equipped with a vehicle display device, also known as a head-up display (HUD) (see Patent Document 1). A vehicle display device comprises a display unit (image display device) that generates and outputs display light, a reflective mirror that reflects the display light emitted from the display unit toward a projection unit (a reflector positioned in front of the vehicle occupant), and a housing that houses the display unit and the reflective mirror. This vehicle display device is configured to project the display image shown by the display unit onto the aforementioned projection unit (reflector) via the reflective mirror, etc., so that the driver can perceive it as a virtual image. Japanese Patent Publication No. 2024-007661 This is a schematic diagram showing an example of a vehicle equipped with a vehicle display device according to this embodiment.This is a schematic diagram showing an example of a vehicle display device according to this embodiment.This is a perspective view of the display device.This is a side view of the display device.This is a schematic diagram showing the liquid crystal panel sandwiched between the first polarizing plate and the second polarizing plate.Figure 4 is an enlarged view showing the top surface of the display device.This is a schematic diagram showing how ambient light passes through a liquid crystal panel when no voltage is applied to it.This is a schematic diagram showing how ambient light is transmitted through a liquid crystal panel when a voltage is applied to it.This is a schematic diagram showing an example of a vehicle display device according to this embodiment.This is a schematic diagram showing how ambient light enters the top surface of a conventional vehicle display device.This is a schematic diagram showing how ambient light enters the top surface of a display device.This is a schematic diagram showing how ambient light enters the top surface of a display device. The vehicle display device according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from actual ratios. As shown in Figure 1, the vehicle display device 1 according to this embodiment is a head-up display device mounted in a vehicle 100, such as an automobile. The vehicle display device 1 is positioned inside the dashboard 101 together with the meter 103 and displays a virtual image V in front of the eye point EP of the vehicle 100. The eye point EP is a predetermined position as the viewpoint of a vehicle occupant (driver D) seated in the driver's seat. The vehicle display device 1 is located inside the dashboard 101 of the vehicle 100. An upper opening 101a is provided on the upper surface of the dashboard 101. The vehicle display device 1 projects a display image onto the windshield WS through this upper opening 101a. The windshield WS is a reflector located in front of the driver D in the vehicle 100. The windshield WS is, for example, semi-transparent and reflects light incident from the vehicle display device 1 toward the eye point EP. The driver D perceives the image reflected by the windshield WS as a virtual image V. The driver D perceives the virtual image V as being located in front of the windshield WS. As shown in Figure 2, the vehicle display device 1 according to this embodiment comprises reflective mirrors 20 and 21, a display device 30, a control unit 40, and a housing 50. The housing 50 is, for example, made of a synthetic resin material molded into a box shape, and has an internal space. The housing 50 houses and holds the reflective mirrors 20, 21, the display device 30, and the control unit 40 within its internal space. The housing 50 has an opening 60 that connects the outside of the housing 50 to the internal space. This opening 60 is located on the upper wall of the housing 50, facing the windshield WS. Furthermore, a cover member 61, made of a translucent synthetic resin material (e.g., acrylic resin), is provided on the upper wall of the housing 50 to close the opening 60. The vehicle display device 1 emits display light 11 from the housing 50 through the opening 60 toward the windshield WS. The display light 11 is light emitted from the display device 30 and reflected by the reflective mirrors 20, 21. The control unit 40 is electrically connected to the display device 30 and controls the display of the display image (virtual image V) displayed by the vehicle display device 1. This control unit 40 is composed of, for example, an IC chip and is powered by electricity obtained from the battery in the vehicle 100. The control unit 40 may also be connected to the ECU (Electronic Control Unit) in the vehicle 100 and may transmit and receive signals with the ECU. The display device 30 emits the display image projected onto the windshield WS as disp