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EP-4737795-A1 - LIGHT PROJECTION SYSTEM FOR A VEHICLE

EP4737795A1EP 4737795 A1EP4737795 A1EP 4737795A1EP-4737795-A1

Abstract

The invention concerns a light projection system (100) for a vehicle, comprising a light source unit (110) and a primary lens (120). The light source unit (110) comprises a light emitting surface emitting light beams (200) comprising direct light beams (210) and diffused light beams (220). The primary lens (120) comprises an optical axis (D), a light-entry lens surface (121) facing the light source unit (110) and a light-exit lens surface (122). The light-entry lens surface (121) comprises at least one non-transparent region (123) and at least one transparent region (124). The non-transparent region (123) is configured to block the diffused light beams (220) without the need of an additional shield placed at a distance from the light-entry lens surface (121) and to let direct light beams (210) entry the light-entry lens surface (121) through the transparent region (124).

Inventors

  • CHMELA, RADEK
  • GUZEJOVA, Ester

Assignees

  • PO LIGHTING CZECH s.r.o.

Dates

Publication Date
20260506
Application Date
20241031

Claims (15)

  1. A light projection system (100) for a vehicle, comprising - a light source unit (110), comprising a light emitting surface emitting light beams (200) comprising direct light beams (210) and diffused light beams (220), - a primary lens (120) comprising an optical axis (D), a light-entry lens surface (121) facing the light source unit (110) and a light-exit lens surface (122), characterized in that the light-entry lens surface (121) comprises at least one non-transparent region (123) and at least one transparent region (124), the non-transparent region (123) being configured to block the diffused light beams (220) without the need of an additional shield placed at a distance from the light-entry lens surface (121) and to let direct light beams (210) entry the light-entry lens surface (121) through the transparent region (124).
  2. The light projection system (100) for a vehicle according to claim 1, wherein the non-transparent region (123) of the light-entry lens surface (121) at least partially shields sun rays (300) which enters into the light projection system (100) through the light-exit lens surface (122), towards the light source unit (110).
  3. The light projection system (100) for a vehicle according to claim 1 or 2, wherein the light-entry lens surface (121) has an integrated non-transparent layer in the non-transparent region (123).
  4. The light projection system (100) for a vehicle according to claim 3, wherein the integrated non-transparent layer of the non-transparent region (123) of the light-entry lens surface (121) is formed by surface treatment, with or without adding material to the light-entry lens surface (121), such as painting, graining, metallization, grain structure formation, laser burning or molding.
  5. The light projection system (100) for a vehicle according to claim 3 or 4, wherein edges of the non-transparent layer of the non-transparent region (123) of the light-entry lens surface (121) are not perceptible.
  6. The light projection system (100) for a vehicle according to any one of the preceding claims, wherein the transparent region (124) is positioned in the center of the light-entry lens surface (121).
  7. The light projection system (100) for a vehicle according to any one of the preceding claims, wherein once the light projection system (100) is installed on the vehicle, the non-transparent region (123) is positioned on top and/or bottom of the light-entry lens surface (121) when the vehicle is oriented in its usual upright position.
  8. The light projection system (100) for a vehicle according to claim 7, wherein the non-transparent region (123) on top and/or bottom extends the full width of the light-entry lens surface (121) when the vehicle is oriented in its usual upright position.
  9. The light projection system (100) for a vehicle according to any one of the preceding claims, wherein once the light projection system (100) is installed on the vehicle, the non-transparent region (123) is positioned on at least one of vertical sides of the light-entry lens surface (121) when the vehicle is oriented in its usual upright position.
  10. The light projection system (100) for a vehicle according to any one of the preceding claims, comprising at least two lenses (120, 140, 160), including the primary lens (120), wherein the at least two lenses (120, 140, 160) are arranged along a direction of the optical axis (D) of the primary lens (120).
  11. The light projection system (100) for a vehicle according to any one of the preceding claims, comprising a lens holder (130) extending along the direction of the optical axis (D) of the primary lens (120), with the primary lens (120) or the at least two lenses (120, 140, 160) being fixed to the lens holder (130).
  12. The light projection system (100) for a vehicle according to any one of the preceding claims, wherein the light source unit (110) comprises at least one light-emitting diode.
  13. The light projection system (100) for a vehicle according to any one of the preceding claims, wherein the light source unit (110) comprises at least one micro light-emitting diode.
  14. The light projection system (100) for a vehicle according to claim 13, wherein the light source unit (110) comprises an array of multiple-row and/or multi-column micro light-emitting diodes.
  15. A vehicle, characterized in that it comprises at least one light projection system (100) according to any one of claims 1 to 14.

Description

FIELD OF THE INVENTION The present invention relates to the field of vehicle lighting system, particularly relates to the light projection systems for vehicles. BACKGROUND OF THE INVENTION Various vehicle lighting systems are known in the prior art to produce an illuminating beam, a signaling beam, or a combination of both. In conventional designs, vehicle lighting systems are used to enhance visibility and safety by providing clear and bright illumination for drivers and pedestrians. These systems are critical in ensuring effective communication of vehicle intentions and improving overall road safety. However, regulation on road illumination becomes more and more strict regarding areas that should be covered by the beams and areas that should remain in the dark so as to prevent any risk of glare of an opposite road user. This antagonistic requirement can become all the more difficult to meet as the light intensity threshold is set to a high level in illuminated areas. Hence, precise and high-contrast projections of beams, free of artefacts and halo effects, are often appreciated as a valuable feature of the lighting system for its ability to meet high standard requirements. Therefore, there is a need to reduce the artefacts and halo effects in the projections on the road, in order to improve the quality of the illumination, while meeting high standard requirements regarding illuminated and non-illuminated areas of the road. The need becomes even more critical when the light system is used for displaying images, symbols, and creating shadowing effects on road surfaces or to open areas, such as using Matrix High Beam (MHB) technology. Recent advancements in lighting technology have led to the development of high-resolution projection systems capable of displaying images, symbols or shadows on road surfaces or to open areas. For example, this capability is particularly beneficial for advanced driver assistance systems (ADAS), which rely on precise and high-contrast projections to convey important information to drivers. However, the existing light projection systems, which use for example Light Emitting Diode (LED) as light sources, including traditional LED and micro-LED (µLED), such as multi-row or/and multi-column LED or µLED arrays, face challenges in meeting the requirements of precise and high-contrast projections on road surfaces or to open areas, whether for illumination purposes or for displaying images, symbols, or creating shadowing effects. There are two main issues to address. Firstly, the diffused light rays emitted from the light sources interact with the primary lens, resulting in the degradation of contrast and clarity of the projections, such as projected images, on the road. This interaction, caused by the diffused light, creates unwanted artefacts including halo effects in the projections on the road. These artefacts are even more significant when the multi-row or/and multi-column LED or µLED arrays are used as light sources. In particular, the µLEDs are used because they offer several advantages, including superior brightness, color accuracy, and the ability to produce high-resolution images and shadowing effects. The µLEDs can be densely packed into a small area, making them ideal for applications requiring detailed and clear projections. However, due to their small size and high packing density, µLEDs generated more diffused or/and parasitic light compared to traditional LEDs. Therefore, the light projection system using µLEDs has a greater need to address artefacts including halo effects compared to traditional light projection system. In addition, more than one lens is often used in a light projection system. This accentuates the artefacts and halo effects in the projections on the road. Secondly, another issue is the susceptibility of the light sources, such as LED chips, to be damaged by sunlight. This sunlight is commonly referred to as "sunload". This is because the sun rays could go through the lens of the light projection system and reach, or even focus on, the light sources. Exposure to intense sunlight can not only affect the performance of the LEDs but also potentially damage the chips, reducing their lifespan and reliability. To reduce the sunload on the light sources of the light projection system, existing designs have introduced additional components within the light projection system. These typically involve the use of additional parts, such as metal sheet or other materials, that serve as shields or shutters placed between the light sources and the primary lens. These shields are designed to partially block sun rays to reach the light sources. However, the additional components, such as metal shields, are positioned at a distance from the lens, due to assembly constraints. Their non-negligible thickness introduces a first disadvantage, as it can cause unwanted artefacts in the projections. Secondly, their position relative to the lens often creates additional unwanted a