WO2020012231A1

WO2020012231A1 - Head-up display assembly and manufacturing method thereof

Info

Publication number: WO2020012231A1
Application number: PCT/IB2018/055213
Authority: WO
Inventors: Rui Nuno BARROS; Aníbal Jorge FERNANDES PORTINHA; Pedro Miguel FERREIRA MONTEIRO; João Miguel CASTRO MARQUES
Original assignee: Bosch Car Multimedia Portugal S.a.
Priority date: 2018-07-11
Filing date: 2018-07-13
Publication date: 2020-01-16

Abstract

A head-up display assembly, and manufacturing method thereof, comprising a display combiner, a support for the display combiner and a bonding layer fixing the display combiner to said support on a bonding region of said support, wherein the support comprises a plurality of curved-surface protrusions in said bonding region for maintaining a gap for receiving the bonding layer between the support and the display combiner. The protrusions can be hemi-spheres and are distributed along said bonding region. The gap can be constant along said bonding region and the protrusions are arranged to maintain a height of said gap such that shape deviations of the combiner display are prevented. The support may comprise lateral pads arranged laterally to said bonding region having a protrusion height lower than the bonding layer height. The protrusions may be arranged in pairs, said pairs being located along the bonding region.

Description

D E S C R I P T I O N

HEAD-UP DISPLAY ASSEMBLY AND MANUFACTURING METHOD THEREOF

Technical field

[0001] The present disclosure relates to a head-up display device, HUD, for automotive industry, especially for motor vehicles. In particular, the disclosure relates to a HUD with a retractable display to be coupled to an instrument panel and configured to display a vehicle information, navigation information among other relevant data.

Background

[0002] Head-up-display systems, HUDs, are nowadays largely used in the automotive industry. There are different types of HUDs: Combiner head-up display, C-HUD, Augmented Reality head-up display, AR-HUD, and windshield head-up display, W-HUD.

[0003] The AR-HUD systems are complex and the information is typically projected into a larger region of the windshield. These systems generate a virtual image projection and allow an interaction with the real scenario in front of the driver.

[0004] The W-HUD systems are quite similar to the C-HUD, but in this case the projection is made on a smaller region of the windshield instead of using an independent reflection or display element.

[0005] Most head-up display devices, for example document WO2015115218A1 discloses a head-up display configured with a combiner, a support base that supports the combiner, an image projection means that projects an image to the combiner, and a housing that has an attachment groove. Similarly, documents EP3232249A1, DE102015225122A1 and WO2016167687A1 also disclose head-up display devices with various fixing means.

[0006] Document DE102016200902 discloses a display device for a vehicle and a mounting unit for mounting the display device to a fitting portion of the vehicle, and at least one fixing member for fixing the screen means to the fitting portion. [0007] The C-HUD systems are generally composed by a reflection or display/combiner unit, a picture generate unit, a kinematic mechanism and a cover. The reflection or display/combiner element unit is composed by a support and a translucent display, where the information is projected for driver's visualization. The HUD systems allow the drivers to view important data like for example, speed, GPS indications, fuel consumptions, among others, without taking their eyes from the road. In the systems with display/combiner (C-HUD) the information is projected to the driver as a virtual image where the display/combiner element plays the most important role. C-HUD systems normally need to have the display/combiner fixed to a support assembled into a kinematic mechanism.

[0008] These facts are disclosed in order to illustrate the technical problem addressed by the present disclosure.

General Description

[0009] The present disclosure relates to a head-up display device (HUD) for automotive industry, especially for motor vehicles. In particular, the disclosure relates to a HUD with a retractable display to be coupled to an instrument panel and configured to display vehicle information, navigation information among other relevant data.

[0010] The disclosure is advantageous in providing a fixation system that is simple and uses few parts. The disclosed fixation is cost-effective, simple to assemble and avoids shape deviations causing distortions in the final image projected to the driver. The disclosure also allows to control bonding material to overflow to the display/combiner optical region when bonding layers are used.

[0011] It is disclosed a head-up display assembly comprising:

a display combiner, a support for the display combiner and a bonding layer fixing the display combiner to said support on a bonding region of said support, wherein the support comprises a plurality of curved-surface protrusions in said bonding region for maintaining a gap for receiving the bonding layer between the support and the display combiner.

[0012] The protrusions are implemented to improve the correct positioning of the display combiner when fixed to the support by the bonding layer.

[0013] In an embodiment, the curved-surface protrusions are hemi-spheres.

[0014] The plurality of hemi-spheres is implemented and arranged on the support bonding region for controlling the torsion and curvature of the display/combiner shape during the fixation.

[0015] In an embodiment of the head-up display, the protrusions are distributed along said bonding region.

[0016] In an embodiment, the gap is constant along said bonding region.

[0017] In an embodiment, the protrusions are arranged to maintain a height of said gap such that shape deviations of the combiner display by shrinkage of the bonding layer during fixation are prevented.

[0018] In an embodiment, the support comprises lateral pads arranged laterally to said bonding region having a protrusion height lower than the bonding layer height.

[0019] In an embodiment, the protrusions are arranged in pairs, said pairs being located along the bonding region.

[0020] In an embodiment, the support comprises a groove arranged throughout the length of the bonding region to prevent the overflow of the bonding layer along the display combiner.

[0021] In an embodiment, the groove is arranged in a top part of the support.

[0022] In an embodiment, the maximum depth of the groove is equal to the maximum thickness of the bonding layer and the length of the groove is equal to the distance between the lateral pads. [0023] In an embodiment, the display combiner comprises openings and the support comprise guide pins for cooperating with said openings for guiding the positioning of the display combiner during fixation to said support.

[0024] In an embodiment, the bonding layer is a photo sensitive curable bonding layer.

[0025] In an embodiment, the display combiner is transparent in the bonding region such that light passing through the display combiner is able to cure the photo sensitive curable bonding layer.

[0026] It is also described a method for manufacturing an automotive head-up display assembly comprising a display combiner and a support for the display combiner, said support comprising a plurality of curved-surface protrusions in a bonding region, said method comprising the steps of: providing the display combiner and the support for the display combiner; applying a bonding layer fixing the display combiner to said support on a bonding region of said support; assembling the support and the display combiner with said protrusions maintaining a gap between the support and the display combiner with the bonding layer.

Brief Description of the Drawings

[0027] The following figures provide preferred embodiments for illustrating the description and should not be seen as limiting the scope of disclosure.

[0028] Figure 1 shows a schematic representation of an embodiment of the complete display/combiner unit for a C-HUD system (isometric view).

[0029] Figure 2 shows a schematic representation of an embodiment of the complete display/combiner unit for a C-HUD system (cross-section).

[0030] Figure 3 shows a schematic representation of an embodiment of the display/combiner support with guide pins, lateral pads and hemi-spheres (isometric view). [0031] Figure 4 shows a schematic representation of an embodiment of the display/combiner support with bonding layer, hemi-spheres and groove (isometric view).

[0032] Figure 5 shows a schematic representation of an embodiment of the display/combiner unit cross-section (cross-section).

[0033] Figure 6 shows a schematic representation of an embodiment of the display/combiner support with bonding layer, hemi-spheres and groove (isometric view), showing the driver's image impact for torsion in Figure 6(a) and for curvature in Figure 6(b), in terms of distortion 10, trapeze 11, magnification 12, and aspect ratio 13.

Detailed Description

[0034] The main goal of this patent is related with the development of a new solution for Combiners Head UP Displays (CHUD's) and Head UP Displays (HUD's), in particular to develop a new solution of fixation regarding critical parts, like the fixation of display/combiner on the display/combiner support.

[0035] The present disclosure comprises a fixation system for combiner and/or other displays to the combiner support that will be coupled to the kinematics of the C-HUD. The fixation system comprises a display/combiner bonded only from one side and no screws, springs or display/combiner cover are used. The disclosure brings an improvement in the overflow of the bonding layer to the display/combiner optical region with the implementation of a groove in the display/combiner support. At the same time the current disclosure improves, with the implementation of guide pins and alignment hemi-spheres, the capacity of alignment and influence of the shrinking of the bonding layer in distortions (Figure 6) of the display/combiner that will affect the quality of the driver's projected image.

[0036] In C-HUD systems the fixation of the display/combiner to the display/combiner support is a complex process since small shape deviations (Figure 6) can be induced in the display/combiner having impact in the optical quality of the image projected to the driver. [00B7] Display/Combiner fixation should also guaranty a good adhesion of the display/combiner to the support when exposed to a specific misuse force, specific temperature exposure and during the product lifetime.

[0038] The display/combiner unit is composed by the display/combiner, support and a bonding layer as fixation system. The combiner as an optical element is very sensitive to small shape deviations, caused by the parts to which is being fixed and also by the bonding shrinkage used to fix it to the support. These shape deviations of the combiner lead to image distortions in the virtual image (Figure 6). The different parts of the combiner unit should be manufactured taking into account close tolerances. However, the need for so demanding tolerances has the immediate effect of increasing the costs associated with the manufacturing.

[0039] The design of these parts usually requires a very careful design to ensure excellent quality parameters. Most of the time, the most important technical specifications for the combiner unit are related with surface tolerances and mechanical stability.

[0040] The present disclosure comprises a display/combiner 1, a display/combiner support 2 and a bonding layer 3. The display/combiner is fixed to the support with a bonding layer applied directly on the support. The combiner support is design to guaranty mechanical stability and minimum surface deviations. Guide pins 4, lateral pads 5 and hemi-spheres 6 are implemented on the display/combiner support to guaranty the correct positioning of the display/combiner and control its shape deviations induced by shrinkage of the bonding layer during the curing process. A groove 8 is also implemented in the display/combiner support to control the bonding layer overflow to the display/combiner optical region. The display/combiner is bonded with the display/combiner support with a photo sensitive bonding layer where the light pass through the display/combiner in order to perform the cure. Display/combiner shape deviations due to the curing process of the bonding layer and the adhesion strangeness are also controlled by means of the bonding layer pattern, distance to the curing source and also the time of curing. [0041] Figure 1 and Figure 2 depicts an isometric and cross-section view of the complete display/combiner unit suitable to be used in C-HUD systems. The unit is composed by a display/combiner 1, a display/combiner support 2, and a bonding layer 9 shown in Figure 5. One of the most relevant components of this fixation mechanism is the combiner support. One of the advantages to use only a combiner support without a cover or fixation screws is the reduction of parts involved in the process, bringing to less weight and complexity of the display/combiner unit and also to a less complex and fast assembling process.

[0042] Figure 3 depicts an isometric view of the combiner support with the bonding disposal region 3, guide pins 4, lateral pads 5 and hemi-spheres 6. Guide pins and lateral pads are responsible to ensure the correct positioning of the combiner before and during the bonding curing process.

[0043] The hemi-spheres 6 are responsible to control the torsion and curvature of the combiners shape (Figure 6) during the bonding curing process. Hemi-spheres are implemented on the combiner support bonding disposal region 3, between or outside the lateral pads 5. The number of hemi-spheres to be implemented depends of the overall size and thickness of the display/combiner unit. The height of the hemi-spheres varies to a maximum of the height of the lateral pads 5

[0044] The lateral pads 5 are responsible for placing the display/combiner into the display/combiner support and are placed close to the lateral limits of the display/combiner support like shown in the Figure 3. The lateral pads height varies to a maximum of the height of the bonding layer.

[0045] The guide pins 4 are responsible to align the display/combiner into the display/combiner support during the fixation process and are implemented in the bonding region of the display/combiner support.

[0046] Figure 4 and Figure 5 presents a combiner support with the groove 8, bonding region 7 plus the bonding layer 9. In a preferable embodiment, the bonding layer gap 14 is 0.4 mm to 0.6mm thick, in particular 0.5mm thick. [0047] Combiner shape deviations due to the curing process of the bonding layer and the adhesion strangeness are controlled by means of the lateral pads 5 and hemi spheres 6 but also by the boding layer pattern, distance to the curing source and curing time. During the fixation process when the display/combiner is pressed to the display/combiner support the bonding layer can overflow to the combiner optical region. The groove 8 is implemented to avoid the bonding layer to overflow to the combiner optical region and is placed in the top or/and lateral region of the display/combiner support bonding region 7 and the width is equal to the distance between the lateral pads 5. The maximum depth of the groove is equal to the maximum thickness of the bonding layer.

[0048] For the definition of the amount and position of hemi-spheres, it was considered the distance between the lateral contact pads, the momentum that could be interrupted by these spheres (momentum caused by the bounding material shrinkage effect, responsible for causing optical defects at the combiner/display) and in addition according to the allowed optical tolerances.

[0049] The term "comprising" whenever used in this document is intended to indicate the presence of stated features, integers, steps, components, but not to preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0050] It will be appreciated by those of ordinary skill in the art that unless otherwise indicated herein, the particular sequence of steps described is illustrative only and can be varied without departing from the disclosure. Thus, unless otherwise stated the steps described are so unordered meaning that, when possible, the steps can be performed in any convenient or desirable order.

[0051] The disclosure should not be seen in any way restricted to the embodiments described and a person with ordinary skill in the art will foresee many possibilities to modifications thereof. The above described embodiments are combinable. The following claims further set out particular embodiments of the disclosure.

Claims

C L A I M S

1. Head-up display assembly comprising:

a display combiner (1), a support for the display combiner (2) and a bonding layer (9) fixing the display combiner (1) to said support (2) on a bonding region (3) of said support (2),

wherein the support (2) comprises a plurality of curved-surface protrusions (6) in said bonding region (3) for maintaining a gap for receiving the bonding layer (9) between the support (2) and the display combiner (1).

2. Head-up display assembly according to the previous claim wherein the protrusions (6) are hemi-spheres.

3. Head-up display assembly according to any of the previous claims wherein the protrusions (6) are distributed along said bonding region.

4. Head-up display assembly according to the previous claim wherein the protrusions (6) are arranged in pairs, said pairs being located along the bonding region (3).

5. Head-up display assembly according to any of the previous claims wherein said gap is constant along said bonding region (3).

6. Head-up display assembly according to any of the previous claims wherein the protrusions (6) are arranged to maintain a height of said gap such that shape deviations of the combiner display (1) by shrinkage of the bonding layer during fixation are prevented.

7. Head-up display assembly according to any of the previous claims wherein said support (2) comprises lateral pads arranged laterally to said bonding region having a protrusion height lower than the bonding layer height.

8. Head-up display assembly according to any of the previous claims wherein said support (2) comprises a groove (7) arranged throughout the length of the bonding region to prevent the overflow of the bonding layer (3) along the display combiner (1).

9. Head-up display assembly according to the previous claim wherein the groove (7) is arranged in a top part of the support (2).

10. Head-up display assembly according to any of the previous claims wherein the display combiner (1) comprises openings and the support (2) comprises guide pins (4) for cooperating with said openings for guiding the positioning of the display combiner (1) during fixation to said support (2).

11. Head-up display assembly according to any of the previous claims wherein the bonding layer (3) is a photo sensitive curable bonding layer (9).

12. Head-up display assembly according to the previous claim wherein the display combiner (1) is transparent in the bonding region such that light passing through the display combiner (1) is able to cure the photo sensitive curable bonding layer (9).

13. A method for manufacturing an automotive head-up display assembly comprising a display combiner (1) and a support for the display combiner (2), said support comprising a plurality of curved-surface protrusions (6) in a bonding region (3), said method comprising the steps of:

providing the display combiner (1) and the support (2) for the display combiner; applying a bonding layer (3) fixing the display combiner (1) to said support on a bonding region (3) of said support (2);

assembling the support (2) and the display combiner (1) with said protrusions (6) maintaining a gap between the support (2) and the display combiner (1) with the bonding layer (3).