TWI845609B - Electronic display system and production method thereof - Google Patents

Abstract

The electronic display system includes a display screen having a flat display surface; and an optical lens arranged in front of the display surface and having a front surface and a back surface. The optical lens is formed by a plurality of optical layers superposed on each other, and the plurality of optical layers include a front optical layer defining the front surface and a rear optical layer defining the rear surface, and the optical layers are made of a replication template.

Description

Electronic display system and manufacturing method thereof

The present invention relates to an electronic display system including an image display screen and an optical lens and a manufacturing method thereof.

The electronic display system may be arranged in a vehicle, in particular a motor vehicle, for example. The image display screen may include an array of picture elements, which are individually controlled by a graphics controller for displaying different images.

In motor vehicles, for example for aesthetic reasons and in order to integrate the image display in the interior cladding of the motor vehicle, the image display can be arranged behind an optical lens, for example in the instrument panel, the headrest, the center console or the like.

The optical lens has a front surface on the opposite side of the image display screen, for example. The front surface is non-planar, that is, three-dimensional, conforming to the desired shape.

It is contemplated that the image generated by the image display screen is visible through the lens in an appropriate manner.

The object of the present invention is to provide an electronic display system that can satisfy the requirements of simple and economical manufacturing.

To this end, the present invention proposes an electronic display system, including a display screen and an optical lens. The display screen is configured to display images on a planar display surface, and the optical lens is arranged in front of the display surface so that the display surface is visible through the optical lens. The optical lens has a curved front surface on the side opposite to the display surface and a rear surface on the side of the display surface, wherein the optical lens is formed by multiple optical layers superimposed on each other, the multiple optical layers include a front optical layer defining the front surface and a rear optical layer defining the rear surface, and the optical layers are made using a replica template.

In a specific embodiment, the electronic display system includes one or more of the following optional features, which are adopted alone or in any technically possible combination:

- the front surface of the optical lens is convex and/or concave;

- The anterior optic has a curved rear surface;

- The rear surface of the anterior optic is convex and/or concave;

- The rear surface of the optical lens is flat and parallel to the display surface of the display screen;

- An optical lens consists of exactly two optical layers, the front optical layer and the back optical layer;

- at least two optical layers are made of the same material;

- at least two optical layers are made of different materials;

- the rear surface of the optical lens is spaced from the display surface;

- The system comprises a light coupling layer interposed between the display surface of the display screen and the back of the optical lens;

- The system consists of a touch film inserted between two optical layers that are superimposed and molded.

The present invention also relates to a manufacturing method for manufacturing the above-mentioned display system, comprising: obtaining an optical lens by molding an optical layer, and arranging the optical lens in front of a display screen, wherein the rear surface of the optical lens is parallel to the display surface of the display screen.

In a specific embodiment, the manufacturing method includes one or more of the following optional features, which are adopted alone or in any technically possible combination:

- The method comprises: optically coupling the display screen and the optical lens through an optical coupling layer interposed between a rear surface of the optical lens and a display surface of the display screen;

- A light coupling layer is inserted between the display surface of the display and the back of the optical lens;

- The method comprises: applying a touch film on the pre-molded optical layer before making an additional optical layer on the pre-molded optical layer using a replica template during molding of the optical lens, so that the touch film is interposed between the pre-molded optical layer and the additional optical layer.

The electronic display system 10 in Fig. 1 can be installed in a vehicle, in particular a motor vehicle, for example. Here, the electronic display system 10 is fixed to a support 12 of a cladding 14. The cladding 14 is, for example, an inner cladding of the vehicle.

The envelope 14 is, for example, a dashboard of a motor vehicle. In a variant, the interior envelope is a center console, a seat back, a headrest, a partition, a workbench, a control console, etc.

The electronic display system 10 includes a display screen 16 configured to display images.

The display screen 16 is configured to generate images and display the images on a display surface 16A of the display screen 16 .

The display screen 16 is formed, for example, by a matrix of picture elements. Each picture element of the display screen 16 is used to emit light. Preferably, each picture element is controlled separately by a graphics controller so that the display screen 16 can display different images, especially dynamic images. Dynamic images are a set of fast static images for displaying actions.

The display 16 is, for example, an electroluminescent screen, in particular a light emitting diode (LED) screen, in particular an organic light emitting diode (OLED) screen. In a variant, the display is a liquid crystal screen (LCD).

The display screen 16 is advantageously an active matrix screen. Such a display screen has an active matrix. The active matrix comprises one or more dedicated to each picture element of the display screen and is capable of controlling each picture element separately. The active matrix is, for example, of the thin film transistor (TFT) type. The active matrix screen 16 can be an active matrix organic light emitting diode (AMOLED) screen or an active matrix liquid crystal display (AMLCD).

In this case, the display screen 16 is fastened to a support element 12 of an inner cladding 14 of the vehicle.

The display surface 16A of the display screen 16 is preferably planar.

The electronic display system 10 includes an optical lens 18. The optical lens 18 is disposed in front of the display screen 16 so that a display surface 16A of the display screen 16 is visible to a user through the optical lens 18.

The optical lens 18 has a front surface 18A on the opposite side of the display surface 16A of the display screen 16 and a rear surface 18B on the display surface 16A side of the display screen 16. The front surface 18A of the optical lens 18 is a surface visible to a user who is viewing the display screen 16 through the optical lens 18.

The front surface 18A of the optical lens 18 is curved. The front surface 18A of the optical lens 18 is therefore three-dimensional, i.e. non-planar. The front surface 18A of the optical lens 18 is convex here. In a variant, the front surface 18A of the optical lens 18 can be concave. In another variant, the front surface 18A of the optical lens 18 is concave and convex, that is, has at least one concave area and at least one convex area.

The curved front surface 18A of the optical lens 18 enables adaptation to a desired shape of the electronic display system, for example for aesthetic reasons and/or integration in the envelope 14.

The rear surface 18B of the optical lens 18 is flat and parallel to the display surface 16A of the display screen 16.

The optical lens 18 is made of a plurality of optical layers 20, 22. The optical lens 18 has a plurality of optical layers 20, 22 overlapped between a front surface 18A and a rear surface 18B. The optical lens 18 includes a front optical layer 20 defining a front surface 18A of the optical lens 18, and a rear optical layer 22 defining a rear surface 18B of the optical lens 18.

Each optical layer 20, 22 of the optical lens 18 includes a front face 20A, 22A facing the front surface 18A of the optical lens 18, and a rear face 20B, 22B facing the rear surface 18B of the optical lens 18.

The optical layers 20, 22 of the optical lens 18 are obtained by molding, the optical layers 20, 22 being produced using replicated templates to obtain the optical lens 18. Each pair of optical layers 20, 22 of the optical lens 18 comprises optical layers produced using templates and superimposed on each other.

As shown in FIG. 1 , the optical lens 18 , for example, comprises exactly two overlapping optical layers 20 , 22 , namely a front optical layer 20 and a rear optical layer 22 .

One of the front optical layer 20 and the rear optical layer 22 is fabricated on the other using a replica template.

In one embodiment, the rear optical layer 22 is made on the rear surface 20B of the pre-molded front optical layer 20 using a replica template. In a variant, the front optical layer 20 is made on the front surface 22A of the pre-molded rear optical layer 22 using a replica template.

The interface between at least two adjacent optical layers 20, 22 of the optical lens 18 is three-dimensional, ie non-planar, and in particular curved.

In one embodiment, the rear surface 20B of the front optical layer 20 is, for example, concave, and the front surface 22A of the adjacent rear optical layer 22 is convex. In a variation, the rear surface 20B of the front optical layer 20 is convex, and the front surface 22A of the adjacent rear optical layer 22 is concave. In another variation, the rear surface 20B of the front optical layer 20 is concave and convex, that is, includes at least one concave area and at least one convex area, and the front surface 22A of the adjacent rear optical layer 22 is convex and concave correspondingly.

When the optical lens exactly comprises two optical layers molded on top of each other as shown in FIG. 1 , the rear surface 20B of the front optical layer 20 and the front surface 22A of the rear optical layer 22 are complementary.

In the embodiment shown in FIG. 1 , the interface between the front optical layer 20 and the rear optical layer 22 is three-dimensional, and in particular, curved.

The rear surface 20B of the front optical layer 20 and the front surface 22A of the rear optical layer 22 are curved. The rear surface 20B of the front optical layer 20 is convex, and the front surface 22A of the rear optical layer 22 is concave.

Advantageously, the optical lens 18 comprises at least two adjacent optical layers 20, 22 molded one above the other using the same material.

This enables adhesion between the two optical layers 20, 22 and good optical coupling between the two optical layers 20, 22.

In a variation or alternatively, the optical lens 18 comprises at least two optical layers molded one on top of the other using different materials.

In the embodiment shown in Figure 1, the optical lens preferably comprises exactly two optical layers 20, 22 molded one over the other using the same material. In a variant, the two optical layers 20, 22 use different materials.

Each optical layer 20, 22 is made of, for example, polycarbonate (PC) or polymethyl methacrylate (PMMA).

The optical lens 18 is spaced apart from the display surface 16A of the display screen 16. More specifically, the rear surface 18B of the optical lens 18 is spaced apart from the display surface 16A of the display screen 16.

The rear surface 18B of the optical lens 18 is not in direct contact with the display surface 16A of the display screen 16.

The electronic display system 10 includes a light coupling layer 24 interposed between the display surface 16A of the display screen 16 and the rear surface 18B of the optical lens 18 .

The light coupling layer 24 is made of light transparent material.

The light coupling layer 24 is formed to fill the space between the display surface 16A of the display screen 16 and the rear surface 18B of the optical lens 18 so that the space is not empty.

The light coupling layer 24 contacts the display surface 16A of the display screen 16 and the rear surface 18B of the optical lens 18.

The light coupling layer 24 acts as a light guide between the display surface 16A of the display screen 16 and the rear surface 18B of the optical lens 18.

The light coupling layer 24 is preferably configured to have a continuous optical index with the optical lens 18 and particularly with the rear optical layer 22.

Therefore, in a preferred embodiment, the optical index of the light coupling layer 24 is substantially equal to the optical index of the rear optical layer 22.

“Substantially equal to” means that the optical index of the light coupling layer 24 is within a range of 10%, specifically 5%, of the optical index of the rear optical layer 22.

In a preferred embodiment, the optical layers 20, 22 have substantially the same optical index.

The light coupling layer 24 is made of photogel.

The light coupling layer 24 is molded, for example, between the display surface 16A of the display screen 16 and the rear surface 18B of the optical lens 18.

Optionally, the display screen 16 is optionally a touch display screen, and the user's touch interaction on the display surface 16A of the display screen 16 enables input of instructions, such as pointing to a graphic object (e.g., a button, a cursor, etc.) in the image displayed on the display surface 16A of the display screen 16.

Touch interaction with the display screen 16 is accomplished, for example, through the optical lens 18 and, if necessary, optionally through the light coupling layer 24.

Optionally, as shown in FIG. 2 , the electronic display system 10 includes a light-transparent touch film 26 inserted between the two optical layers 20 , 22 of the optical lens 18 .

The touch film 26 is configured to enable a user to perform touch interaction with the electronic display system 10 by touching the front surface 18A of the optical lens 18 , such as pointing to an active graphic object (eg, a button, a cursor, etc.) in the graphics displayed on the display screen 16 .

Preferably, one of the two optical layers 20 and 22 with the touch film 26 inserted therein is fabricated on the other using a replica template, and the touch film 26 is inserted between the two optical layers 20 and 22.

In a variation not shown, the touch film 26 is provided on the rear surface 18B of the optical lens 18.

When necessary, the touch film 26 is inserted between the optical lens 18 and the light coupling layer 24; in this case, the light coupling layer 24 is not in direct contact with the rear surface 18B of the optical lens 18.

The manufacturing method of the electronic display system 10 is described with reference to FIG. 3 .

The manufacturing method comprises: step E1, obtaining an initial optical layer 20, 22; step E2, using a replica template to manufacture subsequent optical layers 20, 22. Each subsequent optical layer 20, 22 is manufactured on a pre-molded optical layer 20, 22 using a replica template. Preferably, the initial optical layer 20, 22 is molded.

In one embodiment, the initial optical layer is the front optical layer 20 of the optical lens 18, and each subsequent optical layer 22 is made behind the previous optical layer using a replica template.

When the optical lens comprises exactly two optical layers 20, 22, the manufacturing method comprises: molding the front optical layer 20, and then manufacturing the rear optical layer 22 on the front optical layer 20 using a replica template.

In another embodiment, the initial optical layer is the front optical layer 20 of the optical lens 18, and each subsequent optical layer 22 is made using a replica template on the front of the previous optical layer.

When the optical lens 18 includes exactly two optical layers 20, 22, the manufacturing method includes: molding the rear optical layer 22, and then using a replica template to manufacture the front optical layer 20 on the rear optical layer 22.

If the optical lens 18 comprises two adjacent optical layers 20, 22 that are interposed in overlapping molds, the second molded optical layer is fabricated on the first molded optical layer using a replica template after the touch film 26 is applied to the first molded optical layer.

The method thus comprises a step E1 'of applying a touch film on a preceding optical layer before making a subsequent optical layer using a replica template on the preceding optical layer, so that the touch film 26 is interposed between the preceding optical layer and the subsequent optical layer.

When the optical lens 18 accurately includes two optical layers 20 and 22, the manufacturing method includes, for example: molding the front optical layer 20, applying the touch film 26 on the back of the front optical layer 20, and then using a replica template to manufacture the rear optical layer 22 on the front optical layer 20; or, molding the rear optical layer 22, applying the touch film 26 on the front of the rear optical layer 22, and then using a replica template to manufacture the front optical layer 20 on the rear optical layer 22.

The manufacturing method includes: step E3, disposing the optical lens 18 in front of the display screen 16, wherein the rear surface 18B of the optical lens 18 is parallel to the display surface 16A of the display screen 16 and is spaced apart from the latter.

The manufacturing method optionally includes: step E4, manufacturing a light coupling layer 24 between the rear surface 18B of the optical lens 18 and the display surface 16A of the display screen 16. The light coupling layer 24 is molded between the rear surface 18B of the optical lens 18 and the display surface 16A of the display screen 16, for example.

The molding of the optical layers 20, 22 is achieved, for example, by injection molding (ie by melt pouring in a sealed injection mold) or compression molding (ie by melt insertion into an open mold and then closing the mold to achieve shaping of the material).

The optical lens 18 having a plurality of overlapping optical layers 20, 22 obtained by using a replica template to manufacture the optical layer enables the obtained optical lens to have a certain thickness while limiting optical defects such as mold marks caused by molding a thick single-piece optical lens 18.

Optical lenses 18 having overlapping optical layers 20, 22 can be molded more quickly than optical lenses of the same overall shape made in a single molding operation because the cooling time is dependent on the thickness of the molded part.

The optical lens 18 having a plurality of overlapping optical layers 20, 22 also facilitates obtaining an optical lens 18 having a front surface 18A and a rear surface 18B of different shapes, in particular a curved front surface 18A and a planar rear surface 18B.

The planar rear surface 18B is manufactured to facilitate optical coupling with the display screen 16 having a planar display surface 16A. This can, in particular, enable the optical coupling layer 24 to have a constant thickness and/or minimize the thickness of the optical coupling layer 24.

The optical lens 18 manufactured using a replicated template can have lower cost and higher quality, as well as better repeatability, limiting the scrap rate during the manufacturing process of the electronic display system 10 .

Furthermore, it has been observed that, in particular when photogels are used, locally excessive thickness of the light coupling layer 24 can promote breakage of the optical lens 18 when the optical lens is subjected to impact, for example during an analog test for impacts of a passenger's head on the optical lens 18, for example according to the ECE21 HEAD IMPACT 78/632/CEE standard.

The multiple optical layers 20, 22 manufactured can limit the above risks, especially when the rear surface 18B of the rear optical layer 22 is parallel to the display surface 16A of the display screen 16, so that the optical coupling layer 24 inserted between the rear optical layer 22 and the display surface 16A of the display screen 16 has a substantially uniform thickness on the rear surface 18B of the optical lens 18.

10: Electronic display system 12: Support 14: Encapsulation 16: Display screen 16A: Display surface 18: Optical lens 18A: Front surface 18B: Rear surface 20: Optical layer/front optical layer 20A: Front of front optical layer 20B: Rear of front optical layer 22: Optical layer/rear optical layer 22A: Front of rear optical layer 22B: Rear of rear optical layer 24: Optical coupling layer 26: Touch film E1, E1', E2, E3, E4: Steps

The invention and its advantages will be better understood by reading the following description, which is given by way of non-limiting example only and is illustrated with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional view of an electronic display system; Figure 2 is a cross-sectional view of an electronic display system; Figure 3 is a schematic diagram of a method for making an electronic display system.

10: Electronic display system

12: Support parts

14: Layering

16: Display screen

16A: Display surface

18:Optical lens

18A: front surface

18B: Back surface

20: Optical layer/front optical layer

20A: Front of the front optical layer

20B: Behind the front optical layer

22: Optical layer/post-optical layer

22A: The front of the rear optical layer

22B: Behind the rear optical layer

24: Optical coupling layer

Claims (14)

An electronic display system includes a display screen and an optical lens, wherein the display screen is configured to display an image on a planar display surface, the optical lens is arranged in front of the display surface so that the display surface is visible through the optical lens, the optical lens has a curved front surface on the opposite side of the display surface and a rear surface on the side of the display surface, wherein the optical lens is formed by a plurality of optical layers superimposed on each other, the plurality of optical layers include a front optical layer defining the front surface and a rear optical layer defining the rear surface, the optical layers are made using a replica template, wherein the rear surface of the optical lens is spaced apart from the display surface. An electronic display system as described in claim 1, wherein the front surface of the optical lens is convex and/or concave. An electronic display system as described in claim 1, wherein the front optical layer has a curved back surface. An electronic display system as described in claim 2, wherein the rear surface of the front optical layer is convex and/or concave. An electronic display system as described in claim 1, wherein the rear surface of the optical lens is planar and parallel to the display surface of the display screen. An electronic display system as described in claim 1, wherein the optical lens precisely includes two optical layers, the two optical layers being the front optical layer and the rear optical layer. An electronic display system as described in claim 1, wherein at least two optical layers are made of the same material. An electronic display system as described in claim 1, wherein at least two optical layers are made of different materials. The electronic display system as described in claim 1 includes an optical coupling layer inserted between the display surface of the display screen and the rear surface of the optical lens. The electronic display system as described in claim 1 includes a touch film inserted between two optical layers of overlapping molds. A method for manufacturing an electronic display system as described in claim 1, comprising: obtaining the optical lens by molding the optical layer, and arranging the optical lens in front of the display screen, wherein the rear surface of the optical lens is parallel to the display surface of the display screen. The manufacturing method as described in claim 11 includes: optically coupling the display screen and the optical lens by inserting an optical coupling layer between the rear surface of the optical lens and the display surface of the display screen. A manufacturing method as described in claim 12, wherein the optical coupling layer is molded between the display surface of the display screen and the rear surface of the optical lens. The manufacturing method as described in claim 11 includes: in the process of molding the optical lens, before using a replica template to make an additional optical layer on the pre-molded optical layer, applying a touch film on the pre-molded optical layer so that the touch film is inserted between the pre-molded optical layer and the additional optical layer.