阅读说明：本技术 用于将保护屏层压到柔性显示器支承件上的方法以及用于实施所述层压方法的模具 (Method for laminating a protective screen to a flexible display support and mould for carrying out said lamination method ) 是由 路易斯·阿森西奥 马塞尔·万尼 于 2020-01-31 设计创作，主要内容包括：本发明涉及一种用于将保护屏(3)层压到柔性显示器支承件(4),特别是电子瓦片上的方法,所述方法基于借助于可弹性变形的冲头(18)使保护屏(3)和显示器支承件(4)渐进地接触,直到在以下列构造中获得所述保护屏(3)与所述显示器支承件(4)之间接触的最大面积(4a)：在该构造中,由保护屏(3)与显示器支承件(4)形成的组件是完全层压的,因此冲头(18)的外表面具有与显示器支承件(4)的三维形状大体上相同的三维形状。(The invention relates to a method for laminating a protective screen (3) onto a flexible display support (4), in particular an electronic tile, based on progressively contacting the protective screen (3) and the display support (4) by means of an elastically deformable punch (18) until a maximum area of contact (4a) between the protective screen (3) and the display support (4) is obtained in the following configuration: in this configuration, the assembly formed by the protective screen (3) and the display support (4) is fully laminated, so that the outer surface of the punch (18) has a three-dimensional shape substantially identical to that of the display support (4).)

1. A method for laminating a protective screen (3) onto a flexible display support (4), in particular a method for laminating a protective screen (3) onto an electronic panel, the method comprising the steps of:

a) providing a transparent or translucent protective screen (3) having a curved three-dimensional shape;

b) providing a flexible display support (4), the flexible display support (4) having a curved three-dimensional shape substantially the same as the three-dimensional shape of the protective screen (3), and preferably the flexible display support (4) is at least partially covered by an adhesive film;

c) -positioning and fixing said protection screen (3) on the lower part (11) of the mould (10);

d) positioning and fixing the display support (4) on an upper portion (12) of the die (10) equipped with an elastically deformable punch (18), the display support (4) being positioned so that the display support (4) rests on a curved outer surface of the punch (18), the three-dimensional shape of said outer surface then being slightly different from the three-dimensional shape of the display support (4);

e) optionally, depositing glue on the display support (4) in case the display support (4) is not already covered with a glue film;

f) assembling the upper part (12) of the mould (10) on the lower part (11) of the mould (10) to form a mould (10), in which mould (10) the protective screen (3) and the display support (4) are initially out of contact with each other and such that the upper part (12) of the mould (10) is accessible to the lower part (11) of the mould (10) under the effect of a downward pressure applied to the upper part (12) of the mould (10);

g) bringing the lower and upper parts (11, 12) of the mould (10) together until at least one point contact is created between the protective screen (3) and the display support (4);

h) -bringing the lower and upper portions (11, 12) of the mould (10) progressively closer together so that the contact surface (4a) between the protective screen (3) and the display support (4) progressively increases until a maximum value corresponding to a fully laminated configuration of the assembly formed by the protective screen (3) and the display support (4) is reached, the outer surface of the punch (18) then having a three-dimensional shape substantially identical to the three-dimensional shape of the display support (4).

2. Method according to claim 1, characterized in that the punch (18) is at least partially and preferably entirely formed of an elastic material.

3. Method according to claim 1 or 2, characterized in that the punch (18) is formed of two parts, an outer part (18a) and an inner part (18b), the display support (4) resting on the outer part (18a), the inner part (18b) abutting the outer part (18a), the coefficient of compression of the outer part (18a) being smaller than the coefficient of compression of the inner part (18 b).

4. Method according to claim 1 or 2, characterized in that the punch (18) rests on a spring (21), the spring (21) being arranged inside the upper part (12) of the die (10) so that the punch can be displaced upwards in steps g) and h).

5. Method according to claim 1 or 2, characterized in that the punch (18) rests on an inflatable structure provided inside the upper portion (12) of the die (10), so that the position of the punch (18) can be varied according to the amount of air contained in the inflatable structure.

6. Method according to any one of the preceding claims, characterized in that the protective screen (3) is formed by injection of a plastic material.

7. The method according to claim 6, wherein the plastic material is selected from the group consisting of polyamide, polymethyl (meth) acrylate and polycarbonate.

8. A method according to any one of claims 1 to 5, characterized in that the protective screen (3) is formed of glass.

9. The method according to any one of the preceding claims, characterized in that the approach of the lower and upper parts (11, 12) of the mould (10) in steps g) and h) takes place by means of a press (22), the mould (10) formed by the assembly of the lower and upper parts (11, 12) being placed inside the press (22).

10. Method according to any one of the preceding claims, characterized in that it comprises an intermediate step g ') carried out before step g), said intermediate step g') comprising bringing the punch (18) to temperature to activate the glue covering the display support (4).

11. A mould (10) for implementing the lamination process according to any one of the preceding claims, said mould (10) comprising:

-a lower portion (11) intended to receive the protective screen (3),

-an upper part (12) equipped with an elastically deformable punch (18), the lower and upper parts (11, 12) being assembled together so that the lower and upper parts (11, 12) can be displaced relative to each other along a displacement direction,

-guiding means (15, 16) able to ensure the translational guiding of the upper part (12) and/or the lower part (11) along the displacement direction,

-damping means (17) arranged between said lower part (11) and said upper part (12), said damping means (17) being intended to keep said lower part at a distance from said upper part (11, 12).

12. Mould (10) according to claim 11, characterized in that said lower portion (11) is shaped so as to define a housing having a three-dimensional shape complementary to the three-dimensional shape of said protective screen (3).

13. Mould (10) according to claim 11 or 12, characterized in that said punch (18) is provided with fixing means suitable for positioning and retaining a flexible display support (4), in particular an electronic panel, on said upper portion (12).

14. Mould (10) according to claim 13, characterized in that said fixing means are mechanical, in particular comprising one or more clamps.

15. Mould (10) according to claim 13, characterized in that said fixing means are pneumatic, in particular able to create a vacuum below said display support (4).

16. Mould (10) according to any one of claims 11 to 15, characterized in that said guide means (15, 16) comprise a plurality of posts (15) fixed to said lower portion (11) and said upper portion (12) is slidable along said posts (15).

17. Mould (10) according to any one of claims 11 to 16, characterized in that said damping means are constituted by compression springs (17).

18. A decorative panel (1) for the passenger compartment of a motor vehicle, the decorative panel (1) being equipped with a three-dimensional display panel (2) obtained by the method according to any one of claims 1 to 10.

Technical Field

The present invention relates to a method for laminating a protective screen to a flexible display support, in particular an electronic panel. The invention also relates to a mould intended to implement such a lamination process, and to a decorative panel for the passenger compartment of a motor vehicle equipped with a three-dimensional display panel obtained by said process.

Background

In the automotive field, light-emitting display panels intended to be integrated into the passenger compartment of a vehicle are increasingly used. These display panels may in particular comprise electronic panels integrated into the cabin of the vehicle and allow the transmission of luminous information to the driver or passenger to get their attention by means of displays of the LED, LCD or OLCD type, for example. Such an electronic panel may have an interface for electronic communication, for example with an on-board computer of the vehicle, so as to be able to display information relating to the vehicle itself, for example the speed of the vehicle, or information relating to the external environment, for example the external temperature. Such electronic panels are typically covered by a transparent or translucent protective screen to prevent premature degradation of the panel due to impacts or contacts that may occur during use of the vehicle. Such protective screens are typically made of glass or plastic.

Currently, display panels of this type are generally planar or two-dimensional and are formed by laminating a protective screen to the panel by vacuum or roll coating application methods. However, these application methods have proven to be unsuitable when the display panel is not planar or two-dimensional. Indeed, during the lamination process, it is often found that air bubbles are trapped between the screen and the panel due to the curvature and undulation of the screen and panel. These bubbles may cause light scattering that alters the light path, resulting in a degraded display in the area where the bubbles are generated. The display panel is not entirely satisfactory.

Disclosure of Invention

One of the objects of the present invention is to overcome this drawback by proposing a lamination method that avoids air bubbles being trapped between the protective screen and the electronic panel.

To this end, the invention relates to a method for laminating a protective screen on a flexible display support, in particular an electronic panel, comprising the steps of:

a) providing a transparent or translucent protective screen having a curved three-dimensional shape;

b) providing a flexible display support having a curved three-dimensional shape substantially identical to the three-dimensional shape of the protective screen, and preferably, the flexible display support is at least partially covered by an adhesive film;

c) positioning and securing the protective shield on the lower portion of the mold;

d) positioning and fixing a display support on an upper portion of a die equipped with an elastically deformable punch, said display support being positioned so that it rests on a curved outer surface of said punch, the three-dimensional shape of said outer surface then being slightly different from the three-dimensional shape of the display support;

e) optionally, depositing glue on the display support in the case that the display support has not been covered with a glue film;

f) assembling an upper portion of a mold on a lower portion of the mold to form the mold in which the protective screen and the display support are initially out of contact with each other and such that the upper portion of the mold is accessible to the lower portion of the mold under a downward pressure applied to the upper portion of the mold;

g) bringing the lower and upper portions of the mold together until at least one point contact is made between the protective screen and the display support;

h) the lower and upper portions of the mold are brought progressively closer together so that the contact surface between the protective screen and the display support progressively increases until a maximum value corresponding to the fully laminated configuration of the assembly formed by the protective screen and the display support is reached, and then the outer surface of the punch has a three-dimensional shape substantially identical to the three-dimensional shape of the display support.

The method of the invention may further comprise one or more of the following features:

the punch is at least partially, and preferably entirely, formed of an elastic material.

The punch is formed by two parts, an outer part on which the display stand rests and an inner part adjoining the outer part, the compressibility of the outer part being smaller than the compressibility of the inner part.

The punch rests on a spring which is arranged inside the upper part of the die so that it can be displaced upwards in steps g) and h).

The punch rests on an inflatable structure, which is arranged inside the upper part of the mould, so that the position of the punch can be varied according to the amount of air contained in the inflatable structure.

The protective screen is formed by injection of a plastic material.

The plastic material is preferably selected from polyamides, polymethyl methacrylate and polycarbonate.

The protective screen is made of glass.

-bringing together the lower part and the upper part of the mould in steps g) and h) takes place through a press, inside which a mould formed by the assembly of the lower part and the upper part is placed.

-the method comprises an intermediate step g') carried out before step g), comprising bringing the punch to temperature to activate the glue covering the display support.

The invention also relates to a mould for implementing a lamination process as described above, comprising:

intended to receive the lower part of the protective screen,

an upper part equipped with an elastically deformable punch, the lower part and the upper part being assembled together such that the lower part and the upper part can be moved relative to each other along a displacement direction,

-guiding means adapted to ensure translational guiding of the upper and/or lower part along said displacement direction,

-damping means arranged between the lower part and the upper part, said damping means being intended to keep said lower part at a distance from the upper part.

The mold of the invention may also comprise one or more of the following features:

the lower part is shaped so as to define a housing having a three-dimensional shape complementary to the three-dimensional shape of the protective screen.

The punch is provided with fixing means adapted to ensure positioning and holding of the flexible display support, in particular the electronic panel, on the upper portion.

The fixing means are mechanical, in particular comprising one or more clamps.

The fixing means are pneumatic, in particular capable of creating a vacuum below the display support.

The guide means comprise a plurality of posts fixed to the lower part, and the upper part can slide along said posts.

The damping means are constituted by a compression spring.

The invention also relates to a decorative panel for the passenger compartment of a motor vehicle, equipped with a three-dimensional display panel obtained by the lamination process as described above.

Drawings

Other aspects and advantages of the invention will become apparent from a reading of the following description, given by way of example and with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a decorative panel of a passenger compartment of a motor vehicle equipped with a three-dimensional display panel obtained by the method of the invention;

FIG. 2 is a perspective view of a protective screen that can be used to implement the method of the present invention;

FIG. 3 is a perspective view of a flexible display support for use in practicing the method of the present invention;

FIG. 4 is a perspective view of a lower portion of a mold that can be used to practice the method of the present invention;

FIG. 5 is a perspective view of an upper portion of a mold that can be used to practice the method of the present invention;

figure 6 is a perspective view of the respective positions of the lower part and the upper part shown in figure 4 when the lower part and the upper part are assembled;

FIG. 7 is a perspective view of the die shown in FIG. 6 just prior to entering the press;

FIG. 8a shows the relative positions between the shield, display support and punch at the beginning of the approach between the upper part of the die and the lower part of the die;

FIG. 8b shows the relative positions between the shield, display support and punch at an intermediate stage of approach between the upper portion of the die and the lower portion of the die;

FIG. 8c shows the relative positions between the shield, display support and punch near the end of the travel between the upper portion of the die and the lower portion of the die;

FIG. 9a is a perspective view of a first punch configuration that may be used in practicing the method of the present invention;

FIG. 9b is a perspective view of a second punch configuration that can be used to practice the method of the present invention;

FIG. 9c is a perspective view of a third punch configuration that can be used to practice the method of the present invention;

FIG. 10a is a bottom view of the display support showing the progression of the central contact region;

FIG. 10b is a view similar to FIG. 10a with the contact region advancing from one of the side edges;

FIG. 11 is a schematic representation of the steps of the method of the present invention.

Detailed Description

In the description, the term "exterior" means visible from or directed towards the inside of the passenger compartment of the motor vehicle, while the term "interior" means invisible from or directed towards the outside of the passenger compartment. Furthermore, the term "longitudinal" is defined in terms of the largest dimension of the trim panel, and the term "transverse" is defined in a direction perpendicular to the longitudinal direction.

With reference to fig. 1, a decorative panel 1 of a motor vehicle is shown, which decorative panel 1 comprises a display panel 2 intended to convey luminous information to a driver or passenger of the vehicle. The display panel 2 is located on a curved edge of the trim panel 1. The display panel 2 thus has a non-planar three-dimensional contour. As represented in fig. 2 and 3, the display panel 2 is formed on the one hand by a flexible display support 4 of the electronic panel type and on the other hand by a transparent protective screen 3 laminated on the outer surface of the display support 4. The protective screen 3 may have substantially the same dimensions as the display support 4, as in the example shown, or larger dimensions. In particular, as represented in fig. 8a to 8c, the protective screen 3 may also cover the entire outer surface of the trim panel 1. The protective screen 3 will be formed in particular of glass or of injection-moulded plastic, in particular of Polyamide (PA), polymethyl methacrylate (PMMA) or Polycarbonate (PC) or other translucent plastic material. As shown in fig. 5, the electronic panel-type display support 4 is equipped with a connection interface 5, this connection interface 5 being intended, for example, to be connected to a vehicle-mounted computer of the motor vehicle in order to receive electronic signals from said computer or from a camera device located outside the vehicle. In response to the electronic signal received, the display support 4 will thus transmit specific luminous messages, which will be visible from the passenger compartment of the vehicle. In an advantageous configuration, the display support 4 may advantageously be covered with an adhesive layer on the outer surface of the display support 4 in order to allow the protective screen 3 to be attached. The adhesive layer may in particular comprise a transparent optical adhesive film of OCA type, integrated into the display support 4 and protected by a protective sheet intended to be removed during lamination. In the absence of such an adhesive film, an additional step in the lamination process would be provided, including the deposition of a transparent optical adhesive layer on the outer surface of the display support 4 prior to contacting the protective screen 3 and the display support 4.

Referring to fig. 4, the lower part 11 of the mould is shown with the protective screen 3 fixed to the lower part 11 of the mould. The lower part 11 of the mould comprises in particular a supporting plate 13 of substantially rectangular shape, on the one hand two pairs of posts 15 projecting on the upper surface of the supporting plate 13, the posts 15 being arranged respectively near each top of the supporting plate 13, and on the other hand a receiving platform 19 projecting on the upper surface of the supporting plate 13 intended to receive the protective screen 3. The receiving platform 19 has in particular a shape complementary to the shape of the protective screen 3. The protective screen 3 is to be fixed either mechanically, for example by means of one or more clamps, or pneumatically, in particular by creating a vacuum below the protective screen 3, on said receiving platform 19. The support plate 13 is also provided with a pair of receiving holes inside which are housed compression spring type damping means 17, said springs protruding from the upper surface of the support plate 13. The function of the damping means 17 will be explained in more detail in the following paragraphs.

Referring to fig. 5, the upper part 12 of the mould is shown with the display support 4 secured to the upper part 12 of the mould. The upper part 12 of the die comprises in particular a supporting plate 14 of substantially rectangular shape, on the upper surface of which supporting plate 14 a punch 18 projects, on which punch 18 the display support 4 rests. The punch 18 is advantageously formed of an elastically deformable material so that the outer shape of the punch 18 can be changed in accordance with the pressure applied to the outer surface. When the punch 18 is not subjected to any pressure, the shape of the punch 18 will be slightly different from the shape of the display support, so that there may be a gap e between the punch 18 and the display support 4 on certain areas of the punch 18 (see e.g. fig. 9 a). In the configuration of fig. 5 and 9a, the punch 18 is formed from a single resilient material, such as rubber or silicone, which has a high compression coefficient. In another configuration, as represented in fig. 9b, the punch may be formed of two parts, an outer part 18a and an inner part 18b, the display support 4 resting on the outer part 18a, the inner part 18b abutting the outer part 18a, the outer part 18a having a lower compressibility than the inner part 18 b. In another possible configuration, as represented in fig. 9c, the punch 18 may rest on a spring 21, the spring 21 being arranged inside the support plate 14 of the upper part 12 of the mould, so that the punch 18 may move upwards during the contact of the protection screen 3 with the display support 4. These springs may be made of metal or of plastic. In another possible configuration, not shown, these springs 21 would be replaced by inflatable structures placed inside the support plate 14.

The display support 4 is to be fixed on the punch 18 either mechanically, for example by means of one or more clamps, or pneumatically, in particular by generating a vacuum below the display support 4. Furthermore, the support plate 14 is provided with two pairs of through holes 16, the through holes 16 being arranged close to each top of the support plate 14, respectively. These through holes 16 are intended to receive the posts 15 of the lower part 11 of the mould during assembly of the lower part 11 and the upper part 12 of the mould.

Referring to fig. 6, the respective positions of the lower part 11 and the upper part 12 of the mold are shown when the lower part 11 and the upper part 12 of the mold are assembled. The upper part 12 of the die is thus rotated by 180 ° on itself so that the punch 18 points downwards towards the receiving platform 19. The through-holes 16 are aligned with the posts 15. Subsequently, the support plate 12 is lowered in the direction of the support plate 11 until the support plate 12 comes into contact with the damping device 17. These damping means 17 can thus maintain a certain distance between the punch 18 and the receiving platform 19. The lower part 11 and the upper part 12 of the mould thus assembled form the mould 10.

Referring to fig. 7, a diagram of the mold 10 just prior to being placed under the press 22 is shown. The press 22 comprises in particular a lower plate 24 and an upper plate 26, between which the die 10 is positioned, said lower plate 24 and said upper plate 26 being movable close to each other by displacement means (not shown). When moved closer, the plates 24 and 26 exert a vertical pressure on the lower part 11 and the upper part 12 of the mould 10, which pressure tends to bring the lower part 11 and the upper part 12 of the mould 10 closer to each other. As shown in fig. 8a to 8c, this approach is advantageously performed gradually.

Referring to fig. 8a, the relative positions between the protective screen 3, the display support 4 and the punch 18 at the beginning of the approach between the upper part 12 of the die 10 and the lower part 11 of the die 10 are shown. It should be noted that in the shown construction the protective screen 3 is an integral part of the trim panel 1. During this initial phase, the display support 4 has not yet come into contact with the protective screen 3. As shown in an enlarged manner in fig. 9a, the punch 18 is still in its initial undeformed state. The protective screen 3 does not match exactly the outer surface of the punch 18, so that a vertical gap e is created between one of the side edges of the display support 4 and the outer surface of the punch 18, the distance between the display support 4 and said outer surface then decreasing gradually in the longitudinal direction.

Referring to fig. 8b, the relative positions between the protective screen 3, the display support 4 and the punch 18 are shown in the intermediate stage of approach between the upper part 12 of the die 10 and the lower part 11 of the die 10. In this intermediate stage, the display support 4 has been in contact with the protective screen 3 at the level of a contact area 4a, which contact area 4a extends over a small central part of the length L of the display support 4 and over the entire width L of the display support 4, as represented in fig. 10 a. According to a possible variant, as represented in fig. 10b, this contact area 4a can also be positioned on one of the side edges of the display support 4. According to another possible variant, not represented, the contact zone 4a may be substantially limited to one point. At this contact area 4a, the outer surface of the punch 18 has been deformed to allow the protective screen 3 to adhere uniformly and homogeneously to the display support 4 and thereby prevent the formation of intermediate air bubbles. Subsequently, the approach of the parts 11 and 12 of the mould 10 continues in a progressive manner, the contact zone 4a having been extended in the longitudinal direction of the display support 4 or in the direction of both side edges of the display support 4, as in the variant shown in fig. 10a, or in the direction of the opposite side edge, as in the variant shown in fig. 10 b. During this progressive approach, the outer surface of the punch 18 is progressively deformed to progressively conform to the outer contour of the display support 4. This progressive deformation can thus avoid the formation of intermediate air bubbles during the lamination of the protective screen 3 on the display support 4.

Referring to fig. 8c, the relative positions between the protective screen 3, the display support 4 and the punch 18 near the end of the travel between the upper part 12 of the mould 10 and the lower part 11 of the mould 10 are shown. In this final stage, the display support 4 is in full contact with the protective screen 3, and the contact area 4a covers the entire surface of the display support 4. The outer surface of the punch 18 then has a three-dimensional shape that is substantially the same as the three-dimensional shape of the display support 4.

Referring to fig. 11, a block diagram of the various steps of a lamination method 100 according to the present invention is shown.

In a first step 101, a transparent or translucent protective screen is provided and is formed either from a plastic material or from a glass material.

In a second step 102, a flexible display support having a curved three-dimensional shape substantially the same as the three-dimensional shape of the protective screen is provided, and preferably the flexible display support is at least partially covered by an adhesive film.

In a third step 103, the protective screen is positioned and fixed on the lower part of the mould.

In a fourth step 104, a display support is positioned and fixed on an upper part of a mould, which is equipped with an elastically deformable punch, said display support being positioned such that it rests on a curved outer surface of said punch, the three-dimensional shape of said outer surface then being slightly different from the three-dimensional shape of the display support.

In a fifth step 105, the adhesive film is deposited on the display support in case the display support has not been covered with the adhesive film.

In a sixth step 106, the upper part of the mould is assembled onto the lower part of the mould to form a mould in which the protective screen and the display support are initially out of contact with each other and such that the upper part of the mould can move close to the lower part of the mould under the action of a downward pressure applied to the upper part of the mould.

In a seventh step 107, the lower and upper parts of the mould are brought together until at least one point contact is made between the protective screen and the display support.

In an eighth step 108, the lower and upper portions of the mold are gradually approached so that the contact surface between the protective screen and the display support is gradually increased until a maximum value corresponding to the fully laminated configuration of the assembly formed by the protective screen and the display support is reached, then the outer surface of the punch has a three-dimensional shape substantially identical to the three-dimensional shape of the display support.

In addition to the above steps, other additional steps may be provided. In particular, it may be prepared to carry out an intermediate step comprising bringing the punch to temperature to activate the glue covering the display support before step 107.