Display panel and display device

Abstract

To stably fix a resin molding without appearance of swelling on a surface of a display panel, suppress small a compression force of a resin during molding and suppress occurrence of swelling on a glass surface by reducing a tensile elasticity modulus of the resin molding.SOLUTION: A resin molding such as a lock portion to be fixed to a housing is integrally provided at a rear face side of a thin glass display panel. A display panel 1 is formed by integrally fixing a resin molding 3 to be the lock portion to a rear face of a glass substrate 2. A thermoelastic elastomer is contained as a material to be used of the resin molding 3, and a resin having a tensile elastic modulus of 100 MPs or less is used.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention displays information and images such as car navigation. display device Regarding the display panel. [Background technology]

[0002] Display panels for in-vehicle display devices that display various information and images are made of synthetic resin or glass, but glass panels are often used in high-end devices because the glossy texture of the panel creates a sense of luxury. The display panel is attached to the front frame of the housing that houses the electronic device, and in many cases, the back side of the glass display panel is attached to the front frame using adhesive tape or the like.

[0003] The method of attaching and fixing a display panel to a housing using adhesive tape or the like is cumbersome, requiring the preparation of the adhesive tape needed for fixing and the adjustments required to accurately position the panel. Furthermore, if the display panel needs to be replaced due to scratches or damage, it is difficult to do so if it is fixed with adhesive tape or the like.

[0004] Therefore, instead of the above-mentioned fixing method by adhesion, a method is being considered in which a locking portion such as a rib made of a resin material is integrally attached to the back side of a glass display panel by outsert molding, and the locking portion is connected to a locking portion provided on the front frame portion of the housing to attach the display panel to the housing (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-159114 Summary of the Invention [Problem to be solved by the invention]

[0006] When a locking portion is provided on the back side of a glass display panel by outsert molding, if the locking portion is thick and wide, there is a problem that the difference in thermal contraction between the glass and the resin causes the locking portion to be insufficiently fixed to the back side of the display panel, making the locking portion prone to peeling off.

[0007] Furthermore, in order to improve the design of the glass display panel, it is required to form the display panel into a gently curved shape. For example, if the display panel of a car navigation system is formed into a glossy curved glass shape, it will have an attractive appearance, but in this case, if the display panel is fixed to the front surface of the housing with adhesive tape, there is a concern that the adhesive tape will gradually peel off during use, causing the display panel to fall off.

[0008] To eliminate the risk of the display panel dropping, it is desirable to physically secure the display panel to the housing, for example, by providing a locking portion on the back of the display panel and connecting it to a locking portion on the housing. However, if the locking portion is thick, as described above, the difference in thermal contraction between the glass and the resin can easily lead to insufficient adhesion of the locking portion. Furthermore, in cases where the locking portion is provided on the back of thin glass that can be processed into a curved shape by outsert molding, there is a problem in that the thermal contraction of the resin used for the locking portion can cause a slight convex bulge (sink mark) on the surface of the glass directly behind the locking portion. The undulations on the glass surface appear as streaky gloss when the display panel reflects external light, which can degrade the appearance of the beautifully curved display panel.

[0009] In view of the above problems of the conventional technology, the present invention has been made. Display panel In this case, when a resin molding is integrally provided on the back side of a thin glass display panel as a locking part for fixing to a housing, the object is to make it possible to stably fix the resin molding to the back side of the display panel without causing any undulations to appear on the surface of the display panel. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, the inventors investigated the conditions under which undulations appear on the surface of the glass when a resin molded body is provided on the back surface of the glass that constitutes a display panel. They found that undulations do not appear when the glass is sufficiently thick compared to the thickness of the resin molded body, but when glass with a thickness of about 0.3 mm is used and a resin molded body is provided on the back surface of this, undulations are likely to appear on the surface of the glass even if the thickness of the resin molded body is small.

[0011] Figure 3 shows the appearance of the front side of a display panel. The illustrated display panel 1 is formed by fixing a resin molding 3, which serves as a fastening portion, to the rear surface of a glass substrate 2, which has an adhesive layer 22 arranged along the periphery of the rear surface of a glass plate 21. The waviness of the glass surface often appears as a convex shape, higher in the center and slightly lower around it, on the surface of the glass plate 21 directly behind the portion where the resin molding 3 is fixed. As shown in Figure 4, when the glass is thin, the contraction force (amount of contraction) CF of the resin that comes into contact with the back surface of the glass and hardens into the shape of the molded body is greater than the force that holds the glass flat (static force of the glass) SF, and this contraction force CF acts to cause the part of the glass where the resin molded body is attached to be locally deformed into a convex shape (the part indicated by the dashed line in the figure), and it is presumed that this convex deformation is the cause of the waviness that appears on the surface of the glass.

[0012] According to this speculation, if the contraction force of the resin is smaller than the static force of the glass, or if the resin itself is weaker than the static force of the glass, it is expected that the occurrence of undulations can be suppressed. Based on the above findings and assumptions, the inventor selected the material to be used for the resin molding, and verified whether the resin molding could be fixed to glass with a contraction force smaller than the static force of the glass, thereby completing the present invention.

[0013] That is, the gist of the present invention is as follows. [1] A configuration in which a resin molding is provided on at least a portion of one of the front and rear surfaces of a glass substrate. Display panel And, The resin molding contains a thermoplastic elastomer, and the resin molding has a tensile modulus of elasticity of 100 MPa or less and a rubber hardness of 95 or less on the A scale in accordance with JIS-K-6253. Display panel . [2] The glass substrate according to [1], wherein the thickness of the glass substrate is 0.2 mm or more and 2.0 mm or less. Display panel . [3] The indication according to [2] above, in which the thickness of the glass substrate is 0.5 mm or less. panel . [4] The thermoplastic elastomer according to any one of [1] to [3], wherein the thermoplastic elastomer is a polyester-based thermoplastic elastomer. Display panel . [5] The resin molding is formed in a part of the glass substrate, and the flatness of a 15 mm square on the surface of the glass substrate opposite to the part where the resin molding is formed is 20 μm or less, according to any one of [1] to [4]. Display panel . [6] The display panel according to any one of [1] to [5], wherein a print layer and an adhesive layer are laminated on a glass substrate, and a resin molded body is disposed on the adhesive layer. Display panel . [7] The method according to any one of [1] to [6] above. Display panel A display device comprising: The above-mentioned "JIS-K-6253" standard was created based on ISO7619-1. [Effects of the Invention]

[0014] According to the in-vehicle display panel of the present invention, even if a resin molding such as a locking portion for fixing to a housing is integrally provided on the back side of a thin glass display panel, the resin molding can be stably fixed to the back side of the display panel without causing any undulations to appear on the surface of the display panel. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram showing the front and back surfaces of a display panel, which is a composite manufactured in an example, divided into parts. [Figure 2] 2 is an enlarged cutaway perspective view of a portion of the display panel of FIG. 1 where a resin molded body is provided. [Figure 3] FIG. 2 is an enlarged external view of the front side of the display panel of FIG. [Figure 4] FIG. 4 is an enlarged cross-sectional view taken along line IV-IV in FIG. [Figure 5] 1 is a graph showing measurement results of an example and a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0016] Preferred embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be modified and implemented as appropriate within the scope of the gist of the present invention.

[0017] As described above, the present invention provides an in-vehicle display panel having a configuration in which a resin molding is provided on at least a portion of one of the front and rear surfaces of a glass substrate, wherein the resin molding contains a thermoplastic elastomer, and the resin molding has a tensile modulus of elasticity of 100 MPa or less and a rubber hardness of 95 or less on the A scale in accordance with JIS-K-6253.

[0018] Elastomers are soft polymers with rubber-like elasticity, and resin materials containing them are fluid at high temperatures, making them easy to process, and they have the characteristic of being strong even without fillers. By forming the resin molded body, which is the aforementioned locking portion, from a material containing a thermoplastic elastomer, the resin molded body can be stably fixed to the glass surface. In addition, the shrinkage force of the resin during molding is small, and is lower than the static force of the glass, making it possible to suppress the occurrence of undulations on the glass surface. The tensile modulus of a resin molded body made of a material containing a thermoplastic elastomer is preferably 100 MPa or less. If the tensile modulus is greater than 100 MPa, the resin molded body will be hard, and the shrinkage force of the resin during molding will be large, exceeding the static force of the glass and making the glass surface more susceptible to undulations. If the tensile modulus is 100 MPa or less, the convex deformation of the glass will be kept small, making the undulations less noticeable, or the shrinkage force of the resin will be smaller than the static force of the glass, preventing undulations from occurring. If the tensile modulus is too small, the resin molded body will be too soft and will no longer function as a fastening member, making it difficult to physically secure the display panel to the housing of the display device. Therefore, the lower limit of the tensile modulus of the resin molded body is preferably 2 MPa or more, more preferably 9 MPa or more, and the upper limit is preferably 70 MPa or less, more preferably 50 MPa or less.

[0019] In the in-vehicle display panel having the above configuration, the thermoplastic elastomer preferably has a rubber hardness of 95 or less. The rubber hardness referred to here means the rubber hardness on the A scale in accordance with JIS-K-6253. If the rubber hardness of a resin molded article made of a material containing a thermoplastic elastomer is 95 or less, the resin molded article is appropriately soft, and the transmission of the contraction force of the resin to the glass at the joint interface between the glass and the resin can be suppressed, preventing undulation. If the rubber hardness is 40 or more, the resin molded article has an appropriate hardness for use as a locking member. The lower limit of the rubber hardness is preferably 50 or more, and more preferably 55 or more. The upper limit is preferably 85 or less, and more preferably 80 or less.

[0020] Furthermore, it is preferable that the resin molding is formed on a part of the glass substrate, and that the flatness of a 15 mm square on the surface of the glass substrate opposite the part where the resin molding is formed is 20 μm or less. If the flatness of the surface of the glass substrate satisfies the above numerical conditions, undulations will not be noticeable in appearance, and there will be no effect on the display output of information and images on the display panel.

[0021] The in-vehicle display panel of the present invention can be configured such that a print layer and an adhesive layer are laminated on a glass substrate, and a resin molded body is disposed on the adhesive layer. For example, when the in-vehicle display panel of the present invention is a display panel for car navigation, the glass substrate can be formed by forming a black printed layer in a strip shape along the four peripheral sides of a glass plate that is rectangular in plan view on the back side of the glass plate, laminating an adhesive layer on the surface of this printed layer, and forming a resin molded body on this adhesive layer.

[0022] The ink for forming the printing layer may be any ink that can be used for direct printing on a glass plate, and commercially available inks for printing on glass plates can be used. From the viewpoint of adhesion to glass, ink containing a silane coupling agent is preferred. The ink is used by adding a black colorant such as carbon black, and the printed layer forms a black colored portion on the surface of the glass plate.

[0023] The adhesive layer may be any adhesive that can bond the printed layer to the resin molded body to be outsert molded. Furthermore, commercially available binder inks and adhesion enhancers for use in injection molding can also be used.

[0024] The glass substrate having a printed layer and an adhesive layer laminated on one side of the glass plate preferably has a thickness of 0.2 mm or more and 2.0 mm or less, and more preferably 0.5 mm or less when used to curve glass and hold and fix it in a curved shape. A thickness of 2.0 mm or less is preferable because it allows the weight of the in-vehicle display panel to be reduced and the load on the locking portion to be reduced, and it also allows the sensitivity of the sensor bonded to the back surface of the display panel to be improved. A thickness of 0.5 mm or less is preferable because the glass substrate can be processed to have a curved shape and can be installed in a housing while maintaining the curved shape, whereas a thickness of 0.2 mm or more is preferable because the glass substrate is less likely to break even when curved.

[0025] Examples of the glass substrate include borosilicate glass, aluminosilicate glass, and aluminoborosilicate glass. Also included are low-alkali and non-alkali glasses of these glasses. Further examples include silica glass and soda-lime glass. Among these, borosilicate glass, aluminosilicate glass, aluminoborosilicate glass, and low-alkali glasses thereof are preferred, and non-alkali glasses thereof are more preferred. The glass substrate may be colorless or colored, but is preferably colorless and transparent in order to improve the visibility of the display.

[0026] The resin molded body is made of a resin containing a thermoplastic elastomer, and it is more preferable to use a thermoplastic elastomer. Examples of the thermoplastic elastomer used in the resin molded article include styrene-based elastomers, vinyl chloride-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, nitrile-based elastomers, polyamide-based elastomers, etc. From the viewpoint of adhesion to the adhesive layer, styrene-based elastomers, urethane-based elastomers, and polyester-based elastomers are preferred, and among these, polyester-based elastomers are more preferred. Although the resin molded product is preferably a thermoplastic elastomer alone, it may contain one or more known thermoplastic resins, such as ABS resin, polypropylene resin, polyamide resin, polycarbonate resin, POM resin, PMMA resin, PBT resin, and PC-ABS resin, as long as the tensile modulus is 100 MPa or less.

[0027] The in-vehicle display panel of the present invention can be used as a display panel for devices that display various information and images, such as car navigation systems, meter panels, and heater controllers.

[0028] The in-vehicle display panel of the present invention will be described below based on examples. However, the examples shown below are merely examples for embodying the technical concept of the present invention, and the present invention is not limited to the embodiments described below.

[0029] An in-vehicle display panel according to the present invention shown in FIG. 1 was produced. This display panel 1 is designed to be used as a display panel for car navigation, and is constructed by arranging a resin molding 3, which serves as a fastening portion, integrally on the back side of a rectangular glass substrate 2.

[0030] As shown in Figures 1 and 2, the glass substrate 2 has a black colored portion 22 in the form of a strip along the four peripheral sides of the back surface of a transparent glass plate 21, and is formed to a thickness of about 0.5 mm overall.

[0031] The colored portion 22 is formed by laminating an adhesive layer 22b on a printed layer 22a provided on the back surface of the glass substrate 2. More specifically, the printed layer 22a is formed by applying an ink made of an acrylic urethane resin containing a silane coupling agent in a frame shape along the periphery of the back surface of the glass plate 21, and after the printed layer 22a has dried, a two-component curing polyurethane ink is applied to its surface and dried, thereby laminating the adhesive layer 22b on the top surface of the printed layer 22a.

[0032] The resin molding 3 is fixed to the rear surface of the glass substrate 2 at three locations: the center of the upper edge and the lower parts of the left and right edges. The material used for the resin molding 3 was changed, and performance evaluations were carried out, including whether or not undulations appeared on the surface of the display panel 1. [Example]

[0033] Example 1 The thermoplastic polyester elastomer "Hytrel (registered trademark) 4047N" (Toray-DuPont Co., Ltd.) was used as the material for the resin molding, and the resin molding was integrally fixed to the back surface of the glass substrate by injection molding to produce a display panel.

[0034] Using this material, a plate sample measuring 100 mm x 100 mm and 2 mm thick was produced by injection molding. The rubber hardness of the prepared samples was measured using a fully automatic micro rubber hardness tester, Model MD-1 Type A, JIS A approximation value (Kobunshi Keiki Co., Ltd.), owned by the Shiga Prefecture Northeast Industrial Technology Center. The measured rubber hardness was 92 in the first measurement and 93 in the second measurement. Furthermore, the rubber hardness of the prepared sample was measured in accordance with JIS-K-6253 using a durometer type A. The measured rubber hardness was 94.

[0035] The elastic modulus of the materials used was determined by a tensile test in accordance with JIS K 6251: 2010. Dumbbell-shaped No. 2 test pieces were used. For the manufactured display panel, as shown in Figure 3, the flatness of a 15mm square glass substrate centered on the center of the resin molded body 3 on the front side of the glass substrate of the display panel 1 was measured directly behind the resin molded body 3 located in the center of the upper edge of the back side of the display panel 1. The flatness was measured using a "Surface Roughness and Contour Measuring Instrument Formtracer Avant FTA-D4000" (Mitutoyo Corporation). Measurements using this measuring instrument conform to the surface quality evaluation standards JIS B 0633:2001 and JIS B 0651:2001. Furthermore, it was visually confirmed whether or not undulations appeared on the surface of the manufactured display panel. The above measurement results and confirmation results are shown in Table 1.

[0036] Example 2 A thermoplastic polyester elastomer "Hytrel (registered trademark) 3001" (Toray-DuPont Co., Ltd.) was used as the material for the resin molded body, and a display panel was produced in the same manner as in Example 1, and the same measurements and confirmations were carried out. The sample prepared in the same manner as in Example 1 was measured with the fully automatic micro rubber hardness tester, and the rubber hardness was 83 the first time and 84 the second time. The rubber hardness was also measured with the durometer and was 86.

[0037] Example 3 A display panel was produced in the same manner as in Example 1 using a thermoplastic polyester elastomer "TEFABLOC (registered trademark) A1700N" (Mitsubishi Chemical Corporation) as the material for the resin molded body, and the same measurements and confirmations were carried out. The sample prepared in the same manner as in Example 1 was measured with the fully automatic micro rubber hardness tester, and the rubber hardness was 60 the first time and 76 the second time. The rubber hardness was also measured with the durometer and was 78.

[0038] Example 4 A display panel was produced in the same manner as in Example 1 using a thermoplastic polyester elastomer "TEFABLOC (registered trademark) A1600N" (Mitsubishi Chemical Corporation) as the material for the resin molded body, and the same measurements and confirmations were carried out. The sample prepared in the same manner as in Example 1 was measured with the fully automatic micro rubber hardness tester, and the rubber hardness was 53 the first time and 66 the second time. The rubber hardness was also measured with the durometer and was 69.

[0039] Example 5 A display panel was produced in the same manner as in Example 1 using a thermoplastic polyester elastomer "TEFABLOC (registered trademark) A1400N" (Mitsubishi Chemical Corporation) as the material for the resin molded body, and the same measurements and confirmations were carried out. The sample prepared in the same manner as in Example 1 was measured with the fully automatic micro rubber hardness tester, and the rubber hardness was 43 the first time and 43 the second time. The rubber hardness was also measured with the durometer and was 47.

[0040] Comparative Example 1 A thermoplastic polyester elastomer, "Hytrel (registered trademark) 7247" (Toray-DuPont Co., Ltd.), was used as the material for the resin molded body, and an attempt was made to fabricate a display panel similar to that in Example 1. However, the resin molded body peeled off from the glass substrate and could not be fixed. The resin molded body was measured with a fully automatic micro rubber hardness tester, and the rubber hardness was 99 the first time and 99 the second time. The rubber hardness was also measured with a durometer and was 99.

[0041] Comparative Example 2 A thermoplastic polyester elastomer "Hytrel (registered trademark) 5557" (Toray-DuPont Co., Ltd.) was used as the material for the resin molded body, and a display panel was produced in the same manner as in Example 1, and the same measurements and confirmations were carried out. The sample prepared in the same manner as in Example 1 was measured with the fully automatic micro rubber hardness tester, and the rubber hardness was 97 the first time and 98 the second time. The rubber hardness was also measured with the durometer, and was 98.

[0042] [Table 1]

[0043] In the "Waviness Evaluation" in Table 1, when visually inspected, if the waviness was not noticeable at all, it was marked with "Good", if it was slightly noticeable, it was marked with "Good", and if it was noticeable, it was marked with "Poor".

[0044] 5 is a graph showing the relationship between the modulus of elasticity for each material and the measured flatness of the glass of the display panel in each Example and Comparative Example 2. In the figure, "Ex. 1" to "Ex. 5" refer to "Example 1" to "Example 5," and "Comp. 2" refers to "Comparative Example 2."

[0045] As shown in Table 1, when the presence and condition of undulations on the surface of the display panel were visually confirmed, undulations were clearly observed in Comparative Example 2, and although undulations were observed with a closer look in Example 1, they were small and only slightly noticeable. Furthermore, in Examples 2 to 5, undulations were not noticeable at all, and no undulations were visually confirmed. From the observation of the display panels of each example and comparative example, it was found that the appearance of the slightly noticeable undulations in Example 1 would not be impaired even when used in a car navigation display panel, and would not pose any practical problems.

[0046] According to the results of visually inspecting the above-mentioned waviness, it is estimated that if the rubber hardness of the material used for the resin molding is 95 or less, which is lower than that of the material in Comparative Example 2 and slightly higher than that of the material in Example 1, it will be possible to make the waviness that occurs on the display panel less noticeable to the point where it is not noticeable. Furthermore, as shown in the graph of FIG. 5, if the modulus of elasticity of the material used is 100 MPa or less, preferably 68 MPa or less, which is the modulus of elasticity of the material of Example 1, it is estimated that it is possible to make the undulations that occur on the display panel less noticeable or to prevent the undulations from occurring. Furthermore, if the flatness of the display panel is 20 μm or less, preferably 15 μm or less, which is the flatness measured in Example 1, it is estimated that it is possible to make the waviness that occurs on the display panel less noticeable or to prevent the waviness from occurring.

[0047] In the above embodiment, the composite of the present invention is applied to the display panel of a car navigation system, but it can also be applied to the display panel of other information display devices. In this case, the display panel is formed to a size corresponding to the display device, and an appropriate number of resin molded bodies are provided on the back surface of the glass substrate at appropriate positions on the back surface of the glass substrate according to the size of the display device. The shapes and combinations of the glass substrate and resin molded body that constitute the composite of the present invention are merely examples, and various modifications can be made based on design requirements and the like within the scope of the present invention. [Explanation of symbols]

[0048] 1 in-vehicle display panel, 2 glass substrate, 21 glass plate, 22 colored portion, 22a printed layer, 22b adhesive layer, 3 resin molded body

Claims

1. A display panel having a configuration in which a resin molding that serves as a locking portion, such as a rib, that is connected to a locking portion of a housing is provided on one of both front and rear side surfaces of a glass substrate, the resin molded body contains a thermoplastic elastomer, the resin molded body has a tensile modulus of 2 MPa or more and 100 MPa or less, and a rubber hardness of 95 or less on the A scale in accordance with JIS-K-6253; A display panel characterized in that the thickness of the glass substrate is 0.2 mm or more and 2.0 mm or less.

2. 2. The display panel according to claim 1, wherein the thickness of the glass substrate is 0.5 mm or less.

3. 3. The display panel according to claim 1, wherein the thermoplastic elastomer is a polyester-based thermoplastic elastomer.

4. 3. A display panel according to claim 1, wherein the resin molding is formed in a part of the glass substrate, and the flatness of a 15 mm square area on the opposite side of the glass substrate opposite the part of the glass substrate where the resin molding is formed is 20 μm or less.

5. 3. The display panel according to claim 1, wherein a print layer and an adhesive layer are laminated on a glass substrate, and the resin molded body is disposed on the adhesive layer.

6. A display device comprising the display panel according to claim 1 or 2.

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