Method for manufacturing an automotive display device, automotive display panel, and automotive display device.

Abstract

To provide a display panel for a vehicle with which it is possible to reduce leakage of light without compromising the strength and aesthetic appearance of the display panel for the vehicle and without generating abnormal noise in the display panel for the vehicle, and a display device for a vehicle that comprises the display panel for the vehicle.SOLUTION: In a groove formation step, a groove 23 is formed between display areas AR11, AR12 for performing display with light transmitted from a back side BS to a front side FS of a transparent resin molded body 21 and an end part 21E of the transparent resin molded body 21, and / or between the mutually adjacent display areas AR11, AR12, by cutting processing using computer numerical control along a prescribed shape so as to leave a thickness TH1 in a prescribed range. In a filling body formation step, the groove is filled with a colored resin that blocks light traveling in the transparent resin molded body 21, and a colored resin filling body 22 is formed in the groove.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a display device for a vehicle, a display panel for a vehicle, and a display device for a vehicle.

Background Art

[0002] A display device is provided on an instrument panel of a vehicle. The display device on the instrument panel includes, for example, a display of a navigation system and icons on a heater control panel as described in Patent Document 1 (Japanese Patent No. 7125713).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a display device for a vehicle, light propagates through a transparent resin molded body of a display panel for a vehicle and a heater control panel, and for example, light may leak from an end portion of the transparent resin molded body. Inside the vehicle at night, if light leaks from an end portion of the display panel for a vehicle or the heater control panel, the leaked light is very conspicuous. In order to reduce the light leakage from the end portion that occurs in such a transparent resin molded body, it is conceivable to provide means for blocking light at the location where light leaks. However, if the shape of the transparent resin molded body is made complicated in order to provide means for blocking light, the surface of the transparent resin molded body of the display panel for a vehicle may be damaged in appearance due to sink marks or the like after molding. If the appearance is damaged due to a defect on the surface of the transparent resin molded body, the display panel for a vehicle may become a defective product because it is located in front of the driver and passengers. Furthermore, the instrument panel is a high-risk area for collisions involving the driver or occupants in traffic accidents, and automotive display panels placed on the instrument panel are expected to contribute to the protection of the driver and occupants in emergencies such as accidents. Moreover, automotive display panels require the suppression of reduced strength and the generation of abnormal noises caused by friction between various parts.

[0005] The object of the present invention is to provide an automotive display panel that does not reduce the strength and aesthetics of the automotive display panel, does not generate abnormal noise in the automotive display panel, and reduces light leakage, as well as an automotive display device equipped with such an automotive display panel. [Means for solving the problem]

[0006] Several embodiments for solving the problem are described below. These embodiments can be combined as needed. A method for manufacturing an automotive display device according to the first view of the present invention comprises an injection molding step, a groove forming step, and a filler forming step. The injection molding step involves injection molding a transparent resin molded body having a predetermined shape and transmitting light. The groove forming step involves forming grooves by cutting along a predetermined shape using computer numerical control, between a display area that displays information using light transmitted from the back surface to the front surface of the transparent resin molded body and the edge of the transparent resin molded body, and / or between adjacent display areas, leaving a predetermined thickness. The filler forming step involves filling the grooves with a colored resin that blocks light traveling through the transparent resin molded body to form a colored resin filler in the grooves. The first method for manufacturing an automotive display device includes a groove forming step and a filler forming step, so that grooves do not need to be formed by injection molding, thus preventing shrinkage and warping during groove formation. Furthermore, since a colored resin is filled into the grooves to form a colored resin filler, the transparent resin molded body around the grooves becomes integrated with the colored resin filler, reinforcing the transparent resin molded body with the colored resin filler. This suppresses the reduction in strength of the automotive display panel caused by groove formation and prevents the generation of abnormal noises in the automotive display panel due to vehicle vibration. The colored resin filler in the grooves reduces light leakage to the edges of the transparent resin molded body and / or to adjacent display areas.

[0007] A method for manufacturing an automotive display device according to the second view of the present invention is configured such that, in the method for manufacturing an automotive display device according to the first view, the predetermined range is 0.5 mm or more and 2 mm or less, and is 1 / 2 the thickness of the transparent resin molded body on both sides of the groove. According to the second method for manufacturing an automotive display device, it is possible to appropriately adjust the reduction of light leakage and the suppression of a decrease in the intensity of the automotive display panel.

[0008] A method for manufacturing an automotive display device according to the third view of the present invention, in the method for manufacturing an automotive display device according to the first or second view, comprises a thinning step in which the display area of ​​a transparent resin molded body is thinned to a predetermined shape by cutting using computer numerical control. According to the third-party method for manufacturing automotive display devices, the difficulties in molding due to the fluidity of the resin, such as in injection molding, are eliminated, making molding easier. Furthermore, by thinning the display area using computer numerical control machining, the difficulties in molding due to the fluidity of the resin are eliminated, and shrinkage and warping of the display area can be prevented.

[0009] A method for manufacturing an automotive display device according to the fourth view of the present invention comprises a bonding step in which a display is bonded to a portion that has been thinned by cutting in the thinning step using an optically transparent resin or an optically transparent adhesive, in the method for manufacturing an automotive display device according to the third view. According to the manufacturing method for automotive display devices from the fourth viewpoint, the visibility of the display can be improved by bonding an optical transparent resin or optical transparent adhesive to the portion of the transparent resin molded body that has been thinned by machining.

[0010] The method for manufacturing an automotive display device according to the fifth view of the present invention is configured such that, in the method for manufacturing an automotive display device according to the fourth view, the refractive index of the optical transparent resin or optical transparent adhesive is greater than or equal to the value obtained by subtracting 0.1 from the refractive index of the transparent resin molded article and less than or equal to the value obtained by adding 0.1 to the refractive index of the transparent resin molded article. According to the manufacturing method for automotive display devices of the fifth viewpoint, by setting the refractive index of the optical transparent resin or optical transparent adhesive to a value greater than or equal to the refractive index of the transparent resin molded body 21 minus 0.1 and less than or equal to the refractive index of the transparent resin molded body 21 plus 0.1, the visibility of the display can be improved compared to when the refractive index is set outside this range.

[0011] An automotive display panel according to the sixth view of the present invention comprises a transparent resin molded body that transmits light and has a predetermined shape and grooves formed by cutting along the predetermined shape, and a colored resin filler made of a colored resin that fills the grooves and blocks light traveling through the transparent resin molded body. The transparent resin molded body has a display area that displays information using light transmitted from the back surface to the front surface. The grooves are arranged between the display area and the edges of the transparent resin molded body and / or between adjacent display areas. The thickness of the groove portion of the transparent resin molded body is 0.5 mm or more and 2 mm or less, and is less than or equal to half the thickness of the transparent resin molded body on both sides of the groove. In the sixth perspective, the automotive display panel has grooves formed by machining, which prevents shrinkage and warping during groove formation. Furthermore, since the grooves are filled with colored resin to form a colored resin filler, the transparent resin molded body around the grooves integrates with the colored resin filler, reinforcing the transparent resin molded body. This suppresses the reduction in strength of the automotive display panel caused by groove formation and prevents the generation of abnormal noises in the automotive display panel due to vehicle vibration. The colored resin filler in the grooves reduces light leakage to the edges of the transparent resin molded body and / or to adjacent display areas. In addition, it is possible to appropriately adjust the reduction of light leakage and the suppression of the reduction in strength of the automotive display panel. The automotive display panel according to the seventh view of the present invention is an automotive display panel according to the sixth view, wherein the transparent resin molded body has a display area that is thinner than the surrounding area due to machining. According to the seventh perspective on automotive display panels, it is possible to prevent shrinkage and warping in the display area and to give the display area a good aesthetic appearance.

[0012] An automotive display device according to the eighth view of the present invention comprises a transparent resin molded body that transmits light and has a predetermined shape and grooves formed by cutting along the predetermined shape; a colored resin filler made of a colored resin that fills the grooves and blocks light traveling through the transparent resin molded body; and a light source disposed on the back side of the transparent resin molded body and emitting light that passes through the transparent resin molded body. The transparent resin molded body has a display area that displays information using light transmitted from the back to the front. The grooves are located between the display area and the end of the transparent resin molded body and / or between adjacent display areas. The thickness of the groove portion of the transparent resin molded body is 0.5 mm or more and 2 mm or less, and is less than or equal to half the thickness of the transparent resin molded body on both sides of the groove. In the automotive display device from the eighth perspective, since the grooves are formed by machining, shrinkage and warping during groove formation can be prevented. Furthermore, since the grooves are filled with colored resin to form a colored resin filler, the transparent resin molded body surrounding the grooves integrates with the colored resin filler, reinforcing the transparent resin molded body with the colored resin filler. This suppresses the reduction in strength of the automotive display device caused by the formation of the grooves and prevents the generation of abnormal noises in the automotive display device due to vehicle vibrations. The colored resin filler in the grooves reduces the amount of light leaking to the edges of the transparent resin molded body and / or to adjacent display areas. In addition, it is possible to appropriately adjust the reduction of light leakage and the suppression of the reduction in strength of the automotive display device. The automotive display device according to the ninth view of the present invention is an automotive display device according to the eighth view, wherein the transparent resin molded body has a display area that is thinner than the surrounding area due to machining. It is equipped with an optical transparent resin or optical transparent adhesive for bonding a display that is displayed by a light source to the thin portion of the display area. According to the automotive display device from the ninth perspective, it is possible to prevent shrinkage and warping in the display area and to give the display area a good aesthetic appearance. In addition, the visibility of the display can be improved by bonding an optical transparent resin or optical transparent adhesive to the thinned portion of the transparent resin molded body that has been machined. [Effects of the Invention]

[0013] The method for manufacturing an automotive display device according to the present invention provides an automotive display device that does not reduce the strength and aesthetics of the automotive display panel, does not generate abnormal noises in the automotive display panel, and reduces light leakage in the automotive display panel. The automotive display panel or automotive display device according to the present invention can reduce light leakage while preventing a decrease in strength and aesthetics and the generation of abnormal noises. [Brief explanation of the drawing]

[0014] [Figure 1]It is a schematic front view of an instrument panel for explaining the arrangement of a vehicle display device on the instrument panel. [Figure 2] It is a perspective view showing an example of the configuration of a vehicle display panel according to the first embodiment. [Figure 3] It is a cross-sectional view of a vehicle display panel cut along the line I-I of FIG. 2. [Figure 4] It is a cross-sectional view of a vehicle display panel cut along the line II-II of FIG. 2. [Figure 5] It is a flowchart showing an example of the manufacturing flow of a vehicle display device according to the first embodiment. [Figure 6] It is a cross-sectional view showing an example of the configuration of a vehicle display panel according to the second embodiment. [Figure 7] It is a cross-sectional view showing an example of the configuration of a vehicle display panel according to the third embodiment. [Figure 8] It is a flowchart showing an example of the manufacturing flow of a vehicle display device according to the third embodiment. [Figure 9] It is a cross-sectional view showing an example of the configuration of a vehicle display panel according to the fourth embodiment. [Figure 10] It is a cross-sectional view showing an example of the configuration of a vehicle display panel according to the fifth embodiment.

Mode for Carrying Out the Invention

[0015] <First Embodiment> (1) Configuration of Vehicle Display Device In FIG. 1, an instrument panel 10 of a vehicle is shown. Meters such as a speedometer 11 are installed on the instrument panel 10. The instrument panel 10 also includes a dashboard 12. A steering wheel 90 is arranged in front of the instrument panel 10. A car display panel 20 is located in the center of the instrument panel 10. The car display panel 20 is, for example, a component of the navigation system. Below the car display panel 20 is a heater control panel 30. When controlling the cooling system, the term "air conditioning control panel" may be used instead of "heater control panel." The heater control panel 30 displays, for example, a temperature setting icon, a heater symbol, a mode switching icon, and a power icon. The temperature setting icon is, for example, an icon showing a number or arrow indicating the temperature. The heater symbol is a symbol represented by a wavy line design. The heater symbol indicates, for example, that the heater is operating. The mode switching icon is an icon that indicates the switching of the heater mode (heating, cooling, fan). The power icon is an icon that indicates whether the heater is powered on or off.

[0016] (1-1) Automotive display panel An example of an automotive display panel 20 is shown in Figure 2. The automotive display panel 20 comprises a transparent resin molded body 21 and a colored resin filler 22, as shown in Figures 3 and 4. Figure 3 shows the cross-sectional shape cut along line II in Figure 2, and Figure 4 shows the cross-sectional shape cut along line II-II in Figure 2. In the center of the automotive display panel 20, as viewed from the front, is a trapezoidal transparent first display area AR11 made of a transparent resin molded body 21, and below the first display area AR11 are a roughly rectangular second display area AR12 and a third display area AR13. Between the second display area AR12 and the third display area AR13 is an opening 25, in which, for example, a knob is placed. As viewed from the front, a light-shielding area AR2 is arranged around the display areas AR11, AR12, and AR13 to prevent light from passing through. The transparent resin molded body 21 has a predetermined shape. Here, the predetermined shape is a rectangle when viewed from the front, with a cross-section that is curved in an arc shape and has an opening 25. The transparent resin molded body 21 has grooves 23 formed by cutting. The grooves 23 follow the predetermined shape of the transparent resin molded body 21. In other words, the grooves 23 shown in Figures 3 and 4 are curved in an arc shape along the surface of the curved transparent resin molded body 21. Here, the grooves 23 follow a simple curved shape, but the predetermined shape that the grooves 23 follow may be a complex three-dimensional shape that combines many curves and surfaces rather than simple basic shapes such as a flat plate and a curved shape. The transparent resin molded body 21 is made of transparent resin and transmits light. The transparent resin molded body 21 may be semi-transparent.

[0017] The colored resin filler 22 consists of colored resin filled into the groove 23. The colored resin filler 22, made of colored resin, can block light traveling through the transparent resin molded body 21. Since such a colored resin filler 22 is arranged along a predetermined shape of the transparent resin molded body 21, it can reduce light leaking from the edges 21E of the transparent resin molded body 21. The colored resin filler 22 is firmly bonded to the transparent resin molded body 21 because it is filled into the groove 23. In other words, the colored resin filler 22 is integrated with the transparent resin molded body 21. Because the colored resin filler 22 and the transparent resin molded body 21 are integrated, even if stress is applied to the transparent resin molded body 21 due to, for example, the vibration of the automobile, no displacement occurs between the colored resin filler 22 and the transparent resin molded body 21, thus preventing the generation of abnormal noise associated with the vibration of the automobile. Furthermore, because the stress is distributed between the colored resin filler 22 and the transparent resin molded body 21, stress does not concentrate on the part of the transparent resin molded body 21 that is thinned by the groove 23, thus preventing a decrease in the strength and aesthetics of the automotive display panel 20 of the transparent resin molded body 21 even though the groove 23 is formed. The display areas AR11, AR12, and AR13 of the transparent resin molded body 21 are areas where a display is made using light transmitted from the back surface BS to the front surface FS. The groove 23 is located between the display areas AR11, AR12, and AR13 and the end portion 21E.

[0018] The thickness TH1 of the groove 23 portion of the transparent resin molded body 21 is 0.5 mm or more and 2 mm or less, and is set to be less than or equal to half the thickness TH2 of the transparent resin molded body 21 on both sides of the groove 23. The width of the groove 23 is, for example, 1 mm or more and 5 mm or less. The automotive display panel 20 shown in Figures 2 to 4 includes a partial light-shielding film 26. The partial light-shielding film 26 is transparent in the portion corresponding to the display areas AR11, AR12, and AR13, and colored, for example, black, in the portion corresponding to the light-shielding area AR1. The light-shielding area AR1 only needs to be able to block light from emitting from the automotive display panel 20 from the back surface BS of the transparent resin molded body 21 to the front surface FS, so it may be colored with a color other than black. The light-shielding area AR1 is formed, for example, by printing ink over the entire surface of the light-shielding area AR1. The partial light-shielding film 26 is, for example, a decorative film. The partial light-shielding film 26 is provided on the surface FS of the transparent resin molded body 21 by insert molding during injection molding of the transparent resin molded body 21.

[0019] (1-2) Automotive display device The automotive display device 1 comprises an automotive display panel 20, a liquid crystal display 2, and a light source 3. The liquid crystal display 2 and the light source 3 are located on the back surface BS side of the transparent resin molded body 21. The light source 3 is the backlight of the liquid crystal display 2. Located on the back surface BS side means that they do not have to be in direct contact with the back surface BS of the transparent resin molded body 21. Of course, they may also be located in direct contact with the back surface BS of the transparent resin molded body 21. Light emitted from the light source 3 passes through the liquid crystal display 2 and the transparent resin molded body 21, and is emitted to the outside of the automotive display device 1 from the display areas AR11, AR12, and AR13. However, of the light emitted from the light source 3, the light that passes through the transparent resin molded body 21 and heads toward the edge 21E of the transparent resin molded body 21 is blocked by the colored resin filler 22, so the amount of light is reduced compared to when the colored resin filler 22 is not present. Instead of the liquid crystal display 2 and light source 3, a self-emissive display such as an organic light-emitting diode (OLED) display or a plasma display may be used. When using an OLED display or a plasma display, since they are self-emissive, they themselves act as light sources, eliminating the need to provide a separate light source.

[0020] (2) Method for manufacturing an automotive display device The manufacturing of the above-mentioned automotive display device 1 will be explained following the flowchart in Figure 5. In the injection molding process (step S1), the transparent resin molded body 21 is injection molded. The transparent resin molded body 21 formed in the injection molding process does not yet have grooves 23 formed on it. In other words, the predetermined shape of the transparent resin molded body 21 is the shape shown in Figures 2 to 4, excluding the grooves 23. The transparent resin molded body 21 is molded from a transparent resin and transmits light. Examples of transparent resins include polycarbonate resin (PC) and polymethyl methacrylate resin (PMMA). In the injection molding process, the partial light-shielding film 26 may be placed inside the mold and, by insert molding, provided on the surface FS of the transparent resin molded body 21 simultaneously with the injection molding. Alternatively, the partial light-shielding film 26 may be bonded to the surface FS of the transparent resin molded body 21 after injection molding. In the groove formation process (step S2), grooves 23 are formed by cutting along a predetermined shape of the transparent resin molded body 21 using computer numerical control (CNC) so as to leave a predetermined thickness TH1. By using computer numerical control, it is possible to form grooves 23 that follow the three-dimensional shape of the transparent resin molded body 21. In the transparent resin molded body 21 shown in Figures 3 and 4, grooves 23 are formed along a curved, arc-shaped form. For example, the thickness TH1 of the transparent resin molded body 21 in the part where grooves 23 are formed will be a constant thickness of, for example, 0.5 mm. Alternatively, the thickness TH1 of the transparent resin molded body 21 in the part where grooves 23 are formed may vary in the range of 0.5 mm to 1 mm, for example, if the thickness TH2 of the transparent resin molded body 21 around the grooves 23 is 3 mm. The thickness TH2 of the transparent resin molded body 21 is, for example, 2 mm to 4 mm when the transparent resin molded body 21 is used in an automotive display device 1.

[0021] The thickness TH1 of the transparent resin molded body 21 in the portion where the groove 23 is formed is preferably 0.5 mm or more and 2 mm or less, and less than or equal to half the thickness TH2 of the transparent resin molded body on both sides of the groove 23. If the thickness TH1 of the transparent resin molded body 21 in the portion where the groove 23 is formed is thick, more light will leak from the edges 21E, etc. If the thickness TH1 of the transparent resin molded body 21 in the portion where the groove 23 is formed is thin, the rigidity of the automotive display panel 20 will decrease. The above-mentioned preferred range for the thickness TH1 is set considering the balance between these two factors. When grooves 23 are formed by injection molding, sink marks and warping may occur in the transparent resin molded body 21. However, when grooves 23 are formed by computer numerical control machining, sink marks and warping can be prevented. The grooves 23 are formed at least between the display areas AR11, AR12, AR13 and the end portion 21E of the transparent resin molded body 21, and between adjacent display areas AR11, AR12, AR13. In this first embodiment, for example, the grooves 23 are formed around the entire perimeter of the display area AR11. However, for example, if measures are taken to prevent light from leaking from the top of the automotive display panel 20 from being radiated into the vehicle interior by other sealing members, the formation of grooves on the top of the display area AR11 may be omitted. In the filler formation process (step S3), a colored resin is filled into the groove 23 to form a colored resin filler 22. The colored resin has the function of blocking light traveling through the transparent resin molded body 21 from the display areas AR11, AR12, AR13 to the end 21E and / or toward adjacent display areas AR11, AR12, AR13. Light toward adjacent display areas refers to light traveling from display area AR11 toward display areas AR12, AR13, light traveling from display area AR12 toward display areas AR11, AR13, and light traveling from display area AR13 toward display areas AR11, AR12.

[0022] Colored resins are resins that have been colored by mixing colorants into them. Colorants include pigments and dyes. The resins that make up colored resins include thermoplastic resins, thermosetting resins, and UV-curing resins. Examples of thermoplastic resins include polypropylene resin. Examples of thermosetting resins include urethane resin. Examples of UV-curing resins include acrylic resin. As a material for colored resins, thermoplastic resins have excellent processability because they soften with heat, it is easy to uniformly mix pigments into them to achieve a uniform color distribution, and they are suitable for recycling because they can be softened with heat and remolded. In the assembly process (step S4), the automotive display device 1 is assembled. In the assembly process, the liquid crystal display 2 and the light source 3 are combined with the automotive display panel 20. Alternatively, other displays and light sources, such as an organic EL display or a plasma display, can be used instead of the liquid crystal display 2 and the light source 3.

[0023] <Second Embodiment> (3) Configuration and manufacturing of automotive display devices In the first embodiment, a case was described in which various information and images are displayed using a liquid crystal display 2, an organic EL display, or a plasma display. However, in automotive display devices 1, some displays are made by switching between being lit and not lit, such as the icons on the heater control panel 30. Figure 6 shows that the partial light-shielding film 26 of the display areas AR14, AR15, AR16, and AR17 of the automotive display device 1 according to the second embodiment is printed with a design that allows light to pass through only the icon. On the back side BS, four LEDs 3L corresponding to the display areas AR14, AR15, AR16, and AR17 are arranged as light sources 3. A power icon is placed in the display area AR14, and when the LED 3L corresponding to the display area AR14 lights up, the power icon lights up. The illumination of the power icon informs the driver that the heater is on. In the automotive display panel 20 of the automotive display device 1 of the second embodiment, similar to the first embodiment, a colored resin filler 22 (groove 23) is placed between adjacent display areas AR14, AR15, AR16, and AR17. Furthermore, a colored resin filler 22 (groove 23) is placed between the display areas AR14 and AR17 and the end portion 21E of the transparent resin molded body 21. For example, even when the power icon lights up, the colored resin filler 22 is placed between the display area AR14 of the power icon and the adjacent display area AR15, so that the light needed to light up the power icon does not leak into the display area AR15. Since the automotive display device 1 of the second embodiment can be manufactured using the same manufacturing flow as the automotive display device 1 of the first embodiment, the description of the manufacturing method of the automotive display device 1 of the second embodiment will be omitted here.

[0024] <Third Embodiment> (4) Configuration and manufacturing of automotive display devices In the automotive display device 1 of the first embodiment described above, the shape of the transparent resin molded body 21 in the area where the liquid crystal display 2 and light source 3 are arranged remains the same as the shape formed by injection molding. An example of the configuration of the automotive display device 1 according to the third embodiment is shown in Figure 7. As shown in Figure 7, in the automotive display device 1 according to the third embodiment, the transparent resin molded body 21 of the display area AR11 corresponding to the area where the liquid crystal display 2 and light source 3 are arranged is made thinner than the surrounding area RN1 of the display area AR11 by cutting using computer numerical control. In other words, the equation (thickness TH3 of the transparent resin molded body 21 in the thinned portion P1 corresponding to the display area AR11) < (thickness TH4 of the surrounding area RN1 of the display area AR11) holds true. The thickness TH4 of the periphery RN1 around the display area AR11 is, for example, 2 mm to 4 mm when the transparent resin molded body 21 is used in an automotive display device 1. Also, the difference (TH4-TH3) between the thickness TH3 of the thin-walled portion P1 of the transparent resin molded body 21 and the thickness TH4 of the periphery RN1 around the display area AR11 is, for example, 0.5 mm to 2 mm. In Figure 7, the wall between the periphery RN1 of the display area AR11 and the thin-walled portion P1 is depicted as being inclined, but this wall may be formed perpendicular to the surface of the thin-walled portion P1 or the surface of the periphery RN1. If the wall is perpendicular, it is convenient for accumulating the fluid OCR, and for example, it becomes easier to bond the liquid crystal display 2. Figure 8 shows the manufacturing flow of the automotive display device 1 according to the third embodiment. The difference between the manufacturing flow of the automotive display device 1 according to the third embodiment and the manufacturing flow of the first embodiment shown in Figure 5 is that it includes a thinning step (step S2'). In the thinning process, similar to the groove formation process (step S2), the display area AR11 of the transparent resin molded body 21 is thinned according to a predetermined shape by cutting using computer numerical control (CNC). Here, the case in which the thinning process (step S2') is performed after the groove formation process (step S2) has been described, but the order in which these processes are performed may be changed. Thinning a wide area such as the display area AR11 is difficult because the transparent resin molded body 21 is originally thin, for example, 3 mm thick, and the fluidity of the resin makes molding difficult. Thinning the display area AR11 by injection molding may cause sink marks and warping in the transparent resin molded body 21. In contrast, thinning the display area AR11 by computer numerical control machining eliminates the molding difficulties caused by the fluidity of the resin and prevents the occurrence of sink marks and warping.

[0025] <Fourth Embodiment> (5) Configuration and manufacturing of automotive display devices In the third embodiment of the automotive display device 1, the case in which the liquid crystal display 2 and light source 3 are arranged on the back surface BS of the thinned transparent resin molded body 21 has been described. In the third embodiment, cutting marks remain on the back surface BS of the thinned transparent resin molded body 21. In the automotive display device 1 of the third embodiment, the cut portion is polished to remove the cutting marks. Alternatively, in the automotive display device 1 of the third embodiment, a coating agent is applied to the cut portion to remove the cutting marks. However, in the automotive display device 1 of the third embodiment, a layer of air is interposed between the liquid crystal display 2 and light source 3 and the back surface BS of the transparent resin molded body 21. In the automotive display device 1 of the fourth embodiment, an optical clear resin 41 or optical clear adhesive 42 is placed between the portion P1, which has become thinner than the surrounding area AR11 due to machining, and the liquid crystal display 2 (see Figure 9). The optical clear resin 41 or optical clear adhesive 42 placed in the machining marks penetrates into the irregularities of the machining marks, preventing diffuse reflection caused by the machining marks. Comparing the optical clear resin 41 and the optical clear adhesive 42, the optical clear resin 41 is preferable for use in the machined portion of the transparent resin molded body 21 because it has higher fluidity and a better effect in filling machining marks. However, the optical clear adhesive 42 is superior in terms of workability because it is an adhesive processed into a tape form. Also, since the liquid crystal display 2 and the optical clear resin 41 or optical clear adhesive 42 are in close contact, no reflection occurs at the interface between air and resin, and the decrease in the amount of light from the liquid crystal display 2 toward the surface FS of the automotive display panel 20 is suppressed. As a result, it is possible to prevent a decrease in visibility due to cutting marks.

[0026] To prevent a decrease in visibility, it is preferable that the refractive index of the optical transparent resin 41 or optical transparent adhesive 42 is within plus or minus 0.1 of the refractive index of the transparent resin molded body 21 (refractive index of transparent resin molded body 21 -0.1 ≤ refractive index of optical transparent resin 41 or optical transparent adhesive 42 ≤ refractive index of transparent resin molded body 21 +0.1). For example, if the transparent resin molded body 21 is polycarbonate resin (refractive index 1.58), it is preferable to use an optical transparent resin 41 or optical transparent adhesive 42 with a refractive index of 1.48 to 1.68 for bonding the transparent resin molded body 21 to the liquid crystal display 2. For example, if the transparent resin molded body 21 is polymethyl methacrylate resin (refractive index 1.49), it is preferable to use an optical transparent resin 41 or optical transparent adhesive 42 with a refractive index of 1.39 to 1.59 for bonding the transparent resin molded body 21 to the liquid crystal display 2. The optical transparent resin 41 or optical transparent adhesive 42 is used in the assembly process (step S4) shown in Figure 8 to bond the liquid crystal display 2 to the thinned portion P1 of the optical transparent resin 41. The bonding process involves bonding the liquid crystal display 2 to the thinned portion P1, which has been thinned by cutting in the thinning process, using the optical transparent resin 41 or optical transparent adhesive 42. After assembly, the optical transparent resin 41 or optical transparent adhesive 42 adheres tightly to both the liquid crystal display 2 and the optical transparent resin 41. Furthermore, even when an organic EL display or plasma display is used instead of the liquid crystal display 2, the organic EL display or plasma display can be bonded to the transparent resin molded body 21 with the optical transparent resin 41 or the optical transparent adhesive 42.

[0027] <Fifth Embodiment> (6) Configuration and manufacturing of automotive display devices Figure 10 shows an example of the configuration of an automotive display device according to the fifth embodiment. The difference between the automotive display device 1 shown in Figure 10 and the automotive display device 1 of the fourth embodiment shown in Figure 9 is that a boss 50 is provided on the back surface BS of the transparent resin molded body 21, and the transmittance is adjusted so that the boss 50 is difficult to see from outside the automotive display panel 20. The structure provided on the back surface BS of the transparent resin molded body 21 may be something other than the boss 50, for example, a rib or a clip seat. In order to make the structure provided on the back surface BS of the transparent resin molded body 21 difficult to see, at least one of a pigment and a colorant is added to the transparent resin molded body 21. The preferred range of total light transmittance for making the structure provided on the back surface BS of the transparent resin molded body 21 difficult to see is 20% or more and 70% or less. The total light transmittance is measured in accordance with JIS K7375. The automotive display device 1 of the fifth embodiment can be manufactured using the same manufacturing flow as the automotive display device 1 of the fourth embodiment, except that the resin and mold used for the transparent resin molded body 21 are different. Therefore, the description of the manufacturing method of the automotive display device 1 of the fifth embodiment will be omitted here.

[0028] (7) Variant In the embodiments described above, the focus has been on cases where the automotive display device 1 has a function solely for displaying information. However, the automotive display device 1 may also be equipped with a touch sensor and have the function of an input device simultaneously with displaying information. The touch sensor is positioned in a location where input can be made by touching the automotive display panel 20. The touch sensor is positioned, for example, on the front surface FS or back surface BS of the transparent resin molded body 21. When positioned on the front surface FS of the transparent resin molded body 21, for example, the touch sensor is positioned between the transparent resin molded body 21 and the partially light-shielding film 26. When positioned on the back surface BS of the transparent resin molded body 21, for example, the touch sensor is positioned between the transparent resin molded body 21 and the liquid crystal display 2.

[0029] (8) Characteristics (8-1) The manufacturing method for the automotive display device 1 according to the first to fifth embodiments described above includes a groove forming step of forming grooves 23 between display areas AR11 to AR17 and the end portion 21E of the transparent resin molded body 21, and / or between adjacent display areas AR11 to AR17, by cutting along a predetermined shape while leaving a predetermined thickness, using computer numerical control, and a filler forming step of filling the grooves 23 with colored resin to form a colored resin filler 22 in the grooves 23. As a result, since the grooves 23 are not formed by injection molding, shrinkage and warping during groove formation can be prevented. Furthermore, since colored resin is filled into the grooves 23 to form a colored resin filler 22, the transparent resin molded body 21 around the grooves 23 becomes integrated with the colored resin filler 22, and the transparent resin molded body 21 is reinforced by the colored resin filler 22. As a result, a decrease in the strength and aesthetics of the automotive display panel 20 due to the formation of grooves 23 can be suppressed, and the generation of abnormal noise due to vehicle vibration can be prevented. Furthermore, the colored resin filler 22 in the groove 23 reduces the amount of light leaking to the edges 21E of the transparent resin molded body 21 and / or to the adjacent display areas AR11 to AR17.

[0030] (8-2) By making the thickness TH1 (see Figure 4) of the transparent resin molded body 21 left when forming the groove 23 0.5 mm or more and 2 mm or less, and less than or equal to half the thickness TH2 (see Figure 4) of the transparent resin molded body 21 on both sides of the groove 23, it is possible to appropriately adjust the reduction of light leakage and the suppression of a decrease in the strength of the automotive display panel 20. (8-3) As described in the third and fourth embodiments, when the display area AR11 of the transparent resin molded body 21 is thinned along a predetermined shape by cutting using computer numerical control, the molding difficulties caused by the fluidity of the resin, as in injection molding, are eliminated, making molding easier. Furthermore, by thinning the display area AR11 using computer numerical control cutting, the molding difficulties caused by the fluidity of the resin are eliminated, and shrinkage and warping of the display area AR11 can be prevented.

[0031] (8-4) As described in the fourth embodiment, by bonding, for example, a liquid crystal display 2, an organic EL display, or a plasma display to a portion P1 of the transparent resin molded body 21 that has been thinned by cutting, using an optical transparent resin 41 or an optical transparent adhesive 42, the visibility of the display can be improved. (8-5) It is preferable to set the refractive index of the optical transparent resin 41 or optical transparent adhesive 42 to be greater than or equal to the refractive index of the transparent resin molded body 21 minus 0.1, and less than or equal to the refractive index of the transparent resin molded body 21 plus 0.1. By setting the refractive index of the optical transparent resin 41 or optical transparent adhesive 42 within such a range, the visibility of the display can be improved. Although the first to fifth embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention. In particular, the multiple embodiments and modifications described herein can be arbitrarily combined as needed. [Explanation of Symbols]

[0032] 1 Automotive display device 2 LCD display 3 light source 3L LED 20 Automotive display panels 21 Transparent resin molding 21E End 22 Colored resin filler 23 Groove 41 Transparent resin for optics 42 Optical transparent adhesive AR11~AR17 display area

Claims

1. An injection molding process for injection molding a transparent resin molded body having a predetermined shape and that transmits light, A groove forming step in which grooves are formed by cutting along a predetermined shape, such as leaving a predetermined thickness, between a display area on which a display is made by light transmitted from the back surface to the front surface of the transparent resin molded body and the edge of the transparent resin molded body, and / or between adjacent display areas, using computer numerical control cutting. A filler forming step is to fill the groove with a colored resin that blocks light passing through the transparent resin molded body to form a colored resin filler in the groove. A method for manufacturing an automotive display device, comprising the following:

2. The predetermined range is 0.5 mm or more and 2 mm or less, and is less than or equal to half the thickness of the transparent resin molded body on both sides of the groove. A method for manufacturing an automotive display device according to claim 1.

3. The transparent resin molded body is further processed into a thin-walled state by cutting the display area to conform to the predetermined shape using computer numerical control. A method for manufacturing an automotive display device according to claim 1 or claim 2.

4. The thinning process includes a bonding step in which a display is bonded to the thinned portion by cutting using an optical clear resin or an optical clear adhesive. The method for manufacturing an automotive display device according to claim 3.

5. The refractive index of the optical transparent resin or the optical transparent adhesive is greater than or equal to the refractive index of the transparent resin molded article minus 0.1, and less than or equal to the refractive index of the transparent resin molded article plus 0.

1. A method for manufacturing an automotive display device according to claim 4.

6. A transparent resin molded body having a predetermined shape and grooves along the predetermined shape, which transmits light, A colored resin filler, which is filled in the groove and consists of a colored resin that blocks light from passing through the transparent resin molded body, Equipped with, The transparent resin molded body has a display area that displays information using light transmitted from the back surface to the front surface, The groove is located between the display area and the end of the transparent resin molded body and / or between adjacent display areas. An automotive display panel wherein the thickness of the groove portion of the transparent resin molded body is 0.5 mm or more and 2 mm or less, and is less than or equal to half the thickness of the transparent resin molded body on both sides of the groove.

7. The transparent resin molded body has a display area that is thinner than the surrounding area. The automotive display panel according to claim 6.

8. A transparent resin molded body having a predetermined shape and grooves along the predetermined shape, which transmits light, A colored resin filler, which is filled in the groove and consists of a colored resin that blocks light from passing through the transparent resin molded body, A light source is positioned on the back side of the transparent resin molded body and emits light that passes through the transparent resin molded body. Equipped with, The transparent resin molded body has a display area that displays information using light transmitted from the back surface to the front surface, The groove is located between the display area and the end of the transparent resin molded body and / or between adjacent display areas. Automotive display device, wherein the thickness of the groove portion of the transparent resin molded body is 0.5 mm or more and 2 mm or less, and is less than or equal to half the thickness of the transparent resin molded body on both sides of the groove.

9. The transparent resin molded body has a display area that is thinner than the surrounding area. The system includes an optical clear resin or optical clear adhesive for bonding the display, which is shown by the light source, to the thin portion of the display area. The automotive display device according to claim 8.

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