TOUCH-TYPE BUTTON FOR VEHICLE

Abstract

A touch-type button for a vehicle may include: a hidden cover defining an external appearance of the touch-type button and having a pattern which corresponds to a letter font; and a transparent electrode attached to a rear surface of the hidden cover and configured to generate a signal in response to a change in capacitance, wherein the transparent electrode transmits light emitted from a light source disposed behind thereof to allow the letter font to be revealed and recognized.

Claims

1. A touch-type button for a vehicle, comprising; a hidden cover defining an external appearance of the touch-type button and having a pattern which corresponds to a letter font; and a transparent electrode attached to a rear surface of the hidden cover and configured to generate a signal in response to a change in capacitance, wherein the transparent electrode transmits light emitted from a light source disposed behind the transparent electrode to allow the letter font to be revealed and recognized.

2. The touch-type button of claim 1, wherein the hidden cover comprises; a black film in which a portion corresponding to the letter font is cut; and a smoky resin injection molded product attached to the black film and containing a polycarbonate base to which a black coloring agent and a light diffusing additive are added.

3. The touch-type button of claim 2, wherein the hidden cover has a thickness of 1 to 3 mm.

4. The touch-type button of claim 2, wherein the hidden cover has transmissivity of 30 to 45%.

5. The touch-type button of claim 4, wherein the hidden cover has turbidity of 90% or more.

6. The touch-type button of claim 4, wherein the hidden cover has brightness (L*) of less than 70.

7. The touch-type button of claim 2, wherein the transparent electrode has a thickness of less than 150 m.

8. The touch-type button of claim 7, wherein the transparent electrode has transmissivity of 85% or more.

9. The touch-type button of claim 8, wherein the transparent electrode has turbidity of less than 2%.

10. The touch-type button of claim 8, wherein the transparent electrode has yellowness (b*) of less than 2.

11. The touch-type button of claim 8, wherein the transparent electrode has a surface resistance of less than 200.

12. The touch-type button of claim 2, further comprising a light diffusing film attached to the transparent electrode.

13. The touch-type button of claim 12, wherein the light diffusing film has transmissivity of 85% or more and turbidity of 90% or more.

14. A touch-type button for a vehicle, comprising: a hidden cover defining an external appearance of the touch-type button and comprising: a black film in which a portion corresponding to a letter font is cut; and a smoky resin injection molded product attached to the black film and containing a polycarbonate base to which a black coloring agent and a light diffusing additive are added; and a transparent electrode attached to a rear surface of the hidden cover and configured to generate a signal in response to a change in capacitance, wherein the hidden cover has transmissivity of 30 to 45%, and the transparent electrode has transmissivity of 85% or more.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIGS. 1, 2, 3A, 3B, 4, 5, 6A, 6B, 7A, and 7B are diagrams showing a method of manufacturing a conventional button for a vehicle and a problem thereof.

[0034] FIG. 8 is a diagram showing an operating method of a touch-type button for a vehicle according to an exemplary embodiment of the present disclosure.

[0035] FIGS. 9A and 9B are diagrams illustrating the results of the touch-type button for the vehicle according to an exemplary embodiment of the present disclosure which is implemented by the method shown in FIG. 8.

[0036] FIG. 10 is a diagram schematically illustrating the touch-type button for the vehicle according to an exemplary embodiment of the present disclosure.

[0037] FIGS. 11 and 12 are diagrams illustrating one configuration of the touch-type button for the vehicle according to an exemplary embodiment of the present disclosure.

[0038] FIG. 13 is a diagram illustrating a method of evaluating the touch-type button for the vehicle according to an exemplary embodiment of the present disclosure.

[0039] FIG. 14 is a diagram showing a composition of a hidden cover of the touch-type button for the vehicle according to an exemplary embodiment of the present disclosure.

[0040] FIGS. 15A to 15D are diagrams showing embodiments according to transmissivities of the touch-type button for the vehicle according to an exemplary embodiment of the present disclosure.

[0041] FIGS. 16A and 16B are diagrams for comparing differences in illumination according to applications of a touch film.

[0042] FIG. 17 is a diagram schematically illustrating a touch-type button for a vehicle in accordance with another exemplary embodiment of the present disclosure.

DESCRIPTION OF SPECIFIC EMBODIMENTS

[0043] In order to fully understand the present disclosure, operational advantages of the present disclosure and objects achieved by implementing embodiments of the present disclosure, reference should be made to the accompanying drawings illustrating exemplary embodiments of the present disclosure and the description on the accompanying drawings.

[0044] In describing exemplary embodiments of the present disclosure, a description on well-known technologies or a repetitive description which may unnecessarily obscure the gist of the present disclosure will be abbreviated or omitted.

[0045] FIG. 8 is a diagram showing an operating method of a touch-type button for a vehicle according to an exemplary embodiment of the present disclosure, and FIGS. 9A and 9B are diagrams illustrating the result of the touch-type button for the vehicle according to an exemplary embodiment of the present disclosure which is implemented by the method shown in FIG. 8.

[0046] In addition, FIG. 10 is a diagram schematically illustrating the touch-type button for the vehicle according to an exemplary embodiment of the present disclosure, and FIGS. 11 and 12 are diagrams illustrating one configuration of the touch-type button for the vehicle according to an exemplary embodiment of the present disclosure.

[0047] Below, the touch-type button for the vehicle according to one exemplary embodiment of the present disclosure is described with reference to FIGS. 8, 9A, 9B, 10, 11, and 12.

[0048] A conventional touch-type button for a vehicle adopts a simple method in which a font of button is appeared in white in the daytime and illumination is turned on only at night. According to the above, brightness of the night illumination should be thus low, because glare and light blur occur when illumination is bright. Therefore, the conventional touch-type button does not require high brightness.

[0049] On the contrary, in the present disclosure, a hidden function by which a font of letter is not visible as shown in FIG. 9A is realized in a state in which a vehicle has not started and illumination is turned off as shown in FIG. 8, and when the vehicle starts, the illumination is turned-on day and night as shown in FIG. 9B to allow the font of letter to be revealed by the illumination, and high brightness is thus needed.

[0050] As illustrated in FIG. 10, to this end, the touch-type button for the vehicle according to an exemplary embodiment of the present disclosure includes a hidden cover 10 and a transparent electrode, for example, an indium tin oxide (ITO) touch film 20. In addition, a transparent adhesive such as an optical clear adhesive (OCA) may be interposed between the hidden cover 10 and the ITO touch film.

[0051] The hidden cover 10 corresponds to an external appearance of the button which is exposed to the outside and allows a user to touch the hidden cover, and the transparent electrode is attached to a rear surface of the hidden cover 10, so that the amount of change in capacitance is transmitted through a printed circuit board (PCB) (not shown) connected to the transparent electrode, and a touch input is thus recognized.

[0052] The hidden cover 10 and the transparent electrode transmit light emitted from a light emitting diode (LED) 30, so that letter fonts patterned on the hidden cover 10 are brighter than surroundings thereof to enable the user to recognize the letter fonts.

[0053] Referring to FIG. 11, the hidden cover 10 is composed of an in-mold label (IML) film 11 and a smoky resin injection molded product 12.

[0054] The hidden cover 10 is manufactured by laser-cutting a black film in accordance with the letter fonts and then attaching the black film to the smoky resin injection molded product, which is a composition of polycarbonate (PC), black coloring agent and light diffusing additive, in an in-mold label (IML) process.

[0055] By configuring the hidden cover as above, the letter font is not exposed in the absence of illumination, and the illuminated region can be widened due to the high light transmittance of the transparent electrode. In addition, a conductor area is increased as shown in FIG. 12, and touch sensitivity can be thus enhanced more than twice.

[0056] The conditions of the hidden cover 10 and the transparent electrode of the present disclosure described above are summarized in Table 1, and the ITO touch film 20 was employed as an example of the transparent electrode.

TABLE-US-00001 TABLE 1 Hidden cover ITO touch film Thickness Transmissivity Turbidity Brightness Thickness Transmissivity Turbidity Yellowness Sheet (mm) (%) (%) (L*) (m) (%) (%) (b*) resistance () 1~3 30~45 90 Less Less 85 Less Less Less or than than or than than than more 70 150 more 2 2 200

[0057] First of all, a thickness of the hidden cover 10 may be 1 to 3 mm.

[0058] When the thickness of the hidden cover 10 is out of the above range and is less than 1 mm, flexure of the hidden may be occurred after performing an environmental durability test, and when the thickness of the hidden cover exceeds 3 mm, a distance between the electrode and the user's finger is increased, and so the touch performance may be degraded.

[0059] In addition, within this thickness range, the hidden cover should have transmissivity of 30 to 45%.

[0060] When transmissivity of the hidden cover 10 is less than 30%, the light transmittance of the LED is deteriorated, and brightness performance of the illumination is thus degraded. In addition, if the transmissivity exceeds 45%, even when the lighting is turned off, the font is recognized with the naked eye and a hidden characteristic is thus degraded, and a hot spot phenomenon, in which the illumination is brightly looked as a point light source due to a straight advancing property of the LED illumination, occurs to lower uniformity of the illumination.

[0061] Brightness can be determined according to the transmittance, and when the brightness L* exceeds 70, the font is also recognized with the naked eye and the hidden characteristic is thus degraded.

[0062] In addition, the LED light is not diffused well in a condition of turbidity of less than 90%, and therefore, there is a problem that uniformity of the illumination is deteriorated.

[0063] Next, the total thickness of the ITO touch film 20 should not exceed 150 m.

[0064] If the total thickness exceeds 150 m, durability of the ITO touch film may be degraded due to bending. In addition, transmissivity of the ITO touch film should be 85% or more in accordance with Japanese Industrial Standard (JIS)-K-7361 which is the internal standard, and turbidity should be less than 2% in accordance with JIS-K-7136.

[0065] When the transmissivity is less than 85%, light loss of the LED light is increased, and so brightness of the illumination may be deteriorated. If the turbidity is 2% or more, the brightness of the illumination may be deteriorated due to light scattering of the LED light.

[0066] Yellowness b* should be less than 2 in accordance with JIS-Z-8722 (Methods of colour measurementReflecting and transmitting objects).

[0067] If the yellowness is 2 or more, a color coordinate of the LED illumination color may be shifted due to yellowing of the film and the illumination color may be thus changed.

[0068] In addition, when surface resistance is 200 or more, touch performance may be degraded and it is thus desirable that surface resistance is less than 200.

[0069] In the case where the thickness, the brightness, the turbidity, the transmissivity of the hidden cover, and the thickness, the transmissivity, the turbidity, the yellowness and the surface resistance of the ITO touch film satisfy the above-mentioned conditions, a hidden function is realized when the illumination is turned off, and the light may be bright and uniform when the illumination is turned on and performance desired by the present disclosure can be achieved.

[0070] FIG. 13 schematically illustrates a method of evaluating the illumination emitted through the touch-type button for the vehicle according to an exemplary embodiment of the present disclosure using a two-dimensional imaging type luminance measuring instrument, and the light uniformity of illumination should be 60% or more.

[0071] In addition, the brightness at the button 1 which is 30 cm away from a lens of the measuring instrument should be more than 400 cd/m.sup.2 so that the touch-type button can be used in the daytime.

[0072] The present disclosure includes the hidden cover 10 and the ITO touch film 20 having the above-described conditions, thereby functioning as a button configured to transmit a touch input signal to a controller (not shown) through a user's operation.

[0073] In other words, the hidden cover 10 is a plastic insulator, and the touch film 20 made of ITO acts as an electrode. Basically, when a human's hand touches the electrode in a state where the electrode has constant capacitance, a touch signal is sensed by a change in capacitance.

[0074] Since as compared to a conventional flexible printed circuit board (FPCB), ITO has a large electrode area, ITO has a large capacitance and excellent touch sensitivity.

[0075] In addition, the hidden cover 10 is provided for preventing the font from being revealed in the absence of illumination, and as shown in FIG. 14, PC, which is base material of the hidden cover, contains black coloring agent and silicon dioxide (SiO.sub.x) light diffusing agent as an additive. The transmissivity of the hidden cover can be adjusted by adjusting the content of black coloring agent. This is because the black coloring agent prevents the light of the LED from being transmitted.

[0076] Thus, as shown in FIGS. 15A to 15D, the hidden characteristic may be realized in a proper transmissivity range of the hidden cover. In FIGS. 15A to 15D, a part shown on a background indicates a state in which the illumination is turned off, and another part shown on an upper right corner indicates a state in which the illumination is turned on.

[0077] In other words, FIG. 15A shows a case where the transmissivity is 8%, and it can be seen that the illumination performance is degraded (insufficient brightness). In addition, FIG. 15B shows a case where the transmissivity is 30% corresponding to the present disclosure, and it can be seen that a letter or a graphic is concealed and that the brightness and uniformity of illumination are satisfied.

[0078] In addition, FIG. 15C shows a case where the transmissivity is 51%, and it can be seen that the letter and the graphic are not concealed. FIG. 15D shows a case where the transmissivity is 73%, and it can be seen that the letter and the graphic are not concealed and a hot spot occurs in the illumination.

[0079] In addition, since the light of the LED has the straight advancing property, the light diffusing agent is added. By adjusting an addition of the light diffusing agent, the optimum transmissivity range, turbidity range and brightness value of the hidden cover were derived.

[0080] Even when the same hidden cover is applied, a characteristic of illumination is varied depending on the type of the touch film. FIG. 16A shows a case in which a conventional FPCB type touch switch is used, an uneven phenomenon of the illumination occurs due to the LED light going straight through a perforated hole.

[0081] On the contrary, in the case where the ITO touch film of the present disclosure is employed as shown in FIG. 16B, while the light passes through a transparent wide area of ITO, diffusion/scattering of the light through the film occurs, and the uniformity of illumination is thus improved by the light diffusion effect caused by the above.

[0082] The characteristics derived from the experimental results according to characteristic ranges of the hidden cover and the electrode of the present disclosure are summarized in the following tables together with comparative examples. Table 2 shows Example and Comparative examples, and Table 3 shows experimental results.

TABLE-US-00002 TABLE 2 Cover Electrode A A Material (mm) B C D Material (m) B C E F G Comparative White 1.5 40 99 55 ITO 150 89 0.43 1.7 150 Example 1 resin Comparative White 1.5 40 99 55 FPCB 150 Example 2 resin Example 1 Smoky 1.5 40 99 55 ITO 150 89 0.42 1.7 150 resin Comparative Smoky 0.5 53 99 55 ITO 150 89 0.42 1.7 150 Example 3 resin Comparative Smoky 4 40 99 55 ITO 150 89 0.42 1.7 150 Example 4 resin Comparative Smoky 1.5 20 99 55 ITO 150 89 0.42 1.7 150 Example 5 resin Comparative Smoky 1.5 50 99 55 ITO 150 89 0.42 1.7 150 Example 6 resin Comparative Smoky 1.5 43 80 55 ITO 150 89 0.42 1.7 150 Example 7 resin Comparative Smoky 1.5 30 99 88 ITO 150 89 0.42 1.7 150 Example 8 resin Comparative Smoky 1.5 40 99 55 FPCB 150 89 0.42 1.7 150 Example 9 resin Comparative Smoky 1.5 40 99 55 ITO 200 89 0.42 1.7 150 X Example 10 resin Comparative Smoky 1.5 40 99 55 ITO 150 80 0.42 1.7 150 Example 11 resin Comparative Smoky 1.5 40 99 55 ITO 150 86 3 1.7 150 Example 12 resin Comparative Smoky 1.5 40 99 55 ITO 150 89 0.42 3.6 150 Example 13 resin Comparative Smoky 1.5 40 99 55 ITO 150 89 0.42 1.7 250 Example 14 resin

[0083] Here, in Table 2, A indicates Thickness (mm), B indicates Transmissivity (%), C indicates Turbidity (%), D indicates Brightness (L*), E indicates Yellowness (b*), F indicates Sheet resistance (), and G indicates whether flexibility is satisfied.

TABLE-US-00003 TABLE 3 Whether Whether change in color touch Whether Luminance Uniformity of illumination reaction font is (Cd/m.sup.2) (%) is satisfied is satisfied hidden Comparative 2 58 X example 1 Comparative 2.5 51 X example 2 Example 1 417 70 Comparative 451 43 X example 2 Comparative 233 71 example 4 Comparative 348 73 example 5 Comparative 564 53 X example 6 Comparative 449 58 example 7 Comparative 387 71 X example 8 Comparative 374 46 example 9 Comparative 391 71 example 10 Comparative 350 70 example 11 Comparative 390 72 example 12 Comparative 411 70 X example 13 Comparative 413 71 X example 14

[0084] As summarized in the above tables, in the case of Comparative examples 1 and 2, it can be seen that the font is recognized with the naked eye by white coloring agent in the daytime, so that it is impossible to realize the hidden function.

[0085] Even when the cover is made of smoky resin, if the cover is thin as in Comparative example 3, the transmissivity is also increased and the light of the LED having the strong straight advancing property is not diffused well in the resin, resulting in the illumination in the form of spot. As a result, the uniformity of illumination is deteriorated.

[0086] On the contrary, as in the case of Comparative example 4, when the thickness of the cover is increased by a predetermined value or more, the transmissivity is decreased, and so luminance of the illumination is lowered.

[0087] In addition, as can be seen from Comparative examples 5 and 6, when the transmissivity of the cover is smaller than a reference value, luminance of the illumination is lowered. On the contrary, when the transmissivity of the cover is higher than the reference value, the luminance of the illumination is improved, but the uniformity of illumination is deteriorated.

[0088] Further, as in Comparative example 7, when turbidity of the cover is smaller than a certain value, the uniformity of illumination is deteriorated, and when brightness of the cover is higher than a certain value as in Comparative example 8, it is difficult to realize a hidden function to a level at which the font is recognized with the naked eye, and the transmissivity is somewhat decreased due to an addition of white coloring agent, so that the luminance of illumination is deteriorated.

[0089] Next, when a material of the electrode is FPCB, as in Comparative example 9, there is a problem that the luminance is insufficient and the uniformity is deteriorated even if the electrode is formed of smoky resin and has the optimum structure.

[0090] In addition, when a thickness of the electrode is greater than a predetermined value, as in Comparative example 10, when an evaluation of bending ability of the film on which ITO is deposited is conducted, surface resistance is generated due to fine cracks of ITO. Therefore, the touch performance is degraded.

[0091] In the case of Comparative example 11, the transmissivity of the electrode is lowered to a certain value, so that the transmittance of the light of the LED is deteriorated and the luminance of the illumination is reduced. In the case of Comparative example 12, the turbidity of the electrode is increased to a certain value or more, a decrease in the luminance of illumination is generated.

[0092] In addition, when yellowness of the electrode is high as in Comparative example 13, light characteristic such as absorption of light is changed when the LED illumination is transmitted, so that the illumination color is changed. When surface resistance of the electrode is higher than a certain value or more, touch performance is degraded due to a decrease in capacitance.

[0093] FIG. 17 schematically illustrates a touch-type button for a vehicle according to another exemplary embodiment of the present disclosure.

[0094] As shown in FIG. 17, in another embodiment of the present disclosure, optical characteristics can be further improved by adding a light diffusing film 40. The light diffusing film 40 attached to the ITO touch film 20 may have transmissivity of 85% or more and haze (turbidity) of 90% or more.

[0095] That is, when the transmissivity is smaller than the above range, the brightness of the LED illumination is deteriorated, and when the haze is smaller than the above range, the light uniformity is deteriorated due to lowered light diffusivity.

[0096] A conventional touch-type button has been configured to be operated in a manner in which the font of the button is appeared in white in the daytime and the lighting is turned on only at night. Consequently, when night illumination is too bright, glare and light blur occur, so that brightness of the night illumination has to be low.

[0097] However, according to the touch-type button for a vehicle of the present disclosure, a hidden function by which the font is not visible before a vehicle is started-up is realized, and the font is illuminated by the illumination at the moment of starting-up the vehicle. Therefore, it is possible to recognize the font, day and night, using the illumination, and to obtain high brightness performance.

[0098] In addition, since the ITO touch film employed as the transparent electrode is directly attached to the rear surface of the hidden cover, the illumination area can be widened through the high light transmittance, and by realizing the uniform illumination, size of the font can be variously made.

[0099] In addition, there is an advantage that since the conductor area is increased, the touch sensitivity is improved more than twice.

[0100] Although the present disclosure has been described with reference to the exemplary drawings, the present disclosure is not limited to the described embodiments, and it will be apparent to those skilled in the art that the present disclosure may be variously modified and changed without departing from the spirit and scope of the present disclosure. Accordingly, such modifications or changes are intended to fall within the scope the appended claims of the present disclosure, and the scope of the present disclosure should be construed on the basis of the appended claims.