KR101285524B1 - Input device - Google Patents

Abstract

assignment
An input that can effectively prevent internal reflection of light from the outside and, in addition, display light as circularly polarized light, which can prevent the display light from darkening or coloring when viewed by a user wearing sunglasses having a polarizing function. Provide a device.
Solution
As for the capacitive input panel 40, both the late board 41 and the electrical plate 42 which have a translucent electrode layer are comprised from (lambda) / 4 phase (s) difference film, and the insulating layer 43 is formed of the polarizing film. The external light 1 penetrates the input panel 40 to become circular polarized light 2. Even if the circularly polarized light 2 is reflected by the front surface 30a or the like of the display panel 30, the reflected light is blocked by the input panel 40. On the other hand, the display light 4 from the display panel 30 becomes the circularly polarized light 6 by transmitting the input panel 40. Therefore, even if the user equipped with the sunglasses etc. which have a polarizing function sees from any direction, the subject which the display light becomes dark can be eliminated.

Description

Input device {INPUT DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input device which is disposed in front of display panels such as an electroluminescent panel, a liquid crystal display panel, and can perform operation input by an input panel such as a capacitance detection type.

The operation part of various electronic devices, such as a portable device, is provided with the input device which has a translucent input panel on the surface of a display panel. The input panel includes, for example, a capacitance detection type, and includes transmissive electrodes that intersect with each other, and detects the capacitance formed between the electrode and the finger when the finger touches the panel surface, thereby specifying the contact position of the finger. It is.

In the said operation part, external light is reflected by the boundary part of each layer, and there exists a problem of reflected light superimposed on the display image of a display panel.

In the touch panel described in Patent Document 1 below, a capacitance-sensitive touch panel is provided on the surface of a liquid crystal display element, a phase difference plate and a polarizing plate of 1/4 wavelength are formed on the surface side of the touch panel, and the display of the touch panel is performed. The retardation plate of 1/4 wavelength is formed in the back surface side which faces a panel. Light entering from the outside is converted into linearly polarized light by the polarizing plate on the surface side, and passes through the retardation plate on the surface side to become circularly polarized light. When circularly polarized light is reflected inside the touch panel or on each surface of the display panel, the phase of the reflected light is shifted by [pi] / 2. When the reflected light passes back through the retardation plate on the surface side, the polarization direction becomes linearly polarized light orthogonal to the transmission axis of the polarizing plate, and the reflected light is blocked not to go out.

Moreover, the linearly polarized display light emitted from the liquid crystal display element transmits both the retardation plate on the back side and the retardation plate on the surface side, so that the polarization direction becomes linearly polarized light of the same phase coinciding with the direction of the transmission axis of the polarizing plate. Therefore, it becomes possible to pass this polarizing plate. As a result, the loss of display light is reduced.

In the transparent touch switch of the following patent document 2, a linear polarizing plate and (lambda) / 4 phase (s) difference plate are formed in the surface side of a touch switch, and (lambda) / 4 phase (s) difference plate is formed in the back surface side of a touch switch. Similar to the invention of Patent Document 1, this invention can block reflection of light incident from the outside, and the display light emitted from the liquid crystal display device is linearly polarized and sent out.

As for the touchscreen of following patent document 3, as a capacitance type which has a translucent electrode layer, (lambda) / 4 phase (s) difference plate is formed in the side which opposes a display panel, and the polarizing plate is formed in the side from which display light is emitted. Moreover, the structure which arrange | positions a touch panel through the air layer in front of a display panel is disclosed. When external light is reflected at the interface between the air layer and the surface panel, the reflected light is blocked by the λ / 4 retardation plate and the polarizing plate. On the other hand, the display light emitted from the display panel is transmitted through the λ / 4 retardation plate and the polarizing plate to be linearly polarized light.

Japanese Laid-Open Patent Publication No. 2008-262326 Republished patent publication of WO2006 / 126604 WO2006 / 028131 Patent Publication

In each of the above-mentioned patent documents, the lambda / 4 phase difference plate is formed on the side facing the display panel, and the polarizing plate is formed in front of it, so that the reflected light reflected in the panel or the reflected light reflected from the surface of the display panel is blocked. . On the other hand, since the display light emitted from the display panel finally passes through the polarizing plate, the display light is converted into linearly polarized display light and sent out to the front.

Therefore, when a person wearing sunglasses or the like having a polarizing function is seen, when the relative angles of the transmission axis of the polarizing plate formed on the touch panel and the transmission axis such as sunglasses cross, the display light becomes extremely dark or the screen is colored. There is a case.

In particular, when a portable device equipped with a display panel and a touch panel is used outdoors, the direction of the portable device is often changed. In this case, when the user wears sunglasses having a polarizing function, the display information of the display panel becomes very difficult to see depending on the attitude of the mobile device.

SUMMARY OF THE INVENTION The present invention solves the above-described problems, and the user can block the reflected light when the external light is reflected inside, and furthermore, the user wearing sunglasses or the like having a polarizing function such that the display light does not become linearly polarized light, It is an object of the present invention to provide an input device in which display contents are easy to see.

Moreover, an object of this invention is to provide the input device of the structure which reduces the number of layers and is easy to thin by using both (lambda) / 4 phase (s) difference function and polarization function for the layer which comprises an input panel.

The present invention provides an input device including a transmissive input panel and having a rear surface facing the display panel and a front surface from which display light is emitted.

The rear surface is provided in front of the display panel via an air layer, and has a polarization layer disposed between the rear surface and the front surface, between two lambda / 4 phase difference layers and two lambda / 4 phase difference layers. The light conversion layer is formed.

Since the input device of the present invention can have a structure in which an air layer is formed between the input panel and the display panel and the pressure sensitive adhesive layer is not interposed, there is no problem that air bubbles enter the pressure sensitive adhesive layer that bonds the input panel and the display panel. Do not. In addition, by arranging the light conversion layer in front of the air layer, it is possible to block the light reflected from the interface between the air layer and the display panel, and the state in which the display quality is deteriorated by the reflected light from the interface is less likely to occur. In addition, in the light conversion layer, since the emission side of the display light is a λ / 4 phase difference layer, the display light is converted into circularly polarized light rather than linearly polarized light and is emitted. Therefore, when the user wears sunglasses or the like having a polarization function, no matter how the direction of the input device is changed, problems such as dark display light and coloration are less likely to occur.

In the present invention, the input panel itself has two substrate sheets each having a translucent electrode layer as the light conversion layer, and a transmissive insulating layer positioned between the two substrate sheets, and the two substrate sheets. Is preferably the λ / 4 retardation layer, and the insulating layer is a polarizing layer.

As mentioned above, by using three layers which comprise a translucent input panel as a (lambda) / 4 phase (s) difference layer and a polarizing layer, the number of layers of an input device can be reduced and it becomes easy to realize thinning.

In the present invention, it is preferable that the input panel is a capacitance detection type that does not include an air layer.

In addition, in the present invention, the display panel emits display light of artificial light that is not linearly polarized light or circularly polarized light.

Alternatively, in the present invention, the display panel emits linearly polarized display light, and a λ / 4 phase difference layer is further formed between the display panel and the light conversion layer.

In the input device of the present invention, even when an air layer is formed between the display panel, the light conversion layer can block the reflected light from the interface between the air layer and the display panel, so that the display quality due to the reflected light can be easily prevented.

In addition, since the display light of the display panel is transmitted through circularly polarized light through the λ / 4 retardation layer, even if a user wearing sunglasses or the like having a polarizing function changes the direction of the display device, the display light is used. It is possible to prevent darkening or coloration.

Moreover, by making the layer which comprises an input panel into (lambda) / 4 phase (s) difference layer and a polarizing layer, the number of layers which comprise an input device can be reduced and it becomes easy to thin.

1 is an exploded perspective view of a portable device on which the input device of the embodiment of the present invention is mounted.
2 is a cross-sectional view showing an input device and a display panel according to the first embodiment of the present invention.
3 is a cross-sectional view illustrating an input device and a display panel according to a second embodiment of the present invention.
4 is an exploded perspective view illustrating an example of an input panel.

The portable device 10 shown in FIG. 1 is used as a mobile phone, a portable information processing device, a portable storage device, a portable game device, or the like.

The portable device 10 has a synthetic resin case 2. The case 2 has the recessed part 3 which opened upward, and the circuit board and display panel 30 which mounted the electronic circuit inside the recessed part 3 are accommodated. The opening part of the recessed part 3 is covered by the input device 20 of embodiment of this invention. The input device 20 has a display area 20a through which display light from the display panel 30 transmits, and a non-display area 20b through which light surrounding the display area 20a cannot transmit.

The display panel 30 shown in FIG. 2 is a self-luminous panel such as an electroluminescent panel. The display light emitted from the display panel 30 is artificial light in a state close to natural light, not linearly polarized light, circularly polarized light, or elliptically polarized light.

The display panel 30 has a front surface 30a through which display light is emitted. The spacer 31 is fixed to the front surface 30a, and the input device 20 is fixed in front of the spacer 31. In the input device 20, the surface facing the display panel 30 is the rear surface 20c, and the surface on which the display light is sent is the front surface 20d. The spacer 31 is a frame shape surrounding the display area 20a of the input device 20. In the display area 20a, the spacer 31 has a front surface 30a of the display panel 30 and a rear surface of the input device 20 ( A thin air layer 32 is formed between 20c). The said spacer 31 is a double-sided adhesive tape, an adhesive bond layer, or an adhesive layer.

As shown in FIG. 2, the input device 20 has a light transmissive input panel 40. Translucent in this specification means the state which can permeate | transmit light, such as transparent or translucent, and means that the total light transmittance is 50% or more, Preferably it is 80% or more.

As shown in FIG. 4, the input panel 40 has a translucent late plate 41 and an electric plate 42 and an insulating layer 43 sandwiched between the late plate 41 and the electric plate 42. . The first electrode layer 44 is formed on the front surface 41a of the late plate 41, and the second electrode layer 45 is formed on the front surface 42a of the electrical plate 42. The first electrode layer 44 and the second electrode layer 45 are each formed of a plurality of conductive layers formed in parallel with each other, and the first electrode layer 44 and the second electrode layer 45 include the insulating layer 43 and It is formed in the direction orthogonal to each other across the electric plate 42.

The latter plate 41 and the electric plate 42 are both formed of a lambda / 4 phase difference film. The first electrode layer 44 and the second electrode layer 45 are formed of a light-transmissive conductive material such as ITO. The ITO film is laminated | stacked previously on the whole surface of the front surface 41a of the late board 41, and the 1st electrode layer 44 is formed by etching this ITO film | membrane. Similarly, the ITO film is laminated | stacked previously on the whole surface of the front surface 42a of the electrical plate 42, and the 2nd electrode layer 45 is formed by etching this ITO film | membrane.

In addition, the 1st electrode layer 44 may be formed in the back surface 41b of the late board 41, and the 2nd electrode layer 45 may be formed in the back surface 42b of the electrical plate 42. As shown in FIG.

The insulating layer 43 is formed of the polarizing film which is a polarizing layer. The insulating layer 43 is sandwiched between the late plate 41 and the electrical plate 42, and the late plate 41 and the insulating layer 43 are bonded together via a light-transmissive pressure-sensitive adhesive layer such as acrylic. The electrical plate 42 and the insulating layer 43 are bonded together via a light-transmissive pressure-sensitive adhesive layer such as acrylic.

The input panel 40 is a capacitance detection type. Voltages are sequentially applied to the plurality of first electrode layers 44, and voltages are sequentially applied to the plurality of second electrode layers 45 at different timings. When a human finger, which is a conductor almost at ground potential, approaches an electrode layer, a capacitance is formed between the electrode layer and the finger. By detecting this change in capacitance, the position where the finger approaches can be detected.

In the input panel 40, both the late plate 41 and the electric plate 42 are formed of a lambda / 4 phase difference film, the optical axis of the lambda / 4 phase difference film constituting the late plate 41, and the electric plate ( The optical axis of the (lambda) / 4 phase (s) difference film which comprises 42) intersects at substantially 90 degree | times. The insulating layer 43 is formed of the polarizing film, and the transmission axis of this polarizing film and the optical axis of each said (lambda) / 4 phase (s) difference film intersect at the angle of almost 45 degree | times. Therefore, the input panel 40 can itself function as a light conversion layer.

As shown in FIG. 2, the transparent cover layer 21 is adhered to the entire surface of the front of the input panel 40 via a transparent adhesive layer such as acrylic. The cover layer 21 is formed of light-transmissive resin, such as glass, PMMA (methyl methacrylate resin), PC (polycarbonate), and COP (cyclic olefin copolymer). A decorative layer is formed on the back or front surface of the cover layer 21, and is colored so that light may not permeate | transmit in the non-display area 20b, as shown in FIG.

As shown in FIG. 2, the antireflection film 22 is formed on the rear surface of the input panel 40. The surface of the antireflection film 22 is the rear surface 20c of the input device 20.

In the portable device 10 shown in FIG. 1, a user in which display light displayed on the display panel 30 is transmitted through the display area 20a of the input device 20 and forwarded to the display area 20a is displayed. When the finger is placed on the front surface 20d of the input device 20 while viewing the display image projected on the screen, the contact position of the finger is detected by the input panel 40. The control unit can grasp the contents of the display image and the operation contents to be input by the user from the contact position of the finger.

On the right side of FIG. 2, the transmission path of the external light 1 entering the display area 20a of the input device 20 from the outside is indicated by (A), and the transmission of the display light 4 emitted from the display panel 30 is shown. The path is shown by (B).

As shown by (A) in FIG. 2, the external light 1 which is natural light which permeate | transmitted the cover layer 21 permeate | transmits the input panel 40 which is a light conversion layer. When the external light 1 passes through the insulating layer 43 of the input panel 40, the late plate 41 is converted into linearly polarized light by the insulating layer 43, which is a polarizing layer, and formed of a lambda / 4 phase difference film. By transmission, circular polarization 2 is obtained. When the circularly polarized light 2 is reflected at the interface between the air layer 32 and the front surface 30a of the display panel 30, the circularly polarized light 2 becomes the circularly polarized light 3 in the opposite direction and returns. Although this circularly polarized light 3 becomes a linearly polarized light by transmitting the late board 41 formed from (lambda) / 4 phase (s) retardation film again, this optical axis of linearly polarized light has the transmission axis of the polarizing film which comprises the insulating layer 43, and Since it is different by 90 degrees, the reflected light is absorbed by the insulating layer 43 and is blocked without returning to the outside.

A part of the circularly polarized light 2 transmitted through the input panel 40 from the external light 1 enters the inside of the display panel 30 and is reflected by the electrode layer formed on the display panel 30. Since the reflected light also returns to the circularly polarized light 3 in the opposite direction, it is blocked by the insulating layer 43 of the input panel 40 which is a light conversion layer.

As shown by (B) in FIG. 2, the display light 4 emitted from the self-luminous display panel 30, such as an electroluminescent panel, is artificial light near natural light. The display light 4 is prevented from being reflected by the antireflection layer 22, and most of the display light 4 is provided to the input panel 40. The circularly polarized light 5 is transmitted by transmitting the polarizing film that is the insulating layer 43 of the input panel 40 to the linearly polarized light 5 and transmitting the electric plate 42 formed of the lambda / 4 phase difference film. 6) becomes That is, the display light from the display panel 30 becomes the circularly polarized light 6 and passes through the cover layer 21 and comes out forward.

Therefore, even if the user wears sunglasses or the like having polarization function, since the display light is circularly polarized light, the display light passing through the sunglasses can be prevented from being dark or colored even when the mobile device 10 is used in any direction. have.

As shown in FIG. 4, by the input panel 40 in which the late plate 41, the electric plate 42, and the insulating layer 43 are stacked, two λ / 4 retardation layers and one polarizing layer are combined. Since the light conversion layer is configured, there is no need to separately form the input panel and the light conversion layer, so that the number of layers of the input device 20 can be reduced to be thin.

In the embodiment shown in FIG. 2, when the input device 20 formed by laminating each layer is provided at the front of the display panel 30, the spacer 31 is formed instead of the entire surface adhesion to interpose the air layer 32. have. Then, the reflected light from the front surface 30a, which is the interface between the air layer 32 and the display panel 30, can be blocked by the input panel 40, which is a light conversion layer, to solve the problem that the air layer 32 interposes with. It is resolved. Therefore, it is not necessary to adhere the display panel 30 and the input device 20 to the whole surface via the adhesive layer, and the problem that the defective article increases by air bubbles intervening in an adhesive layer can be eliminated.

3 shows a portable device 110 of a second embodiment of the present invention.

The display panel 130 used for the portable device 110 shown in FIG. 3 includes a liquid crystal display panel. The input device 20 having the same structure as that of FIG. 2 is fixed to the front side of the display panel 130 via the spacer 31. Therefore, in the display area 20a, the air layer 32 is formed between the display panel 130 and the input device 20.

The display panel 130 has a backlight portion that provides light from an LED or a lamp from behind the liquid crystal display panel.

The liquid crystal display panel has a transparent electrode facing each other with a liquid crystal material layer interposed therebetween, and has an alignment layer and a polarizing layer facing each other with a liquid crystal material layer interposed therebetween. Therefore, the display light provided from the backlight unit and transmitted through the liquid crystal display panel is linearly polarized light. Therefore, 3rd (lambda) / 4 phase (s) difference film 131 is formed in the whole surface which is the emission side of the display light of the display panel 130. FIG. (Lambda) / 4 phase (s) difference film and 3rd (lambda) / 4 phase (s) difference film 131 which comprise the late board 41 of the input panel 40 are arrange | positioned so that an optical axis may orthogonally cross. Moreover, the polarizing film which comprises the polarizing layer formed in the side which transmits the display light of a liquid crystal display panel, and the insulating layer 43 of the input panel 40 mutually match the direction of the transmission axis of light.

In FIG. 3, (A) shows the path of the light when the external light 1 is incident, and (B) shows the path of the display light 7 sent out from the display panel 130. In FIG.

As shown in FIG. 3 (A), when the external light 1 is incident, the reflected light from the front surface 131a of the third λ / 4 retardation film 131 or the reflected light from the electrode layer of the liquid crystal display panel, It is blocked in the light conversion layer composed of the input panel 40. This is exactly the same as the embodiment of FIG. 2.

As shown in FIG. 3B, the light emitted from the backlight in the display panel 130 passes through the liquid crystal display panel. However, since the polarization layer is formed at the light exit portion of the liquid crystal display panel, the linearly polarized light It is sent out as the display light 7. The display light 7 of linearly polarized light is circularly polarized light 8 by passing through the third lambda / 4 phase difference film 131. Moreover, it returns to linearly polarized light 9 through the (lambda) / 4 phase (s) difference film which comprises the late board 41 of the input panel 40. FIG. Since the direction of a transmission axis is the same in the polarizing film which comprises the polarizing layer of the sending side of a liquid crystal display panel, and the insulating layer 43 of the input panel 40, the linearly polarized light 9 is made by the insulating layer 43 It does not block | block, but permeate | transmits the (lambda) / 4 phase (s) difference film which comprises the electrical plate 42 of the input panel 40. FIG. And it transmits the electric plate 42, it becomes circularly polarized light 10, and permeate | transmits the cover layer 21. FIG.

As described above, since the display light is also transmitted as circularly polarized light in the portable device 110 shown in FIG. 3, even if a user wearing sunglasses having a polarization function frequently changes the orientation of the portable device 110, It is possible to prevent the display light from darkening or coloring.

2: Case
10: Mobile devices
20: input device
21: cover layer
22: antireflection layer
30: display panel
31: spacer
32: air layer
40: input panel (light conversion layer)
41: late version (λ / 4 retardation film)
42: Electroplate (λ / 4 retardation film)
43: insulating layer (polarizing film)
44: first electrode layer
45: second electrode layer
110: mobile device
130: display panel
131: third lambda / 4 phase difference film

Claims (17)

An input device comprising a transmissive input panel and having a rear surface facing the display panel and a front surface from which display light is emitted,
The rear surface is provided in front of the display panel via an air layer, and has a polarization layer disposed between the rear surface and the front surface, between two lambda / 4 phase difference layers and two lambda / 4 phase difference layers. An input device, characterized in that the light conversion layer is formed. The method of claim 1,
An input device in which the optical axes of the two lambda / 4 phase difference layers form an angle of 90 degrees to each other, and the transmission axis of the polarization layer and the optical axis of each of the lambda / 4 phase difference layers form an angle of 45 degrees. 3. The method according to claim 1 or 2,
The input panel itself has, as the light conversion layer, two base sheets having a transmissive electrode layer and a translucent insulating layer positioned between the two base sheets, wherein the two base sheets have the? / 4 is a phase difference layer, and the said insulating layer is a polarizing layer. The method of claim 3, wherein
The input panel is a capacitive sensing input device that does not include an air layer. The method of claim 3, wherein
And an anti-reflection layer formed on a rear surface of the input panel. 3. The method according to claim 1 or 2,
The display panel is an input device that emits display light of artificial light, not linearly and circularly polarized light. The method of claim 3, wherein
The display panel is an input device that emits display light of artificial light, not linearly and circularly polarized light. The method according to claim 6,
The display panel is an electroluminescent panel. The method of claim 7, wherein
The display panel is an electroluminescent panel. 3. The method according to claim 1 or 2,
The display panel emits linearly polarized display light, and a third λ / 4 phase difference layer is further formed between the display panel and the light conversion layer. The method of claim 3, wherein
The display panel emits linearly polarized display light, and a third λ / 4 phase difference layer is further formed between the display panel and the light conversion layer. 11. The method of claim 10,
And the display panel is a liquid crystal display panel. The method of claim 11,
And the display panel is a liquid crystal display panel. 11. The method of claim 10,
An input device in which the optical axis of the [lambda] / 4 retardation layer formed behind the two [lambda] / 4 retardation layers and the third [lambda] / 4 retardation layer are perpendicular to each other. The method of claim 11,
An input device in which the optical axis of the [lambda] / 4 retardation layer formed behind the two [lambda] / 4 retardation layers and the third [lambda] / 4 retardation layer are perpendicular to each other. 13. The method of claim 12,
An input device in which the optical axis of the [lambda] / 4 retardation layer formed behind the two [lambda] / 4 retardation layers and the third [lambda] / 4 retardation layer are perpendicular to each other. The method of claim 13,
An input device in which the optical axis of the [lambda] / 4 retardation layer formed behind the two [lambda] / 4 retardation layers and the third [lambda] / 4 retardation layer are perpendicular to each other.

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