TWI412780B - Light transmissive film and fabrication method of light transmissive film - Google Patents

Abstract

A fabrication method of a light transmissive film including the following steps is provided. First, a film is provided. The film includes a plurality of nano-units and has a reference direction. Next, an energy beam is used to form a plurality of first stripes parallel to each other on the film. The first stripes are not parallel to the reference direction. A light transmissive film is also provided.

Description

Light-transmissive film manufacturing method and light-transmissive film

The present invention relates to a film and a method of manufacturing the same, and more particularly to a light transmissive film and a method of manufacturing the same.

With the development of display technology and multimedia technology, the traditional button interface or mouse control interface can not meet the needs of users. Due to the popularity of portable electronic devices, manufacturers have been pursuing an operation interface that is easier, more intuitive, and less space-consuming, and that touch panels are one of the components that can achieve these goals.

The conventional touch panel is mainly divided into a resistive touch panel and a capacitive touch panel. The resistive touch panel uses two indium tin oxide (ITO) films. When the user presses the resistive touch panel with a finger, the two indium tin oxide films are electrically connected to each other, and the processing unit can calculate the position of the finger pressing.

The capacitive touch panel divides the indium tin oxide layer into a plurality of patterns. When the user touches the capacitive touch panel with a finger, the capacitance value between the patterns changes, and the processing unit can calculate Press the position of the contact.

However, these patterns on the capacitive touch panel are more likely to cause unevenness of the picture. Further, the indium tin oxide film is more likely to be cracked or deteriorated when subjected to excessive bending or excessive bending. Therefore, when an indium tin oxide film is applied to a flexible panel, it is easy to cause a decrease in the reliability of the flexible panel.

The invention provides a method for manufacturing a light transmissive film, wherein the stripes formed are less easily observed by the human eye, and the stripes are less likely to be generated with other periodic structures. Obvious moire.

The present invention provides a light transmissive film in which the streaks on the surface are less easily observed by the human eye, and the streaks are less likely to cause significant overlapping with other periodic structures.

One embodiment of the present invention provides a method of manufacturing a light transmissive film comprising the following steps. First, a film is provided in which the film comprises a plurality of nano-units and has a reference direction. Next, an energy beam is used to form a plurality of first stripes parallel to each other on the film, wherein the first stripes are not perpendicular and are not parallel to the reference direction.

Another embodiment of the present invention provides a light transmissive film produced by the above method for producing a light transmissive film.

Yet another embodiment of the present invention provides a light transmissive film comprising a plurality of nanocells and a plurality of first strips that are parallel to each other. These nano units form a film. These first stripes are located on the surface of the film, wherein the first stripes are not perpendicular and are not parallel to a reference direction of the film.

Based on the above, in the embodiment of the present invention, since the first stripe is not perpendicular and is not parallel to the reference direction, the first stripe formed by the method for manufacturing the transparent film and the first stripe of the transparent film are less likely to be Other periodic structures produce significant moiré.

The above described features and advantages of the present invention will be more apparent from the following description.

1A to 1D are schematic flow charts showing a method of manufacturing a light-transmissive film according to an embodiment of the present invention. The method for producing a light-transmitting film of this embodiment includes the following steps. First, referring to FIG. 1A, a film 100 is provided in which the film 100 includes a plurality of nano cells and has a reference direction D1. In this embodiment, the nano units are, for example, a plurality of carbon nano-tubes, and The film 100 is, for example, a carbon nanotube film. However, in other embodiments, the nanocells may also be nanometer-sized conductive molecules or conductive grains, such as nano-metal grains. In the present embodiment, the film 100 is an anisotropic conductive film, and the main conductive direction of the conductive anisotropic conductive film (ie, the direction with the smallest impedance) is substantially parallel to the reference. Direction D1. Microscopically, these carbon nanotubes extend approximately along the reference direction D1.

In the present embodiment, the step of providing the film 100 includes the following steps. First, a carbon nanotube layer 60 is formed on a substrate 50. The substrate 50 is, for example, a tantalum substrate, a quartz substrate, or other suitable substrate. The method of forming the carbon nanotube layer 60 is, for example, by chemical vapor deposition (CVD) or other suitable method. Next, the carbon nanotube film is pulled out from one side of the carbon nanotube layer 60 in a stretching direction (in this embodiment, the reference direction D1). Specifically, for example, one side of the carbon nanotube film is sandwiched by a pull film holder arm 70 and pulled out from the side of the substrate 50. When the carbon nanotube film is pulled out, the carbon nanotubes therein extend substantially toward the reference direction D1. In the present embodiment, the reference direction D1 is, for example, the stretching direction of the film 100. However, the reference direction D1 may also be substantially parallel to one side M of the film 100.

Next, referring to FIG. 1B, an energy beam 82 is irradiated onto the film 100 to form a plurality of first stripes 210 parallel to each other on the film 100, wherein the first stripes 210 are not perpendicular and are not parallel to the reference direction. D1. The first stripe 210 has a difference from its adjacent structure that is not illuminated by the energy beam 82, which may be a physical, structural or optical difference. For example, such a difference is, for example, a difference in surface texture, a difference in nano cell density, a difference in surface roughness, and a difference in thickness (ie, the first stripe 210 is a concave line), The difference in the structure of the rice unit (such as the difference between double-walled carbon nanotubes and single-walled carbon nanotubes), the phase difference of the nano-units The difference in intensity between the opposite and reflected light (such as the contrast between the first stripe 210 and its neighboring structure due to the reflected light), and the difference in the intensity of the transmitted light (eg, the difference between the first stripe 210 and its adjacent structure due to light transmittance) The resulting contrast between light and dark) or the intensity of the diffracted light. In the present embodiment, the extending direction L1 of the first stripe 210 is inclined by an angle θ with respect to a reference direction R1 perpendicular to the reference direction D1 on the surface of the film 100, where θ is greater than 0 and less than 90 degrees. However, in other embodiments, θ may also be less than 0 and greater than -90 degrees, that is, the direction of inclination of the extension direction L1 relative to the reference direction R1 is opposite to the direction indicated by the arrow next to the θ symbol in FIG. 1B. The energy beam 82 is, for example, a laser beam emitted by a laser source 80, and its wavelength may fall in the visible light band, the ultraviolet light band, the infrared light band, or other electromagnetic wave bands, and the invention is not limited thereto. However, in other embodiments, the energy beam 82 can also be a beam of kinetic energy particles, such as an electron beam, a proton beam, a helium nucleus beam, or other suitable particle beam.

In the present embodiment, the method of forming the first strips 210 using the energy beam 82 includes scanning the energy beam 82 along a scanning direction S1 parallel to the reference direction D1 (in the present embodiment, the scanning direction S1 and the reference direction) D1 points in the opposite direction) to form these first stripes 210 in order. In the present embodiment, the first strips 210 are periodically arranged, for example, at equal intervals or in other forms of periodic arrangement. For example, the width W of the first strips 210 is, for example, about 110 micrometers, and the pitch P of the first strips 210 is, for example, in the range of 200 micrometers to 350 micrometers, but the present invention does not Limited.

Thereafter, referring to FIG. 1C, the manufacturing method of the light transmissive film of the present embodiment may further include the energy beam 82 along the scanning direction S1, S2 parallel to the reference direction D1 (in the present embodiment, the scanning direction S2 and the reference direction) D1 is in the same direction) repeatedly scanning to the positions of the first strips 210 to reinforce the first strips 210 The difference from the structure adjacent thereto that is not irradiated by the energy beam 82 is, for example, deepening the depth of the depression of the first stripe 210, enhancing the difference in surface texture, enhancing the difference in density of the nanocells, and enhancing the difference in surface roughness. Sexuality, strengthening the structure of nano-units, enhancing the phase difference of nano-units, enhancing the intensity difference of reflected light, enhancing the intensity difference of transmitted light or enhancing the intensity difference of diffracted light. In the present embodiment, for example, it is alternately scanned back and forth a plurality of times along the scanning directions S1 and S2 to increase the depth of the recess of the first stripe 210. However, in other embodiments, when the energy beam 82 is alternately scanned back and forth along the scanning directions S1 and S2, it is also possible not to repeatedly scan the positions of the first stripes 210 that have been formed before, but instead shift the original Position a distance.

In the present embodiment, the first stripe 210 increases the transmittance of the film 100 to form the light transmissive film 200 as shown in FIG. 1D. Specifically, the light transmissive film 200 of the present embodiment includes a plurality of the above-described nano cells and the first stripes 210. These nano cells form the film 100, and the first stripes 210 are located on the surface of the film 100.

In the present embodiment, since the first stripe 210 is not perpendicular and is not parallel to the reference direction D1, the extending direction L1 (for example, the adjustment angle θ), the width W, and the pitch P of the first stripe 210 are appropriately adjusted (eg, As shown in FIG. 1B, it is possible to prevent the first stripe 210 from forming a moiré with other periodic structures, such as a pixel array of a display panel.

2A and 2B are schematic flow charts showing a method of manufacturing a light-transmissive film according to another embodiment of the present invention. The manufacturing method of the light transmissive film of this embodiment is similar to the manufacturing method of the light transmissive film shown in FIGS. 1A to 1D, and the main differences between the two are as follows. Referring to FIG. 2A, the method for manufacturing a light transmissive film of the present embodiment further includes forming, by using the energy beam 82, a plurality of second strips 220 parallel to each other on the surface of the film 100, wherein each of the second strips 220 is not parallel to each A first stripe 210. The characteristics of the second stripe 220 are similar to those of the first stripe 210 and will not be repeated here. Further, the second stripes 220 may be arranged in a periodic manner. In the present embodiment, the extending direction L2 of the second stripe 220 is inclined by an angle φ with respect to the reference direction R1, for example, φ is less than 0 and greater than -90 degrees. However, in other embodiments, one of φ and θ may also be equal to zero. In this embodiment, the width and pitch of the second stripe 220 may be approximately the same as the width and pitch of the first stripe 210. Moreover, in the present embodiment, the energy beam 82 can be scanned back and forth a plurality of times along the scanning directions S1 and S2 to enhance the difference between the second strip 220 and its adjacent structure.

These first stripes 210 and second stripes 220 increase the transmittance of the film 100 to form the light transmissive film 200'. In the present embodiment, the first stripe 210 and the second stripe 220, which are not parallel to each other, mutually destroy each other's periodicity, so that the first stripe 210 and the second stripe 220 are not easily visually observed by the user. Therefore, when the light-transmissive film 200' of the present embodiment is used as a conductive film of a touch panel, the quality, brightness uniformity, and color uniformity of the display image can be improved. In addition, the light transmissive film 200' of the present embodiment can also be attached to a window or an insulating paper to provide a touch function to the window. Furthermore, the light transmissive film 200' of the present embodiment can also be used as a conductive film of a flexible panel such as a flexible display panel or a flexible touch display panel, since the carbon nanotube film has better The flexible characteristics are not easily deteriorated due to excessive bending or excessive bending, so that the reliability of the flexible panel can be improved.

In addition, since the first stripe 210 and the second stripe 220 which are not parallel to each other mutually destroy each other's periodicity, the first stripe 210 and the second stripe 220 are less likely to be associated with other periodic structures (for example, the panel of the display panel). The array) forms a moiré. In this way, when the light transmissive film of the embodiment is used as the conductive film of the touch display, the display quality and the uniformity of the image can be improved.

3A and 3B are schematic flow charts showing a method of manufacturing a light-transmissive film according to still another embodiment of the present invention. The manufacturing method of the light transmissive film of this embodiment is similar to the manufacturing method of the light transmissive film shown in FIGS. 2A and 2B, and the difference between the two is as follows. Referring to FIG. 3A, the method for fabricating the light transmissive film of the present embodiment further includes forming, by the energy beam 82, a plurality of third strips 230 parallel to each other on the surface of the film 100, wherein each of the third strips 230 is not parallel to Each of the first stripes 210 is not parallel to each of the second stripes 220. The characteristics of the third stripe 230 are similar to those of the first stripe 210 and the second stripe 220, and will not be repeated here. In addition, the third stripes 230 may be arranged in a periodic manner. In this embodiment, the extending direction L3 of each of the third strips 230 is substantially parallel to the reference direction R1, that is, inclined by 0 degrees with respect to the reference direction R1, but the invention is not limited thereto. In this embodiment, the energy beam 82 can be alternately scanned back and forth along the scanning directions S2 and S2 to enhance the difference between the third strip 230 and its adjacent structure.

The first stripe 210, the second stripe 220 and the third stripe 230 can increase the transmittance of the film 100 to form the light transmissive film 200". Since the light transmissive film 200" of the embodiment has three sets of different extending directions The stripe 210, the second stripe 220, and the third stripe 230 are thus more damaging to the periodicity of the stripe. As a result, the first stripe 210, the second stripe 220, and the third stripe 230 on the light transmissive film 200" are more difficult to be observed by the naked eye, and are more difficult to form a moiré with other periodic structures.

4 is a schematic view showing a method of manufacturing a light-transmissive film according to still another embodiment of the present invention. Referring to FIG. 4, the manufacturing method of the light transmissive film of the present embodiment is similar to the manufacturing method of the light transmissive film of FIGS. 1A to 1D, and the difference between the two is as follows. In the present embodiment, before the first strip 210 is formed by the energy beam 82, the film 100 to be pulled out is further included on a carrier 90. In this embodiment, the carrier 90 is, for example, a gel. The film 100 is placed on the carrier 90 Thereafter, the formation of the first stripe 210 is started. At this time, the reference direction D1 is substantially parallel to the side M of the film 100. The manufacturing method of the light transmissive film of the present embodiment and the light transmissive film produced by the same have similar advantages and effects as those of the above embodiment, and will not be repeated here.

Fig. 5 is a schematic view showing the stripe at a distance A from the naked eye and the stripe. Referring to FIG. 5, when the solid angle θ1 of the stripe is smaller than the solid angle corresponding to the contrast sensitivity, the naked eye cannot distinguish the stripe. On the contrary, when the solid angle θ1 opened by the human eye is larger than the solid angle corresponding to the contrast sensitivity, the naked eye can easily observe the stripe. On the other hand, under a certain contrast condition, the minimum solid angle corresponding to the human eye can be compared with the observed solid angle θ1. If the solid angle θ1 obtained by observation is small, the naked eye cannot distinguish the doublet; , you can observe the pattern. Among them, the formula for contrast and contrast sensitivity (CSF) is as follows: Contrast sensitivity = 1 / contrast; where Δ l is the difference between the maximum brightness and the minimum brightness of the stripe, l _ave is the average brightness of the stripe, l _max is the maximum brightness of the stripe, and l _min is the minimum brightness of the stripe.

Thus, the embodiment of FIGS. 1A-1D and 4 can reduce the degree of moiré by controlling the contrast, contrast sensitivity, and the width and pitch of the first strip 210. In addition, the embodiments of FIGS. 2A, 2B, 3A, and 3B use a plurality of sets of stripes of different extending directions to break the periodicity between each other, so that even when the human eye observes a stripe of a single extending direction, the stripe is opened. When the solid angle θ1 is larger than the solid angle corresponding to the contrast sensitivity, or the minimum solid angle corresponding to the human eye under a certain contrast condition is smaller than the observed At the solid angle θ1, it is also less likely to be observed by the naked eye.

Fig. 6 is a diagram showing the distribution of the degree of rubbing caused by the two-period structure at different angles and periods. Referring to FIG. 6, the horizontal axis represents the angle of the two-period structure, and the vertical axis represents the period ratio of the two-period structure. The number on the curve in the figure represents the degree of the moiré, and the larger the number, the greater the degree of moiré. The relationship between the stripe of the above embodiment of the present invention and other periodic structures (for example, the pixel array of the display panel) can be designed in a region where the number on the curve is small, so that the quality of the display screen and the uniformity of the screen can be improved.

7A to 7G show optical micrographs of stripes, and the actual dimensions are known from the scales in the figures. Referring to FIG. 7A, which is an enlarged view of the film when the stripe is perpendicular to the reference direction D1 of FIG. 1A, it can be seen that the stripe is quite conspicuous. Fig. 7B is an enlarged view of the light transmissive film 200 produced in the embodiment of Figs. 1A to 1D, wherein θ = 45 degrees, and it can be seen that the streaks are slightly inconspicuous. Fig. 7C is an enlarged view of the light transmissive film 200' produced in the embodiment of Figs. 2A to 2B, where θ = 3 degrees and φ = -3 degrees. Fig. 7D is an enlarged view of the light transmissive film 200' produced in the embodiment of Figs. 2A to 2B, where θ = 5 degrees and φ = -5 degrees. Figure 7E is an enlarged view of the light-transmissive film 200' produced in the embodiment of Figures 2A to 2B, wherein θ = 8 degrees and φ = -8 degrees, as can be seen from the figure, even after observation through an optical microscope, the stripes It is quite unobvious. 7F is an enlarged view of the light transmissive film 200' produced in the embodiment of FIGS. 2A to 2B, wherein θ=10 degrees and φ=-10 degrees, as can be seen from the figure, even after observation by an optical microscope, the stripes It is quite unobvious. 7G is an enlarged view of the light transmissive film 200" made by the embodiment of FIGS. 3A to 3B, wherein θ=45 degrees, φ=−45 degrees, and the extending direction L3 is inclined by 0 degrees with respect to the reference direction R1. It can be seen that the streaks are extremely inconspicuous even when observed by an optical microscope.

It should be noted that the present invention is not limited to the manufacturing method of the transparent film. The stripe or the light-transmissive film produced has streaks of three or less groups having different extending directions. In other embodiments, it is also possible to form or adopt four or more stripes having different extending directions.

In summary, in the embodiment of the present invention, since the first stripe is not perpendicular and is not parallel to the reference direction, the first stripe formed by the method for manufacturing the transparent film and the first stripe of the transparent film have It is not easy to produce obvious folds with other periodic structures. In addition, in the embodiment of the present invention, since two or more stripes having different extending directions are formed and used to mutually break the periodicity of each other, the stripe and the light-transmissive film formed by the method for manufacturing the transparent film have The stripes are less easily recognized by the naked eye.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

50‧‧‧Substrate

60‧‧‧Nano carbon tube layer

70‧‧‧ Pull film clamp arm

80‧‧‧Laser light source

82‧‧‧ energy beam

90‧‧‧carrier

100‧‧‧film

200, 200', 200" ‧ ‧ light film

210‧‧‧First stripe

220‧‧‧Second stripes

230‧‧‧ third stripe

A‧‧‧ distance

D1, R1‧‧‧ reference direction

L1, L2, L3‧‧‧ extension direction

M‧‧‧ side

P‧‧‧ pitch

S1, S2‧‧‧ scan direction

W‧‧‧Width

θ, φ‧‧‧ angle

Θ1‧‧‧ solid angle

1A to 1D are schematic flow charts showing a method of manufacturing a light-transmissive film according to an embodiment of the present invention.

2A and 2B are schematic flow charts showing a method of manufacturing a light-transmissive film according to another embodiment of the present invention.

3A and 3B are schematic flow charts showing a method of manufacturing a light-transmissive film according to still another embodiment of the present invention.

4 is a schematic view showing a method of manufacturing a light-transmissive film according to still another embodiment of the present invention.

Fig. 5 is a schematic view of the stripes observed by the naked eye.

Fig. 6 is a diagram showing the distribution of the degree of rubbing caused by the two-period structure at different angles and periods.

7A to 7G show optical micrographs of stripes.

50‧‧‧Substrate

60‧‧‧Nano carbon tube layer

70‧‧‧ Pull film clamp arm

80‧‧‧Laser light source

82‧‧‧ energy beam

100‧‧‧film

210‧‧‧First stripe

D1, R1‧‧‧ reference direction

L1‧‧‧ extending direction

P‧‧‧ pitch

S1‧‧‧ scan direction

W‧‧‧Width

Θ‧‧‧ angle

Claims (18)

A method of manufacturing a light transmissive film, comprising: providing a film, wherein the film comprises a plurality of nano cells and having a reference direction; and forming a plurality of first stripes parallel to each other on the film by using an energy beam And wherein the first stripes are not perpendicular and are not parallel to the reference direction; wherein the step of providing the film comprises stretching the film along a stretching direction, and the reference direction is the stretching direction. The method for manufacturing a light-transmissive film according to claim 1, wherein the film is an anisotropic conductive film, and the main conductive direction of the anisotropic conductive film is substantially parallel to the Reference direction. The method for producing a light-transmitting film according to claim 2, wherein the conductive film having an anisotropy of impedance is a carbon nanotube film. The method for producing a light-transmissive film according to claim 3, wherein the step of providing the film comprises: forming a carbon nanotube layer on a substrate; and the carbon nanotubes along the stretching direction The carbon nanotube film is pulled out on one side of the layer. The method for producing a light-transmissive film according to claim 4, wherein the step of providing the film further comprises placing the drawn carbon nanotube film on a carrier. The method of producing a light-transmissive film according to claim 1, wherein the reference direction is substantially parallel to one side of the film. The method of manufacturing a light-transmissive film according to claim 1, wherein the energy beam is a laser beam or a particle beam. The method for producing a light-transmissive film according to claim 1, The method of forming the first fringes using the energy beam includes scanning the energy beam in a direction parallel to the reference direction to sequentially form the first fringes. The method for manufacturing a light-transmissive film according to claim 8, further comprising repeatedly scanning the energy beam in a direction parallel to the reference direction to the positions of the first stripes to enhance the first The difference between stripes and their adjacent structures. The method for manufacturing a light-transmissive film according to claim 1, further comprising forming, by the energy beam, a plurality of second stripes parallel to each other on the film, wherein each of the second stripes is not parallel to each One of the first stripes. The method for producing a light-transmissive film according to claim 1, wherein the first stripes are periodically arranged. A light-transmitting film produced by the method for producing a light-transmitting film according to the first, second, fourth, fifth, sixth or tenth aspect of the patent application. A light transmissive film comprising: a plurality of nano-units forming a film; and a plurality of first stripes parallel to each other on the surface of the film, wherein the first stripes are not perpendicular and are not parallel to one of the films a reference direction; wherein the reference direction is a direction of stretching of the film at the time of manufacture. The light transmissive film of claim 13, wherein the reference direction is substantially parallel to one side of the film. The light transmissive film of claim 13, wherein the film is an anisotropic conductive film, and the main conductive direction of the anisotropic conductive film is substantially parallel to the reference direction. The method for producing a light-transmitting film according to claim 15, wherein the conductive film having an anisotropy of impedance is a carbon nanotube film. The light transmissive film of claim 13, further comprising a plurality of second stripes parallel to each other on the surface of the film, wherein each of the second stripes is not parallel to each of the first stripes. The light transmissive film of claim 13, wherein the first stripes are periodically arranged.