CN101334497B

CN101334497B - Polarized light splitting device and manufacture method thereof and equipment and comprise its display

Info

Publication number: CN101334497B
Application number: CN200710127524.7A
Authority: CN
Inventors: 永田佳秀; 佐藤敦; 渡边一十六; 金志优
Original assignee: Cheil Industries Inc
Current assignee: Cheil Industries Inc
Priority date: 2007-06-28
Filing date: 2007-06-28
Publication date: 2015-11-25
Anticipated expiration: 2027-06-28
Also published as: CN101334497A

Abstract

A kind of polarized light splitting device, comprise the non-transmissive layer on the transmission matrix component of the pattern of the ridge had on base portion and described base portion and described ridge, wherein, described non-transmissive layer comprises photo-emission part and divides and light absorption part.Described polarized light splitting device comprises: transmission matrix component, and it has the pattern of the ridge on base portion and described base portion, and the non-transmissive layer on ridge, wherein, non-transmissive layer comprises: photo-emission part divides, and light absorption part, wherein, non-transmissive layer be included in further photo-emission part divide and light absorption department divide between center section, the reflectivity of center section is less than reflectivity that photo-emission part divides and is greater than the reflectivity of light absorption part, wherein non-transmissive layer presents the gradual change of reflectivity, the gradual change of reflectivity has the densifie state of reflection and the rarefaction of absorption, wherein, photo-emission part divides, center section and described light absorption part is each has identical material composition, center section presents the gradual change of reflectivity.

Description

Polarization beam splitter, method and apparatus for manufacturing the same, and display including the same

Technical Field

Exemplary embodiments relate to a polarization splitting device, a display including the same, a method of manufacturing the same, and an apparatus for manufacturing the same, and more particularly, to a wire grid type polarization splitting device.

Background

In general, LCD devices used in monitors of mobile phones, PDAs, laptop and desktop computers, LCD televisions, and the like may include a liquid crystal layer disposed between polarization beam splitting devices such as polarizing films and a backlight unit (BLU) providing illumination thereto.

Dichroic polarizing films are commonly used. However, the dichroic polarizing film is limited in that the light utilization efficiency is theoretically not more than 50% because the dichroic polarizing film absorbs light polarized perpendicular to the transmission axis.

For this reason, a reflective polarization splitting device has been proposed, which can increase the light utilization efficiency by reflecting the non-transmitted component of polarized light back to the BLU to reuse the component. In particular, a wire grid type polarization splitting device is proposed, which may comprise a "wire grid", e.g. a pattern of substantially parallel ridges with a conducting material on it, having a pitch smaller than the wavelength of the incident light, so as to transmit light polarized perpendicular to the grid and reflect light polarized parallel to the grid. However, there is a need for a large-sized polarization beam splitting device that is simple and economical to manufacture, and that can be used for a liquid crystal display device in mobile phones, Personal Digital Assistants (PDAs), monitors for laptop and desktop computers, LCD televisions, and the like.

Disclosure of Invention

Accordingly, exemplary embodiments are directed to a polarization splitting device, a display including the same, a method of manufacturing the same, and an apparatus for manufacturing the same that substantially obviate one or more of the problems due to limitations and disadvantages of the related art.

It is therefore a feature of an embodiment to provide a polarization splitting device having a reflective portion and an absorbing portion stacked in this order.

It is therefore another feature of an embodiment to provide a polarization splitting device having a reflective portion and an absorbing portion and an intervening intermediate portion, wherein a reflectivity of the intermediate portion is less than a reflectivity of the reflective portion and greater than a reflectivity of the absorbing portion.

The light reflecting portion and the light absorbing portion may each have the same material composition. The light reflecting portion may have a first material composition, and the light absorbing portion may have a second material composition different from the first material composition. The first material composition may include a metal and the second material composition may include a metal oxide and/or carbon.

Forming the non-transmissive layer may include depositing the non-transmissive layer by changing a deposition angle according to a height of the non-transmissive layer. The light reflecting portion and the light absorbing portion may each have the same material composition. Forming the non-transmissive layer may include applying the material composition from at least two different angles relative to the base, a first angle of the at least two angles corresponding to the light-reflecting portion and a second angle of the at least two angles corresponding to the light-absorbing portion.

Forming the non-transmissive layer may include applying the material composition from at least two different ranges of angles, a first range of the at least two ranges corresponding to light-reflecting portions and a second range of the at least two ranges corresponding to light-absorbing portions. The deposition angle (θ H) in the deposition sub-process of forming the light reflecting portion may have a range of θ 2 ≦ θ H ≦ θ 1(θ 2 < θ 1), the deposition angle (θ H) being an angle with respect to a normal to the deposition surface, the deposition angle (θ L) in the deposition sub-process of forming the light absorbing portion may have a range of θ 3 ≦ θ L ≦ θ 4(θ 3 < θ 4), the deposition angle (θ L) being an angle with respect to the normal to the deposition surface, and θ 1, θ 2, θ 3, and θ 4 may satisfy the following conditions: theta 1 is more than or equal to 40 degrees and less than or equal to 70 degrees, theta 2 is more than or equal to 20 degrees and less than or equal to 50 degrees, theta 3 is more than or equal to 60 degrees and less than 90 degrees, and theta 4 is more than or equal to 60 degrees and less than or equal to 90 degrees.

The light reflecting portion may have a first material composition, and the light absorbing portion may have a second material composition different from the first material composition. The non-transmissive layer may further include an intermediate portion between the light reflective portion and the light absorbing portion, the intermediate portion having a reflectivity less than that of the light reflective portion and greater than that of the light absorbing portion. Forming the light reflecting portion may include depositing a first material, forming the light absorbing portion may include depositing a second material, and forming the intermediate portion may include depositing a mixture of the first and second materials. The method may include simultaneously depositing a first material and a second material on the transmissive base member from respective first and second locations relative to the transmissive base member, and depositing a mixture of the first and second materials on the transmissive base member from a third location between the first and second locations. The method may further include providing at least one aperture between the first and second locations, and the at least one aperture may be configured to regulate deposition of at least one of the first and second materials.

The method can comprise the following steps: the method includes depositing a material on the ridge along a first direction approximately perpendicular to an extending direction of the ridge across and through the first aperture to form a light reflecting portion, and depositing a material on the light reflecting portion along the first direction across and through the second aperture to form a light absorbing portion.

The method can comprise the following steps: the light absorbing portion is formed by depositing a material on the ridge along a first direction approximately perpendicular to an extending direction of the ridge across and through the first hole to form the light absorbing portion, and depositing a material on the light absorbing portion along the first direction across and through the second hole to form the light reflecting portion.

At least one of the above and other features and advantages may be realized by providing a display device including a liquid crystal panel, a backlight unit, and a polarization splitting device. The polarization beam splitter may include: a transmissive base member having a base and a pattern of ridges on the base; and a non-transmissive layer on the ridge. The non-transmissive layer may include a light reflecting portion and a light absorbing portion.

The backlight unit may be disposed opposite to the ridge such that the base portion is between the backlight unit and the ridge, and the light reflecting portion may be between the ridge and the light absorbing portion. The backlight unit may be disposed opposite the base such that the ridge is between the backlight unit and the base, and the light absorbing portion may be between the ridge and the light reflecting portion.

At least one of the above and other features and advantages may be realized by providing an apparatus for manufacturing a polarization beam splitter comprising a transmissive base member, the apparatus comprising a deposition source, a transport assembly configured to transport the transmissive base member past the deposition source, and an aperture disposed between the deposition source and the transmissive base member, the aperture configured to regulate exposure of the transmissive base member to the deposition source. The apparatus may be configured to deposit the deposition material on the transmissive base member from at least two angular ranges relative to the transmissive base member.

The aperture may be configured to limit exposure of the transmissive base member to the deposition source to a first range of the at least two angular ranges, and the apparatus may further include a second aperture disposed between the deposition source and the transmissive base member, the second aperture configured to limit exposure of the transmissive base member to the deposition source to a second range of the at least two angular ranges.

The deposition source may be configured to deposit a first deposition material on the transmissive base member in a first range of the at least two angular ranges, and the apparatus may further comprise a second deposition source configured to deposit a second material on the transmissive base member in a second range of the at least two angular ranges.

Drawings

The above and other objects, features and other advantages will become more apparent to those skilled in the art by describing in detail exemplary embodiments thereof with reference to the attached drawings, in which:

FIG. 1 illustrates a schematic perspective view of an exemplary embodiment of a polarization splitting device;

FIG. 2 illustrates a cross-sectional view taken along line A-A in FIG. 1;

FIG. 3 illustrates a schematic diagram of an exemplary embodiment of an apparatus for fabricating a polarization splitting device;

FIG. 4 illustrates an enlarged view of portion "a" in FIG. 3;

FIG. 5 illustrates an enlarged view of portion "b" of FIG. 3;

FIG. 6 illustrates an enlarged view of portion "c" of FIG. 3;

FIG. 7 illustrates a graph showing a relationship between the reflectance of a deposition material and a deposition angle;

FIG. 8 illustrates a schematic cross-sectional view of another exemplary embodiment of a polarization splitting device;

FIG. 9 illustrates a schematic diagram of another exemplary embodiment of an apparatus for fabricating a polarization splitting device; and

fig. 10a and 10b illustrate schematic cross-sectional views of exemplary embodiments of a polarization splitting device and a comparison device, respectively.

Detailed Description

Japanese patent application No.2006-178415 entitled "Polarized-light splitting device and manufacturing method of" filed in the Japanese patent office at 28.2006 is hereby incorporated by reference in its entirety.

Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings; the exemplary embodiments may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In the drawings, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. Further, it will be understood that when a layer is referred to as being "under" another layer, it can be directly under the other layer, or one or more intervening layers may also be present. In addition, it will also be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. Like numbers refer to like elements herein.

Fig. 1 illustrates a perspective schematic view of a polarization splitting device 10(20, 30, 40) according to first to fourth exemplary embodiments. The polarization beam splitter 10(20, 30, 40) can separate polarized light components by transmitting or reflecting incident light according to the polarization direction of the incident light. Polarizing beam splitter 10(20, 30, 40) may be a film-type Wire Grid Polarizer (WGP) with a diffraction grating having a pitch smaller than the wavelength of the incident light. The polarizing beam splitter 10(20, 30, 40) may comprise a transmissive base member 1, e.g. a transmissive film, which may have a small relief pattern on its surface, e.g. a pattern of substantially parallel ridges with corresponding valleys between the ridges. The non-transmissive layer 2 may be provided thereon on the front end, i.e., the ridge, of the convex portion of the transmissive base member 1.

The transmission base member 1 may include a plurality of gate portions 1b, i.e., convex (ridge) portions, which may have a predetermined width W and may be formed on the film-shaped base 1a substantially in parallel with each other with a gate of a pitch P (see fig. 2 and 8). Here, the gate pitch P may be a very small gap, e.g., narrower than a predetermined wavelength of incident light.

For example, when used in an LCD device, the polarization splitting device 10 may split polarized light in the visible range, such as light produced by a BLU. In this case, the gate pitch P may be half the wavelength of visible light or less. In one implementation, the gate pitch P may be less than about 200nm, such as less than about 150 nm. In another implementation, the pitch P may be less than about one-fifth the wavelength of visible light.

The ratio of the pitch P to the width W of the gate portion 1b may be about 1 to about 0.5, i.e., the value of W/P may be about 1 to about 0.5. In one implementation, the value of W/P may be adjusted within a range of about 0.3, such as 0.5 0.3 (0.2W/P0.8), as may be appropriate for a particular application. In this regard, when adjusting the value of W/P, if the value of W/P is less than about 0.5, the degree of polarization may be slightly reduced, and the amount of transmitted light may be increased.

The transmission-based member 1 may be made of, for example, a synthetic resin selected to transmit an appropriate amount of light in a selected wavelength range. The synthetic resin may include, for example, polyethylene terephthalate (PET), Polycarbonate (PC), and/or polymethyl methacrylate (PMMA).

It is not necessary that the entire surface of the transmission base member 1 is flat. Preferably, the surface is shaped not to block light transmission too much.

Fig. 2 illustrates a cross-sectional view taken along line a-a in fig. 1 according to the first and third exemplary embodiments.

A first exemplary embodiment of the polarization splitting device 10 will now be described with reference to fig. 1 and 2.

Referring to fig. 2, the non-transmissive layer 2 may exhibit a reflectivity decreasing from a lower portion thereof to an upper portion thereof. The change in reflectivity may be gradual or gradual, and may be monotonic. More specifically, the non-transmissive layer 2 may be deposited on the transmissive base member 1 and may include a high-reflectance portion 2a provided on a front or convex surface of the gate portion 1b and a low-reflectance portion 2b provided on an uppermost portion of the non-transmissive layer 2. The high-reflectance portion 2a and the low-reflectance portion 2b may be macroscopically characterized as a reflective surface and a light-absorbing surface, respectively. However, the high-reflectance portion 2a and the low-reflectance portion 2b may be microscopically characterized as portions of the non-transmissive layer 2 that perform light reflection and light absorption, respectively. As used herein, light absorption refers to a reflectance level that is less than the reflectance level of the light reflecting portion 2a facing the light source.

The low-reflectance portion 2b may allow light to be transmitted to some extent. However, the low-reflectance portions 2b may exhibit light absorption, so that light transmitted into the non-transmissive layer 2 is not transmitted through the low-reflectance portions 2 b. For this reason, the light-transmitting protective coating may be formed separately from the low-reflectance portion 2b, for example.

The change in reflectivity of the non-transmissive layer 2 may be achieved by, for example, changing the amount, composition, and/or structure of the deposited material in the non-transmissive layer 2. In one implementation, a reflective material such as aluminum may be used as the deposition material. The non-transmissive layer 2 may be formed by changing the deposition angle of the material during the formation of the non-transmissive layer 2 such that the structure of the deposited material changes from a dense state (reflective) to a loose state (absorptive). Aluminum may be particularly suitable because, depending on the angle of deposition, aluminum may exhibit significant reflectivity variation. However, other materials, such as silver, may exhibit the desired change in reflectivity over the wavelength range of visible light.

In an implementation, the non-transmissive layer 2 may further include an intermediate portion 2c provided between the high-reflectance portion 2a and the low-reflectance portion 2b and having an intermediate reflectance. In case the non-transmissive layer 2 comprises an intermediate portion 2c, the intermediate portion 2c may exhibit a gradual change of reflectivity. Once the reflectances of the high-reflectance portion 2a and the low-reflectance portion 2b are appropriately determined, the change in the reflectance of the intermediate portion 2c can be appropriately determined. For example, the amount, composition, and/or structure of the material can be varied. In forming the intermediate portion 2c, it may be desirable to consider the influence of the intermediate portion 2c on the total intensity of the non-transmissive layer 2. In an implementation, the composition of the intermediate portion 2c may vary, for example, monotonically. For example, the non-transmissive layer 2 may be formed in a three-layer structure such that the high-reflectance portions 2a and the low-reflectance portions 2b have a suitably large thickness to perform respective reflection and absorption functions, and the composition of the middle portion 2c may smoothly vary between the high-reflectance portions 2a and the low-reflectance portions 2 b. In another implementation, the reflectivity of the non-transmissive layer 2 may vary stepwise, e.g. as with a multilayer structure. In this regard, it may be desirable to avoid large abrupt changes in reflectivity, for example, at the boundaries between layers.

The reflectance of the high reflectance section 2a may be high to increase the light utilization efficiency of the polarization splitting device 10. Further, the reflectance of the low reflectance part 2b may be low to increase the contrast of the polarization splitting device 10. In one implementation, the low-reflectance portion 2b may have a reflectance of less than about 40%, such as about 30% or less.

In operation, for incident light traveling from a light source such as the BLU205 toward the rear surface of the gate portion 1b of the transmission base member 1, the polarization splitting device 10 may transmit light having a polarization component in one direction, but may reflect light having a polarization component in the other direction. The reflected light may be reflected back to the light source.

For example, referring to fig. 2, when a light source such as a BLU205 is disposed under the polarization splitting device 10 (for example, on the side opposite to the LCD panel 210 in the display) and irradiates light to the polarization splitting device 10, a Transverse Magnetic (TM) wave component 3M (whose electric field vibration direction is perpendicular to the gate direction, i.e., left to right in fig. 2, which is the extending direction of the ridge, perpendicular to the paper surface of fig. 2) of the polarization splitting device 10 may be transmitted upward through the gate portion 1 b.

On the other hand, a Transverse Electric (TE) wave component 3E (whose electric field vibration direction is parallel to the grating direction, i.e., inside-out of the plane of fig. 2) cannot be transmitted through the grating portion 1b but can be reflected by the high-reflectance portion 2a, so that the reflected light component 3R is returned to the light source. The reflected light component 3R can then be repeatedly reflected in the device and re-irradiated onto the polarization splitting device 10. In this way, since the reflected light component 3R can be reused by reflection, not absorbed, the light use efficiency can be increased.

Also, when light is irradiated onto the polarization beam splitting device 10 from the outside, i.e., from above in fig. 2, the TM wave component 4M may be transmitted through the transmission base member 1, and the TE wave component 4E may not be transmitted. The TE wave component 4E may be at least partially absorbed by the low reflectance element 2 b. In this way, since the low-reflectance part 2b may have a relatively low reflectance, a portion of light may be absorbed in the low-reflectance part 2b, thereby attenuating the amount of light reflected upward and thus enhancing the contrast of a displayed image. When the polarization splitting device 10 is used in an LCD device, the TM wave component 4M and the TE wave component 4E may correspond to external light.

Hereinafter, a method and apparatus for manufacturing the polarization beam splitting device 10 according to the first exemplary embodiment will be described.

When a metal or a metal compound is used as the deposition material, the reflectivity of the deposition material may depend on the deposition angle. The method and apparatus to be described use this property to change the reflectivity of the non-transmissive layer 2 by changing the angle of deposition.

Fig. 3 illustrates a schematic diagram of an exemplary embodiment of an apparatus for manufacturing the polarization splitting device 10, and fig. 4 to 6 illustrate enlarged views of portions "a", "b", and "c" in fig. 3, respectively. Further, fig. 7 illustrates a graph showing a relationship between the reflectance of the deposition material and the deposition angle. In fig. 7, the horizontal axis indicates a deposition angle (°), and the vertical axis indicates a reflectance (%) at a wavelength of 550 nm.

The polarization beam splitting device manufacturing apparatus 100 shown in fig. 3 may be used to manufacture the above-described polarization beam splitting device 10, and may include a cooling drum 5, guide rollers 6 and 7, a deposition source 9, and a deposition-adjusting hole such as a deposition shield 8. The deposition shield 8 may be fixed to the deposition angle determining member or may be a part of the deposition angle determining member. These components may be contained in a vacuum chamber (not shown).

The cooling drum 5 can cool the transmission base member 1 to stabilize the temperature thereof, and can convey the transmission base member 1 in the circumferential direction of the cooling drum 5. Referring to fig. 3, when the polarization beam splitting device 10 is formed, the cooling drum 5 may be rotated clockwise at a constant speed by a motor (not shown). The rotational axis of the cooling drum 5 may be disposed in a direction perpendicular to the sheet surface of fig. 3 such that the rotational axis of the cooling drum 5 extends perpendicular to the sheet surface of fig. 3.

The guide roller 6 is rotatable together with the cooling drum 5, and can guide the conveyance of the transmission base member 1 to the cooling drum 5.

The concave-convex pattern (see fig. 4), i.e., the grating portion 1b, of the transmission base member 1 may extend in the same direction as the rotational shaft of the cooling drum 5, i.e., the extending direction may be perpendicular to the paper surface of fig. 3. The base 1a may be wound around the cooling drum 5 and conveyed by the rotation of the cooling drum 5.

The guide roller 7 may rotate together with the cooling drum 5 and guide the conveyance of the transmission base member 1 having the non-transmission layer 2 formed thereon when it is released from the cooling drum 5.

The deposition source 9 may be configured to deposit the deposition material 11 on the transmissive base member 1, and may heat and eject the deposition material 11. In this exemplary embodiment, the deposition source 9 may be located approximately in the middle of the transport path of the transmission base member 1 below the cooling drum 5. Accordingly, the deposition material 11 may diffuse upward and may spread radially. In this exemplary embodiment, the central axis of the jetting of the deposition material 11 may be substantially in the vertical direction in fig. 3.

The deposition shield 8 may be located between the deposition source 9 and the cooling drum 5, and may partially cover the cooling drum 5. The deposition shield 8 may comprise one or more apertures. In one implementation, the deposition shield 8 may include two apertures 8a and 8b, each having a predetermined width. The holes 8a and 8b can determine the position where the deposition material 11 is ejected onto the transmission base member 1 through the deposition shield 8 when the transmission base member 1 is conveyed by the cooling drum 5.

The hole 8a may be located on an upstream side of the transmission base member 1 conveyance direction with respect to a central axis of the ejection of the deposition material 11. As shown in an enlarged view of a portion "b" in fig. 5, the deposition angle (with respect to the normal direction of the transmission base member 1 when the transmission base member 1 is conveyed along the circumference of the cooling drum 5) may be shifted from the normal direction to the downstream side of the conveying direction, wherein the shift varies within an angular range when the transmission base member 1 is carried through the hole 8a along the cooling drum 5. The deposition angle may vary within an angular range starting at an angle θ 1 on the upstream side of the conveyance direction and ending at an angle θ 2 on the downstream side of the conveyance direction. In one implementation, θ 1 can be greater than θ 2 for the holes 8a, 40 ° ≦ θ 1 ≦ 70 °, and 20 ° ≦ θ 2 ≦ 50 °.

The hole 8b may be located on a downstream side of the conveyance direction of the transmission base member 1 with respect to the central axis of the ejection of the deposition material 11. As shown in the enlarged portion of "c" in fig. 6, the deposition angle with respect to the normal direction of the transmission base member 1 conveyed along the circumference of the cooling drum 5 may be offset from the normal direction to the upstream side of the conveying direction, wherein the offset varies within an angular range as the transmission base member 1 is carried through the hole 8b along the cooling drum 5. The deposition angle may vary within an angular range starting at an angle θ 3 on the upstream side of the conveyance direction and ending at an angle θ 4 on the downstream side of the conveyance direction. In one implementation, for the holes 8b, θ 3 can be less than θ 4, 60 ≦ θ 3 < 90 °, and 60 ≦ θ 4 < 90 °.

Next, a method of manufacturing the polarization splitting device 10 using the manufacturing apparatus 100 will be described.

The transmission base member 1 may be manufactured by an appropriate process such as an imprint (imprint) process to form thereon a grating portion 1b, e.g., a concave-convex pattern of ridges. The imprinting process may include forming a master mold having a fine structure, for example, using operations such as electron beam lithography and/or etching, and transcribing the shape of the mold to a plastic film. The imprinting process may provide advantages of mass-scale and low cost compared to a method of forming a concave-convex pattern directly by patterning a film using photolithography and etching.

The transmission base member 1 may be guided by the guide roller 6 and wound around the cooling drum 5 with the grating portions 1b oriented outward, i.e., away from the cooling drum 5 in the radial direction of the cooling drum 5. The transmission base member 1 may be conveyed along the circumference of the cooling drum 5.

When the transported transmission base member 1 reaches the region where the deposition material 11 is ejected through the hole 8a (point V1 in fig. 5), the first deposition sub-process may start, in which the deposited deposition material 11 starts to form the high-reflectance lower portion 2a of the non-transmission layer 2. Specifically, the convex surface of the gate portion 1b may be coated with the deposition material 11, and the deposition material 11 is ejected through the hole 8a from the deposition angle θ 1. When the transmission base member 1 is conveyed across the hole 8a with the rotation of the cooling drum 5, the deposition process may continue while the deposition angle is continuously changed up to the angle θ 2, thereby completing the formation of the lower portion 2a of the non-transmission layer 2. Here, the first deposition sub-process may end when the transmission base member 1 reaches a position (point V2 in fig. 5) where the mask 8 blocks the deposition of the deposition material 11.

When the transported transmission base member 1 reaches the region where the deposition material 11 is ejected through the hole 8b (point V3 in fig. 6), the second deposition sub-process may start, in which the deposited deposition material 11 starts to form the upper portion 2b of the non-transmissive layer 2 of low reflectance. Specifically, the upper portion 2b may be formed of the deposition material 11 on the lower portion 2a formed in the first deposition sub-process, the deposition material 11 being ejected through the void 8b within a deposition angle range starting at an angle θ 3. While the transmissive base member 1 is conveyed across the hole, the deposition process may continue while the deposition angle is continuously changed to the angle θ 4, thereby completing the formation of the upper portion 2b of the non-transmissive layer 2. Here, the second deposition sub-process may end when the transmission base member 1 reaches a position (point V4 in fig. 6) where the mask blocks the deposition of the deposition material 11.

After the non-transmissive layer 2 is completely formed on the transmissive base member 1, for example, by a deposition process, the transmissive base member 1 with the non-transmissive layer 2 may be conveyed out of the manufacturing apparatus 100 by a guide roller 7.

Fig. 7 illustrates a graph showing a relationship between the reflectance of the deposition material and the deposition angle. The case shown in fig. 7 is an experimental result of measuring the reflectance of a plastic film (the same material as that of the transmission base member 1) on which an aluminum deposition layer is formed by changing the deposition angle. As seen in fig. 7, the reflectivity change corresponds approximately to line 200 in the graph. Therefore, in the normal direction (deposition angle is 0 °) of the deposition surface, the reflectance is maximum, and decreases in proportion to the inclination with respect to the normal direction.

Without being bound by any particular theory, the above-described reflectance variation is considered to be because the thin film is densely and uniformly formed when the deposition angle is small, and the composition of the thin film is in a looser state when the deposition angle is large. Thus, although aluminum may be highly reflective, if the deposition angle is large, the corresponding aluminum deposition sample may be dark and may have low reflectivity and low brightness.

In an implementation, the first deposition sub-process may form the high-reflectance part 2a on the convex surface of the gate part 1b, and may form a part (whose reflectance is gradually reduced) of the middle part 2c on the high-reflectance part 2 a. The second deposition sub-process may form the remaining portion (whose reflectivity is gradually reduced) of the middle portion 2c and the low-reflectivity portion 2 b.

As described above, the hole 8a may be used to form the high-reflectance portion 2a, and the hole 8b may be used to form the low-reflectance portion 2b, depending on the positional relationship between the deposition source 9 and the deposition shield 8.

In an implementation, if the deposition angle θ 2 is set equal to the deposition angle θ 3(θ 2 — θ 3), the intermediate portion 2c may be formed such that the reflectivity thereof gradually and continuously changes.

In another implementation, if the deposition angle θ 2 is set to be smaller than the deposition angle θ 3(θ 2 < θ 3), the middle portion 2c may be formed such that the reflectivity varies discontinuously, the discontinuity being formed by an interface of surfaces having different reflectivities. It will be appreciated that this discontinuity in reflectivity may be significantly less than the difference in reflectivity of the high reflectivity portions 2a and the low reflectivity portions 2 b.

In this case, since the discontinuous surface may be made of the same material, and structural inconsistency may be relatively small as compared to directly combining the structure of the high-reflectance part 2a with a different structure of the low-reflectance part 2b, brittleness of the resulting structure may be reduced, adhesion between the parts 2a and 2b may be increased, and manufacturing may be facilitated.

The deposition process may be performed by changing a deposition angle according to a layer height of the deposition layer. The deposition portions 2a and 2b may be formed using the same deposition material 11, and the reflectivity thereof may be gradually changed. Also, the deposition process may be divided into first and second deposition sub-processes that may have different deposition angle ranges. Thus, a deposited layer with a significant change in reflectivity can be easily formed compared to, for example, a single continuous deposition process. In addition, since the non-transmissive layer 2 may be formed of the same deposition material, structural integrity at the boundary formed thereby may be enhanced even in the case where the non-transmissive layer 2 is formed by different first and second deposition sub-processes. Furthermore, even though the deposition angle may vary discontinuously, the integrity of the deposited layer may be improved, which may help avoid problems such as gate collapse, enabling the formation of reliable Wire Grid Polarizers (WGPs).

In the above-described embodiment, for the hole 8a, 20 ° ≦ θ 2 ≦ 50 °, and for the hole 8b, 60 ° ≦ θ 3 ≦ 90 °. Also, as described above, in another implementation, the deposition angle θ 2 may be set equal to the deposition angle θ 3(θ 2 — θ 3). It should also be appreciated that in yet another implementation, it may be desirable to set θ 2 > θ 3 such that the respective deposition sub-processes may include a common angular range, i.e., they may overlap, as desired.

Hereinafter, the influence of the deposition angle on the shapes of the non-transmissive layer 2 and the gate will be described.

When the non-transmissive layer 2 is deposited on the convex surface (ridge) of the gate 1b formed with the concavo-convex (ridge-valley) pattern having a pitch smaller than the wavelength of light, the shape of the deposited layer may be changed according to the deposition angle. Therefore, it may be difficult to form the gate to have a desired profile. Specifically, if the deposition angle is too small, the deposition layers on two adjacent gate portions 1b may become connected such that the concave portions (i.e., intervening valley portions through which incident light is transmitted) are blocked or partially blocked. On the other hand, if the deposition angle is too large, a bias may be generated at the deposited layer and a biased gate may be formed. Therefore, it may be desirable to set the range of deposition angles in consideration of the influence of the deposition angles on the gate shape.

In table 1 below, the reflectance and the gate shape generated after forming a deposition layer having the same thickness on the transmission base member 1 at a fixed deposition angle are shown. The deposition angle is determined as a difference from the normal direction of the transmission base member 1. In the column of "gate shapes", the most preferred gate shape is denoted by "1", other gate shapes that may be desirable are denoted by "2", and gate shapes that may include undesirable characteristics are denoted by "3". Specific comments regarding the gate shape are described in the "appearance" column.

TABLE 1

Deposition angle (°)	Reflectivity of light	Grid shape	Appearance of the product
				0	Height of	3	Upper parts of adjacent grids are connected
10	Height of	3	Upper parts of adjacent grids are connected
				20	Height of	2	The upper parts of adjacent grids are partially connected
30	In	2
				40	In	1
50	In	1
				60	In	2
70	Is low in	2	Large grid inclination

80	Is low in	3	Large grid inclination
				90	Is low in	3	Large grid inclination

As described in table 1, the deposition angle that produces the most preferred and desirable gate shape is in the range of about 30 ° to about 60 °. Referring to fig. 7, the deposition angle ranges of about 30 ° to about 60 ° correspond to the reflectance ranges of about 67% to about 40%, respectively. The above results were obtained from experiments performed under conditions where deposition was performed at a constant deposition angle.

When deposition is performed by changing the deposition angle, the time required for forming a thin film depends on the deposition conditions in order for the deposition material to cover the entire deposition surface and form a desired reflective surface. Therefore, the deposition angle at the start or end point of the film formation time may not have a considerable influence on the characteristics of the film. Therefore, the above-described angle range can be appropriately extended to a range of, for example, 20 ° to 70 °.

In some cases, deposition angles in excess of 70 ° may result in deflection of the film. However, this may be avoided or may be insignificant when the thickness of the deposited film is thin. In this exemplary embodiment, since the first deposition sub-process is performed in a range in which the inclination of the gate is not generated and then the second deposition sub-process is performed under the condition of a large deposition angle, the height of the layer in the range of the large deposition angle becomes low and it is possible to form a superior gate shape using an angle range wider than that used in the experimental result shown in fig. 7. In other implementations, it may also be possible to set the deposition angle θ 4 to 90 ° while forming a good gate shape, as described in more detail below. Thus, it should be understood that the angular ranges for θ 1, θ 2, θ 3, and θ 4 may be adjusted relative to the upper and lower limits of the deposition angles of the deposition sub-process.

Fig. 8 illustrates a cross-sectional view taken along line a-a in fig. 1 according to the second and fourth exemplary embodiments.

A second embodiment of the polarization splitting device 20 will be described with reference to fig. 8.

Referring to fig. 8, the polarization splitting device 20 of this exemplary embodiment may be configured such that the non-transmissive layer 2' of the polarization splitting device 10 of the above-described first exemplary embodiment is upside down on the gate portion 1 b. The polarization splitting device 20 according to the second exemplary embodiment may be configured to be used with a BLU205, the BLU205 being disposed on the side of the film having the concave-convex pattern, i.e., on the opposite side of the configuration described above in connection with fig. 2.

The polarization splitting device 20 may be configured such that when light is irradiated toward the non-transmissive layer 2 ', the TM wave component 3M is transmitted through the polarization splitting device 20, the TE wave component 3E is reflected by the high-reflectance portion 2 a', and the reflected light component 3R is guided back to the light source such as BLU. By disposing the light source such as the BLU205 to face the non-transmissive layer 2', the polarization splitting device 20 may be used in an LCD device, wherein the polarization splitting device 20 of this exemplary embodiment has the same operational effects as the polarization splitting device 10 of the first exemplary embodiment. Further, it may be desirable to dispose the non-transmissive layer 2' on the inner side, as shown in fig. 8.

When the transmission base member 1 is disposed outside the polarization splitting device 20, the transmission base member 1 may be made of a material that has a low birefringence and does not scatter polarized light even when a deformation process such as elongation is applied thereto. Therefore, it may be preferable that the transmission base member 1 does not re-scatter the polarized light separated by the function of the polarization splitting device 20.

When the polarization splitting device 20 is manufactured using the manufacturing apparatus 100, the polarization splitting device 20 can be easily manufactured only by exchanging the conditions of the deposition angle of the first deposition sub-process of the first exemplary embodiment with the conditions of the deposition angle of the second deposition sub-process, i.e., reversing the above-described first and second sub-processes. For example, the arrangement of the deposition shield 8 may be configured such that the deposition angles θ 1, θ 2, θ 3, and θ 4 of this second exemplary embodiment correspond to the deposition angles θ 4, θ 3, θ 2, and θ 1 of the first exemplary embodiment, respectively. Alternatively, the conveyance direction of the transmission base member 1 may be reversed by rotating the cooling drum 5 counterclockwise, the arrangement of the deposition hoods 8a and 8b may be reversed left/right (refer to fig. 3), or the like. Since only the positional relationship of the high-reflectance portion 2a ' and the low-reflectance portion 2b ' with respect to the transmission base member 1 is different from that of the first exemplary embodiment, the non-transmissive layer 2 ' of this second exemplary embodiment can have the same operational effects as the non-transmissive layer 2 of the first exemplary embodiment.

The manufacturing method according to this second exemplary embodiment may have a feature in which no gate-like inclination is generated at the upper portion 2a 'of the non-transmissive layer 2 because the deposition angle when the upper portion 2 a' of the non-transmissive layer 2 (lower side in fig. 8) is formed is smaller than the deposition angle when the polarization splitting device 10 is formed.

In the first and second exemplary embodiments described in conjunction with fig. 2 and 8, the polarizing film manufacturing apparatus 100 can continuously convey the light-transmitting substrate 1 in the direction perpendicular to the extending direction of the small concavo-convex pattern through the rear surface of the supporting base 1a, wherein the grating portions 1b of the light-transmitting substrate 1 are formed in the concavo-convex pattern extending in the extending direction, and the non-transmissive layers 2, 2' can be deposited on the conveyed light-transmitting substrate 1. The manufacturing apparatus may include at least one deposition source 9 disposed opposite to the light-transmitting substrate 1, a deposition angle determining member that may be disposed between the deposition source 9 and the base member 1, and two or more holes 8a, 8b for the deposition source 9 along a conveyance direction of the base member 1.

Using the manufacturing apparatus 100, the deposition process may be performed by changing the deposition angle with respect to the normal direction of the base member 1 from a relatively small value to a relatively large value, or from a relatively large value to a relatively small value along the conveyance direction of the base member 1. Using the deposition angle determining member together with the single deposition source 9 and the two holes 8a, 8b corresponding to the single deposition source 9 can produce high-reflectance deposition portions 2a, 2a 'formed at a relatively small deposition angle and low-reflectance deposition portions 2b, 2 b' formed at a relatively large deposition angle. The two deposition sub-processes may be performed by arranging the high-reflectance deposition portions 2a, 2a ' and the low-reflectance deposition portions 2b, 2b ' on the conveyance path of the base member 1 in the order from high reflectance to low reflectance or in the reverse order, so that the composition of the non-transmissive layers 2, 2 ' changes from high reflectance to low reflectance or from low reflectance to high reflectance when the base member 1 is moved in the conveyance direction. In this way, the respective reflectance sections 2a, 2a 'and 2b, 2 b' of the polarization splitting devices 10, 20 may be formed in sequence along the conveyance direction of the base member 1.

Hereinafter, a polarization beam splitting device 30 according to a third exemplary embodiment, in which a plurality of materials are used to manufacture the device, will be described.

Referring again to fig. 2, the polarization splitting device 30 according to the third exemplary embodiment may include a high-reflectance part 2A, a low-reflectance part 2B, and an intermediate part 2C instead of the high-reflectance part 2A, the low-reflectance part 2B, and the intermediate part 2C of the polarization splitting device 10 according to the first exemplary embodiment. In the following description, in order to avoid repetition, only those aspects of the device 30 and its manufacture that differ significantly from those of the first embodiment will be described.

In the third exemplary embodiment, the gradual change in the reflectivity of the non-transmissive layer 2 may be achieved by changing the amount and/or composition of the deposited material.

Similarly to the first exemplary embodiment, a metal material having high reflectivity in the visible wavelength range, such as aluminum or silver, may be used as the deposition material of the high-reflectivity portions 2A.

A material having a lower reflectance than the high reflectance part 2A and/or a material having light absorption can be used as the deposition material of the low reflectance part 2B. For example, the deposition material of the low-reflectivity portion 2B may include one or more metals, metal oxides, carbon, etc. having relatively low reflectivity.

The middle portion 2C may be implemented by a mixture of deposition materials of the high-reflectance portion 2A and the low-reflectance portion 2B. Accordingly, the reflectivity of the middle portion 2C may have a value between the reflectivity of the high-reflectivity portion 2A and the reflectivity of the low-reflectivity portion 2B.

In general, when depositing different materials, adhesion between layers may be weak, brittleness may increase, and manufacturing may become difficult. However, according to the third exemplary embodiment, the composition ratio of the material of the high-reflectance part 2A to the material of the low-reflectance part 2B may be gradually changed in the middle part 2C between the high-reflectance part 2A and the low-reflectance part 2B. In this way, a reduction in adhesion between the layers may be reduced or prevented.

The non-transmissive layer 2 ″ according to the third exemplary embodiment may include: an upper layer 2B and a lower layer 2A, which may comprise different deposition materials having different amounts and/or compositions; and an intermediate layer 2C between the upper layer 2B and the lower layer 2A, which may comprise a mixture of different deposition materials having different amounts and/or compositions. In this case, even if the upper layer 2B and the lower layer 2A are made of different deposition materials having different amounts and/or compositions, since the intermediate layer 2C may be made of a mixture of different deposition materials and provided between the upper layer 2B and the lower layer 2A, a significant discontinuity between the surfaces of the materials of different amounts/compositions can be avoided. Thus, the integrity of the non-transmissive layer 2 "may be enhanced, which may reduce or eliminate defects such as gate collapse, resulting in a highly reliable polarization splitting device 30.

Hereinafter, a method and apparatus 110 for manufacturing the polarization splitting device 30 will be described with reference to fig. 9.

Fig. 9 illustrates a schematic diagram of an exemplary embodiment of an apparatus 110 for manufacturing a polarization splitting device 30. Referring to fig. 9, the manufacturing apparatus 110 may be used to manufacture the polarization splitting device 30 and may include the high-reflectance material deposition source 15 and the low-reflectance material deposition source 16 instead of the single deposition source 9 used in the manufacturing apparatus 100 of the first exemplary embodiment. The apparatus 110 may further include a deposition shield 12 and a mask 14 instead of the deposition shield 8 used in the manufacturing apparatus 100 of the first exemplary embodiment. In the following description, in order to avoid repetition, only those aspects of the method and apparatus 110 that differ significantly from those of the first exemplary embodiment will be described.

The high-reflectivity material deposition source 15 and the low-reflectivity material deposition source 16 may heat and eject the respective deposition materials 17 and 18, and the deposition materials 17 and 18 are used to form the high-reflectivity portions 2A and the low-reflectivity portions 2B, respectively. The high-reflectance material deposition source 15 and the low-reflectance material deposition source 16 may be located on the upstream side and the downstream side of the conveyance path of the transmission base member 1, respectively, opposite to each other, below the cooling drum 5. Therefore, the deposition material 17 may be diffused obliquely upward and leftward, and may be radially dispersed toward the upstream side in the conveyance direction. The deposition material 18 may be diffused obliquely upward and rightward, and may be dispersed radially toward the downstream side in the conveyance direction. In one implementation, the high-reflectance material deposition source 15 and the low-reflectance material deposition source 16 may be disposed substantially symmetrically to each other.

The deposition shield 12 may be located between the deposition sources 15 and 16 and the cooling drum 5, and may partially cover the cooling drum 5. Holes 12a, 12b, and 12c may be formed in the deposition shield 12 with a predetermined width, and deposition materials 17 and 18 may be sprayed onto the transmissive base member 1 through the holes 12a, 12b, and 12 c.

The holes 12a, 12b, and 12c may be arranged in order from the upstream side in the conveying direction to the downstream side in the conveying direction. The hole 12a may be located on an upstream side in the conveyance direction with respect to the central axis of the ejection of the deposition material 17, and the hole 12c may be located on a downstream side in the conveyance direction with respect to the central axis of the ejection of the deposition material 18. Also, the hole 12b may be located on a downstream side with respect to the conveyance direction of the central axis of the ejection of the deposition material 17, and on an upstream side with respect to the conveyance direction of the central axis of the ejection of the deposition material 18.

The shroud plate 14 may be fixedly disposed in the middle of the hole 12B to divide the hole 12B into right and left portions 12A and 12B, i.e., an upstream hole 12A on the upstream side in the conveying direction and a downstream hole 12B on the downstream side in the conveying direction. If one end of the hole 12B on the upstream side is defined as the edge S1, the other end of the hole 12B on the downstream side is defined as the edge S3, and one end of the shroud plate 14 on the cooling drum 5 side is defined as the edge S2, the upstream hole 12A may be defined by the edges S1 and S2, and the downstream hole 12B may be defined by the edges S2 and S3.

One or more shadow masks 13 may also be provided to prevent the deposition materials 17 and 18 from diffusing out of the holes 12a and 12 c.

The manufacturing method according to this exemplary embodiment may provide an intermediate deposition sub-process for depositing a mixture of deposition materials 17 and 18 through the hole 12b by disposing two deposition sources 15 and 16 in the conveyance direction of the transmission base member 1 and disposing the hole 12b of the deposition angle determining member between two adjacent deposition sources 15, 16 such that the different deposition materials 17 and 18 ejected from the deposition sources 15 and 16 are mixed at the hole 12 b. Therefore, the intermediate portion 2C can be easily formed by the mixture of the deposition materials 17 and 18 ejected from the two adjacent deposition sources 15 and 16.

The deposition method using the polarized light film manufacturing apparatus 110 may include a first deposition sub-process, a second deposition sub-process, and a third deposition sub-process, which are performed at positions corresponding to the holes 12a, 12c, and 12b, respectively.

In the first deposition sub-process (which corresponds to the first deposition sub-process of the first exemplary embodiment), the deposition material 17 may be diffused through the holes 12A, and the high-reflectance part 2A may be formed of a high-reflectance material.

In the second deposition sub-process (which corresponds to the second deposition sub-process of the first exemplary embodiment), the deposition material 18 may be diffused through the holes 12c and may be deposited on the uppermost portion of the deposition layer formed by the third deposition sub-process (described below). As a result, the low-reflectance portion 2B may be formed of the low-reflectance deposition material 18.

In the third deposition sub-process, the deposition material 17 may diffuse through the upstream hole 12A, while the deposition material 18 may diffuse through the downstream hole 18B. Thus, a mixture of deposition material 17 and deposition material 18 may be deposited to form intermediate layer 2C, which may have a graded structure. At this time, the deposition position of the deposition material and/or the amount of the deposition material may be changed according to the respective deposition angles and/or widths of the holes 12A and 12B. Thus, by adjusting the width and/or position of the upstream-side hole 12A and the downstream-side hole 12B, the mixing ratio of the deposition materials 17 and 18 can be adjusted along the conveying direction. By this adjustment, the composition ratio of the intermediate portion 2C can be controlled and can be varied in a gradual manner, for example.

The composition variations can be adjusted over a wide range. However, it may be desirable to avoid discontinuities between material surfaces that have an effect on the strength of the intermediate portion 2C. For example, when the base member 1 travels from the upstream side to the downstream side, the composition ratio of the intermediate portion 2C may be changed such that the composition ratio of the deposition material 17 gradually decreases and the composition ratio of the deposition material 18 gradually increases.

In one implementation, as described above in connection with the first exemplary embodiment, the low-reflectivity material 18, such as aluminum, may exhibit a reflectivity that varies according to the angle of deposition. In this way, the low-reflectance part 2B may be formed such that the reflectance becomes gradually lower in a similar manner to the second deposition sub-process of the first exemplary embodiment. In this case, the materials 17 and 18 may be the same. The gradual change in reflectivity may be achieved by varying the amount and/or composition of the material. When a material whose reflectance significantly varies depending on the deposition angle is used, it may be desirable to adjust the deposition angle range in a manner similar to the first exemplary embodiment. The range of deposition angles defined by the apertures 12a and the downstream apertures 12B, respectively, may each be equal to the range of deposition angles defined by the apertures 8a of the first embodiment. Similarly, the ranges of deposition angles defined by the holes 12c and the upstream-side holes 12A, respectively, may each be equal to the ranges of deposition angles defined by the holes 8b of the first exemplary embodiment (see reference numerals indicating holes and deposition angles in fig. 5 and 6).

In another implementation, the deposition material 18 may have an inherently low reflectivity that is largely independent of the deposition angle, such that a low reflectivity portion 2B is formed that has a constant reflectivity throughout its thickness. In this case, the deposition angle can be appropriately adjusted. Such inherently low reflectivity materials may include, for example, metal oxides and/or carbon.

Next, a fourth exemplary embodiment will be described with reference to fig. 8, in which the non-transmissive layer 2 ″ is formed by reversing the order of formation of the non-transmissive layer 2.

Referring to fig. 8, the polarizing film 40 may be configured such that the non-transmissive layer 2 "of the polarization splitting device 30 described above is upside down. In this way, the polarization splitting device 40 may be configured such that the high-reflectance portions 2A, the low-reflectance portions 2B, and the intermediate portions 2C of the non-transmissive layer 2 ″ of the polarization splitting device 30 according to the third exemplary embodiment are replaced with the high-reflectance portions 2A ', the low-reflectance portions 2B', and the intermediate portions 2C 'of the non-transmissive layer 2' ″ of the fourth exemplary embodiment. That is, the fourth exemplary embodiment may combine the order of the parts of the first exemplary embodiment with the varied material composition of the third exemplary embodiment.

The polarization splitting device 40 of the fourth exemplary embodiment may have the same operational effects as the second embodiment, and may have the base portion 1a provided at the rear surface of the grating portion 1b with respect to the outside such that the grating portion 1b faces the light source such as the BLU.

The polarization splitting device 40 may be manufactured by the manufacturing apparatus 110 shown in fig. 9 by reversing the conveyance direction of the transmission base member 1 by rotating the cooling drum 5 counterclockwise, or by reversing the positions of the high-reflectance material deposition source 15, the low-reflectance material deposition source 16, the deposition shield 12, and the shield plate 14 left/right.

Specific examples 1-4 of wire grid polarizers formed in accordance with the above-described exemplary embodiments will be described below in conjunction with comparisons 1 and 2.

Example 1

A polyethylene terephthalate (PET) film having a thickness of 100 μm is used as the transmission base member 1, and WGPs are manufactured as described above in connection with the first exemplary embodiment.

First, stripe-shaped gate portions 1b were formed on the transmission base member 1 at a gate pitch P of 150nm, a width W of 75nm, and a height of 150 nm. This shape of the gate portion 1b is also common to the following examples 2 to 4.

Aluminum is used as the deposition material 11, which is ejected from the deposition source 9 for deposition. Referring to fig. 5 and 6, the deposition angles θ 1, θ 2, θ 3, and θ 4 are set to-60 °, -30 °, -60 °, and-90 °, respectively. In the former stage of the deposition process, the high-reflectance part 2a is formed first, and the middle part 2c is formed, the composition of which gradually changes from the high-reflectance part 2a to the low-reflectance part 2b according to the change of the deposition angle. At the later stage of the deposition process, the low-reflectance part 2b is formed. The height of the non-transmissive layer 2 is 150 nm. As a result, a WGP of the polarization splitting device 10 such as shown in fig. 2 is manufactured.

When the WGP was used for the lower polarization film of an LCD device for an LCD television, a bright room (300Lx) contrast of 1000: 1 was measured.

Example 2

A Polycarbonate (PC) film having a thickness of 100 μm was used as the transmission base member 1, and WGPs were manufactured as described above in connection with the second exemplary embodiment. The pitch P, width W and height of the gate portion 1b are the same as those in example 1.

Aluminum is used as the deposition material 11, which is ejected from the deposition source 9. Referring to fig. 5 and 6, the deposition angles θ 1, θ 2, θ 3, and θ 4 are set to 90 °, 60 °, 30 °, and 60 °, respectively. In a previous stage of the deposition process, the low-reflectance part 2b 'is formed first, and then the middle part 2 c' is formed, the composition of which gradually changes from the low-reflectance part 2b 'to the high-reflectance part 2 a' according to the change of the deposition angle. At a later stage of the deposition process, the high-reflectance portions 2 a' are formed. The height of the non-transmissive layer 2' is 150 nm. As a result, a WGP of the polarization splitting device 20 such as shown in fig. 8 is manufactured.

When this up/down reversed WGP was used for the lower polarization film of an LCD device for an LCD television, a bright room (300Lx) contrast of 1000: 1 was measured.

Example 3

A PET film having a thickness of 100 μm is used as the transmission base member 1, and WGPs are manufactured as described above in connection with the third exemplary embodiment. The pitch P, width W and height of the gate portion 1b are the same as those in example 1.

Aluminum is used as the deposition material 17 ejected from the high-reflectance material deposition source 15, and carbon is used as the deposition material 18 ejected from the low-reflectance material deposition source 16. The deposition angles θ 1, θ 2, θ 3, and θ 4 are set to-60 °, -30 °, 60 °, and 90 °, respectively. In a former stage of the deposition process, the high-reflectance portion 2A made of aluminum is formed first, and then the middle portion 2C is formed, in which aluminum and carbon are mixed, and the composition ratio of the mixture is gradually changed from the high-reflectance portion 2A to the low-reflectance portion 2B. At the later stage of the deposition process, the low-reflectance portion 2B made of carbon is formed. The height of the non-transmissive layer 2 "is 150 nm. As a result, a WGP of the polarization splitting device 30 such as shown in fig. 2 is manufactured.

Example 4

A PC film having a thickness of 100 μm is used as the transmission base member 1, and WGPs are manufactured by an exemplary modified polarization beam splitting device manufacturing method according to the second embodiment of the present invention. The pitch P, width W and height of the gate portion 1b are the same as those in example 1.

In the manufacturing apparatus shown in fig. 9, the positions of the high-reflectance material deposition source 15 and the low-reflectance material deposition source 16 are exchanged so that the high-reflectance material 17 is deposited from the high-reflectance deposition source 15 after the low-reflectance material 18 is deposited from the low-reflectance deposition source 16. The deposition angles θ 1, θ 2, θ 3, and θ 4 are set to-60 °, -30 °, 60 °, and 90 °, respectively. Aluminum is used as the deposition material ejected from the high-reflectance material deposition source 15, and carbon is used as the deposition material ejected from the low-reflectance deposition source 16. In a previous stage of the deposition process, the low-reflectance part 2B 'made of carbon is first formed, and then the middle part 2 c' is formed, in which aluminum and carbon are mixed, and the composition ratio is gradually changed from the low-reflectance part 2B 'to the high-reflectance part 2A'. At a later stage of the deposition process, the high-reflectance portion 2A' made of aluminum is formed. The height of the non-transmissive layer 2 "' is 150 nm. As a result, a WGP of the polarization splitting device 40 such as shown in fig. 8 is manufactured.

Comparative example 1

Referring to fig. 10a, a PET film 50 having a thickness of 100 μm is used as a light-transmitting substrate, and the WGP shown in fig. 10a is manufactured according to the following process.

1. Aluminum and carbon each having a thickness of 100nm are deposited and overlapped on the surface of the PET film 50.

2. A resist is applied over the deposited layer and lines and spaces in the resist are formed by photolithography and etching.

3. The aluminum layer and the carbon layer are etched using the resist as a mask.

4. The resist remaining on the deposited layer is stripped off.

The WGP fabricated by the above process has a gate pitch P of 150nm and a gate width W of 75 nm. The total height of the gate is 200nm, the thickness of the aluminum layer 51 is 100nm, and the thickness of the carbon layer 52 is 100 nm.

Comparison 2

Referring to fig. 10b, a PET film 50 having a thickness of 100 μm is used as a light-transmitting substrate, and the WGP shown in fig. 10b is manufactured according to the following process:

1. an aluminum layer having a thickness of 150nm is deposited on the surface of the PET film 50.

2. A resist is applied over the deposited aluminum layer and lines and spaces in the resist are formed by photolithography and etching.

3. The aluminum layer is etched using the resist as a mask.

4. The resist remaining on the deposited layer is stripped off.

The gate of the aluminum layer 53 of the WGP manufactured by the above process has a gate pitch P of 150nm, a gate width W of 75nm, and a gate height of 150 nm.

When the WGP was used for the lower polarization film of an LCD device for an LCD television, a bright room (300Lx) contrast of 500: 1 was measured.

The evaluation results of the above examples 1 to 4 and comparative examples 1 and 2 are summarized in table 2 below.

TABLE 2

Contrast ratio

Height of grid

Grid strength

Manufacturing process

Example 1	1000∶1	150nm	In general	Is easy to use
					Example 2	1000∶1	150nm	In general	Is easy to use
Example 3	1000∶1	150nm	In general	Is easy to use
					Example 4	1000∶1	150nm	In general	Is easy to use
Comparative example 1	1000∶1	200nm	Weak (weak)	Difficulty in
					Comparison 2	500∶1	150nm	In general	In general

The WGPs of examples 1-4 can be more easily manufactured when compared to comparative 1, while exhibiting the same comparative performance as comparative 1. Also, the height of the deposition layer can be kept low, and the strength of the gate can be kept common by forming an intermediate gradation portion between the high-reflectance portion and the low-reflectance portion. Also, the WGPs of examples 1 to 4 can be more easily manufactured while exhibiting higher contrast ratio when compared with comparative example 2. In this way, the polarization beam splitting device according to embodiments of the present invention can be used as a reflection type polarization beam splitting element having a high contrast effect and performance.

As described above, the polarization splitting device, the display including the device, the method of manufacturing the device, and the apparatus for manufacturing the device may provide a device in which the deposition layer is formed on the gate part by changing the composition and/or structure of the deposition material such that the reflectance on the light incident side is high with respect to the incident light and the reflectance becomes relatively low in the transmission direction of the incident light. Accordingly, the polarization splitting device can exhibit a high contrast effect and the strength of the deposited layer can be enhanced, while improving the manufacturing efficiency and reliability even when a large-sized polarization splitting device is manufactured.

There have been disclosed herein exemplary embodiments of the invention and, although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purposes of limitation. For example, where the embodiments describe movement of a first member relative to a second member, it will be understood that such movement is relative and the second member may move relative to the first member, or both members may move.

In the above-described exemplary embodiments, two stages in which two holes may be formed corresponding to a single deposition source and a deposition sub-process may be performed by the single deposition source are explained. The deposition angle may be changed by the deposition angle determining means and the deposition layer may have a gradually changing reflectivity. However, it should be understood that the number of apertures corresponding to a single deposition source is not limited to two. For example, one aperture may be paired with one deposition source, multiple pairs of apertures and deposition sources may be provided, etc., depending on the amount of reflectivity desired.

The polarizing film manufacturing apparatus as described above may continuously convey a light transmissive substrate in a second direction by supporting a rear surface of a grating portion, wherein the grating portion of the light transmissive substrate has a pattern of small convexes and concaves extending in a first direction perpendicular to the second direction, and a deposition layer may be deposited on the conveyed light transmissive substrate. The manufacturing apparatus may include: at least one deposition source positionable opposite the light-transmissive substrate; and a deposition angle determining member which may be disposed between the deposition source and the base member, and which may have one or more holes for each deposition source along a conveying direction of the base member. With this manufacturing apparatus, the deposition process may be performed by changing the deposition angle with respect to the normal direction of the base member from a relatively small value to a relatively large value, or from a relatively large value to a relatively small value along the conveyance direction of the base member. Accordingly, a deposition layer in which the reflectivity gradually changes according to the change of the deposition angle may be formed. The optimum range of deposition angles may be determined based on the relationship between the reflectivity and the gate shape as described above.

Also, in the above description, it is explained that the polarization beam splitter manufacturing apparatus may include one or two deposition sources. However, it should be understood that the fabrication apparatus may have three or more deposition sources, which may be used to fabricate a polarization beam splitter device having a reflectivity that gradually varies within multiple layers.

Also, in the above description, it is explained that, for example, the mask plate is used, the center hole may be divided into the upstream-side hole and the downstream-side hole 12B so that the first and second deposition materials may be mixed in a desired ratio through the center hole, but it should be understood that the structure of the manufacturing apparatus may be modified so that the mask plate is omitted and the center hole is commonly used for both the high-reflection material deposition source and the low-reflection material deposition source.

Also, in the above description, it is explained that the transmission base member 1 may be conveyed along the outer surface of the cooling drum 5. However, it should be understood that the transfer path is not limited to a circumferential shape. The transfer path may be formed in a non-circular curved shape, a straight line shape, a dotted line shape, etc., and the deposition shield and the deposition source may be disposed on the transfer path.

Also, in the above description, it is explained that the deposition angle within the deposition material ejection range may be changed according to the movement of the transmission base member. However, it should be understood that the deposition angle may be changed by moving the deposition shield or the deposition source with respect to the transmissive base member, or by changing the ejection direction of the deposition material, or the like.

It will therefore be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as set forth in the following claims, including the various aspects of the exemplary embodiments described above.

Claims

1. A method for fabricating a polarization splitting device, comprising:

providing a transmissive base member having a pattern of ridges on a base; and is

Forming a non-transmissive layer on the ridge, wherein the non-transmissive layer includes:

a light reflecting portion, and

a light absorbing part, and

at an intermediate portion between the light reflecting portion and the light absorbing portion,

the light reflecting portion and the light absorbing portion have the same material composition, and

wherein forming the non-transmissive layer includes depositing the non-transmissive layer by changing a deposition angle according to the non-transmissive layer height,

wherein the non-transmissive layer exhibits a gradual change in reflectivity having a dense state of reflection and a loose state of absorption,

wherein,

forming the non-transmissive layer includes applying the material composition from at least two different angles relative to the base,

a first angle of the at least two angles corresponds to the light reflecting portion, and

a second angle of the at least two angles corresponds to the light absorbing portion; and

forming the non-transmissive layer includes applying the material composition from at least two different ranges of angles,

a first range of the at least two ranges corresponds to the light reflecting portion, and

a second range of the at least two ranges corresponds to the light absorbing portion; and

a deposition angle thetaH in a deposition sub-process of forming the light reflecting portion has a range of theta 2 ≦ thetaH ≦ theta 1, where theta 2 < theta 1, the deposition angle thetaH being an angle with respect to a normal to a deposition surface,

the deposition angle thetaL in the deposition sub-process of forming the light absorbing part has a range of theta 3 ≦ thetaL ≦ theta 4, where theta 3 < theta 4, the deposition angle thetaL being an angle with respect to a normal to a deposition surface, and

θ 1, θ 2, θ 3, and θ 4 satisfy the following conditions:

40°≤θ1≤70°，

20°≤θ2≤50°，

theta 3 is more than or equal to 60 degrees and less than 90 degrees

60°≤θ4＜90°。

2. The method of claim 1, wherein the method comprises:

crossing the transmissive base member across a first aperture in a first direction approximately perpendicular to a direction of extension of the ridge and depositing material on the ridge through the first aperture to form the light reflective portion; and is

The transmissive base member is passed across a second aperture in the first direction, and a material is deposited on the light reflecting portion through the second aperture to form the light absorbing portion.

3. The method of claim 1, wherein the method comprises:

crossing the transmissive base member across a first hole in a first direction approximately perpendicular to an extending direction of the ridge and depositing a material on the ridge through the first hole to form the light absorbing part; and is

The transmissive base member is passed across a second aperture in the first direction, and a material is deposited on the light absorbing portion through the second aperture to form the light reflecting portion.