Patent Description:
The present application relates to a substrate.

An optical device capable of adjusting transmittance or color of light by disposing a light modulation layer between two substrates is known. For example, in Patent Document <NUM>, a so-called GH cell (guest host cell) to which a mixture of a liquid crystal host and a dichroic dye guest is applied is known.

In such a device, so-called spacers are located between the substrates to maintain the spacing between the two substrates.

<CIT> describes a stereoscopic image display apparatus, including a display panel including pixels arranged in row and column directions and displaying an image using a light. A switching panel, which controls liquid crystal molecules to allow the image displayed on the display panel to be recognized as a two or three-dimensional image, is disposed on the display panel. The switching panel includes a first substrate, a second substrate facing the first substrate while being coupled to the first substrate, and spacers interposed between the first and second substrates. Each pixel has a first width in the row direction and has a second width in the column direction, and the spacers are arranged in the row direction at a first distance and arranged in the column direction at a second distance. The first distance is different from the first width, and the second width is different from the second distance.

<CIT> describes a display device including a display section and a light barrier element. The light barrier element includes a pair of substrates, a liquid crystal layer that is provided between the pair of substrates and has a plurality of sub-regions that transmit or block light, and a plurality of spacers provided between the pair of substrates. The plurality of spacers are randomly arranged in part or all of a region in surfaces of the substrates.

<CIT> and <CIT> describe a light-modulating cell, comprising a pair of polarizing plates (a first polarizing plate and second polarizing plate), a pair of electrodes (a first transparent electrode and second transparent electrode) disposed between the pair of polarizing plates (the first polarizing plate and second polarizing plate) and a pair of orientation films (a first orientation film and second orientation film) disposed between the pair of electrodes (the first transparent electrode and second transparent electrode). Multiple spacers are disposed, the spacers supporting at least one of the pair of orientation films and making two-dimensional contact with at least one of the pair of orientation films. For at least a portion of the plurality of spacers, the distance therefrom to the nearest other spacers is not uniform.

The present application relates to a substrate, for example, a substrate comprising spacers. In the present application, it is one object to provide a substrate on which spacers can be irregularly disposed while having regularity and irregularity simultaneously to provide an optical device that a so-called moire phenomenon or the like does not occur and uniform optical characteristics are exhibited in all regions.

Among physical properties mentioned in this specification, when the measured temperature affects the results, the relevant physical properties are physical properties measured at room temperature, unless otherwise specified. The term room temperature is a natural temperature without being heated or cooled, which may be, for example, any temperature in a range of <NUM> to <NUM>, or about <NUM> or about <NUM> or so. In addition, unless otherwise specified herein, the unit of temperature is °C.

Among physical properties mentioned in this specification, when the measured pressure affects the results, the relevant physical properties are physical properties measured at room pressure, unless otherwise specified. The term normal pressure is a natural pressure without being pressurized or depressurized, where usually about <NUM> atm is referred to as the normal pressure.

The substrate of the present application comprises a base layer and spacers present on the base layer. The substrate according to the claimed invention is defined in appended independent claim <NUM> or appended independent claim <NUM>.

As the base layer, any base layer used in a substrate in a configuration of a known optical device such as, for example, an LCD (liquid crystal display) can be applied without particular limitation. For example, the base layer may be an inorganic base layer or an organic base layer. As the inorganic base layer, a glass base layer or the like can be exemplified, and as the organic base layer, various plastic films or the like can be exemplified. The plastic film can be exemplified by a TAC (triacetyl cellulose) film; a COP (cycloolefin copolymer) film such as a norbornene derivative; an acrylic film such as PMMA (poly(methyl methacrylate); a PC (polycarbonate) film; a polyolefin film such as PE (polyethylene) or PP (polypropylene); a PVA (polyvinyl alcohol) film; a DAC (diacetyl cellulose) film; a Pac (polyacrylate) film; a PES (polyether sulfone) film; a PEEK (polyetheretherketone) film; a PPS (polyphenylsulfone) film, a PEI (polyetherimide) film; a PEN (polyethylenemaphthatate) film; a PET (polyethyleneterephtalate) film; a PI (polyimide) film; a PSF (polysulfone) film or a PAR (polyarylate) film, and the like, but is not limited thereto.

In the substrate of the present application, the thickness of the base layer is also not particularly limited, where an appropriate range may be selected depending on applications.

In the substrate of the present application, a plurality of spacers is present on the base layer. The spacer may be fixed to the base layer. In this case, the spacer may be fixed directly in contact with the base layer, or if there are other layers between the base layer and the spacer, it may be fixed on the relevant other layer. The kind of the other layer includes a known layer necessary for driving the optical device, and for example, there is an electrode layer to be described below.

The plurality of spacers is disposed on the base layer while having predetermined regularity and irregularity simultaneously. Specifically, at least a part of the plurality of spacers on the base layer are in an irregular arrangement in terms of being arranged so as to have pitches different from each other, but are regular in terms of being arranged with substantially the same density between regions determined according to a predetermined rule.

As described above, in the substrate of the present application, at least a part of the spacers disposed on the base layer are disposed so as to have pitches different from each other.

Here, when a part of the plurality of spacers have been selected so as to form a closed figure in a state where other spacers are not present therein, the term pitch can be defined as a length of a side of the closed figure. In addition, unless otherwise specified, the unit of the pitch is µm.

In one example, the length of the side of the closed figure is at most <NUM> or so. In another example, the maximum length of the lengths of the sides of the closed figure may be about <NUM> or less, about <NUM> or less, about <NUM> or less, or about <NUM> or less, or may be about <NUM> or more, <NUM> or more, or <NUM> or more.

In addition, the minimum length of the lengths of the sides of the closed figure may be about <NUM> or more. In another example, the minimum length of the lengths of the sides of the closed figure may be about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, or about <NUM> or less, or may be about <NUM> or more, <NUM> or more, or <NUM> or more.

When the substrate of the present application has been applied to a product through the above spacing arrangement, a cell gap of the element can be stably maintained and it can be prevented to cause appearance defects such as stains.

The maximum or minimum length can be obtained by using a known random number coordinate program, for example, a CAD, MATLAB or STELLA random number coordinate program or the like.

The closed figure thus formed is a triangle, a quadrangle or a hexagon. That is, when three spacers among the plurality of spacers have been optionally selected and connected to each other, the triangle is formed; when four spacers have been selected and connected to each other, the quadrangle is formed; and when six spacers have been selected and connected, the hexagon is formed.

<FIG> is an example of a quadrangle which is a closed figure formed by optionally selecting four spacers among the spacers (black dots) existing on the base layer and connecting them by imaginary lines (dotted lines). However, upon determining the pitch, the closed figure thus formed is formed such that no spacer is present therein. Therefore, for example, in the case where spacers are formed such that another spacer is present therein, as in <FIG>, they are excluded when determining the pitch.

In one example, the ratio (%) of the number of sides having the same length among sides of a triangle, a quadrangle or a hexagon, which is a closed figure thus formed (<NUM> × (number of sides of the same length)/<NUM> in the case of a triangle, <NUM> × (number of sides of the same length)/<NUM> in the case of a hexagon, and <NUM> × (number of sides of the same length)/<NUM> in the case of a hexagon) can be <NUM>% or less. In another example, the ratio may be <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, or <NUM>% or less. The lower limit of the ratio is not particularly limited. That is, in some cases, since the lengths of all sides of the closed figure may not be the same, the lower limit of the ratio may be <NUM>%.

As described above, the arrangement of the spacers of the present application is irregular in that at least a part thereof has different pitches, but such irregularity is controlled under certain regularity. Here, the regularity may mean that the arrangement density of spacers is substantially close to each other between certain regions.

According to one aspect of the claimed invention, if the normal pitch of the plurality of irregularly arranged spacers is P, when two or more square regions with 10P as a length of one side have been optionally selected on the surface of the base layer, the standard deviation of the number of spacers present in each square region is <NUM> or less.

<FIG> is a view exemplarily showing a case where four square regions (dotted rectangular regions in <FIG>) with 10P as the length of one side are optionally selected.

Here, the term normal pitch means a distance between the centers of adjacent spacers in a state where the plurality of spacers, in actuality, irregularly disposed on the base layer are placed so that all of the spacers are virtually disposed at the same pitch in consideration of the number of the spacers and the area of the base layer.

The manner to confirm a virtual state where all of the above-mentioned spacers are disposed so as to have the same pitch is known, which can be achieved by using a random number generating program such as, for example, CAD, MATLAB, STELLA or Excel.

The standard deviation is a numerical value representing a degree of scattering of the number of the spacers, which is a numerical value determined by a positive square root of dispersion.

That is, when at least two or more of the rectangular regions have been optionally designated on the surface of the base layer that spacers are formed thereon and then the standard deviation of the numbers of spacers existing in the regions has been obtained, the standard deviation is <NUM> or less. In another example, the standard deviation may be <NUM> or less, <NUM> or less, or <NUM> or less. In addition, the standard deviation means that the lower the numerical value is, the desired regularity is achieved, and thus the lower limit is not particularly limited, which may be <NUM>, for example.

Here, the number of the designated rectangular regions is not particularly limited as long as it is <NUM> or more, but in one example, it may be selected as the number that the rectangular regions are optionally selected so as not to overlap each other on the surface of the base layer, provided that the area occupied by the optionally selected regions is about <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, or <NUM>% or more of the total area of the base layer.

The range of the normal pitch (P) forming one side of the arbitrary rectangular region can be determined by the number of spacers present on the base layer and the area of the relevant base layer, as described above, which is not particularly limited, and usually, it may be in a range of <NUM> to <NUM>,<NUM>. In another example, the normal pitch (P) may be about <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, or <NUM> or more, and may also be about <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, or <NUM> or less.

Although not particularly limited, the average number of spacers present in optionally selected square regions as above may be, for example, about <NUM> to <NUM> or so. In another example, the average number may be <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, or <NUM> or more. Also, in another example, the average number may be <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, or <NUM> or less.

The ratio (SD/A) of the average number (A) of the spacers and the above-mentioned standard deviation (SD) is <NUM> or less. In another example, the ratio may be <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, or <NUM> or less. The ratio (SD/A) is <NUM> or more.

The average number (A) or the ratio (SD/A) may be optionally changed, and for example, the numerical value may be changed in consideration of the transmittance, the cell gap and/or the uniformity of the cell gap required in the device to which the substrate is applied, and the like.

In another example, when the surface of the base layer on which the irregularly disposed spacers are formed has been divided into two or more regions having the same area, the standard deviation of the number of the spacers in each unit region may be <NUM> or less.

Here, the meaning of the standard deviation and the specific examples thereof are as described above.

That is, in another aspect of the claimed invention, when the base layer has been divided into at least two regions having the same area and the standard deviation of the number of the spacers present in each divided unit region has been obtained, the standard deviation thereof is <NUM> to <NUM>. In this case, the shape of each divided unit region is not particularly limited as long as the relevant unit regions are divided so as to have the same area, but it may be, for example, a triangular, square, or hexagonal region. In addition, in another example, the standard deviation in the above state may be <NUM> or less, <NUM> or less, or <NUM> or more, <NUM> or more, or <NUM> or more.

Here, the number of unit regions is not particularly limited, but in one example, the base layer may be divided into two or more, four or more, six or more, eight or more, or ten or more regions having the same area. Here, since it means that the higher the number of the divided regions, the more uniform the density of the spacers is maintained, the upper limit of the number of divided regions is not particularly limited.

When the virtual square region with P, which is a normal pitch, as one side has been selected on the substrate on which the plurality of spacers are disposed so as to have regularity and irregularity simultaneously, the average number of spacers existing in the relevant region may be in a range of <NUM> to <NUM>. In another example, the average number may be <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, or <NUM> or less. Also, in another example, the average number may be <NUM> or more. Here, the number of square regions of which the length of one side is optionally designated as the normal pitch (P) is not particularly limited as long as it is two or more, but in one example, it may be selected as the number that the square regions are optionally selected so as not to overlap each other on the surface of the base layer, provided that the area occupied by the optionally selected region is about <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, or <NUM>% or more of the total area of the base layer.

The entire density of the plurality of spacers can be adjusted so that the ratio of the area occupied by the spacers is about <NUM>% or less relative to the total area of the base layer. In another example, the ratio may be about <NUM>% or less, about <NUM>% or less, about <NUM>% or less, about <NUM>% or less, about <NUM>% or less, about <NUM>% or less, about <NUM>% or less, about <NUM>% or less, about <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, <NUM>% or less, or <NUM>% or less. In another example, the ratio may be about <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, or <NUM>% or more.

When an optical device has been implemented by disposing a plurality of spacers on the base layer in the above form, the uniform optical characteristics can be ensured without causing the so-called moire phenomenon, while the spacers maintain the uniform pitch (cell gap) between the substrates.

The respective numerical values may be changed, if necessary, and for example, the numerical values may be changed in consideration of the transmittance, the cell gap and/or the uniformity of the cell gap required in the device to which the substrate is applied, and the like.

The plurality of spacers may be arranged such that their spacing normal distribution diagram represents a predetermined shape.

Here, the spacing normal distribution diagram is a distribution diagram showing the pitch between the spacers as the X-axis and the ratio of the spacers having the relevant pitch among all the spacers as the Y-axis, where the ratio of the spacers is a ratio obtained when the number of the entire spacer has been assumed to be <NUM>.

An example of such a distribution diagram is shown in <FIG>. The pitch in the description related to the spacing normal distribution diagram herein is also a length of sides in a triangle, a quadrangle or a hexagon, which is the above-mentioned closed figure.

The distribution diagram can be obtained using a known random number coordinate program, for example, a CAD, MATLAB or STELLA random number coordinate program or the like.

According to the claimed invention, the plurality of spacers is disposed such that a half height area in the distribution diagram is in a range of <NUM> to <NUM>. In another example, the half height area may be <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, or <NUM> or more. Also, in another example, the half height area may be <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, or <NUM> or less.

The plurality of spacers may be arranged such that a ratio (FWHM/Pm) of the half height width (FWHM) to the average pitch (Pm) in the distribution diagram is <NUM> or less. In another example, the ratio (FWHM/Pm) may be <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, or <NUM> or more. Also, in another example, the ratio (FWHM/Pm) is about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, or about <NUM> or less.

When at least <NUM>% or more, <NUM>% or more, <NUM>% or more, or <NUM>% or more of spacers have been selected to form a triangle, quadrangle or hexagon, which is the above-described closed figure, the above-mentioned average pitch (Pm) is an average of the lengths of the respective sides of the triangle, quadrangle or hexagon formed by the selected spacers. Here, the spacers are also selected so that the formed triangles, quadrangles or hexagons do not share vertexes with respect to each other.

The plurality of spacers is disposed such that the half height width (FWHM) in the distribution diagram is in a range of <NUM> to <NUM>,<NUM>. In another example, the half height width (FWHM) may be about <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, <NUM> or more, or <NUM> or more. In another example, the half height width (FWHM) may be about <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, <NUM> or less, or <NUM> or less.

The plurality of spacers may be disposed such that the maximum height (Fmax) of the spacing normal distribution diagram is <NUM> or more and less than <NUM>. In another example, the maximum height (Fmax) may be about <NUM> or more, about <NUM> or more, about <NUM> or more, or about <NUM> or more, about <NUM> or more, or about <NUM> or more. Also, in another example, the maximum height (Fmax) may be about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, about <NUM> or less, or about <NUM> or less.

When an optical device has been implemented by disposing a plurality of spacers on to have the spacing normal distribution diagram in such a form, the uniform optical characteristics can be ensured without causing the so-called moire phenomenon, while the spacers maintain the uniform pitch (cell gap) between the substrates.

The concept of degree of irregularity is introduced for a plurality of spacers to be disposed so as to simultaneously have irregularity and regularity as above. Hereinafter, a method for designing the arrangement of the spacers having such a form will be described.

In order to achieve the arrangement of the spacers having the above-mentioned regularity and irregularity simultaneously, a step of starting from a normal arrangement state and relocating the spacers to have irregularity is performed.

Here, the normal arrangement state is a state where the plurality of spacers are disposed on the base layer such that a regular triangle, a square or a regular hexagon in which all sides have the same length can be formed. <FIG> is a state in which spacers are disposed to form the square as an example. The length P of one side of the square in this state may be equal to the above-mentioned normal pitch. In such an arrangement state, a circle region having a radius of a length proportional to the length P of one side is designated on the basis of a point where one spacer exists, and the program is set so that the one spacer can be randomly moved in the region. For example, <FIG> schematically shows a form in which the circle region having the radius of the length of <NUM>% (<NUM>. 5P) relative to the length P is set and the spacer moves to any point in the region. The above-described arrangement can be achieved by applying such a movement to spacers of at least <NUM>% or more, <NUM>% or more, <NUM>% or more, <NUM>% or more, or <NUM>% (all spacers).

In such a design method, the ratio for the length P which becomes the radius of the circle region may be defined as a degree of irregularity. For example, in the case shown in <FIG>, the degree of irregularity is about <NUM>%.

In one example, the degree of irregularity in the design manner may be about <NUM>% or more, about <NUM>% or more, about <NUM>% or more, about <NUM>% or more, about <NUM>% or more, about <NUM>% or more, about <NUM>% or more, about <NUM>% or more, about <NUM>% or more, about <NUM>% or more, about <NUM>% or more, about <NUM>% or more, or about <NUM>% or more. In one example, the degree of irregularity may be about <NUM>% or less, about <NUM>% or less, about <NUM>% or less, or about <NUM>% or less.

The arrangement having the above-described irregularity and regularity simultaneously can be achieved by designing the arrangement of the spacers in the same manner as above and forming the spacers according to the designed arrangement.

Here, although the case where the normal state starts from the square has been exemplified, the normal state may be other figures such as a regular triangle or a regular hexagon, and in this case, the above-described arrangement can also be achieved.

The means for designing the arrangement of the spacers in the same manner as above is not particularly limited, and a known random number coordinate program such as, for example, a CAD, MATLAB, STELLA or Excel random number coordinate program can be used.

For example, after the arrangement of the spacers is first designed in the same manner as above, a mask having a pattern according to the relevant design and the like may be manufactured and such spacers may be implemented by a lithography or imprinting method and the like using the relevant mask.

The dimension of such spacers is not particularly limited, which may be selected within a known range. For example, the spacers may have a bottom cross-sectional area in a range of about <NUM><NUM> to <NUM><NUM>, and a height in a range of about <NUM> to <NUM>. In another example, the bottom cross-sectional area may be about <NUM><NUM> or more, <NUM><NUM> or more, <NUM><NUM> or more, <NUM><NUM> or more, <NUM><NUM> or more, <NUM><NUM> or or more, or <NUM><NUM> or more, or may also be <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, <NUM><NUM> or less, or <NUM><NUM> or less.

The spacer can be formed using a known material and method. In one example, the spacer may be formed by comprising an ultraviolet curable resin. For example, the spacer can be formed by designing the regular irregularity in the above-described manner and curing an ultraviolet curable compound according to the desired arrangement in an imprinting or lithography method using a mask designed according to the designed contents, where the ultraviolet curable resin that is a cured product of the ultraviolet curable compound can form the spacer. The specific kind of the ultraviolet curable compound that can be used for forming the spacer is not particularly limited, and for example, an acrylate-based polymer or an epoxy-based polymer, and the like may be used, without being limited thereto.

The substrate of the present application may comprise, in addition to the base layer and the spacers, other elements required for driving the optical device. These elements are variously known, and typically, there is an electrode layer. In one example, the substrate may further comprise an electrode layer between the base layer and the spacers. As the electrode layer, a known material can be applied. For example, the electrode layer may comprise a metal alloy, an electrically conductive compound or a mixture of two or more thereof. Such a material can be exemplified by a metal such as gold, CuI, an oxide material such as ITO (indium tin oxide), IZO (indium zinc oxide), ZTO (zinc tin oxide), zinc oxide doped with aluminum or indium, magnesium indium oxide, nickel tungsten oxide, ZnO, SnO<NUM> or In<NUM>O<NUM>, a metal nitride such as gallium nitride, a metal selenide such as zinc selenide, a metal sulfide such as zinc sulfide, or the like. A transparent positive hole injecting electrode layer can also be formed by using a laminate of a metal thin film of Au, Ag or Cu, and the like, and a transparent material having high refractive index such as ZnS, TiO<NUM> or ITO.

The electrode layer may be formed by any means such as vapor deposition, sputtering, chemical vapor deposition or electrochemical means. Patterning of the electrode layer is also possible in a known manner without any particular limitation, and the electrode layer may be patterned, for example, through known photolithography or a process using a shadow mask or the like.

The substrate of the present application may further comprise an alignment film present on the base layer and the spacers.

Here, the kind of the alignment film formed on the base layer and the spacers is not particularly limited, where a known alignment film, for example, a known rubbing alignment film or a photo-alignment film can be applied.

A method of forming the alignment film on the base layer and the spacers and performing orientation treatment thereon is also in accordance with a known method.

The present application also relates to an optical device formed using such a substrate.

An exemplary optical device of the present application may comprise the substrate and a second substrate disposed opposite to the substrate and maintaining a gap with the substrate by the spacers in the substrate.

In the optical device, a light modulation layer may be present in a gap between two substrates. In the present application, the term light modulation layer may include all known types of layers capable of changing at least one characteristic among characteristics such as polarization states, transmittance, color tones and reflectance of incident light depending on purposes.

For example, the light modulation layer is a layer comprising a liquid crystal material, which may be a liquid crystal layer switched between a diffusion mode and a transparent mode by on-off of a voltage, for example, a vertical electric field or a horizontal electric field, a liquid crystal layer switched between a transparent mode and a blocking mode, a liquid crystal layer switched between a transparent mode and a color mode, or a liquid crystal layer switched between color modes of different colors.

Light modulation layers, for example, liquid crystal layers, capable of performing the above action are variously known. One exemplary light modulation layer is a liquid crystal layer used in a typical liquid crystal display. In another example, the light modulation layer may also be various types of so-called guest host liquid crystal layers, polymer dispersed liquid crystal layers, pixel-isolated liquid crystal layers, suspended particle devices or electrochromic devices, and the like.

The polymer dispersed liquid crystal layer (PDLC) is a superordinate concept including a PILC (pixel isolated liquid crystal), a PDLC (polymer dispersed liquid crystal), a PNLC (polymer network liquid crystal) or a PSLC (polymer stabilized liquid crystal), and the like. The polymer dispersed liquid crystal layer (PDLC) may comprise, for example, a liquid crystal region containing a polymer network and a liquid crystal compound dispersed in a state of being phase-separated from the polymer network.

The implementation manner or form of the light modulation layer is not particularly limited, and any known method may be employed without any limitations depending on purposes.

In addition, the optical device may further comprise additional known functional layers, such as a polarizing layer, a hard coating layer, and/or an antireflection layer, if necessary.

The present application relates to a substrate on which spacers are disposed in a certain arrangement state and an optical device using such a substrate. In the present application, a plurality of spacers are irregularly disposed on a substrate depending on a predetermined rule, so that overall uniform optical characteristics can be ensured without causing a so-called moire phenomenon or the like, while the spacers maintain the uniform cell gap in the construction of the optical device.

Hereinafter, the present application will be specifically described by way of examples, but the scope of the present application is not limited by the following examples.

A spacer arrangement pattern with a degree of irregularity of about <NUM>% was designed using a random number coordinate generating program (CAD) in the following manner. First, a state where <NUM> spacers were disposed on a base layer having a total area of about <NUM> at a constant interval (normal pitch) of <NUM> was assumed, as shown in <FIG> (normal arrangement state). At this time, the cross-sectional area of the bottom of the individual spacers was about <NUM> and the height was about <NUM>. Then, in a square formed by selecting four spacers as in <FIG>, a program was set so that individual spacers were randomly moved in a circle region having a radius (<NUM> P) of <NUM>% of the normal pitch, based on each spacer, and the individual spacers were moved to form a spacer arrangement pattern. <FIG> is an example of a spacer arrangement designed as above. As shown in <FIG>, when four spacers were selected so that a quadrangle as a closed figure was formed in the arrangement of the spacers and the length of each side was measured, at least one of the lengths of the sides of the quadrangle was different. In addition, the minimum length of all the side lengths of the quadrangle as the closed figure was about <NUM>, and the maximum length was about <NUM>. In <FIG>, when <NUM> square regions having a length of <NUM> times (10P) of the normal pitch (P) as one side were selected so that the regions did not overlap each other, the average number of spacers in each square region was <NUM> and the standard deviation was about <NUM>. Furthermore, when the surface of the base layer shown in <FIG> was divided into four rectangular regions having the same area, the average number of spacers in each rectangular region was <NUM> and the standard deviation was about <NUM>. <FIG> was a spacing normal distribution diagram of the spacers having the same arrangement as above, where the half height area in the distribution diagram was about <NUM>, the half height width (FWHM) was about <NUM>, the average pitch (Pm) was about <NUM>, and the maximum height (Fmax) was about <NUM>.

As the base layer (<NUM> in <FIG>), a base layer was used, in which a crystalline ITO (indium tin oxide) layer as an electrode layer was formed on a PC (polycarbonate) film. Although spacers were formed on the base layer in accordance with a conventional method of forming column spacers, the substrate was produced by forming spacers so that the arrangement followed the designed manner. The occurrence of the moire phenomenon was evaluated by a method of placing the substrate thus produced on a general commercial monitor. <FIG> is a result of confirming whether or not the moire phenomenon evaluated in the above method occurs, and <FIG> is a result of measurement with respect to the substrate on which spacers are formed according to the above-mentioned normal arrangement state. It can be confirmed from the results of <FIG> and <FIG> that the occurrence of the moire phenomenon can be suppressed by controlling the arrangement state of the spacers.

The spacer arrangement was designed in the same manner as in Example <NUM>, provided that the spacer arrangement was designed so that the degree of irregularity was <NUM>% (the program was set so that the individual spacers were randomly moved in a circle region having a radius (<NUM>. 5P) of <NUM>% of the normal pitch and the individual spacers were moved). In addition, the minimum length of all the sides of the quadrangle as the closed figure was about <NUM>, and the maximum length was about <NUM>.

<FIG> is an example of a spacer arrangement designed as above. As shown in <FIG>, when four spacers were selected so that a quadrangle as a closed figure was formed in the arrangement of the spacers and the length of each side was measured, at least one of the lengths of the sides of the quadrangle was different. In addition, in <FIG>, when <NUM> square regions having a length of <NUM> times (10P) of the normal pitch (P) as one side were selected so that the regions did not overlap each other, the average number of spacers in each square region was <NUM> and the standard deviation was about <NUM>. Furthermore, when the surface of the base layer shown in <FIG> was divided into four rectangular regions having the same area, the average number of spacers in each rectangular region was <NUM> and the standard deviation was about <NUM>. <FIG> was a spacing normal distribution diagram of the spacers having the same arrangement as above, where the half height area in the distribution diagram was about <NUM>, the half height width (FWHM) was about <NUM>, the average pitch (Pm) was about <NUM>, and the maximum height (Fmax) was about <NUM>.

<FIG> is a result of evaluating whether or not the moire phenomenon occurs in the same manner as in Example <NUM>, using the substrate formed in the above manner, and it can be confirmed that the occurrence of the moire phenomenon is suppressed as in Example <NUM>.

The spacer arrangement was designed in the same manner as in Example <NUM>, provided that the spacer arrangement was designed so that the degree of irregularity was <NUM>% (the program was set so that the individual spacers were randomly moved in a circle region having a radius (<NUM>. 7P) of <NUM>% of the normal pitch and the individual spacers were moved). In addition, the minimum length of all the sides of the quadrangle as the closed figure was about <NUM>, and the maximum length was about <NUM>.

<FIG> is a photograph evaluating whether or not appearance defects occur in the same manner as in Example <NUM> with respect to Example <NUM>.

The spacer arrangement designed as above was approximately similar to that shown in <FIG>. That is, as shown in <FIG>, even in the case of Example <NUM>, when four spacers were selected so that a quadrangle as a closed figure was formed in the arrangement of the spacers and the length of each side was measured, at least one of the lengths of the sides of the quadrangle was different. In addition, in the form as shown in <FIG>, when <NUM> square regions having a length of <NUM> times (10P) of the normal pitch (P) as one side were selected so that the regions did not overlap each other, the average number of spacers in each square region was <NUM> and the standard deviation was about <NUM>. Furthermore, when the surface of the base layer shown in <FIG> was divided into four rectangular regions having the same area, the average number of spacers in each rectangular region was <NUM> and the standard deviation was about <NUM>. <FIG> was a spacing normal distribution diagram of the spacers having the same arrangement as above, where the half height area in the distribution diagram was about <NUM>, the half height width (FWHM) was about <NUM>, the average pitch (Pm) was about <NUM>, and the maximum height (Fmax) was about <NUM>.

The spacer arrangement designed as above was approximately similar to that shown in <FIG>. That is, as shown in <FIG>, even in the case of Comparative Example <NUM>, when four spacers were selected so that a quadrangle as a closed figure was formed in the arrangement of the spacers and the length of each side was measured, at least one of the lengths of the sides of the quadrangle was different. In addition, when <NUM> square regions having a length of <NUM> times (10P) of the normal pitch (P) as one side were selected so that the regions did not overlap each other, the average number of spacers in each square region was <NUM> and the standard deviation was about <NUM>. Furthermore, when the surface of the base layer shown in <FIG> was divided into four rectangular regions having the same area, the average number of spacers in each rectangular region was <NUM> and the standard deviation was about <NUM>.

<FIG> is a photograph evaluating whether or not appearance defects occur in the same manner as in Example <NUM> with respect to Comparative Example <NUM>, and it can be confirmed from the drawing that defects in appearance are largely generated.

The spacer arrangement designed as above was approximately similar to that shown in <FIG>. That is, as shown in <FIG>, even in the case of Comparative Example <NUM>, when four spacers were selected so that a quadrangle as a closed figure was formed in the arrangement of the spacers and the length of each side was measured, at least one of the lengths of the sides of the quadrangle was different. In addition, when <NUM> square regions having a length of <NUM> times (10P) of the normal pitch (P) as one side were selected so that the regions did not overlap each other, the average number of spacers in each square region was <NUM> and the standard deviation was about <NUM>. Furthermore, when the surface of the base layer shown in Figure <NUM> was divided into four rectangular regions having the same area, the average number of spacers in each rectangular region was <NUM> and the standard deviation was about <NUM>.

The spacer arrangement designed as above was approximately similar to that shown in <FIG>. That is, as shown in <FIG>, even in the case of Comparative Example <NUM>, when four spacers were selected so that a quadrangle as a closed figure was formed in the arrangement of the spacers and the length of each side was measured, at least one of the lengths of the sides of the quadrangle differed. In addition, in Figure <NUM>, when <NUM> square regions having a length of <NUM> times (10P) of the normal pitch (P) as one side were selected so that the regions did not overlap each other, the average number of spacers in each square region was <NUM> and the standard deviation was about <NUM>. Furthermore, when the surface of the base layer shown in Figure <NUM> was divided into four rectangular regions having the same area, the average number of spacers in each rectangular region was <NUM> and the standard deviation was about <NUM>.

Claim 1:
A substrate for an optical device comprising a base layer; and a plurality of spacers present on the base layer,
wherein three, four or six spacers of the plurality of spacers are randomly selected, provided that when the selected spacers have been selected to form a triangle, a quadrangle or a hexagon, which is a closed figure, that other spacers are not present therein, the spacers are disposed so that at least one of the lengths of the sides in the triangle, the quadrangle or the hexagon differs,
characterized in that
when a normal pitch of the plurality of spacers is P, a standard deviation of the numbers of the spacers in a square region having 10P as one side length is <NUM> or less,
wherein the normal pitch is a distance between the centers of adjacent spacers in a state where the plurality of spacers, in actuality, irregularly disposed on the base layer are placed so that all of the spacers are virtually disposed at the same pitch in consideration of the number of the spacers and the area of the base layer,
wherein the maximum length of the lengths of the sides in the triangular, the quadrangle or the hexagon is <NUM> or less,
wherein a ratio of the standard deviation to an average number of spacers in said square region is <NUM> to <NUM>,
wherein the plurality of spacers is arranged such that a normalized area of a spacing normal distribution diagram of the plurality of spacers below half maximum height is in a range of <NUM> to <NUM> and a half height width (FWHM) in the spacing normal distribution diagram is <NUM> to <NUM>, and
wherein the spacing normal distribution diagram is a distribution diagram showing the pitch between the spacers as the X-axis and the ratio of the spacers having the relevant pitch among all the spacers as the Y-axis, where the ratio of the spacers is a ratio obtained when the number of the entire spacer has been assumed to be <NUM>.