KR20210122827A - Organic EL image display device and manufacturing method thereof - Google Patents

Abstract

According to the present invention, a reflective layer, an organic electroluminescent layer group, a polarization separation layer, and a circularly polarizing plate are arranged in this order, and the polarization separation layer is formed in a pattern corresponding to at least a part of the organic electroluminescent layer of the organic electroluminescent layer group. An organic EL image display device comprising a polarization separation portion disposed, wherein the rate of position shift between the polarization separation portion and the organic electroluminescent layer corresponding to the polarization separation portion is 10% or less in the entire area of the screen, and a liquid crystal composition After laminating the formed layer to face the organic electroluminescent layer group, there is provided a method of manufacturing the organic EL image display device comprising curing the layer formed of the liquid crystal composition to form the polarization separation portion. The organic EL image display device of the present invention has a high utilization efficiency of light emission from the organic electroluminescent layer group and a high luminance over the entire screen.

Description

Organic EL image display device and manufacturing method thereof

The present invention relates to an organic EL image display device and a method for manufacturing the same.

In an organic EL image display device (“organic electroluminescence image display device”, hereinafter sometimes simply referred to as “image display device”) that forms an image based on light emission from an organic electroluminescent layer group, surface reflection of external light It is common to dispose a circularly polarizing plate composed of a retardation layer and a polarizing layer in order to reduce and improve contrast. In this configuration, since more than half of the light emitted from the organic electroluminescent layer group is absorbed by the circularly polarizing plate, it has been conventionally proposed to provide a polarization separating means between the organic electroluminescent layer group and the circularly polarizing plate. As a polarization separating means, light passing through the circular polarizing plate is transmitted, and the polarized light absorbed by the circular polarizing plate is reflected and specularly reflected by the reflective layer in the light emitting element substrate, so that the light utilization efficiency is increased and the luminance is improved.

Patent Document 1 discloses a configuration using a cholesteric liquid crystal layer that reflects blue light as a polarized light separating means, particularly for improving the use of blue light emission from the organic electroluminescent layer group. Patent Documents 2 and 3 further disclose a configuration in which a cholesteric liquid crystal layer having a wavelength selective reflectivity corresponding to the emission wavelength of the organic electroluminescent layer group is arranged in a pattern in the polarization separation means.

WO2018/147184 Japanese Patent Laid-Open No. 2014-38713 WO2018/181634

In the method described in Patent Document 1, there was a trade-off between the improvement of the utilization of blue light emission and the blue light of reflection generated based on the cholesteric liquid crystal layer reflecting blue light. On the other hand, if a patterned cholesteric liquid crystal layer is used in the method described in Patent Documents 2 or 3 for reflecting light according to the emission color of the organic electroluminescent layer group, this problem is solved. However, Patent Document 2 discloses a method including a step of directly forming an alignment layer on a transparent electrode and applying a coating liquid for forming a cholesteric liquid crystal layer, and in this method, the solvent of the coating liquid is transparent There is a possibility that the electrode may be affected. Moreover, in the method of patent document 2, since a cholesteric liquid crystal layer is formed between the sealing materials of an organic electroluminescent layer, an outgas etc. may become a cause, and there exists a possibility that an organic electroluminescent layer may deteriorate. On the other hand, the method described in Patent Document 3 is a method of laminating a patterned cholesteric liquid crystal layer on an organic electroluminescent layer group, but in this method, precise alignment between the organic electroluminescent layer and the pattern was difficult.

An object of the present invention is to provide an organic EL image display device having a high utilization efficiency of light emission from an organic electroluminescent layer group and a high luminance over the entire screen. Another object of the present invention is to provide a method for manufacturing such an organic EL image display device.

The present inventors have studied diligently to solve the above problems, and after arranging a film including a layer consisting of a composition for forming a cholesteric liquid crystal layer substantially free of a solvent on the organic electroluminescent layer group, the pattern is formed The thought went crazy for forming, and further examination was repeated, and this invention was completed.

That is, the present invention provides the following [1] to [13].

[1] An organic EL image display device comprising a light emitting element substrate and a circularly polarizing plate, comprising:

The light emitting device substrate includes a reflective layer and a group of organic electroluminescent layers disposed in a matrix on the reflective layer,

The reflective layer, the organic electroluminescent layer group, and the circularly polarizing plate are arranged in this order,

A polarization separation layer is included between the organic electroluminescent layer group and the circularly polarizing plate,

The polarization separation layer includes a polarization separation portion disposed in a pattern to correspond to at least a portion of the organic EL layer of the organic EL layer group,

The polarization separation portion reflects the light of one polarization state among the light emitted by the corresponding organic electroluminescent layer and transmits the light of the other polarization state,

An organic EL image display device, wherein a misalignment occurrence rate between the polarization separation portion and the organic electroluminescent layer corresponding to the polarization separation portion is 10% or less in an entire screen area.

[2] The polarization separation portion comprises a layer formed by fixing a cholesteric liquid crystal phase,

The organic EL image display device according to [1], wherein the layer formed by fixing the cholesteric liquid crystal phase is a layer formed by curing a layer formed of a liquid crystal composition containing a polymerizable liquid crystal compound and a chiral agent.

[3] The organic EL image display device according to [2], wherein the polymerizable liquid crystal compound is a discotic liquid crystal compound.

[4] the polarization separation portion is arranged in a pattern corresponding to the blue organic electroluminescent layer of the organic electroluminescent layer group;

The organic EL image display device according to [2] or [3], wherein the polarization separation portion includes a layer formed by fixing a cholesteric liquid crystal phase having a central wavelength of selective reflection in a wavelength region of blue light.

[5] the polarization separation layer is made of a layer obtained by curing the same composition, and a region other than the polarization separation portion is a visible light transmission region;

The organic EL image display device according to any one of [2] to [4], wherein the visible light transmission region has a central wavelength of selective reflection in an ultraviolet light wavelength region or an infrared light wavelength region.

[6] The organic EL image display device according to [5], wherein the visible light transmitting region has a central wavelength of selective reflection in the ultraviolet light wavelength region.

[7] The organic EL image display device according to any one of [1] to [6], wherein the organic electroluminescent layer group and the polarization separation layer are adhered with an adhesive layer.

[8] A method for manufacturing an organic EL image display device according to any one of [2] to [6], comprising:

Preparing a transfer material comprising a temporary support and a layer formed of the liquid crystal composition formed on the support,

Laminating the transfer material on the light emitting device substrate so that the layers formed of the organic electroluminescent layer group and the liquid crystal composition face each other;

curing the layer formed of the liquid crystal composition, and

peeling off the support

The manufacturing method comprising in this order.

[9] The curing rate of the layer formed of the liquid crystal composition is 0 to 40%,

The production method according to [8], wherein the transfer material is prepared in the form of a roll.

[10] The production method according to [8] or [9], wherein the organic electroluminescent layer group and the layer formed of the liquid crystal composition are adhered with an adhesive layer.

[11] The chiral agent is a photoisomerization chiral agent,

pattern-exposing only a position corresponding to the organic electroluminescent layer of at least a part of the organic electroluminescent layer group of the layer formed of the liquid crystal composition, and

The production method according to any one of [8] to [10], which comprises exposing the entire surface to ultraviolet rays on the layer formed of the liquid crystal composition after the pattern exposure and before the peeling of the support member.

[12] The production method according to [11], which includes heating the layer formed of the liquid crystal composition after the pattern exposure and before the entire surface exposure.

[13] The manufacturing method according to [1] or [12], wherein at least a part of the organic electroluminescent layer group is a group of blue light emitting organic electroluminescent layers of the organic electroluminescent layer group.

Advantageous Effects of Invention According to the present invention, an organic EL image display device with high luminance over the entire surface of the screen, and a method for manufacturing the same, are provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematic sectional drawing of an example of the image display apparatus of this invention.
It is a figure which shows the outline of an example of the process of forming the polarization|polarized-light separation layer in the manufacturing method of the image display apparatus of this invention.

Hereinafter, the present invention will be described in detail.

In this specification, "~" is used in the meaning including the numerical value described before and after that as a lower limit and an upper limit.

In this specification, numerical values, numerical ranges, and qualitative expressions (for example, expressions such as "same", "same", etc.) include generally acceptable errors for image display devices and members used therein. It shall be interpreted as indicating the numerical value, numerical range, and property to be used.

In the present specification, for example, an angle such as “45°”, “parallel”, “vertical” or “orthogonal” means that the difference from the exact angle is within the range of less than 5°, unless otherwise specified. . It is preferable that it is less than 4 degrees, and, as for the difference with strict angle, it is more preferable that it is less than 3 degrees.

In the present specification, when "sense" with respect to circularly polarized light, it means whether it is right circularly polarized light or left circularly polarized light. The sense of circular polarization is defined as right circular polarization when the front end of the electric field vector rotates clockwise as time elapses, and left circular polarization when the front end of the electric field vector rotates in a counterclockwise direction when viewed in a forward direction.

In this specification, the term "sense" is sometimes used with respect to the twist direction of the spiral of the cholesteric liquid crystal. When the twist direction (sense) of the spiral of the cholesteric liquid crystal is right, it reflects right circularly polarized light and transmits left circularly polarized light, and when the sense is left, it reflects left circularly polarized light and transmits right circularly polarized light.

Visible light is light of a wavelength visible to the human eye among electromagnetic waves, and represents light in a wavelength range of 380 nm to 780 nm.

<<Organic EL image display device>>

The image display device of the present invention is an organic EL image display device that displays an image based on light emission from an organic electroluminescent layer group. The organic EL image display device is a self-emission type display device, and has advantages of display performance such as high visibility and no viewing angle dependence compared to a CRT (Cathode Ray Tube) type display device or liquid crystal display device. It also has an advantage that it can be reduced in weight and thickness.

An organic electroluminescent image display apparatus performs image display with the light emitting element board|substrate in which the organic electroluminescent layer group was provided. In general, an organic EL image display device includes a circularly polarizing plate on the image display side of the organic electroluminescent layer group in order to reduce the surface reflection of external light and improve the contrast. An image display device of the present invention includes a polarization separation layer between a light emitting element substrate and a circularly polarizing plate. In the image display device of the present invention, a reflective layer, an organic electroluminescent layer group, a polarization separating layer, and a circularly polarizing plate are arranged in this order.

A schematic cross-sectional view of an example of the image display device of the present invention is shown in Fig. 1 . In the light emitting element substrate 4, three types of organic electroluminescent layers of red light emission (R), green light emission (G), and blue light emission (B) are respectively formed on the surface of the reflection layer (or the substrate having a reflection layer) 3 . . A polarization separation layer 12 including a polarization separation portion 1 is disposed on the light emitting element substrate 4, and a circularly polarizing plate 7 comprising a retardation layer 5 and a polarization layer 6 is disposed thereon. is placed. In the image display device shown in Fig. 1, the polarization separation layer 12 is formed so as to include a polarization separation portion 1 corresponding to the blue organic EL layer, which is an organic EL layer of a part of the organic EL layer group. A portion of the polarization separation layer 12 other than the polarization separation portion 1 is a visible light transmitting region 8 . In addition, in FIG. 1, for the sake of explanation, the polarization separation layer 12 and the light emitting element substrate 4 including the circularly polarizing plate 7 and the polarization separation portion 1 are separately described. You may adhere|attach with an adhesive layer or an adhesive layer in the order shown.

The polarization separation layer in the image display device of the present invention includes a plurality of polarization separation portions corresponding to at least a portion of the organic EL layer group of the organic EL layer group. In the present specification, corresponding means a state in which the organic electroluminescent layer and the polarization separation portion are at the same position or at least partially overlapping each other when the image display device is viewed from the image display side. In the corresponding organic electroluminescent layer and the polarization separation portion, light emission from the organic EL layer group (preferably 50% or more, more preferably 60% or more, still more preferably 70% or more) is reflected at the polarization separation portion Or it should just be in the state which is permeating.

When the image display device is viewed from the image display side, the corresponding organic electroluminescent layer and the polarization separation portion may have the same size, the size of the organic EL layer group may be large, or the size of the polarization separation portion may be large. Among them, it is preferable that the size of the polarization separation portion is large. The image display device of the present invention preferably has a size such that the organic electroluminescent layer is covered with a corresponding polarization separation portion when viewed from the image display side.

In the image display device of the present invention, as described above, the misalignment rate between the polarization separation portion provided to correspond to the organic electroluminescent layer and the corresponding organic electroluminescent layer is 10% or less in the entire screen area. Here, the position shift and the position shift occurrence rate in the area of the entire screen are confirmed as follows.

(displacement)

The position shift between the organic EL pixels arranged in a matrix and the polarization separation layer is measured as follows. The screen display part of the image display apparatus is observed with an optical microscope, and the size of the organic electroluminescent layer (pixel) is measured. Here, the size X of the organic electroluminescent layer refers to the distance between two points with the greatest distance among the outer periphery of the organic electroluminescent layer. For example, in the case of a rectangle, the length of the diagonal line, and in the case of a circle, the diameter becomes the size X of the organic electroluminescent layer.

Next, the center of gravity of the organic electroluminescent layer and the center of gravity of the corresponding polarization separation layer are calculated, and the distance ΔL between them is measured. Here, when ΔL/X≧0.3, it is defined that a positional shift has occurred. The position shift can be measured using an optical microscope.

(Position misalignment rate)

A square with a side of 1 cm is used as 1 unit, and 9 units in the display surface are observed with an optical microscope to measure the misalignment rate. As nine units, the square is taken from the four corners of the screen display unit (display), the portions equidistant from the two corners in the top, bottom, left and right, and the center (center of gravity) of the screen display unit. The misalignment occurrence rate is calculated from the number of organic electroluminescent layers of misalignment with respect to the total number of observed pixels (organic electroluminescent layers). Specifically, the misalignment occurrence rate is (the number of organic electroluminescent layers in which the positional shift with the polarization separation layer has occurred)/(the number of observed organic electroluminescent layers) x 100%.

In each of all the organic electroluminescent layers of said 9 units, it is more preferable that the misalignment occurrence rate is 10 % or less.

As for the position shift occurrence rate, in any of the above cases, it is more preferable that it is 5 % or less.

<Light emitting element substrate>

The light emitting element substrate includes at least a reflective layer and an organic electroluminescent layer group. Usually, a light emitting element substrate should just include a reflective layer and an organic electroluminescent layer group on the TFT substrate which has the organic electroluminescent layer structure formed by the thin film transistor (TFT) etc. on the surface of glass etc.. It is preferable that the organic electroluminescent layer group is normally included as an organic electroluminescent layer group arrange|positioned in matrix form on a TFT substrate.

In the light emitting element substrate, when the TFT substrate, the reflective layer and the organic electroluminescent layer group are arranged in this order, the image display device can extract light in a top emission manner and display an image. In the light emitting element substrate, when the TFT substrate, the organic electroluminescent layer group, and the reflective layer are arranged in this order, the image display device can extract light by a bottom emission method and display an image. Although the image display apparatus of this invention may be a top emission system or a bottom emission system may be sufficient, it is preferable that it is a top emission system.

[Organic electroluminescent layer, organic electroluminescent layer group]

In the organic electroluminescent layer group, a plurality of organic electroluminescent layers may be included in a matrix form on the reflective layer.

In a monochromatic image display device, all the organic electroluminescent layers included in the organic electroluminescent layer group may emit light of the same wavelength. On the other hand, in general, the organic electroluminescent layer group preferably includes organic electroluminescent layers that emit light of different wavelengths, and more preferably include two or more organic electroluminescent layers, particularly three or more organic electroluminescent layers. . It is preferable that the organic electroluminescent layer group contains the organic electroluminescent layer of red light emission, the organic electroluminescent layer of green light emission, and the organic electroluminescent layer of blue light emission.

The organic electroluminescent layer has at least a light emitting layer, and as a functional layer other than the light emitting layer, it means a layer that may include each layer, such as a hole transport layer, an electron transport layer, a hole block layer, an electron block layer, a hole injection layer, and an electron injection layer. do.

The organic electroluminescent layer may use the organic electroluminescent layer group of the microcavity structure described in Unexamined-Japanese-Patent No. 2016-139372.

The reflective layer may be, for example, a reflective electrode. As a reflective electrode, the aluminum electrode generally used for organic electroluminescent device can be used. The light emitting element substrate also includes a transparent electrode such as an Indium Tin Oxide (ITO) electrode. The following are mentioned as an example of the layer structure in a light emitting element board|substrate.

TFT substrate/reflective electrode/organic electroluminescent layer group/transparent electrode

TFT substrate/transparent electrode/organic electroluminescent layer group/reflective electrode

The light-emitting element substrate may further include a barrier layer for sealing the organic electroluminescent layer group, a light extraction layer, and the like.

Regarding the organic electroluminescent layer group, each layer in the organic electroluminescent layer group, the material and configuration of the transparent electrode and the reflective electrode, the order of lamination, and the configuration of the light emitting element substrate, Paragraphs 0081 to 0122 of Japanese Patent Application Laid-Open No. 2012-155177; Japanese Patent Publication No. 4011292 and Japanese Patent Application Laid-Open No. 2016-139372 may be referred to.

<Polarization separation layer, polarization separation region>

The polarization separation layer is a layer including a polarization separation region. When the image display device of the present invention is viewed from the image display side, the polarization separation portion in the polarization separation layer corresponds to a plurality of organic EL layers arranged in a matrix in the organic EL layer group, and is arranged in a pattern, have.

The polarization separation layer preferably includes a region other than the region formed of the polarization separation region. The region other than the polarization separation region may be a visible light transmission region.

In the present specification, the polarization separation portion refers to a portion where polarization separation is performed in the wavelength range of emission of the corresponding organic electroluminescent layer group. Polarization separation refers to reflecting light in one polarization state and transmitting light in the other polarization state. In the image display device of the present invention, the polarization separation may be performed by reflecting the circularly polarized light of one sense and transmitting the circularly polarized light of the other sense.

The polarization separation site may be a site capable of selectively performing polarization separation in a wavelength region of emission of the corresponding organic electroluminescent layer group, or may be a site capable of performing polarization separation in a wavelength region other than the above-mentioned wavelength region.

"Selective polarization separation" refers to polarization separation only in a wavelength region corresponding to the emission wavelength region of the organic electroluminescent layer group to which the polarization separation region corresponds, among visible light regions. Therefore, the polarized light splitting site may be polarized light only in a wavelength range corresponding to the wavelength range of emission of the organic electroluminescent layer group to which the polarized light splitting site corresponds, in the visible light region, substantially in the entire wavelength range of visible light. The polarization separation may be performed, or the polarization separation may be performed in a plurality of wavelength regions such as a red wavelength region, a green wavelength region, and a blue wavelength region.

The polarization separation portion is preferably a portion capable of selectively performing polarization separation in the wavelength range of emission of the corresponding organic electroluminescent layer group.

In the image display device of the present invention, the polarization splitting portion is disposed so that light in a polarized state that does not pass through the circularly polarizing plate among the emission of the organic electroluminescent layer group is reflected at the polarized light splitting portion toward the reflective layer.

The visible light transmittance region as a region other than the region formed by the polarization separation portion of the polarization splitting layer may have a visible light transmittance of 80% to 100%, preferably 90% to 100%. The visible light transmission region is preferably non-reflective at least on the surface on the side of the organic electroluminescent layer group. In particular, it is preferable that the organic electroluminescent layer group is non-reflective in each emission wavelength range. It is also preferable that it is non-reflective in the entire visible light wavelength range. It is preferable that it is 0 % - 5 %, and, as for the visible light reflectance in the surface by the side of the organic electroluminescent layer group of a visible light transmission area|region, it is more preferable that it is 0 % - 2 %.

The visible light transmission region may be, for example, an optically isotropic region, a region having a central wavelength of selective reflection in an ultraviolet light wavelength region or an infrared light wavelength region, or the like. That is, in the present specification, a region for polarization separation of light other than the visible light wavelength region is also referred to as the visible light transmission region. All of the optically isotropic region, the ultraviolet light wavelength region, or the region having a central wavelength of selective reflection in the infrared wavelength region, for example, can be produced using the same composition as the composition for preparing the polarization separation region in the method described later. . That is, the entire polarization separation layer may be manufactured using the same composition.

The plurality of polarization separation portions in the polarization separation layer may be arranged in a pattern corresponding to the organic electroluminescent layer group. The polarization separation layer may be formed of one type of polarization separation portion that reflects light in one polarization state and transmits light in the other polarization state in one wavelength region, and in another wavelength, 1 It may be formed of plural types, preferably three types of polarization separation sites, which reflect light in two polarization states and transmit light in the other polarization state. The reflection wavelengths of the plurality of types of polarization separation sites correspond to the emission wavelengths of the organic electroluminescent layer group included in the organic electroluminescent layer group.

Each of the polarization separation portion and the polarization separation layer may be a single layer or may consist of a plurality of layers. The polarization separation portion and the polarization separation layer preferably include a cholesteric liquid crystal layer. The polarization separation portion and the polarization separation layer may consist of only the cholesteric liquid crystal layer, or may include an alignment layer, a protective layer, and the like in addition to the cholesteric liquid crystal layer. The polarization separation portion and the polarization separation layer may include an optically isotropic layer formed by curing the composition used for forming the cholesteric liquid crystal layer in a state in which the liquid crystal compound is not aligned.

[Cholesteric liquid crystal layer]

In the present specification, the cholesteric liquid crystal layer refers to a layer formed by fixing a cholesteric liquid crystal phase.

It is known that a cholesteric liquid crystal phase exhibits selective reflection of circularly polarized light that selectively reflects circularly polarized light of either sense of right or left circularly polarized light and transmits circularly polarized light of the other sense in a specific wavelength region. . In this specification, circularly polarized light selective reflection is sometimes referred to simply as selective reflection.

A film comprising a layer in which a cholesteric liquid crystal phase exhibiting circular polarization selective reflectivity is fixed, and a film formed of a composition containing a polymerizable liquid crystal compound has been known in the past. can refer to

The cholesteric liquid crystal layer may be a layer in which the alignment of the liquid crystal compound in the cholesteric liquid crystal phase is maintained, and typically, after the polymerizable liquid crystal compound is in the aligned state of the cholesteric liquid crystal phase, ultraviolet irradiation; What is necessary is just a layer which polymerizes and hardens|cures by heating etc., and forms a layer with no fluidity|liquidity, and also changes into the state which does not generate|occur|produce a change in an orientation form by an exterior or an external force. In addition, in the cholesteric liquid crystal layer, it is sufficient if the optical properties of the cholesteric liquid crystal phase are maintained in the layer, and the liquid crystal compound in the layer does not need to have already exhibited liquid crystallinity. For example, a polymeric liquid crystal compound may be made high molecular weight by hardening reaction, and may already lose liquid crystallinity.

The central wavelength λ of the selective reflection of the cholesteric liquid crystal layer depends on the pitch P of the spiral structure in the cholesteric liquid crystal phase (= the period of the spiral), and the average refractive index n and λ=n of the cholesteric liquid crystal layer It follows the relationship of ×P. In addition, in this specification, the central wavelength λ of the selective reflection of the cholesteric liquid crystal layer means a wavelength at the center of gravity position of the reflection peak of the circularly polarized reflection spectrum measured from the normal direction of the cholesteric liquid crystal layer. . In addition, in this specification, the center wavelength of selective reflection means the center wavelength when measured from the normal line direction of a cholesteric liquid crystal layer.

The selective reflection center wavelength and half width of the cholesteric liquid crystal layer can be obtained as follows.

When the transmission spectrum of the cholesteric liquid crystal layer (measured from the normal direction of the cholesteric liquid crystal layer) is measured using a spectrophotometer UV3150 (Shimadzu Corporation), a peak of a decrease in transmittance is seen in the selective reflection band. Among the two wavelengths that are intermediate (average) transmittance between the minimum transmittance of this peak and the transmittance before reduction, if the value of the wavelength on the short wavelength side is λ _l (nm), and the value of the wavelength on the long wavelength side is λ _h (nm), , the central wavelength λ and half width Δλ of the selective reflection can be expressed by the following equations.

λ=(λ _l +λ _h )/2

Δλ=(λ _{h -λ l} )

The selective reflection center wavelength obtained as described above approximately coincides with the wavelength at the center position of the reflection peak of the circularly polarized light reflection spectrum measured from the normal direction of the cholesteric liquid crystal layer.

As can be seen from the formula of λ=n×P, the central wavelength of selective reflection can be adjusted by adjusting the pitch of the spiral structure. In the cholesteric liquid crystal layer used for the polarization separation region, right-circularly polarized light or The central wavelength λ may be adjusted by adjusting the n value and the P value to selectively reflect any one of the left circularly polarized light.

That is, in the image display device of the present invention, the peak (maximum value) of the emission spectrum of the organic electroluminescent layer group used is adjusted to be approximately equal to the central wavelength of the selective reflection of the cholesteric liquid crystal layer in the corresponding polarization separation site. Do it. By matching the wavelength of the emission peak of the organic electroluminescent layer group for image display of the image display device with the central wavelength of selective reflection, the light of one polarization state among the light emitted by the organic electroluminescent layer group is reflected, and the other It is possible to transmit light in a polarized state.

In addition, with respect to the light incident obliquely with respect to the cholesteric liquid crystal layer, the central wavelength of selective reflection shifts to the short wavelength side. In the cholesteric liquid crystal layer of refractive index n ₂ , the central wavelength of selective reflection when _{light rays pass at an angle of θ 2} with respect to the normal direction of the cholesteric liquid crystal layer (the spiral axis direction of the cholesteric liquid crystal layer) is _{λ d} When , λ _d is expressed by the following formula.

λ _d =n _2× P×cosθ ₂

The average refractive index n of the cholesteric liquid crystal layer can be adjusted according to the type of the polymerizable liquid crystal compound or the like.

Since the pitch (P value) of a cholesteric liquid crystal phase depends on the kind of the chiral agent used together with a polymeric liquid crystal compound, or its addition concentration, a desired pitch can be obtained by adjusting these. In addition, as for the method of measuring the sense and pitch of the spiral, the method described in “Introduction to Liquid Crystal Chemistry Experiments” Japanese Liquid Crystal Society edition Sigma Publishing 2007, page 46, and “Liquid Crystal Handbook” Liquid Crystal Handbook Editing Committee Maruzen page 196 can be used. .

In the image display device of the present invention, as the polarization separation portion, a cholesteric liquid crystal layer having a central wavelength of selective reflection corresponding to the wavelength of emission of the organic EL layer in the organic EL layer group may be used. For example, when the organic electroluminescent layer group includes a red light-emitting organic electroluminescent layer group, a green light-emitting organic electroluminescent layer group, and a blue light-emitting organic electroluminescent layer group, the red light wavelength range ( For example, a cholesteric liquid crystal layer having a central wavelength of selective reflection in 580 nm to 700 nm), a cholesteric liquid crystal layer having a central wavelength of selective reflection in a wavelength region of green light (eg, 500 nm to 580 nm), and blue light A configuration including a cholesteric liquid crystal layer having a central wavelength of selective reflection in a wavelength range (eg, 400 nm to 500 nm) is considered. In addition, the cholesteric liquid crystal layer having a central wavelength of selective reflection in the wavelength region of red light, the cholesteric liquid crystal layer having a central wavelength of selective reflection in the wavelength region of green light, and the center of selective reflection in the wavelength region of blue light A configuration using any one or two of the cholesteric liquid crystal layers having a wavelength is conceivable.

In particular, it is preferable to provide a structure in which a polarization separation site, which is a cholesteric liquid crystal layer having a central wavelength of selective reflection in the wavelength region of blue light, is provided in correspondence with the blue organic electroluminescent layer in the organic electroluminescent layer group. In organic EL image display devices, there is a difference in the energy required to emit light of each color, and in general, the degradation of the organic electroluminescent layer of blue light emission is faster than that of the organic electroluminescent layer of green or red color. For this reason, it is because especially the improvement of the utilization efficiency of the light emission from the organic electroluminescent layer of blue light emission is calculated|required.

Further, in the image display device of the present invention, a cholesteric liquid crystal layer having a central wavelength of selective reflection in a wavelength range of ultraviolet light (for example, 10-380 nm) as a visible light transmission region of the polarization separation layer or a wavelength range of infrared light A cholesteric liquid crystal layer having a central wavelength of selective reflection (eg, 780 nm to 2500 nm) may be used.

As each cholesteric liquid crystal layer, a cholesteric liquid crystal layer whose sense of spiral is either right or left according to the sense of circularly polarized light transmitted by the circularly polarizing plate of the image display device of the present invention is used. Specifically, a cholesteric liquid crystal layer that transmits circularly polarized light having the same sense as that of circularly polarized light transmitted by the circularly polarizing plate is used.

The sense of the reflected circularly polarized light of the cholesteric liquid crystal layer coincides with the sense of the spiral. When a plurality of types of cholesteric liquid crystal layers are included in the polarization separation layer, the senses of the spirals are usually all the same.

It is preferable that the wavelength range of the reflection of the polarization separation portion is wider than the wavelength range of the light emission of the corresponding organic electroluminescent layer group. More specifically, it is preferable that the half-width of the selective reflection of the cholesteric liquid crystal layer included in the polarization separation portion is wider than the half-width of the emission spectrum of the organic electroluminescent layer group. This is because, in the organic EL image display device in which the wavelength range of reflection of the polarization separation portion is wider than that of light emission of the organic electroluminescent layer group, the luminance is improved not only in the frontal direction but also in the oblique direction.

The half-width Δλ (nm) of selective reflection of the cholesteric liquid crystal layer depends on the birefringence Δn of the liquid crystal compound and the pitch P, and follows the relationship Δλ=Δn×P. For this reason, control of the half-width of selective reflection can be performed by adjusting ?n. Adjustment of (DELTA)n can be performed by adjusting the kind of a polymeric liquid crystal compound, its mixing ratio, or controlling the temperature at the time of orientation fixation.

The thickness of the cholesteric liquid crystal layer is not particularly limited as long as it exhibits the above characteristics, but is preferably in the range of 1.0 µm or more and 20 µm or less, more preferably 2.0 µm or more and 10 µm or less.

[Liquid Crystal Composition]

The cholesteric liquid crystal layer is formed by curing a layer of a liquid crystal composition including a polymerizable liquid crystal compound.

The liquid crystal composition containing the polymerizable liquid crystal compound preferably further contains other polymerizable monomers, surfactants, chiral agents, polymerization initiators, and the like. For other polymerizable monomers, surfactants, chiral agents, and polymerization initiators, for example, WO2018/181634 and Japanese Patent Application Laid-Open No. 2016-197219 can be referred to.

(Polymerizable liquid crystal compound)

The polymerizable liquid crystal compound is a liquid crystal compound having a polymerizable group. A rod-shaped liquid crystal compound may be sufficient as a polymeric liquid crystal compound, and a disk-shaped liquid crystal compound may be sufficient as it.

Examples of the polymerizable group include an acryloyl group, a methacryloyl group, an epoxy group, and a vinyl group. By polymerizing the polymerizable liquid crystal compound, the orientation of the liquid crystal compound can be fixed. The liquid crystal compound having a polymerizable group is preferably a monomer or a liquid crystal compound having a degree of polymerization of less than 100 and a relatively low molecular weight.

(disk-like liquid crystal compound)

As a discoid liquid crystal compound, For example, Unexamined-Japanese-Patent No. 2007-108732, Unexamined-Japanese-Patent No. 2010-244038, Unexamined-Japanese-Patent No. 2013-195630, Unexamined-Japanese-Patent No. 10-307208, and Unexamined-Japanese-Patent No. The thing described in publication 2000-171637 is mentioned. In Japanese Patent Application Laid-Open No. 2013-195630, there is a description that, in general, a compound having a triphenylene structure is preferable for the discotic liquid crystal compound. On the other hand, a discotic liquid crystal compound having a trisubstituted benzene structure rather than a triphenylene structure has a higher Δn and a wider reflection wavelength band, so it can be appropriately selected as needed.

(rod-shaped liquid crystal compound)

Examples of the rod-like liquid crystal compound include azomethines, azoxyls, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, and cyanosubstituted phenylpyrimidines. , alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes, and alkenylcyclohexylbenzonitriles are preferably used.

As a rod-shaped liquid crystal compound which is a polymerizable liquid crystal compound, Makromol. Chem., Vol. 190, p. 2255 (1989), Advanced Materials Vol. 5, p. 107 (1993), U.S. Patent Publication Nos. 4683327, 5622648, 5770107, WO95/22586, 95/24455, 97/00600, 98/23580, 98/52905, Japanese Patent Application Laid-Open Nos. 1-272551, 6-16616, 7-110469, 11-80081, and Japanese Patent Application The compound described in each publication of 2001-64627, etc. can be used. Moreover, as a rod-shaped liquid crystal compound, the compound of Unexamined-Japanese-Patent No. 11-513019 or 2007-279688 can also be used preferably, for example.

You may use together 2 or more types of polymerizable liquid crystal compounds. When two or more types of polymerizable liquid crystal compounds are used together, orientation temperature can be reduced.

[Layer formed of liquid crystal composition]

The polarization separation layer including the cholesteric liquid crystal layer may be formed using a layer formed of the liquid crystal composition.

The layer formed of the liquid crystal composition is a layer obtained by curing the liquid crystal composition at a curing rate of 0 to 40%. Specifically, the layer formed of the liquid crystal composition is a layer made of an uncured liquid crystal composition, or a layer obtained by curing the layer comprising the liquid crystal composition at a curing rate of 40% or less. By being a layer hardened|cured by 0 to 40% of hardening rates, patterning on an organic electroluminescent display can be performed. Specifically, it can be set as the state which can raise|generate the change of the pitch of a spiral structure at the time of patterning on an organic electroluminescent display apparatus. The curing rate is preferably 0 to 40%, more preferably 0 to 30%, and still more preferably 0 to 10%.

A curing rate is computable as follows, for example, when a liquid crystal composition contains the polymeric compound which has a (meth)acryloyl group.

KBr-IR measurement of the coating film before curing using NICOLET6700 FT-IR manufactured by Thermo Electron Corporation, the peak of the polymerizable carbon-carbon unsaturated double bond when the area ^{of the peak (1660-1800 cm -1) of the carbonyl group is 1} The area (808cm ^-1 ) is calculated|required, and let it be _{Area ini.} Moreover, the peak area of a polymerizable carbon-carbon unsaturated double bond when the peak area of a carbonyl group is 1 is calculated|required from KBr-IR measurement of the film|membrane which calculates|requires a cure rate, and let it be Area _obs . Based on the obtained Area _ini and Area _obs , it can be computed with the following formula.

(1-Area _obs /Area _ini )×100%

The layer formed of the liquid crystal composition may be a layer (coating film) formed by applying a coating liquid containing a liquid crystal composition and a solvent to the surface of a support body or an alignment layer formed on the surface of the support body, and then vaporizing the solvent. The layer formed of such a liquid crystal composition, that is, substantially does not contain a solvent. The layer formed of the liquid crystal composition may further be a layer obtained by curing the coating film on the supporting body at a curing rate of 40% or less.

The layer formed of the liquid crystal composition is prepared as a transfer material including both the support and, if necessary, the alignment layer formed on the support, and is used for the production of the polarization separation layer in the organic EL image display device of the present invention. there may be As the transfer material, a previously prepared material may be used. For example, you may develop the transfer material manufactured in roll shape and use it for preparation of the polarization separation layer in an organic electroluminescent image display apparatus. Specifically, you may laminate|stack on a light emitting element board|substrate, developing a roll. The supporting body or the supporting body and the alignment layer may be peeled off after the polarization separating layer is prepared.

(branch support)

Examples of the support include polyester such as polyethylene terephthalate (PET), polycarbonate, acrylic resin, epoxy resin, polyurethane, polyamide, polyolefin, cellulose derivative, silicone, or a glass plate.

Although the thickness of a branch support body is not specifically limited, What is necessary is just about 5 micrometers - 1000 micrometers, Preferably it is 10 micrometers - 250 micrometers, More preferably, what is necessary is just 15 micrometers - 120 micrometers.

(menstruum)

There is no restriction|limiting in particular as a solvent in the coating liquid for formation of the layer formed from the liquid-crystal composition, Although it can select suitably according to the objective, An organic solvent is used preferably.

The organic solvent is not particularly limited and may be appropriately selected according to the purpose, and examples thereof include ketones, alkyl halides, amides, sulfoxides, heterocyclic compounds, hydrocarbons, esters, and ethers. have. These may be used individually by 1 type, and may use 2 or more types together. Among these, when the load on the environment is considered, ketones are especially preferable.

(Orientation layer)

The layer formed of the liquid crystal composition may be provided on the alignment layer. The alignment state of the liquid crystal compound in the liquid crystal composition can be regulated by the alignment layer. In addition, regulation of the orientation state of a liquid crystal compound may be achieved by the support body by which the rubbing process was carried out.

The orientation layer may be any layer as long as it can impart orientation to the optically anisotropic layer. A preferred example of the alignment layer is a layer in which an organic compound such as a polymer (resin such as polyimide, polyvinyl alcohol, polyester, polyarylate, polyamideimide, polyetherimide, polyamide, or modified polyamide) is rubbed. , a photo-alignment layer that expresses the alignment property of liquid crystals by polarized light irradiation typified by azobenzene polymer or cinnamate polymer, an oblique vapor deposition layer of an inorganic compound, and a layer having micro grooves, and also ω-tricoseic acid, dioctadecylmethylammonium An accumulation film formed by the Langmuir-Blodgett method (LB film), such as chloride and methyl stearate, or a layer in which a dielectric is oriented by application of an electric field or a magnetic field is mentioned. It is preferable that polyvinyl alcohol is included in the aspect of rubbing as an orientation layer, and it is especially preferable that it can bridge|crosslink with at least any one layer above or below an orientation layer. Specifically, the orientation layer of Unexamined-Japanese-Patent No. 2009-69793, Unexamined-Japanese-Patent No. 2010-113249, and Unexamined-Japanese-Patent No. 2011-203636 can be used. Moreover, a photo-alignment layer can also be used suitably. This is because, when the photo-alignment layer is used, the occurrence of alignment defects caused by minute foreign matter is suppressed, and the cholesteric liquid crystal layer can be formed with high optical performance even in a fine shape. For example, the liquid crystal aligning agent (For example, the liquid crystal aligning agent containing epoxy containing polyorganosiloxane) of Unexamined-Japanese-Patent No. 2015-26050 can be used. In order to fully exhibit the orientation regulating force of an orientation layer, you may control the temperature of the apply|coated liquid crystal composition, and you may perform the process (orientation process) which expresses a desired phase.

It is preferable that they are 0.01 micrometer - 5.0 micrometers, and, as for the thickness of an orientation layer, it is more preferable that they are 0.05 micrometer - 2.0 micrometers.

(application, orientation)

The method of applying the liquid crystal composition to the supporting body or the alignment layer is not particularly limited and may be appropriately selected according to the purpose, for example, wire bar coating method, curtain coating method, extrusion coating method, direct gravure coating method, reverse gravure coating method. A coating method, a die coating method, a spin coating method, a dip coating method, a spray coating method, a slide coating method, etc. are mentioned. By heating the applied liquid crystal composition, the solvent is vaporized. The liquid crystal molecules may be aligned simultaneously by heating. 200 degrees C or less is preferable and, as for the heating temperature for cholesteric orientation, 130 degrees C or less is more preferable. By this orientation treatment, a layer in which the polymerizable liquid crystal compound is twisted and oriented so as to have a helical axis in a direction substantially perpendicular to the film plane is obtained.

(Hardening)

When the layer formed of the liquid crystal composition is formed as a cured layer, as described above, the curing rate is 40% or less. Such curing can be achieved, for example, by irradiating the entire surface with ultraviolet rays of the irradiation amount and wavelength of the pattern exposure described later.

[Formation of polarization separation layer]

The polarization separation layer including the cholesteric liquid crystal layer is formed by laminating the layer formed of the liquid crystal composition on the support on the light emitting device substrate so that the layer formed of the organic electroluminescent layer group and the liquid crystal composition face each other, and then the layer formed of the liquid crystal composition It is preferable to form by hardening. This is because selective curing according to the portion corresponding to the organic electroluminescent layer in the organic electroluminescent layer group becomes possible by this procedure.

An example of the polarization separation layer formation process in manufacture of the image display apparatus of this invention in FIG. 2 is shown. In this example, first, a transfer material including a support 10 , an alignment layer 11 , and a layer 12 formed of a liquid crystal composition is applied to a light emitting element substrate 4 , and an organic electroluminescent layer 2 is formed. The organic electroluminescent layer group and the layer 12 formed of the liquid crystal composition are adhered to each other with the pressure-sensitive adhesive layer 9 (Step 1 in Fig. 2). With respect to the obtained laminated body, as shown in process 2 in FIG. 2, using the photomask 20, ultraviolet-ray irradiation is carried out from the direction of an arrow, and pattern exposure is carried out. The pattern exposure is performed so that only a portion corresponding to the organic electroluminescent layer that emits light of a specific color (for example, blue) is irradiated with ultraviolet rays. After that, heat aging is performed to change the pitch of the spiral structure. Next, as shown in the process 3 in FIG. 2, ultraviolet irradiation is carried out from the direction of an arrow. Finally, the support body 10 and the orientation layer 11 are peeled off (Step 4 in FIG. 2 ).

Hereinafter, each process required in formation of a polarization separation layer is demonstrated.

(patterning process)

The curing of the layer formed of the liquid crystal composition includes a patterning process in order to form a polarization separation layer having a polarization separation portion in a pattern by performing selective curing step by step according to a portion corresponding to the organic EL layer in the organic EL layer group. It is preferable to do it in this way.

In order to form a polarization separation site showing polarization separation in a part of the polarization separation layer, or to form a polarization separation layer including a plurality of types of polarization separation sites exhibiting polarization separation at different wavelengths, a cholesteric liquid crystal layer can be formed by patterning. By using the pattern-shaped cholesteric liquid crystal layer in which the selective reflection wavelength is adjusted corresponding to the emission wavelength of the organic electroluminescent layer of the light emitting element substrate, light utilization efficiency can be improved more. By forming the cholesteric liquid crystal layer by patterning, it is also possible to form a polarized light separation region and a visible light transmitting region on the pattern.

For patterning, a method using solvent development, a method using a photoisomerization chiral agent (Japanese Patent Application Laid-Open No. 2001-159706), a method of pre-orienting and fixing a cholesteric liquid crystal layer using a laser or a thermal head ( JP 2001-4822 , JP 2001-4824 ), the inkjet method ( JP 2001-159709 ), and a method using the temperature dependence of the cholesteric helix pitch (JP 2001 JP 2001 ) -159708), a method of stepwise varying the amount of ultraviolet irradiation during curing of the liquid crystal composition between regions, and the like.

It is preferable to use the method using a photoisomerization chiral agent for patterning.

The method of using a photoisomerization chiral agent can be performed as follows as an example. First, a cholesteric liquid crystal layer having a central wavelength of selective reflection in an ultraviolet wavelength region is formed over the entire surface using a liquid crystal composition including a photoisomerization chiral agent. Thereafter, pattern exposure (ultraviolet ray irradiation) is carried out only at positions corresponding to at least a part of the organic electroluminescent layer in the organic electroluminescent layer group. Then, the layer is heat-aged to change the pitch of the spiral structure with respect to the pattern-exposed portion to adjust the selective reflection wavelength. Usually, depending on heat aging, the pitch of the spiral structure can be lengthened, and the selective reflection wavelength can be made into a longer wavelength. Alternatively, first, the entire surface of the cholesteric liquid crystal layer having the central wavelength of selective reflection in the ultraviolet wavelength region is formed. Thereafter, a part of the cholesteric liquid crystal layer is immobilized by pattern exposure (ultraviolet ray irradiation) in a state having a central wavelength of selective reflection in an ultraviolet wavelength region or an infrared wavelength region to form a visible light transmission region. Then, light of the absorption wavelength of the chiral agent is selectively irradiated to each region with an appropriate amount according to each region having a central wavelength of selective reflection to be formed. Thereby, the chiral agent is isomerized, and the pitch of the helical structure corresponding to each area|region can be obtained.

In either case, the orientation of each region is fixed by exposing the entire surface to ultraviolet rays at the end, and a pattern of a cholesteric liquid crystal layer having a visible light transmission region in one layer and a central wavelength of selective reflection in a desired wavelength region. A polarization separation layer may be formed.

As a method of said pattern exposure, contact exposure using a mask, proximity exposure, projection exposure, etc. are mentioned. As an irradiation wavelength of the light source of the said exposure, it is preferable to have a peak at 250-450 nm, and it is more preferable to have a peak at 300-410 nm. Specifically, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp, a blue laser, etc. are mentioned. Examples of preferred illuminance, and 1 to 40mw / cm ² or so, more preferably ² ~ 30mw / cm 2 or so, more preferably 3 ~ 25mw / cm ² or so.

As a preferable exposure amount, ^{it is about 3-300 mJ/cm<2>} normally, More preferably, it is ^{about 5-200 mJ/cm<2>} , More preferably, it is about ^{10-150 mJ/cm<2>.}

Although it does not specifically limit as temperature in the case of heat-aging after pattern exposure, For example, 50 degreeC - 150 degreeC, Preferably it is 60 degreeC - 130 degreeC for 1 second - 3 minutes, Preferably, 3 seconds - 1 Minute heating may be performed.

The exposure amount of whole surface exposure should just be an amount by which the material hardens|hardens enough. As a preferable exposure amount, ^{it is about 110-2000 mJ/cm<2>} normally, More preferably, it is ^{about 120-1000 mJ/cm<2>} , More preferably, it is about ^{140-500 mJ/cm<2>.}

It is preferable to perform pattern exposure and whole surface exposure so that it may differ in the wavelength or illumination intensity of the ultraviolet-ray to irradiate, or both, for example.

For example, when performing so that the wavelengths are different, j-line (wavelength 313 nm) can be used for pattern exposure, and i-line|wire (wavelength 365 nm) can be used for whole surface exposure. The exposure wavelength may be different by using a band pass filter or the like.

When carrying out so that illuminance may differ, it is preferable to perform pattern exposure with low illuminance, and to perform whole surface exposure with high illuminance. Roughness of the pattern is exposed in this case, 1 ~ 40mW / cm ² level are preferred, and 2 to 30mW / cm ² is about more preferably, 3 ~ 20mW / cm ^2, the degree is more preferred.

Illumination of the entire surface exposure, 10 ~ 150mW / cm ² level are preferred, and 20 to 130mW / cm ² is about more preferably, 25 ~ 100mW / cm ² degree is more preferred.

In order to accelerate|stimulate a photopolymerization reaction, you may light irradiation under heating conditions or nitrogen atmosphere.

As an example of a photoisomerization chiral agent, the compound represented by the following general formula (1) of Unexamined-Japanese-Patent No. 2002-302487 is mentioned.

[Formula 1]

In the formula, R ^a and R ^b each independently represent a hydrogen atom, an alkyl group (methyl group, ethyl group, etc.), an aryl group, a heterocyclic group, an alkenyl group or an alkynyl group, R ^c and R ^d are each independently hydrogen An atom, an alkyl group, or an alkoxycarbonyl group is represented, and L represents a divalent group (metayne group, biphenylene group, etc.). The binaphthyl moiety has either (R) or (S) axial sacrificial properties.

A polarization separation layer constituted by using a layer formed of a plurality of liquid crystal compositions may be formed using pattern exposure. For such a configuration, reference can be made to the description of paragraphs 0119 to 0121 of WO2018/181634.

<Circular Polarizer>

A circularly polarizing plate is provided in the image display side of an organic electroluminescent layer group for reduction of surface reflection of external light and contrast improvement in an organic electroluminescent image display apparatus. As a circularly-polarizing plate, a well-known circularly-polarizing plate can be used as a circularly-polarizing plate used in organic electroluminescent image display apparatus.

In manufacture of the image display apparatus of this invention, what is necessary is just to form a circularly polarizing plate on the polarization separation layer formed on the light emitting element board|substrate, for example.

The circularly polarizing plate includes a retardation layer and a polarizing layer. The circularly polarizing plate may have other layers, such as a contact bonding layer and a surface protective layer. In the image display device of the present invention, the circularly polarizing plate is arranged such that the polarization separating layer, the retardation layer, and the polarizing layer are in this order. The circularly polarizing plate may consist of a retardation layer and a polarizing layer. It is preferable that the retardation layer consists of a quarter wave plate, and it is preferable that the polarizing layer consists of a linear polarizing plate.

The linear polarizing plate transmits a specific linearly polarized light among the light passing through it and absorbs the linearly polarized light orthogonal thereto. As a linear polarizing plate, for example, polyvinyl alcohol absorbs iodine and stretches, and triacetyl cellulose protective layers are formed on both sides of a film to which a polarization function is provided, or metal nanorods such as Ag are added to polyvinyl alcohol. and stretched, etc. can be used.

The quarter-wave plate may be a retardation layer functioning as a quarter-wave plate in the visible region. Examples of the quarter-wave plate include a single-layered quarter-wave plate, a broadband quarter-wave plate in which a quarter-wave plate and a half-wave retarder are laminated, and the like, and can be suitably used.

In this specification, the phase difference means front retardation. The phase difference can be measured using the polarization phase difference analyzer AxoScan made by AXOMETRICS.

There is no restriction|limiting in particular as a quarter wave plate, According to the objective, it can select suitably. For example, a quartz plate, a stretched polycarbonate film, a stretched norbornene-based polymer film, a transparent film oriented containing inorganic particles exhibiting birefringence such as strontium carbonate, a thin film in which an inorganic dielectric is obliquely deposited on a support, or a support Alternatively, a liquid crystal composition is applied to an alignment film, a polymerizable liquid crystal compound in the liquid crystal composition is formed therein in a nematic orientation in a liquid crystal state, and then fixed by photocrosslinking or thermal crosslinking, and the like. You may use what combined these two or more.

<Adhesive layer>

The image display device of the present invention may include an adhesive layer between the organic electroluminescent layer group and the polarization separation layer. In particular, the organic electroluminescent layer group and the polarization separation layer may be directly adhered to each other by an adhesive layer. In the production of the image display device of the present invention, when the organic electroluminescent layer group and the layer formed of the liquid crystal composition are laminated to face each other, by adhering the organic electroluminescent layer group and the layer formed of the liquid crystal composition with an adhesive layer, the above configuration is obtained lose As an adhesive layer, SK-2047, SK-2057 (made by Soken Chemical Co., Ltd.), etc. can be used.

<Adhesive layer>

The image display apparatus of this invention may contain the adhesive layer for adhesion|attachment of each layer. The adhesive used for forming the adhesive layer includes a hot melt type, a thermosetting type, a photocuring type, a reaction curing type, and a pressure-sensitive adhesive type that does not require curing from the viewpoint of the curing method. Acrylate, epoxy, epoxy acrylate, polyolefin, modified olefin, polypropylene, ethylene vinyl alcohol, vinyl chloride, chloroprene rubber, cyanoacrylate, polyamide, polyimide, polystyrene compounds, such as a polyvinyl butyral system, can be used. From the viewpoint of workability and productivity, a photocuring type, particularly an ultraviolet curing type, is preferable as the curing method, and from the viewpoint of optical transparency and heat resistance, the material is acrylate type, urethane acrylate type, epoxy acrylate type, etc. It is preferable to use

The adhesive layer may be a highly transparent adhesive transfer tape (OCA tape). In particular, it is preferable to use an OCA tape for bonding an organic EL device substrate and a film (such as a laminate including a polarization separation layer) provided thereon. As a highly transparent adhesive transfer tape, the commercial item for image display apparatuses, especially the commercial item for the image display part surface of an image display apparatus may be used. As an example of a commercial item, the adhesive sheet (PD-S1 etc.) made from Panac Corporation, the MHM series adhesive sheet of Nichiei Kako Co., Ltd., etc. are mentioned.

It is preferable that they are 0.1 micrometer - 10 micrometers, and, as for the thickness of a contact bonding layer, it is more preferable that they are 0.5 micrometer - 5.0 micrometers.

Example

Hereinafter, the present invention will be described in more detail by way of Examples. Materials, reagents, amounts of substances, ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Accordingly, the scope of the present invention is not limited to the following examples.

In Examples, the organic EL image display device is sometimes referred to as OLED.

(Preparation of alignment film composition A)

The mixture of each component shown below was stirred and melt|dissolved in the container heat-retained at 80 degreeC, and the orientation film composition A was prepared.

──────────────────────────────────

Alignment film composition A (parts by mass)

──────────────────────────────────

pure 97.2

PVA-205 (made by Kurare) 2.8

──────────────────────────────────

A coating liquid C-1 for a cholesteric liquid crystal layer having the following composition was prepared.

──────────────────────────────────

Coating liquid C-1 for cholesteric liquid crystal layer (parts by mass)

──────────────────────────────────

Discoid liquid crystal compound (Compound 101) 80

· Discoid liquid crystal compound (Compound 102) 20

・Polymerizable monomer 1 10

・Surfactant 1 0.3

・KAYACURE DETX-S (manufactured by Nippon Kayaku Co., Ltd.) 3

・Cyral agent 1 7.0

・Methyl ethyl ketone 290

・Cyclohexanone 50

──────────────────────────────────

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Example 1]

(Production of cholesteric liquid crystal film C1)

The cholesteric liquid crystal layer coating liquid C-1 was apply|coated to the rubbing-processed surface of the PET film (Cosmoshine 4100; Toyobo make) of a support body using the slit coater. Subsequently, the coating film was dried at 70 ° C. for 2 minutes, and after vaporizing the solvent, heat aging was performed at 110 ° C. for 3 minutes to obtain a uniform orientation state, and then a 16 μm PET protective film was pasted together to form a cholesteric liquid crystal film. C1 was made.

(Production of OLED evaluation samples)

A polarizing plate and an optical film were peeled from organic electroluminescent image display apparatus SC-04E (made by Samsung Electronics), the surface of the barrier layer which protects a light emitting element was exposed, and it was set as the light emitting element board|substrate. On the barrier layer surface of the light emitting element substrate, an adhesive (SK-2057; manufactured by Soken Chemicals) is interposed so that the cholesteric liquid crystal surface of the cholesteric liquid crystal film C1 from which the protective film has been peeled is aligned with the barrier layer. After bonding together, using EXECURE3000-W manufactured by HOYA-SCHOTT, a band pass filter UZ0313 (manufactured by Asahi Bunko) and a photomask were irradiated with j-ray UV (ultraviolet) light having an ^{illuminance of 3 mW/cm 2 for 8 seconds.} Then, by heating again for 10 second on a 110 degreeC hotplate, the reflected wavelength of the exposure part A was converted to the long wavelength side. In addition, the layer having a cholesteric liquid crystal layer pattern by irradiating i-line UV light with an ^{illuminance of 30 mW/cm 2} for 10 seconds under a nitrogen atmosphere at room temperature and fixing the orientation of the exposed portion (A) and the remaining portion (B). has produced The reflection center wavelength in the portion A was 450 nm, and the reflection center wavelength in the portion B was 350 nm. At this time, as the photomask, an opening was used in advance of a blue pixel (an organic electroluminescent layer emitting blue light) on the light emitting element substrate. Thereafter, the supportive PET film was peeled off, and the polarizer (polarizing layer), optically anisotropic layer A (λ/2 plate), and optically anisotropic layer B prepared according to the procedure shown in Example 1 of WO2016/194801 thereon The circularly polarizing plate (CP1) which consists of (λ/4 plate) was bonded together with the adhesive, and the image display apparatus for evaluation was produced. Further, in the circularly polarizing plate CP1, a polarizer, an optically anisotropic layer A (λ/2 plate), and an optically anisotropic layer B (λ/4 plate) are arranged in this order, and observed from the polarizer side, the transmission axis of the polarizer is When the counterclockwise direction was expressed as a positive value as a reference (0°C), the angle of the slow axis of the λ/2 plate was -72.5° and the angle of the slow axis of the λ/4 plate was -12.5°. In addition, bonding was performed so that the optically anisotropic layer B and a glass substrate might contact.

[Example 2]

The OLED evaluation sample was produced in the procedure of Example 1 except having apply|coated the cholesteric liquid crystal layer coating liquid C-1 without carrying out the rubbing process of the PET film of the support body in Example 1.

[Example 3]

As the support, a commercially available triacetylcellulose film “Z-TAC” (manufactured by Fujifilm Corporation) having a thickness of 40 μm was used. After the Z-TAC was passed through a dielectric heating roll having a temperature of 60 ° C., and the film surface temperature was raised to 40 ° C., an alkali solution of the composition shown below was applied to one side of the film at an application amount of 14 ml/m ² using a bar coater. It was coated, heated at 110°C, and conveyed under a steam-type far-infrared heater manufactured by Noritake Co., Ltd. for 10 seconds. Subsequently, the same as using a bar coater, was coated with a pure 3ml / m ^2. Subsequently, after repeating water washing using a fountain coater and dehydration using an air knife three times, it was conveyed to a drying zone at 70°C for 10 seconds and dried to prepare an alkali saponification-treated acetylcellulose transparent support.

──────────────────────────────────

Composition of alkali solution (parts by mass)

──────────────────────────────────

potassium hydroxide 4.7

water 15.8

isopropanol 63.7

Surfactants

SF-1: C ₁₄ H ₂₉ O(CH ₂ CH ₂ O) ₂₀ H 1.0

propylene glycol 14.8

──────────────────────────────────

The alignment film composition A was uniformly applied using a bar coater on the saponified triacetyl cellulose film having a thickness of 40 μm, and then dried in an oven at 100° C. for 2 minutes to obtain a support including an alignment film having a thickness of 0.5 μm. A rubbing treatment was applied to the alignment film in a direction parallel to the application direction. The cholesteric liquid crystal layer coating liquid C-1 was applied on the rubbing surface. The subsequent process was processed similarly to Example 1, and the OLED evaluation sample was produced.

[Example 4]

In Example 3, the same treatment as in Example 1 was performed, except that the cholesteric liquid crystal layer coating liquid C-1 was applied directly on the support without performing alignment film formation and rubbing treatment, and an OLED evaluation sample was obtained made

(Luminance evaluation)

After the OLED evaluation sample is turned on and the entire surface is colored blue, it is installed on a mount, and a spectroradiometer SR-3 (manufactured by Topcon Co., Ltd.) 2 m away in the normal direction to the OLED evaluation sample (directly in front) , and luminance evaluation was performed. Brightness evaluation was performed by evaluating the improvement rate of a brightness|luminance with the following reference|standard with respect to the brightness|luminance of the image display apparatus which does not have a corresponding cholesteric material.

A: The luminance improvement rate is 30% or more

B: The luminance improvement rate is less than 30% and 15% or more

C: The luminance improvement rate is less than 15% and 5% or more

D: The luminance improvement rate is less than 5%

(reflectance evaluation)

After the OLED evaluation sample was extinguished, it installed on the mount, the spectroradiometer SR-3 (manufactured by Topcon Co., Ltd.) in front of 2 m was arranged at a polar angle of 45° with respect to the OLED evaluation sample, and the reflectance was evaluated.

(Evaluation of the occurrence rate of misalignment of cholesteric patterns for OLED light-emitting pixels)

The center of gravity of each OLED light emitting pixel (a blue light emitting organic electroluminescent layer) and a corresponding cholesteric pattern (polarized light separation site) was measured using an optical microscope. When the distance ΔL between the two was measured and the size of the organic electroluminescent layer was set to X, the pixel having a position shift was defined as ΔL/X≧0.3.

With 1 cm × 1 cm as 1 unit, 9 units of the intersection of the top, middle, bottom, left, and right of the screen (display) (four corners, the portion equidistant from the two corners in the upper, lower, left and right, and the center of the screen display unit (center of gravity)) In , the total number of pixels (the number of organic electroluminescent layers emitting blue light) and the number of pixels in which misalignment occurs were counted using an optical microscope, and “(number of pixels in which misalignment)/(total number of pixels)” ) × 100%” was calculated and determined as follows.

A: The occurrence rate of position misalignment is 5% or less

B: Position shift occurrence rate is greater than 5% and less than or equal to 10% (this is a practically acceptable level)

C: Position shift occurrence rate is greater than 10% and less than or equal to 15%

D: The occurrence rate of position misalignment is greater than 15%

[Table 1]

The OLED evaluation sample produced above was displayed in white on the entire surface, and as a result of visual inspection in the panel front direction and the polar angle 45° direction, there was no color unevenness at any angle, and good display properties were exhibited. On the other hand, as a result of performing the same evaluation with the OLED evaluation sample described in the comparative example, color nonuniformity was generate|occur|produced also at any angle. Although the mechanism by which the color nonuniformity did not generate|occur|produce in the evaluation sample which consists of this invention is not clear, it is estimated that there existed an unexpected effect derived from the low positional shift occurrence rate.

1 Polarization separation site
2 organic electroluminescent layer
3 Reflective layer (substrate)
4 light emitting device substrate
5 retardation layer
6 Polarizing layer
7 Circular Polarizer
8 Optically isotropic or visible light transmission region with a central wavelength of selective reflection in the ultraviolet light wavelength region
9 adhesive layer
10 branches
11 alignment layer
12 A layer formed of a liquid crystal composition or a polarization separation layer
20 photomask

Claims (13)

An organic EL image display device comprising a light emitting element substrate and a circularly polarizing plate, comprising:
The light emitting device substrate includes a reflective layer and a group of organic electroluminescent layers disposed in a matrix on the reflective layer,
The reflective layer, the organic electroluminescent layer group, and the circularly polarizing plate are arranged in this order,
A polarization separation layer is included between the organic electroluminescent layer group and the circularly polarizing plate,
The polarization separation layer includes a polarization separation portion disposed in a pattern to correspond to at least a portion of the organic EL layer of the organic EL layer group,
The polarization separation portion reflects the light of one polarization state among the light emitted by the corresponding organic electroluminescent layer and transmits the light of the other polarization state,
An organic EL image display device, wherein a misalignment occurrence rate between the polarization separation portion and the organic electroluminescent layer corresponding to the polarization separation portion is 10% or less in an entire screen area. The method according to claim 1,
The polarization separation portion comprises a layer formed by fixing a cholesteric liquid crystal phase,
The layer formed by fixing the cholesteric liquid crystal phase is an organic EL image display device in which a layer formed of a liquid crystal composition including a polymerizable liquid crystal compound and a chiral agent is cured. 3. The method according to claim 2,
The organic EL image display device wherein the polymerizable liquid crystal compound is a discotic liquid crystal compound. 4. The method according to claim 2 or 3,
The polarization separation portion is arranged in a pattern corresponding to the blue organic electroluminescent layer of the organic electroluminescent layer group,
The organic EL image display device, wherein the polarization separation portion includes a layer formed by fixing a cholesteric liquid crystal phase having a central wavelength of selective reflection in a wavelength region of blue light. 5. The method according to any one of claims 2 to 4,
The polarization separation layer is made of a layer obtained by curing the same composition, and a region other than the polarization separation region is a visible light transmission region,
The organic EL image display device in which the visible light transmission region has a center wavelength of selective reflection in an ultraviolet light wavelength region or an infrared light wavelength region. 6. The method of claim 5,
An organic EL image display device in which the visible light transmission region has a center wavelength of selective reflection in an ultraviolet light wavelength region. 7. The method according to any one of claims 1 to 6,
An organic EL image display device in which the organic electroluminescent layer group and the polarization separation layer are adhered to each other with an adhesive layer. As a manufacturing method of the organic electroluminescent image display apparatus in any one of Claims 2-6,
Preparing a transfer material comprising a support and a layer formed of the liquid crystal composition formed on the support,
Laminating the transfer material on the light emitting device substrate so that the layers formed of the organic electroluminescent layer group and the liquid crystal composition face each other;
curing the layer formed of the liquid crystal composition, and
The said manufacturing method comprising peeling the said support body in this order. 9. The method of claim 8,
The curing rate of the layer formed of the liquid crystal composition is 0 to 40%,
wherein the transfer material is prepared in roll form. 10. The method according to claim 8 or 9,
A manufacturing method in which the organic electroluminescent layer group and the layer formed of the liquid crystal composition are adhered to each other with an adhesive layer. 11. The method according to any one of claims 8 to 10,
The chiral agent is a photoisomerized chiral agent,
pattern-exposing only a position corresponding to the organic electroluminescent layer of at least a part of the organic electroluminescent layer group of the layer formed of the liquid crystal composition, and
A manufacturing method comprising exposing the entire surface to ultraviolet light on the layer formed of the liquid crystal composition after the pattern exposure and before the peeling of the support member. 12. The method of claim 11,
and heating the layer formed of the liquid crystal composition after the pattern exposure and before the entire surface exposure. 13. The method according to claim 11 or 12,
At least a part of the organic electroluminescent layer group is a blue-emitting organic electroluminescent layer of the organic electroluminescent layer group.

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