Image projection system

Abstract

The present invention provides an image projection system that makes a projected image easier to see. The image projection system (10A) of the present invention has: an image projection device (12) that emits projection light that is linearly polarized light; a screen (14A) that is irradiated with the projection light emitted from the image projection device (12); and a light-absorbing anisotropic layer (16A) that is disposed between the image projection device (12) and the screen (14A), through which the projection light passes, the light-absorbing anisotropic layer (16A) containing a dichroic substance, and the transmission central axis of the light-absorbing anisotropic layer (16A) being oriented in the direction of the screen (14A).

Description

Technical Field

[0001] This invention relates to an image projection system. Background Technology

[0002] Image projection systems that are widely used to project various images and character information onto a screen.

[0003] For example, in Patent Document 1, a so-called head-up display was developed as one of the in-vehicle displays, which projects various information as images onto the car window glass and transmits it to the driver through an image projection device.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 3-209210 Summary of the Invention

[0007] The technical problem to be solved by the invention

[0008] In image projection systems, it is necessary to make the projected image easier to see.

[0009] Based on their research on the image projection system described in Patent Document 1, the inventors found that the above-mentioned characteristics may not be sufficient and require further improvement.

[0010] In view of the above-mentioned actual situation, the objective of the present invention is to provide an image projection system that makes projected images easier to see.

[0011] means for solving technical problems

[0012] The inventors have discovered that the above-mentioned problems can be solved by the following structure.

[0013] (1) An image projection system having:

[0014] An image projection device that emits projection light as linearly polarized light;

[0015] The screen is illuminated by projection light emitted from the image projection device; and

[0016] An anisotropic light-absorbing layer is positioned between the image projection device and the screen to allow projection light to pass through.

[0017] The light-absorbing anisotropic layer contains dichroic material.

[0018] The transmissivity central axis of the light-absorbing anisotropic layer faces the screen.

[0019] (2) The image projection system according to (1), wherein,

[0020] The area illuminated by the projected light on the screen extends along the direction of the central axis of the light-absorbing anisotropic layer.

[0021] (3) The image projection system according to (1) or (2), wherein,

[0022] The angle between the line connecting the center of the transmission window of the image projection device and the center of the area illuminated by the projection light on the screen and the central axis of the transmittance of the light absorption anisotropic layer is 0 to 30°.

[0023] (4) The image projection system according to any one of (1) to (3), wherein,

[0024] The light-absorbing anisotropic layer contains dichroic substances.

[0025] The content of dichroic material is more than 10.0% by mass relative to the total mass of the light-absorbing anisotropic layer.

[0026] (5) The image projection system according to any one of (1) to (4), wherein,

[0027] The screen includes a reflective layer that reflects the projected light.

[0028] (6) The image projection system according to (5), wherein,

[0029] The reflective layer is a cholesterol-type liquid crystal layer or a multilayer reflective film.

[0030] (7) The image projection system according to any one of (1) to (6) further comprises a B plate disposed between the image projection device and the light-absorbing anisotropic layer for the transmission of projection light.

[0031] (8) The image projection system according to any one of (1) to (7) is used as a vehicle-mounted head-up display.

[0032] (9) The image projection system according to (8), wherein,

[0033] The vehicle's windshield was used as a screen.

[0034] Invention Effects

[0035] According to the present invention, an image projection system is provided that makes projected images easier to see. Attached Figure Description

[0036] Figure 1 This is a schematic diagram illustrating the first embodiment of the image projection system.

[0037] Figure 2 It is a schematic diagram used to illustrate the screen.

[0038] Figure 3 This is a cross-sectional view of an example of a light-absorbing anisotropic layer.

[0039] Figure 4 This is a plan view of an example of a light-absorbing anisotropic layer.

[0040] Figure 5 It is a schematic diagram used to illustrate the orientation of the central axis of transmittance.

[0041] Figure 6 This is a schematic diagram showing a modified example of the first embodiment of the image projection system.

[0042] Figure 7 This is a schematic diagram illustrating a second embodiment of the image projection system.

[0043] Figure 8 This is a schematic diagram illustrating a third embodiment of the image projection system. Detailed Implementation

[0044] The present invention will now be described in detail.

[0045] The following description of the constituent elements is based on a representative embodiment of the present invention, but the present invention is not limited to this embodiment.

[0046] In addition, in this specification, the numerical range indicated by “~” refers to the range including the values ​​recorded before and after “~” as the lower limit and upper limit values.

[0047] In this specification, "(meth)acrylic acid" means "either or both of acrylic acid and methacrylic acid". "(meth)acryloyl" means "either or both of acryloyl and methacryloyl".

[0048] The bonding direction of the divalent group (e.g., -COO-) described in this specification is not particularly limited. For example, if L in XLY is -COO-, and the position bonded to the X side is set as *1 and the position bonded to the Y side is set as *2, then L can be *1-O-CO-*2 or *1-CO-O-*2.

[0049] In this invention, visible light refers to light of electromagnetic waves with wavelengths observable to the naked eye, specifically light in the wavelength range of 380–780 nm. Invisible light refers to light in the wavelength range of less than 380 nm or more than 780 nm.

[0050] As a feature of the image projection system of the present invention, one can cite the fact that an anisotropic light-absorbing layer is disposed between the image projection device and the screen to allow the projection light to pass through.

[0051] As described later, the transmissivity central axis in the light-absorbing anisotropic layer is oriented towards the screen, especially towards the area of ​​the projected light illuminating the screen. Therefore, light not parallel to the transmissivity central axis is easily absorbed from the projected light emitted from the image projection device, and light surrounding the area that brightly illuminates the projected image is also absorbed. As a result, the projected image is easier to visually recognize.

[0052] <First Embodiment>

[0053] Figure 1 A schematic diagram of a first embodiment of the image projection system of the present invention is shown in the figure.

[0054] Figure 1 The image projection system 10A shown includes an image projection device 12, a screen 14A, and a light-absorbing anisotropic layer 16A. For example... Figure 1 The dashed lines in the diagram indicate that most of the projection light emitted from the transmission window 20 of the image projection device 12 passes through the light-absorbing anisotropic layer 16A and illuminates a designated area of ​​the projection light on the screen 14A, where it is reflected. As a result, the observer OB is able to observe a virtual image of the image projected onto the screen 14A. More specifically, in Figure 1 In the image projection system 10A shown, the direction is... Figure 2 Projected light is emitted from a portion of the illumination area 22 on the screen 14A shown, and the projected light is reflected within this illumination area 22. As a result, the observer OB is able to observe the projected image within the illumination area 22 of the projected light on the screen 14A. That is, the illumination area 22 corresponds to the area that projects (reflects) the projected light within the screen 14.

[0055] The black arrows shown in the light-absorbing anisotropic layer 16A indicate the central axis of transmittance. As described later, the central axis of transmittance refers to the direction in which transmittance is highest when the tilt angle (polar angle) and tilt direction (azimuth angle) relative to the normal direction of the light-absorbing anisotropic layer 16A are changed. Therefore, when light travels along this central axis of transmittance, the light is less likely to be absorbed. Conversely, the further the light deviates from the parallel relationship with this central axis of transmittance in the light passing through the light-absorbing anisotropic layer 16A, the more easily it is absorbed.

[0056] exist Figure 1 In the image projection system 10A shown, the projection light emitted from the transmission window 20 of the image projection device 12, as shown by the dashed line, travels in a direction parallel to the central axis of the transmittance of the light-absorbing anisotropic layer 16A. Therefore, this projection light is difficult for the light-absorbing anisotropic layer 16A to absorb.

[0057] In contrast, some of the projection light emitted from the transmission window 20 of the image projection device 12 does not travel in the desired direction, as indicated by the hollow arrow. This light brightly illuminates the area around the observer viewing the projected image, thus reducing the contrast of the projected image and making it difficult for the observer to visually recognize it.

[0058] In the image projection system 10A, the transmissivity central axis of the light-absorbing anisotropic layer 16A faces the screen. More specifically, the screen is arranged in the direction extending from the transmissivity central axis. Therefore, light emitted in a direction different from the desired direction, as indicated by the hollow arrow, can be suppressed from being transmitted to the screen 14A side. As a result, the contrast of the projected image can be improved, making it easier for the observer to visually recognize the projected image.

[0059] exist Figure 1 In the middle, in the direction of extending the central axis of the light absorption anisotropy layer 16A, there is an illumination area 22 of the projected light on the screen 14A.

[0060] Furthermore, in Figure 1 In this invention, the line connecting the center of the transmission window 20 of the image projection device 12 and the center of the projection light illumination area 22 on the screen 14A is parallel to the central axis of the transmittance of the light absorption anisotropic layer 16A. However, the invention is not limited to this parallel arrangement; the angle between the line connecting the center of the transmission window 20 of the image projection device 12 and the center of the projection light illumination area 22 on the screen 14A and the central axis of the transmittance of the light absorption anisotropic layer 16A is preferably 0–30°, more preferably 0–20°, and even more preferably 0–15°. If the angle falls within the above range, the effects of the invention are even better.

[0061] The center of the transmission window 20 of the image projection device 12 refers to the position of the center of the circumscribed circle when the circumscribed circle of the inscribed transmission window 20 is recorded.

[0062] Furthermore, the center of the projection light illumination area 22 on the screen 14A refers to the position of the center of the circumscribed circle when the circumscribed circle of the inscribed illumination area 22 is recorded.

[0063] Furthermore, the angle θ between the transmittance central axis of the light-absorbing anisotropic layer and the normal direction of the surface of the light-absorbing anisotropic layer is not particularly limited, but is preferably 0 to 60°.

[0064] exist Figure 1 In this configuration, the image projection device 12 and the light absorption anisotropic layer 16A are disposed separately, but this is not a limitation; the two can also be in contact. Furthermore, the image projection device 12 and the light absorption anisotropic layer 16A can be bonded together via an adhesive layer or a bonding agent layer.

[0065] The following is a detailed description of each component (image projection device 12, screen 14, light absorption anisotropic layer 16A) constituting the image projection system 10A.

[0066] (Image projection device)

[0067] The structure of the image projection device 12 is not particularly limited as long as it can emit projection light as linearly polarized light, and a known image display device can be used.

[0068] The image projection device 12 may include a polarizer to emit projection light as linearly polarized light.

[0069] The polarizer used in this invention is not particularly limited as long as it is a component that has the function of converting light into specific linearly polarized light, and conventionally known polarizers can be used.

[0070] Examples of polarizers include iodine-based polarizers, dye-based polarizers utilizing dichroic dyes, and polyene-based polarizers. Iodine-based and dye-based polarizers include coated polarizers and stretched polarizers, and either type can be used. As a coated polarizer, a polarizer that orients dichroic organic pigments by utilizing the orientation of liquid crystal compounds is preferred. As a stretched polarizer, a polarizer made by adsorbing iodine or a dichroic dye onto polyvinyl alcohol and then stretching it is preferred.

[0071] In the image projection device 12, there are no particular restrictions on the location of the polarizer; for example, it can be placed on the transmission window 20 of the image projection device 12.

[0072] When the image projection device 12 includes a liquid crystal display device, a polarizer disposed on the visual recognition side of the liquid crystal display device may also be used as the aforementioned polarizer.

[0073] In the image projection device 12, projection light is emitted from the transmission window 20.

[0074] The transmission window 20 can be a simple opening or a transparent portion for the transmission of projected light. The transparent portion can be composed of a glass substrate and a transparent resin film, etc.

[0075] There are no particular restrictions on the shape of the overhead transmission window 20; it can be circular or polygonal.

[0076] There are no particular limitations on the method for changing the imaging distance of the virtual image in the image projection device 12, and well-known methods can be cited.

[0077] As an example of methods for changing the imaging distance of the virtual image in the image projection apparatus 12, examples include methods for moving the image generation surface (screen) (see Japanese Patent Application Publication No. 2017-021302), methods for switching between multiple optical paths with different optical path lengths (see International Publication No. 2015 / 190157), methods for changing the optical path length by inserting and / or moving a mirror, methods for changing the focal length by using a lens group as an imaging lens, methods based on moving the image projection apparatus 12, methods for switching between multiple projectors with different imaging distances of the virtual image, and methods using a zoom lens (International Publication No. WO2010 / 116912), etc.

[0078] As an example of an image projection device 12, one can include an LCOS (Liquid Crystal on Silicon) projector, a laser projector, and a liquid crystal projector (liquid crystal display device).

[0079] (Screen 14A)

[0080] There are no particular limitations on the structure of the screen 14A. For example, a component that reflects the projection light carrying the image and uses the reflected light of the projection light to display the image carried by the projection light as a projected image (e.g., a semi-reflective mirror) can be used. More specifically, a glass plate can be used.

[0081] Furthermore, screen 14A can be laminated glass with an interlayer film disposed between two glass plates. There are no particular limitations on the interlayer film, and materials used to form the interlayer film include, for example, polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer, chlorinated resins, and polyurethane.

[0082] exist Figure 1 In the middle, the screen 14A is flat, and it can have a curved part or the entire surface is curved.

[0083] In screen 14A, such as Figure 2 As shown, only a portion of the area can be used as the illumination area 22 of the projection light emitted from the image projection device 12, or the entire surface can be used as the illumination area.

[0084] Furthermore, as described later, when the image display system of the present invention is used as an in-vehicle head-up display, the windshield of the vehicle can be used as a screen.

[0085] (Light absorption anisotropic layer 16A)

[0086] The light-absorbing anisotropic layer 16A has a transmittance central axis, and the transmittance of light is higher in the direction of the transmittance central axis.

[0087] As described later, the transmittance central axis refers to the axis representing the direction of highest transmittance when measuring transmittance by changing the tilt angle (polar angle) and tilt direction (azimuth angle) relative to the normal direction of the light-absorbing anisotropic layer surface. Specifically, the Mueller matrix at a wavelength of 550 nm was actually measured using an AxoScan OPMF-1 (manufactured by Opto Science, Inc.). More specifically, during the measurement, the azimuth angle of the transmittance central axis tilt was initially found. Then, within the surface containing the normal direction of the light-absorbing anisotropic layer along its azimuth angle (a plane containing the transmittance central axis and orthogonal to the layer surface), the polar angle relative to the normal direction of the light-absorbing anisotropic layer surface was changed by 1° up to -70° to 70°. The Mueller matrix at a wavelength of 550 nm was actually measured, and the transmittance of the light-absorbing anisotropic layer was derived. The direction of highest transmittance was then taken as the transmittance central axis.

[0088] In addition, the transmittance central axis refers to the direction of the absorption axis (long axis direction of the molecule) of the dichroic material contained in the light absorption anisotropic layer.

[0089] The light-absorbing anisotropic layer 16A is not particularly limited in structure as long as it has the aforementioned transmittance central axis, such as... Figure 3 and 4 As shown, it preferably contains dichroic substance D.

[0090] in addition, Figure 3 This is a cross-sectional view of the light absorption anisotropic layer 16A. Figure 4 yes Figure 3 The diagram shows a plan view of the light absorption anisotropic layer 16A. Additionally, Figure 3 yes Figure 4 The sectional view of the image, cut along line A-A.

[0091] exist Figure 3 In the diagram, direction X and direction Z represent the orientation of two mutually orthogonal coordinate axes on the observation plane. Direction Z is parallel to the thickness direction of the light absorption anisotropy layer 16A.

[0092] exist Figure 4 In the diagram, direction X and direction Y represent the orientation of two mutually orthogonal coordinate axes on the observation plane.

[0093] As will be described later, dichroic substance D is a substance that produces a difference in absorption intensity when two linearly polarized lights with electric vectors that are 90° apart are incident on each other.

[0094] In the light-absorbing anisotropic layer 16A, the long axis of the dichroic material D is arranged obliquely relative to the surface of the light-absorbing anisotropic layer 16A.

[0095] More specifically, will Figure 3 and 4The direction of the major axis of the dichroic material D projected onto the surface of the anisotropic light-absorbing layer 16A is parallel to the X-axis (the left-right direction of the paper). Therefore, the X-axis (the left-right direction of the paper) corresponds to the position with the lowest transmittance for linearly polarized light in the in-plane direction of the anisotropic light-absorbing layer 16A. That is, Figure 4 The direction of the hollow dashed arrow shown (left and right on the paper) corresponds to the azimuth angle of the transmissivity center axis tilt.

[0096] And, as Figure 3 As shown, in the light-absorbing anisotropic layer 16A, the dichroic material D is tilted by θ° relative to the normal direction of the light-absorbing anisotropic layer 16A. Therefore, the transmittance central axis of the light-absorbing anisotropic layer 16A is parallel to the X direction and is located in a direction tilted by θ° relative to the normal direction of the surface of the light-absorbing anisotropic layer 16A.

[0097] The angle θ is preferably adjusted so that the angle between the line connecting the center of the transmission window 20 of the image projection device 12 and the center of the projection light illumination area 22 on the screen 14A and the transmissivity central axis of the light absorption anisotropic layer 16A is within a specified range.

[0098] There is no particular limitation on the azimuth angle of the transmittance center axis of the light-absorbing anisotropic layer 16A (the azimuth angle of the tilt of the transmittance center axis). The direction in which the transmittance center axis is orthogonally projected onto the surface of the light-absorbing anisotropic layer 16A (corresponding to the azimuth angle of the tilt of the transmittance center axis) is preferably parallel to the direction of the projected light emitted from the image projection device 12, i.e., the linearly polarized light.

[0099] More specifically, the direction in which the transmittance central axis is projected orthogonally onto the surface of the light-absorbing anisotropic layer corresponds to the direction in which the transmittance central axis TA extends when viewed from the normal direction of the surface of the light-absorbing anisotropic layer. Figure 5 The text is represented by a black line. Figure 5 The hollow arrow indicates the direction of linearly polarized light, such as... Figure 5 As shown, the direction of linearly polarized light is preferably parallel to the extension direction of the black line.

[0100] Furthermore, the transmittance central axis of the light-absorbing anisotropic layer 16A is also equivalent to the orientation of the dichroic material D. In other words, the transmittance central axis of the light-absorbing anisotropic layer 16A is also equivalent to the orientation of the major axis of the dichroic material D.

[0101] Therefore, the central axis of transmittance of the light-absorbing anisotropic layer 16A can also be called the absorption axis of the light-absorbing anisotropic layer 16A.

[0102] Furthermore, when the image display device includes a polarizer, the angle between the direction of the axis that projects the transmittance center axis of the light-absorbing anisotropic layer 16A onto the surface of the light-absorbing anisotropic layer 16 and the absorption axis of the polarizer included in the image display device is preferably 80 to 90°.

[0103] There is no particular limitation on the thickness of the light-absorbing anisotropic layer 16A, which is usually 0.1 to 10 μm.

[0104] Furthermore, as a technique for achieving the desired orientation of the dichroic material D, examples include the fabrication techniques for a polarizer using the dichroic material D and the fabrication techniques for host-guest liquid crystal cells. For instance, the techniques used in the fabrication of the dichroic polarizing element described in Japanese Patent Application Publication No. 11-305036 and Japanese Patent Application Publication No. 2002-090526, and the methods used in the fabrication of the host-guest type liquid crystal display device described in Japanese Patent Application Publication No. 2002-099388 and Japanese Patent Application Publication No. 2016-027387, can also be applied to the fabrication of the light absorption anisotropic layer 16A.

[0105] To prevent changes in the light absorption characteristics of the anisotropic light absorption layer 16A due to the operating environment, it is preferable to fix the orientation of the dichroic material D by forming a chemical bond. For example, the orientation can be fixed by polymerizing the host liquid crystal, the dichroic material D, or a polymerizable component to be added as desired.

[0106] Furthermore, by permeating the dichroic substance D into the polymer film and orienting the dichroic substance along the orientation of the polymer molecules in the polymer film, a light-absorbing anisotropic layer 16A can be fabricated.

[0107] [Dichroic substances]

[0108] In this invention, as described above, a dichroic substance refers to a compound whose absorbance varies with direction. In anisotropic light absorption layers, dichroic substances can be fixed by polymerization.

[0109] There are no particular limitations on dichroic substances. Examples include visible light absorbing substances (dichroic pigments), luminescent substances (fluorescent substances, phosphorescent substances), ultraviolet light absorbing substances, infrared light absorbing substances, nonlinear optical substances, carbon nanotubes, and inorganic substances (such as quantum rods). Conventionally known dichroic substances (preferably dichroic pigments) can be used.

[0110] Specifically, examples include paragraphs

[0067] to

[0071] of Japanese Patent Application Publication No. 2013-228706, paragraphs

[0008] to

[0026] of Japanese Patent Application Publication No. 2013-227532, paragraphs

[0008] to

[0015] of Japanese Patent Application Publication No. 2013-209367, paragraphs

[0045] to

[0058] of Japanese Patent Application Publication No. 2013-14883, paragraphs

[0012] to

[0029] of Japanese Patent Application Publication No. 2013-109090, and Japanese Patent Application Publication No. 2013-101328. Paragraphs

[0009] to

[0017] of Japanese Patent Application Publication No. 2013-037353, paragraphs

[0051] to

[0065] of Japanese Patent Application Publication No. 2012-063387, paragraphs

[0049] to

[0073] of Japanese Patent Application Publication No. Hei 11-305036, paragraphs

[0016] to

[0018] of Japanese Patent Application Publication No. 2001-133630, paragraphs

[0009] to

[0011] of Japanese Patent Application Publication No. 2011-215337, paragraphs

[0030] to

[0169] of Japanese Patent Application Publication No. 2010-10624, and Japanese Patent Application Publication No. 2010-10624. Paragraphs

[0021] to

[0075] of Japanese Announcement No. 2, paragraphs

[0011] to

[0025] of Japanese Announcement No. 2010-215846, paragraphs

[0017] to

[0069] of Japanese Announcement No. 2011-048311, paragraphs

[0013] to

[0133] of Japanese Announcement No. 2011-213610, paragraphs

[0074] to

[0246] of Japanese Announcement No. 2011-237513, paragraphs

[0005] to

[0051] of Japanese Announcement No. 2016-006502, WO2016 / 0 The dichroic substances described in paragraphs

[0005] to

[0041] of Published No. 60173, paragraphs

[0008] to

[0062] of Published No. WO2016 / 136561, paragraphs

[0014] to

[0033] of International Publication No. 2017 / 154835, paragraphs

[0014] to

[0033] of International Publication No. 2017 / 154695, paragraphs

[0013] to

[0037] of International Publication No. 2017 / 195833, and paragraphs

[0014] to

[0034] of International Publication No. 2018 / 164252.

[0111] As a dichroic substance, a dichroic azo dye compound is preferred.

[0112] Dichroic azo dye compounds refer to azo dye compounds whose absorbance varies depending on the direction. Dichroic azo dye compounds may or may not exhibit liquid crystal properties. When a dichroic azo dye compound exhibits liquid crystal properties, it may exhibit either nematic or smectic properties. The preferred temperature range for exhibiting the liquid crystal phase is room temperature (approximately 20–28°C) to 300°C, and more preferably 50–200°C from the viewpoint of operability and manufacturing suitability.

[0113] In this invention, two or more dichroic materials may be used together. For example, from the viewpoint of making the obtained light absorption anisotropic layer close to black, it is preferable to use at least one dichroic material with a maximum absorption wavelength in the range of wavelengths above 370 nm and below 500 nm and at least one dichroic material with a maximum absorption wavelength in the range of wavelengths above 500 nm and below 700 nm.

[0114] As described later, the light-absorbing anisotropic layer can be formed using a composition for forming a light-absorbing anisotropic layer. In the composition for forming a light-absorbing anisotropic layer, the dichroic material may have cross-linking groups. When the dichroic material has cross-linking groups, when the light-absorbing anisotropic layer is formed using the composition for forming a light-absorbing anisotropic layer, the dichroic material in a predetermined orientation state can be immobilized.

[0115] As a crosslinking group, examples include (meth)acryloyl, epoxy, oxetyl and styryl, among which (meth)acryloyl is preferred.

[0116] The content of dichroic material in the light-absorbing anisotropic layer is not particularly limited, but it is mostly 5.0% by mass or more relative to the total mass of the light-absorbing anisotropic layer. From the viewpoint that it is easier to see the projected image (hereinafter, it can also be simply referred to as "the viewpoint that the effect of the present invention is superior"), it is preferably 10.0% by mass or more, more preferably 13.0 to 35.0% by mass, and even more preferably 17.0 to 30.0% by mass.

[0117] [Liquid Crystal Compounds]

[0118] The light-absorbing anisotropic layer preferably contains a liquid crystal compound. This suppresses the precipitation of dichroic substances and allows the dichroic substances to be oriented with a higher degree of orientation.

[0119] As the liquid crystal compound, either a high-molecular-weight liquid crystal compound or a low-molecular-weight liquid crystal compound can be used. From the viewpoint of improving the degree of orientation, a high-molecular-weight liquid crystal compound is preferred. Furthermore, both high-molecular-weight liquid crystal compounds and low-molecular-weight liquid crystal compounds can be used together as the liquid crystal compound.

[0120] Here, "polymer liquid crystal compound" refers to a liquid crystal compound that has repeating units in its chemical structure.

[0121] Here, "low molecular weight liquid crystal compound" refers to a liquid crystal compound that does not have repeating units in its chemical structure.

[0122] Examples of polymeric liquid crystal compounds include, for example, the thermotropic liquid crystal polymer described in Japanese Patent Application Publication No. 2011-237513 and the polymeric liquid crystal compounds described in paragraphs

[0012] to

[0042] of International Publication No. 2018 / 199096.

[0123] As a low-molecular-weight liquid crystal compound, examples include the liquid crystal compounds described in paragraphs

[0072] to

[0088] of Japanese Patent Application Publication No. 2013-228706, among which, liquid crystal compounds exhibiting smectic properties are preferred.

[0124] From the perspective of achieving a higher degree of orientation of dichroic materials, liquid crystal compounds preferably include polymeric liquid crystal compounds containing repeating units (hereinafter also simply referred to as "repeating units (1)") represented by the following formula (1).

[0125] [Chemical Formula 1]

[0126]

[0127] In the above formula (1), P1 represents the main chain of repeating units, L1 represents a single bond or a divalent linker, SP1 represents a spacer group, M1 represents a mesocrystalline group, and T1 represents a terminal group.

[0128] As the main chain of the repeating unit represented by P1, specifically, for example, groups represented by the following formulas (P1-A) to (P1-D) can be cited, wherein, from the viewpoint of the diversity of monomers that can be used as raw materials and ease of processing, groups represented by the following formula (P1-A) are preferred.

[0129] [Chemical Formula 2]

[0130]

[0131] In the above formulas (P1-A) to (P1-D), "*" indicates the bonding position with L1 in the above formula (1).

[0132] In the above equations (P1-A) to (P1-D), R 1 R 2 R 3 and R 4Each of the above-mentioned groups independently represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. The alkyl group can be a straight-chain or branched alkyl group, or it can be an alkyl group having a cyclic structure (cycloalkyl). Furthermore, the alkyl group preferably has 1 to 5 carbon atoms.

[0133] The group represented by the above formula (P1-A) is preferably a unit of a portion of the structure of a poly(meth)acrylate obtained by polymerization of (meth)acrylate.

[0134] The group represented by the above formula (P1-B) is preferably an ethylene glycol unit formed by ring-opening polymerization of the epoxy group of a compound having an epoxy group.

[0135] The group represented by the above formula (P1-C) is preferably a propylene glycol unit formed by ring-opening polymerization of an oxetane compound having an oxetane.

[0136] The group represented by the above formula (P1-D) is preferably a siloxane unit of a polysiloxane obtained by polycondensation of a compound having at least one of alkoxysilyl and silanol groups. Here, as a compound having at least one of alkoxysilyl and silanol groups, an example can be a compound having the formula SiR 14 (OR 15 Compounds containing a group represented by )2-. In the formula, R 14 R in (P1-D) 14 Multiple Rs with the same meaning 15 Each can be independently represented as either a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0137] In the above formula (1), L1 is a single bond or a divalent linker.

[0138] Examples of divalent linker bases represented by L1 include -C(O)O-, -O-, -S-, and -C(O)NR. 3 -, -SO2- and -NR 3 R 4 - In the formula, R 3 and R 4 Each can be independently represented by a hydrogen atom or an alkyl group having 1 to 6 carbon atoms that may have substituents.

[0139] When P1 is a group represented by formula (P1-A), from the perspective of increasing the orientation degree of the dichroic material, L1 is preferably a group represented by -C(O)O-.

[0140] When P1 is a group represented by formulas (P1-B) to (P1-D), from the perspective of increasing the orientation degree of dichroic substances, L1 is preferably a single bond.

[0141] In the above formula (1), from the perspective of easy liquid crystal properties or availability of raw materials, the spacer group represented by SP1 preferably includes at least one structure selected from the group consisting of ethylene oxide structure, propylene oxide structure, polysiloxane structure and fluorinated alkylene structure.

[0142] Among them, the oxyethylene structure represented by SP1 is preferably composed of *-(CH2-CH2O). n1 -* indicates a group. In the formula, n1 represents an integer from 1 to 20, and * represents the bonding position with L1 or M1 in the above formula (1). From the viewpoint of increasing the orientation degree of dichroic substances, n1 is preferably an integer from 2 to 10, more preferably an integer from 2 to 4, and even more preferably 3.

[0143] Furthermore, from the viewpoint that the orientation degree of dichroic substances becomes higher, the oxypropylene structure represented by SP1 is preferably *-(CH(CH3)-CH2O). n2 -* represents the group. In the formula, n2 represents an integer from 1 to 3, and * represents the bonding position with L1 or M1.

[0144] Furthermore, from the viewpoint that the orientation degree of dichroic materials becomes higher, the polysiloxane structure represented by SP1 is preferably *-(Si(CH3)2-O). n3 -* represents the group. In the formula, n3 represents an integer from 6 to 10, and * represents the bonding position with L1 or M1.

[0145] Furthermore, from the viewpoint that the orientation degree of dichroic substances becomes higher, the fluorinated alkylene structure represented by SP1 is preferably *-(CF2-CF2). n4 -* represents the group. In the formula, n4 represents an integer from 6 to 10, and * represents the bonding position with L1 or M1.

[0146] In the above formula (1), M1 represents the mesocrystalline group, which is the group that represents the main framework of the liquid crystal molecules that contributes to the formation of liquid crystals. Liquid crystal molecules exhibit liquid crystal properties in an intermediate state (intermediate phase) between the crystalline state and the isotropic liquid state. There are no particular limitations on the mesocrystalline group. For example, one can refer to "Flussige Kristalle in Tabellen II" (VEBDeutsche Verlag fur Grundstoff Industrie, Leipzig, 1984), especially the records on pages 7 to 16, and the records in Liquid Crystal Handbook Editorial Committee, Liquid Crystal Handbook (Maruzen, 2000), especially the records in Chapter 3.

[0147] As a mesocrystalline group, it is preferred, for example, to have at least one cyclic structure selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups and alicyclic groups.

[0148] From the perspective of increasing the orientation degree of dichroic substances, the mesocrystalline group preferably has aromatic hydrocarbon groups, more preferably has 2 to 4 aromatic hydrocarbon groups, and even more preferably has 3 aromatic hydrocarbon groups.

[0149] As a mesocrystalline group, considering the manifestation of liquid crystal properties, the adjustment of liquid crystal phase transition temperature, the availability of raw materials and the applicability of synthesis, as well as the higher orientation degree of dichroic materials, the group represented by the following formula (M1-A) or the group represented by the following formula (M1-B) is preferred, and the group represented by formula (M1-B) is more preferred.

[0150] [Chemical Formula 3]

[0151]

[0152] In formula (M1-A), A1 is a divalent group selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups. These groups may be substituted with substituents such as alkyl, fluorinated alkyl, and alkoxy groups.

[0153] The divalent group represented by A1 is preferably a 4- to 6-membered ring. Furthermore, the divalent group represented by A1 can be a monocyclic ring or a fused ring.

[0154] * indicates the bonding position with SP1 or T1.

[0155] Examples of divalent aromatic hydrocarbon groups represented by A1 include phenylene, naphthylene, fluorene-diyl, anthracene-diyl, and tetraphenyl-diyl. From the perspective of the diversity of mesocrystalline framework design or the availability of raw materials, phenylene or naphthylene is preferred, and phenylene is more preferred.

[0156] The divalent heterocyclic group represented by A1 can be either aromatic or non-aromatic. Considering the higher degree of orientation of dichroic substances, a divalent aromatic heterocyclic group is preferred.

[0157] Examples of atoms other than carbon that constitute a divalent aromatic heterocyclic group include nitrogen, sulfur, and oxygen atoms. When an aromatic heterocyclic group has multiple atoms that constitute the ring besides carbon, these atoms can be the same or different.

[0158] Specific examples of divalent aromatic heterocyclic groups include pyridinyl (pyridine-diyl), pyridazinyl (pyridinyl), imidazole-diyl, thiophenyl (thiophene-diyl), quinolineyl (quinoline-diyl), isoquinolineyl (isoquinoline-diyl), oxazole-diyl, thiazole-diyl, oxadiazole-diyl, benzothiazole-diyl, benzothiadiazole-diyl, phthalimide-diyl, thienothiazole-diyl, thiazonothiazole-diyl, thienothiphene-diyl, and thienooxazole-diyl, etc.

[0159] Specific examples of the divalent alicyclic group represented by A1 include cyclopentylene and cyclohexylene.

[0160] In the formula (M1-A), a1 represents an integer from 1 to 10. When a1 is 2 or higher, multiple A1 values ​​can be the same or different.

[0161] In formula (M1-B), A2 and A3 are each independently a divalent group selected from the group consisting of aromatic hydrocarbon groups, heterocyclic groups, and alicyclic groups. Specific examples and preferred embodiments of A2 and A3 are the same as A1 in formula (M1-A), therefore their description is omitted.

[0162] In formula (M1-B), a2 represents an integer from 1 to 10. When a2 is 2 or more, multiple A2s can be the same or different, multiple A3s can be the same or different, and multiple LA1s can be the same or different. Considering that the orientation degree of dichroic materials becomes higher, a2 is preferably an integer of 2 or more, and more preferably 2.

[0163] In formula (M1-B), when a2 is 1, LA1 is a divalent linker. When a2 is 2 or more, the plurality of LA1s are independently either single bonds or divalent linkers, and at least one of the plurality of LA1s is a divalent linker. When a2 is 2, considering that the orientation degree of the dichroic material becomes higher, it is preferable that one of the two LA1s is a divalent linker and the other is a single bond.

[0164] In equation (M1-B), examples of divalent linkers represented by LA1 include -O- and -(CH2). g -、-(CF2) g -、-Si(CH3)2-、-(Si(CH3)2O) g -、-(OSi(CH3)2) g-(g represents an integer from 1 to 10.), --N(Z)-, -C(Z)=C(Z')-, -C(Z)=N-, -C(Z)2-C(Z')2-, -C(O)-, -OC(O )-, -OC(O)O-, -N(Z)C(O)-, -C(Z)=C(Z')-C(O)O-, -C(Z)=N-, -C(Z)=C(Z')-C(O)N(Z”) -, -C(Z)=C(Z')-C(O)-S-, -C(Z)=NN=C(Z')- (Z, Z', and Z” independently represent a hydrogen atom, a C1-C4 alkyl group, a cycloalkyl group, an aryl group, a cyano group, or a halogen atom, respectively.), -C≡C-, -N=N-, -S-, -S(O)-, -S(O)(O)-, -(O)S(O)O-, -O(O)S(O)O-, and -SC(O), etc. Among these, -C(O)O- is preferred from the perspective of increasing the orientation degree of dichroic substances. LA1 can be a group formed by combining two or more of these groups.

[0165] In the above formula (1), examples of terminal groups represented by T1 include hydrogen atoms, halogen atoms, cyano groups, nitro groups, hydroxyl groups, alkyl groups with 1 to 10 carbon atoms, alkoxy groups with 1 to 10 carbon atoms, alkylthio groups with 1 to 10 carbon atoms, alkoxycarbonyloxy groups with 1 to 10 carbon atoms, alkoxycarbonyl groups with 1 to 10 carbon atoms (ROC(O)-: R is alkyl), acyloxy groups with 1 to 10 carbon atoms, acylamino groups with 1 to 10 carbon atoms, alkoxycarbonylamino groups with 1 to 10 carbon atoms, sulfonylamino groups with 1 to 10 carbon atoms, aminosulfonyl groups with 1 to 10 carbon atoms, carbamoyl groups with 1 to 10 carbon atoms, thionyl groups with 1 to 10 carbon atoms, urea groups with 1 to 10 carbon atoms, and groups containing (meth)acryloyloxy groups. Examples of groups containing (meth)acryloyloxy groups include those represented by -LA (L represents a single bond or linker. Specific examples of linkers are the same as L1 and SP1 described above. A can be a group represented by (meth)acryloyloxy).

[0166] From the perspective of increasing the orientation degree of dichroic substances, T1 is preferably an alkoxy group with 1 to 10 carbon atoms, more preferably an alkoxy group with 1 to 5 carbon atoms, and even more preferably a methoxy group.

[0167] These terminal groups can be further replaced by these groups or polymeric groups as described in Japanese Patent Application Publication No. 2010-244038.

[0168] From the viewpoint that the adhesion with adjacent layers becomes better and the cohesive force as a membrane is improved, T1 is preferably a polymeric group.

[0169] There are no particular limitations on the polymerizable groups, but polymerizable groups capable of free radical polymerization or cationic polymerization are preferred.

[0170] As a free radical polymerizable group, commonly known free radical polymerizable groups can be used. Examples of preferred free radical polymerizable groups include acryloyl and methacryloyl. In this case, acryloyl is known to generally have a fast polymerization rate, and from the viewpoint of improving productivity, acryloyl is preferred, but methacryloyl can also be used as a polymerizable group.

[0171] As the cationic polymerizable group, commonly known cationic polymerizable groups can be used. Specifically, examples include alicyclic ether groups, cyclic acetal groups, cyclic lactone groups, cyclic thioether groups, spirocyclic orthoester groups, and ethyleneoxy groups. Among these, alicyclic ether groups or ethyleneoxy groups are preferred, and epoxy groups, oxetyl groups, or ethyleneoxy groups are even more preferred.

[0172] From the perspective of achieving a higher degree of orientation in dichroic materials, the weight-average molecular weight (Mw) of the polymeric liquid crystal compound containing the repeating unit represented by the above formula (1) is preferably 1,000 to 500,000, more preferably 2,000 to 300,000. If the Mw of the polymeric liquid crystal compound is within the above range, the polymeric liquid crystal compound is easier to process.

[0173] In particular, from the perspective of suppressing cracks during coating, the weight-average molecular weight (Mw) of the polymer liquid crystal compound is preferably 10,000 or more, and more preferably 10,000 to 300,000.

[0174] Furthermore, from the viewpoint of the temperature range of orientation, the weight-average molecular weight (Mw) of the polymer liquid crystal compound is preferably less than 10,000, more preferably 2,000 or more and less than 10,000.

[0175] In this invention, the weight-average molecular weight and number-average molecular weight are values ​​determined by gel permeation chromatography (GPC).

[0176] • Solvent (eluent): N-methylpyrrolidone

[0177] • Device Name: TOSOH HLC-8220GPC

[0178] • String: Connect 3 TOSOH TSKgelSuperAWM-H (6mm×15cm) tubes for use.

[0179] Column temperature: 25℃

[0180] • Sample concentration: 0.1% by mass

[0181] • Flow rate: 0.35 ml / min

[0182] • Calibration curve: The calibration curve was obtained using seven samples of TSK standard polystyrene manufactured by TOSOH with Mw = 2,800,000 to 1,050 (Mw / Mn = 1.03 to 1.06).

[0183] As a liquid crystal compound, it can be a polymer of a liquid crystal compound having polymerizable groups (polymeric liquid crystal compound).

[0184] When the light-absorbing anisotropic layer contains a liquid crystal compound, from the viewpoint of achieving better results in this invention, the content of the liquid crystal compound relative to the total mass of the light-absorbing anisotropic layer is preferably 50 to 99% by mass, more preferably 75 to 90% by mass.

[0185] [Other ingredients]

[0186] The light-absorbing anisotropic layer may also contain other components besides those mentioned above. Examples of such other components include, for instance, vertical alignment agents and leveling agents.

[0187] Boric acid compounds and onium salts can be cited as vertical orientation agents.

[0188] As a boric acid compound, the compound represented by formula (A) is preferred.

[0189] Formula (A)

[0190] [Chemical Formula 4]

[0191]

[0192] In formula (A), R 1 and R 2 Each of these can be independently represented as a hydrogen atom, a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroatom-containing cyclic group.

[0193] R 3 This indicates a substituent containing a (meth)acrylic acid group.

[0194] As a specific example of a boric acid compound, one can cite the boric acid compound represented by general formula (I) described in paragraphs

[0023] to

[0032] of Japanese Patent Application Publication No. 2008-225281.

[0195] As an onium salt, the compound represented by formula (B) is preferred.

[0196] Formula (B)

[0197] [Chemical Formula 5]

[0198]

[0199] In formula (B), ring A represents a quaternary ammonium ion composed of a nitrogen-containing heterocycle. - Indicates anion. L 1 This represents a divalent linker. L 2 Represents a single bond or a divalent linker. Y 1 The symbol "Z" indicates a divalent linker with a 5- or 6-membered ring as part of the structure. The symbol "P" indicates a divalent linker with 2–20 alkylene groups as part of the structure. 1 and P 2 Each of these represents a monovalent substituent that has a polymerizable alkene unsaturated bond.

[0200] Specific examples of onium salts include those described in paragraphs

[0052] to

[0058] of Japanese Patent Application Publication No. 2012-208397, those described in paragraphs

[0024] to

[0055] of Japanese Patent Application Publication No. 2008-026730, and those described in Japanese Patent Application Publication No. 2002-037777.

[0201] When the light-absorbing anisotropic layer contains a liquid crystal compound and a vertical alignment agent, the content of the vertical alignment agent relative to the total mass of the liquid crystal compound is preferably 0.1 to 400% by mass, more preferably 0.5 to 350% by mass.

[0202] Vertical alignment agents can be used alone or in combination of two or more. When using two or more vertical alignment agents, it is preferable that their combined dosage is within the range described above.

[0203] The light-absorbing anisotropic layer may also contain a leveling agent. When the composition for forming the light-absorbing anisotropic layer (light-absorbing anisotropic layer) described later contains a leveling agent, the roughness of the surface caused by the drying wind applied to the surface of the light-absorbing anisotropic layer is suppressed, thereby further homogenizing the dichroic material.

[0204] There are no particular restrictions on leveling agents, but leveling agents containing fluorine atoms (fluorine-based leveling agents) or leveling agents containing silicon atoms (silicone-based leveling agents) are preferred, and fluorine-based leveling agents are even more preferred.

[0205] Examples of fluorinated leveling agents include fatty acid esters of polycarboxylic acids in which a portion of the fatty acid is replaced by a fluorinated alkyl group, and polyacrylates with fluorinated substituents.

[0206] Specific examples of leveling agents include the compounds illustrated in paragraphs

[0046] to

[0052] of Japanese Patent Application Publication No. 2004-331812 and the compounds described in paragraphs

[0038] to

[0052] of Japanese Patent Application Publication No. 2008-257205.

[0207] When the light-absorbing anisotropic layer contains a liquid crystal compound and a leveling agent, the content of the leveling agent relative to the total mass of the liquid crystal compound is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass.

[0208] Leveling agents can be used alone or in combination of two or more. When using two or more leveling agents, it is preferable that their combined dosage is within the range mentioned above.

[0209] [Composition for forming anisotropic light-absorbing layers]

[0210] The light-absorbing anisotropic layer is preferably formed using a composition for forming a light-absorbing anisotropic layer containing a dichroic substance.

[0211] The composition for forming anisotropic light-absorbing layers preferably includes, in addition to dichroic substances, liquid crystal compounds and solvents described later, and may further include other components mentioned above.

[0212] Examples of dichroic substances that can be included in a composition for forming anisotropic light-absorbing layers include dichroic substances that can be included in anisotropic light-absorbing layers.

[0213] The content of the dichroic substance relative to the total solid content of the composition for forming the light-absorbing anisotropic layer is preferably the same as the content of the dichroic substance relative to the total mass of the light-absorbing anisotropic layer.

[0214] Here, "total solids content in the composition for forming anisotropic light-absorbing layers" refers to components other than solvents. Specific examples of solids content include dichroic substances, liquid crystal compounds, and the other components mentioned above.

[0215] The liquid crystal compound and other components that may be included in the composition for forming the light-absorbing anisotropic layer are the same as those that may be included in the liquid crystal compound and other components in the light-absorbing anisotropic layer.

[0216] Examples of liquid crystal compounds include the aforementioned polymeric liquid crystal compounds and liquid crystal compounds with polymerizable groups.

[0217] Preferably, the content of liquid crystal compound and other components relative to the total solid content of the composition for forming the light absorption anisotropic layer is the same as the content of liquid crystal compound and other components relative to the total mass of the light absorption anisotropic layer.

[0218] From an operational point of view, the composition for forming anisotropic light-absorbing layers preferably contains a solvent.

[0219] Examples of solvents include ketones, ethers, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, halogenated carbons, esters, alcohols, cellosols, cellosol acetates, sulfoxides, amides, and heteroatom-containing cyclic compounds, as well as water.

[0220] These solvents can be used alone or in combination with two or more.

[0221] Among these solvents, organic solvents are preferred, and halogenated carbons or ketones are more preferred.

[0222] When the composition for forming anisotropic light-absorbing layers contains a solvent, the solvent content relative to the total mass of the composition for forming anisotropic light-absorbing layers is preferably 80 to 99% by mass, more preferably 83 to 97% by mass, and even more preferably 85 to 95% by mass.

[0223] The composition for forming anisotropic light-absorbing layers may contain a polymerization initiator.

[0224] There are no particular limitations on the polymerization initiator, but photosensitive compounds, i.e., photopolymerization initiators, are preferred.

[0225] Commercially available photopolymerization initiators can also be used, such as Irgacure-184, Irgacure-907, Irgacure-369, Irgacure-651, Irgacure-819, Irgacure-OXE-01, and Irgacure-OXE-02 manufactured by BASF.

[0226] Polymerization initiators can be used alone or in combination with two or more.

[0227] When the composition for forming anisotropic light-absorbing layers contains a polymerization initiator, the content of the polymerization initiator relative to the total solid content of the composition for forming anisotropic light-absorbing layers is preferably 0.01 to 30% by mass, more preferably 0.1 to 15% by mass.

[0228] [Method for manufacturing anisotropic light-absorbing layers]

[0229] There are no particular limitations on the method for manufacturing the light-absorbing anisotropic layer. From the viewpoint of increasing the orientation degree of the dichroic material, a method comprising the following steps in sequence (hereinafter also referred to as "this manufacturing method") is preferred: a step of coating a coating film by coating a light-absorbing anisotropic layer forming composition comprising a dichroic material and a liquid crystal compound onto an alignment film (hereinafter also referred to as "coating film forming step"); and a step of aligning the liquid crystal components contained in the above-mentioned coating film (hereinafter also referred to as "alignment step").

[0230] In addition, the liquid crystal component not only includes the aforementioned liquid crystal compound, but also includes dichroic substances with liquid crystal properties.

[0231] The following is a description of each process.

[0232] The coating film formation process is a process of coating the above-mentioned light absorption anisotropic layer formation composition onto an alignment film to form a coating film.

[0233] By using a light-absorbing anisotropic layer forming composition containing the above-mentioned solvent, or by using a light-absorbing anisotropic layer forming composition that has been molten into a liquid state by heating or the like, the light-absorbing anisotropic layer forming composition can be easily coated onto an alignment film.

[0234] Coating methods for compositions used to form anisotropic light-absorbing layers include known methods such as roller coating, gravure printing, spin coating, wire-wound bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spray coating, and inkjet coating.

[0235] The alignment film can be any film as long as it is a film in which the liquid crystal component contained in the composition for forming anisotropic light absorption layer is oriented.

[0236] Alignment films can be formed by methods such as friction treatment of the film surface with organic compounds (preferably polymers), oblique evaporation of inorganic compounds, formation of a layer with microgrooves, or accumulation of organic compounds (e.g., ω-trisicosaccharide, di(octadecyl)methylammonium chloride, methyl stearate) based on the Langmuir-Blodgett process (LB film). Furthermore, alignment films that generate alignment functions by applying an electric field, a magnetic field, or light irradiation are also known. In this invention, from the viewpoint of ease of controlling the pretilt angle of the alignment film, an alignment film formed by friction treatment is preferred; from the viewpoint of alignment uniformity, a photo-alignment film formed by light irradiation is also preferred.

[0237] As a photoalignment film, a photoalignment film containing azo dyes or polyvinyl cinnamate is used.

[0238] When ultraviolet light is irradiated from an angled direction relative to the normal direction of the light-alignment layer, an anisotropy with an angle relative to the normal direction of the light-alignment layer is generated, causing the light-absorbing anisotropic layer to align on it, thereby enabling the dichroic substances in the light-absorbing anisotropic layer to align.

[0239] Furthermore, liquid crystal layers, such as liquid crystal layers that allow liquid crystal compounds to be mixed and aligned, can also be used as alignment films.

[0240] The alignment process is a process of aligning the liquid crystal components (especially dichroic substances) contained in the coating film. It is understood that in the alignment process, the dichroic substance is aligned along the liquid crystal compound that is oriented through the alignment film.

[0241] The orientation process may include a drying process. This drying process removes components such as solvents from the coated film. The drying process can be performed by placing the coated film at room temperature for a specified time (e.g., natural drying), or by heating and / or air supply.

[0242] The orientation process preferably includes heat treatment. As a result, the dichroic substances contained in the coated film are further oriented, and the degree of orientation of the dichroic substances is further increased.

[0243] From the viewpoint of manufacturing applicability, the heat treatment is preferably 10 to 250°C, more preferably 25 to 190°C. Furthermore, the heating time is preferably 1 to 300 seconds, more preferably 1 to 60 seconds.

[0244] The orientation process can include a cooling process performed after the heat treatment. The cooling process involves cooling the heated coating film to approximately room temperature (20–25°C). This further fixes the orientation of the dichroic substances contained in the coating film, and increases the degree of orientation of the dichroic substances. There are no particular limitations on the cooling method; it can be implemented using known methods.

[0245] Through the above processes, the light absorption anisotropic layer of the present invention can be obtained.

[0246] This manufacturing method may include a step of curing the light-absorbing anisotropic layer after the above-described orientation step (hereinafter also referred to as the "curing step").

[0247] The curing process can be carried out, for example, by heating and / or light exposure (exposure). Preferably, the curing process is carried out by light exposure.

[0248] The light source used for curing can be various light sources such as infrared light, visible light, or ultraviolet light, with ultraviolet light being preferred. Furthermore, during curing, ultraviolet light can be irradiated while heating is being performed, or ultraviolet light can be irradiated through a filter that transmits only a specific wavelength.

[0249] Furthermore, exposure can be performed under a nitrogen atmosphere. When curing the light-absorbing anisotropic layer via free radical polymerization, polymerization hindrance caused by oxygen can be reduced, therefore exposure under a nitrogen atmosphere is preferred.

[0250] In addition, Figure 1 In this case, the light is emitted from the image projection device 12 in a direction that is tilted towards the projection light, but the present invention is not limited to this method, such as... Figure 6As shown, it can also be a method of projecting light from the image projection device 12 in a vertical direction.

[0251] Figure 6 The image projection system 10B shown includes an image projection device 12, a screen 14A, and a light absorption anisotropic layer 16B disposed between the image projection device 12 and the screen 14A. Figure 6 As shown, the projection light emitted vertically from the image projection device 12 is reflected by the light-absorbing anisotropic layer 16B onto the area of ​​the projection light irradiated on the screen 14A. As a result, the observer OB is able to observe a virtual image of the image projected onto the screen 14A.

[0252] In the light-absorbing anisotropic layer 16B, such as Figure 6 As indicated by the black arrow, the central axis of transmittance extends parallel to the direction of the projected light's travel. As a result, a result similar to... Figure 1 The image projection system 10A shown has the same effect.

[0253] <Second Implementation>

[0254] Figure 7 A schematic diagram of a second embodiment of the image projection system of the present invention is shown in the figure.

[0255] Figure 7 The image projection system 10C shown has an image projection device 12, a screen 14B and a light absorption anisotropic layer 16A.

[0256] The image projection system 10C of the second embodiment has the same components as the image projection system 10A of the first embodiment, except that it has a screen 14B instead of a screen 14A. The same components are labeled with the same symbols and their descriptions are omitted. The following mainly describes the way the screen 14B is used.

[0257] The screen 14B has a support 30 and a reflective layer 32 disposed on the support 30.

[0258] The reflective layer 32 has the function of reflecting the projection light emitted from the image projection device 12.

[0259] The support 30 and the reflective layer 32 will be described in detail below.

[0260] (Support 30)

[0261] The support 30 is a component that supports the reflective layer 32.

[0262] There are no particular limitations on the type of support 30, and known supports can be used. In particular, a transparent support is preferred. Furthermore, a transparent support refers to a support with a visible light transmittance of 60% or more, preferably 80% or more, and more preferably 90% or more.

[0263] The support 30 can be a glass substrate or a resin substrate, preferably a glass substrate.

[0264] (Reflective layer)

[0265] The reflective layer 32 has the function of reflecting the projection light emitted from the image projection device 12, and its structure is not particularly limited.

[0266] From the viewpoint of achieving better results in this invention, the reflective layer 32 is preferably a cholesterol-type liquid crystal layer or a multilayer reflective film.

[0267] Cholesterol-type liquid crystal layers are layers formed by fixing a cholesterol-type liquid crystal phase.

[0268] Cholesterol-type liquid crystal phases exhibit wavelength-selective reflectivity, displaying selective reflectivity at specific wavelengths.

[0269] The selective reflection center wavelength λ of a cholesterol-type liquid crystal phase depends on the spacing P (equal to the period of the helical structure) of the helical structure within the cholesterol-type liquid crystal phase and follows the relationship between the average refractive index n of the sterol-type liquid crystal phase and λ = n × P. Therefore, the selective reflection center wavelength can be adjusted by regulating the spacing of this helical structure. The spacing of a cholesterol-type liquid crystal phase depends on the type or concentration of the chiral reagent used with the liquid crystal compound; therefore, the desired spacing can be obtained by adjusting these.

[0270] Furthermore, the half-value width Δλ (nm) of the selective reflection band (circularly polarized light reflection band) exhibited by the selective reflection depends on the refractive index anisotropy Δn of the cholesterol-type liquid crystal phase and the helical spacing P, following the relationship Δλ = Δn × P. Therefore, the width of the selective reflection band can be controlled by adjusting the refractive index anisotropy Δn of the cholesterol-type liquid crystal phase. The refractive index anisotropy Δn can be adjusted by the type and mixing ratio of the liquid crystal compound forming the reflective layer 32, as well as the temperature at which the orientation is fixed.

[0271] The methods for determining the direction and spacing of the spirals can be found in "Introduction to Liquid Crystal Chemistry Experiments" edited by the Japan Liquid Crystal Society, published by Sigma in 2007, page 46, and "Liquid Crystal Handbook" edited by Maruzen, the editorial committee of the Liquid Crystal Handbook, page 196.

[0272] The reflected light from a cholesterol-type liquid crystal phase is circularly polarized. Whether the reflected circularly polarized light is right-handed or left-handed depends on the direction of the helical twist of the cholesterol-type liquid crystal phase. Based on the selective reflection of circularly polarized light from a cholesterol-type liquid crystal phase, when the helical twist direction is right-handed, it reflects right-handed circularly polarized light; when the helical twist direction is left-handed, it reflects left-handed circularly polarized light.

[0273] The reflective layer 32 can be a cholesterol-type liquid crystal layer that reflects right-handed circularly polarized light, or it can be a cholesterol-type liquid crystal layer that reflects left-handed circularly polarized light. Alternatively, the reflective layer 32 can also have a reflective layer composed of a cholesterol-type liquid crystal layer that reflects right-handed circularly polarized light and a reflective layer composed of a cholesterol-type liquid crystal layer that reflects left-handed circularly polarized light.

[0274] The rotation direction of the cholesterol-type liquid crystal phase can be adjusted according to the type of liquid crystal compound forming the reflective layer 32 and / or the type of chiral reagent added.

[0275] To broaden the wavelength range of reflected light and the wavelength region of cut-off light, this can be achieved by sequentially stacking layers that shift the selected reflection wavelength λ. Furthermore, techniques for expanding the wavelength range are also known by periodically changing the spiral spacing within the layers, a method known as the spacing gradient method. Specifically, methods described in Nature 378, 467-469 (1995), Japanese Patent Application Publication No. 6-281814, and Japanese Patent Publication No. 4990426, among others, are cited.

[0276] The structure of a fixed cholesterol-type liquid crystal phase only needs to maintain the orientation of the liquid crystal compound that becomes a cholesterol-type liquid crystal phase. Typically, the polymerizable liquid crystal compound is set in the orientation state of a cholesterol-type liquid crystal phase, and then polymerized and cured by ultraviolet (UV) irradiation or heating to form a non-flowing layer, thus becoming a structure that will not change its orientation due to external magnetic field or external force.

[0277] Furthermore, in structures that fix the cholesterol-type liquid crystal phase, maintaining the optical properties of the cholesterol-type liquid crystal phase is sufficient, and the liquid crystal compound may not exhibit liquid crystal properties. For example, polymerizable liquid crystal compounds can lose their liquid crystal properties by undergoing a curing reaction to increase their molecular weight.

[0278] As a material for forming a cholesterol-type liquid crystal layer by fixing a cholesterol-type liquid crystal phase, an example can be a liquid crystal composition containing a liquid crystal compound. The liquid crystal compound is preferably a polymerizable liquid crystal compound.

[0279] The liquid crystal composition containing the liquid crystal compound for forming the cholesterol-type liquid crystal layer preferably also contains a surfactant. Furthermore, the liquid crystal composition for forming the cholesterol-type liquid crystal layer may also contain chiral agents, polymerization initiators, and orientation agents, etc.

[0280] Multilayer reflective films are films that have the property of reflecting light in a specific wavelength range by stacking multiple layers with different refractive indices.

[0281] As a multilayer reflective film, it is preferably a film formed by alternating layers of low-refractive-index material and high-refractive-index material.

[0282] The layers that make up the multilayer reflective film can be organic layers made of organic materials or inorganic layers made of inorganic materials.

[0283] When the reflective layer 32 selectively reflects green light while transmitting other light, the image projection system 10C displays a green monochrome image. When the reflective layer 32 selectively reflects red light while transmitting other light, the image projection system 10C displays a red monochrome image. When the reflective layer 32 selectively reflects blue light while transmitting other light, the image projection system 10C displays a blue monochrome image.

[0284] Furthermore, when a stack of a green light reflective layer, a red light reflective layer, and a blue light reflective layer is used as the reflective layer 32, the image projection system 10C displays a full-color image.

[0285] exist Figure 7 In this invention, a reflective layer 32 is provided on the entire surface of the support 30. However, the invention is not limited to this method, and the reflective layer 32 may also be provided only in a portion of the surface of the support 30. In particular, it is preferable to provide the reflective layer 32 in the irradiation area that irradiates the projection light emitted from the image projection device 12.

[0286] Furthermore, in Figure 7 In this invention, a reflective layer 32 is provided on one surface of the support 30, but the invention is not limited to this method. The reflective layer 32 can also be sandwiched between two supports 30.

[0287] <Third Implementation>

[0288] Figure 8 A schematic diagram of a third embodiment of the image projection system of the present invention is shown in the figure.

[0289] Figure 8 The image projection system 10D shown includes an image projection device 12, a screen 14B, a light absorption anisotropic layer 16A, and a B plate 18. The B plate 18 is disposed between the image projection device 12 and the screen 14B to allow projection light to pass through.

[0290] The image projection system 10D of the third embodiment has the same components as the image projection system 10C of the second embodiment, except that it has a B plate 18. The same components are labeled with the same symbols and their descriptions are omitted. The following mainly describes the manner of the B plate 18.

[0291] (B board 18)

[0292] As a B-plate 18, it has a positive B-plate and a negative B-plate.

[0293] When the refractive index in the slow axis direction (the direction with the largest refractive index in the plane) is set as nx, the refractive index in the direction orthogonal to the slow axis in the plane is set as ny, and the refractive index in the thickness direction is set as nz, the positive B plate satisfies the relationship of equation (1), and the negative B plate satisfies the relationship of equation (2).

[0294] Equation (1) nz>nx>ny

[0295] Equation (2) nx>ny>nz

[0296] The thickness retardation of the positive B plate is negative, while the thickness retardation of the negative B plate is positive.

[0297] There is no particular limitation on the in-plane delay of plate B18 at a wavelength of 550nm, but from the viewpoint of better performance of the present invention, it is preferred to be 120-300nm, and more preferably 180nm-250nm.

[0298] The absolute value of the delay in the thickness direction of plate B18 at a wavelength of 550 nm is not particularly limited, but from the viewpoint of better performance of the present invention, it is preferably 200 to 380 nm, and more preferably 240 to 350 nm.

[0299] There are no particular restrictions on the materials constituting plate B18; it can be a layer formed using liquid crystal compounds or a resin film.

[0300] <Uses>

[0301] The image display system of the present invention can be applied to a variety of purposes.

[0302] For example, in-vehicle head-up displays can be cited.

[0303] When the image display system of the present invention is used as an in-vehicle head-up display, it is preferable to use the vehicle's windshield as the screen.

[0304] Example

[0305] The following examples and comparative examples further illustrate the features of the present invention. The materials, amounts, proportions, processing contents, and processing steps shown in the following examples can be appropriately modified without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limited by the specific examples shown below.

[0306] <Example 1>

[0307] The surface of a cellulose acylated membrane (40 μm thick TAC substrate; TG40FUJIFILMCo., Ltd.) serving as a support was saponified with an alkaline solution. The following composition for forming a barrier layer and PVA alignment film was then applied onto the membrane using a wire rod. The support with the coated film was dried with warm air at 60°C for 60 seconds, and then with warm air at 100°C for 120 seconds to form a barrier layer and PVA alignment film, resulting in a transparent support with the barrier layer and PVA alignment film. The thickness of the barrier layer and PVA alignment film was 0.5 μm.

[0308]

[0309] Modified polyvinyl alcohol

[0310] [Chemical Formula 6]

[0311]

[0312] Furthermore, the barrier layer, which also serves as the PVA alignment film, is subjected to a friction treatment. The following composition for forming a tilted liquid crystal alignment film is then coated onto it using a wire rod. The coated film is heated with warm air at 120°C for 30 seconds to form a dried film. Then, a high-pressure mercury lamp is used at an illuminance of 200 mW / cm². 2 A tilted liquid crystal alignment film was fabricated by irradiating the film for 1 second under the specified irradiation conditions. The thickness of the fabricated tilted liquid crystal alignment film was 0.60 μm.

[0313]

[0314] Low molecular weight liquid crystal compound M-1

[0315] [Chemical Formula 7]

[0316]

[0317] Surfactant F-1

[0318] [Chemical Formula 8]

[0319]

[0320] Using a wire rod, the following light-absorbing anisotropic layer forming composition P1 was coated onto the prepared tilted liquid crystal alignment film. The coated film was heated with warm air at 120°C for 30 seconds, and then temporarily cooled to room temperature. Next, it was heated again at 80°C for 60 seconds, and then cooled again to room temperature. Then, an LED lamp (center wavelength 365nm) was used at an illuminance of 200mW / cm². 2 An anisotropic light-absorbing layer P1 was fabricated by irradiating the film under the specified irradiation conditions for 1 second, resulting in an optical thin film 1 comprising the anisotropic light-absorbing layer P1. The thickness of the fabricated anisotropic light-absorbing layer P1 was 2.1 μm.

[0321] Furthermore, relative to the total solid content of the composition P1 for forming anisotropic light-absorbing layers, the content of dichroic substances in the composition P1 for forming anisotropic light-absorbing layers is 21.7% by mass.

[0322]

[0323] Dichroic substance D-1

[0324] [Chemical Formula 9]

[0325]

[0326] Dichroic substance D-2

[0327] [Chemical Formula 10]

[0328]

[0329] Dichroic substance D-3

[0330] [Chemical Formula 11]

[0331]

[0332] P-1, a polymeric liquid crystal compound

[0333] [Chemical Formula 12]

[0334]

[0335] Surfactant F-2

[0336] [Chemical Formula 13]

[0337]

[0338] The above-mentioned composition for forming the barrier layer and PVA alignment film was coated onto the fabricated light-absorbing anisotropic layer P1 using a wire rod and dried at 80°C for 5 minutes. Then, under conditions of 100 ppm oxygen concentration and 60°C, an LED lamp (center wavelength 365 nm) was used at an illuminance of 150 mW / cm². 2 The obtained coated film was irradiated for 2 seconds under the specified irradiation conditions, thereby forming a barrier layer on the light-absorbing anisotropic layer P1. The thickness of the barrier layer was 1.0 μm.

[0339] As an image projection device, the iPad (registered trademark) MD510 / DA (made by Apple Inc.) was used.

[0340] The optical film 1, comprising the light-absorbing anisotropic layer P1 prepared above, is bonded to the iPad (registered trademark) using an optical adhesive. At this time, the direction of the axis on which the transmittance center axis of the light-absorbing anisotropic layer P1 is projected onto the surface of the light-absorbing anisotropic layer P1 is orthogonal to the absorption axis of the polarizer on the visual recognition side of the iPad (registered trademark), and the side of the optical film 1 opposite to the support side faces the iPad (registered trademark).

[0341] Next, as Figure 1 As shown, an image projection system is fabricated by configuring an optical thin film 1, including a light-absorbing anisotropic layer P1, disposed on the surface of the image projection device and a screen 1, which serves as a glass plate. The image projection device is horizontally positioned, and the angle (polar angle) between the normal direction of the surface of the image projection device and the center of the transmission window connecting the image projection device and the center of the projection light illumination area on the screen 1 is 27°. The angle between the line connecting the center of the transmission window of the image projection device and the center of the projection light illumination area on the screen 1 and the central axis of the transmittance of the light-absorbing anisotropic layer P1 is 17°. The central axis of the transmittance of the light-absorbing anisotropic layer P1 is further inclined towards the image projection device than the line connecting the center of the transmission window of the image projection device and the center of the projection light illumination area on the screen 1, and the angle between the normal direction of the surface of the image projection device and the central axis of the transmittance of the light-absorbing anisotropic layer P1 is 44°.

[0342] In addition, the azimuth angle of the line connecting the center of the transmission window of the image projection device and the center of the irradiation area of ​​the projection light on the screen 1 is parallel to the azimuth angle of the central axis of the transmittance of the light absorption anisotropic layer P1.

[0343] And, as Figure 1 As shown, the transmissivity central axis of the light-absorbing anisotropic layer P1 faces the screen side. More specifically, a screen (especially the area illuminated by the projection light) is arranged in the direction extending along the transmissivity central axis of the light-absorbing anisotropic layer P1.

[0344] Furthermore, the position of the observer and the position and angle of screen 1 are adjusted so that the image projected from the center of the image projection device is located at approximately the center of screen 1.

[0345] <Example 2>

[0346] Instead of composition P1 for forming anisotropic light-absorbing layers, composition P2 for forming anisotropic light-absorbing layers was used. Otherwise, an image projection system was fabricated according to the same steps as in Example 1.

[0347] Furthermore, relative to the total solid content of the composition P2 for forming anisotropic light-absorbing layers, the content of dichroic substances in the composition P1 for forming anisotropic light-absorbing layers is 13.0% by mass.

[0348]

[0349] <Example 3>

[0350] The surface of a cellulose acylated membrane (a 40 μm thick TAC substrate; TG40 FUJIFILM Co., Ltd.) was saponified with an alkaline solution, and the above-mentioned barrier layer / PVA alignment film forming composition was coated onto it using a wire rod. The support with the coated film was dried in warm air at 60°C for 60 seconds, and then dried in warm air at 100°C for 120 seconds to form an alignment film, thus obtaining a TAC film with an alignment film. The thickness of the alignment film was 1 μm.

[0351] The following light-absorbing anisotropic layer forming composition P3 is continuously coated onto the obtained alignment film using a wire rod, heated at 120°C for 60 seconds, and then cooled to room temperature (23°C).

[0352] Next, heat at 80°C for 60 seconds, and then cool again to room temperature.

[0353] Then, using an LED light (center wavelength 365nm) at an illuminance of 200mW / cm² 2 The light-absorbing anisotropic layer P3 was fabricated on the alignment film by irradiating it for 2 seconds under the specified irradiation conditions. The thickness of the light-absorbing anisotropic layer P3 was 3.5 μm.

[0354]

[0355] Compound E-1

[0356] [Chemical Formula 14]

[0357]

[0358] Compound E-2

[0359] [Chemical Formula 15]

[0360]

[0361] The following color-adjusting layer composition was continuously coated onto the obtained light-absorbing anisotropic layer P3 using a wire rod to form a coated film.

[0362] Next, the support with the coated film was dried in warm air at 60°C for 60 seconds, and then dried in warm air at 100°C for 120 seconds to form the tone adjustment layer C1, thus obtaining an optical film 3 comprising the light absorption anisotropic layer P3 and the tone adjustment layer C1. The thickness of the tone adjustment layer is 0.5 μm.

[0363]

[0364] Pigment compound G-1

[0365] [Chemical Formula 16]

[0366]

[0367] Next, optical film 3 is used instead of optical film 1, and optical film 3 is attached to the image projection device following the same steps as in Example 1. Furthermore, the transmittance central axis of the light-absorbing anisotropic layer P3 is parallel to the normal direction of the surface of the light-absorbing anisotropic layer P3.

[0368] Next, as Figure 6 As shown, an image projection system is fabricated by configuring an optical thin film 3, including a light-absorbing anisotropic layer P3, disposed on the surface of the image projection device and a screen 1. The image projection device is horizontally positioned, and the angle (polar angle) between the normal direction of the surface of the image projection device and the center of the projection light illumination area on the screen 1 (connecting the center of the transmission window of the image projection device and the center of the projection light illumination area on the screen 1) is 0°. The line connecting the center of the transmission window of the image projection device and the center of the projection light illumination area on the screen 1 is parallel to the central axis of the transmittance of the light-absorbing anisotropic layer P1.

[0369] And, as Figure 6 As shown, the transmissivity central axis of the light-absorbing anisotropic layer P1 faces the screen side. More specifically, a screen (especially the area illuminated by the projection light) is arranged in the direction extending along the transmissivity central axis of the light-absorbing anisotropic layer P1.

[0370] Furthermore, the position of the observer and the position and angle of screen 1 are adjusted so that the image projected from the center of the image projection device is located at approximately the center of screen 1.

[0371] <Example 4>

[0372] The thickness of the tilted liquid crystal alignment film in Example 1 was changed from 0.60 μm to 1.0 μm. Otherwise, an image projection system was fabricated according to the same steps as in Example 1.

[0373] In addition, in Embodiment 4, the angle (polar angle) between the line connecting the center of the transmission window of the image projection device and the center of the projection light illumination area on screen 1 is 28°. The angle between the line connecting the center of the transmission window of the image projection device and the center of the projection light illumination area on screen 1 and the transmissivity central axis of the light absorption anisotropic layer P1 is 11°. The transmissivity central axis of the light absorption anisotropic layer P1 is further inclined towards the image projection device than the line connecting the center of the transmission window of the image projection device and the center of the projection light illumination area on screen 1, and the angle between the normal direction of the surface of the image projection device and the transmissivity central axis of the light absorption anisotropic layer P1 is 39°.

[0374] In addition, the azimuth angle of the line connecting the center of the transmission window of the image projection device and the center of the irradiation area of ​​the projection light on the screen 1 is parallel to the azimuth angle of the central axis of the transmittance of the light absorption anisotropic layer P1.

[0375] Furthermore, the transmissivity central axis of the light-absorbing anisotropic layer P1 faces the screen side. More specifically, a screen (especially the area illuminated by the projection light) is arranged in the direction extending from the transmissivity central axis of the light-absorbing anisotropic layer P1.

[0376] <Example 5>

[0377] According to the steps described in paragraphs 0101 to 0129 of WO2016 / 052367, an optical functional layer HM-1 was fabricated, which sequentially includes a λ / 2 phase retardation layer, a cholesterol-type liquid crystal layer 1, a cholesterol-type liquid crystal layer 2, and a cholesterol-type liquid crystal layer 3.

[0378] Furthermore, the selective reflection center wavelength of cholesterol-type liquid crystal layer 1 is 540 nm, that of cholesterol-type liquid crystal layer 2 is 641 nm, and that of cholesterol-type liquid crystal layer 3 is 761 nm. Additionally, the in-plane retardation of the λ / 2 phase retardation layer at a wavelength of 550 nm is 276 nm.

[0379] Using the obtained optical functional layer HM-1, a screen 2 was fabricated by sandwiching the aforementioned optical functional layer HM-1 between two glass plates, according to the steps described in paragraph 0130 of WO2016 / 052367.

[0380] Except that screen 2 was used instead of screen 1, the image projection system was made according to the same steps as in embodiment 4.

[0381] <Example 6>

[0382] A screen 3 comprising a multilayer reflective film was fabricated according to the steps of Example 1 in Japanese Patent Application Publication No. 2013-054350. The multilayer reflective film has a structure consisting of two layers with different refractive indices stacked repeatedly.

[0383] Except that screen 3 was used instead of screen 1, the image projection system was made according to the same steps as in embodiment 4.

[0384] <Example 7>

[0385] like Figure 8 As shown, in the image projection system, a B plate made of cyclic olefin resin is disposed between the image projection device and the optical film including the light-absorbing anisotropic layer. Otherwise, the image projection system is fabricated according to the same steps as in Example 5.

[0386] The in-plane retardation of the aforementioned plate B at a wavelength of 550nm is 227nm, and the thickness-direction retardation at a wavelength of 550nm is 285nm.

[0387] <Comparative Example 1>

[0388] Except that optical film 1 was not used, the image projection system was fabricated according to the same steps as in Example 1.

[0389] <Evaluation>

[0390] In the image projection device of the aforementioned image projection system, an evaluation image is illuminated, and the ease of visual recognition of the image displayed on the screen in the dark room is evaluated. At the same time, the brightness (nW) near the screen is also evaluated.

[0391] In addition, in the image projection system, the distance between the image projection device and the observer is approximately 650 mm, and the distance between the image projection device and the screen is approximately 350 mm.

[0392] The brightness near the screen in the darkroom was measured at a wavelength of 520 nm using a power meter (VEGA, OPHIR).

[0393] The evaluation used images to display strings of letters in RGB colors on the screen, and the ease of viewing was sensorily assessed according to the following criteria. The text size was adjusted to approximately 3cm on the screen.

[0394] Five observers were randomly selected, and each person provided an evaluation based on the following ratings. The average of these ratings was used as the final visual recognition ease score, which is shown in Table 1 as "Visual Recognition Ease of Images on the Screen". In addition, the observers allowed their eyes to acclimatize for approximately 30 minutes in a dark room before beginning the actual evaluation.

[0395] One point is difficult to visually identify.

[0396] 2 points are difficult to visually identify

[0397] 3 points generally

[0398] 4 points that are easy to visually identify

[0399] The 5 points are easy to visually identify.

[0400] In Table 1, "Angle X" represents the angle (°) between the central axis of the transmittance of the light-absorbing anisotropic layer and the normal direction of the light-absorbing anisotropic layer.

[0401] "Angle Y" represents the angle (°) between the line connecting the center of the transmission window of the image projection device and the center of the area illuminated by the projected light on the screen, and the central axis of the transmittance of the light-absorbing anisotropic layer.

[0402] "Content of dichroic substances (mass%)" indicates the content (mass%) of dichroic substances relative to the total mass of the light-absorbing anisotropic layer.

[0403] [Table 1]

[0404]

[0405] As shown in Table 1, the image projection system of the present invention represents the desired effect.

[0406] Furthermore, a comparison between Example 1 and Example 2 confirmed that when the content of dichroic material is 15% by mass or more relative to the total mass of the light absorption anisotropic layer, the effect is even better.

[0407] Furthermore, a comparison between Example 1 and Example 4 confirms that the effect is better when the angle Y is within 15°.

[0408] As shown in Examples 5 and 6, it was confirmed that the effect was even better when the screen had a reflective layer.

[0409] As shown in Example 7, it was confirmed that the effect was better when using board B.

[0410] Symbol Explanation

[0411] 10A, 10B, 10C, 10D - Image projection system; 12 - Image projection device; 14A, 14B - Screen; 16A, 16B - Light absorption anisotropic layer; 18 - Plate B; 20 - Transmission window; 22 - Irradiation area; 30 - Support; 32 - Reflective layer.

Claims

1. An image projection system, comprising: An image projection device that emits projection light as linearly polarized light; The screen is illuminated by projection light emitted from the image projection device; and An anisotropic light-absorbing layer is disposed between the image projection device and the screen to allow the projected light to pass through. The light-absorbing anisotropic layer contains a dichroic material. The transmissivity central axis of the light-absorbing anisotropic layer is oriented toward the screen.

2. The image projection system according to claim 1, wherein, The projection area on the screen is located in the direction extending from the central axis of the light-absorbing anisotropic layer.

3. The image projection system according to claim 1, wherein, The angle between the line connecting the center of the transmission window of the image projection device and the center of the irradiation area of ​​the projection light on the screen and the transmissivity central axis of the light absorption anisotropic layer is 0 to 30°.

4. The image projection system according to claim 1, wherein, The light-absorbing anisotropic layer contains dichroic material. The content of the dichroic substance is 10.0% by mass or more relative to the total mass of the light-absorbing anisotropic layer.

5. The image projection system according to claim 1, wherein, The screen includes a reflective layer that reflects the projected light.

6. The image projection system according to claim 5, wherein, The reflective layer is a cholesterol-type liquid crystal layer or a multilayer reflective film.

7. The image projection system according to claim 1, wherein, It also has a B board. The B plate is disposed between the image projection device and the light absorption anisotropic layer, allowing the projected light to pass through.

8. The image projection system according to any one of claims 1 to 7, wherein, The image projection system is used as a vehicle-mounted head-up display.

9. The image projection system according to claim 8, wherein, The vehicle's windshield is used as the screen.

Images