JP7411361B2 - Polarized light source and display device that suppresses light reflection - Google Patents

Description

The present invention converts light emitted from a light-inducing source into polarized light, or utilizes light emitted from a light-inducing source to emit polarized light, and irradiates the light onto a reflective medium. The present invention relates to a light source or a display device that can provide polarized light in the visible range such that polarized light is incident in a direction perpendicular to the light source.

Generally, the human eye and a camera, which is an image recognition device, detect light as an image of the surroundings. In recent years, image recognition devices have become indispensable in autonomous driving safety technology in the automobile field, robot field, etc., and automatic safety devices are normally activated by sensing changes in light due to motion using a camera. This automatic safety device senses not only light in the visible range, but also various types of light, including light in the ultraviolet and infrared ranges. Therefore, it is necessary to eliminate malfunctions in light sensing, and various related technologies are disclosed, for example, in Patent Documents 1 and 2. One of the main causes of malfunctions is due to reflected light. For example, if there is a puddle, snow surface, or ice surface on the road, they will function as a light reflecting surface, and if light indicating the presence of people or traffic lights is reflected on these surfaces, the There is a risk that the safety device may mistakenly recognize that there are people or traffic lights in the area. This misrecognition not only causes self-driving cars, motorcycles, and robots to malfunction, but it can also cause misrecognition to the human eye.

Such misrecognition can occur not only in outdoor environments but also in indoor environments, especially light reflection from water areas, marble, ceramics, stainless steel furniture, etc. In recent years, the use of devices that utilize face recognition and motion recognition functions has been increasing even indoors, so there has been a need for technology that prevents malfunctions due to erroneous recognition.

Patent No. 5859897 Japanese Patent Application Publication No. 2014-072592

Conventional autonomous driving safety devices and cameras take measures to prevent malfunctions through image processing on the side that receives light. However, it has been difficult to determine whether the received light is reflected light or not. The conventional method for preventing malfunctions has been to use a camera or application on the light receiving side to suppress reflections, but the fundamental method is to take measures to prevent reflection of the light itself on the emitting side. It wasn't. In contrast, the invention of the present application provides a prescription for preventing misrecognition caused by conventional light irradiating the surrounding environment, and not only eliminates the malfunction of automatic safety devices, but also improves visibility for humans. The object of the present invention is to provide a light source and a display device that can improve the image quality.

As a result of intensive research to achieve this objective, the inventors of the present invention converted the light emitted from the light-inducing source into polarized light, or emitted polarized light using the light emitted from the light-inducing source. To provide a light source or a display device that emits polarized light in the visible light range so that vertically polarized light is incident on the reflective medium when the light is irradiated onto the reflective medium. They discovered that it is possible to prevent erroneous recognition by the human eye and erroneous recognition by safety devices that recognize light and motion, and have completed the present invention. Furthermore, it has been found that by using the technology of the present invention, it is possible to realize a display device in which the light source is transparent and can also display characters and images. Particularly, the present invention is important in that it can prevent malfunctions due to misrecognition of various devices in an environment where light reflection may occur due to a light-reflecting medium.

That is, the present invention relates to 1) to 8).
1)
When converting the light emitted from a light-inducing source into polarized light, or emitting polarized light using the light emitted from a light-inducing source, and irradiating the light onto a medium that reflects the light, it is perpendicular to the reflecting medium. A light source or display device capable of providing polarized light in the visible range such that polarized light in a direction is incident thereon.
2)
The light source or display device according to item 1), wherein the light transmittance is 40% or more and 100% or less.
3)
The light source or display device 4) according to 1) or 2), which includes a polarized light emitting element that emits polarized light in the visible range.
The light source according to item 3), wherein the polarized light emitting element is a polarized light emitting element that emits light in the visible range using light in the ultraviolet to near ultraviolet visible range emitted from a light-inducing source; or display device.
5)
An optical system comprising the light source or display device according to any one of 1) to 4) above, further comprising a medium capable of reflecting light.
6)
The light source or display device according to any one of 1) to 4), or the optical system according to 5), which is used outdoors.
7)
The light source or display device according to any one of 1) to 4), or the optical system according to 5), which is used for a driving device.
8)
The light source or display device according to any one of 1) to 4), or the optical system according to 5), which is used for vehicles such as automobiles, motorcycles, and bicycles, or ships.

When converting the light emitted from a light-inducing source into polarized light, or emitting polarized light using the light emitted from a light-inducing source, and irradiating the light onto a medium that reflects the light, it is perpendicular to the reflecting medium. By providing a light source or a display device that can provide polarized light in the visible range so that polarized light in the direction is incident, it is possible to prevent erroneous recognition by the human eye or by safety equipment that recognizes light and motion. Malfunctions, etc. can be prevented. In particular, the present invention is important in that it can prevent misrecognition by various devices in an environment where light reflection may occur due to a light-reflecting medium. Further, according to the technology of the present invention, it is possible to provide a light source that emits visible polarized light while having a transmittance of 90% or more, resulting in a light source that is transparent but can emit polarized light. Furthermore, since the light source emits polarized light in the visible range even when light in the ultraviolet range is incident thereon, it is possible to provide the light source or display device of the present invention using invisible light as a light inducing source. Furthermore, it is possible to provide a display device that can provide any image by controlling the polarization of the liquid crystal cell.

It is preferable that the light source or display device emits vertically polarized light even when a polarized light-shielding plate is used on the light-receiving side or a driver of an automobile or two-wheeled vehicle uses polarized lenses or polarized sunglasses. Generally, absorption type polarized lenses and polarized sunglasses are used for safety devices such as automobiles and drivers, but the light absorption axis of the light absorption type polarized lenses and polarized sunglasses is horizontal to the reflective medium, that is, The direction is parallel. The reason for this is that since the light reflected from water surfaces, snow, asphalt, etc. is in the horizontal direction (S-polarized light), only that polarized light is absorbed, and the light of the opposite axis, that is, the direction perpendicular to the reflecting medium ( This is because the purpose of transmitting P-polarized light is to obtain information that suppresses reflections from the surrounding environment, improve visibility, prevent misidentification, and reduce malfunctions due to eye fatigue or misidentification of equipment. . If the light source or display device of the present invention is provided, it can provide only vertically polarized light to the surroundings, so it can not only provide the above-mentioned anti-reflection effect, but also be able to be used with general polarized lenses or polarized sunglasses. Information can be provided to the driver and equipment without interfering with the display. Therefore, the light source and display device of the present invention are preferable because they can provide accurate visual information even to devices and drivers using general polarized lenses or polarized sunglasses.

Photograph substituted for drawing of Example 3

Photograph substituted for drawing of Comparative Example 3

When converting the light emitted from a light-inducing source into polarized light, or emitting polarized light using the light emitted from a light-inducing source, and irradiating the light onto a medium that reflects the light, it is perpendicular to the reflecting medium. The present invention is characterized in that it is a light source or a display device that can provide polarized light in the visible range such that polarized light in a certain direction is incident thereon. Note that the horizontal direction or vertical direction in the present application does not refer to an extremely accurate angle, for example, 0° or 90°, but only roughly represents the direction. Specifically, when the vertical direction is 0° and the horizontal direction is 90°, the effect of the present application can be achieved even if the angle differs by about ±10° with respect to each direction.

It is generally known that light will be reflected if there is a medium that reflects light, and that the reflected light has polarization. For example, if the incident light makes an angle between 30° and 80° with the medium that reflects the light, the reflected and visible light will have a relatively strong polarization. In general, when the angle corresponds to the "Brewster angle", light that is perpendicular to the reflective medium is reflected significantly less, and the ratio of light that is polarized horizontally to the reflective medium is reflected. becomes larger. In other words, reflected light has polarization, and the present application provides a light source or display device that utilizes this phenomenon, and provides a light source or display device that can emit polarized light so that the light is incident perpendicularly to the medium that reflects the light. By doing so, it is possible to provide a light source that can suppress reflection of light and a display device using the same.

The angle between the light source or the display device of the present application and the medium that reflects light is not particularly limited, and the light source or the display device may be arranged at any angle. The angle formed between the light emitted (emitted) from the light source or display device and the medium that reflects the light is between 30° and 85°, assuming that the direction perpendicular to the reflecting medium is 0°. The angle is preferably 40° to 80°, more preferably 50° to 75°. It should be noted that the total amount of light emitted from the light source or display device of the present application does not necessarily have to be within the range of 30° to 85°, and some of the light incident on the reflective medium may be emitted within this angle range to prevent reflection. A light source or display device that can be reduced or suppressed can be achieved.

The above-mentioned medium that reflects light includes, for example, those that exist in the natural environment such as water, snow, ice, stones, and leaves, as well as metals such as silver, aluminum, copper, and iron, mirrors, plastics, marble, asphalt, Examples include paper and glass, as well as asphalt and plastic to which water, snow, ice, etc. have adhered, and the medium is not particularly limited as long as it can reflect light.

In order to realize the light source or display device used in the present invention, it is necessary to have a light-inducing source to make it emit light, and to convert the light from the light-inducing source into polarized light, or to convert the light from the light-inducing source into polarized light. It is necessary to use polarized light to emit light. The light source used in this application or the light inducing source that can enter the display device is not particularly limited as long as it can emit light, and examples include an LED lamp, a white light bulb, a xenon lamp, and an ultraviolet lamp. , a mercury lamp, etc. can be used, and there is no particular limitation. The light-inducing source used in the present invention may be a general light-emitting device as long as it can emit light. As general light-emitting devices, devices that can emit light and display images, such as liquid crystal displays, OLEDs, FEDs, CRTs, LED displays, and LED microdisplays, can be used. The wavelength of the light from these light-inducing sources is not limited and may be any wavelength. For example, a light-inducing source capable of emitting light with wavelengths in the ultraviolet, visible, and infrared regions can be used.

The polarization axis of the polarized light emitted from the light source or display device of the present application needs to be vertically polarized light when the medium that reflects the light is in the horizontal direction. Vertical polarization is also commonly referred to as "P-polarization." By irradiating a medium that reflects light with vertically polarized light, the reflected light is attenuated and light reflection can be suppressed. In the present invention, in order to provide a light source or a display device that emits "P-polarized light" which is polarized light in the visible range so that light polarized in the vertical direction is incident on a medium that reflects light, it is necessary to To convert the light from the triggering source into polarized light, place an optical element that can convert the light into polarized light, such as a general polarizing plate, on the outermost surface of the light triggering source, or use the light emitted from the light triggering source. The embodiment of the technology of the present application can be achieved by using an element capable of emitting polarized light (polarized light emitting element) to emit light polarized perpendicularly to a reflecting medium.

(Polarizer)
The polarizing plate is not particularly limited as long as it has the function of converting light from a light-inducing source into polarized light. Preferably, it has a function of converting visible light into polarized light. Examples of the polarizing plate include an iodine-based polarizing plate, a dye-based polarizing plate, a dye-based polarizing plate that can control polarization only at a specific wavelength, a type of polarizing plate using polyene, a wire grid type polarizing plate, etc. Also good. The polarizing plate has polarization performance for light in a part or all of the wavelength range of 400 to 700 nm. Examples of iodine-based polarizing plates include those described in JP-A-2001-290029 and JP-A-2010-072548, and examples of dye-based polarizing plates include JP-A 2001-033627 and JP-A 2004-251962. For dye-based polarizing plates that can polarize only specific wavelengths, examples include those described in JP-A No. 2007-084803, JP-A No. 2007-238888, etc. Polarizing plates using polyene include those described in Japanese Translated Patent Publication No. 2005-527847, Japanese Translated Patent Publication No. 2005-517974, etc., and wire grid type polarizing plates include those described in Japanese Translated Patent Publication No. 2003-519818. , those described in Japanese Patent Application Publication No. 2003-502708 and the like. As reflective polarizing plates, US Pat. Examples include those described in WO2011/074701 and the like, and an example of the product is DBEF (manufactured by 3M). Further, it is preferable to use a reflective polarizing plate as the polarizing plate because it not only allows uniaxial linearly polarized light to pass through but also allows light polarized with a different axis to be reflected internally and reused. Therefore, one preferable embodiment of the present invention is to use the above reflective polarizing plate as the polarizing plate. Further, the light source or display device of the present invention can be achieved by arranging each of the above polarizing plates in the light inducing source so that the light incident on the reflective medium becomes vertically polarized light (P-polarized light). It is mentioned as one preferable form because it absorbs water.

In the above, one preferable form for achieving the function of the present application is to arrange the polarizing plate so that the axis of polarization is perpendicular to the reflective medium, that is, P-polarized light is emitted to the reflective medium. However, as a polarizing plate whose axis of polarization is perpendicular to the reflecting medium, that is, which can provide P-polarized light to the reflecting medium, the absorption axis of an iodine-based polarizing plate or a dye-based polarizing plate is perpendicular to the reflecting medium. This can be achieved by arranging the absorption axis of the polarizing plate in a direction parallel to the reflection medium, that is, in a direction parallel to the reflection medium. By arranging the absorption axis of the iodine-based polarizing plate or the dye-based polarizing plate in the horizontal direction, only vertically polarized light is transmitted, and reflection of vertically oriented light is suppressed, so that the light source or display of the present application equipment may be provided.

More preferably, in order to improve visibility, it is preferable to use an element that emits polarized light in the visible light region during display, instead of using an absorption type or birefringence type polarizing plate. In this application, an element that emits polarized light in the visible light range may be abbreviated as a "polarized light emitting element."

The above-mentioned polarized light emitting element refers to an element that emits polarized light in the visible range by irradiating the element with light in the ultraviolet to visible range from a light-inducing source, and utilizes the light emitting function of the element to act as a light source. It can also be used as a display device. The direction of the polarized light emitted from the element is perpendicular to the reflective medium, specifically a wave (P-polarized light) perpendicular to the reflective medium, so that it can be used as a light source or for display using it. equipment can be obtained.

It is more preferable that the polarized light emitting element has a high light transmittance because it is possible to obtain not only a display of polarized light emitted but also information transmitted through the element. Display devices that have the characteristics of achieving both transparency and display are called transparent displays or see-through displays, and in addition to the displayed information, the background can also be viewed through the display. For example, by placing a sign, signboard, or general display device behind a light source or display device that emits light in a direction perpendicular to the reflective medium (P-polarized light) of the present invention, the information can be provided to people and equipment. However, it is possible to provide light with reduced reflection from a light source or display device.

Although it is preferable that the polarized light emitting element has high optical transparency, the transparency is not limited. Generally, having a transmittance of 40% to 100% makes it easy to see the background through the medium, so for example, the light source or display device has a light transmittance of 40% to 100%. For example, if it is 50% or more, it functions well as a device that provides background information, preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, particularly preferably 85% or more is good.

As a method for maintaining the transparency of the polarized light emitting element, it is preferable that the element emits polarized light in the visible range, but absorbs all or only part of the light in the visible range of 380 to 780 nm. For example, It is preferable to obtain a polarized light-emitting element that emits polarized light in the visible region using light in the ultraviolet to near-ultraviolet-visible region. Furthermore, emitting light in the visible range using light in the ultraviolet to near-ultraviolet visible range from a light-inducing source is generally called fluorescence emission or phosphorescence emission, and in this application, the emitted light is polarized. Fluorescence is preferred.

One preferred form of an element (polarized light emitting element) that emits visible light using light in the ultraviolet to near-ultraviolet-visible range is, for example, in the light wavelength region, light with a wavelength shorter than 430 nm, emitting light in the ultraviolet to near ultraviolet visible range. It is an element that absorbs light in the near-ultraviolet-visible range and emits polarized light having an emission spectrum peak in part or all of the visible range from 380 nm to 780 nm, and includes the substrate described below and one or more polarized light-emitting dyes. Contains at least The light in the ultraviolet to near-ultraviolet visible range that is irradiated to cause the polarized light emitting element to emit polarized light is preferably light in the range of 300 to 430 nm, but it is invisible to the naked eye or has a wavelength to which the eye is extremely sensitive. It is preferable to use light of Therefore, it is preferable to use light with a wavelength of 340 to 415 nm, further preferably 350 to 400 nm, particularly preferably 350 to 390 nm. The irradiated light in the ultraviolet to near ultraviolet visible range may or may not be polarized, and may have polarized light. The light in the ultraviolet to near ultraviolet visible range that is irradiated to such a polarized light emitting element may be a general light-inducing source such as an LED, or may be natural light including light in the ultraviolet to near ultraviolet visible range, such as sunlight.

<Base material>
The polarized light emitting element uses a polymer film as a base material for adsorbing and orienting a polarized light emitting dye, which will be described later. The polymer film is preferably a hydrophilic polymer film obtained by forming a hydrophilic polymer capable of adsorbing general dichroic polarized light-emitting dyes, particularly dyes having a stilbene skeleton or dyes having a biphenyl skeleton. Polymer film is good. The hydrophilic polymer is not particularly limited, but for example, polyvinyl alcohol-based resins and starch-based resins are preferable. Preferably, they are resins and derivatives thereof. Examples of the above-mentioned polyvinyl alcohol-based resins and derivatives thereof include polyvinyl alcohol or derivatives thereof, and combinations of any of these with olefins such as ethylene and propylene, and monomers such as crotonic acid, acrylic acid, methacrylic acid, and maleic acid. Examples include those modified with saturated carboxylic acids and the like. Among these, a film made of polyvinyl alcohol or a derivative thereof is preferably used from the viewpoint of adsorption and orientation of polarized light-emitting dyes having dichroism. The base material may be, for example, a film made of a commercially available polyvinyl alcohol resin or a derivative thereof, or may be produced by forming a polyvinyl alcohol resin into a film. The method for forming a polyvinyl alcohol resin film is not particularly limited. Known film-forming methods can be employed, such as gelling, extraction and removal of the solvent), cast film-forming method (pouring an aqueous polyvinyl alcohol solution onto a substrate and drying), and a combination thereof. The thickness of the base material is usually about 10 to 100 μm, preferably about 20 to 80 μm.

<Method for manufacturing polarized light emitting element>
Although the method for manufacturing the polarized light emitting device is not limited to the following manufacturing method, it is preferable to use a film mainly made of polyvinyl alcohol or a derivative thereof. A method for producing a polarized light emitting device using a film made of polyvinyl alcohol or its derivatives will be described.

The method for producing the polarized light-emitting device includes a step of preparing a base material, a swelling step of immersing the base material in a swelling liquid to swell the base material, and a step of immersing the base material in a swelling liquid to swell the base material, and adding one or more of the polarized light-emitting dyes to the swollen base material. A dyeing process in which the substrate is impregnated with a dyeing solution containing at least a polarized light emitting dye and the polarized light emitting dye is adsorbed onto the base material. A crosslinking step in which the polarized light-emitting dye is cross-linked is uniaxially stretched in a certain direction to align the polarized light-emitting dye in a certain direction.If necessary, the stretched substrate is washed with a cleaning solution. A manufacturing method including a washing step of washing and/or a drying step of drying the washed substrate will be described below by way of example.

(swelling process)
The above swelling step will be explained. The swelling step is preferably carried out by immersing the base material in a swelling liquid at 20 to 50°C for 30 seconds to 10 minutes, and the swelling liquid is preferably water. The stretching ratio of the base material by the swelling liquid is preferably adjusted to 1.00 to 1.50 times, more preferably 1.10 to 1.35 times.

(dying process)
The above dyeing process will be explained. One or more types of polarized light-emitting dyes described below are adsorbed onto the base material obtained through the above swelling step. The dyeing process is not particularly limited as long as it is a method that can adsorb the polarized light-emitting dye to the base material, but examples include a method in which the base material is immersed in a dyeing solution containing the polarized light-emitting dye, or a method in which the base material Examples include a method of applying a dyeing solution containing a polarized light-emitting dye, but a method of immersing it in a dyeing solution containing a polarized light-emitting dye is preferred. The concentration of the polarized light-emitting dye in the dyeing solution is not particularly limited as long as the polarized light-emitting dye is sufficiently adsorbed in the base material, but for example, it is 0.0001 to 1% by mass in the dyeing solution. It is preferably 0.0001 to 0.5% by mass, and more preferably 0.0001 to 0.5% by mass. The temperature of the dyeing solution in the dyeing step is preferably 5 to 80°C, more preferably 20 to 50°C, particularly preferably 40 to 50°C. Further, the time for immersing the substrate in the dyeing solution can be adjusted as appropriate, and is preferably adjusted between 30 seconds and 20 minutes, and more preferably between 1 and 10 minutes. The polarized light-emitting dyes contained in the dyeing solution may be used alone or in combination of two or more. Since the polarized light-emitting dyes emit different colors due to differences in dye structure, etc., the emitted light colors produced can be appropriately adjusted to various colors by containing multiple types of the above-mentioned polarized light-emitting dyes in the base material. Can be done. Moreover, if necessary, the dyeing solution may further contain one or more organic dyes and/or fluorescent dyes.

(polarized light-emitting dye)
The polarized light-emitting dye is a compound or a salt thereof that has at least one of a stilbene skeleton or a biphenyl skeleton in its structure and emits fluorescence. The polarized light-emitting dye can emit polarized light by having a dichroic ratio while emitting fluorescent light. In particular, polarized light-emitting dyes having a stilbene skeleton or a biphenyl skeleton have excellent fluorescence emission characteristics and, when oriented, have a high dichroic ratio. These properties are derived from each of the above-mentioned skeletons, and in order to further improve these properties or adjust various properties such as absorption wavelength, emission wavelength, light resistance, moisture resistance, ozone gas resistance, etc., and solubility, each of the above-mentioned It is possible to further introduce arbitrary substituents into the skeleton. When introducing this substituent, depending on the type and position of the substituent, it is possible to achieve a high degree of polarization like a conventional dye-based polarizing plate, but the amount of emitted light is significantly reduced. In order to have a high dichroic ratio, it is important to select the type of substituent and the substitution position. Moreover, the above-mentioned polarized light-emitting dyes may be used alone or in combination of two or more.

(a) Dye having a stilbene skeleton The dye having a stilbene skeleton is preferably a compound represented by formula (1) or a salt thereof.

In the above formula (1), L and M each independently include a nitro group, an amino group which may have a substituent, a carbonylamide group which may have a substituent, and a substituent. naphthotriazole group, alkyl group having 1 to 20 carbon atoms which may have a substituent, vinyl group which may have a substituent, amide group which may have a substituent, It represents a good ureido group, an aryl group which may have a substituent, and a carbonyl group which may have a substituent, but is not necessarily limited to these. It is known that the dye having a stilbene skeleton represented by formula (1) emits fluorescence and can obtain dichroism by orientation, but this is mainly due to the stilbene skeleton. and further arbitrary substituents may be introduced. However, when the stilbene skeleton has an azo group at the L position and the M position, the fluorescence emission becomes significantly small, which is not suitable.

Examples of the amino group that may have a substituent include an unsubstituted amino group, methylamino group, ethylamino group, n-butylamino group, tert-butylamino group, n-hexylamino group, dodecylamino group, Alkylamino group having 1 to 20 carbon atoms which may have a substituent such as dimethylamino group, diethylamino group, di-n-butylamino group, ethylmethylamino group, ethylhexylamino group, phenylamino group, diphenyl Substitution of arylamino groups that may have substituents such as amino groups, naphthylamino groups, N-phenyl-N-naphthylamino groups, methylcarbonylamino groups, ethylcarbonylamino groups, n-butyl-carbonylamino groups, etc. Alkylcarbonylamino group having 1 to 20 carbon atoms which may have a group, phenylcarbonylamino group, biphenylcarbonylamino group, arylcarbonylamino group which may have a substituent such as naphthylcarbonylamino group, methylsulfonylamino group group, an alkylsulfonylamino group having 1 to 20 carbon atoms such as an ethylsulfonylamino group, a propylsulfonylamino group, an n-butyl-sulfonylamino group, a phenylsulfonylamino group, a naphthylsulfonylamino group, etc. Good arylsulfonylamino, etc. include an alkylcarbonylamino group having 1 to 20 carbon atoms which may have a substituent, an arylcarbonylamino group which may have a substituent, and an alkylsulfonylamino group having 1 to 20 carbon atoms. An arylsulfonylamino group which may have a group or a substituent is preferable. In addition, an alkylamino group having 1 to 20 carbon atoms which may have the above substituents, an arylamino group having 1 to 20 carbon atoms which may have a substituent, and an alkylcarbonylamino group having 1 to 20 carbon atoms which may have a substituent. There are no particular restrictions on the substituents in the group, the arylcarbonylamino group that may have a substituent, the alkylsulfonylamino group having 1 to 20 carbon atoms, and the arylsulfonylamino group that may have a substituent, but Examples include a nitro group, a cyano group, a hydroxyl group, a sulfonic acid group, a phosphoric acid group, a carboxy group, a carboxyalkyl group, a halogen atom, an alkoxyl group, an aryloxy group, and the like.

Examples of the carboxyalkyl group include a methylcarboxy group and an ethylcarboxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. Examples of the alkoxyl group include a methoxy group, an ethoxy group, and a propoxy group. Examples of the aryloxy group include a phenoxy group and a naphthoxy group.

Examples of the carbonylamide group which may have a substituent include N-methyl-carbonylamide group (-CONHCH ₃ ), N-ethyl-carbonylamide group (-CONHC ₂ H ₅ ), N-phenyl-carbonyl Examples include amide group (-CONHC ₆ H ₅ ).

Examples of the naphthotriazole group which may have the above-mentioned substituent include a benzotriazole group and a naphthotriazole group.

Examples of the alkyl group having 1 to 20 carbon atoms which may have a substituent include a methyl group, ethyl group, n-butyl group, n-hexyl group, n-octyl group, n-dodecyl group, etc. Examples include branched alkyl groups such as chain alkyl groups, isopropyl groups, sec-butyl groups, and tert-butyl groups, and cyclic alkyl groups such as cyclohexyl groups and cyclopentyl groups.

Examples of the vinyl group which may have a substituent include a vinyl group, a methylvinyl group, an ethylvinyl group, a divinyl group, and a pentadiene group.

Examples of the amide group which may have a substituent include an acetamido group (-NHCOCH ₃ ), a benzamide group (-NHCOC ₆ H ₅ ), and the like.

Examples of the above-mentioned aryl group which may have a substituent include a phenyl group, a naphthyl group, a ditracenyl group, a biphenyl group, and the like.

Examples of the carbonyl group which may have a substituent include a methylcarbonyl group, an ethylcarbonyl group, an n-butylcarbonyl group, and a phenylcarbonyl group.

A carbonylamide group which may have the above substituents, a naphthotriazole group which may have a substituent, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and a substituent which may have a substituent. As a substituent in a vinyl group, an amide group which may have a substituent, a ureido group which may have a substituent, an aryl group which may have a substituent, a carbonyl group which may have a substituent is not particularly limited, but may be the same as the substituent described in the section of the amino group which may have a substituent.

The dye having a stilbene skeleton represented by the above formula (1) is particularly preferably a dye represented by the following formula (2) or a salt thereof, or a dye represented by the following formula (3) or a salt thereof. By using these dyes, it is possible to obtain a polarized light-emitting element that emits clearer white light, which is preferable.

In the above formula (2), the substituent R is a halogen atom such as a hydrogen atom, a chlorine atom, a bromine atom, or a fluorine atom, a hydroxyl group, a carboxy group, a nitro group, an alkyl group that may have a substituent, or a substituent. Represents an alkoxyl group that may have a substituent or an amino group that may have a substituent. The alkyl group which may have a substituent may be the same as those mentioned above in the section of the alkyl group having 1 to 20 carbon atoms which may have a substituent. The alkoxyl group which may have a substituent is preferably a methoxy group or an ethoxy group. The amino group which may have a substituent may be the same as mentioned above, and is preferably a methylamino group, dimethylamino group, ethylamino group, diethylamino group, or phenylamino group. The substituent R may be bonded to any carbon of the naphthalene ring in the naphthotriazole ring, but preferably, when the carbons condensed with the triazole ring are the 1st and 2nd positions, the substituent R is bonded to the 3rd and 5th positions. or the 8th position.

In the above formula (2), n is an integer of 0 to 3, preferably 1 to 2. In the above formula (2), the -(SO ₃ H) group may be bonded to any carbon of the naphthalene ring in the naphthotriazole ring. The substitution position of the -(SO ₃ H) group in the naphthalene ring is the 4th, 6th, or 7th position when n = 1 and the carbon condensed with the triazole ring is the 1st and 2nd positions. When n = 2, preferably the 5th and 7th and 6th and 8th positions, and when n = 3, the combination of the 3rd, 6th and 8th positions. is preferred. Further, it is particularly preferable that R is a hydrogen atom and n is 1.

X in the above formula (2) represents a nitro group or an amino group which may have a substituent, and is preferably a nitro group. The amino which may have a substituent may be the same as above, and may include an alkylcarbonylamino group having 1 to 20 carbon atoms which may have a substituent, an arylcarbonylamino group which may have a substituent, Preferably, it is an alkylsulfonylamino group having 1 to 20 carbon atoms or an arylsulfonylamino group which may have a substituent.

Y in the above formula (3) represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, a vinyl group which may have a substituent, or an aryl group which may have a substituent. , preferably an aryl group that may have a substituent, more preferably a naphthyl group that may have a substituent, and a naphthyl group substituted with an amino group and a sulfo group as substituents. is particularly preferred.

Z in formula (3) represents the same substituent as explained for X in formula (2) above, and is preferably a nitro group.

Examples of the compound represented by formula (1) include the Kayaphor series (manufactured by Nippon Kayaku Co., Ltd.) and the Whitex series (manufactured by Sumitomo Chemical Co., Ltd.) such as Whitex RP. Furthermore, the compounds represented by formula (1) are exemplified below, but are not limited thereto.

(b) Dye having a biphenyl skeleton The above-mentioned dye having a biphenyl skeleton is preferably a compound represented by formula (4) or a salt thereof.

In the above formula (4), P and Q each independently include a nitro group, an amino group that may have a substituent, a carbonylamide group that may have a substituent, and a carbonylamide group that may have a substituent. naphthotriazole group, alkyl group having 1 to 20 carbon atoms which may have a substituent, vinyl group which may have a substituent, amide group which may have a substituent, It represents a good ureido group, an aryl group which may have a substituent, a carbonyl group which may have a substituent, and an amino group which may have a substituent, but is not necessarily limited to these. However, when the biphenyl skeleton has an azo group at the P position and/or the Q position, the fluorescence emission becomes significantly small, which is not suitable.

The compound represented by the above formula (4) is preferably a compound represented by the following formula (5).

In the above formula (5), j represents an integer from 0 to 2. The preferred substitution position of the (SO ₃ H)- group is not particularly limited, but when the vinyl group is the 1st position, the 2nd, 4th, and 6th positions are preferred, and the 2nd and 4th positions are particularly preferred.

In the above formula (5), R ₁ , R ₂ , R ₃ , and R ₄ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, an aralkyloxy group, and an alkenyloxy group. alkylsulfonyl group having 1 to 4 carbon atoms, an arylsulfonyl group having 6 to 20 carbon atoms, a carbonamide group, a sulfonamide group, and a carboxyalkyl group. The carboxyalkyl group may be the same as above.

Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, tert-butyl group, and cyclobutyl group.

Examples of the alkoxyl group having 1 to 4 carbon atoms include methoxy group, ethoxy group, propoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, and cyclobutoxy group.

Examples of the aralkyloxy group include aralkyloxy groups having 7 to 18 carbon atoms.

Examples of the alkenyloxy group include alkenyloxy groups having 1 to 18 carbon atoms.

Examples of the alkylsulfonyl group having 1 to 4 carbon atoms include methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, n-butylsulfonyl group, sec-butylsulfonyl group, tert-butylsulfonyl group, and cyclobutylsulfonyl group. It will be done.

Examples of the arylsulfonyl group having 6 to 20 carbon atoms include phenylsulfonyl group, naphthylsulfonyl group, biphenylsulfonyl group, and the like.

In the above formula (5), the preferred substitution positions of R ₁ to R ₄ are preferably the 2nd, 4th, and 6th positions when the vinyl group is the 1st position.

A method for synthesizing the polarized light-emitting dye represented by the above formula (5) will be described next. The polarized light-emitting dye represented by formula (5) can be produced by a known method, for example, by condensing 4-nitrobenzaldehyde-2-sulfonic acid with a phosphonate and then reducing the nitro group.

The compound represented by formula (5) is exemplified by the following compounds described in JP-A-4-226162.

The salts of the compounds represented by the above formulas (1) to (5) are salts formed with inorganic cations or organic cations. Inorganic cations include alkali metal cations such as lithium, sodium, and potassium, and ammonium ions (NH ₄ ⁺ ). Examples of the organic cation include organic ammonium represented by the following formula (D).

In formula (D), Z ₁ to Z ₄ each independently represent a hydrogen atom, alkyl, hydroxyalkyl, or hydroxyalkoxyalkyl, and at least one of Z ₁ to Z ₄ is a group other than a hydrogen atom.

Specific examples of Z ₁ to Z ₄ include C ₁ -C ₆ alkyl, preferably C ₁ -C ₄ alkyl, such as methyl, ethyl, butyl, pentyl, and hexyl; hydroxymethyl, 2-hydroxyethyl, 3-hydroxy HydroxyC ₁ -C ₆ alkyl, preferably hydroxyC ₁ -C ₄ alkyl, such as propyl, 2-hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl, and 2-hydroxybutyl; and hydroxyethoxymethyl, 2-hydroxy HydroxyC ₁ -C ₆ alkoxyC ₁ -C ₆ alkyl, preferably hydroxyC ₁ -C ₄ alkoxyC ₁ -C such as ethoxyethyl, 3-hydroxyethoxypropyl, 3-hydroxyethoxybutyl, and 2-hydroxyethoxybutyl ₄ alkyl and the like.

Among these inorganic cations and organic cations, cations such as sodium, potassium, lithium, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, and ammonium are more preferred. Examples include ions. Among these, lithium ions, ammonium ions, and sodium ions are more preferred.

Other polarized light-emitting dyes that can be used in the polarized light-emitting element include, for example:
C. I. Fluorescent Brighter 5,
C. I. Fluorescent Brighter 8,
C. I. Fluorescent Brighter 12,
C. I. Fluorescent Brighter 28,
C. I. Fluorescent Brighter 30,
C. I. Fluorescent Brighter 33,
C. I. Fluorescent Brighter 350,
C. I. Fluorescent Brighter 360,
C. I. Fluorescent Brighter 365,
Examples include. These fluorescent dyes may be free acids, or may be alkali metal salts (eg, Na salts, K salts, Li salts), ammonium salts, or salts of amines.

A polarized light-emitting element that emits polarized light can be obtained by orienting the polarized light-emitting dyes obtained above alone or in combination of two or more. When using two or more types of polarized light-emitting dyes in the polarized light-emitting element, it is possible to adjust the emission colors to various colors by adjusting the blending ratio between the polarized light-emitting dyes. For example, by adjusting the absolute values of the chromaticity a ^* value and b ^* value to be 5 or less, it is possible to make the polarized light emitted by the polarized light emitting element white. The above chromaticity a ^* value and b ^* value are determined according to JIS Z 8781-4:2013 based on the spectral distribution measured for the light emitted from the polarized light emitting element when the light is incident on the polarized light emitting element. It will be done. The object color display method defined in JIS Z 8781-4:2013 corresponds to the object color display method defined by the International Commission on Illumination (CIE). Measurement of chromaticity a ^* value and b ^* value is usually performed by irradiating the measurement sample with natural light, but in the specification and claims of this application, short wavelength light such as ultraviolet light is used in the polarized light emitting element. The chromaticity a ^* value and b ^* value can be confirmed by irradiating the light and measuring the emitted light. The absolute value of a ^* of the emitted light is 5 or less, preferably 4 or less, more preferably 3 or less, even more preferably 2 or less, particularly preferably 1 or less. Further, the absolute value of b ^* of the emitted light is 5 or less, preferably 4 or less, more preferably 3 or less, still more preferably 2 or less, particularly preferably 1 or less. If the absolute values of a ^* value and b ^* value are each independently 5 or less, the human eye can perceive it as white light, and if both of each is 5 or less, it is perceived as more preferable white light emission. I can do it. Because the emitted polarized light is white, it can be used as a natural light source like sunlight or as a light source with a paper white color, and has the advantage that it can be easily applied to displays that use color filters, etc. There is. As for the luminous intensity, if the light can be detected by the eye, there is no problem in applying it to displays. In particular, as a feature of the present application, it is important that the emitted light has a high degree of polarization and that the transmittance in the visible light region is high.

(2) Other pigments In addition to containing one or more pigments or salts thereof having a stilbene skeleton or biphenyl skeleton, the polarized light emitting element described above contains, for the purpose of color adjustment, etc., to the extent that the polarized light emission function is not inhibited. If necessary, one or more other organic dyes or other fluorescent dyes may be further included. Other organic dyes are not particularly limited, but are preferably highly dichroic and dyes that have little effect on the optical properties of dyes having a stilbene skeleton or a biphenyl skeleton. Other organic dyes include, for example, C.I. I. Direct Yellow 12, C. I. Direct Yellow 28, C. I. Direct Yellow 44, C. I. Direct Orange 26, C. I. Direct Orange 39, C. I. Direct Orange 71, C. I. Direct Orange 107, C. I. Direct Red 2, C. I. Direct Red 31, C. I. Direct Red 79, C. I. Direct Red 81, C. I. Direct Red 247, C. I. Direct Blue 69, C. I. Direct Blue 78, C. I. Direct Green 80, and C. I. Direct Green 59 etc. are mentioned. These organic dyes may be free acids, or may be alkali metal salts (eg, Na salts, K salts, Li salts), ammonium salts, or salts of amines.

When using the other organic dyes or other fluorescent dyes in combination, it is possible to select the dyes to be blended and adjust the blending ratio, etc., in order to adjust the desired color of the polarized light emitting element. Depending on the purpose of preparation, the blending ratio of organic dyes or fluorescent dyes is not particularly limited, but in general, the total amount of these other organic dyes or other fluorescent dyes per 100 parts by mass of the polarized light emitting element. is preferably used in a range of 0.01 to 10 parts by mass.

In addition to each of the dyes mentioned above, the dyeing solution may further contain a dyeing aid as required. Examples of the dyeing aid include sodium carbonate, sodium bicarbonate, sodium chloride, sodium sulfate (mirabilite), anhydrous sodium sulfate, and sodium tripolyphosphate, with sodium sulfate being preferred. The content of the dyeing aid can be arbitrarily adjusted by adjusting the above-mentioned immersion time and the temperature of the dyeing solution based on the dyeability of the dye used, but it is preferably 0.0001 to 10% by mass in the dyeing solution. It is preferably 0.0001 to 2% by mass, and more preferably 0.0001 to 2% by mass.

After the dyeing step, a pre-cleaning step may optionally be performed to remove the dyeing solution adhering to the surface of the substrate during the dyeing step. By performing the pre-cleaning step, it is possible to suppress the dye remaining on the surface of the substrate from migrating into the liquid to be treated next. In the preliminary cleaning step, water is generally used as the cleaning liquid. As for the cleaning method, it is preferable to immerse the dyed base material in a cleaning liquid, but on the other hand, cleaning can also be carried out by applying a cleaning liquid to the base material. The washing time is not particularly limited, but is preferably 1 to 300 seconds, more preferably 1 to 60 seconds. The temperature of the cleaning liquid in the preliminary cleaning step must be at a temperature at which the material constituting the base material does not dissolve, and the cleaning treatment is generally performed at a temperature of 5 to 40°C. Note that even if the pre-cleaning step is not performed, the performance of the polarized light emitting element is not particularly affected, so the pre-cleaning step can be omitted.

(Crosslinking process)
After the dyeing step or pre-washing step, the substrate can contain a crosslinking agent. The method for incorporating a crosslinking agent into a base material is preferably to immerse the base material in a treatment solution containing a crosslinking agent, and on the other hand, the treatment solution may be applied or coated onto the base material. A solution containing boric acid is used as the crosslinking agent in the treatment solution. The solvent in the treatment solution is not particularly limited, but water is preferred. The concentration of boric acid in the treatment solution is preferably 0.1 to 15% by mass, more preferably 0.1 to 10% by mass. The temperature of the treatment solution is preferably 30 to 80°C, more preferably 40 to 75°C. Further, the treatment time of this crosslinking step is preferably 30 seconds to 10 minutes, more preferably 1 to 6 minutes. Since the method for manufacturing a polarized light emitting element according to the present invention includes this crosslinking step, the polarization degree of the light emitted by the obtained polarizing element is high, and it exhibits high contrast as a display. This is an excellent effect that was completely unexpected from the function of boric acid, which was used in the prior art for the purpose of improving water resistance or light transmittance. In addition, in the crosslinking step, a fixing treatment may be further performed with an aqueous solution containing a cationic polymer compound, if necessary. This fixing treatment enables fixation of the dye in the polarized light emitting element. At this time, examples of cationic polymer compounds include cations, dicyanamide and formalin polymer condensates as dicyanic compounds, dicyandiamide/diethylenetriamine polycondensates as polyamine compounds, epichlorohydrin/dimethylamine addition polymers, dimethyl cationic compounds, etc. Diallylammonium chloride/dioxide ion copolymers, diallylamine salt polymers, dimethyldiallylammonium chloride polymers, allylamine salt polymers, dialkylaminoethyl acrylate quaternary salt polymers, and the like are used.

(Stretching process)
After passing through the above-mentioned crosslinking step, a stretching step is performed. The stretching step is performed by uniaxially stretching the base material in a certain direction, and may be performed by either a wet stretching method or a dry stretching method. The stretching ratio is preferably 3 times or more, more preferably 5 to 8 times.

In the wet stretching method, it is preferable to stretch the base material in water, a water-soluble organic solvent, or a mixed solution thereof. More preferably, the stretching treatment is performed while the base material is immersed in a solution containing at least one crosslinking agent. As the crosslinking agent, for example, boric acid used in the above-mentioned crosslinking agent step can be used, and preferably, the stretching treatment can be performed in the treatment solution used in the crosslinking step. The stretching temperature is preferably 40 to 70°C, more preferably 45 to 60°C. The stretching time is usually 30 seconds to 20 minutes, preferably 2 to 7 minutes. The wet stretching step may be performed in one stage or in multiple stages of two or more stages. Note that the stretching treatment may optionally be performed before the dyeing step, and in this case, the orientation of the dye can also be performed at the time of dyeing.

In the dry stretching method, when the stretching heating medium is an air medium, it is preferable to stretch the base material at a temperature of the air medium between room temperature and 180°C. Further, the humidity is preferably in an atmosphere of 20 to 95% RH. Examples of the heating method for the base material include, but are not limited to, an inter-roll zone stretching method, a roll heating stretching method, a hot rolling stretching method, and an infrared heating stretching method. The dry stretching step may be carried out in one stage of stretching or in multistage stretching of two or more stages.

(Washing process)
During the stretching process, a crosslinking agent may precipitate or foreign matter may adhere to the surface of the base material, so a cleaning process may be performed to clean the surface of the base material. The washing time is preferably 1 second to 5 minutes. As for the cleaning method, it is preferable to immerse the substrate in a cleaning liquid, but it is also possible to clean the substrate by applying or coating the cleaning liquid onto the substrate. Water is preferred as the cleaning liquid. The cleaning treatment may be performed in one step or in multiple stages of two or more steps. The temperature of the cleaning solution in the cleaning step is not particularly limited, but is usually 5 to 50°C, preferably 10 to 40°C, and may be room temperature.

In addition to the above-mentioned water, examples of the solvent for the solution or treatment liquid used in each of the above steps include dimethyl sulfoxide, N-methylpyrrolidone, methanol, ethanol, propanol, isopropyl alcohol, glycerin, ethylene glycol, propylene glycol, and diethylene glycol. , alcohols such as triethylene glycol, tetraethylene glycol or trimethylolpropane, and amines such as ethylenediamine and diethylenetriamine. The solvent of the solution or treatment liquid is most preferably water, although it is not limited thereto. Further, the solvents for these solutions or treatment liquids may be used alone or in a mixture of two or more.

(drying process)
After the washing step, a drying step of the base material is performed. The drying process can be carried out by natural drying, but in order to further increase the drying efficiency, it is possible to carry out by compressing with a roll, removing moisture from the surface with an air knife or water absorbing roll, etc. Furthermore, air drying can be carried out. It is also possible to do so. The temperature of the drying treatment is preferably 20 to 100°C, more preferably 60 to 100°C. The drying time is preferably 30 seconds to 20 minutes, more preferably 5 to 10 minutes.

The polarized light emitting device according to the present invention can be manufactured by the above method. The polarized light emitting element according to the present invention is an element that emits polarized light and exhibits polarized light in the ultraviolet region, and has high durability because the dichroic dye does not decompose even in high temperature or high humidity heat environments.

When the polarized light emitting element is irradiated with light in the ultraviolet to visible range, particularly light in the ultraviolet to near ultraviolet visible range, it uses the energy to emit polarized light in the visible light range. Since the light emitted by a polarized light emitting element is polarized light in the visible range, when the polarized light emitting element is observed through a general polarizing plate that has a polarizing function for light in the visible range, the visible light range By changing the angle of the axis of a general polarizing plate that has a polarizing function, it is possible to visually recognize the light on the axis that emits polarized light and the light on the axis that emits significantly less polarized light. The degree of polarization of the light emitted by the polarized light emitting element is 70% or more, preferably 80% or more, more preferably 90% or more, still more preferably 95% or more, particularly preferably 99% or more. Furthermore, a polarized light-emitting element using a polarized light-emitting dye having a biphenyl skeleton or a stilbene skeleton has high transmittance because it transmits light in the visible range. If the transmittance of the polarized light emitting element in the visible range is 50% or more in terms of luminous efficiency corrected transmittance, a liquid crystal display with significantly higher transmittance than conventional liquid crystal displays can be obtained. , preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, particularly preferably 90% or more. Since the polarized light emitting element used in the present application has high transmittance, absorption in the visible light region is small in the non-emission state, and a highly transparent polarized light emitting element can be obtained, using the polarized light emitting element is a preferred embodiment of the present application. one of.

[Polarized luminescent plate]
A polarized light emitting plate can also be obtained by providing a transparent protective layer on at least one surface of the polarized light emitting element. The transparent protective layer is used to improve the water resistance, handleability, etc. of the polarized light emitting element, and the transparent protective layer does not have any effect on the polarizing function exhibited by the polarized light emitting element.

The transparent protective layer is preferably a transparent protective film having excellent optical transparency and mechanical strength. The transparent protective layer is preferably a film having a layer shape that can maintain the shape of the polarized light emitting element, and is preferably a plastic film that has excellent thermal stability, moisture shielding properties, etc. in addition to transparency and mechanical strength. It is preferable that there be. Examples of materials for forming such a protective film include cellulose acetate films, acrylic films, fluorine films such as tetrafluoroethylene/hexafluoropropylene copolymers, polyester resins, and polyolefin resins. Alternatively, a film made of polyamide resin may be used, and triacetyl cellulose (TAC) film or cycloolefin film is preferably used. The thickness of the transparent protective layer is preferably in the range of 1 μm to 200 μm, more preferably in the range of 10 μm to 150 μm, and particularly preferably in the range of 40 μm to 100 μm. The method for producing the above-mentioned polarizing plate is not particularly limited, but for example, a polarizing plate can be produced by overlaying a transparent protective layer on a polarized light emitting element and laminating it according to a known recipe.

The polarized light emitting plate may further include an adhesive layer between the transparent protective layer and the polarized light emitting element for bonding the transparent protective layer and the polarized light emitting element. The adhesive constituting the adhesive layer is not particularly limited, but includes polyvinyl alcohol adhesives, urethane emulsion adhesives, acrylic adhesives, polyester-isocyanate adhesives, etc., and is preferably A polyvinyl alcohol adhesive is used. After bonding the transparent protective layer and the polarized light emitting element with an adhesive, the above polarized light emitting plate can be produced by drying or heat treating at an appropriate temperature.

Further, the polarized light emitting plate may optionally include various known functional layers such as an antireflection layer, an antiglare layer, and an additional transparent protective layer on the exposed surface of the transparent protective layer. When producing such layers with various functionalities, it is preferable to apply materials with various functionalities to the exposed surface of the transparent protective layer. It is also possible to attach it to the exposed surface of the transparent protective layer.

Examples of the further transparent protective layer include acrylic-based, polysiloxane-based, etc. hard coat layers, urethane-based protective layers, and the like. Further, in order to further improve the single transmittance, an antireflection layer can be provided on the exposed portion of the transparent protective layer. The antireflection layer can be formed, for example, by depositing or sputtering a substance such as silicon dioxide or titanium oxide on the transparent protective layer, or by thinly applying a fluorine-based substance on the transparent protective layer.

By installing the polarized light emitted from the polarized light emitting element or the polarized light emitting plate so that it emits polarized light in a direction perpendicular to the reflective medium (emit P polarized light), reflection in the horizontal reflective medium can be attenuated. A preferred form of the light source of the present application can be provided.

By arranging the polarized light emitting element or the polarized light emitting plate so that polarized light is emitted in a direction perpendicular to the reflective medium, it can be used as a light source that can emit light that can suppress reflection. It is possible to provide images and characters by processing a polarized light emitting plate or combining it with a liquid crystal cell, etc., but it is also possible to change the phase of the emitted polarized light by using a medium that controls the phase of polarized light. It becomes possible to convert not only linearly polarized light but also to various polarized light and wavelengths such as circularly polarized light and elliptically polarized light, and to display characters and images, polarized light emitting elements or One preferable form of the present invention is to use a medium that controls the phase together with a polarized light emitting plate. Examples of the medium that controls the phase include a case where a retardation plate (also called a wave plate, a retardation film, etc.) is dynamically driven, a liquid crystal cell that is controlled by electrically driving the liquid crystal, etc. . In particular, it is preferable to use a liquid crystal cell whose phase can be electrically controlled as the phase controlling medium. Light has the properties of particles and waves, but when light is expressed as a wave, it means that the phase of the wave can be controlled. When focusing on polarization performance, for example, a wave plate is an optical functional element that gives a predetermined phase difference to linearly polarized light, and polarization is different from light on a specific axis to light on other axes (for example, 90°). , it is possible to provide different phases. That is, by providing a retardation plate on the optical path of one polarized light, it becomes possible to polarize the light with the opposite axis, or to add circularly polarized light, elliptically polarized light, etc. Therefore, a retardation plate is an element that can change the state of polarization of incident light by creating a phase difference between two orthogonal polarization components using an oriented birefringent material (e.g., stretched film). I can say that. As a specific application of this wavelength plate, for example, if the wavelength of a specific light is λ, by setting the slow axis of the λ/2 retardation plate at 45 degrees with respect to the axis of polarization, The linearly polarized light incident on the wave plate (retardation plate) is rotated by 90 degrees, and can be output as polarized light having a polarization axis perpendicular (90 degrees) to the incident polarization axis. Additionally, if the slow axis of a λ/4 retardation plate is set at 45° to the axis of polarization, the linearly polarized light incident on the wave plate (retardation plate) will be emitted as circularly polarized light. possible. In recent years, depolarizing films have also been sold, making it possible to eliminate emitted polarized light. Examples of the depolarizing film include "SRF manufactured by Toyobo Co., Ltd.". The transmittance of such a retardation plate is preferably 50 to 99%, preferably 70 to 99%, and more preferably 80 to 99%.

The polarized light-emitting element and polarized light-emitting plate used in this application have absorption anisotropy in the ultraviolet to near-ultraviolet-visible region, that is, have a polarization function in the ultraviolet region, so the absorption anisotropy converts the light into fluorescent light. The amount of light emitted from the polarized light emitting element can be controlled by the amount of absorbed light that is polarized along the irradiated axis. That is, the polarized light emitting device and polarized light emitting plate described in the present application can control visible light emission by irradiating light from a light-inducing source, such as ultraviolet polarized light, to the light absorption axis of the polarized light emitting device or polarized light emitting plate. . Specifically, when the polarization axis of the light in the ultraviolet region emitted from the light-inducing source matches the ultraviolet light absorption axis of the polarized light emitting element and the polarized light emitting plate, polarized light is emitted. If the polarization axis of the incident light in the ultraviolet region is different from the ultraviolet absorption axis of the polarized light emitting element and the polarized light emitting plate, no polarized light is emitted. In other words, using the polarized light emitting device and the polarized light emitting plate of the present application as a light source is preferable because the display can be controlled by light in the ultraviolet region, that is, light that does not affect visibility, and does not affect the display necessary for visibility. .

As a polarizing plate that can control light in the ultraviolet region, for example, a polarizing plate using iodine or a dichroic dye described in International Publication No. 2005/015275 can be used. When a layer or film is provided to impart a protective function to the polarizing plate, it is preferable to laminate it with a film that does not have an ultraviolet absorption ability, or to provide a layer that does not have an ultraviolet absorption ability. Furthermore, a wire grid polarizing plate that can control polarization in the ultraviolet region may be used. It is preferable to use a dye-based polarizing plate described in International Publication No. 2005/015275 etc., which has low absorption in the visible light region and high transmittance. A polarizing plate that can produce polarized light in the ultraviolet region, a polarized light emitting element used in the present invention, a polarized light emitting plate, and a medium that can dynamically control the phase difference that can control polarized light in the ultraviolet region, specifically By using a liquid crystal cell in the structure, it is possible to obtain a light source or display device of the present invention that can display using polarized light in the ultraviolet region and has extremely high transparency.

By providing a light source or a display device that emits polarized light in the visible light range so that vertically polarized light is incident when irradiating light onto the light-reflecting medium, it is possible to It is possible to provide a display device that can prevent erroneous recognition due to erroneous recognition, and erroneous operation due to erroneous recognition in a safety device that recognizes light or motion.

The light source or display device of the present invention can be suitably used particularly in vehicles and ships. For example, it is possible to provide light with less reflection to drivers and light-sensing devices, and to provide highly anti-glare light sources and display devices. This is preferable because it provides a display device that can prevent malfunctions.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but these are merely illustrative and do not limit the present invention in any way. Further, "%" and "parts" described below are based on mass unless otherwise specified. In addition, in each structural formula of the compound used in each Example and Comparative Example, the acidic functional group such as a sulfo group is described in the form of a free acid.

(Polarizer)
The display of the present application was manufactured using SKN-18243P (manufactured by Polatechno Co., Ltd.) as a general polarizing plate. A general polarizing plate is a polarizing plate product that has a high polarizing function in the visible region and extremely low transmittance of light in the ultraviolet region.

(Synthesis example 1)
35.2 parts of commercially available 4-amino-4'-nitrostilbene-2,2'-disulfonic acid was added to 300 parts of water, stirred, and adjusted to pH 0.5 using 35% hydrochloric acid. 10.9 parts of a 40% aqueous sodium nitrite solution was added to the obtained solution, and the mixture was stirred at 10°C for 1 hour, followed by the addition of 17.2 parts of 6-aminonaphthalene-2-sulfonic acid, and the mixture was diluted with a 15% aqueous sodium carbonate solution. After adjusting the pH to 4.0, the mixture was stirred for 4 hours. 60 parts of sodium chloride was added to the resulting reaction solution, and the precipitated solid was separated by filtration and further washed with 100 parts of acetone to obtain 124.0 parts of a wet cake of the intermediate compound of formula (6). .

62.3 parts of the obtained dry powder of formula (6) was added to 300 parts of water and stirred, and the pH was adjusted to 10.0 using a 25% aqueous sodium hydroxide solution. To the obtained solution were added 20 parts of 28% aqueous ammonia and 9.0 parts of copper sulfate pentahydrate, and the mixture was stirred at 90°C for 2 hours. 25 parts of sodium chloride was added to the resulting reaction solution, and the precipitated solid was separated by filtration and further washed with 100 parts of acetone to obtain 40.0 parts of a wet cake of the compound of formula (7). By drying this wet cake with a hot air dryer at 80° C., 20.0 parts of a compound (λmax: 376 nm) of the following formula (7) was obtained.

(Preparation of polarized light emitting device)
A polyvinyl alcohol film (manufactured by Kuraray Co., Ltd., VF-PS#7500) having a thickness of 75 μm was immersed in warm water at 40° C. for 3 minutes to swell the film. The film obtained by swelling was mixed with 1.0 parts by weight of the 4,4'-bis-(sulfostyryl)biphenyl disodium aqueous solution (Tinopal NFW Liquid manufactured by BASF) described in Compound Example 5-1 and in Synthesis Example 1. The obtained compound (7) was immersed in a 45° C. aqueous solution containing 0.3 parts by weight, 1.0 parts by weight of Glauber's salt, and 1500 parts by weight of water for 4 minutes. The obtained film was stretched 5 times for 5 minutes at 50° C. in a 3% aqueous boric acid solution. The film obtained by stretching was washed with water at room temperature for 20 seconds while maintaining the tensioned state, and dried to obtain a polarized light emitting device.

(Preparation of polarized light emitting plate using polarized light emitting elements)
A triacetyl cellulose film (ZRD-60 manufactured by Fuji Film Co., Ltd.) containing no ultraviolet absorber was treated in a 1.5N aqueous sodium hydroxide solution at 35°C for 10 minutes, washed with water, and then dried at 70°C for 10 minutes. Ta. The triacetyl cellulose film obtained by the alkali treatment was laminated on both sides of the polarized light emitting element via an aqueous solution containing 4% polyvinyl alcohol resin (NH-26, manufactured by Nippon Vinegar Vipoval Co., Ltd.), and dried at 70°C for 10 minutes. A polarized light emitting plate was obtained. When this polarized light emitting plate was irradiated with ultraviolet rays, it emitted white light, and when the light emission was further confirmed through a polarizing plate, white polarized light was emitted in the stretching axis direction during processing of the polarized light emitting element. It was confirmed that polarized light was not emitted in the non-stretched axis.

(Preparation of ultraviolet region polarizing element)
A polyvinyl alcohol film (manufactured by Kuraray Co., Ltd., VF-PS#7500) having a thickness of 75 μm was immersed in warm water at 40° C. for 3 minutes to swell the film. The film obtained by swelling was treated with C.I. I. It was immersed for 4 minutes in a 45° C. aqueous solution containing 0.2 parts of Direct Yellow 28, 1.5 parts of Glauber's salt, and 1500 parts of water. The obtained film was immersed in a 3% boric acid aqueous solution at 50° C. for 5 minutes and stretched 5 times. The film obtained by stretching was washed with water at room temperature for 20 seconds while maintaining tension, and dried to obtain an ultraviolet polarizing element having the highest degree of polarization at 408 nm and polarization between 340 nm and 415 nm.

(Preparation of ultraviolet region polarizing plate)
A triacetyl cellulose film (ZRD-60 manufactured by Fuji Film Co., Ltd.) containing no ultraviolet absorber was treated with a 1.5N aqueous sodium hydroxide solution at 35°C for 10 minutes, washed with water, and then dried at 70°C for 10 minutes. I let it happen. The triacetylcellulose film obtained by the alkali treatment was laminated on both sides of an ultraviolet polarizing element with an aqueous solution containing 4% polyvinyl alcohol resin (NH-26, manufactured by Nippon Vinegar Vipoval Co., Ltd.), and then heated at 70°C for 10 minutes. It was dried for 1 minute to obtain a polarizing plate. Hereinafter, this polarizing plate will be referred to as an ultraviolet region polarizing plate.

The obtained polarizing plate, polarized luminescent plate, and ultraviolet region polarizing plate were evaluated as follows.

[evaluation]
(a) Single transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc
The single transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc of each measurement sample were measured using a spectrophotometer (“U-4100” manufactured by Hitachi, Ltd.). Here, the single transmittance Ts is the transmittance of each wavelength when measuring one measurement sample. The parallel transmittance Tp is the spectral transmittance of each wavelength measured by superimposing two measurement samples so that their absorption axes are parallel. The orthogonal transmittance Tc is a spectral transmittance measured by overlapping two polarizing plates such that their absorption axes are perpendicular to each other. Measurements were performed over wavelengths from 220 to 780 nm.
(b) Degree of polarization ρ
The polarization degree ρ of each measurement sample was determined by substituting the parallel transmittance Tp and the orthogonal transmittance Tc into the following formula (I).
(Number 1)
ρ={(Tp-Tc)/(Tp+Tc)} ^1/2 ×100...Formula (I)
(c) Single transmittance Ys corrected to visibility
The single transmittance Ys of each measurement sample is calculated based on the luminous efficiency according to JIS Z 8722:2009, with respect to the single transmittance Ts obtained at predetermined wavelength intervals dλ (here, 5 nm) in the wavelength range of 400 to 700 nm in the visible range. This is the corrected transmittance. Specifically, it was calculated by substituting the single transmittance Ts into formula (I). In addition, in the following formula (V), Pλ represents the spectral distribution of the standard light (C light source), and yλ represents the 2-degree visual field color matching function.

(Number 2)

The individual transmittance at 375 nm (Ts 375), the degree of polarization at 375 nm (ρ 375), the transmittance corrected to the visibility (Ys), and the visibility of each of the obtained polarized light emitting plate, ultraviolet polarizing plate, and polarizing plate. Table 1 shows the degree of polarization (ρy) corrected for sensitivity. The obtained polarization functions in the ultraviolet light region and visible light region can be seen.

(d) Measuring the polarization of the emitted light A UV LED 375nm hand light type black light (PW-UV943H-04 manufactured by Nichia Chemical Industries, Ltd.) was used as the light triggering source, and the light triggering source was UV transparent and visible cut. A filter ("IUV-340" manufactured by Isuzu Seiko Glass Co., Ltd.) was installed to cut visible light. On top of that, a polarizing plate ("SKN-18043P" manufactured by Polatechno, thickness 180 μm, Ys is 43%) having a polarizing function in the visible light region and the ultraviolet light region was placed, and each measurement sample, that is, a polarized light emitting plate, Install the ultraviolet polarizing plate and the polarizing plate, and measure the polarized light emitted by the polarizing plate, the ultraviolet polarizing plate, and the polarizing plate using a spectral irradiance meter (“USR-40” manufactured by Ushio Inc.) did. That is, the light from the light-induced source passes through an ultraviolet transmission/visible cut filter, a polarizing plate having a polarizing function in the visible light region and the ultraviolet light region, and each measurement sample (polarized light emitting plate, ultraviolet region polarizing plate, polarizing plate). , passed in this order, and was placed so that the polarized light was incident on the spectroradiometer. At that time, the spectral luminescence amount of each wavelength measured by superposing the absorption axis of the measurement sample so that the absorption axis where the ultraviolet ray absorption is maximum is parallel to the absorption axis direction of the ultraviolet/visible polarizing plate is Lw (weak emission axis). , superimpose the measurement sample so that the absorption axis where the ultraviolet absorption is maximum is perpendicular to the absorption axis direction of a polarizing plate (“SKN-18043P” manufactured by Polatechno) that has a polarizing function in the visible light region and the ultraviolet light region. Lw and Ls were measured using the spectral luminescence amount of each wavelength measured as Ls (strong emission axis). Visible light region when the absorption axes of each measurement sample, i.e., a polarizing light emitting plate, an ultraviolet region polarizing plate, a polarizing plate and a polarizing plate having a polarizing function in the visible light region and the ultraviolet light region, are parallel and orthogonal. By checking the energy amount of the emitted light, the amount of emitted light of polarized light in the visible light region of 400 nm to 700 nm was evaluated.

Table 2 shows Ls and Lw of each polarizing plate obtained at each wavelength of 460 nm, 550 nm, 610 nm, and 670 nm.

As shown in Table 2, a high Ls value has been detected for the polarized light emitting plate, and the difference between the Ls value and the Lw value is also significant at the four measured wavelengths. It can be seen that the emitted light has a polarizing function. Furthermore, it can be seen that the difference between the Lw value and the Ls value is more significant at each wavelength, and that the sample has good contrast. In addition, the chromaticity a ^* value and b ^* value at Ls of the polarized light emitting plate determined according to JIS Z 8781-4:2013 were 0.68 for a ^* value and -1.2 for b ^* value. . From this, it can be seen that the polarized light emitting plate emits white light. On the other hand, it can be seen that the ultraviolet polarizing plate and the polarizing plate did not emit light even when irradiated with light from a light-induced source.

[Example 1]
A white LED light was used as the light induction source, and SKN-18243P (manufactured by Polatechno Co., Ltd.) was used as a general polarizing plate, with its absorption axis in the horizontal direction with respect to the mirror-surfaced plastic (polycarbonate plastic plate) that was the reflective medium. A polarizing plate was arranged as shown in FIG. When the light from the light source thus obtained was irradiated onto a reflective medium, the visibility of the reflected light from the reflective medium was significantly reduced, so when the light from the light source is reflected from the reflective medium, it is significantly suppressed. That's what I found out.

[Comparative example 1]
A white LED light was used as the light-inducing source, and SKN-18243P (manufactured by Polatechno Co., Ltd.) was used as a general polarizing plate, with its absorption axis perpendicular to the mirror-surfaced plastic (polycarbonate plastic plate) that was the reflective medium. The polarizing plates were arranged so that horizontally polarized light (S-polarized light) was emitted. When the resulting light was irradiated onto a reflective medium, significant reflection of the light was observed despite passing through a polarizing plate.

[Example 2]
The polarized light emitting plate was arranged so that the light emitting axis of the polarized light was emitted in a direction perpendicular to the reflective medium of mirror-surfaced plastic (polycarbonate plastic plate) so that polarized light (P-polarized light) was emitted, and the light source of the present invention was used. The polarized light emitting plate was irradiated with ultraviolet light (UV LED 375 nm hand light type black light (PW-UV943H-04 manufactured by Nichia Chemical Industries, Ltd.)) as a light trigger source from the direction of viewing. . At that time, a visible light cut filter (IUV-340 manufactured by Isuzu Glass Co., Ltd.) was used at the light emitting part of the black light to prevent visible light from being emitted, and the polarized light was emitted from the polarized light emitting plate. The polarized light thus obtained was irradiated onto a plastic mirror surface, and the reflected light reflected from the plastic plate was observed. The visibility of the reflected light emitted from the light source of the present application was significantly reduced. From this, it was found that by installing a film that emits transparent polarized light so that it emits vertically polarized light, it was possible to create a light source that suppresses reflection even though it is a transparent film. The direction in which the polarized light emitting plate is irradiated with the ultraviolet rays from the light-inducing source is not limited to the direction from which it is viewed, as long as the ultraviolet light can be irradiated from any direction. It has been found that a light source that can be suppressed can be obtained.

[Comparative example 2]
The polarized light emitting axis of the polarized light emitting plate was arranged so that horizontally polarized light (S polarized light) was emitted with respect to a mirror-surfaced plastic (polycarbonate plastic plate) serving as a reflective medium. The polarized light emitting plate was irradiated with ultraviolet light (UV LED 375 nm hand light type black light ("PW-UV943H-04" manufactured by Nichia Chemical Industries, Ltd.)) as a light inducing source from the direction in which the polarized light emitting plate was viewed. At that time, a visible light cut filter (IUV-340, manufactured by Isuzu Glass Co., Ltd.) was used at the light emitting part of the black light to prevent visible light from being emitted, and the light was irradiated to emit polarized light. When the obtained polarized light was irradiated onto a plastic mirror surface and the reflected light reflected from the plastic plate was confirmed, the reflected light of the emitted light was sufficiently confirmed. For this reason, even if a film that emits polarized light is installed so as to emit polarized light in the horizontal direction, a light source that can suppress reflection could not be obtained.

[Example 2A]
In Example 2, an LED light as a natural light emitting device having the same amount of light as a light source with the polarized light emitting axis of the polarized light emitting plate vertically polarized (P polarized light) was irradiated onto a polycarbonate plastic (reflective medium) that was a mirror surface. When doing so, assume that the angle of incidence of light is 0° in the direction perpendicular to the reflective medium and the amount of reflected light is 1, and when the angle of incidence of light is changed with respect to the reflective medium, the amount of reflected light from the reflective surface is measured and shown. The results shown in 3 were obtained. At that time, the amount of reflected light from a natural light emitting device (white LED light) and the amount of reflected light of light polarized perpendicularly to the polarized light emission axis of the polarized light emitting plate (P-polarized light) are applied to a polycarbonate plastic mirror surface. The amount of reflected light when light was incident was compared, and the results shown in Table 3 below were obtained. The amount of reflected light is measured by measuring the reflected light using a luminance meter (CA-2000 manufactured by Konica Minolta), and measuring the luminance using natural light (white LED) or the luminance at a position opposite to the light source through a reflective medium. The meter was installed at the same angle as the light incident angle, and the amount of reflected light was measured.
The results are shown below.

The reflectance of light polarized perpendicular to the reflective surface is 3.6 times lower than natural light at a tilt angle of 40 degrees, and about 67 times lower at a tilt angle of 70 degrees. It was found that the reflectance of light polarized in the direction perpendicular to the reflecting surface was 0.008, meaning that the amount of reflected light was infinitely small. This shows that reflection can be significantly suppressed when the light from the light source of the present invention is emitted onto a reflective medium.

[Example 2B]
In Example 2, the polarized light emitting axis of the polarized light emitting plate was arranged so that polarized light (S polarized light) was emitted in a direction parallel to the mirror surface of polycarbonate plastic (reflection medium), and the polarized light emitting axis was 45 A retardation plate made of polycarbonate resin having a retardation value of 270 nm at a wavelength of 540 nm was laminated so that the retardation value was 270 nm at a wavelength of 540 nm. Note that the retardation plate having a retardation value of 270 nm is a film that functions as a 1/2λ retardation plate at a wavelength of 540 nm, and has a transmittance of 92% or more at a wavelength of 380 nm to 780 nm. Using. The light emitted from the polarized light emitting plate is reflected and irradiated with ultraviolet light from a light-inducing source (UV LED 375nm hand light type black light (PW-UV943H-04 manufactured by Nichia Corporation)) from a visible direction. went. At that time, a visible light cut filter (IUV-340 manufactured by Isuzu Glass Co., Ltd.) was used at the light emitting part of the black light to prevent visible light from being emitted, and the polarized light was emitted from the polarized light emitting plate. The obtained polarized light was irradiated onto a mirror-like polycarbonate plastic as a reflective medium from an angle of 60° when the vertical direction of the reflective medium was set to 0°, and the reflected light reflected from the plastic plate was observed. . As a result, the visibility of the reflection of light emitted from the light source was significantly reduced. From this, even if a polarized light emitting element or a polarized light emitting plate that emits transparent polarized light is installed so as to emit polarized light in a direction parallel to the reflective medium, a film or the like having a retardation value of 1/2λ is used. By doing this, it was found that the polarized light emitted by the polarized light emitting plate changed from polarized light parallel to the reflective medium (S polarized light) to polarized light perpendicular to the reflective medium (P polarized light), thereby making it possible to create a light source that suppresses reflection. It has been found that the direction in which the polarized light-emitting plate is irradiated with ultraviolet light, which is a light-inducing source, is not limited to the viewing direction, and by irradiating light from any direction, a light source that suppresses reflection can be obtained.

[Example 2C]
In Example 2, the polarized light emitting axis of the polarized light emitting plate was arranged so that polarized light (P polarized light) was emitted perpendicularly to the polycarbonate plastic plate (reflection medium), which was a mirror surface, and A retardation plate made of polycarbonate resin having a retardation value of 135 nm at a wavelength of 540 nm was laminated so that the angle was 45°. In addition, the retardation plate having a retardation value of 135 nm is a film that functions as a 1/4λ retardation plate at a wavelength of 540 nm, and has a transmittance of 92% or more at a wavelength of 380 nm to 780 nm. Using. The polarized light emitting plate is used as a light source (UV LED 375nm hand light type black light (Nichia Chemical Co., Ltd. Ultraviolet light irradiation was performed using "PW-UV943H-04" (manufactured by Kogyo Co., Ltd.). At that time, a visible light cut filter (manufactured by Isuzu Glass Co., Ltd., IUV-340) was used to prevent visible light from being emitted) to the light emitting part of the black light, and polarized light was emitted from the light source of the present invention. The polarized light obtained from the light source is irradiated onto a mirror-like polycarbonate plastic as a reflective medium from an angle of 2° when the vertical direction of the reflective medium is 0°, and the light reflected from the plastic plate is Using a polarizing plate laminated with a film having a retardation value of 135 nm at an angle of 45° to the absorption axis, from the polarizing plate side (the position of the polarizing plate) at an angle of ±10° to the perpendicular direction of the reflective medium. (with the retardation plate facing the reflective medium). As a result, it was found that the visibility of the reflected light from the light source was significantly reduced. From this, a polarized light emitting element or a polarized light emitting plate that emits polarized light even though it is a transparent film is installed so as to emit polarized light in the direction perpendicular to the reflective medium, and a film having a retardation value of 1/4λ can be produced. It has been found that by using a light source that can suppress reflection when viewed through a polarizing plate. It has been found that the direction in which the polarized light emitting plate is irradiated with ultraviolet light is not limited to the direction in which it is viewed, but a light source that suppresses reflection can be obtained by irradiating light from any direction.

[Example 3]
The films were arranged so that the polarized light emitting axes of the polarized light emitting plates were at 90° to each other in adjacent patterns, and a light source that emits polarized light having a pattern was produced. The polarized light emitting plate was irradiated with ultraviolet light from a visible direction using a photo-inducing source (UV LED 375 nm hand light type black light (PW-UV943H-04 manufactured by Nichia Chemical Industries, Ltd.)). At that time, a visible light cut filter (IUV-340 manufactured by Isuzu Glass Co., Ltd.) was used at the light emitting part of the black light to prevent visible light from being emitted. Light emitted from a light source with the pattern was irradiated onto a plastic mirror surface, and the reflected light reflected from the plastic plate was observed. In Fig. 1, in the pattern element of the polarized light emitting plate held with a finger, the position held with the finger is the position where polarized light is emitted in the horizontal direction with respect to the reflective medium, and adjacent patterns are 90 degrees from each other from that point as a starting point. The film is placed so that At this time, all of the polarized light emitting plates making up the pattern are transparent and emit uniform light even though they have a pattern in which the polarized light emitting axes emit different polarized light in the horizontal and vertical directions. Ta. On the other hand, if you check the reflected light of the polarized light obtained therefrom, you will find that it has alternating patterns of reflection and patterns of suppressed reflection. Furthermore, when we checked the reflected light, we found that if the emission axis was emitting vertically polarized light, the reflection was suppressed and it functioned as a light source, but the emission axis was emitting horizontally polarized light. In some cases, the reflex was not suppressed (Fig. 1). This shows that the light source can provide light that can suppress reflections in a light source placed perpendicular to the reflective medium. It has been found that the direction in which the polarized light emitting plate is irradiated with ultraviolet rays from the photo-inducing source is not limited to the viewing direction, but a light source that suppresses reflection can be obtained by irradiating light from any direction.

[Comparative example 3]
In FIG. 1 in Example 3, the polarized light emission axis was set at an angle of 45°, and reflected light was observed. As a result, even though the polarized light emitting plate had the same pattern of polarized light emitting axes as in Example 3 (emitted polarized light so that adjacent patterns were at 90°), it was found that the polarized light obtained from the polarized light was reflected. However, as shown in Figure 2, reflection could not be suppressed.

[Example 4]
With the configuration of ultraviolet polarizing plate/liquid crystal cell/polarized light emitting plate, the polarized light emitted from the polarized light emitting plate is emitted perpendicularly to the polycarbonate plastic plate (reflection medium), which is a mirror surface. , we created a transparent liquid crystal panel. The liquid crystal panel had a transmittance of 87% and had high transparency. The liquid crystal panel is irradiated with ultraviolet light from the ultraviolet polarizing plate side using a photo-inducing source (UV LED 375 nm hand light type black light (PW-UV943H-04 manufactured by Nichia Corporation)). Ta. At that time, a visible light cut filter (IUV-340 manufactured by Isuzu Glass Co., Ltd.) was used at the light emitting part of the black light to prevent visible light from being emitted. The light emitted from the resulting liquid crystal panel displayed characters and images in accordance with the driving of the liquid crystal cell. When the light emitted from the liquid crystal panel was irradiated onto a mirrored plastic plate (reflective medium) and the reflected light reflected from the plastic plate (reflective medium) was observed, the reflection of light was significantly suppressed. From this, it was found that the display device of the present application that suppresses reflection that provides polarized light emission in the direction perpendicular to the reflective medium could be manufactured.

[Comparative example 4]
In Example 4, a transparent liquid crystal panel was produced in the same manner as in Example 4, except that the polarized light emitted from the polarized light emitting plate was emitted horizontally to a polycarbonate plastic plate (reflection medium) that was a mirror surface. A display device was created. When the light emitted from the obtained liquid crystal panel was irradiated onto a plastic mirror surface and the reflected light reflected from the plastic plate was confirmed, the reflection of light was not suppressed and the display device displayed on the reflective medium. The written text and images were clearly visible.

[Example 5]
In front of each LED lamp that emits red, green, blue, and white, which is a light-emitting device, polarized light (P-polarized light) is placed in the direction perpendicular to the mirror surface of the polycarbonate plastic plate (reflection medium). ) was arranged so as to emit light, and the display device of the present invention was manufactured. While each LED lamp that emits red, green, blue, and white colors emits light, ultraviolet light is emitted from the visible direction onto the polarized light emitting plate as a light trigger source (UV LED 375 nm hand light type black light (manufactured by Nichia Corporation) Ultraviolet light irradiation was performed using "PW-UV943H-04"). At that time, a visible light cut filter (IUV-340 manufactured by Isuzu Glass Co., Ltd.) was used at the light emitting part of the black light to prevent visible light from being emitted. The resulting emitted light was irradiated onto a polycarbonate plastic mirror as a reflective medium from an angle of 60° when the vertical direction of the reflective medium was set to 0°, and the reflected light reflected from the plastic plate was observed. As a result, while the light from each LED lamp that emits red, green, blue, and white is sufficiently reflected on the reflective medium, the visibility of the reflected light emitted from the light source of the present invention against the reflective medium is low. decreased significantly. From this, it has been found that by using the light source of the present application on a reflective medium together with an LED lamp, a display device that can emit both reflected light and light whose reflection should be suppressed can be obtained. This means that by using light from a light-emitting device that does not have polarization and a light source that emits light polarized perpendicular to the reflective medium, the light that is reflected and the light that should be suppressed can be reduced, respectively. It has been found that the light source of the present invention capable of emitting light and a display device using the same can be manufactured. From this, it can be seen that the high transparency of the polarized light emitting plate used in the light source of the present application does not reduce the amount of light reflected on the reflective medium of the light emitted from the light source without polarization.

From the above, when converting the light emitted from the light-inducing source of the present application into polarized light, or emitting polarized light using the light emitted from the light-inducing source, and irradiating the light onto a medium that reflects the light, By providing a light source that can provide polarized light in the visible range such that vertically polarized light is incident on a reflective medium, or an image display device, it is possible to prevent misidentification of people and to recognize light and movements. A display device can be provided that prevents malfunctions due to misrecognition in devices. Furthermore, by installing a transparent polarized light emitting element or a polarized light emitting plate so that the polarized light is emitted perpendicularly to the reflective medium, a light source or display device that can emit polarized light while having transparency can be created. It turns out that you can get Not only can these light sources or display devices suppress reflections when illuminated on reflective surfaces such as plastics or stones (e.g. marble), but they can also be used in cars, motorcycles, bicycles, or on roads. By using it for signage, billboards, etc., it is possible to provide light whose reflection should be suppressed even if there are puddles or snow in the environment. Further, it can similarly be used as a light source for ships or a display device, and can provide light that can suppress reflection of light on the water surface.

By using the light source or display device of the present application, we can provide light that can prevent malfunctions due to erroneous recognition without the need for conventional automatic safety devices or cameras to take measures to prevent malfunctions through image processing on the light-receiving side. sell. In addition, by using the light source or display device of the present application, it is possible to provide light that suppresses light reflection, which not only eliminates malfunctions due to erroneous recognition of automatic safety devices, but also improves visibility for people. It is possible to provide light that can suppress possible reflections. In addition, since the light does not reflect, it can be applied to take advantage of various advantages such as security and design.

Claims (6)

A display device comprising a light source comprising a light inducing source and a polarized light emitting element made of a hydrophilic polymer film adsorbing and orienting a polarized light emitting dye, the display device comprising:
The polarized light emitting element emits polarized light in the visible range using light in the ultraviolet to near ultraviolet visible range emitted from the light-inducing source, and the polarized light in the vertical direction is incident on a medium that reflects the light. arranged so that
A display device that prevents malfunctions caused by misrecognition in equipment that recognizes light and motion . The malfunction prevention display device according to claim 1, wherein the light transmittance of the polarized light emitting element is 40% or more and 100% or less. An optical system comprising the malfunction prevention display device according to claim 1 or 2, comprising a medium that reflects the light. The optical system according to claim 3, characterized in that it is used outdoors. The optical system according to claim 3, characterized in that it is used for a driving device. 4. The optical system according to claim 3, wherein the optical system is used for vehicles such as automobiles, motorcycles, and bicycles, or for ships.