KR20220112134A - Polarizing plate and optical display apparatus comprising the same - Google Patents

Abstract

Provided are a polarizing plate and an optical display apparatus including the same. The polarizing plate includes a first region and a second region included in an image display region. The first region includes a first layer. The first region has a polarization degree higher than 0% and less than or equal to 30% and a group transmittance of 20% to 90%. A difference in group transmittance between the first region and the second region is 10% or less.

Description

Polarizing plate and optical display including same

The present invention relates to a polarizing plate and an optical display device including the same.

A polarizing plate is included in an optical display device to display an image or to improve the quality of an image. A mobile display such as a cell phone may also perform a function of taking a picture or an image by having an image sensor such as a camera.

Recently, an optical display device in which an image sensor is disposed under a display panel without forming a hole in a polarizing plate has been developed. In this case, one region of the polarizing plate corresponding to the image sensor should be able to perform an image display function as well as a function of taking a picture or an image. Therefore, it is necessary to realize uniform screen quality between one region of the polarizing plate corresponding to the image sensor and one region of the polarizing plate not corresponding to the image sensor.

On the other hand, when taking a picture or video using a mobile display such as a cell phone, it is not taken only in one direction. That is, the mobile display has a rectangular shape and has a long axis direction (a long side direction of the mobile display) and a short axis direction (a short side direction of the mobile display). However, depending on the user, the long axis direction may be photographed, the mobile display may be rotated 90° to photograph the short axis direction, and the photograph may be taken in any direction other than the short axis direction or the long axis direction. In this case, since one region of the polarizing plate corresponding to the image sensor has a certain degree of polarization performance, the color or sharpness of the screen image may vary depending on the shooting direction. Therefore, it is necessary to make the color or sharpness of the screen image uniform regardless of the shooting direction.

Background art of the present invention is described in Japanese Patent Application Laid-Open No. 2014-081482 and the like.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polarizing plate capable of making the color or sharpness of a photo or image substantially the same regardless of a photographing direction.

Another object of the present invention is to provide a polarizing plate that can substantially equalize color or sharpness of a screen depending on a viewing direction when viewed with polarized sunglasses.

Another object of the present invention is to provide a polarizing plate capable of minimizing a difference in screen quality between a first area in which an image sensor is disposed and a second area in which an image sensor is not disposed.

Another object of the present invention is to provide a polarizing plate having excellent reliability.

One aspect of the present invention is a polarizing plate.

1. The polarizing plate has a first area and a second area included in an image display area, wherein the first area includes a first layer, wherein the first area has a polarization degree of more than 0% and 30% or less and a single transmittance 20% to 90%, and a difference in transmittance of a single unit between the first region and the second region is 10% or less.

In 2.1, the second region may have a polarization degree of 80% or more.

In 3.1-2, the polarizing plate may include a first polarizer region corresponding to the first region, a second polarizer region corresponding to the second region, and a polarizer including the first layer.

In 4.3, the first layer may be laminated on at least one surface of the first polarizer region.

In 5.3, the first polarizer region may include a polyvinyl alcohol-based film.

In 6.5, the first layer may have a lower single transmittance compared to the first polarizer region.

In 7.5, the laminate of the first polarizer region and the first layer may have a polarization degree of greater than 0% and 30% or less, and a single transmittance of 20% to 90%.

In 8.5, the thickness of the first layer may be 1% to 20% of the thickness of the first polarizer region.

In 9.1-8, the first layer may include an organic layer, an inorganic layer, or an organic/inorganic mixed layer.

In 10.1-9, the first layer may include at least one of a dye and a pigment.

In 11.3, a protective layer may be further formed on at least one surface of the polarizer.

The optical display device of the present invention includes the polarizing plate of the present invention.

The optical display device may include a display panel, the polarizing plate formed on the upper portion of the display panel, and an image sensor formed on the lower portion of the display panel, and the image sensor may be disposed under the first region of the polarizing plate.

The present invention provides a polarizing plate capable of making the color or sharpness of a photo or image substantially the same regardless of a photographing direction.

The present invention provides a polarizing plate that can substantially equalize color or sharpness of a screen depending on a viewing direction when viewed with polarized sunglasses.

The present invention provides a polarizing plate capable of minimizing a difference in screen quality between a first area in which an image sensor is disposed and a second area in which an image sensor is not disposed.

The present invention provides a polarizing plate having excellent reliability.

1 is a plan view of a polarizing plate according to an embodiment of the present invention.
2 is a cross-sectional view of a polarizer according to an embodiment of the present invention.
3 is a cross-sectional view of a polarizing plate according to an embodiment of the present invention.
4 is a cross-sectional view of an optical display device according to an embodiment of the present invention.

With reference to the accompanying drawings and embodiments, the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same names are used for the same or similar components throughout the specification. The length and size of each component in the drawings are for explaining the present invention, and the present invention is not limited to the length and size of each component described in the drawings.

In this specification, "upper" and "lower" are defined based on the drawings, and "upper" may be changed to "lower" and "lower" to "upper" depending on the viewing angle.

In this specification, "total transmittance (Ts)" and "polarization degree" mean values measured at a wavelength of 200 nm to 800 nm, preferably at a wavelength of 550 nm, respectively.

Regarding "single transmittance of the first region" in the present specification, the single transmittance of the first region is the same throughout the first region at the same wavelength. However, even at the same wavelength, when the single transmittance is not the same in the entire first region, the single transmittance of the first region means the average single transmittance.

Regarding "single transmittance of the second region" in the present specification, the second region has the same single transmittance in the entire second region at the same wavelength. However, even at the same wavelength, when the single transmittance is not the same in the entire second region, the single transmittance of the second region means the average single transmittance.

In the present specification, "average single transmittance" means an average value of the single transmittance in a region in which the average single transmittance is to be measured. For example, the average single transmittance may be obtained from an average value of the single transmittance obtained by arbitrarily designating a plurality of points among regions for measuring the average single transmittance.

When describing a numerical range in the present specification, "X to Y" means "X or more and Y or less (X≤ and ≤Y)".

The polarizing plate of the present invention includes an image display region and first and second regions formed in the image display region. When the polarizing plate is applied to an optical display device, a region corresponding to an image sensor (eg, a camera) of an optical display device is referred to as a first region, and a region other than the first region, that is, a region not corresponding to the image sensor, is a second region. It is said The first area may perform both an image or photo taking function and an image display function.

The "image display area" means an area in which an image is displayed among a screen implemented by an optical display device. When the polarizing plate is applied to the optical display device, the image display area may be included in 90% to 100%, preferably 100% of the polarizing plate. The optical display device will be described in more detail below.

The polarizing plate of the present invention is used in the optical display device to allow the color or sharpness of the screen image according to the direction to be substantially the same even if the shooting direction is changed when taking a picture or an image by the image sensor. In addition, the polarizing plate of the present invention can minimize the difference in screen quality between the first area and the second area. In addition, the polarizing plate of the present invention can provide high reliability at high temperature and high humidity.

A polarizing plate according to an embodiment of the present invention will be described with reference to FIG. 1 . 1 is a plan view of a polarizing plate according to an embodiment of the present invention.

Referring to FIG. 1 , the polarizing plate includes a first region 110 and a second region 120 . The first area 110 and the second area 120 may be included in the image display area of the optical display device.

The first area 110 is an area corresponding to the image sensor among the image display areas of the optical display device. Although not shown in FIG. 1 , when a polarizing plate is applied to an optical display device, an image sensor may be disposed under the first region 110 . The first region 110 may perform an image display function when the image sensor is not used, and may perform a photo or image capturing function when taking a picture or image using the image sensor.

The second region 120 is a region that does not correspond to the image sensor among the image display regions of the optical display device. Accordingly, the second area 120 may perform only an image display function, unlike the first area.

The polarization degree of the first region 110 is greater than 0% and less than or equal to 30%, specifically greater than 0% and less than or equal to 20%, and more specifically greater than or equal to 0% and less than or equal to 15%. In the above range, when an image sensor is not used, an image display function is performed, and when a picture or an image is taken by an image sensor, even if the shooting direction is changed, the color or sharpness of the screen image can be substantially the same depending on the shooting direction. . In addition, when the optical display device is viewed with polarized sunglasses, there is a problem in that the image changes a lot depending on the direction in which the image is viewed.

In general, polarization degree and single transmittance have a trade-off relationship with each other. Accordingly, when the polarization degree of the first region is significantly lowered to 30% or less, there is a problem in that the single transmittance of the first region becomes very high to more than 90%. If the single transmittance exceeds 90%, the difference in the single transmittance between the first and second areas is significantly increased, so that the difference in image brightness between the first and second areas becomes severe, and the quality of the image from the image display area may deteriorate. have.

On the other hand, the first region 110 has a transmittance of 20% to 90%, specifically 40% to 50%. Accordingly, in the image display function, the polarizing plate can minimize the difference in the brightness of the image between the first region and the second region and the difference in color uniformity and image quality when the shooting direction is changed.

The difference in the single transmittance between the first region 110 and the second region 120 is 10% or less, specifically, 0% to 10%, and 0% to 5%, so that the light transmission in the first region and the second region By making the values uniform with each other, the difference in screen quality between the first region and the second region can be reduced, and the difference in color uniformity and image quality can be minimized when the shooting direction is changed.

The second region 120 has a higher degree of polarization than the first region 110 . In one embodiment, the polarization degree of the second region may be 80% or more, for example, 90% to 100%. In the above range, the image quality in the image display area by the anti-reflection may be excellent.

The second region 12 may have a single transmittance of 20% to 90%, specifically 40% to 50%. In the above range, the image quality may be excellent.

By including the first layer in the first region, the polarizing plate may satisfy the difference between the single transmittance of the first region and the single transmittance between the first region and the second region while having the polarization degree of the first region. The polarizing plate of the present invention is characterized in that it has a first region having a polarization degree significantly lower than that of the second region and having a single transmittance substantially the same as that of the second region. Through this, the above-described effects of the present invention can be obtained.

In the polarizing plate, the first region may not include a hole formed in the polarizer. The first layer may allow the first region not including the hole formed in the polarizer to reach the above-mentioned single transmittance.

The polarizing plate includes a polarizer having a first polarizer region and a second polarizer region, and the polarizer further has a first layer laminated on the first polarizer region. The first layer is not included in the second polarizer region.

Hereinafter, a polarizing plate according to an embodiment of the present invention will be described with reference to FIG. 2 . 2 is a cross-sectional view of a polarizer among the polarizing plates according to an embodiment of the present invention.

Referring to FIG. 2 , the polarizer 10 includes a first polarizer region 11 , a second polarizer region 12 , and a first layer 20 , and the first layer 20 includes a first polarizer region 11 . ) is laminated on one side. Preferably, the first layer 20 may be laminated on the viewer side of the polarizer 10 , that is, the viewer side.

The first polarizer region 11 may correspond to the first region 110 of FIG. 1 , and the second polarizer region 12 may correspond to the second region 120 of FIG. 1 .

The first polarizer region 11 and the second polarizer region 12 are integrally formed with each other. The “integrally formed” refers to a state in which the first polarizer region is not directly formed by physical punching, and the first polarizer region and the second polarizer region are directly connected to each other.

The second polarizer region 12 has a higher degree of polarization than the first polarizer region 11 . In one embodiment, the polarization degree of the second polarizer region may be 80% or more, for example, 90% to 100%. In the above range, the image quality in the image display area by the anti-reflection may be excellent.

The second polarizer region 12 may have a single transmittance of 20% to 90%, specifically 40% to 50%. In the above range, the image quality may be excellent.

The polarization degree of the first polarizer region 11 may be greater than 0% and less than or equal to 30%, specifically, greater than or equal to 0% and less than or equal to 15%. In the above range, the polarization degree of the first region can be easily reached, so that the above-described effect can be obtained.

The first polarizer region 11 has a higher single transmittance than the first region 110 . However, the single transmittance of the first region 110 may be lower than the single transmittance of the first polarizer region 11 due to the first layer 20 . For example, the single transmittance of the first polarizer region 11 may be 80% or more and 100% or less.

The first layer 20 is laminated on at least one surface of the first polarizer region 11 . The first layer 20 may be laminated on one surface (top surface) of the first polarizer region 110 or on both surfaces (top surface and bottom surface) of the first polarizer region 110 .

The first layer 20 is formed in direct contact with the first polarizer region 11 , thereby helping to reduce the thickness of the polarizer and improve reliability of the polarizer due to moisture. The first polarizer region 11 is formed by light irradiation, and when external moisture penetrates into the first polarizer region 11, the dichroic material is restored to the state before light irradiation in the first polarizer region, thereby increasing the degree of polarization. can The first layer 20 may function as a reliability improving layer of the polarizer by improving the reliability of the polarizer by blocking the penetration of external moisture into the first polarizer region.

The first layer 20 may also act as a light transmittance control layer that lowers the single transmittance of the first region 110 of FIG. 1 . The first layer 20 has a lower single transmittance than the first polarizer region 11 . Accordingly, the first region may have a polarization degree of more than 0% and 30% or less and a single transmittance of 20% to 90%, preferably 40% to 50%.

The polarization degree of the laminate of the first polarizer region 11 and the first layer 20 may be greater than 0% and less than or equal to 30%, specifically, greater than or equal to 0% and less than or equal to 15%. In the above range, when an image sensor is not used, an image display function is performed, and when a picture or an image is taken by an image sensor, even if the shooting direction is changed, the color or sharpness of the screen image can be substantially the same depending on the shooting direction. . In addition, when the optical display device is viewed with polarized sunglasses, there is a problem in that the image changes a lot depending on the direction in which the image is viewed. In addition, when the retardation film is included in the polarizing plate, it is possible to provide an effect of preventing reflection of external light.

The laminate of the first polarizer region 11 and the first layer 20 may have a single transmittance of 20% to 90%, specifically, 40% to 50%. Through this, the polarizing plate can minimize the difference in image brightness between the first region and the second region in the image display function, and when the retardation film is included in the polarizing plate, it can also provide an effect of preventing reflection of external light.

In the polarizing plate of the present invention, the first polarizer region 11 and the laminate of the first layer 20 directly laminated on the first polarizer region 11 satisfy the above-described polarization degree and single transmittance range, respectively, so that one or both sides of the polarizer Even when the protective layer is not provided, the above-described effects of the present invention can be obtained, and even when the first polarizer region 11 is formed by light irradiation, the reliability of the polarizer can be improved.

The first layer 20 may have a single transmittance of 20% to 90%, specifically 30% to 70%. Within the above range, the single transmittance of the first region can be reached, and when the protective layer is formed on one surface of the polarizer, there is an effect of preventing reflection of external light, so that the screen quality difference between the first region and the second region can be minimized.

The first layer 20 may have a thickness of 0.1 μm to 10 μm, specifically, 0.1 μm to 5 μm. Within the above range, it is possible to provide a thinning effect of the polarizing plate without affecting the thickness of the polarizing plate.

The thickness of the first layer 20 may be 1% to 20%, specifically 5% to 20% of the thickness of the first polarizer region 11 . Within the above range, it is possible to provide an effect of increasing the transmittance of a single unit and an effect of preventing reflection of external light.

The first layer 20 is not limited in its forming material and its forming method as long as it can provide the above-mentioned functions. The first layer 20 may be an organic layer, an inorganic layer, or an organic/inorganic mixed layer.

In one embodiment, the first layer 20 may be an organic layer formed of a composition including at least one of a dye and a pigment. The dye or pigment has a color that does not affect the color of the polarizer and image quality, and may have a maximum absorption wavelength of 400 nm to 700 nm. Through this, since the first layer 20 has the above-described single transmittance, the single transmittance of the first region may be reached.

In another embodiment, the first layer 20 may be an inorganic layer formed by depositing or coating a material such as carbon black, or an organic layer formed by depositing or coating a material containing an organic black dye or organic black pigment. .

Hereinafter, the manufacturing method of a polarizer is demonstrated.

The polarizer forms a first polarizer region by preparing a polyvinyl alcohol-based film in which at least one dichroic material of iodine and a dichroic dye is dyed and stretched, and a portion of the polyvinyl alcohol-based film is subjected to a predetermined treatment, It may be manufactured by a method including forming a first layer on an upper surface and/or a lower surface of the first polarizer region. A region in which the polyvinyl alcohol-based film is not subjected to the treatment becomes a second polarizer region.

First, a step of preparing a polyvinyl alcohol-based film in which at least one dichroic material of iodine and a dichroic dye is dyed and stretched will be described.

The dyed and stretched polyvinyl alcohol-based film may be prepared by dyeing and stretching the polyvinyl alcohol-based film. The order of dyeing and extending|stretching in the manufacturing method of a polarizer is not restrict|limited. That is, the polyvinyl alcohol-based film may be dyed and then stretched, or dyed after stretching, or dyed and stretched at the same time.

As the polyvinyl alcohol-based film, a conventional polyvinyl alcohol-based film used in manufacturing a conventional polarizer may be used. Specifically, a film formed of polyvinyl alcohol or a derivative thereof may be used. Polyvinyl alcohol or its derivative may have a polymerization degree of 1000 to 5000, and a saponification degree of 80 mol% to 100 mol%. The thickness of the polyvinyl alcohol-based film may be 1 μm to 30 μm, specifically 3 μm to 30 μm, and in the above range, it can be used to manufacture a thin polarizer.

The polyvinyl alcohol-based film may be dyed, washed, and swelled before being stretched. By washing the polyvinyl alcohol-based film with water, foreign substances adhering to the surface of the polyvinyl alcohol-based film can be removed. By swelling the polyvinyl alcohol-based film, dyeing or stretching of the polyvinyl alcohol-based film can be improved. The swelling treatment may be performed by leaving the polyvinyl alcohol-based film in an aqueous solution in a swelling tank, as known to those skilled in the art. The temperature and swelling treatment time of the swelling tank are not particularly limited. The swelling tank may further include boric acid, inorganic acid, surfactant, and the like, and their content may be adjusted.

The polyvinyl alcohol-based film can be dyed by dyeing the polyvinyl alcohol-based film in a dyeing tank containing at least one of iodine and a dichroic dye. In the dyeing process, the polyvinyl alcohol-based film is immersed in a dyeing solution, and the dyeing solution may be an aqueous solution containing iodine and a dichroic dye. Specifically, iodine is provided from an iodine-based dye, and the iodine-based dye may include one or more of potassium iodide, hydrogen iodide, lithium iodide, sodium iodide, zinc iodide, lithium iodide, aluminum iodide, lead iodide, and copper iodide. . The dyeing solution may be an aqueous solution containing 1 wt% to 5 wt% of one or more of iodine and a dichroic dye. Within the above range, it may have a degree of polarization within a predetermined range to be used in a display device.

The temperature of the dyeing tank may be 20 °C to 45 °C, and the immersion time in the dyeing tank of the polyvinyl alcohol-based film may be 10 seconds to 300 seconds. In the above range, a polarizer having a high degree of polarization may be implemented.

By stretching the polyvinyl alcohol-based film in a stretching tank, the polyvinyl alcohol-based film may have polarizing properties by aligning at least one of iodine and a dichroic dye. Specifically, both dry stretching and wet stretching may be used for stretching. Dry stretching may be inter-roll stretching, compression stretching, hot roll stretching, and the like, and wet stretching may be performed in a wet stretching bath containing water at 35°C to 65°C. The wet stretching bath may enhance the stretching effect by further including boric acid.

The polyvinyl alcohol-based film may be stretched at a predetermined draw ratio, specifically, the total draw ratio may be 5 to 7 times, specifically 5.5 to 6.5 times, and cutting phenomenon of the polyvinyl alcohol-based film stretched in the above range , wrinkles, etc. can be prevented, and a polarizer with increased polarization degree and transmittance can be implemented. Stretching may be uniaxial stretching, and may be performed in single-stage stretching, but may be prevented from breaking while manufacturing a thin polarizer by performing multi-stage stretching such as 2-stage or 3-stage stretching.

In the above description, the polyvinyl alcohol-based film is dyed and then stretched in the order of stretching, but dyeing and stretching may be performed in the same reaction tank.

Before stretching the dyed polyvinyl alcohol-based film or after dyeing, the stretched polyvinyl alcohol-based film may be cross-linked in a crosslinking tank. Crosslinking is a process of making the polyvinyl alcohol-based film more strongly dyed with at least one of iodine and dichroic dye, and boric acid may be used as the crosslinking agent. In order to enhance the crosslinking effect, a phosphoric acid compound, potassium iodide, or the like may be further included.

The dyed and stretched polyvinyl alcohol-based film may be treated with a complementary color in a complementary color tone. Complementary color treatment is immersing the dyed and stretched polyvinyl alcohol-based film in a complementary color tone containing a complementary color solution containing potassium iodide. Through this, by lowering the color value of the polarizer and removing the iodine anion I ⁻ in the polarizer, durability can be improved. The temperature of the complementary color may be from 20 °C to 45 °C, and the immersion time for the complementary color of the polyvinyl alcohol-based film may be from 10 seconds to 300 seconds.

Next, the treatment may be applied to a portion of the polyvinyl alcohol-based film to form a first polarizer region.

A portion of the polyvinyl alcohol-based film may be irradiated with at least one of pulsed light by a Xenon Flash Lamp and a femtosecond laser, and the irradiated region may be the first polarizer region. In the present invention, the first polarizer region was formed by the above-described method to form the first layer.

Xenon Flash Lamp irradiates light in the form of pulses at a continuous wavelength of 200 nm to 800 nm, so that when compared to conventional femtosecond or picosecond lasers, when forming an area with a lower polarization compared to before irradiation, one or more of iodine and dichroic dye among the depolarization areas Damage to the dyed polyvinyl alcohol-based film can be lowered.

When irradiating pulsed light by the Xenon Flash Lamp, detailed irradiation conditions are: energy power of 300V to 500V, pulse period of 0.5Hz to 2Hz, irradiation time of 5ms (millisecond) to 15ms, and the number of irradiations is 1 to 10 it can be a meeting Within the above range, it may help to obtain the first polarizer region of the present invention. When irradiating the light source, a mask of a desired shape is placed in close contact with the dyed and stretched polyvinyl alcohol-based film, so that portions that do not need to depolarize can be controlled to maintain the corresponding light transmittance.

Femtosecond laser beam size (Beam Size) 10㎛ to 30㎛, pulse frequency (Pulse Frequency) 200kHz to 400kHz, energy density per pulse (Energy Density per Pulse) 0.1 to 0.5J / cm ² /Puls can be irradiated.

In one embodiment, the femtosecond laser includes at least two types of femtosecond lasers each selected from a wavelength region of 340 nm to 346 nm and a wavelength region of 510 nm to 520 nm.

Light in the wavelength region of 510 nm to 520 nm can resolve the polarization function in the irradiated region by decomposing the iodine and dichroic dye by transferring the iodine and the dichroic dye dyed in the polarizer from the ground state to the excited state. When at least two types of femtosecond lasers, each selected from a wavelength region of 340 nm to 346 nm and a wavelength region of 510 nm to 520 nm, are irradiated to the polarizer, the above-described polarization function is eliminated and the light transmittance is increased, and the high temperature, high humidity reliability of the polarizer or polarizer is increased. can

Specifically, in the wavelength region of 340 nm to 346 nm, a femtosecond laser having a wavelength of 340 nm, 341 nm, 342 nm, 343 nm, 344 nm, 345 nm, 346 nm, and preferably 343 nm may be selected. Specifically, in the wavelength region of 510 nm to 520 nm, a femtosecond laser having a wavelength of 510 nm, 511 nm, 512 nm, 513 nm, 514 nm, 515 nm, 516 nm, 517 nm, 518 nm, 519 nm, 520 nm, preferably 515 nm may be selected. Optimally, a femtosecond laser may be irradiated at a wavelength of 343 nm and a wavelength of 515 nm, respectively.

In one embodiment, the first polarizer region may be formed by pulsed light irradiation alone by a Xenon Flash Lamp or by femtosecond laser irradiation alone.

In another embodiment, the first polarizer region may be formed by a combination of pulsed light irradiation by a Xenon Flash Lamp and femtosecond laser irradiation. For example, the first polarizer region is irradiated with pulsed light by a Xenon Flash Lamp and irradiated with a femtosecond laser, or irradiated with a femtosecond laser and irradiated with pulsed light by a Xenon Flash Lamp, or pulsed light by a Xenon Flash Lamp and It can be formed by simultaneously irradiating a femtosecond laser. Preferably, after irradiating pulsed light by a Xenon Flash Lamp, a femtosecond laser is irradiated. However, the femtosecond laser should be irradiated under minimum irradiation conditions that do not affect the first polarizer region of the present invention.

The polarizer manufacturing method of the present invention further includes one or more of heat treatment and water washing treatment for the irradiated area after pulse light irradiation by a Xenon Flash Lamp or a combination of pulse light irradiation and laser irradiation by a Xenon Flash Lamp can do. The above treatment increases the reliability of the first polarizer region by blocking the polarization degree of the first polarizer region from being restored to the state before forming the first polarizer region when the first polarizer region is left at high temperature and/or high temperature and humidity for a long time. can help

The heat treatment may include treating the polarizer in which the first polarizer region is formed at 70° C. to 90° C. for 1 minute to 10 minutes. Within the above range, the reliability of the first polarizer region may be increased while minimizing the influence on the region other than the first polarizer region.

The water washing treatment may include contacting the polarizer in which the first polarizer region is formed in water at 30°C to 60°C for 1 minute to 10 minutes. The contacting treatment may be performed according to a conventional method known to those skilled in the art, such as immersing the polarizer in which the first polarizer region is formed in the water, or washing the polarizer with water.

Next, a polarizer may be manufactured by forming a first layer on an upper surface and/or a lower surface of the first polarizer region.

The first layer may be formed by depositing or coating an inorganic black dye including a dye, a composition including at least one of a pigment, an organic black dye, or carbon black on the upper surface and/or the lower surface of the first polarizer region. have. Deposition and coating methods may be performed by conventional methods known to those skilled in the art.

The polarizer 10 may have a thickness of 3 μm to 50 μm, specifically 3 μm to 30 μm. Within the above range, it can be used for a polarizing plate.

Referring to FIG. 3, a polarizing plate according to an embodiment of the present invention will be described. 3 is a cross-sectional view of a polarizing plate according to an embodiment of the present invention.

Referring to FIG. 3 , the polarizing plate 100 includes a polarizer 10 , a first protective layer 30 stacked on an upper surface of the polarizer 10 , and a second protective layer 40 stacked on a lower surface of the polarizer 10 . ) may be included. The polarizing plate includes a first region 110 and a second region 120 , and the first region 110 includes a first layer 20 .

Although not shown in FIG. 3 , the upper surface of the polarizer 10 may be on the observer side, and the lower surface of the polarizer 10 may be on the display panel side of the optical display device. Accordingly, an upper surface of the polarizer 10 may be a light exit surface of the polarizer, and a lower surface of the polarizer 10 may be a light incident surface of the polarizer.

The polarizer 10 and the first layer 20 are substantially the same as described above, respectively. Since the adhesive layer 50 is formed between the polarizer 10 and the first layer 20 and the first protective layer 30 , the first protective layer 30 may be adhered to the polarizer 10 . The adhesive layer 50 may be formed of a conventional water-based adhesive or a photocurable adhesive known to those skilled in the art. The adhesive layer 50 may have a thickness greater than that of the first layer 20 , and may have a thickness of 0.1 μm to 10 μm, specifically, 0.1 μm to 5 μm. Within the above range, it can be used for a polarizing plate.

The first protective layer 30 may be laminated on the upper surface of the polarizer 10 to protect the polarizer.

The first protective layer 30 may be a photocurable coating layer or a protective film. The photocurable coating layer may include a cured layer formed of a composition including a photocurable compound or a liquid crystal layer formed of a liquid crystalline polymer. As the protective film, a protective film commonly used as a protective film for a polarizer may be used. For example, the protective film is a polyester-based, cyclic polyolefin-based, polycarbonate containing cellulose-based, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, etc. containing triacetyl cellulose. Protective film made of at least one resin selected from the group consisting of, polyethersulfone, polysulfone, polyamide, polyimide, polyolefin, polyarylate, polyvinyl alcohol, polyvinyl chloride, and polyvinylidene chloride. may include

The first protective layer 30 may have a thickness of 1 μm to 100 μm, for example, 1 μm to 50 μm.

The second protective layer 40 may be laminated on the lower surface of the polarizer to protect the polarizer. The second protective layer 40 may provide an antireflection function to the polarizing plate by having a retardation within a predetermined range.

The second protective layer may be a single retardation layer type or a laminate in which a plurality of retardation layers are stacked.

In one embodiment, the second protective layer may include a first retardation layer. The first retardation layer may prevent reflection of external light by circularly polarizing the linearly polarized light emitted after the external light passes through the polarizer to improve screen quality.

The first retardation layer may have an in-plane retardation (Re) of 100 nm to 220 nm, specifically 100 nm to 180 nm, for example, a λ/4 retardation at a wavelength of 550 nm. In the above range, it is possible to obtain an effect of improving screen quality by lowering the reflectance for external light.

In another embodiment, the second protective layer may include the first retardation layer and the second retardation layer.

The second retardation layer may have an in-plane retardation (Re) of 225 nm to 350 nm at a wavelength of 550 nm, specifically 225 nm to 300 nm, for example, a λ/2 retardation. In the above range, it is possible to obtain an effect of improving screen quality by lowering the reflectance for external light.

In the present specification, the 'in-plane retardation (Re)' is Re = (nx - ny) x d (nx, ny is the slow axis direction and the fast axis direction of the retardation layer, respectively, the refractive index in the direction, d is the retardation layer can be calculated as the thickness of (unit: nm)).

The first retardation layer and the second retardation layer may be the photocurable coating layer or the protective film described in the first protective layer, respectively.

The second protective layer 40 may have a thickness of 1 μm to 100 μm, for example, 1 μm to 50 μm.

Hereinafter, an optical display device according to an embodiment of the present invention will be described.

The optical display device of the present invention includes the polarizing plate of the present invention. The optical display device may include an organic light emitting display device, a liquid crystal display device, preferably an organic light emitting display device.

Referring to FIG. 4 , the optical display device of the present invention will be described in more detail.

Referring to FIG. 4 , the optical display device may include a display panel 200 , a polarizing plate 100 disposed above the display panel 200 , and an image sensor 300 disposed below the display panel 200 . have.

The display panel 200 may include a base layer and a plurality of light emitting devices. The display panel 200 is not penetrated for insertion of the image sensor 300 .

The polarizing plate 100 includes a first region 110 and a second region 120 , and includes the polarizing plate of the present invention. Both the first area 110 and the second area 120 form an image display area of the optical display device. The polarizing plate 100 is not penetrated for insertion of the image sensor 300 .

In the first region 110 , the light emitting device is formed less densely than in the second region 120 . Through this, an image display function by the image sensor 300 is also implemented, and an image display function by the display panel 200 can be simultaneously performed.

The image sensor 300 is disposed under the first region 110 . The image sensor 300 may include, but is not limited to, a camera.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, these are presented as preferred examples of the present invention and cannot be construed as limiting the present invention in any sense.

Specific specifications of the components used in the following Examples and Comparative Examples are as follows.

(1) Material of polarizer: polyvinyl alcohol-based film (VF-PE3000, Kuraray, Japan, thickness: 30㎛)

(2) Protective film: triacetyl cellulose film (KC4UYW, Konica, Japan, thickness 40㎛)

Example 1

The polyvinyl alcohol-based film washed with water was subjected to swelling treatment in a water swelling tank at 30°C.

The polyvinyl alcohol-based film passed through the swelling tank was treated for 30 seconds to 200 seconds in a dyeing tank at 30° C. containing an aqueous solution containing 3% by weight of potassium iodide. The polyvinyl alcohol-based film passed through the dyeing tank was passed through a wet crosslinking tank containing 3 wt% of boric acid at 30°C to 60°C. The polyvinyl alcohol-based film passed through the crosslinking tank was stretched in an aqueous solution at 50° C. to 60° C. containing 3 wt% of boric acid, and stretched so that the total draw ratio was 6 times, thereby preparing a dyed and stretched polyvinyl alcohol-based film.

Using a Xenon Flash Lamp, only a portion of the polyvinyl alcohol-based film was irradiated with pulsed light from a Xenon Flash Lamp having a wavelength of 200 nm to 800 nm once under the conditions shown in Table 1 below. A region irradiated with pulsed light by the Xenon Flash Lamp becomes a first polarizer region among polarizers, and a region not irradiated with pulsed light by the Xenon Flash Lamp becomes a second polarizer region among polarizers.

A polarizer was manufactured by depositing or coating a material including an organic black dye such as carbon black or an organic black pigment on the upper surface of the first polarizer region to form a first layer. A first layer was formed in contact with the first polarizer region.

A polarizing plate was prepared by attaching protective films to both sides of the polarizer using an adhesive (Z-200, Nippon Goshei), respectively. A portion of the polarizing plate in which the first layer is formed becomes a first region, and a portion of the polarizing plate in which the first layer is not formed becomes a second region.

Examples 2 to 3

In Example 1, the same method as in Example 1 was carried out, except that the irradiation conditions of pulsed light by the Xenon Flash Lamp were changed as shown in Table 1 below or the method of forming the first layer was changed. A polarizing plate in which the second region was formed was manufactured.

Example 4

A polarizing plate was manufactured in the same manner as in Example 1, except that in Example 1, pulsed light was irradiated by a Xenon Flash Lamp and immersed in lukewarm water at 50° C. for 3 minutes.

Comparative Example 1

In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that the first layer was not formed in the first polarizer region.

The following physical properties were evaluated for the polarizing plates prepared in Examples and Comparative Examples, and the results are shown in Table 1 below.

(1) Polarization degree of the first region and the second region: a wavelength of 200 nm to 800 nm using a UV-Visible Spectrophotometer V730 (JASCO) for each of the first region and the second region among the polarizing plates manufactured in Examples and Comparative Examples The degree of polarization was measured in

(2) Single transmittance (unit: %) of the first region, the second region, the first polarizer region, and the second polarizer region UV- The single transmittance was measured at a wavelength of 200 nm to 800 nm using a Visible Spectrophotometer V730 (JASCO).

A polarizer was manufactured in substantially the same manner as in Examples and Comparative Examples, and single transmittance was measured in the same manner as above for the first polarizer region and the second polarizer region among the polarizers.

(3) Degree of uniformity of color of photos or images according to camera shooting direction: The polarizing plates prepared in Examples and Comparative Examples were used as a viewer-side polarizing plate and mounted on a display panel. When the major axis direction of the display is 90° and the minor axis direction is 0°, the sunglasses effect was evaluated before and after the long axis direction of the display panel was rotated by 90° and 90° respectively. The sunglasses effect means the difference in quality depending on the angle of the camera. When no color difference of the image occurs before and after 90° rotation, it was evaluated as ○, and when color distortion occurred, it was evaluated as X.

(4) Difference in screen quality between the first area in which the image sensor is disposed and the second area in which the image sensor is not disposed: The polarizing plate manufactured in Examples and Comparative Examples was used as a viewer-side polarizing plate and mounted on a display panel. The brightness, pixel resolution, color, etc. of the images in each of the first and second regions were compared by checking the images with a microscope. If there was little difference by area, it was evaluated as ○, if it was slightly recognized, △, and if there was a clear difference, it was evaluated as X.

(5) Reliability: The polarizing plates prepared in Examples and Comparative Examples were left at 60° C. and 95% relative humidity for 500 hours. Then, the degree of change was evaluated by measuring the light transmittance before and after leaving the first area using a light transmittance measuring device UV-Visible Spectrophotometer V730 (JASCO). When the change range was 5% or less, it was evaluated as ○, when it was more than 5% and less than 30%, △, when it was more than 30% and less than or equal to 60%, and when it was more than 60%, it was evaluated as ΔΔ.

Example comparative example One 2 3 4 One Energy Power (V) 500 300 300 500 500 Irradiation time (ms) 15 15 5 15 15 1st floor included? include include include include not included Polarization degree 1st area 5% 10% 15% 2% 5% 2nd area 99% 99% 99% 99% 99% group transmittance 1st area 43% 43% 43% 43% 99% 2nd area 43% 43% 43% 43% 43% group transmittance first polarizer region 90% 85% 80% 90% 90% second polarizer region 44% 44% 44% 44% 44% Degree of color uniformity according to the shooting direction ○ ○ ○ ○ X difference in screen quality ○ △ △ ○ X reliability △ △ △ ○ X

As shown in Table 1, the polarizing plate of the present invention can make the color or sharpness of a photo or image substantially the same regardless of the shooting direction, and the color or sharpness of the screen is substantially the same depending on the viewing direction when viewed with polarized sunglasses. The difference in screen quality between the first area where the image sensor is disposed and the second area where the image sensor is not disposed was minimized, and reliability was excellent.

On the other hand, the polarizing plate of the comparative example not having the first layer could not obtain the effect of the present invention.

Simple modifications or changes of the present invention can be easily carried out by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (13)

A first area and a second area included in the image display area, the first area comprising a first layer,
The first region has a polarization degree of more than 0% and 30% or less and a single transmittance of 20% to 90%,
The difference in the transmittance of a single unit between the first region and the second region is 10% or less, the polarizing plate.
The polarizing plate according to claim 1, wherein the second region has a polarization degree of 80% or more.
The polarizing plate of claim 1 , wherein the polarizing plate includes a polarizer including a first polarizer region corresponding to the first region, a second polarizer region corresponding to the second region, and the first layer.
The polarizing plate of claim 3, wherein the first layer is laminated on at least one surface of the first polarizer region.
The polarizing plate of claim 3, wherein the first polarizer region comprises a polyvinyl alcohol-based film.
The polarizing plate of claim 5 , wherein the first layer has a lower single transmittance compared to the first polarizer region.
The polarizing plate according to claim 5, wherein the first polarizer region and the laminate of the first layer have a polarization degree of more than 0% and 30% or less, and a single transmittance of 20% to 90%.
The polarizing plate according to claim 5, wherein the thickness of the first layer is 1% to 20% of the thickness of the first polarizer region.
The polarizing plate of claim 1 , wherein the first layer includes an organic layer, an inorganic layer, or an organic/inorganic mixed layer.
The polarizing plate of claim 1 , wherein the first layer includes at least one of a dye and a pigment.
The polarizing plate according to claim 3, wherein a protective layer is further formed on at least one surface of the polarizer.
An optical display device comprising the polarizing plate of any one of claims 1 to 11.
The optical display device of claim 12 , wherein the optical display device comprises a display panel, the polarizing plate formed on the upper portion of the display panel, and an image sensor formed on the lower portion of the display panel, wherein the image sensor is located below the first region of the polarizing plate. which is disposed on, an optical display device.

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