JP5509025B2 - Optical filter for display device and display device having the same - Google Patents

Description

  The present invention relates to an optical filter for a display device and a display device including the same, and more particularly to an optical filter for a display device having a color shift reduction pattern and a display device including the same.

  As the information society progresses, image display-related parts and devices have been remarkably advanced and popularized. Among them, display devices that display images have been remarkably widespread for use in televisions, monitors for personal computers, and the like, and are becoming larger and thinner at the same time.

2. Description of the Related Art Generally, a liquid crystal display (Liquid Crystal Display) is one of flat display devices that display images using liquid crystal (Liquid Crystal), and is thinner and lighter than other display devices, and has low driving. It has the advantage of having voltage and low power consumption. For this reason, it is widely used throughout the industry.

FIG. 1 is a conceptual diagram conceptually showing the basic structure and driving principle of the LCD 100.
Taking a conventional VA mode LCD as an example, the two polarizing films 110 and 120 are attached such that their optical axes are perpendicular to each other. Between the two transparent substrates 130 coated with the transparent electrode 140, liquid crystal molecules 150 exhibiting birefringence characteristics are inserted and arranged. When an electric field is applied by the driving power supply unit 180, liquid crystal molecules move and are aligned perpendicular to the electric field.
The light emitted from the backlight unit becomes linearly polarized light after passing through the first polarizing film 120.

  As shown on the left side of FIG. 1, when the power is off, the liquid crystal is aligned perpendicular to the substrate. For this reason, the liquid crystal cannot change the polarization state of light. As a result, the linearly polarized light is maintained as it is and cannot pass through the second polarizing film 110 whose optical axis is perpendicular to the first polarizing film 120.

  On the other hand, as shown in the right side of FIG. 1, when the power is on, the liquid crystal is placed between the optical axes of two orthogonal polarizing films 110 and 120 along the direction parallel to the substrate by the electric field. Oriented horizontally. Therefore, linearly polarized light or circularly polarized light whose polarization state is rotated by 90 ° immediately before reaching the second polarizing film while the light linearly polarized through the first polarizing film passes through the liquid crystal molecules. Or it changes to an elliptically polarized state and comes to pass through the second polarizing film. By adjusting the strength of the electric field, the alignment angle of the liquid crystal is gradually changed from the vertical alignment to the horizontal direction, and the intensity of the emitted light can be adjusted.

FIG. 2 is a conceptual diagram showing the alignment state and light transmittance of the liquid crystal depending on the viewing angle.
When the liquid crystal molecules are arranged in a predetermined direction in the pixel 220, the arrangement state looks different depending on the viewing angle.
When viewed in the right direction 210 from the front, the alignment state of the liquid crystal molecules looks almost horizontal alignment 212, and the screen looks relatively bright. When viewed from the front surface 230 of the screen, the alignment state 232 of the liquid crystal molecules looks the same as the alignment of the liquid crystal molecules in the pixel 220. When viewed in the left direction 250 from the front, the alignment state of the liquid crystal molecules looks like a vertical alignment 252 and the screen looks relatively dark.

  Therefore, in the LCD, a change in light intensity or color occurs with a change in viewing angle, and the viewing angle is greatly limited as compared with a self-luminous display. For this reason, many studies for improving the viewing angle have been conducted.

FIG. 3 is a conceptual diagram illustrating an example of a conventional technique for improving the change in the light-to-dark ratio and the color shift depending on the viewing angle.
Referring to FIG. 3, the pixel is divided into two partial pixels, that is, a first pixel unit 320 and a second pixel unit 340 so that the liquid crystal alignment states of the pixel units are symmetrical to each other. Depending on the viewing direction of the viewer, the arrangement state of the liquid crystal in the first pixel unit 320 and the arrangement state of the liquid crystal in the second pixel unit 340 can be seen at the same time. , The sum of the light intensity of each pixel portion.

  That is, when viewed from the front in the right direction 310, the liquid crystal of the first pixel unit 320 appears in the horizontal alignment 312 and the liquid crystal of the second pixel unit 340 appears in the vertical alignment 314, so that the first pixel unit 320 makes the screen appear brighter. Similarly, when viewed from the front in the left direction 350, the liquid crystal of the first pixel portion 320 appears as a vertical alignment 352, and the liquid crystal of the second pixel portion 340 appears as a horizontal alignment 354, whereby the second pixel Part 340 makes the screen appear brighter. When viewed from the front 330, it looks the same as the arrangement state of each pixel portion.

  For this reason, the brightness of the screen as viewed by the viewer is the same or substantially the same as the viewing angle changes, and is symmetric about the vertical direction with respect to the screen. Thereby, the change of the light / dark ratio and the degree of color change accompanying the change of the viewing angle can be improved.

FIG. 4 is a conceptual diagram showing another example of the prior art for improving the change in light-to-dark ratio and the color shift depending on the viewing angle.
Referring to FIG. 4, an optical film 420 having birefringence characteristics, the same characteristics as the liquid crystal molecules in the pixel 440 of the LCD panel, and symmetric with the arrangement state of the liquid crystal molecules is further provided. . The intensity of light visible to the viewer is the sum of the intensity of the light depending on the alignment state of the liquid crystal in the pixel 440 according to the viewing direction of the viewer and the birefringence characteristics of the optical film 420.

That is, when viewed from the front in the right direction 410, the liquid crystal in the pixel 440 appears as a horizontal alignment 414, the virtual liquid crystal formed by the optical film 420 appears as a vertical alignment 412, and the light intensity is the sum of the respective. Become. Similarly, when viewed in the left direction 450 from the front, the liquid crystal in the pixel 440 appears as a vertical alignment 454, the virtual liquid crystal formed by the optical film 420 appears as a horizontal alignment 452, and the intensity of light is the sum of the respective values. become. When viewed from the front 430, the arrangement state of the liquid crystal molecules in the pixel 440 and the birefringence arrangement state of the optical film 420 appear to be the same (432, 434).
However, the techniques shown in FIGS. 3 and 4 still have a problem that a color shift due to a viewing angle still exists and a color change occurs as the viewing angle increases.

An object of the present invention is to provide an optical filter capable of improving a color shift phenomenon accompanying an increase in viewing angle, and a display device including the same.
Another object of the present invention is to provide an optical filter capable of improving transmittance and a display device including the same.
Another object of the present invention is to provide an optical filter capable of preventing a hue from the front of a display image from being changed by a color light absorbing material, and a display device including the same.
The technical problems to be solved by the present invention are not limited to the technical problems described above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following.

  In order to achieve the above object, the present invention provides an optical filter for a display device, a background layer forming a layer, a color shift reduction pattern formed on the background layer with a predetermined thickness, and the above There is provided an optical filter for a display device, comprising a light reflection patch formed behind a color shift reduction pattern and reflecting light backward.

  The color shift reduction pattern may include one of a color light absorbing material and a light diffusing material.

  The color light absorbing material may include a green wavelength absorbing material that absorbs a green wavelength of 510 to 560 nm. The color light absorbing material may further include a cyan wavelength absorbing material that absorbs a cyan wavelength of 480 to 510 nm and an orange wavelength absorbing material that absorbs an orange wavelength of 570 to 600 nm. The color light absorbing material may further contain a black material.

  The light diffusing material may include light diffusing beads.

  The color shift reduction pattern may have a plurality of divided regions, and at least one of the plurality of divided regions may be different from each other in at least one of a light absorption rate and a light diffusion rate.

  The first divided region may be formed in front of or behind the second divided region, or may be formed apart from each other.

According to the present invention having the above-described configuration, there is an effect that it is possible to provide an optical filter that can improve a color shift phenomenon accompanying an increase in viewing angle and a display device including the same.
In addition, an optical filter capable of improving the transmittance and a display device including the same can be provided.
Furthermore, there is an effect that it is possible to provide an optical filter that can prevent the hue from the front of the display image from being changed by the color light absorbing material, and a display device including the optical filter.

It is a conceptual diagram which shows notionally the basic structure and drive principle of LCD. It is a conceptual diagram which shows the orientation state and light transmittance of the liquid crystal by a viewing angle. It is a conceptual diagram which shows an example of the prior art for improving the change of the light-dark ratio by a viewing angle, and a color shift. It is a conceptual diagram which shows another example of the prior art for improving the change of the light / dark ratio by a viewing angle, and a color shift. It is a graph which shows the color shift by the viewing angle of LCD in the state which is not mounting | wearing with the optical filter of this invention. It is sectional drawing which shows the optical filter by the comparative embodiment of this invention. It is a reference figure for demonstrating a color light absorption substance. It is a reference figure for demonstrating a color light absorption substance. It is a graph which shows the color shift of LCD with which the optical filter of FIG. 6 was mounted | worn. It is sectional drawing which shows the optical filter by the 1st Embodiment of this invention. It is a reference diagram for explaining a cyan wavelength absorbing material and an orange wavelength absorbing material. It is a reference diagram for explaining a cyan wavelength absorbing material and an orange wavelength absorbing material. It is a reference figure for demonstrating a black substance. It is a reference figure for demonstrating a black substance. It is sectional drawing which shows the optical filter by the 2nd Embodiment of this invention. It is sectional drawing which shows the optical filter by the 3rd Embodiment of this invention. It is sectional drawing which shows the optical filter by the 4th Embodiment of this invention. It is sectional drawing which shows the optical filter by the 5th Embodiment of this invention. It is sectional drawing which shows the optical filter by the 6th Embodiment of this invention. It is sectional drawing which shows the optical filter by the 7th Embodiment of this invention. It is sectional drawing which shows the optical filter by the 8th Embodiment of this invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[Comparative embodiment]
FIG. 6 is a perspective view showing an optical filter according to a comparative embodiment of the present invention. As shown in the figure, the optical filter of FIG. 6 includes a background layer 10 and a color shift reduction pattern 20.
The color shift reduction pattern 20 includes a color light absorbing material. The color light absorbing material includes a green wavelength absorbing material that absorbs a green wavelength of 510 to 560 nm. The color light absorbing material may further include a cyan wavelength absorbing material that absorbs a cyan wavelength of 480 to 510 nm and an orange wavelength absorbing material that absorbs an orange wavelength of 570 to 600 nm. In addition, the color light absorbing material may further include a black material such as carbon black. The background layer 10 or the backing layer 30 includes a complementary color material that reduces or adjusts the amount of red (R), green (G), and blue (G) to change or adjust the color balance. May be included.

  When the light emitted from the front of the display passes through the optical filter for the display device, the image color of the display changes due to the color shift reduction pattern. Therefore, the background layer 10 or the backing layer 30 absorbs a wavelength region other than the green wavelength region, the orange wavelength region, and the cyan wavelength region with a complementary color pigment, such as a red wavelength absorbing material or a blue wavelength absorbing material. By appropriately including a green complementary color wavelength absorbing substance, the original color can be complemented near the front. Accordingly, since the background layer 10 or the backing layer 30 is formed by further including a complementary color material without being provided as a separate layer or film, the structure of the optical filter can be simplified and the manufacturing process can be shortened. It becomes possible to become. Of course, the complementary color substance may be contained in the adhesive layer in addition to the background layer 10 or the backing layer 30, and may be contained in another functional film.

7 and 8 are reference views for explaining the color light absorbing material.
An optical filter in which the color shift reducing pattern 20 is filled with a green wavelength absorbing material or the like is mounted on an LCD TV, and the color coordinates at the front angle and the viewing angle of 60 ° in a full white screen are compared.

  When the wedge-shaped cross-section color shift reduction pattern 20 is filled with a green wavelength absorbing material, the hue of the green wavelength absorbing material appears strongly as the viewing angle increases, and the CIE 1976 UCS color coordinate system u′v ′ is close to the pink region. The color coordinate moves to. In addition, when i) carbon black or ii) cyan wavelength absorption material and orange wavelength absorption material is filled together with the green wavelength absorption material, the color coordinates close to the purple pink region in the color coordinate meter u′v ′. Move.

In the color coordinate meter u′v ′, Δv ′ / Δu ′, that is, the value of (v′60−v′0) / (u′60−u′0) is tan (−15 °) to tan (45 °). (Where u′0 and v′0 are color coordinate values measured at a viewing angle of 0 °, and u′60 and v′60 are color coordinates measured at a viewing angle of 60 °). Value).
Specifically, when the color shift reducing pattern 20 is filled with only the green wavelength absorbing material, the color coordinate change gradient at the viewing angle of 60 ° with respect to the front surface in the color coordinate meter u′v ′ is 15 °. It is preferably ˜45 °. When the green wavelength absorbing material and carbon black are filled together, the gradient of the change in color coordinates at a viewing angle of 60 ° with respect to the front surface is preferably -15 ° to 15 °. When the green wavelength absorbing material, the cyan wavelength absorbing material, and the orange wavelength absorbing material are filled together, it is preferable that the gradient of the change in color coordinates at a viewing angle of 60 ° with respect to the front surface is −15 ° to 15 °.

FIG. 9 is a diagram showing color shifts of 13 kinds of mixed colors according to a change in viewing angle in an LCD TV equipped with the optical filter of FIG.
An optical filter was prepared by filling the color shift reduction pattern 20 of FIG. 6 with 0.5 wt% of a green wavelength absorbing material (pink dye), and then a color shift result as shown in FIG. 9 was obtained.

Embodiment of the present invention
FIG. 10 is a cross-sectional view showing the optical filter according to the first embodiment of the present invention.
The optical filter of the present invention is typically provided in front of the display panel of the display device, but may be provided between the display panel and the backlight unit.
The optical filter includes a background layer 10, a color shift reduction pattern 20, and a light reflection patch 40. The background layer 10 is formed by layering a material that transmits light. The background layer 10 may be made of an ultraviolet curable resin.

  The color shift reduction pattern 20 is formed on the background layer 10 with a predetermined thickness. Color shift reduction pattern is wedge-shaped cross-section stripe pattern, wedge-shaped cross-section wave pattern, wedge-shaped cross-section matrix pattern, wedge-shaped cross-section honeycomb pattern, quadrilateral cross-section stripe pattern, quadrilateral cross-section wave pattern, quadrilateral cross-section matrix pattern, and quadrilateral cross-section honeycomb pattern Any of these may be used.

  For example, even in the case of a stripe pattern, various patterns such as a horizontal stripe pattern and a vertical stripe pattern can be provided. When formed in the horizontal direction, it is effective for vertical viewing angle compensation, and when formed in the vertical direction, it is effective for horizontal viewing angle compensation.

In addition, the moire phenomenon can be efficiently prevented by arranging with a predetermined bias angle with respect to the horizontal direction or the vertical direction.
The color shift reduction pattern may be formed so that the bottom surface thereof faces the viewer or may be formed so as to face the display panel. It can also be formed on both sides of the background layer 10.

Although FIG. 10 illustrates an embodiment in which the color shift reduction pattern is embedded in the background layer 10, the embodiment is not necessarily limited thereto, and may be formed to protrude.
The color shift reduction pattern includes at least one of a color light absorbing material and a light diffusing material. The color light absorbing material includes i) a green wavelength absorbing material, ii) a cyan wavelength absorbing material and an orange wavelength absorbing material together with the green wavelength absorbing material, iii) a green wavelength absorbing material, a cyan wavelength absorbing material, and an orange wavelength absorbing material. The material may include a black material such as carbon black, or iv) a black material such as carbon black may be included together with the green wavelength absorbing material.

[Color shift reduction pattern including green wavelength absorbing material]
In general, in the display industry, 13 types of color mixture (White, Red, Blue, Green, Skin, Sony Red, Sony Blue, Sony Green, Cyan, Purple, Yellow, Moderate Red, Purple Blue) are generally used as evaluation criteria for display devices. evaluate.

  When the white light emitted from the display panel has a high gradation, as the viewing angle increases, the luminance in the entire wavelength region decreases, while it decreases relatively quickly in the blue wavelength region, When it has a low gradation, the luminance in the entire wavelength region increases as the viewing angle increases, and increases relatively fast in the green wavelength region.

  Accordingly, the green wavelength absorbing material is filled in the color shift reduction pattern so that the absorption in the entire wavelength region of the light emitted from the display panel gradually increases as the viewing angle increases, and in particular, the green wavelength of 510 to 560 nm. By making the absorption of light in the wavelength region relatively large, the difference in RGB relative luminance due to the change in the viewing angle and gray level, which is the cause of the color shift, is reduced, and as the viewing angle increases Color shift can be minimized.

  As the green wavelength absorbing substance, either an inorganic substance or an organic substance that can absorb light having a green wavelength of 510 to 560 nm may be used, and a pink pigment is preferably used. The green wavelength absorbing substance is not particularly limited as long as it can absorb light having a green wavelength in addition to the pink pigment.

[Color shift reduction pattern including green wavelength absorbing material + cyan wavelength absorbing material + orange wavelength absorbing material]
FIG. 11 is a graph showing emission spectra of the LED and the CCFL backlight.
As shown in FIG. 11, unlike LEDs (shown on the left side of FIG. 11), CCFL backlights (shown on the right side of FIG. 11) have strong peaks in the cyan wavelength region near 490 nm and the orange wavelength region near 590 nm. To do.
Such peaks in the cyan and orange wavelength regions reduce the color reproduction area and cause the color shift to deteriorate.

FIG. 12 is a diagram showing a color shift due to a change in the viewing angle of the LED and the CCFL backlight.
As shown in FIG. 12, the color shift result of the LCD composed of the LED (shown on the left side of FIG. 12) and the backlight of the CCFL (shown on the right side of FIG. 12) shows that the CCFL is worse. . Therefore, if the peaks in the cyan wavelength region and the orange wavelength region, which adversely affect the color shift due to the change in the viewing angle, can be absorbed more as the viewing angle increases, the color of the mixed color as the viewing angle increases. Changes can be further minimized.

  In order to play such a role, the color shift reduction pattern includes not only a green wavelength absorbing material that absorbs a green wavelength region of 510 to 560 nm, but also a cyan wavelength absorbing material of 480 to 510 nm, and an orange wavelength absorption of 570 to 600 nm. Substances may be included. As a result, the green wavelength region in the light emitted from the display panel absorbs more as the viewing angle increases, and the cyan wavelength region and orange wavelength adversely affect the color shift due to the change in viewing angle in the LCD spectrum. The region peaks absorb more with increasing viewing angle. Thereby, the color change accompanying the increase in the viewing angle is minimized, and the color change in all the mixed colors including the blue mixed color system and the red mixed color system is minimized, so that the effect of improving the viewing angle can be further increased.

[Color shift reduction pattern including black material]
The color shift can be improved by further including a black material such as carbon black in the color shift reduction pattern.
13 and 14 are diagrams showing changes in luminance and normalized luminance depending on the viewing angle and gray level of the Bare LCD.

  As the viewing angle increases at a high gray level, the luminance decreases. However, at a low gray level, the luminance increases as the viewing angle increases. Such a phenomenon causes the color shift to deteriorate. As a result, as the viewing angle increases, more light can be absorbed from the display panel, and regardless of the gray level, even if the viewing angle increases, the brightness decreases. Can be improved.

  The light reflection patch 40 is provided behind the color shift reduction pattern and reflects light backward. As shown in FIG. 15, the light reflecting patch reflects light incident on the color shift reduction pattern in the light emitted from the display panel, and the reflected light is reflected again by the display panel or the tempered glass and forwards. It is possible to improve the transmittance.

  In addition, since the light incident on the color shift reduction pattern filled with the color light absorbing material is reflected, it is possible to prevent the display image color from being changed by the color light absorbing material. In order to compensate for the color change in the front due to the color light absorbing material, a material that transmits only the absorption wavelength of the color light absorbing material is included in the background layer, backing layer, or the like, or only the absorption wavelength of the color light absorbing material is transmitted. Since it is not necessary to form a separate layer containing a substance, the transmittance can be further improved.

The light reflecting patch 40 can be formed by filling metal particles. For example, it can be formed by filling a mixture (Ag Paste) of Ag particles and resin.
In addition, the optical filter may include a backing layer 30 that supports the background layer 10 as shown in FIG. In some embodiments, the backing layer can be omitted.

  The backing layer 30 is preferably a transparent resin film having ultraviolet transparency. As a material for the backing layer 30, for example, polyethylene terephthalate (PET), polycarbonate (PC), polyvinyl chloride (PVC), or the like may be used.

  FIG. 15 is a cross-sectional view schematically showing an optical filter according to the second embodiment of the present invention. As shown in the figure, the optical filter of the present invention can include a tempered glass transparent substrate 50.

FIG. 16 is a cross-sectional view schematically showing an optical filter according to the third embodiment of the present invention. As shown in the figure, the color shift reduction pattern may include a light diffusing material.
As the viewing angle increases, the light diffusing material diffuses more light uniformly from the display panel, thereby inducing color mixing and improving color shift. As the light diffusing material, light diffusing particles such as light diffusing beads may be used.

  Typically, the color light absorbing material and the light diffusing material are included in the color shift reduction pattern mixed with the transparent polymer resin, but the refractive index of the light diffusing particles is larger than the refractive index of the polymer resin. In order to obtain an excellent light diffusion effect, it is more preferably at least 0.01 or more.

The light diffusing particles are preferably white that can diffuse light of all wavelengths with particles having an average particle diameter of 0.1 μm or more. Note that the present invention is not limited to this.
The light diffusing particles may have two or more sizes and refractive indexes, and suitable optical characteristics can be controlled using the material, refractive index, size, particle size distribution, and the like of the light diffusing particles. The light diffusing particles are at least one of PMMA, vinyl chloride, acrylic resin, PC-based, PET-based, PE-based, PS-based, PP-based, PI-based resin, glass and oxides such as silica (TiO2). Can be included.

17 and 18 are cross-sectional views schematically showing optical filters according to the fourth and fifth embodiments of the present invention, respectively.
The color shift reduction pattern can have a plurality of divided regions. Here, at least two regions have different light absorption and / or light diffusivity.

  For this, the at least two regions may include different color light absorbing materials and / or light diffusing materials. For example, the first divided region 21 and the second divided region 23 may include different types of color light absorbing materials so that the light absorption rate is different.

  As another example, the at least two regions may include a color light absorbing material and / or a light diffusing material in different content ratios. Here, the content ratio includes a case where the content ratio is zero.

  For example, assuming an embodiment in which the color shift reduction pattern has two divided regions, a first divided region 21 and a second divided region 23, i) the first divided region 21 is colored light as shown in FIG. The second divided region 23 includes a light diffusing material, or ii) the first divided region includes both the color light absorbing material and the light diffusing material, and the second divided region includes the color light absorbing material and the light diffusing material. Various modifications are possible, such as including only one of the materials, or iii) both the first divided region and the second divided region include both the color light absorbing material and the light diffusing material.

  Although each divided area can have various arrangements, FIGS. 17 and 18 show an embodiment in which the first divided area 21 is formed in front of or behind the second divided area 23. . The optical filter of FIG. 17 is formed by performing the following steps.

  First, after an ultraviolet curable resin is applied to one side of the backing layer 30, a groove is formed in the ultraviolet curable resin using a pattern forming roll. Thereafter, the ultraviolet curable resin is irradiated with ultraviolet rays, and finally, the background layer 10 in which the wedge-shaped cross-sectional grooves are formed is completed. Note that the present invention is not limited to this, and various methods such as a hot pressing method using a thermoplastic resin and an injection molding method in which a thermoplastic resin or a thermosetting resin is filled and molded are used. A groove in the background layer can be obtained.

  After that, the groove is filled with a mixture of a color light absorbing material, an ultraviolet curable polymer resin, a solvent, and the like, and then the solvent is evaporated by drying. Irradiate to cure.

  Thereafter, the groove is again filled with a mixture of a light diffusing substance, an ultraviolet curable polymer resin, and the like, and then irradiated with ultraviolet rays to complete a color shift reduction pattern. At this time, the filling amount of the mixture needs to be determined in consideration of the fact that the light reflecting material is filled in the concave grooves in the subsequent process.

Next, the groove is filled again with, for example, a mixture of a light reflecting material and a resin, and then cured to complete a light reflecting patch.
FIG. 19 is a cross-sectional view schematically showing an optical filter according to the sixth embodiment of the present invention. As shown in the figure, the plurality of divided regions may be formed apart from each other on a vertical plane perpendicular to the optical filter. The plurality of divided regions can have various arrangements, and may have a regular arrangement order. FIG. 19 shows an embodiment in which the first divided areas and the second divided areas are alternately arranged.

The optical filter of FIG. 19 can be manufactured by performing the following steps.
First, after an ultraviolet curable resin is applied to one side of the backing layer 30, a groove is formed in the ultraviolet curable resin using a pattern forming roll. Thereafter, the ultraviolet curable resin is irradiated with ultraviolet rays to finally complete the background layer 10 in which the wedge-shaped cross-sectional grooves are formed.

  Note that the present invention is not limited to this, and various methods such as a hot pressing method using a thermoplastic resin and an injection molding method in which a thermoplastic resin or a thermosetting resin is filled and molded are used. A groove in the background layer can be obtained.

After that, the groove is filled with a mixture of a light absorbing material forming the first divided region (or a light diffusing material forming the second divided region), an ultraviolet curable resin, etc., and then irradiated with ultraviolet rays. Harden.
Then, a ditch | groove is formed with a laser.
Thereafter, the concave groove is filled with a mixture of a light diffusing material forming the second divided region (or a light absorbing material forming the first divided region), an ultraviolet curable resin, or the like. At this time, the filling amount of the mixture needs to be determined in consideration of the fact that the light reflecting material is filled in the concave grooves in the subsequent process.

Next, the UV shift resin is cured by irradiating ultraviolet rays, thereby completing the color shift reduction pattern.
Next, the groove is filled again with, for example, a mixture of a light reflecting material and a resin, and then cured to complete the light reflecting patch 40.

20 and 21 are cross-sectional views schematically showing optical filters according to the seventh and eighth embodiments of the present invention, respectively.
As shown in the figure, the arrangement of the first divided region 21 and the second divided region 23 can have various modifications. FIG. 20 shows an embodiment in which the arrangement is a regular arrangement order in which two first divided areas and one second divided area are repeated in this order, and FIG. 21 shows the second divided area 2. In addition, an embodiment is shown in which the arrangement is in a regular order, i.e., repetition in the order of one first divided region.

  In addition, the first divided region and the second divided region may be arranged so as to be symmetrical with respect to the center of the optical filter. For example, the first divided area on each of the left and right sides from the center is arranged in the first divided area, and the second to fourth divided areas on the left and right are arranged in the second divided area. Is possible.

10 and 15 to 21 exemplify embodiments in which the color shift reduction pattern is composed of two divided regions for convenience of explanation, the present invention is not limited to this and may have three or more divided regions. Needless to say, you can.
The optical filter for a display device of the present invention is formed by laminating various functional films such as an antireflection layer, an antiglare layer, and an antifog layer in addition to the background layer, backing layer, and tempered glass transparent substrate.

  As described above, for convenience of explanation, the present invention has been described by taking the LCD as an example of the display device, but the display device of the present invention is not necessarily limited thereto. The display device of the present invention is variously used for large display devices such as PDP, OLED, FED, etc. that implement RGB, small mobile display devices such as PDAs, display windows for small game machines, display windows for mobile phones, and flexible display devices. Applicable.

DESCRIPTION OF SYMBOLS 10 Background layer 20 Color shift reduction pattern 21 1st division area 23 2nd division area 30 Backing layer 40 Light reflection patch 50 Tempered glass transparent substrate

Claims (12)

An optical filter for a display device,
A layered background layer,
A color shift reduction pattern formed at a predetermined thickness on the background layer;
A light reflection patch that is formed behind the color shift reduction pattern and reflects light backward,
The color shift reduction pattern includes at least a light diffusing material among a color light absorbing material and a light diffusing material,
The optical filter for a display device, wherein the light diffusing material includes light diffusing beads.   The optical filter for a display apparatus according to claim 1, wherein the color light absorbing material includes a green wavelength absorbing material that absorbs a green wavelength of 510 to 560 nm.   The display apparatus according to claim 2, wherein the color light absorbing material further includes a cyan wavelength absorbing material that absorbs a cyan wavelength of 480 to 510 nm and an orange wavelength absorbing material that absorbs an orange wavelength of 570 to 600 nm. Optical filter.   The optical filter for a display apparatus according to claim 2, wherein the color light absorbing material further includes a black material.   The optical filter for a display device according to claim 4, wherein the black material is carbon black.   The optical filter for a display device according to claim 1, wherein the color shift reduction pattern includes a resin.   The color shift reduction pattern includes a wedge-shaped cross-section stripe pattern, a wedge-shaped cross-section wave pattern, a wedge-shaped cross-section matrix pattern, a wedge-shaped cross-section honeycomb pattern, a quadrilateral cross-section stripe pattern, a quadrilateral cross-section wave pattern, a quadrilateral cross-section matrix pattern, and a quadrilateral cross-section honeycomb. The optical filter for a display device according to claim 1, wherein the optical filter is a pattern. The color shift reduction pattern has a plurality of divided regions,
2. The optical filter for a display device according to claim 1, wherein at least one of the plurality of divided regions is different from each other in at least one of a light absorption rate and a light diffusion rate. The color shift-reducing pattern includes a color light absorbing material and the light diffusing material quality,
The color shift reduction pattern has two divided areas, a first divided area and a second divided area,
9. The optical filter for a display device according to claim 8, wherein the color light absorbing material is included only in the first divided region, and the light diffusing material is included only in the second divided region.   The optical filter for a display device according to claim 9, wherein the first divided region is formed in front of or behind the second divided region.   The optical filter for a display device according to claim 9, wherein the first divided region and the second divided region are formed to be separated from each other.   A display device comprising the optical filter for a display device according to claim 1.