Optical film and display device including the same

Abstract

The invention provides an optical film and a display device including the same. The optical film includes: a first optical layer having a concave pattern formed in an upper portion of the first optical layer; a second optical layer disposed on the first optical layer and configured to convert light in a first wavelength band among the light transmitted through the first optical layer into light in a second wavelength band larger than the first wavelength band; and a third optical layer disposed on the second optical layer and configured to transmit light having a wavelength greater than or equal to a predetermined wavelength among the light transmitted through the second optical layer and to reflect light having a wavelength less than the predetermined wavelength toward the first optical layer.

Description

Technical Field

[0001] The present disclosure relates to an electronic device having a display, and more particularly, to an optical film and a display device including the optical film, the optical film having a structure configured to block blue light from a light source, thereby providing an advantage of minimizing retinal function decline or eye fatigue. Background Art

[0002] Blue light refers to light having a wavelength in the range of 380 nm to 500 nm in visible light. This blue light has the shortest wavelength among visible light visible to the human eye and has strong energy close to ultraviolet light.

[0003] Blue light generally comes from the sun. When the sun is at its highest point, the largest amount of blue light is emitted during the day, and blue light disappears at night. Blue light may have a positive effect on attention, reaction time, and mood during the day, but it may have harmful effects on health at night, such as disrupting the biological rhythm.

[0004] Blue light is also emitted through the liquid crystal display screens of increasingly popular electronic devices such as smartphones, tablets, and computer monitors. In particular, considering the increasing number of users who use such electronic devices even in a dark environment, users of electronic devices are increasingly exposed to blue light not only during the day but also at night.

[0005] The descriptions provided in this discussion of the related art should not be assumed to be prior art merely because they are mentioned in or associated with this discussion of the related art. The discussion of the related art may include information that describes one or more aspects of the subject technology, and the descriptions in this section do not limit the present disclosure. Summary of the Invention

[0006] The inventors of the present application have found that when exposed to blue light for a long time, blue light may cause dry eyes, eye fatigue, vision decline, and retinal function decline, and may cause sleep disorders by disrupting melatonin, which has a negative impact on the human body.

[0007] To solve these problems, one or more aspects of the present disclosure may provide an optical film and a display device including the optical film, the optical film having a structure configured to block blue light from a light source, thereby providing an advantage of minimizing retinal function decline or eye fatigue.

[0008] One or more aspects of the present disclosure may provide an optical film and a display device including the optical film, the optical film having a structure that recycles blue light from a light source inside, thereby being able to improve the efficiency of blocking blue light harmful to the human body.

[0009] One or more aspects of the present disclosure may provide an optical film and a display device including the optical film. The optical film has a structure configured to convert one or more wavelengths of blue light from a light source into one or more higher wavelengths, rather than absorbing and removing blue light having a wavelength in the range of 380 nm to 450 nm, so that one or more desired wavelengths can be blocked without reducing brightness.

[0010] One or more aspects of the present disclosure may provide an optical film and a display device including the optical film. The optical film can be used with lower power consumption using a single material by blocking one or more desired wavelengths without reducing brightness.

[0011] According to one or more exemplary embodiments of the present disclosure, an optical film may be provided. The optical film includes: a first optical layer having a concave pattern formed in an upper portion of the first optical layer; a second optical layer disposed on the first optical layer and configured to convert light in a first band among light transmitted through the first optical layer into light in a second band greater than the first band; and a third optical layer disposed on the second optical layer and configured to transmit light having a wavelength greater than or equal to a predetermined wavelength among light transmitted through the second optical layer and reflect light having a wavelength less than the predetermined wavelength toward the first optical layer.

[0012] According to one or more exemplary embodiments of the present disclosure, a display device may be provided. The display device includes: a backlight unit; a substrate portion disposed on the backlight unit; an optical film disposed on the substrate portion; a liquid crystal layer disposed on the optical film; and a color filter disposed on the liquid crystal layer. The optical film includes: a first optical layer having a concave pattern formed in an upper portion of the first optical layer; a second optical layer disposed on the first optical layer and configured to convert light in a first band among light transmitted through the first optical layer into light in a second band greater than the first band; and a third optical layer disposed on the second optical layer and configured to transmit light having a wavelength greater than or equal to a predetermined wavelength among light transmitted through the second optical layer and reflect light having a wavelength less than the predetermined wavelength toward the first optical layer.

[0013] One or more aspects of the present disclosure may provide an optical film and a display device including the optical film. The optical film has a structure configured to block blue light from a light source, thereby providing the advantage of minimizing retinal function decline or eye fatigue.

[0014] According to one or more aspects of the present disclosure, an optical film and a display device including the optical film can be provided. The optical film has a structure for recycling blue light from a light source inside, so as to be able to improve the efficiency of blocking blue light harmful to the human body.

[0015] According to one or more aspects of the present disclosure, an optical film and a display device including the optical film can be provided. The optical film has a structure configured to convert one or more wavelengths of blue light from a light source into one or more higher wavelengths, rather than absorbing and removing blue light with wavelengths in the range of 380 nm to 450 nm, so as to be able to block one or more desired wavelengths without reducing brightness.

[0016] According to one or more aspects of the present disclosure, an optical film and a display device including the optical film can be provided. The optical film can be used with lower power consumption using a single material by blocking one or more desired wavelengths without reducing brightness.

[0017] The objectives according to the present disclosure are not limited to the above objectives. Other objectives and advantages not mentioned according to the present disclosure can be understood based on the following description, and can be more clearly understood based on the embodiments according to the present disclosure. In addition, it will be readily understood that the objectives and advantages according to the present disclosure can be achieved by using the means shown in the claims or combinations thereof.

[0018] It should be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory, and are intended to provide further explanation of the claimed present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification, illustrate aspects of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. In the drawings:

[0020] Figure 1 An exemplary configuration of an optical film according to aspects of the present disclosure is shown;

[0021] Figure 2 is a diagram showing an example wavelength conversion of light transmitted through Figure 1 the second optical layer shown;

[0022] Figure 3 Schematically shows an example path of light passing through Figure 1 the optical film;

[0023] Figure 4 Shows the configuration of a display device according to an exemplary embodiment of the present disclosure;

[0024] Figure 5 Shows the configuration of the display device according to Comparative Example 1;

[0025] Figure 6 Shows the configuration of the display device according to Comparative Example 2; and

[0026] Figure 7 Is a diagram showing a display device according to an exemplary embodiment of Figure 4 and a comparative example 1 according to Figure 5 and a comparative example 2 according to Figure 6 showing the amount of light with respect to wavelength in the display devices.

[0027] Throughout the drawings and the detailed description, unless otherwise described, the same reference numerals should be understood to refer to the same elements, features, and structures. For clarity, illustration, and convenience, the relative dimensions of these elements and their descriptions may be exaggerated. Detailed Description

[0028] Now, reference will be made in detail to the exemplary embodiments of the present disclosure, examples of which are shown in the drawings. In the following description, unless otherwise specified, the structures, embodiments, implementations, methods, and operations described herein are not limited to the specific examples set forth herein and may be changed as known in the art. Unless otherwise specified, the same reference numerals always represent the same elements. The names of the corresponding elements used in the following explanations are only selected for the convenience of writing the specification and may therefore be different from those used in actual products.

[0029] Advantages and features of the present disclosure and methods for realizing them will be clarified by the exemplary embodiments described below with reference to the drawings. However, the present disclosure may be embodied in different forms and should not be construed as limited to the exemplary embodiments set forth herein. Instead, these exemplary embodiments are provided so that the present disclosure may be thorough and complete and may help those skilled in the art fully understand the scope of the present disclosure. In addition, the scope of protection of the present disclosure is defined by the claims and their equivalents.

[0030] In the following description, detailed descriptions of related known functions or configurations may be omitted where such detailed descriptions may unnecessarily obscure aspects of the present disclosure. The shapes, sizes, ratios, angles, numbers, etc. shown in the drawings for describing various exemplary embodiments of the present disclosure are only given as examples. Therefore, the present disclosure is not limited to the illustrations in the drawings. Terms such as "including", "having", "containing", "constituting", "comprising", and "forming" used herein generally intend to allow the addition of other components, unless these terms are used together with the term "only". As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise.

[0031] In the description of temporal relationships, for example, the temporal precedence relationship between two events, such as "after", "subsequently", and "before", other events may occur between them unless "immediately after", "immediately subsequently", or "immediately before" is indicated.

[0032] Although terms such as "first", "second", "A", "B", "(a)", "(b)" etc. may be used herein to describe various elements, these elements should not be construed as being limited by these terms because they are not used to define a specific order or priority. These terms are only used to distinguish one element from another. For example, without departing from the scope of the present disclosure, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element.

[0033] When referring to a first element being "connected or coupled to", "in contact with or overlapping" a second element, it should be understood that not only can the first element be "directly connected or coupled to" or "directly in contact with or overlapping" the second element, but also a third element may be "interposed" between the first element and the second element, or the first element and the second element may be "connected or coupled to", "in contact with or overlapping" each other via a fourth element, etc. Here, the second element may be included in at least one of two or more elements that are "connected or coupled to", "in contact with or overlapping" each other, etc.

[0034] In the case of describing a positional relationship, for example, when using terms such as "on", "above", "under", "over", "below", "beside", "adjacent to" etc. to describe the positional relationship between two parts, unless more restrictive terms such as "immediately", "directly", or "closely" are used, one or more other parts may be located between the two parts. For example, in the case where one element or layer is disposed "on" another element or layer, a third element or layer may be interposed therebetween. In addition, terms such as "left", "right", "top", "bottom", "down", "up", "upper", "lower" etc. refer to any reference system.

[0035] In addition, when referring to any dimension, relative dimension, etc., the numerical value or corresponding information of an element or feature (e.g., horizontal, range, etc.) should be considered to include a tolerance or error range that may be caused by various factors (e.g., process factors, internal or external influences, noise, etc.), even if no relevant description is specified. Moreover, the term "may" fully encompasses all the meanings of the term "can".

[0036] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the exemplary example embodiments belong. It will also be understood that terms (such as those defined in a common dictionary) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense, unless explicitly defined as such herein. For example, terms such as "component" or "unit" can be applied, for example, to a separate circuit or structure, an integrated circuit, a computing block of a circuit device, or any structure configured to perform the described function, as would be understood by one of ordinary skill in the art.

[0037] Features in the various embodiments of the present disclosure can be combined with each other partially or wholly, and can be technically related to each other or operate with each other. The embodiments can be implemented independently of each other or can be implemented together in an associated relationship.

[0038] Hereinafter, with reference to the accompanying drawings, various example embodiments of the present disclosure will be described in detail.

[0039] Figure 1 An example configuration of an optical film according to aspects of the present disclosure is shown.

[0040] Reference Figure 1 , in one or more example embodiments, the optical film 1 can be an element for blocking blue light that adversely affects the human body, and for example, can include a first optical layer 10, a second optical layer 20, and a third optical layer 30, but is not limited thereto. The second optical layer 20 can be disposed between the first optical layer 10 and the third optical layer 30.

[0041] The first optical layer 10 can be a base layer and has a concave pattern formed in its upper part. According to this example, when a concave pattern is formed in the upper part of the first optical layer 10, light incident on the upper part of the first optical layer 10 can be totally reflected at the boundary surface of the concave pattern. In one or more aspects, this total reflection can be intended to recycle light incident inside the optical film 1, and a detailed discussion will be provided later.

[0042] The second optical layer 20 can be disposed on the first optical layer 10 and is configured to convert light of a first band among the light transmitted through the first optical layer 10 into light of a second band greater than the first band. For example, the first band can include wavelengths from 380 nm to 450 nm, and the second band can include wavelengths from 460 nm to 780 nm, but is not limited thereto.

[0043] The third optical layer 30 may be disposed on the second optical layer 20 and configured to transmit light having a wavelength greater than or equal to a predetermined wavelength among the light transmitted through the second optical layer 20 and reflect light having a wavelength less than the predetermined wavelength toward the first optical layer 10.

[0044] As an example, the predefined wavelength may be a wavelength of 450 nm, but is not limited thereto.

[0045] Figure 2 is a diagram showing an example wavelength conversion of light transmitted through Figure 1 the second optical layer 20 shown.

[0046] Refer to Figure 2 , the second optical layer 20 may be used to perform a Stokes shift on the light from the first optical layer 10. For example, some deep blue light wavelengths in the range of 380 nm to 450 nm among the wavelengths of the light transmitted through the first optical layer 10 may be converted into blue light wavelengths in the range of 460 nm to 500 nm, but are not limited thereto. For example, the second optical layer 20 may convert blue light, which is harmful to the human body, having a wavelength in the range of 380 nm to 450 nm among visible light into light having a wavelength greater than the range of 380 nm to 450 nm, but is not limited thereto. For example, the second optical layer 20 may convert light having a wavelength in the range of 380 nm to 450 nm among the wavelengths of the light from the first optical layer 10 into light having a wavelength in the range of 460 nm to 780 nm, but is not limited thereto.

[0047] The second optical layer 20 may include a wavelength conversion material capable of converting light in a first band into light in a second band. For example, the wavelength conversion material may include any one of fluorescent dyes, fluorescent pigments, or quantum dots that absorb blue light and emit light having one or more wavelengths greater than blue light, but is not limited thereto.

[0048] For example, the fluorescent dye may include one or more of coumarin-based blue light blocking dyes, pyrazole-based blue light blocking dyes, and naphthalenedicarboximide-based blue light blocking dyes. For example, fluorescent pigments may use blue-based pigments such as GC19XPF Sapphire Blue MB, MP-BL6182 Blue Horizon Blue TM , A-17-N, Horizon Blue TM , ZQ-19Horizon Blue TM and so on.

[0049] For example, depending on the size of the quantum dots, due to the quantum confinement effect, the quantum dots can absorb light with a short wavelength and emit light with a long wavelength. Therefore, when the size of the quantum dots included in the second optical layer 20 is appropriately controlled, the second optical layer 20 including the quantum dots can absorb the blue light included in the incident light, convert one or more wavelengths of the blue light into one or more larger wavelengths, and then emit light with one or more larger wavelengths. For example, the quantum dots included in the second optical layer 20 can convert light with a wavelength in the range of 380 nm to 450 nm into light with a wavelength in the range of 460 nm to 780 nm, and then emit light with a wavelength in the range of 460 nm to 780 nm, but is not limited thereto.

[0050] For example, the quantum dots can include at least one of red quantum dots and green quantum dots, but is not limited thereto. This is because the light passing through the red quantum dots has wavelengths in the reduced blue band and the increased red band, and the light passing through the green quantum dots has wavelengths in the reduced blue band and the increased green band.

[0051] In this way, when the second optical layer 20 includes wavelength conversion materials such as fluorescent dyes, fluorescent pigments, and quantum dots, the light with a wavelength in the range of 380 nm to 450 nm among the wavelengths of the light reaching the second optical layer 20 can be converted into light with a wavelength greater than the wavelength in the range of 380 nm to 450 nm, and thereafter, light with a larger wavelength generated by the conversion can be emitted. For example, the wavelength conversion materials included in the second optical layer 20 can convert light with a wavelength in the range of 380 nm to 450 nm into light with a wavelength in the range of 460 nm to 780 nm, and then emit light with a wavelength in the range of 460 nm to 780 nm, but is not limited thereto.

[0052] The third optical layer 30 can be disposed on the second optical layer 20. The third optical layer 30 can be configured to selectively transmit light with a wavelength greater than or equal to a predetermined wavelength among the light transmitted through the second optical layer 20, and reflect light with a wavelength less than the predetermined wavelength toward the first optical layer 10. As an example, the predetermined wavelength can be a wavelength of 450 nm, but is not limited thereto. For example, the third optical layer 30 can transmit light with a wavelength of 450 nm or greater, and reflect light with a wavelength less than 450 nm in the direction where the first optical layer 10 is disposed, that is, in the downward direction in the plan view.

[0053] That is to say, the third optical layer 30 can more effectively block the blue light that has a harmful effect on the human body by filtering again the blue light with a wavelength less than 450 nm that has not been converted in the second optical layer 20.

[0054] The third optical layer 30 may be formed such that a plurality of film alternating layers having different refractive indices are stacked. As an example, the third optical layer 30 may have a structure in which one or more first films 31 having a first refractive index and one or more second films 32 having a second refractive index greater than the first refractive index are alternately stacked. For example, the third optical layer 30 may have a structure in which 10 or more first films 31 having a refractive index of 1.0 to 1.3 and 10 or more second films 32 having a refractive index of 1.6 to 1.7 are alternately stacked, but is not limited thereto. In this example, the third optical layer 30 may have a stack of 20 or more layers, but is not limited thereto.

[0055] Therefore, since the third optical layer 30 includes one or more first films 31 and one or more second films 32 having different refractive indices, the optical film 1 may have a structure in which the recycling of light can be achieved by selectively reflecting light having a specific wavelength and selectively transmitting light having the remaining wavelengths through the third optical layer 30. For example, the third optical layer 30 may include one or more first films 31 having a low refractive index and one or more second films 32 having a high refractive index, but is not limited thereto.

[0056] In addition, the effects of constructive or destructive interference of light may be changed according to the respective materials and stacked thicknesses of the one or more first films 31 having a low refractive index and the one or more second films 32 having a high refractive index, and thereby, the light transmittance may be changed. That is, the light transmittance may be adjusted by adjusting the materials and stacked thicknesses of the one or more first films 31 and the one or more second films 32.

[0057] For example, the one or more first films 31 and the one or more second films 32 may include organic or inorganic materials, but are not limited thereto. In another example, the one or more first films 31 may include inorganic materials, and the one or more second films 32 may include organic materials, but are not limited thereto. In an example in which one of the first film 31 and the second film 32 includes an inorganic material, the third optical layer 30 may prevent moisture and oxygen from outside the optical film 1.

[0058] As referred to above Figure 1 and Figure 2As described, the first optical layer 10 may be configured to receive light reflected from the third optical layer 30 and totally reflect the received light in the direction of the second optical layer 20 through the concave pattern. For example, the blue light filtered by the third optical layer 30 may be reflected downward, pass through the second optical layer 20, and reach the first optical layer 10. Then, the blue light reaching the first optical layer 10 may be totally reflected by the concave pattern, move backward toward the second optical layer 20, and reach the third optical layer 30. For example, by applying the structure configured with the third optical layer 30 and the first optical layer 10, blue light with a wavelength less than 450 nm can be effectively blocked through recycling in the optical film 1, but is not limited thereto. Therefore, blue light with a wavelength less than 450 nm can be reused or recycled.

[0059] In one or more aspects, the first optical layer 10 may include a base layer 11 and a pattern portion 12, but is not limited thereto. The pattern portion 12 may be disposed on the base layer 11, and the second optical layer 20 may be disposed on the pattern portion 12.

[0060] The base layer 11 may be a layer located at the bottom of the optical film 1 and may be configured to have a refractive index of 1.2 to 1.4, but is not limited thereto.

[0061] The pattern portion 12 may be disposed on the surface of the base layer 11. For example, the pattern portion 12 may be disposed on the top surface of the base layer 11 and may be configured to have a refractive index different from that of the base layer 11. For example, the pattern portion 12 may have a refractive index of 1.6 to 1.8, but is not limited thereto. As an example, the refractive index of the base layer 11 may be less than that of the pattern portion 12, but is not limited thereto. For example, the base layer 11 may have a refractive index of 1.2 to 1.4, but is not limited thereto.

[0062] Since the pattern portion 12 with a high refractive index is disposed on the surface of the base layer 11 with a low refractive index, the blue light reflected from the third optical layer 30 can be more effectively totally reflected at the interface between the base layer 11 and the pattern portion 12.

[0063] Figure 3 Schematically shows an example path of light passing through Figure 1 the optical film. Refer to Figure 3 , and the path of light passing through the optical film 1 is discussed as follows.

[0064] Light incident on the lower part of the optical film 1 can pass through the first optical layer 10 and then reach the second optical layer 20. Then, the second optical layer 20 can convert one or more wavelengths of blue light into one or more larger wavelengths by means of a wavelength conversion material and then emit light having one or more larger wavelengths. For example, the second optical layer 20 can convert light having wavelengths in the range of 380 nm to 450 nm among the wavelengths of the incident light into light having wavelengths in the range of 460 nm to 780 nm by means of a wavelength conversion material and then emit light having wavelengths in the range of 460 nm to 780 nm.

[0065] The resulting light having wavelengths in the range of 460 nm to 780 nm can reach the third optical layer 30. Then, the third optical layer 30 can transmit upward light having a wavelength of 450 nm or more and reflect back in the direction where the first optical layer 10 is located blue light having a wavelength less than 450 nm that has not been converted in the second optical layer 20.

[0066] The patterned portion 12 of the first optical layer 10 can completely reflect blue light having a wavelength less than 450 nm in the direction where the second optical layer 20 is provided. After that, the wavelength conversion material of the second optical layer 20 can convert blue light having a wavelength less than 450 nm into light having a higher wavelength, and then the converted light having a higher wavelength can reach the third optical layer 30. In this way, when blue light having a wavelength less than 450 nm reflected from the third optical layer 30 reaches the first optical layer 10, since the blue light that has reached the first optical layer 10 is totally reflected and shifted back to the second optical layer 20 and the third optical layer 30, blue light can be effectively blocked through such recycling in the optical film 1.

[0067] Figure 4 The configuration of a display device 100 according to an exemplary embodiment of the present disclosure is shown. Discussion of examples is provided by focusing on the differences from the previously described examples. Figure 4 of the examples.

[0068] Reference Figure 4 , in one or more exemplary embodiments, the display device 100 may include a backlight unit 110, a substrate portion 120, an optical film 1, a liquid crystal layer 130, a color filter 140, a cover portion 150, and the like.

[0069] The backlight unit 110 can be used to emit backlight when located at the back or rear of the display panel and, although not shown, may include at least one light source and a light guide plate. The backlight unit 110 can be, for example, a direct - type backlight unit 110 or an edge - type backlight unit 110 depending on the light source position, but is not limited thereto. Figure 4The backlight unit 110 can be applied to both a direct - type backlight unit 110 and an edge - type backlight unit 110, but is not limited thereto.

[0070] The base portion 120 can be used to support the optical film 1 and is disposed on the backlight unit 110. That is, the base portion 120 can be disposed between the optical film 1 and the backlight unit 110. For example, the base portion 120 can be configured with a substrate formed of glass, or a plastic film including any one of polymethyl methacrylate (PMMA), polyimide (PI), or polyethylene terephthalate (PET), or a combination of two or more of these materials, but is not limited thereto. The base portion 120 can also include a polarizer.

[0071] The optical film 1 can be used to block blue light included in the light provided from the backlight unit 110, and includes a first optical layer 10, a second optical layer 20, and a third optical layer 30. For example, the optical film 1 can be disposed on the polarizer of the base portion 120. For example, the optical film 1 can be disposed between the polarizer of the base portion 120 and the liquid crystal layer 130.

[0072] The first optical layer 10 can be disposed on the base portion 120 and has a concave pattern formed in the upper portion of the first optical layer 10. For example, the first optical layer 10 can include a base layer 11 having a refractive index of 1.2 to 1.4 and a concave pattern portion 12 having a refractive index greater than that of the base layer 11. For example, the concave pattern portion 12 is formed on the surface of the base layer 11 and has a refractive index of 1.6 to 1.8, but is not limited thereto.

[0073] The second optical layer 20 can be disposed on the first optical layer 10 and is configured to convert light in a first wavelength band among the light transmitted through the first optical layer 10 into light in a second wavelength band greater than the first wavelength band. As an example, the second optical layer 20 can use a wavelength - converting material to convert harmful blue light in the visible light with a wavelength in the range of 380 nm to 450 nm into light with a wavelength in the range of 380 nm to 450 nm, but is not limited thereto. For example, the second optical layer 20 can use a wavelength - converting material to convert light with a wavelength in the range of 380 nm to 450 nm among the wavelengths of the light from the first optical layer 10 into light with a wavelength in the range of 460 nm to 780 nm, but is not limited thereto.

[0074] The third optical layer 30 may be disposed on the second optical layer 20 and may be configured to transmit light having a wavelength greater than or equal to a predetermined wavelength among the light transmitted through the second optical layer 20, and reflect light having a wavelength less than the predetermined wavelength toward the first optical layer 10. For example, the third optical layer 30 may be configured to transmit light having a wavelength of 450 nm or greater and reflect light having a wavelength less than 450 nm to the first optical layer 10. The light reflected by the third optical layer 30 to the first optical layer 10 may be completely reflected by the concave pattern portion 12 without passing through the first optical layer 10, and then move back to the second optical layer 20.

[0075] In this way, when recycling harmful blue light having a wavelength less than 450 nm in the first optical layer 10, the second optical layer 20, and the third optical layer 30, the blue light can be effectively blocked. In addition, since the display device 100 is configured to have such a structure in which light having a wavelength in the range of 380 nm to 450 nm is converted into light having a higher wavelength without being absorbed and removed, the display device 100 to which this structure is applied can provide the advantage of blocking wavelengths in a desired band without causing brightness degradation.

[0076] The liquid crystal layer 130 may be disposed on the optical film 1. Specifically, the liquid crystal layer 130 may be disposed on the third optical layer 30 of the optical film 1. For example, the liquid crystal layer 130 may include a plurality of thin and long liquid crystals, and the arrangement direction of the liquid crystals may be changed by applying an electric field, thereby adjusting the corresponding light transmittance of each pixel region. The liquid crystal layer 130 may also include not only liquid crystals but also a substrate and at least one thin film transistor for driving the liquid crystals, but is not limited thereto.

[0077] The color filter 140 may be disposed on the liquid crystal layer 130. For example, the color filter 140 may include a plurality of color patterns such as red, green, and blue patterns that are sequentially and repeatedly arranged corresponding to each pixel region, but is not limited thereto. In one or more aspects, a black matrix layer may be disposed between the color patterns to prevent light leakage.

[0078] The cover portion 150 may be used to protect the components located below the cover portion 150 from external impacts and scratches, and prevent unwanted substances or particles or moisture from penetrating inside, and may be disposed on the color filter 140.

[0079] The cover portion 150 may include a material having impact resistance and light transmittance. For example, the cover portion 150 may be configured with a substrate formed of glass, or configured with a plastic film including any one of polymethyl methacrylate (PMMA), polyimide (PI), or polyethylene terephthalate (PET), or a combination of two or more of these materials, but is not limited thereto. The cover portion 150 may also include a polarizer, and the polarizer may be located on top of the cover portion 150.

[0080] Figure 5 Shows the configuration of the display device 100A according to Comparative Example 1.

[0081] Reference Figure 5 , it should be understood that the display device 100A according to Comparative Example 1 has the same configuration as the display device 100 according to the Figure 4 example embodiment, except that the display device 100A does not include an optical film between the substrate portion 120 and the liquid crystal layer 130. For example, the display device 100 may include a backlight unit 110, a substrate portion 120, a liquid crystal layer 130, a color filter 140, a cover portion 150, etc.

[0082] Figure 6 Shows the configuration of the display device 100B according to Comparative Example 2.

[0083] Reference Figure 6 , it should be understood that the display device 100B according to Comparative Example 2 has the same configuration as the display device 100 according to the Figure 4 example embodiment, except that the display device 100A includes a light filtering portion 160 between the substrate portion 120 and the liquid crystal layer 130 instead of the Figure 4 optical film 1. For example, the display device 100 may include a backlight unit 110, a substrate portion 120, a light filtering portion 160, a liquid crystal layer 130, a color filter 140, a cover portion 150, etc.

[0084] Figure 7 Is a diagram showing an example of the amount of light with respect to wavelength in the display device 100 according to the Figure 4 example embodiment and the display devices (100A and 100B) of Comparative Example 1 according to Figure 5 and Comparative Example 2 according to Figure 6 .

[0085] Reference Figure 7 , it can be seen that the display device 100 according to the Figure 4 example embodiment has better blue light blocking efficiency than the display device 100A according to Comparative Example 1 and the display device 100B according to Comparative Example 2. For example, the proportion of harmful blue light with a wavelength of 380 nm to 450 nm is as shown in Table 1 below.

[0086] [Table 1]

[0087] Blue light maximum Ratio of harmful blue light wavelengths Comparative Example 1 457 nm 36.8％ Comparative Example 2 457 nm 19.5％ Example embodiment 464 nm 11.5％

[0088] As can be seen from Table 1 above, the blue light blocking efficiency of the display device 100 according to the example embodiment of the present disclosure is superior to that of the display device 100A of Comparative Example 1 and the display device 100B of Comparative Example 2.

[0089] Thus, the reason for the better blue light blocking efficiency of the display device 100 according to the exemplary embodiment is that the display device 100A of Comparative Example 1 does not include an element for blocking blue light, and thus allows blue light to pass through.

[0090] In addition, the reason for the relatively poor blue light blocking efficiency of the display device 100B of Comparative Example 2 is that since only the yellow filter unit 160 is used to block blue light, some blue light is allowed to transmit through the filter unit 160 without being blocked by the filter unit 160. In the case of the display device 100B of Comparative Example 2, since the filter unit 160 including as an element for blocking blue light is included, the harmful blue light wavelength is reduced, and compared with Comparative Example 1, the ratio of the harmful blue light wavelength is reduced. However, since the filter unit 160 absorbs blue light wavelengths of about 450 nm to 500 nm in addition to the harmful blue light wavelengths, and as Figure 7 shown, the blue light wavelengths between 450 nm and 500 nm are greatly reduced. Therefore, in the display device 100B of Comparative Example 2, compared with the display device 100A of Comparative Example 1, the ratio of the harmful blue light wavelength is reduced.

[0091] On the contrary, since the display device 100 according to the exemplary embodiment has a recycling structure in which the blue light reflected from the third optical layer 30 reaches the first optical layer 10, and then is totally reflected and moves back to the second optical layer 20 and the third optical layer 30, the display device 100 can provide the advantages of improved blue light blocking efficiency and reduced light loss through light recycling compared with Comparative Examples 1 and 2.

[0092] The exemplary embodiment described above will be briefly described as follows.

[0093] According to the exemplary embodiment described herein, an optical film can be provided, the optical film including: a first optical layer having a concave pattern formed in an upper portion thereof; a second optical layer disposed on the first optical layer and configured to convert light in a first band among the light transmitted through the first optical layer into light in a second band greater than the first band; and a third optical layer disposed on the second optical layer and configured to transmit light having a wavelength greater than or equal to a predetermined wavelength among the light transmitted through the second optical layer and reflect light having a wavelength less than the predetermined wavelength toward the first optical layer.

[0094] In one or more aspects, the first band may include wavelengths of 380 nm to 450 nm, and the second band may include wavelengths of 460 nm to 780 nm.

[0095] In one or more aspects, the predetermined wavelength may be a wavelength of 450 nm.

[0096] In one or more aspects, the first optical layer may be configured to receive light reflected from the third optical layer and completely reflect the received light in the direction of the second optical layer through the concave pattern.

[0097] In one or more aspects, the first optical layer may include a base layer and a pattern portion formed on the surface of the base layer, and the base layer and the pattern portion may have different refractive indices.

[0098] In one or more aspects, the refractive index of the pattern portion may be greater than the refractive index of the base layer.

[0099] In one or more aspects, the base layer may have a refractive index of 1.2 to 1.4, and the pattern portion may have a refractive index of 1.6 to 1.8.

[0100] In one or more aspects, the second optical layer may include a wavelength conversion material that can convert light in the first band into light in the second band.

[0101] In one or more aspects, the wavelength conversion material may include any one of a fluorescent dye, a fluorescent pigment, or a quantum dot.

[0102] In one or more aspects, the fluorescent dye may include one or more of a coumarin-based blue light blocking dye, a pyrazole-based blue light blocking dye, and a naphthalenedicarboximide-based blue light blocking dye.

[0103] In one or more aspects, the quantum dot may include at least one of a red quantum dot and a green quantum dot.

[0104] In one or more aspects, the third optical layer may be formed such that a plurality of film alternating layers having different refractive indices are stacked.

[0105] In one or more aspects, the third optical layer may include one or more first films having a first refractive index and one or more second films having a second refractive index greater than the first refractive index.

[0106] In one or more aspects, the third optical layer may include one or more first films having a refractive index of 1.0 to 1.3 and one or more second films having a refractive index of 1.6 to 1.7.

[0107] According to an exemplary embodiment described herein, a display device may be provided. The display device includes: a backlight unit; a substrate portion disposed on the backlight unit; an optical film disposed on the substrate portion; a liquid crystal layer disposed on the optical film; and a color filter disposed on the liquid crystal layer. The optical film includes: a first optical layer having a concave pattern formed in an upper portion thereof; a second optical layer disposed on the first optical layer and configured to convert light in a first band among the light transmitted through the first optical layer into light in a second band greater than the first band; and a third optical layer disposed on the second optical layer and configured to transmit light having a wavelength greater than or equal to a predetermined wavelength among the light transmitted through the second optical layer and reflect light having a wavelength less than the predetermined wavelength toward the first optical layer.

[0108] In one or more aspects, the first band may include wavelengths from 380 nm to 450 nm, the second band may include wavelengths from 460 nm to 780 nm, and the predetermined wavelength may be a wavelength of 450 nm.

[0109] In one or more aspects, the first optical layer may be configured to receive light reflected from the third optical layer and completely reflect the received light in a direction in which the second optical layer is disposed through the concave pattern.

[0110] In one or more aspects, the first optical layer may include a base layer and a pattern portion formed on a surface of the base layer, and the base layer and the pattern portion may have different refractive indices.

[0111] In one or more aspects, the refractive index of the pattern portion may be greater than the refractive index of the base layer.

[0112] In one or more aspects, the base layer may have a refractive index of 1.2 to 1.4, and the pattern portion may have a refractive index of 1.6 to 1.8.

[0113] In one or more aspects, the second optical layer may include a wavelength conversion material capable of converting light in the first band into light in the second band, and the wavelength conversion material may include any one of a fluorescent dye, a fluorescent pigment, or a quantum dot.

[0114] In one or more aspects, the fluorescent dye may include one or more of a coumarin-based blue light blocking dye, a pyrazole-based blue light blocking dye, and a naphthalimide-based blue light blocking dye.

[0115] In one or more aspects, the quantum dots may include at least one of red quantum dots and green quantum dots.

[0116] In one or more aspects, the third optical layer may be formed such that a plurality of film alternating layers having different refractive indices are stacked.

[0117] In one or more aspects, the third optical layer may include one or more first films having a first refractive index and one or more second films having a second refractive index greater than the first refractive index.

[0118] In one or more aspects, the third optical layer may include one or more first films having a refractive index of 1.0 to 1.3 and one or more second films having a refractive index of 1.6 to 1.7.

[0119] A display device according to one or more exemplary embodiments of the present disclosure may be applied to mobile devices, video phones, smart watches, watch phones, wearable devices, foldable devices, rollable devices, bendable devices, flexible devices, curved devices, variable devices, sliding devices, electronic notepads, e-books, portable multimedia players (PMPs), personal digital assistants (PDAs), MP3 players, mobile medical devices, desktop personal computers (PCs), laptop PCs, netbook computers, workstations, navigation devices, automotive navigation devices, automatic display devices, automotive devices, theater devices, theater display devices, televisions, wallpaper display devices, signage devices, game consoles, laptops, monitors, cameras, camcorders, household appliances, etc., but the embodiments of the present disclosure are not limited thereto.

[0120] The above description has been presented so that any person skilled in the art can make, use, and practice the technical features of the present invention, and has been provided in the context of a specific application and its requirements as an example. Various modifications, additions, and substitutions to the described embodiments will be apparent to those skilled in the art, and the principles described herein can be applied to other embodiments and applications without departing from the scope of the present invention. The above description and drawings provide examples of the technical features of the present invention for illustrative purposes only. That is, the disclosed embodiments are intended to illustrate the scope of the technical features of the present invention.

[0121] Cross-reference to related applications

[0122] This application claims the priority and benefits of Korean Patent Application No. 10-2023-0194022, filed with the Korean Intellectual Property Office on December 28, 2023, which is incorporated herein by reference in its entirety for all purposes as if fully set forth herein.

Claims

1. An optical film, comprising: a first optical layer, forming a concave pattern in an upper portion of the first optical layer; a second optical layer disposed on the first optical layer and configured to convert light in a first wavelength band among the light transmitted through the first optical layer into light in a second wavelength band larger than the first wavelength band; as well as A third optical layer is disposed on the second optical layer and is configured to transmit light having a wavelength greater than or equal to a predetermined wavelength among the light transmitted through the second optical layer and reflect light having a wavelength less than the predetermined wavelength toward the first optical layer.

2. The optical film according to claim 1, wherein The first wavelength band includes wavelengths of 380 nm to 450 nm, and the second wavelength band includes wavelengths of 460 nm to 780 nm.

3. The optical film according to claim 1, wherein The predetermined wavelength is a wavelength of 450 nm.

4. The optical film according to claim 1, wherein The first optical layer is configured to receive light reflected from the third optical layer and completely reflect the received light in a direction in which the second optical layer is disposed through the concave pattern.

5. The optical film according to claim 1, wherein The first optical layer includes a base layer and a pattern portion formed on a surface of the base layer, and the base layer and the pattern portion have different refractive indices.

6. The optical film according to claim 5, wherein: The refractive index of the pattern portion is greater than the refractive index of the base layer.

7. The optical film according to claim 5, wherein: The base layer has a refractive index of 1.2 to 1.4, and the pattern portion has a refractive index of 1.6 to 1.

8.

8. The optical film according to claim 1, wherein The second optical layer includes a wavelength conversion material capable of converting light in the first wavelength band into light in the second wavelength band.

9. The optical film according to claim 8, wherein: The wavelength conversion material includes any one of fluorescent dyes, fluorescent pigments or quantum dots.

10. The optical film according to claim 9, wherein: The fluorescent dye includes one or more of a coumarin-based blue light blocking dye, a pyrazol-based blue light blocking dye, and a naphthalimide-based blue light blocking dye.

11. The optical film according to claim 9, wherein: The quantum dots include at least one of red quantum dots and green quantum dots.

12. The optical film according to claim 1, wherein: The third optical layer is formed such that a plurality of films having different refractive indices are alternately stacked.

13. The optical film according to claim 1, wherein: The third optical layer includes one or more first films having a first refractive index and one or more second films having a second refractive index greater than the first refractive index.

14. The optical film according to claim 11, wherein: The third optical layer includes one or more first films having a refractive index of 1.0 to 1.3 and one or more second films having a refractive index of 1.6 to 1.

7.

15. A display device, comprising: Backlight unit; A base portion, the base portion being disposed on the backlight unit ； The optical film according to any one of claims 1 to 14, wherein the optical film is disposed on the substrate portion; a liquid crystal layer, wherein the liquid crystal layer is disposed on the optical film; as well as A color filter is disposed on the liquid crystal layer.

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