Filter member and lens

Abstract

This filter member, which is included in a member worn by a user, comprises a base material and one or more types of absorption dyes dispersed in the base material. The transmission spectrum of the filter member includes: a first valley where a first minimum wavelength is located within a range A1 of 400-450 nm; a second valley where a second minimum wavelength is located within a range A2 of 540-600 nm; and a third valley where a third minimum wavelength is located within a range A3 of 680-800 nm. The maximum value of transmittance in a range B1 of 350-400 nm is at least 2.5 times the transmittance at the first peak wavelength. The maximum value of transmittance in a range B2 of 450-540 nm is at least 3 times the transmittance at the second peak wavelength. The maximum value of transmittance in a range B3 of 600-680 nm is at least 1.6 times the transmittance at the third peak wavelength.

Description

Filter member and lens

[0001] The present invention relates to a filter member and a lens.

[0002] Patent Document 1 discloses a color adjustment filter for a display, which contains an absorbing dye to adjust the color of the display.

[0003] Japanese Patent Application Laid-Open No. 2003-36033

[0004] The present invention aims to provide a filter member and lens that can improve the visibility of both displays and objects.

[0005] A filter member according to one aspect of the present invention is provided in a member worn by a user, and includes a substrate and one or more types of absorbing dyes dispersed in the substrate. The transmission spectrum of the filter member has a first valley where a first minimum wavelength is located in a range of 400 nm to 450 nm, a second valley where a second minimum wavelength is located in a range of 540 nm to 600 nm, and a third valley where a third minimum wavelength is located in a range of 680 nm to 800 nm. The maximum transmittance of the filter member within a range of 450 nm or less is 2.5 times or more the transmittance of the filter member at the first minimum wavelength, the maximum transmittance of the filter member within a range of 450 nm or more and 540 nm or less is 3 times or more the transmittance of the filter member at the second minimum wavelength, and the maximum transmittance of the filter member within a range of 600 nm or more and 680 nm or less is 1.6 times or more the transmittance of the filter member at the third minimum wavelength.

[0006] A lens according to one aspect of the present invention is a lens for eyeglasses, sunglasses, or goggles, which includes the filter member according to the above aspect.

[0007] The filter member and lens according to the present invention can improve the visibility of both the display and the object.

[0008] FIG. 1 is a perspective view of a lens including a filter member according to an embodiment, and of eyeglasses including the lens. FIG. 2 is a diagram showing the configuration of an operating system including a lens according to an embodiment. FIG. 3 is a diagram showing the transmission characteristics of lenses according to Examples 1 and 2. FIG. 4 is a diagram showing the absorption characteristics of an absorbing pigment included in a filter member according to Example 1. FIG. 5 is a diagram showing the absorption characteristics of an absorbing pigment included in a filter member according to Example 2. FIG. 6A is a diagram showing the emission spectrum of a display. FIG. 6B is an xy chromaticity diagram for explaining the difference in the color gamut of a display depending on whether or not the filter member according to Examples 1 and 2 is present. FIG. 7A is a diagram showing the spectrum of sunlight. FIG. 7B is a diagram showing the spectrum of transmitted light of sunlight that has passed through the filter member according to Examples 1 and 2. FIG. 8A is a diagram showing the spectrum of white light from a white LED. FIG. 8B is a diagram showing the spectrum of transmitted light of white light that has passed through the filter member according to Examples 1 and 2. FIG. 9 is a perspective view of a lens including a filter member according to a modified embodiment, and of eyeglasses including the lens.

[0009] Below, filter members and lenses according to embodiments of the present invention will be described in detail with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component arrangements and connection forms, steps, and step sequences shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components not recited in the independent claims will be described as optional components.

[0010] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, for example, the scales of the figures do not necessarily match. Furthermore, in each figure, substantially the same components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0011] Furthermore, in this specification, terms indicating the relationship between elements, terms indicating the shape of elements, and numerical ranges are not expressions that express only the strict meaning, but also expressions that mean that a substantially equivalent range, for example, a difference of about several percent, is included. Furthermore, when "about" is used together with a numerical value, it means a range of ±1% of the numerical value, but in some cases it may mean a range of ±2%, ±3, or ±5%.

[0012] Furthermore, in this specification, ordinal numbers such as "first" and "second" do not refer to the number or order of components unless otherwise specified, but are used for the purpose of avoiding confusion and distinguishing between components of the same type.

[0013] (Embodiment) [Filter Member and Lens] First, the configurations of the filter member and lens according to the embodiment will be described with reference to FIGS. 1 and 2. FIG.

[0014] Fig. 1 is a perspective view showing the appearance of a lens 10 including a filter member according to the present embodiment, and eyeglasses 1 including the lens 10. Fig. 2 is a diagram showing the configuration of a working system 100 including the lens 10 according to the present embodiment.

[0015] The eyeglasses 1 shown in FIG. 1 include two lenses 10. The two lenses 10 are for the left eye and the right eye, respectively. The two lenses 10 have the same optical characteristics. For example, the lenses 10 include a filter member that absorbs and emits part of the incident light when transmitting the light. The lenses 10 do not necessarily have the function of focusing and diverging light. The specific configuration of the filter member included in the lenses 10 will be described later.

[0016] The glasses 1 are an example of a component worn by a user U. Specifically, the glasses 1 are glasses for the operation system 100 as shown in FIG. 2. That is, the glasses 1 are an example of a wearable product used, for example, when viewing a display 110. Alternatively, the glasses 1 may be glasses for vision correction or so-called fashion glasses.

[0017] The work system 100 shown in FIG. 2 is a system for having a user U perform a predetermined work. The predetermined work is work that uses the display 110. Specifically, the predetermined work is so-called desk work, playing games such as video games, e-sports, etc. Alternatively, the predetermined work may be creating or editing content such as documents, illustrations, images, or videos, or office work. Alternatively, the predetermined work may be viewing or watching images such as photographs or videos.

[0018] As shown in Fig. 2, the work system 100 includes a lens 10, a display 110, and a lighting device 120. The lens 10 is a lens for eyeglasses, but may also be a lens for sunglasses or goggles. Specifically, the lens 10 is used in eyeglasses 1 worn by a user U. The work system 100 is constructed, for example, in an indoor space where sunlight (natural light) enters through a window. A potted plant 130, as well as fixtures and equipment (not shown) are arranged in the indoor space.

[0019] The display 110 is a display device that displays images or videos. The display 110 is, for example, a liquid crystal display device or an organic electroluminescence (EL) display device. The liquid crystal display device generally includes a light source that emits white light. The light source includes, for example, a white LED (Light Emitting Diode). The white LED includes, for example, a blue LED and a yellow phosphor. The yellow phosphor emits yellow light by wavelength-converting a portion of the blue light emitted from the blue LED. The blue light that has not been wavelength-converted and the yellow light are combined to form white light. The display 110 may also be a display device that includes light-emitting elements corresponding to each of RGB.

[0020] The lighting device 120 is a device that illuminates an indoor space. As shown in Fig. 2, the lighting device 120 is, for example, a ceiling light attached to a ceiling, and emits white light toward the floor surface (downward). The lighting device 120 may be a downlight, a spotlight, or a lighting device installed on a wall or floor.

[0021] The lighting device 120 includes, for example, a white LED. The white LED includes a blue LED and a yellow phosphor. The yellow phosphor converts the wavelength of part of the blue light emitted from the blue LED, thereby emitting yellow light. The blue light that has not been wavelength-converted and the yellow light are combined to produce white light.

[0022] The user U works in an environment illuminated by white light from the lighting device 120 and / or sunlight coming in through a window. The user U may look at the display 110, or may look at an object other than the display 110, such as a document placed on a desk or a houseplant 130. When looking at the display 110, light emitted from the display 110 enters the eyes of the user U via the glasses 1 (lenses 10). When looking at an object other than the display 110, white light from the lighting device 120 and / or sunlight reflected by the object enters the eyes of the user U via the glasses 1.

[0023] In this way, the object that the user U sees changes depending on the situation, and the light that enters the eyes of the user U also changes. For this reason, the filter member is required to improve not only the visibility of the display 110, but also the visibility of objects other than the display 110. Note that improving the visibility of the display 110 means widening the color gamut of the display 110. Also, improving the visibility of objects other than the display 110 means making the colors of the objects more vivid and / or increasing the color temperature of white, thereby enhancing the perceived whiteness of white objects.

[0024] The vividness of a color can be expressed by the feeling of contrast index (FCI) of the transmitted light when equal-energy white light is passed through a filter member. The larger the FCI value, the higher the color reproducibility, indicating that the color of an object can be reproduced more vividly. The whiteness can be expressed by the chroma value of the transmitted light when equal-energy white light is passed through a filter member. The chroma value can be used as an index that indicates that the lower the value, the whiter the object, i.e., the whiter the object appears.

[0025] 1 and 2 illustrate eyeglasses 1 equipped with lenses 10 as an example of a wearable product, but the wearable product equipped with lenses 10 is not limited to eyeglasses 1. For example, the wearable product equipped with lenses 10 may be sunglasses or goggles. The wearable product equipped with lenses 10 may be a dedicated product for a game system, or may be a general-purpose product used in everyday life other than gaming.

[0026] Although the working system 100 constructed in an indoor space is shown here, the present invention is not limited to this. The display 110 may be attached to the exterior wall of a building, and the user U may be a person who is outside and not performing any particular work.

[0027] [Filter Member] Next, a specific configuration of the filter member provided in the lens 10 will be described.

[0028] In the present embodiment, the lens 10 is the filter member itself, but is not limited to this. The lens 10 may also include a filter member and a functional film (e.g., a protective film) provided on the surface of the filter member. The following description will be given taking as an example a case where the lens 10 is the filter member itself.

[0029] As shown in Fig. 1, the filter member (lens 10) includes a substrate 11 and one or more types of absorbing dyes 12 dispersed in the substrate 11. Fig. 1 shows an enlarged schematic cross section of a portion of the filter member.

[0030] The substrate 11 is a light-transmitting plate-like member. The substrate 11 is, for example, a resin substrate formed by molding a transparent resin material into a predetermined shape. Specifically, the substrate 11 contains polycarbonate resin or acrylic resin as a main component. Note that "containing as a main component" means that the proportion (mass %) of the mass of the polycarbonate resin or acrylic resin relative to the total mass of the substrate 11 exceeds 50%. In this embodiment, the substrate 11 is substantially composed of polycarbonate resin or acrylic resin. The resin material used to form the substrate 11 may be an epoxy resin, a urethane resin, polysilazane, siloxane, allyl diglycol carbonate (CR-39), or a polysiloxane composite acrylic resin.

[0031] The thickness of the substrate 11 is, for example, 1 mm or more and 3 mm or less. The substrate 11 may be a flat plate or a curved plate having a convex or concave surface. For example, the substrate 11 may have a shape that realizes a lens function that focuses or diffuses light, like a convex or concave lens. In other words, the thickness of the substrate 11 does not need to be uniform within the surface, and may vary depending on the location. The size and shape of the substrate 11 are, for example, a size and shape that are suitable for the eyeglasses 1 that can be worn by a person.

[0032] The absorbing dye 12 is a dye material that selectively absorbs light in a predetermined wavelength band. Specific examples of the absorption spectrum of the absorbing dye 12 will be described later.

[0033] The absorbing dye 12 is, for example, uniformly dispersed inside the substrate 11. Specifically, the absorbing dye 12 is uniformly dispersed throughout the thickness and surface directions of the substrate 11. The absorbing dye 12 may be dispersed only in a partial region inside the substrate 11. For example, when the main surface of the substrate 11 is viewed from the front, the absorbing dye 12 may be dispersed only in the central region of the substrate 11. Alternatively, the absorbing dye 12 may be dispersed only in the surface layer portion of one surface of the substrate 11 in the thickness direction.

[0034] The absorbing dye 12 may be, for example, a merocyanine dye, a phthalocyanine dye, a porphyrin dye, or a methine dye. Here, an A-type dye is a dye having A as its basic skeleton (parent structure). By introducing various substituents into the basic skeleton of the dye, it becomes possible to adjust the absorption wavelength and / or absorbance. As a result, an absorbing dye 12 having a desired absorption spectrum can be realized.

[0035] In this embodiment, the filter member contains multiple types of absorbing dyes 12. By adjusting the type, number, content, and mixing ratio of the absorbing dyes 12, the optical characteristics (transmission spectrum) of the filter member can be adjusted.

[0036] [Transmission Spectrum] Next, the transmission spectrum of the filter member will be described with reference to specific examples.

[0037] Fig. 3 is a diagram showing the transmission characteristics of the filter members according to Examples 1 and 2. In Fig. 3, the horizontal axis represents wavelength (unit: nm) and the vertical axis represents transmittance (unit: %).

[0038] The transmission spectrum of the filter member according to Examples 1 and 2 includes four large valleys of transmittance. The transmission spectrum of the filter member includes a large peak of transmittance between the four valleys. In this specification, a "large valley" refers to a valley where the transmittance is less than 50%. Hereinafter, a valley with a large transmittance will be referred to as a "transmittance valley" or simply as a "valley." Furthermore, in this specification, a "large peak" refers to a peak where the transmittance is 50% or more. Hereinafter, a peak with a large transmittance will be referred to as a "transmittance peak" or simply as a "peak" or "peak."

[0039] Specifically, as shown in Fig. 3, the transmission spectrum of the filter member includes transmittance valleys (first valley V1, second valley V2, and third valley V3) in three ranges (wavelength bands) A1, A2, and A3, respectively. These first valley V1, second valley V2, and third valley V3 are formed due to the absorption spectra of one or more types of absorbing dyes contained in the filter member.

[0040] Specifically, range A1 is a range of 400 nm to 450 nm, and the minimum wavelength λ1 of the first valley V1 is included in range A1. The minimum wavelength is the wavelength at which the transmittance is minimum within a predetermined range (e.g., range A1). The transmittance at the minimum wavelength λ1 is, for example, 10% to 20%. The transmittance at the minimum wavelength λ1 may be 13% or more or 17% or less.

[0041] The half-width of the first valley V1 is 50 nm or less, but may be 40 nm or less, 30 nm or less, or 20 nm or less. The half-width of the first valley V1 is, for example, 10 nm or more, but is not limited to this. The half-width of the valley corresponds to the width of the wavelength at the median between the baseline and the minimum value of the valley in the transmission spectrum. The baseline of the valley can be considered to be the larger of the maximum value of the transmittance of the peak on the short-wavelength side of the valley and the maximum value of the transmittance of the peak on the long-wavelength side.

[0042] The range A2 is 540 nm or more and 600 nm or less, and the minimum wavelength λ2 of the second valley V2 is included in the range A2. The transmittance at the minimum wavelength λ2 is, for example, 10% or more and 30% or less. The transmittance at the minimum wavelength λ2 may be 15% or more, or 20% or more. The transmittance at the minimum wavelength λ2 may be 25% or less, or 20% or less.

[0043] The half width of the second valley V2 is 60 nm or less, but may be 50 nm or less, 40 nm or less, 30 nm or less, or 20 nm or less. The half width of the second valley V2 is, for example, 10 nm or more, but is not limited to this.

[0044] Range A3 is a range of 680 nm or more and 800 nm or less, and includes the minimum wavelength λ3 of the third valley V3. The transmittance at the minimum wavelength λ3 is, for example, 30% or more and 60% or less. The transmittance at the minimum wavelength λ3 may be 40% or more, or 50% or more. The transmittance at the minimum wavelength λ3 may be 50% or less, or 40% or less.

[0045] The half width of the third valley V3 is 60 nm or less, but may be 50 nm or less, 40 nm or less, 30 nm or less, or 20 nm or less. The half width of the third valley V3 is 10 nm or more, but is not limited to this.

[0046] Furthermore, a fourth valley V4 is included in a range of wavelengths shorter than the range A1. The fourth valley V4 is formed due to the transmission spectrum of the substrate 11. Note that the fourth valley V4 may also be formed due to the absorption spectrum of the absorbing dye. In the fourth valley V4, for example, the transmittance is substantially 0% at 380 nm.

[0047] As shown in Figure 3, the transmission spectrum of the filter member includes four peaks P1, P2, P3, and P4. The peak wavelength λa of peak P1 is located on the shorter wavelength side than the minimum wavelength λ1 of the first valley V1. Note that the peak wavelength is the wavelength at which transmittance is maximized within a predetermined range. The peak wavelength λb of peak P2 is located between the minimum wavelength λ1 of the first valley V1 and the minimum wavelength λ2 of the second valley V2. The peak wavelength λc of peak P3 is located between the minimum wavelength λ2 of the second valley V2 and the minimum wavelength λ3 of the third valley V3. The peak wavelength λd of peak P4 is located on the longer wavelength side than the minimum wavelength λ4 of the third valley V3.

[0048] Furthermore, the maximum value of the transmittance within range B1 is 2.5 times or more the transmittance at the minimum wavelength λ1. Range B1 is a range of 350 nm or more and 400 nm or less. The maximum value of the transmittance within range B1 may be 3 times or more, 3.5 times or more, 4 times or more, 4.5 times or more, or 5 times or more the transmittance at the minimum wavelength λ1. The maximum value of the transmittance within range B1 is 50% or more, but may also be 60% or more, or 70% or more. The peak wavelength λa of peak P1 may be included within range B1.

[0049] The maximum transmittance within range B2 is three times or more the transmittance at the minimum wavelength λ2. Range B2 is a range of 450 nm or more and 540 nm or less. Note that the maximum transmittance within range B2 may be 3.5 times or more, 4 times or more, 4.5 times or more, or even 5 times or more the transmittance at the minimum wavelength λ2. The maximum transmittance within range B2 is 70% or more, but may also be 80% or more, or 90% or more.

[0050] The maximum transmittance within range B3 is 1.6 times or more the transmittance at the minimum wavelength λ3. Range B3 is a range of 600 nm or more and 680 nm or less. The maximum transmittance within range B3 may be 1.8 times or more, 2 times or more, or 2.5 times or more the transmittance at the minimum wavelength λ3. The maximum transmittance within range B3 is 70% or more, but may also be 80% or more, or 90% or more.

[0051] The luminous transmittance of the filter member is 60% or more. Luminous transmittance is also referred to as visible light transmittance. The luminous transmittance is the ratio of the transmittance of light in the entire visible light band from 380 nm to 780 nm to the sum of the products multiplied by the spectral relative luminous efficiency function. When the filter member has a high luminous transmittance, a sufficient amount of light can be ensured to reach the eyes when viewing the display 110 or an object through the filter member (lens 10). The luminous transmittance of the filter member may be 65% or more, 70% or more, or 75% or more.

[0052] The absorption spectrum of the absorbing dye contained in the filter member and the specific transmission spectrum of the filter material will be described below for each of Examples 1 and 2.

[0053] Example 1 The filter member according to Example 1 contains five types of absorbing dyes C1, C2, C3, C4, and C5 as the absorbing dye 12. First, the absorption spectra of the absorbing dyes C1 to C5 will be described below with reference to FIG.

[0054] Fig. 4 is a diagram showing the absorption characteristics of five types of absorbing dyes C1, C2, C3, C4, and C5 contained in the filter member of Example 1. In Fig. 4, the horizontal axis represents wavelength (unit: nm), and the vertical axis represents transmittance (unit: %). The absorption spectrum shown in Fig. 4 is obtained by measuring the transmittance of a transparent substrate (acrylic substrate) in a state where a predetermined amount of absorbing dye is dispersed inside the transparent substrate. Fig. 4 shows the transmittance converted assuming that there is no light absorption by the transparent substrate.

[0055] The absorbing dye C1 is a porphyrin copper complex that mainly absorbs light in the vicinity of 420 nm. The absorbing dye C1 used in Example 1 is an example of a first absorbing dye having an absorption peak (first absorption peak) whose absorption peak wavelength is located within a range A1 of 400 nm or more and 450 nm or less. Specifically, as shown by the thick solid line in Figure 4, the absorbing dye C1 has an absorption peak wavelength of approximately 420 nm, and the transmittance at the absorption peak wavelength is approximately 26%.

[0056] The half-width of the absorption peak (first absorption peak) of the absorber dye C1 is, for example, 50 nm or less, but may also be 40 nm or less, 30 nm or less, or 20 nm or less. The half-width of the absorption peak corresponds to the wavelength width at the median between the baseline and minimum transmittance in the transmission spectrum. In the example shown in FIG. 4 , the baseline transmittance for the absorber dye C1 is approximately 100%, and the minimum transmittance is approximately 26%. Therefore, the half-width is the wavelength width of the absorption peak when the transmittance is approximately 63%, and is specifically approximately 18 nm (= approximately 429 nm - approximately 411 nm).

[0057] Furthermore, in the absorption spectrum of the absorbing dye C1, at least within the visible light band (range of 380 nm to 780 nm), the transmittance is 95% or more in the range of about 390 nm or less and in the range of about 445 nm or more (excluding the range of about 535 nm to about 550 nm). In other words, the absorbing dye C1 does not substantially absorb light in these wavelength ranges.

[0058] The absorption dye C2 is a tetraazaporphyrin metal complex that mainly absorbs light in the vicinity of 585 nm. The absorption dye C2 used in Example 1 is an example of a second absorption dye having an absorption peak (second absorption peak) whose absorption peak wavelength is located within the range A2 of 540 nm to 600 nm. Specifically, as shown by the dashed line in Figure 4, the absorption peak wavelength of the absorption dye C2 is approximately 580 nm, and the transmittance at the absorption peak wavelength is approximately 40%.

[0059] The half-width of the absorption peak (second absorption peak) of the absorber dye C2 is, for example, 60 nm or less, but may be 50 nm or less, 40 nm or less, 30 nm or less, or 20 nm or less. In the example shown in Figure 4, the baseline transmittance for the absorber dye C2 is approximately 100%, and the minimum transmittance is approximately 40%. Therefore, the half-width is the wavelength width of the absorption peak when the transmittance is approximately 70%, and is specifically approximately 23 nm (= approximately 593 nm - approximately 570 nm).

[0060] Furthermore, in the absorption spectrum of the absorbing dye C2, at least within the visible light band (range of 380 nm to 780 nm), the transmittance is 95% or more in the range of about 510 nm or less and in the range of about 605 nm or more, i.e., the absorbing dye C2 does not substantially absorb light in these wavelength ranges.

[0061] The absorption dye C3 is a phthalocyanine copper complex that mainly absorbs light in the vicinity of 715 nm. The absorption dye C3 used in Example 1 is an example of a third absorption dye having an absorption peak (third absorption peak) whose absorption peak wavelength is located within a range A3 of 680 nm or more and 800 nm or less. Specifically, as shown by the dotted line in Figure 4, the absorption peak wavelength of the absorption dye C3 is approximately 715 nm, and the transmittance at the absorption peak wavelength is approximately 59%.

[0062] The half-width of the absorption peak (third absorption peak) of the absorber dye C3 is, for example, 60 nm or less, but may also be 50 nm or less, 40 nm or less, 30 nm or less, or 20 nm or less. In the example shown in Figure 4, the baseline transmittance for the absorber dye C3 is approximately 100%, and the minimum transmittance is approximately 59%. Therefore, the half-width is the wavelength width of the absorption peak when the transmittance is approximately 80%, and is specifically approximately 33 nm (= approximately 733 nm - approximately 700 nm).

[0063] Furthermore, in the absorption spectrum of the absorbing dye C3, at least within the visible light band (range of 380 nm to 780 nm), the transmittance is 95% or more in the range of about 610 nm or less and in the range of about 750 nm or more, i.e., the absorbing dye C3 does not substantially absorb light in these wavelength ranges.

[0064] The absorber dye C4 is a porphyrin vanadium complex that mainly absorbs light in the vicinity of 430 nm. The absorber dye C4 used in Example 1 is an example of a fourth absorber dye having an absorption peak wavelength located within the range A1 of 400 nm or more and 450 nm or less. The absorber dye C4 has a longer absorption peak wavelength than the absorber dye C1. Specifically, as shown by the thin solid line in Figure 4, the absorber dye C4 has an absorption peak wavelength of approximately 430 nm, and the transmittance at the absorption peak wavelength is approximately 56%.

[0065] The half-width of the absorption peak (fourth absorption peak) of the absorber dye C4 is, for example, 50 nm or less, but may also be 40 nm or less, 30 nm or less, or 20 nm or less. In the example shown in Figure 4, the baseline transmittance for the absorber dye C4 is approximately 100%, and the minimum transmittance is approximately 56%. Therefore, the half-width is the wavelength width of the absorption peak when the transmittance is approximately 78%, and specifically, is approximately 19 nm (= approximately 439 nm - approximately 420 nm).

[0066] Furthermore, in the absorption spectrum of the absorbing dye C4, at least within the visible light band (range of 380 nm to 780 nm), the transmittance is 95% or more in the range of approximately 400 nm or less and in the range of approximately 450 nm or more, i.e., the absorbing dye C4 does not substantially absorb light in these wavelength ranges.

[0067] The absorbing dye C5 is a tetraazaporphyrin copper complex that mainly absorbs light in the vicinity of 595 nm. The absorbing dye C5 used in Example 1 is an example of a fifth absorbing dye having an absorption peak wavelength located within the range A2 of 540 nm or more and 600 nm or less. The absorbing dye C5 has a longer absorption peak wavelength than the absorbing dye C2. Specifically, as shown by the two-dot chain line in Figure 4, the absorbing dye C5 has a peak absorption wavelength of approximately 595 nm, and the transmittance at the peak absorption wavelength is approximately 50%.

[0068] The half-width of the absorption peak (fifth absorption peak) of the absorber dye C5 is, for example, 60 nm or less, but may also be 50 nm or less, 40 nm or less, 30 nm or less, or 20 nm or less. In the example shown in Figure 4, the baseline transmittance for the absorber dye C5 is approximately 100%, and the minimum transmittance is approximately 50%. Therefore, the half-width is the wavelength width of the absorption peak when the transmittance is approximately 75%, and specifically, is approximately 23 nm (= approximately 604 nm - approximately 581 nm).

[0069] Furthermore, in the absorption spectrum of the absorbing dye C5, at least within the visible light band (range of 380 nm to 780 nm), the transmittance is 95% or more in the range of about 530 nm or less and in the range of about 620 nm or more, i.e., the absorbing dye C5 does not substantially absorb light in these wavelength ranges.

[0070] The filter member of Example 1 contains five types of absorbing pigments C1, C2, C3, C4, and C5 in predetermined ratios. The transmission spectrum of the filter member can be adjusted by adjusting the content of each absorbing pigment. The filter member of Example 1 contains the five types of absorbing pigments C1, C2, C3, C4, and C5 in a weight ratio of C1:C2:C3:C4:C5=5:15:10:2:5. More specifically, the filter member contains 7.5 ppm of absorbing pigment C1, 22.5 ppm of absorbing pigment C2, 15 ppm of absorbing pigment C3, 3 ppm of absorbing pigment C4, and 7.5 ppm of absorbing pigment C5 (designed for a 2 mm thick plate). Note that the absorption spectra of C1 to C5 shown in Figure 4 represent the transmission spectra when each absorbing pigment is contained alone (without being mixed with other absorbing pigments) at this content.

[0071] 3 , the transmission spectrum of the filter member according to Example 1 includes a first valley V1, a second valley V2, and a third valley V3 in ranges A1, A2, and A3, respectively, because the filter member includes five types of absorbing dyes C1, C2, C3, C4, and C5. In addition, the transmission spectrum of the filter member according to Example 1 includes a fourth valley V4 due to the transmission spectrum of the substrate 11.

[0072] The first valley V1 is a valley of transmittance formed by the absorber dyes C1 and C4. Therefore, the minimum wavelength λ1 of the first valley V1 is substantially the same as the absorption peak wavelength of the absorber dye C1 or C4. The minimum wavelength λ1 of the first valley V1 is approximately 420 nm. The minimum value of the transmittance of the first valley V1, i.e., the transmittance at the minimum wavelength λ1, is approximately 14%.

[0073] The baseline of the first valley V1 can be considered to be approximately 85%, which is the maximum value of the transmittance of the peak P2. Therefore, the half-width of the first valley V1 is the wavelength width of the first valley V1 when the transmittance is approximately 49% (= (85% + 14%) ÷ 2), and specifically, is approximately 26 nm (= approximately 438 nm - approximately 412 nm).

[0074] The second valley V2 is a transmittance valley formed by the absorber dyes C2 and C5. Therefore, the minimum wavelength λ2 of the second valley V2 is substantially the same as the absorption peak wavelength of the absorber dye C2 or C5. The minimum wavelength λ2 of the second valley V2 is approximately 585 nm. The minimum value of the transmittance of the second valley V2, i.e., the transmittance at the minimum wavelength λ2, is approximately 18%.

[0075] The baseline of the second valley V2 can be considered to be approximately 85%, which is the maximum value of the transmittance of the peak P2. Therefore, the half-width of the second valley V2 is the wavelength width of the second valley V2 when the transmittance is approximately 51% (= (85% + 18%) ÷ 2), and specifically, is approximately 31 nm (= approximately 602 nm - approximately 571 nm).

[0076] The third valley V3 is a transmittance valley formed by the absorber dye C3. Therefore, the minimum wavelength λ3 of the third valley V3 is substantially the same as the absorption peak wavelength of the absorber dye C3. For example, the minimum wavelength λ3 of the third valley V3 is approximately 725 nm. The minimum value of the transmittance of the third valley V3, i.e., the transmittance at the minimum wavelength λ3, is approximately 49%.

[0077] The baseline of the third valley V3 can be considered to be approximately 90%, which is the maximum value of the transmittance of the peak P4. Therefore, the half-width of the third valley V3 is the wavelength width of the third valley V3 when the transmittance is approximately 70% (= (90% + 49%) ÷ 2), and specifically, is approximately 31 nm (= approximately 742 nm - approximately 711 nm).

[0078] The fourth valley V4 is a valley caused by the transmission spectrum of the substrate 11. The transmittance of the fourth valley V4 is approximately 0% at approximately 380 nm. The minimum wavelength λ4 of the fourth valley V4 can be considered to be 380 nm. Note that the fourth valley V4 does not necessarily have to be included in the visible light band.

[0079] The peak wavelength λa of peak P1 is approximately 405 nm. The maximum value of the transmittance of peak P1, i.e., the transmittance at the peak wavelength λa, is approximately 61%. Peak P1 has a transmittance of 50% or more over the entire range from approximately 398 nm to approximately 412 nm. In this embodiment, the peak wavelength λa of peak P1 may be included in range B1.

[0080] In Example 1, the maximum transmittance within range B1 is the transmittance when the wavelength is 400 nm, specifically, approximately 56%. Since the transmittance at the minimum wavelength λ1 (=425 nm) is approximately 14%, the maximum transmittance within range B1 is approximately four times the transmittance at the minimum wavelength λ1.

[0081] The peak wavelength λb of peak P2 is approximately 485 nm. The maximum value of the transmittance of peak P2, i.e., the transmittance at peak wavelength λb, is approximately 85%. Peak P2 has a transmittance of 70% or more over the entire range of approximately 443 nm or more and approximately 528 nm or less. Furthermore, peak P2 has a transmittance of 80% or more over the entire range of approximately 455 nm or more and approximately 515 nm or less. Furthermore, peak P2 has a transmittance of 50% or more over the entire range of approximately 438 nm or more and approximately 570 nm or less.

[0082] In Example 1, the peak wavelength λb of peak P2 is included in range B2. The maximum transmittance within range B2 is the transmittance at the peak wavelength λb (=485 nm), specifically, approximately 85%. Since the transmittance at the minimum wavelength λ2 (=585 nm) is approximately 18%, the maximum transmittance within range B2 is approximately 4.7 times the transmittance at the minimum wavelength λ2.

[0083] The peak wavelength λc of peak P3 is approximately 630 nm. The maximum value of the transmittance of peak P3, i.e., the transmittance at peak wavelength λc, is approximately 84%. Peak P3 has a transmittance of 70% or more over the entire range of approximately 610 nm to approximately 710 nm. Furthermore, peak P3 has a transmittance of 80% or more over the entire range of approximately 618 nm to approximately 700 nm. Furthermore, peak P3 has a transmittance of 60% or more over the entire range of approximately 607 nm to approximately 716 nm.

[0084] In Example 1, the peak wavelength λc of peak P3 is included in range B3. The maximum transmittance within range B3 is the transmittance at peak wavelength λc (=630 nm), specifically, approximately 84%. Since the transmittance at the minimum wavelength λ3 (=725 nm) is approximately 49%, the maximum transmittance within range B3 is approximately 1.7 times the transmittance at the minimum wavelength λ3.

[0085] The peak wavelength λd of peak P4 is approximately 780 nm. The maximum value of the transmittance of peak P4, i.e., the transmittance at the peak wavelength λd, is approximately 90%. Peak P4 has a transmittance of 70% or more over the entire range of approximately 742 nm to approximately 800 nm. Furthermore, peak P4 has a transmittance of 80% or more over the entire range of approximately 747 nm to approximately 800 nm.

[0086] Example 2 A filter member according to Example 2 contains three types of absorbing dyes C6, C7, and C8 as the absorbing dyes 12.

[0087] Figure 5 is a diagram showing the absorption characteristics of three types of absorbing dyes C6, C7, and C8 contained in the filter member of Example 2. In Figure 5, the horizontal axis represents wavelength (unit: nm), and the vertical axis represents transmittance (unit: %). The absorption spectrum shown in Figure 5 is obtained by measuring the transmittance of a transparent substrate (acrylic substrate) in a state where a predetermined amount of absorbing dye is dispersed inside the transparent substrate. Figure 5 shows the transmittance converted assuming that there is no light absorption by the transparent substrate.

[0088] The absorber dyes C6 to C8 are the same type of absorber dyes as the absorber dyes C1 to C3 in Example 1. The peak wavelengths of the absorption peaks of the absorber dyes C6 to C8 are the same as the peak wavelengths of the absorber dyes C1 to C3. The absorber dyes C6 to C8 may have different transmittance values ​​and half-widths at the peak wavelengths from the absorber dyes C1 to C3.

[0089] Specifically, as shown by the thick solid line in Figure 5, the absorption peak wavelength of the absorber dye C6 is approximately 420 nm, and the transmittance at the absorption peak wavelength is approximately 26%. The half-width of the absorption peak (first absorption peak) of the absorber dye C6 is, for example, 50 nm or less, but may be 40 nm or less, 30 nm or less, or 20 nm or less. In the example shown in Figure 5, the baseline of the transmittance for the absorber dye C6 is approximately 100%, and the minimum transmittance is approximately 26%. Therefore, the half-width is the width of the wavelength of the absorption peak when the transmittance is approximately 63%, and is specifically approximately 18 nm (= approximately 429 nm - approximately 411 nm).

[0090] Furthermore, in the absorption spectrum of the absorbing dye C6, at least within the visible light band (range of 380 nm to 780 nm), the transmittance is 95% or more in the range of about 390 nm or less and in the range of about 445 nm or more (excluding the range of about 535 nm to 550 nm). In other words, the absorbing dye C6 does not substantially absorb light in these wavelength ranges.

[0091] As shown by the dashed line in Figure 5, the absorption peak wavelength of the absorber dye C7 is approximately 580 nm, and the transmittance at the absorption peak wavelength is approximately 40%. The half-width of the absorption peak (second absorption peak) of the absorber dye C7 is, for example, 60 nm or less, but may be 50 nm or less, 40 nm or less, 30 nm or less, or 20 nm or less. In the example shown in Figure 5, the baseline transmittance for the absorber dye C7 is approximately 100%, and the minimum transmittance is approximately 40%. Therefore, the half-width is the width of the wavelength of the absorption peak when the transmittance is approximately 70%, and is specifically approximately 23 nm (= approximately 593 nm - approximately 570 nm).

[0092] Furthermore, in the absorption spectrum of the absorbing dye C7, at least within the visible light band (range of 380 nm to 780 nm), the transmittance is 95% or more in the range of approximately 510 nm or less and in the range of approximately 605 nm or more, i.e., the absorbing dye C7 does not substantially absorb light in these wavelength ranges.

[0093] As shown by the dotted line in Figure 5, the absorption peak wavelength of the absorber dye C8 is approximately 715 nm, and the transmittance at the absorption peak wavelength is approximately 34%. The half-width of the absorption peak (third absorption peak) of the absorber dye C8 is, for example, 60 nm or less, but may be 50 nm or less, 40 nm or less, 30 nm or less, or 20 nm or less. In the example shown in Figure 5, the baseline transmittance for the absorber dye C8 is approximately 100%, and the minimum transmittance is approximately 34%. Therefore, the half-width is the width of the wavelength of the absorption peak when the transmittance is approximately 67%, and is specifically approximately 36 nm (= approximately 734 nm - approximately 698 nm).

[0094] Furthermore, in the absorption spectrum of the absorbing dye C8, at least within the visible light band (range of 380 nm to 780 nm), the transmittance is 95% or more in the range of about 610 nm or less and in the range of about 750 nm or more, i.e., the absorbing dye C8 does not substantially absorb light in these wavelength ranges.

[0095] The filter member of Example 2 contains three types of absorbing pigments, C6, C7, and C8, in predetermined ratios. The transmission spectrum of the filter member can be adjusted by adjusting the content of each absorbing pigment. The filter member of Example 2 contains the three types of absorbing pigments, C6, C7, and C8, in a weight ratio of C6:C7:C8=1:3:2. More specifically, the filter member contains 7.5 ppm of absorbing pigment C6, 22.5 ppm of absorbing pigment C7, and 15 ppm of absorbing pigment C8 (designed for a 2 mm thickness). Note that the absorption spectra of C6 to C8 shown in Figure 5 represent the transmission spectra when each absorbing pigment is contained alone (without being mixed with other absorbing pigments) at this content.

[0096] 3 , the transmission spectrum of the filter member according to Example 2 includes a first valley V1, a second valley V2, and a third valley V3 in ranges A1, A2, and A3, respectively, because the filter member includes three types of absorbing dyes C6, C7, and C8. In addition, the transmission spectrum of the filter member according to Example 2 includes a fourth valley V4 due to the transmission spectrum of the substrate 11.

[0097] The first valley V1 is a valley in transmittance formed by the absorber dye C6. Therefore, the minimum wavelength λ1 of the first valley V1 is substantially the same as the absorption peak wavelength of the absorber dye C6. The minimum wavelength λ1 of the first valley V1 is approximately 420 nm. The minimum value of the transmittance of the first valley V1, i.e., the transmittance at the minimum wavelength λ1, is approximately 20%.

[0098] The baseline of the first valley V1 can be considered to be approximately 85%, which is the maximum value of the transmittance of the peak P2. Therefore, the half-width of the first valley V1 is the wavelength width of the first valley V1 when the transmittance is approximately 53% (= (85% + 20%) ÷ 2), and specifically, is approximately 21 nm (= approximately 433 nm - approximately 411 nm).

[0099] The second valley V2 is a transmittance valley formed by the absorber dye C7. Therefore, the minimum wavelength λ2 of the second valley V2 is substantially the same as the absorption peak wavelength of the absorber dye C7. The minimum wavelength λ2 of the second valley V2 is approximately 585 nm. The minimum value of the transmittance of the second valley V2, i.e., the transmittance at the minimum wavelength λ2, is approximately 28%.

[0100] The baseline of the second valley V2 can be considered to be approximately 85%, which is the maximum value of the transmittance of the peak P2. Therefore, the half-width of the second valley V2 is the wavelength width of the second valley V2 when the transmittance is approximately 57% (= (85% + 28%) ÷ 2), and specifically, is approximately 23 nm (= approximately 594 nm - approximately 571 nm).

[0101] The third valley V3 is a transmittance valley formed by the absorber dye C8. Therefore, the minimum wavelength λ3 of the third valley V3 is substantially the same as the absorption peak wavelength of the absorber dye C8. For example, the minimum wavelength λ3 of the third valley V3 is approximately 725 nm. The minimum value of the transmittance of the third valley V3, i.e., the transmittance at the minimum wavelength λ3, is approximately 31%.

[0102] The baseline of the third valley V3 can be considered to be approximately 90%, which is the maximum value of the transmittance of the peak P4. Therefore, the half-width of the third valley V3 is the wavelength width of the third valley V3 when the transmittance is approximately 61% (= (90% + 31%) ÷ 2), and specifically, is approximately 34 nm (= approximately 743 nm - approximately 709 nm).

[0103] The fourth valley V4 is a valley caused by the transmission spectrum of the substrate 11. The transmittance of the fourth valley V4 is approximately 0% at approximately 380 nm. The minimum wavelength λ4 of the fourth valley V4 can be considered to be 380 nm. Note that the fourth valley V4 does not necessarily have to be included in the visible light band.

[0104] The peak wavelength λa of peak P1 is approximately 405 nm. The maximum value of the transmittance of peak P1, i.e., the transmittance at the peak wavelength λa, is approximately 65%. Peak P1 has a transmittance of 50% or more over the entire range from approximately 398 nm to approximately 412 nm. In this embodiment, the peak wavelength λa of peak P1 may be included in range B1.

[0105] In Example 2, the maximum transmittance within range B1 is the transmittance when the wavelength is 400 nm, specifically, approximately 58%. Since the transmittance at the minimum wavelength λ1 (=425 nm) is approximately 20%, the maximum transmittance within range B1 is approximately 2.9 times the transmittance at the minimum wavelength λ1.

[0106] The peak wavelength λb of peak P2 is approximately 490 nm. The maximum value of the transmittance of peak P2, i.e., the transmittance at peak wavelength λb, is approximately 85%. Peak P2 has a transmittance of 70% or more over the entire range of approximately 438 nm or more and approximately 532 nm or less. Furthermore, peak P2 has a transmittance of 80% or more over the entire range of approximately 454 nm or more and approximately 521 nm or less. Furthermore, peak P2 has a transmittance of 50% or more over the entire range of approximately 433 nm or more and approximately 573 nm or less.

[0107] In Example 2, the peak wavelength λb of peak P2 is included in range B2. The maximum transmittance within range B2 is the transmittance at peak wavelength λb (=490 nm), specifically, approximately 85%. Since the transmittance at the minimum wavelength λ2 (=585 nm) is approximately 28%, the maximum transmittance within range B2 is approximately three times the transmittance at the minimum wavelength λ2.

[0108] The peak wavelength λc of peak P3 is approximately 620 nm. The maximum value of the transmittance of peak P3, i.e., the transmittance at peak wavelength λc, is approximately 84%. Peak P3 has a transmittance of 70% or more over the entire range of approximately 598 nm to approximately 702 nm. Furthermore, peak P3 has a transmittance of 80% or more over the entire range of approximately 606 nm to approximately 637 nm. Furthermore, peak P3 has a transmittance of 60% or more over the entire range of approximately 597 nm to approximately 709 nm.

[0109] In Example 2, the peak wavelength λc of peak P3 is included in range B3. The maximum transmittance within range B3 is the transmittance at peak wavelength λc (=620 nm), specifically, approximately 84%. Since the transmittance at the minimum wavelength λ3 (=725 nm) is approximately 31%, the maximum transmittance within range B3 is approximately 2.7 times the transmittance at the minimum wavelength λ3.

[0110] The peak wavelength λd of peak P4 is approximately 780 nm. The maximum value of the transmittance of peak P4, i.e., the transmittance at the peak wavelength λd, is approximately 90%. Peak P4 has a transmittance of 70% or more over the entire range of approximately 747 nm to approximately 800 nm. Furthermore, peak P4 has a transmittance of 80% or more over the entire range of approximately 752 nm to approximately 800 nm.

[0111] [Functions and Effects of Filter Member] Next, the functions and effects of the filter members according to Examples 1 and 2 will be described.

[0112] <Display Appearance> First, the appearance of a typical display 110 will be described with reference to Figures 6A and 6B. Figure 6A is a diagram showing the emission spectrum of the display 110. In Figure 6A, the horizontal axis represents wavelength (unit: nm), and the vertical axis represents light intensity (unit: a.u.).

[0113] 6A, the display 110 emits light having peaks in three colors (three wavelengths): red (R: approximately 590 nm), green (G: approximately 520 nm), and blue (B: approximately 440 nm). The display 110 is able to display white as a mixture of the three colors. In this case, the color gamut tends to be narrowed due to partial overlap of the wavelength components of the red light and the green light.

[0114] In contrast, by viewing the display 110 through the filter member according to this embodiment, it is possible to improve the color separation of the red, green, and blue light emitted by the display 110. Specifically, it is possible to widen the color gamut of the display 110, improving the visibility of the display 110. This is because the filter member has the transmission spectrum shown in FIG.

[0115] Fig. 6B is an xy chromaticity diagram for explaining the difference in color gamut of the display 110 depending on whether or not the filter member according to Examples 1 and 2 is present. Fig. 6B shows a chromaticity diagram (CIE 1931) in the xy color system defined by the CIE (International Commission on Illumination).

[0116] In Figure 6B, a triangle with three plots marked with triangles as its vertices represents the color gamut of the emitted color of the display 110. A triangle with three plots marked with squares as its vertices represents the color gamut of the display 110 when viewed through the filter member (lens 10) according to Example 1. A triangle with three plots marked with circles as its vertices represents the color gamut of the display 110 when viewed through the filter member (lens 10) according to Example 2. The plots at each vertex of the triangle correspond to the RGB of the display 110, respectively. The size (area) of the triangle corresponds to the width of the color gamut.

[0117] As shown in Figure 6B, when viewed through the filter member according to Example 1 or 2, it can be seen that the color gamut of the display 110 is expanded. The color gamut expands toward the green side (near 550 nm) and the red side (near 610 nm). If the color gamut of the display 110 alone is considered to be 100%, the color gamut for the filter member according to Example 1 is approximately 115%. The color gamut for the filter member according to Example 2 is approximately 109%.

[0118] In this way, it is possible to improve the visibility of the display 110 when the display 110 is viewed through the filter member (lens 10). Specifically, it is possible to widen the color gamut of the display 110.

[0119] <Appearance of Objects Other Than the Display> Next, a description will be given of how an object other than the display 110 appears. First, how an object appears in a sunlight irradiation environment will be described with reference to Figs. 7A and 7B.

[0120] FIG. 7A is a diagram showing the spectrum of sunlight. In FIG. 7A, the horizontal axis represents wavelength (unit: nm), and the vertical axis represents light intensity (unit: a.u.). As shown in FIG. 7A, sunlight has high intensity overall in the visible light band (380 nm or more and 780 nm or less). In the example shown in FIG. 7A, the conspicuity index (FCI) of sunlight is 104. The color temperature of sunlight is 5575 K. The chroma value of sunlight is 1.34. The color temperature, FCI, and chroma value are calculated using known techniques based on the emission spectrum.

[0121] Fig. 7B is a diagram showing the spectrum of transmitted light of sunlight that has passed through the filter members according to Examples 1 and 2. In Fig. 7B, the horizontal axis represents wavelength (unit: nm) and the vertical axis represents light intensity (unit: a.u.). Fig. 7B shows the spectrum of transmitted light of sunlight having the spectrum shown in Fig. 7A.

[0122] As shown in Figure 7B, sunlight passes through the filter member and is absorbed by the absorbing pigment contained in the filter member. As a result, three large transmittance valleys caused by the absorbing pigment are formed in the spectrum of the transmitted light that has passed through the filter member. As a result, as shown in Table 1, the conspicuity index FCI, color temperature, and chroma value of the transmitted light that has passed through the filter of Example 1 are 120, 6700 K, and 1.18, respectively. The conspicuity index FCI, color temperature, and chroma value of the transmitted light that has passed through the filter of Example 2 are 114, 6251 K, and 1.06, respectively.

[0123]

[0124] In this way, the conspicuity index FCI of the transmitted light when sunlight passes through the filter member is higher than the conspicuity index FCI of the sunlight before passing through the filter member, thereby increasing the vividness of the object color. Furthermore, the color temperature of the transmitted light is higher than the color temperature of sunlight. This enhances the perceived whiteness of a white object when viewed in a sunlight-irradiated environment. Specifically, the chroma value of the transmitted light is lower than the chroma value of sunlight, confirming that the perceived whiteness of the white object is enhanced.

[0125] Next, how an object appears in an illumination environment using a general illumination device (illumination device 120 shown in FIG. 2) will be described with reference to FIGS. 8A and 8B. FIG.

[0126] FIG. 8A is a diagram showing the spectrum of white light from a white LED. In FIG. 8A, the horizontal axis represents wavelength (unit: nm), and the vertical axis represents light intensity (unit: a.u.). As shown in FIG. 8A, white light from a typical white LED (hereinafter simply referred to as white light) has a peak in emission intensity in the blue (near 460 nm) and a gentle peak with a large half-width from green to red. In the example shown in FIG. 8A, the conspicuity index (FCI) of the white light is 97. The color temperature of the white light is 5154 K. The chroma value of the white light is 1.37.

[0127] Fig. 8B is a diagram showing the spectrum of transmitted light of white light that has passed through the filter members according to Examples 1 and 2. In Fig. 8B, the horizontal axis represents wavelength (unit: nm) and the vertical axis represents light intensity (unit: a.u.). Fig. 8B shows the spectrum of transmitted light of sunlight having the spectrum shown in Fig. 8A.

[0128] As shown in Figure 8B, when white light passes through the filter member, it is absorbed by the absorbing pigment contained in the filter member. As a result, three large transmittance valleys caused by the absorbing pigment are formed in the spectrum of the transmitted light that has passed through the filter member. As a result, as shown in Table 2, the conspicuity index FCI, color temperature, and chroma value of the transmitted light that has passed through the filter of Example 1 are 116, 6900 K, and 1.04, respectively. The conspicuity index FCI, color temperature, and chroma value of the transmitted light that has passed through the filter of Example 2 are 111, 6070 K, and 0.52, respectively.

[0129]

[0130] In this way, when white light from a white LED is passed through the filter member, the conspicuity index FCI of the transmitted light is higher than the conspicuity index FCI of the white light before passing through the filter member, thereby increasing the vividness of the object color. Furthermore, the color temperature of the transmitted light is higher than the color temperature of the white light. This enhances the perceived whiteness of a white object when viewed in an environment illuminated by white light from a white LED. Specifically, the chroma value of the transmitted light is lower than the chroma value of the white light, confirming that the perceived whiteness of the white object is enhanced.

[0131] Table 3 shows the conspicuity index FCI, color temperature, and chroma value of transmitted light when equal-energy white light is passed through the filter members according to Examples 1 and 2. Equal-energy white light is white light in which the energy of each wavelength in the visible light band is equal. The conspicuity index FCI of the equal-energy white light is 108. The color temperature of the equal-energy white light is 5456 K. The chroma value of the equal-energy white light is 1.13.

[0132]

[0133] As shown in Table 3, the conspicuity index FCI, color temperature, and chroma value of the transmitted light passing through the filter according to Example 1 are 125, 6700 K, and 1.18, respectively. The conspicuity index FCI, color temperature, and chroma value of the transmitted light passing through the filter according to Example 2 are 119, 6007 K, and 0.62, respectively.

[0134] In this way, when equal-energy white light is passed through the filter member, the conspicuity index FCI of the transmitted light is higher than the conspicuity index FCI of the equal-energy white light before passing through the filter member, thereby increasing the vividness of the object color. Specifically, the conspicuity index FCI of the transmitted light is 110 or higher. Furthermore, the color temperature of the transmitted light is higher than the color temperature of the white light. Specifically, the color temperature of the transmitted light is 6200 K or higher. This enhances the perceived whiteness of a white object when viewed in an environment illuminated with equal-energy white light. Specifically, the chroma value of the transmitted light is lower than the chroma value of the equal-energy white light, confirming that the perceived whiteness of the white object is enhanced.

[0135] [Modification] Next, a modification of the lens 10 according to the embodiment described above will be described. In the embodiment described above, the entire lens 10 is a filter member. In contrast, in the lens according to this modification, the filter member is provided only in a portion. The following description will focus on the differences from the embodiment, and description of the commonalities will be omitted or simplified.

[0136] Fig. 9 is a perspective view of the appearance of a lens 20 equipped with a filter member according to this modification, and eyeglasses 2 equipped with the lens 20. As shown in Fig. 9, the lens 20 includes a first region 21 in which the filter member is provided, and a second region 22 in which the filter member is not provided.

[0137] When the lens 20 is viewed from the front, the area of ​​the filter member, i.e., the area of ​​the first region 21, is equal to or greater than half the area of ​​the lens 20. The area of ​​the first region 21 is equal to or greater than the area of ​​the second region 22. In the example shown in Fig. 9, the first region 21 is provided above the second region 22, but this is not limiting. The first region 21 may be located in the center of the lens 20 and surrounded by the second region 22.

[0138] [Summary] A filter member according to a first aspect of the present invention is a filter member provided in a member worn by a user U, and includes a substrate 11 and one or more types of absorbing dyes 12 dispersed in the substrate 11. The transmission spectrum of the filter member has a first valley V1 where a first minimum wavelength λ1 is located in the range of 400 nm to 450 nm, a second valley V2 where a second minimum wavelength λ2 is located in the range of 540 nm to 600 nm, and a third valley V3 where a third minimum wavelength λ3 is located in the range of 680 nm to 800 nm. The maximum transmittance of the filter member in the range of 350 nm to 400 nm is 2.5 times or more the transmittance of the filter member at the first minimum wavelength λ1. The maximum transmittance of the filter member in the range of 450 nm to 540 nm is 3 times or more the transmittance of the filter member at the second minimum wavelength λ2. The maximum value of the transmittance of the filter member within the range of 600 nm to 680 nm is 1.6 times or more the transmittance of the filter member at the third minimum wavelength λ3.

[0139] This improves the visibility of both the display 110 and the object (e.g., the foliage plant 130). Specifically, the color gamut of the display 110 can be widened, and the perceived whiteness of the object can be enhanced.

[0140] A filter member according to a second aspect of the present invention is a filter member according to the first aspect, wherein the maximum transmittance of the filter member in the range of 350 nm or more and 400 nm or less is 50% or more, the maximum transmittance of the filter member in the range of 450 nm or more and 540 nm or less is 70% or more, and the maximum transmittance of the filter member in the range of 600 nm or more and 680 nm or less is 70% or more.

[0141] This allows light corresponding to RGB to pass through with high transmittance, thereby preventing the display 110 and objects from becoming difficult to see due to insufficient light.

[0142] A filter member according to a third aspect of the present invention is the filter member according to the first or second aspect, wherein the luminous transmittance of the filter member is 60% or more.

[0143] This provides high transmittance in the visible light range, improving the visibility of both the display 110 and objects.

[0144] A filter member according to a fourth aspect of the present invention is a filter member according to any one of the first to third aspects, wherein the transmittance of the filter member at the first minimal wavelength λ1 is 10% or more and 20% or less, the transmittance of the filter member at the second minimal wavelength λ2 is 10% or more and 30% or less, and the transmittance of the filter member at the third minimal wavelength λ3 is 30% or more and 60% or less.

[0145] This allows wavelength components whose transmission should be suppressed to be sufficiently suppressed. For example, it is possible to suppress transmission of overlapping portions of red light and green light from the display 110, thereby widening the color gamut of the display 110.

[0146] A filter member according to a fifth aspect of the present invention is a filter member according to any one of the first to fourth aspects, wherein the noticeable index FCI of the transmitted light when equal-energy white light is passed through the filter member is 110 or more.

[0147] This increases the noticeable index FCI of transmitted light, thereby improving color reproducibility and increasing the vividness of the colors of objects.

[0148] A filter member according to a sixth aspect of the present invention is a filter member according to any one of the first to fifth aspects, wherein when equal-energy white light is passed through the filter member, the color temperature of the transmitted light is 6200 K or higher.

[0149] This increases the color temperature of the transmitted light, thereby enhancing the perceived whiteness of a white object.

[0150] A filter member according to a seventh aspect of the present invention is the filter member according to any one of the first to sixth aspects, wherein the substrate 11 is a resin substrate.

[0151] This allows the absorbing dye 12 to be easily mixed into the substrate 11. Furthermore, since a material with excellent transparency can be used as the resin substrate, the transmittance of the filter member according to this embodiment can be increased. Furthermore, since molding is easy, the filter member according to this embodiment can be easily formed into a desired shape.

[0152] A lens according to an eighth aspect of the present invention is, for example, the above-described lens 10 or 20, and is a lens for eyeglasses that includes a filter member according to any one of the first to seventh aspects. The lens according to this aspect may be a lens for sunglasses or a lens for goggles.

[0153] As a result, the eyeglasses, sunglasses, or goggles including the lenses 10 or 20 can be worn on the head of the user U, freeing both hands. Since both hands are free, work efficiency can be improved in the work system 100.

[0154] A lens according to a ninth aspect of the present invention is the lens according to the eighth aspect, wherein when the lens is viewed from the front, the area of ​​the filter member is equal to or greater than half the area of ​​the lens.

[0155] This allows the filter member to be provided only in the necessary area of ​​the lens, making it possible to selectively view an object through the filter member and without the filter member.

[0156] (Others) Although the filter member and lens according to the present invention have been described above based on the above-mentioned embodiment, the present invention is not limited to the above-mentioned embodiment.

[0157] For example, the transmission spectrum of the filter member shown in FIG. 3 is merely an example. The transmission spectrum may be adjusted as follows, as long as the object of the present disclosure can be achieved. For example, the maximum transmittance of the filter member within range B1 may be less than 50%. The maximum transmittance of the filter member within range B2 may be less than 70%. The maximum transmittance of the filter member within range B3 may be less than 70%. The luminous transmittance of the filter member may be less than 60%. The transmittance of the filter member at the first minimum wavelength λ1 may be less than 10% or may be 20% or more. The transmittance of the filter member at the second minimum wavelength λ2 may be less than 10% or may be 30% or more. The transmittance of the filter member at the third minimum wavelength λ3 may be less than 30% or may be less than 60%.

[0158] Furthermore, for example, in the above-described embodiments, the transmission spectrum of the filter member is configured using five or three types of absorbing dyes, but this is not limited thereto. For example, the filter member may contain only one type of absorbing dye, only two types of absorbing dyes, or only four types of absorbing dyes. Alternatively, the filter member may contain six or more types of absorbing dyes.

[0159] Although the substrate 11 is a resin substrate in the above example, the substrate 11 is not limited to this. The substrate 11 may be a glass substrate, a quartz substrate, or the like.

[0160] Furthermore, for example, the filter member may be used for contact lenses. The present invention may be glasses, sunglasses, or goggles that include a filter member, or may be contact lenses that include a filter member.

[0161] In addition, the present invention also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art would think of, and forms realized by arbitrarily combining the components and functions of each embodiment within the scope of the present invention.

[0162] 1, 2 Glasses 10, 20 Lens 11 Substrate 12 Absorbing dye 110 Display

Claims

1. A filter member provided in an item worn by a user, the filter member comprising: a substrate; and one or more types of absorbing dyes dispersed in the substrate; a transmission spectrum of the filter member having a first valley in which a first minimum wavelength is located in a range of 400 nm to 450 nm, a second valley in which a second minimum wavelength is located in a range of 540 nm to 600 nm, and a third valley in which a third minimum wavelength is located in a range of 680 nm to 800 nm, the maximum value of the transmittance of the filter member in the range of 350 nm to 400 nm being 2.5 times or more the transmittance of the filter member at the first minimum wavelength, and the maximum value of the transmittance of the filter member in the range of 450 nm to 540 nm being 3 times or more the transmittance of the filter member at the second minimum wavelength, A filter member, wherein a maximum transmittance of the filter member within a range of 600 nm to 680 nm is 1.6 times or more a transmittance of the filter member at the third minimum wavelength.

2. A filter member as described in claim 1, wherein the maximum transmittance of the filter member in the range of 350 nm or more and 400 nm or less is 50% or more, the maximum transmittance of the filter member in the range of 450 nm or more and 540 nm or less is 70% or more, and the maximum transmittance of the filter member in the range of 600 nm or more and 680 nm or less is 70% or more.

3. The filter member according to claim 1, wherein the filter member has a luminous transmittance of 60% or more.

4. A filter member according to any one of claims 1 to 3, wherein the transmittance of the filter member at the first minimal wavelength is 10% or more and 20% or less, the transmittance of the filter member at the second minimal wavelength is 10% or more and 30% or less, and the transmittance of the filter member at the third minimal wavelength is 30% or more and 60% or less.

5. The filter member according to any one of claims 1 to 3, wherein a feeling of contrast index (FCI) of transmitted light when equal-energy white light is passed through the filter member is 110 or more.

6. A filter member according to any one of claims 1 to 3, wherein when equal-energy white light is passed through the filter member, the color temperature of the transmitted light is 6200K or higher.

7. The filter member according to any one of claims 1 to 3, wherein the substrate is a resin substrate.

8. A lens for spectacles, sunglasses or goggles, comprising the filter member according to any one of claims 1 to 3.

9. The lens according to claim 8, wherein when the lens is viewed from the front, the area of ​​the filter member is equal to or greater than half the area of ​​the lens.

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