JP2014071166A - Optical member, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical member that prevents light reflection from causing glaring and displays a character or pattern.SOLUTION: The optical member 1 includes a low reflection region 11a of a relatively low reflectance and a high reflection region 11b of a relatively high reflectance. A character or pattern 11 is formed of the low reflection region 11a and high reflection region 11b. The low reflection region 11a includes an antireflection film 10.

Description

  The present invention relates to an optical member and a manufacturing method thereof.

  Conventionally, an attempt has been made to form an antireflection film on the surface of an optical member to suppress reflection of a background or the like due to light reflection (see, for example, Patent Document 1).

JP 2007-025078 A

  For example, when an optical member is used as a showcase, a window plate, a partition, or the like, there is a demand to suppress reflection due to light reflection and to display symbols such as characters and symbols.

  A main object of the present invention is to provide an optical member that is unlikely to be reflected by light reflection and that displays characters or designs.

  The optical member according to the present invention includes a low reflection region having a relatively low reflectance and a high reflection region having a relatively high reflectance. A character or a pattern is constituted by the low reflection region and the high reflection region. The low reflection region has an antireflection film.

  The area of the low reflection region is preferably larger than the area of the high reflection region.

  The difference between the luminous reflectance in the low reflection area and the luminous reflectance in the high reflection area is preferably 5% or more.

  The antireflection film is preferably formed by alternately laminating a low refractive index layer having a relatively low refractive index and a high refractive index layer having a relatively high refractive index.

  The outermost layer of the antireflection film may be composed of a low refractive index layer, and the refractive index of the outermost layer in the high reflection region may be higher than the refractive index of the low refractive index layer.

  A film having the same layer configuration as at least a part of the antireflection film may be provided in the high reflection region.

  Each outermost layer of the low reflection region and the high reflection region may be constituted by a low refractive index layer.

  The thickness of the low refractive index layer constituting the outermost layer of the low reflection region is different from the thickness of the low refractive index layer constituting the outermost layer of the high reflection region. The film configuration of the portion excluding the low refractive index layer may be the same as the film configuration of the portion excluding the low refractive index layer constituting the outermost layer of the high reflection region.

  The thickness of the film provided in the high reflection region may be smaller than the thickness of the film provided in the low reflection region.

  The difference between the thickness of the film provided in the high reflection region and the thickness of the film provided in the low reflection region is preferably 420 nm or less.

  The film provided in the high reflection region is preferably formed by removing a part of the layer on the surface side of the antireflection film.

  In the first method for producing an optical member according to the present invention, an antireflection film is formed on a substrate. By etching a part of the antireflection film, a part along the thickness direction of the part is removed, and a character or a pattern is constituted by an etched part and an unetched part of the antireflection film. .

  In the second method for producing an optical member according to the present invention, an antireflection film is formed on the substrate. A layer having a refractive index higher than the refractive index of the surface of the antireflection film is formed on a part of the antireflection film.

  In each of the first and second optical member manufacturing methods according to the present invention, a low refractive index layer having a relatively low refractive index and a high refractive index layer having a relatively high refractive index are alternately laminated. Thus, it is preferable to form an antireflection film.

  According to the present invention, it is possible to provide an optical member that is unlikely to be reflected by light reflection and that displays characters or designs.

It is a schematic sectional drawing for demonstrating the manufacturing method of the optical member in 1st Embodiment. It is a schematic sectional drawing of the optical member in 1st Embodiment. It is a schematic sectional drawing of the optical member in a 1st modification. It is a schematic sectional drawing of the optical member in a 2nd modification. It is a schematic sectional drawing of the optical member in 2nd Embodiment.

  Hereinafter, an example of the preferable form which implemented this invention is demonstrated. However, the following embodiment is merely an example. The present invention is not limited to the following embodiments.

  Moreover, in each drawing referred in embodiment etc., the member which has a substantially the same function shall be referred with the same code | symbol. The drawings referred to in the embodiments and the like are schematically described. A ratio of dimensions of an object drawn in a drawing may be different from a ratio of dimensions of an actual object. The dimensional ratio of the object may be different between the drawings. The specific dimensional ratio of the object should be determined in consideration of the following description.

(First embodiment)
FIG. 1 is a schematic cross-sectional view for explaining a method for manufacturing an optical member in the first embodiment. FIG. 2 is a schematic cross-sectional view of the optical member in the first embodiment.

In the present embodiment, an example of manufacturing the optical member 1 shown in FIG. 2 will be described. First, as shown in FIG. 1, a base material 20 on which an antireflection film 10 is formed is prepared. The base material 20 may be made of, for example, a glass material, a resin material, a ceramic material, or the like. The substrate 20 may be, for example, a plate shape, a lens shape, a prism shape, or the like. The base material 20 may have translucency or may not have translucency.

  The antireflection film 10 is a film for reducing the reflectance on the surface of the optical member 1. The luminous reflectance of the antireflection film 10 is preferably 4% or less, more preferably 1% or less, and further preferably 0.1% or less.

  The “luminous reflectance” is the tristimulus value Y in the XYZ color system, and the luminous reflectance is measured by measuring the visible light reflectance in the wavelength range of 380 nm to 780 nm at an incident angle of 5 °. It can be calculated from the measured visible light reflectance, the spectral distribution of illumination (D65), and the color matching function (CIE1964).

  The antireflection film 10 may be formed of, for example, a multilayer film in which low refractive index layers 10L and high refractive index layers 10H are alternately stacked. In that case, from the viewpoint of reducing the reflectance on the surface of the antireflection film 10, it is preferable that the surface of the antireflection film 10 is composed of the low refractive index layer 10L.

  The low refractive index layer 10L has a relatively low refractive index, and the high refractive index layer 10H has a relatively high refractive index. That is, the refractive index of the high refractive index layer 10H is higher than the refractive index of the low refractive index layer 10L. The refractive index of the high refractive index layer 10H is usually 0.5 to 1 higher than the refractive index of the low refractive index layer 10L.

  The low refractive index layer 10L can be made of, for example, silicon oxide, magnesium fluoride, or the like.

  The high refractive index layer 10H can be composed of a metal oxide such as niobium oxide, titanium oxide, tantalum oxide, zirconium oxide, yttrium oxide, hafnium oxide, tungsten oxide, or bismuth oxide.

  The total number of films of the low refractive index layer 10L and the high refractive index layer 10H constituting the antireflection film 10 can be, for example, about 2 to 20.

  Next, as shown in FIG. 2, a part of the antireflection film 10 is etched to remove a part along the thickness direction (etching process). By this etching step, the non-etched antireflection film 10 remains, and the remaining antireflection film 10 forms a low reflection region 11a having a relatively low reflectance. Further, a part of the layer on the surface side of the antireflection film 10 is removed by an etching process, and the high reflection region 11b having a relatively high reflectance is formed. The optical member 1 which comprises the character or the pattern 11 by the low reflection area | region 11a and the high reflection area | region 11b is obtained. The thickness of the film provided in the high reflection region 11b is thinner than the thickness of the film provided in the low reflection region 11a. The low reflection region 11 a has a layer configuration that is substantially the same as a portion excluding at least a part of the layer on the surface side of the antireflection film 10.

  As described above, in the optical member 1, since the low reflection region 11 a is formed by the remaining portion of the antireflection film 10, the reflection due to the light reflection hardly occurs even though the character or the pattern 11 is displayed. .

From the viewpoint of making reflection due to light reflection more difficult, the area of the low reflection region 11a is preferably larger than the area of the high reflection region 11b, and is 1.5 times or more the area of the high reflection region 11b. Is more preferably 2 times or more, still more preferably 3 times or more.

  The antireflection film 10 can be etched using, for example, an etching agent. Specifically, it may be immersed in an etching solution in a state where a mask is disposed on the antireflection film 10 so that a portion to be etched is exposed. Further, an etching paste may be applied on the portion of the antireflection film 10 to be etched.

  In order to display the character or the pattern 11 clearly, it is preferable that the difference between the luminous reflectance of the low reflection region 11a and the luminous reflectance of the high reflection region 11b is 5% or more. % Or more is more preferable. The luminous reflectance of the low reflection region 11a is preferably 4% or less, and more preferably 0.2% or less. The luminous reflectance of the high reflection region 11b is preferably 5% or more, and more preferably 10% or more.

  From the viewpoint of increasing the luminous reflectance in the high reflection region 11b, for example, the low refractive index layer 10L1 (see FIG. 1) constituting the outermost layer of a part of the antireflection film 10 is removed to achieve high refraction. The rate layer 10H1 may be exposed. That is, the outermost layer of the low reflection region 11a is the low refractive index layer 10L, and the outermost layer of the high reflection region 11b is set so that the refractive index of the uppermost layer of the high reflection region 11b is higher than the refractive index of the low refractive index layer 10L. You may comprise by the high refractive index layer 10H.

  When the antireflection film 10 in which the low refractive index layers 10L and the high refractive index layers 10H are alternately stacked is employed as in the present embodiment, the refractive index change when etching is large. That is, even when the thickness of the portion removed by etching is small, the refractive index can change greatly. Therefore, the difference in reflectance between the low reflection region 11a and the high reflection region 11b can be increased with a small etching amount, and the characters or symbols 11 can be clearly displayed.

  The number of layers removed by etching the antireflection film 10 is preferably 9 layers or less, more preferably 7 layers or less, further preferably 5 layers or less, and preferably 1 layer or less. Further preferred. By reducing the number of layers removed by etching the antireflection film 10, it is possible to suppress blurring of the outline of the characters or the pattern 11 due to the penetration of the etchant between the layers. Further, since the difference between the thickness of the film provided in the low reflection region 11a and the thickness of the film provided in the high reflection region 11b can be reduced, peeling of a portion protruding from the high reflection region 11b of the low reflection region 11a, etc. Can be suppressed. From this viewpoint, the difference between the thickness of the film provided in the low reflection region 11a and the thickness of the film provided in the high reflection region 11b is preferably 420 nm or less, more preferably 300 nm or less, and 90 nm. More preferably, it is as follows.

  In the present embodiment, an example in which only the low refractive index layer 10L1 constituting the outermost layer of a part of the antireflection film 10 is removed by etching has been described. However, the present invention is not limited to this configuration. For example, as shown in FIG. 3, a plurality of layers on the surface side of a part of the antireflection film 10 may be removed by etching. Even in this case, the low reflection region 11a having a relatively low reflectance and the high reflection region 11b having a relatively high reflectance can be suitably formed.

  When a plurality of layers on the surface side of a part of the antireflection film 10 are removed by etching, the outermost layers of the low reflection region 11a and the high reflection region 11b may be etched so as to be constituted by the low refractive index layer 10L. Good. Here, the low refractive index layer 10L is generally superior in weather resistance than the high refractive index layer 10H. Therefore, it is possible to obtain a character or pattern 11 having excellent weather resistance.

Further, as shown in FIG. 4, only a part of the antireflection film 10 in the thickness direction of the low refractive index layer 10L1 constituting the outermost layer may be removed by etching. In this case, both surfaces of the low reflection region 11a and the high reflection region 11b are constituted by the low refractive index layer 10L. Therefore, excellent weather resistance can be realized, and reflection of the background or the like can be more effectively suppressed. The thickness of the low refractive index layer 10L constituting the outermost layer of the low reflection region 11a is different from the thickness of the low refractive index layer 10L constituting the outermost layer of the high reflection region 11b. The thickness of the low refractive index layer 10L constituting the outermost layer of the low reflection region 11a is thicker than the thickness of the low refractive index layer 10L constituting the outermost layer of the high reflection region 11b. The film configuration of the portion excluding the low refractive index layer 10L constituting the outermost layer of the low reflection region 11a and the film configuration of the portion excluding the low refractive index layer 10L constituting the outermost layer of the high reflection region 11b Is equal to

  Hereinafter, other examples of preferred embodiments of the present invention will be described. In the following description, members having substantially the same functions as those of the first embodiment are referred to by the same reference numerals, and description thereof is omitted.

(Second Embodiment)
As shown in FIG. 5, in the present embodiment, unlike the first embodiment, the antireflection film 10 is not etched. Instead, a layer 12 having a refractive index higher than the refractive index of the low refractive index layer 10L on the surface of the antireflection film 10 is formed on a part of the antireflection film 10. A highly reflective region 11 b is formed from a laminate of the layer 12 and the antireflection film 10. The low reflection region 11a is configured by a region that is formed of only the antireflection film 10 without the layer 12. Even in this case, it is possible to display characters or symbols 11 as in the first embodiment. The refractive index of the layer 12 is preferably 0.5 or more higher than the refractive index of the surface of the antireflection film 10, and more preferably 1 or higher.

  In the present embodiment, in forming the character or design 11, the area of the low reflection region 11a is preferably larger than the area of the high reflection region 11b, and is 1.5 times or more the area of the high reflection region 11b. More preferably, it is more preferably 2 times or more. By doing in this way, reflection of a background etc. can be suppressed more effectively.

  Hereinafter, the present invention will be described in more detail on the basis of specific examples. However, the present invention is not limited to the following examples, and may be appropriately modified and implemented without departing from the scope of the present invention. Is possible.

Example 1
The antireflection film 10 having a 16-layer structure as shown in Table 1 is formed, and a part of the silicon oxide layer constituting the outermost layer of the antireflection film 10 is removed by etching. An optical member having the region 11b was produced. The luminous reflectance of the low reflective area 11a was 0.13%, whereas the luminous reflectance of the high reflective area 11b was 12.1%. When light was incident from a direction inclined by 5 ° with respect to the normal to the surface of the optical member, a pattern composed of the low reflection region 11a and the high reflection region 11b was visually recognized from the surface of the optical member.

(Example 2)
In addition to the silicon oxide layer (16th layer) constituting the outermost surface layer of the antireflection film 10, a part of the niobium oxide layer (15th layer) adjacent thereto is removed by etching to form a highly reflective region 11b. An optical member was produced in the same manner as in Example 1 except that. Table 2 shows the layer structure in this example. The luminous reflectance of the low reflective area 11a was 0.13%, whereas the luminous reflectance of the high reflective area 11b was 16.9%. When light was incident from a direction inclined by 5 ° with respect to the normal to the surface of the optical member, a pattern composed of the low reflection region 11a and the high reflection region 11b was visually recognized from the surface of the optical member.

(Example 3)
An optical member was fabricated in the same manner as in Example 1 except that the high reflection region 11b was formed by removing a part of the 16th to 11th layers of the antireflection film 10 by etching. Table 3 shows the layer structure in this example. The luminous reflectance of the low reflective area 11a was 0.13%, whereas the luminous reflectance of the high reflective area 11b was 11.2%. When light was incident from a direction inclined by 5 ° with respect to the normal to the surface of the optical member, a pattern composed of the low reflection region 11a and the high reflection region 11b was visually recognized from the surface of the optical member.

Example 4
An optical member was fabricated in the same manner as in Example 1 except that the high reflection region 11b was formed by removing a part of the 16th to 10th layers of the antireflection film 10 by etching. Table 4 shows the layer structure in this example. The luminous reflectance of the low reflective area 11a was 0.13%, whereas the luminous reflectance of the high reflective area 11b was 14.7%. When light was incident from a direction inclined by 5 ° with respect to the normal to the surface of the optical member, a pattern composed of the low reflection region 11a and the high reflection region 11b was visually recognized from the surface of the optical member.

(Example 5)
Except that only a part of the silicon oxide layer (sixteenth layer) constituting the outermost layer of the antireflection film 10 in the thickness direction is removed by etching, the high reflection region 11b is formed in the same manner as in Example 1. Thus, an optical member was produced. Table 5 shows the layer structure in this example. The thickness of the sixteenth layer in the low reflection region 11a was 84.7 nm, and the thickness of the sixteenth layer in the high reflection region 11b was 42.35 nm.

  The luminous reflectance of the low reflective area 11a was 0.13%, while the luminous reflectance of the high reflective area 11b was 5.9%. When light was incident from a direction inclined by 5 ° with respect to the normal to the surface of the optical member, a pattern composed of the low reflection region 11a and the high reflection region 11b was visually recognized from the surface of the optical member.

(Example 6)
The antireflection film 10 having a 16-layer structure as shown in Table 6 is formed, and a niobium oxide layer (seventeenth layer) is further formed on a part of the antireflection film 10, whereby the low reflection region 11 a and the high reflection region are formed. 11b was produced. The low reflection region 11a was formed by removing a part of the 17th niobium oxide layer by etching. The luminous reflectance of the low reflective region 11a was 0.13%, whereas the luminous reflectance of the high reflective region 11b was 40.8%. When light was incident from a direction inclined by 5 ° with respect to the normal to the surface of the optical member, a pattern composed of the low reflection region 11a and the high reflection region 11b was visually recognized from the surface of the optical member.

DESCRIPTION OF SYMBOLS 1 ... Optical member 10 ... Antireflection film 10H ... High refractive index layer 10L ... Low refractive index layer 11 ... Character or design 11a ... Low reflection area 11b ... High reflection area 12 ... Layer 20 ... Base material

Claims (14)

A low-reflection region having a relatively low reflectance,
A high reflection region having a relatively high reflectance, and a character or a pattern is constituted by the low reflection region and the high reflection region,
An optical member in which the low reflection region has an antireflection film.   The optical member according to claim 1, wherein an area of the low reflection region is larger than an area of the high reflection region.   The optical member according to claim 1 or 2, wherein a difference between the luminous reflectance of the low-reflection area and the luminous reflectance of the high-reflection area is 5% or more.   The antireflection film according to any one of claims 1 to 3, wherein a low refractive index layer having a relatively low refractive index and a high refractive index layer having a relatively high refractive index are alternately laminated. The optical member described.   The outermost layer of the antireflection film is constituted by the low refractive index layer, and the refractive index of the outermost layer of the high reflection region is higher than the refractive index of the low refractive index layer. An optical member according to claim 1.   The optical member according to claim 1, wherein the highly reflective region is provided with a film having the same layer configuration as at least a part of the antireflection film.   The optical member according to claim 6, wherein each outermost layer of the low reflection region and the high reflection region is constituted by the low refractive index layer. The thickness of the low refractive index layer constituting the outermost layer of the low reflection region is different from the thickness of the low refractive index layer constituting the outermost layer of the high reflection region,
The film configuration of the portion excluding the low refractive index layer constituting the outermost layer of the low reflection region and the film configuration of the portion excluding the low refractive index layer constituting the outermost layer of the high reflection region The optical member according to claim 7, which is the same.   The optical member according to claim 6, wherein a thickness of the film provided in the high reflection region is smaller than a thickness of the film provided in the low reflection region.   The optical member according to claim 9, wherein a difference between a thickness of the film provided in the high reflection region and a thickness of the film provided in the low reflection region is 420 nm or less.   The optical member according to any one of claims 6 to 10, wherein the film provided in the high reflection region is formed by removing a part of the layer on the surface side of the antireflection film. Forming an antireflection film on the substrate;
By etching a part of the antireflection film, a part of the part along the thickness direction is removed, and a character or a pattern is constituted by the etched part and the unetched part of the antireflection film. And the process of
A method for producing an optical member. Forming an antireflection film on the substrate;
Forming a layer having a refractive index higher than a refractive index of a surface of the antireflection film on a part of the antireflection film;
A method for producing an optical member.   The optical system according to claim 12 or 13, wherein the antireflection film is formed by alternately laminating a low refractive index layer having a relatively low refractive index and a high refractive index layer having a relatively high refractive index. Manufacturing method of member.

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