WO2024048127A1 - Prism, glass article, and method for manufacturing prism - Google Patents

Prism, glass article, and method for manufacturing prism Download PDF

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Publication number
WO2024048127A1
WO2024048127A1 PCT/JP2023/027060 JP2023027060W WO2024048127A1 WO 2024048127 A1 WO2024048127 A1 WO 2024048127A1 JP 2023027060 W JP2023027060 W JP 2023027060W WO 2024048127 A1 WO2024048127 A1 WO 2024048127A1
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Prior art keywords
prism
glass
glass member
cross
prism body
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PCT/JP2023/027060
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French (fr)
Japanese (ja)
Inventor
光佑 吉田
義正 山口
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日本電気硝子株式会社
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Publication of WO2024048127A1 publication Critical patent/WO2024048127A1/en

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    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B11/00—Pressing molten glass or performed glass reheated to equivalent low viscosity without blowing
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00—Glass compositions
    • C03C3/04—Glass compositions containing silica
    • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
    • C03C3/089—Glass compositions containing silica with 40% to 90% silica, by weight containing boron
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/04—Prisms

Definitions

  • the present invention relates to a prism, a glass article, and a method for manufacturing a prism.
  • Prisms are widely used as main components of various optical devices. Prisms include those having a glass prism body (hereinafter sometimes simply referred to as a prism body) having a polygonal prism shape such as a triangular prism shape.
  • the prism body has a plurality of optically functional surfaces on its side surfaces, and both end surfaces are non-optically functional surfaces.
  • a functional film such as an antireflection film is formed on the optically functional surface of the prism body, if necessary.
  • This type of prism body is manufactured, for example, by press-molding a spherical or cylindrical glass base material while heating it (see, for example, Patent Document 1).
  • Prisms are also used in endoscopes, and in the field of endoscopy there is a medical need to insert them into very narrow tubes and holes, such as blood vessels, to observe the inside.
  • endoscopes are required to be further miniaturized.
  • minute prisms mainly prism bodies
  • glass articles including minute prisms.
  • An object of the present invention is to obtain a minute prism or a glass article provided with a minute prism.
  • the present invention which was created to solve the above problems, is a prism comprising a polygonal columnar glass prism body having a plurality of optical functional surfaces on the side surfaces, the prism body having a polygonal cross section.
  • the prism body has a cross-sectional area of 0.032 mm 2 or less, and at least one side of the plurality of sides defining the cross-section of the prism body is 0.25 mm or less.
  • the surface roughness Ra of the optical functional surface is 50 nm or less.
  • the prism body is formed from borosilicate glass having a glass transition point of 700°C or less and a refractive index nd of 1.4 to 1.9. is preferred.
  • the prism body is formed from such borosilicate glass, fluidity suitable for formation can be easily ensured when stretch molding or press molding is used to manufacture the prism body. In other words, it becomes easier to manufacture the prism body. Furthermore, the refractive index within the range required for the prism body can be easily achieved.
  • the cross section of the prism body is an isosceles triangle.
  • the three corners of the isosceles triangle are defined as apex angle A, base angle B, and base angle C, respectively.
  • base angle B and base angle C do not have to be strictly equal; for example, in the case of "base angle B ⁇ base angle C", the ratio of "base angle C/base angle B" is greater than 1 to 1.2. It doesn't matter if it's less than that. In other words, the lengths of the two equilateral sides of an isosceles triangle do not have to be exactly equal.
  • a lens portion may be provided on the optical functional surface.
  • the prism has a predetermined lens function such as condensing and diffusing light.
  • the prism body and the lens portion are integrally molded.
  • the present invention which was created to solve the above problems, is a glass article that includes a prism having the configuration described in (5) or (6) above, and a glass rod, and the end face of the glass rod. is bonded to an optically functional surface different from the optically functional surface on which the lens portion is provided.
  • a reflective film is provided on the optical functional surface located on the optical path between the optical functional surface to which the glass rod is bonded and the optical functional surface on which the lens portion is provided. Preferably.
  • the glass rod is bonded to the prism body via an adhesive layer, and the refractive index difference between the glass rod and the adhesive layer is 0 to 0. 4, and the difference in refractive index between the adhesive layer and the prism body is preferably 0 to 0.4.
  • the present invention which was created to solve the above problems, is a method for manufacturing a prism including a polygonal columnar glass prism body having a plurality of optically functional surfaces on the side surfaces, the first glass member being heated. a stretch-forming step in which the second glass member is press-molded while being heated to obtain an elongated second glass member; a cutting step of cutting the three glass members to a predetermined length to obtain a prism body, the third glass member having a polygonal cross section, and the cross section of the third glass member having an area of 0. 032 mm 2 or less, and the length of at least one side of the plurality of sides defining the cross section of the third glass member is 0.25 mm or less.
  • the second glass member having a very small cross-sectional area can be easily formed by the stretch forming process.
  • the side surface of the second glass member becomes a fire-shaped surface resulting from stretching and forming, and becomes a very smooth surface.
  • the second glass member can be finished into a third glass member having a polygonal cross section that matches the shape of the cross section of the prism body.
  • the side surface of the third glass member also becomes a smooth surface similar to the side surface of the second glass member, so that it functions sufficiently as an optically functional surface even in an unpolished state. Therefore, by cutting the third glass member in the cutting process, a minute prism body can be obtained. In other words, if this prism body is used, minute prisms can be easily manufactured.
  • the value obtained by dividing the cross-sectional area of the second glass member by the cross-sectional area of the third glass member is 1.01 to 1.1.
  • the cross-sectional area of the second glass member is 0.036 mm 2 or less.
  • the area of the cross section of the second glass member obtained in the stretching process becomes sufficiently small. Therefore, changes in the shape of the second glass member during the press molding process can be suppressed to a small extent, making it easier to precisely process the third glass member.
  • the second glass member has a cylindrical shape.
  • the second glass member having a very small cross-sectional area can be easily formed in the stretch forming process.
  • the cross section of the third glass member is an isosceles triangle.
  • the second glass member is uniformly deformed around the line-symmetrical axis in the press molding process. be able to. Therefore, it becomes easier to precisely mold the third glass member from the second glass member.
  • the second glass member is press molded without restraining both ends in the longitudinal direction.
  • the film forming process can be performed more easily than when the functional film is individually formed on the prism body obtained by cutting the third glass member. . Therefore, prism productivity is improved.
  • FIG. 1 is a perspective view showing a prism according to a first embodiment of the present invention.
  • 2 is a sectional view taken along line AA in FIG. 1.
  • FIG. It is a figure showing the example of use of the prism concerning a first embodiment of the present invention. It is a figure showing the example of use of the prism concerning a first embodiment of the present invention. It is a figure showing the example of use of the prism concerning a first embodiment of the present invention. It is a figure showing the example of use of the prism concerning a first embodiment of the present invention. It is a figure showing the example of use of the prism concerning a first embodiment of the present invention.
  • FIG. 2 is a flow diagram showing a method for manufacturing a prism according to a first embodiment of the present invention.
  • FIG. 2 is a side view showing a stretch forming process included in the prism manufacturing method according to the first embodiment of the present invention.
  • FIG. 2 is a perspective view (with the mold open) showing a press molding process included in the prism manufacturing method according to the first embodiment of the present invention.
  • FIG. 9 is a sectional view taken along line BB in FIG. 9;
  • FIG. 2 is a cross-sectional view (with the mold closed) showing a press molding process included in the prism manufacturing method according to the first embodiment of the present invention.
  • FIG. 3 is a perspective view showing a cutting step included in the prism manufacturing method according to the first embodiment of the present invention. It is a top view which shows the glass article based on 2nd embodiment of this invention. 14 is a view taken along arrow C in FIG. 13.
  • FIG. 7 is a cross-sectional view (with the mold closed) showing a press molding step included in the method for manufacturing a glass article according to the second embodiment of the present invention. It is a perspective view which shows the cutting process included in the manufacturing method of the glass article based on 2nd embodiment of this invention.
  • FIG. 2 is a perspective view showing a prism including a lens portion.
  • the prism 1 according to the first embodiment includes a prism body 2 made of glass.
  • the prism body 2 has a triangular prism shape with three optically functional surfaces 3, 4, and 5 on the sides.
  • Each of the optical functional surfaces 3, 4, and 5 is a flat surface.
  • Two adjacent surfaces of the optical functional surfaces 3, 4, and 5 are connected by connection surfaces (corners) 6, 7, and 8, respectively.
  • the connecting surfaces 7 and 8 are rounded, and the connecting surface 6 has a so-called pin angle, which has a sharper tip than the connecting surfaces 7 and 8.
  • both end surfaces 9 and 10 of the prism body 2 are non-optically functional surfaces.
  • the term "optical functional surface” means a surface that intentionally reflects, refracts, transmits, etc. light in a predetermined direction.
  • the surface roughness Ra of the optical functional surfaces 3, 4, and 5 is preferably 50 nm or less, more preferably 30 nm or less, and even more preferably 10 nm or less.
  • surface roughness Ra means a value measured by a method based on JIS B0601:2001.
  • the cross section of the prism body 2 is an isosceles triangle (for example, a right isosceles triangle) having line symmetry.
  • the apex angle ⁇ 1 of the isosceles triangle is preferably 80 to 100 degrees, more preferably 85 to 95 degrees, and even more preferably 90 degrees.
  • the "cross section” is defined as a cross section perpendicular to the three optical functional surfaces 3, 4, and 5, or a cross section perpendicular to the stretching direction if the stretching direction can be specified.
  • the cross-sectional area of the prism body 2 is 0.032 mm 2 or less.
  • the cross-sectional area of the prism body 2 is preferably 0.011 to 0.032 mm 2 , more preferably 0.016 to 0.025 mm 2 or less, and 0.019 to 0.021 mm 2 It is more preferable.
  • the sides 3a and 4a that are equal sides are the short sides, and the remaining side 5a is the long side (hypotenuse).
  • Two adjacent sides among sides 3a, 4a, and 5a are connected by connection lines 6a, 7a, and 8a, respectively.
  • the connecting lines 7a and 8a have a convex curved shape.
  • the sides 3a, 4a, and 5a are straight lines included in the cross sections of the optical functional surfaces 3, 4, and 5.
  • the connection lines 6a, 7a, 8a are straight lines or curves included in the cross section of the connection surfaces 6, 7, 8.
  • the lengths X1 and X2 of the short sides 3a and 4a are 0.25 mm or less.
  • the lengths X1 and X2 of the short sides 3a and 4a are preferably 0.15 to 0.25 mm, more preferably 0.18 to 0.22 mm, and 0.19 to 0.21 mm. is even more preferable.
  • the length X1 of the short side 3a is defined as the length including the connecting lines 6a, 8a on both sides
  • the length X2 of the short side 4a is defined as the length including the connecting lines 6a, 7a on both sides. defined.
  • the length X3 of the long side 5a is not particularly limited, but is, for example, 0.36 mm or less.
  • the length X3 of the long side 5a is defined as a length including the connecting lines 7a, 8a on both sides.
  • the length X4 between both end surfaces 9 and 10 of the prism body 2 is not particularly limited, but is, for example, 0.25 mm or less.
  • the prism body 2 is made of borosilicate glass, for example.
  • the glass composition of borosilicate glass is expressed in mol%: SiO 2 10-70%, B 2 O 3 5-50%, La 2 O 3 0-50%, Al 2 O 3 0-15%, Li 2 O + Na. 2 O+K 2 O 0-20%, CaO+MgO+SrO+BaO 0-15%.
  • Li 2 O + Na 2 O + K 2 O is the total amount of Li 2 O, Na 2 O, and K 2 O
  • CaO + MgO + SrO + BaO is the total amount of CaO, MgO, SrO, and BaO. .
  • the glass transition point of the prism body 2 is preferably 700°C or lower.
  • the glass transition point is preferably 600°C or lower, more preferably 550°C or lower, and even more preferably 500°C or lower.
  • the "glass transition point” is the value of the first inflection point obtained by crushing a glass sample and using DTA (differential thermal analysis).
  • the refractive index nd of the prism body 2 is preferably 1.4 or more, more preferably 1.45 or more, even more preferably 1.5 or more, particularly preferably 1.55 or more, preferably 1.9 or less, and more preferably It is 1.85 or less, more preferably 1.8 or less, particularly preferably 1.75 or less.
  • refractive index nd means the value of the refractive index for the d-line (wavelength 587.6 nm) measured by an Abbe refractometer.
  • the prism 1 may have a functional film on at least one of the optically functional surfaces 3, 4, and 5 of the prism body 2.
  • the functional film include an antireflection film, a reflective film, and a polarizing film.
  • Examples of use of the prism 1 according to the first embodiment are illustrated in FIGS. 3 to 6. Note that the usage examples of the prism 1 are not limited to these.
  • the light L1 is irradiated onto the optical functional surface 3 of the prism body 2 of the prism 1.
  • the light L irradiated onto the optically functional surface 3 passes through the optically functional surface 3 and enters the prism body 2, travels straight through the prism body 2, and is reflected by the optically functional surface 5.
  • the light L reflected by the optical functional surface 5 travels straight through the prism body 2, passes through the optical functional surface 4, and exits the prism body 2.
  • the light L1 is bent by the prism 1 at a predetermined angle (for example, 90 degrees).
  • an antireflection film is formed on the optical functional surfaces 3 and 4 as necessary.
  • a reflective film is formed on the surface of the optically functional surface 5, if necessary.
  • the lights L2 and L3 are irradiated onto the optical functional surfaces 3 and 4 of the prism body 2 of the prism 1, respectively.
  • the light L2 irradiated onto the optical functional surface 3 is reflected by the optical functional surface 3 without entering the prism body 2.
  • the light L3 irradiated onto the optical functional surface 4 is reflected by the optical functional surface 4 without entering the prism body 2.
  • the lights L2 and L3 are each bent at a predetermined angle (for example, 90 degrees) by the prism 1.
  • a reflective film is formed on the surfaces of the optical functional surfaces 3 and 4 as necessary.
  • the light L4 is irradiated onto the optical functional surface 5 of the prism body 2 of the prism 1.
  • the light L4 irradiated onto the optical functional surface 5 passes through the optical functional surface 5 and enters the prism body 2, travels straight through the prism body 2, and is reflected by the optical functional surface 3.
  • the light L4 reflected by the optical function surface 3 travels straight through the prism body 2 and is reflected by the optical function surface 4.
  • the light L4 reflected by the optically functional surface 4 travels straight through the prism body 2, passes through the optically functional surface 5, and exits the prism body 2.
  • the light L4 is bent by the prism 1 at a predetermined angle (for example, 180 degrees).
  • a reflective film is formed on the surfaces of the optical functional surfaces 3 and 4 as necessary.
  • An antireflection film is formed on the surface of the optically functional surface 5, if necessary.
  • two prisms 1 are combined into a cube.
  • one prism 1 will be referred to as a first prism 1x
  • the other prism 1 will be referred to as a second prism 1y.
  • the optically functional surface 5x of the prism body 2x of the first prism 1x is in contact with the optically functional surface 5y of the prism body 2y of the second prism 1y.
  • a polarizing film S having a beam splitter function is formed on at least one surface of the optical functional surfaces 5x and 5y.
  • the light L5 is irradiated onto the optically functional surface 3x of the prism body 2x of the first prism 1x.
  • the light L5 irradiated onto the optical functional surface 3x passes through the optical functional surface 3x, enters the prism body 2x, and travels straight through the prism body 2x to reach the polarizing film S.
  • a portion Lp of the light L5 that has reached the polarizing film S (for example, a P-polarized component included in the light L) is transmitted through the polarizing film S.
  • the light Lp that has passed through the polarizing film S enters the prism body 2y of the second prism 1y, travels straight through the prism body 2y, passes through the optical functional surface 3y, and exits the prism body 2y.
  • a portion Ls of the light L irradiated onto the polarizing film S (for example, an S-polarized component included in the light L) is reflected by the polarizing film S.
  • the light Ls reflected by the polarizing film S travels straight through the prism body 2x, passes through the optical functional surface 4x, and exits the prism body 2x. Thereby, the light L is separated into two lights Lp and Ls.
  • an antireflection film is formed on the surfaces of the optical functional surfaces 3x, 4x, 3y, and 4y as necessary.
  • the method for manufacturing the prism 1 according to the first embodiment includes a stretch molding step S1, a press molding step S2, and a cutting step S3 in this order.
  • the first glass member 11 is stretched downward while being heated to obtain a long second glass member 12 with a small cross-sectional area.
  • the stretch forming step S1 the upper end of the first glass member 11 is supported by the support part 13, and the first glass member 11 is supplied into the heating furnace 14 while lowering the support part 13. Inside the heating furnace 14, the first glass member 11 is heated and softened by the heater 14a. A pair of stretching rollers 15 are provided below the heating furnace 14 to sandwich the sides of the softened first glass member 11 from both sides. After the softened first glass member 11 is stretched downward by the pair of stretching rollers 15, the second glass member 12 is obtained by cutting it to a predetermined length with the cutter 16.
  • the heating temperature of the first glass member 11 is preferably in the range of +70 to 150° C. above the glass transition point of the first glass member 11, that is, the prism body 2.
  • the downward stretching speed (pulling speed) of the first glass member 11 is preferably 1500 to 3000 mm/min, more preferably 1800 to 2700 mm/min, and even more preferably 2000 to 2500 mm/min. preferable.
  • the first glass member 11 and the second glass member 12 are both cylindrical.
  • the cross section of the first glass member 11 is circular.
  • the cross-sectional area of the first glass member 11 before stretching is preferably 100 to 160 mm 2 , more preferably 110 to 150 mm 2 , and even more preferably 120 to 140 mm 2 .
  • the first glass member 11 has the same glass composition as the prism body 2, and is made of borosilicate glass, for example.
  • the cross section of the second glass member 12 is circular.
  • the cross-sectional area of the second glass member 12 is smaller than the cross-sectional area of the first glass member 11 before stretching.
  • the area of the cross section of the second glass member 12 is preferably 0.011 to 0.033 mm 2 , more preferably 0.016 to 0.026 mm 2 , and more preferably 0.019 to 0.022 mm 2 . It is even more preferable that there be.
  • the elongated cylindrical glass member 12 is press molded while being heated to obtain the elongated third glass member 21 in the shape of a triangular prism.
  • a mold 22 is used in the press molding process S2.
  • the mold 22 includes an upper mold 23 that molds a part of the side surface of the second glass member 12 and a lower mold 24 that molds the remainder of the side surface of the second glass member 12.
  • the upper mold 23 is movable relative to the lower mold 24 in the vertical direction.
  • the lower surface of the upper mold 23 has a flat surface 23a for molding a surface corresponding to the long side 5a (optical functional surface 5) in the cross section of the prism body 2.
  • the upper surface of the lower mold 24 has a V-shaped groove 24a for molding respective surfaces corresponding to the two short sides 3a and 4a (optical functional surfaces 3 and 4) that are equilateral in the cross section of the prism body 2.
  • the opening angle ⁇ 2 of the V-shaped groove 24a is the same as the apex angle ⁇ 1 of the prism body 2.
  • the second glass member 12 is placed in the V-shaped groove 24a of the lower mold 24 with the upper mold 23 and the lower mold 24 opened.
  • the longitudinal direction of the second glass member 12 coincides with the longitudinal direction of the V-shaped groove 24a.
  • the second glass member 12 is heated and softened.
  • the upper mold 23 and the lower mold 24 are closed, and the second glass member 12 is press-molded using the flat surface 23a and the V-shaped groove 24a.
  • the second glass member 12 having a circular cross section is deformed, and a long third glass member 21 having a triangular cross section is obtained.
  • both longitudinal ends of the V-shaped groove 24a of the lower die 24 are open. That is, as shown in FIG. 11, when the upper mold 23 and the lower mold 24 are closed and press-molded, both ends of the second glass member 12 in the longitudinal direction are not restrained by the mold 22. As a result, surplus glass left over when the second glass member 12 is press-molded can be released to both sides of the second glass member 12 in the longitudinal direction. Therefore, variations in size and shape of the second glass member 12 can be tolerated to some extent, and productivity of the prism body 2 is improved.
  • the heating temperature of the second glass member 12 is preferably in the range of +50 to 100° C. above the glass transition point of the second glass member 12, that is, the prism body 2.
  • the second glass member 12 is heated, for example, via a mold 22.
  • the mold 22 is heated by electrical heating, a heater, or the like.
  • the preferred range of the cross-sectional area of the third glass member 21 is the same as the preferred range of the cross-sectional area of the prism body 2.
  • the value obtained by dividing the cross-sectional area of the second glass member 12 by the cross-sectional area of the third glass member 21 is preferably 1.01 to 1.1, and preferably 1.02 to 1.08. is more preferable, and even more preferably 1.03 to 1.06. In this way, the change in the shape of the glass in the press molding step S2 can be suppressed to a small extent, making it easier to precisely process the third glass member 21.
  • the third glass member 21 is cut to a predetermined length using the cutter 31 to obtain a plurality of prism bodies 2.
  • the third glass member 21 is cut to a length of 0.25 mm or less. Note that both ends of the third glass member 21 in the longitudinal direction are discarded, and the prism body 2 is collected from the central part of the third glass member 21 in the longitudinal direction.
  • the second glass member 12 having a very small cross-sectional area can be easily formed by the stretch forming step S1.
  • the side surface of the second glass member 12 is a smooth surface made of a fire-finished surface.
  • the second glass member 12 can be finished into the third glass member 21 having a cross section that matches the cross-sectional shape of the prism body 2.
  • the side surface of the third glass member 21 also becomes a smooth surface similar to the side surface of the second glass member 12, it functions sufficiently as an optically functional surface even in an unpolished state. Therefore, by cutting the third glass member 21 in the cutting step S3, a minute prism main body 2 can be stably obtained. In other words, by using this prism body 2, a minute prism 1 can be easily manufactured.
  • the bubbles are stretched in the stretch forming step S1.
  • bubbles are less likely to be included in the cross section of the prism body 2, and even if bubbles are included, there is an advantage that the bubbles are very small and do not affect the optical characteristics of the prism 1.
  • a glass article 41 according to the second embodiment includes a prism 1 including a lens portion 42 and a glass rod 43.
  • the lens portion 42 includes a convex or concave curved lens.
  • Curved lenses include spherical lenses, aspheric lenses, cylindrical lenses, and the like. In this embodiment, the case where the lens portion 42 is an aspherical convex lens will be exemplified.
  • the lens portion 42 is provided on the optically functional surface 3 (corresponding to the short side 3a in the cross section) of the prism body 2.
  • the lens portion 42 is integrally molded with the prism body 2, and there is no adhesive layer interposed between the lens portion 42 and the prism body 2 to bond them together. Therefore, the lens portion 42 is made of the same glass material as the prism body 2 (for example, borosilicate glass).
  • the lens part 42 and the prism main body 2 may be constructed as separate bodies, and both may be joined with an adhesive.
  • an optical functional surface 5 is located on the optical path between the optical functional surface 3 (corresponding to the short side 3a in the cross section) of the prism body 2 and the optical functional surface 4 (corresponding to the short side 4a in the cross section).
  • a reflective film 44 is formed on the long side 5a (corresponding to the long side 5a in the cross section). Note that the reflective film 44 may not be formed.
  • the glass rod 43 is a rod-shaped glass member. In this embodiment, a case is illustrated in which the glass rod 43 is a cylindrical glass member.
  • the glass rod 43 is made of the same glass material as the prism body 2 (for example, borosilicate glass).
  • One longitudinal end surface 43a of the glass rod 43 is bonded to the optically functional surface 4 of the prism body 2 via an adhesive layer 45.
  • the area of the end surface 43a of the glass rod 43 is, for example, 0.07 to 0.2 mm 2 .
  • the longitudinal dimension X5 of the glass rod 43 is, for example, 0.3 to 1 mm.
  • the difference in refractive index between the glass rod 43 and the adhesive layer 45 is preferably 0 to 0.4.
  • the difference in refractive index between the adhesive layer 45 and the prism body 2 is preferably 0 to 0.4.
  • the refractive index difference between the glass rod 43 and the adhesive layer 45 and the refractive index difference between the adhesive layer 45 and the prism body 2 can be calculated from the refractive index values of each member 2, 43, and 45.
  • the refractive index nd of each of the glass rod 43 and the adhesive layer 45 is preferably 1.4 or more, more preferably 1.45 or more, even more preferably 1.5 or more, particularly preferably 1.55 or more, and preferably 1. It is 9 or less, more preferably 1.85 or less, even more preferably 1.8 or less, particularly preferably 1.75 or less.
  • the prism body 2 and the lens portion 42 do not protrude outside the end surface 43a.
  • the ratio P/Q of the area P of the optically functional surface 4 of the prism body 2 to the area Q of the end surface 43a is preferably 0.95 or less. In this way, the peripheral edge of the end surface 43a of the glass rod 43 is located outside the prism body 2 and the lens part 42, so that it is possible to suppress the prism body 2 and the lens part 42 from coming into contact with other members.
  • the light L6 incident on the glass rod 43 from the end surface 43b on one side in the longitudinal direction of the glass rod 43 propagates inside the glass rod 43, and then the light L6 enters the glass rod 43.
  • the light enters the prism body 2 from the other end surface 43a in the longitudinal direction via the optical functional surface 4 of the prism body 2.
  • the light L6 that has entered the prism body 2 is reflected toward the optical function surface 3 by the reflective film 44 formed on the optical function surface 5 of the prism body 2, and is focused by the lens portion 42.
  • the focused light L6 is irradiated onto a predetermined object 46, and the reflected light from the object 46 propagates in the opposite direction along the same optical path as the light L6 and returns to the end surface 43b of the glass rod 43.
  • the state of the object 46 can be grasped by capturing the reflected light that has returned to the end surface 43b of the glass rod 43 into a predetermined measuring device via an optical fiber or the like and analyzing it. Therefore, the glass article 41 is used, for example, in intravascular OCT (Optical Coherence Tomography). In this case, for example, infrared rays are used as the light L6, and the target object 46 is the inner wall of a blood vessel.
  • OCT Optical Coherence Tomography
  • the method for manufacturing a glass article 41 according to the second embodiment includes a first preparation step S4 in which a prism 1 including a lens portion 42 is prepared, and a second preparation step S5 in which a glass rod 43 is prepared. , and a joining step S6 of joining the prism body 2 of the prism 1 and the glass rod 43. Either of the first preparation step S4 and the second preparation step S5 may be performed first, or they may be performed simultaneously.
  • the stretch molding step S1, the press molding step S2, and the cutting step S3 are performed in this order to obtain the prism body 2.
  • the second embodiment is different from the first embodiment, as shown in FIG. The point is that a plurality of lens portions 42 are simultaneously and integrally molded at intervals in the longitudinal direction. Therefore, as shown in FIGS. 17 and 18, in the cutting step S3, the third glass member 21 including the plurality of lens parts 42 is cut to a predetermined length, thereby forming a prism integrally provided with the lens parts 42.
  • the main body 2 can be easily obtained. Note that the number of lens portions 42 molded on one side surface of the third glass member 21 is not limited to a plurality, and may be one.
  • a glass rod 43 is obtained by a redraw method or the like.
  • the prism body 2 of the prism 1 including the lens portion 42 and the glass rod 43 are bonded via the adhesive layer 45. Thereby, the glass article 1 can be obtained.
  • a film forming process may be performed to form a functional film on the side surface of the third glass member after the press molding process and before the cutting process. In this way, the film forming process can be performed more easily than when the functional film is individually formed on the prism body obtained by cutting the third glass member.
  • the third glass member and the prism body are triangular prisms, but the third glass member and the prism body may be polygonal prisms other than triangular prisms.
  • the second glass member formed in the stretch forming process is cylindrical. It may be a prism (for example, a triangular prism). In this way, the amount of deformation of the second glass member during the press molding process is reduced, so that the molding stability of the prism body is improved.
  • the polygonal column-shaped second glass member can be obtained, for example, by stretch-molding a polygonal column-shaped first glass member having a cross section that is substantially similar to the cross section of the second glass member.
  • Example 1 as shown in FIGS. 8 to 12, a cylindrical preform (corresponding to the second glass member) obtained by stretch molding is press-molded to form a triangular prism-shaped glass member (third glass member).
  • a cylindrical preform (corresponding to the second glass member) obtained by stretch molding is press-molded to form a triangular prism-shaped glass member (third glass member).
  • the cross-sectional area of the cylindrical preform (second glass member) was 0.031 mm 2 .
  • the value obtained by dividing the cross-sectional area of the cylindrical preform (second glass member) by the cross-sectional area of the triangular prism-shaped glass member (third glass member) was 1.04.
  • Comparative Example 1 an attempt was made to manufacture a prism body by molding a spherical gob into a triangular prism-shaped glass member by press molding, and then cutting the glass member to a predetermined length.
  • Comparative Example 2 an attempt was made to form a triangular prism-shaped glass member by polishing a gob of a predetermined shape, and then cut the glass member to a predetermined length to manufacture a prism body.
  • Example 1 and Comparative Examples 1 and 2 had a glass composition, in terms of mol%, of 50% SiO 2 , 20% B 2 O 3 , 15% La 2 O 3 , 5% ZnO, and Al 2 O 3 Borosilicate glass containing 5% Na 2 O and 5% Na 2 O was used.
  • the presence or absence of bubbles in the prism body was observed using an optical microscope (50x magnification).
  • the mass productivity of the prism body was judged in three stages: " ⁇ ", " ⁇ ", and “ ⁇ ".
  • ⁇ means that the number of high quality prism bodies obtained was 900 or more.
  • ⁇ means that the number of high quality prism bodies obtained was 500 to 899.
  • X means that less than 500 high quality prism bodies were obtained.
  • high quality means that the short side of the cross section of the prism body has a predetermined length, and there is no cracking or chipping that would affect optical properties.
  • Example 1 even a small prism body with a short side length of 0.25 mm or less in the cross section (the area of the cross section was 0.032 mm 2 or less) could be successfully mass-produced. .
  • Comparative Example 1 it was not possible to manufacture a prism body in which the length of the short side in the cross section was 0.30 mm or less.
  • Comparative Example 2 as the length of the short side in the cross section becomes smaller, the mass productivity of the prism body deteriorates. It was not possible to manufacture a small prism body with a diameter of .032 mm 2 or less.
  • Example 1 no bubbles were observed in the prism body, whereas in Comparative Examples 1 and 2, bubbles were observed in each. Bubbles can adversely affect the optical properties of the prism. Therefore, the prism according to Example 1 has better optical characteristics than the prism according to the comparative example.

Abstract

A method for manufacturing a prism 1 provided with a polygonal column-shaped glass prism body 2 having a plurality of optical functional surfaces as side surfaces comprises: a stretch molding step S1 for stretch-molding a first glass member 11 to obtain a long second glass member 12; a press molding step S2 for press-molding the second glass member 12 to obtain a polygonal column-shaped long third glass member 21; and a cutting step S3 for cutting the third glass member 21 to a predetermined length to obtain the prism body 2. The third glass member 21 has a polygonal cross section. The area of the cross section of the third glass member 21 is 0.032 mm2 or less. The length of at least one side among a plurality of sides demarcating the cross section of the third glass member 21 is 0.25 mm or less.

Description

プリズム、ガラス物品及びプリズムの製造方法Prism, glass article and method for manufacturing prism
　本発明は、プリズム、ガラス物品及びプリズムの製造方法に関する。 The present invention relates to a prism, a glass article, and a method for manufacturing a prism.
　プリズムは、各種光学機器の主要部品として広く利用されている。プリズムとしては、三角柱形状などの多角柱形状をなすガラス製プリズム本体（以下、単にプリズム本体という場合がある）を備えるものが挙げられる。プリズム本体は、側面に複数の光学機能面を有し、両端面は非光学機能面とされる。プリズム本体の光学機能面の表面には、必要に応じて反射防止膜などの機能膜が形成される。 Prisms are widely used as main components of various optical devices. Prisms include those having a glass prism body (hereinafter sometimes simply referred to as a prism body) having a polygonal prism shape such as a triangular prism shape. The prism body has a plurality of optically functional surfaces on its side surfaces, and both end surfaces are non-optically functional surfaces. A functional film such as an antireflection film is formed on the optically functional surface of the prism body, if necessary.
　この種のプリズム本体は、例えば、球状や円柱状のガラス母材を加熱しながらプレス成型することにより製造される（例えば、特許文献１を参照）。 This type of prism body is manufactured, for example, by press-molding a spherical or cylindrical glass base material while heating it (see, for example, Patent Document 1).
国際公開第２００７／０５８０９７号International Publication No. 2007/058097
　プリズムは内視鏡にも用いられているが、内視鏡の分野では、血管のような非常に径が細い管や孔に挿入して内部を観察したいという医学的要請がある。このような要請を達成するために、内視鏡にはさらなる小型化が求められている。そして、このような内視鏡の小型化の一環として、微小なプリズム（主にプリズム本体）や、微小なプリズムを備えるガラス物品の製造が求められている。 Prisms are also used in endoscopes, and in the field of endoscopy there is a medical need to insert them into very narrow tubes and holes, such as blood vessels, to observe the inside. In order to meet these demands, endoscopes are required to be further miniaturized. As part of the miniaturization of such endoscopes, there is a need to manufacture minute prisms (mainly prism bodies) and glass articles including minute prisms.
　しかしながら、従来の製造方法では、内視鏡の分野の医学的要請を達成し得る、微小なプリズムを製造することは困難であった。 However, with conventional manufacturing methods, it has been difficult to manufacture minute prisms that can meet the medical needs of the endoscope field.
　つまり、従来のプレス成型用のガラス母材の横断面の面積は、内視鏡の分野の医学的要請を達成し得る、微小なプリズム本体を成型する上では大きすぎるという問題があった。そのため、微小なプリズム本体を得るには、プレス時にガラス母材の横断面の面積が小さくなるように、ガラス母材を大きく変形させる必要が生じる。その結果、ガラス母材の変形量が大きくなりすぎて加工不良が生じ、所望の形状を有する微小なプリズム本体を製造できなかった。なお、プレス前にガラス母材の側面を研磨して、プリズム本体の加工不良が生じない程度までガラス母材の横断面の面積を小さくすることも考えられる。しかしながら、この場合、研磨中にガラス母材に割れ等の破損が生じ、所望の形状を有する微小なプリズム本体の製造が困難であった。 In other words, there was a problem in that the cross-sectional area of the conventional glass base material for press molding was too large for molding a minute prism body that could meet the medical requirements of the endoscope field. Therefore, in order to obtain a minute prism body, it is necessary to greatly deform the glass base material during pressing so that the cross-sectional area of the glass base material becomes small. As a result, the amount of deformation of the glass base material became too large, resulting in processing defects, making it impossible to manufacture a minute prism body having a desired shape. It is also conceivable to polish the side surfaces of the glass base material before pressing to reduce the cross-sectional area of the glass base material to the extent that processing defects of the prism body do not occur. However, in this case, damage such as cracking occurs in the glass base material during polishing, making it difficult to manufacture a minute prism body having a desired shape.
　本発明は、微小なプリズムや、微小なプリズムを備えるガラス物品を得ることを課題とする。 An object of the present invention is to obtain a minute prism or a glass article provided with a minute prism.
（１）　上記の課題を解決するために創案された本発明は、複数の光学機能面を側面に有する多角柱状のガラス製プリズム本体を備えるプリズムであって、プリズム本体が、多角形状の横断面を有し、プリズム本体の横断面の面積が、０．０３２ｍｍ2以下であり、プリズム本体の横断面を区画する複数の辺のうち少なくとも一辺が、０．２５ｍｍ以下であることを特徴とする。 (1) The present invention, which was created to solve the above problems, is a prism comprising a polygonal columnar glass prism body having a plurality of optical functional surfaces on the side surfaces, the prism body having a polygonal cross section. The prism body has a cross-sectional area of 0.032 mm 2 or less, and at least one side of the plurality of sides defining the cross-section of the prism body is 0.25 mm or less.
　このようにすれば、例えば内視鏡の分野の医学的要請なども達成し得る、微小なプリズムとなる。 In this way, it becomes a minute prism that can meet medical requirements in the field of endoscopy, for example.
（２）　上記（１）の構成において、光学機能面の表面粗さＲａが、５０ｎｍ以下であることが好ましい。 (2) In the configuration of (1) above, it is preferable that the surface roughness Ra of the optical functional surface is 50 nm or less.
　このようにすれば、光学機能面において十分な平滑性が実現できる。そのため、光学機能面における光の散乱等による損失を抑制できるため、高性能なプリズムを提供できる。 In this way, sufficient smoothness can be achieved in terms of optical function. Therefore, it is possible to suppress losses due to light scattering and the like on the optical functional surface, so that a high-performance prism can be provided.
（３）　上記（１）又は（２）の構成において、プリズム本体は、ガラス転移点が７００℃以下、かつ、屈折率ｎｄが１．４～１．９であるホウケイ酸ガラスから形成されることが好ましい。 (3) In the configuration of (1) or (2) above, the prism body is formed from borosilicate glass having a glass transition point of 700°C or less and a refractive index nd of 1.4 to 1.9. is preferred.
　このようなホウケイ酸ガラスからプリズム本体を形成すれば、プリズム本体を製造する際に延伸成形やプレス成型を用いた場合に、形成に適した流動性を確保しやすくなる。つまり、プリズム本体を製造しやすくなる。また、プリズム本体に要求される範囲の屈折率も容易に実現できる。 If the prism body is formed from such borosilicate glass, fluidity suitable for formation can be easily ensured when stretch molding or press molding is used to manufacture the prism body. In other words, it becomes easier to manufacture the prism body. Furthermore, the refractive index within the range required for the prism body can be easily achieved.
（４）　上記（１）～（３）のいずれかの構成において、プリズム本体の横断面が、二等辺三角形であることが好ましい。ここで、微小なプリズムに用いるプレス成型の金型の作製は難しく、作製コストが高くなることを考慮すると、二等辺三角形の３つの角をそれぞれ頂角Ａ、底角Ｂ、底角Ｃ、とすると、底角Ｂと底角Ｃは厳密に等しい必要はなく、例えば、「底角Ｂ＜底角Ｃ」の場合、「底角Ｃ／底角Ｂ」の比は、１超から１．２以下でも構わない。つまり、二等辺三角形の２つの等辺の長さも厳密に等しい必要はない。 (4) In any of the configurations (1) to (3) above, it is preferable that the cross section of the prism body is an isosceles triangle. Considering that it is difficult and expensive to produce a press molding die used for minute prisms, the three corners of the isosceles triangle are defined as apex angle A, base angle B, and base angle C, respectively. Then, base angle B and base angle C do not have to be strictly equal; for example, in the case of "base angle B<base angle C", the ratio of "base angle C/base angle B" is greater than 1 to 1.2. It doesn't matter if it's less than that. In other words, the lengths of the two equilateral sides of an isosceles triangle do not have to be exactly equal.
　このようにすれば、プレス成型などを用いて、プリズム本体の形状を精密に形成しやすくなる。 In this way, it becomes easier to precisely form the shape of the prism body using press molding or the like.
（５）　上記（１）～（４）のいずれかの構成において、光学機能面にレンズ部を備えていてもよい。 (5) In any of the configurations (1) to (4) above, a lens portion may be provided on the optical functional surface.
　このようにすれば、光を集光したり拡散したりするなどの所定のレンズ機能を有するプリズムとなる。 In this way, the prism has a predetermined lens function such as condensing and diffusing light.
（６）　上記（５）の構成において、プリズム本体とレンズ部とが一体成型されてなることが好ましい。 (6) In the configuration of (5) above, it is preferable that the prism body and the lens portion are integrally molded.
　このようにすれば、プリズム本体とレンズ部との間に接着層を設ける必要がないため、製造工程を少なくすることができるとともに、光学特性が良好になる。 In this way, since there is no need to provide an adhesive layer between the prism body and the lens portion, the number of manufacturing steps can be reduced, and the optical properties are improved.
（７）　上記の課題を解決するために創案された本発明は、ガラス物品であって、上記（５）又は（６）の構成を備えたプリズムと、ガラスロッドとを備え、ガラスロッドの端面が、レンズ部が設けられた光学機能面とは別の光学機能面に接合されていることを特徴とする。 (7) The present invention, which was created to solve the above problems, is a glass article that includes a prism having the configuration described in (5) or (6) above, and a glass rod, and the end face of the glass rod. is bonded to an optically functional surface different from the optically functional surface on which the lens portion is provided.
　このようにすれば、例えば内視鏡の分野の医学的要請なども達成し得る、微小なプリズムを備えるガラス物品となる。 In this way, a glass article with minute prisms can be obtained, which can also meet medical requirements in the field of endoscopy, for example.
（８）　上記（７）の構成において、ガラスロッドが接合された光学機能面と、レンズ部が設けられた光学機能面との間の光路上に位置する光学機能面に反射膜が設けられていることが好ましい。 (8) In the configuration of (7) above, a reflective film is provided on the optical functional surface located on the optical path between the optical functional surface to which the glass rod is bonded and the optical functional surface on which the lens portion is provided. Preferably.
　このようにすれば、ガラスロッドからレンズ部、あるいは、レンズ部からガラスロッドに、プリズム（プリズム本体）を介して確実に光を伝搬させることができる。 In this way, light can be reliably propagated from the glass rod to the lens portion or from the lens portion to the glass rod via the prism (prism body).
（９）　上記（７）又は（８）の構成において、ガラスロッドの端面を、端面と直交する方向から見た場合に、プリズム本体及びレンズ部が、端面の外側に食み出さないことが好ましい。 (9) In the configuration of (7) or (8) above, when the end face of the glass rod is viewed from a direction perpendicular to the end face, it is preferable that the prism body and the lens portion do not protrude outside the end face. .
　このようにすれば、ガラス物品を有する光学プローブを、血管内に挿入する筒であるシース内に収納する際、プリズム本体及びレンズ部が、シースの内壁と直接接触しにくくなる。 This makes it difficult for the prism body and lens portion to come into direct contact with the inner wall of the sheath when the optical probe having the glass article is housed in the sheath, which is a tube inserted into a blood vessel.
（１０）　上記（７）～（９）のいずれかの構成において、ガラスロッドが、接着層を介してプリズム本体に接合されており、ガラスロッドと接着層との屈折率差が０～０．４であり、接着層とプリズム本体との屈折率差が０～０．４であることが好ましい。 (10) In any of the configurations (7) to (9) above, the glass rod is bonded to the prism body via an adhesive layer, and the refractive index difference between the glass rod and the adhesive layer is 0 to 0. 4, and the difference in refractive index between the adhesive layer and the prism body is preferably 0 to 0.4.
　このようにすれば、ガラスロッドと接着層との界面や、接着層とプリズム本体との界面で、不当な屈折や反射が生じにくくなる。 In this way, undue refraction and reflection are less likely to occur at the interface between the glass rod and the adhesive layer, or at the interface between the adhesive layer and the prism body.
（１１）　上記の課題を解決するために創案された本発明は、複数の光学機能面を側面に有する多角柱状のガラス製プリズム本体を備えるプリズムの製造方法であって、第一ガラス部材を加熱しながら延伸成形し、長尺な第二ガラス部材を得る延伸成形工程と、第二ガラス部材を加熱しながらプレス成型し、多角柱状の長尺な第三ガラス部材を得るプレス成型工程と、第三ガラス部材を所定の長さで切断し、プリズム本体を得る切断工程とを備え、第三ガラス部材が、多角形状の横断面を有し、第三ガラス部材の横断面の面積が、０．０３２ｍｍ2以下であり、第三ガラス部材の横断面を区画する複数の辺のうち少なくとも一辺の長さが、０．２５ｍｍ以下であることを特徴とする。 (11) The present invention, which was created to solve the above problems, is a method for manufacturing a prism including a polygonal columnar glass prism body having a plurality of optically functional surfaces on the side surfaces, the first glass member being heated. a stretch-forming step in which the second glass member is press-molded while being heated to obtain an elongated second glass member; a cutting step of cutting the three glass members to a predetermined length to obtain a prism body, the third glass member having a polygonal cross section, and the cross section of the third glass member having an area of 0. 032 mm 2 or less, and the length of at least one side of the plurality of sides defining the cross section of the third glass member is 0.25 mm or less.
　このようにすれば、延伸成形工程によって、横断面の面積が非常に小さい第二ガラス部材を容易に成形できる。加えて、第二ガラス部材の側面は、延伸成形に由来する火造り面となり、非常に平滑な面となる。そして、プレス成型工程によって、第二ガラス部材を、プリズム本体の横断面の形状と一致する多角形状の横断面を有する第三ガラス部材に仕上げ加工できる。この際、第三ガラス部材の側面も、第二ガラス部材の側面に準じた平滑な面となるため、未研磨の状態でも光学機能面として十分に機能する。したがって、切断工程で第三ガラス部材を切断すれば、微小なプリズム本体を得ることができる。つまり、このプリズム本体を用いれば、微小なプリズムを容易に製造できる。 In this way, the second glass member having a very small cross-sectional area can be easily formed by the stretch forming process. In addition, the side surface of the second glass member becomes a fire-shaped surface resulting from stretching and forming, and becomes a very smooth surface. Then, through the press molding process, the second glass member can be finished into a third glass member having a polygonal cross section that matches the shape of the cross section of the prism body. At this time, the side surface of the third glass member also becomes a smooth surface similar to the side surface of the second glass member, so that it functions sufficiently as an optically functional surface even in an unpolished state. Therefore, by cutting the third glass member in the cutting process, a minute prism body can be obtained. In other words, if this prism body is used, minute prisms can be easily manufactured.
（１２）　上記（１１）の構成において、第二ガラス部材の横断面の面積を第三ガラス部材の横断面の面積で除した値が、１．０１～１．１であることが好ましい。 (12) In the configuration of (11) above, it is preferable that the value obtained by dividing the cross-sectional area of the second glass member by the cross-sectional area of the third glass member is 1.01 to 1.1.
　このようにすれば、プレス成型工程における第二ガラス部材の形状変化を小さく抑えることができるため、第三ガラス部材を精密に加工しやすくなる。 In this way, changes in the shape of the second glass member during the press molding process can be suppressed to a small extent, making it easier to precisely process the third glass member.
（１３）　上記（１１）又は（１２）の構成において、第二ガラス部材の横断面の面積が、０．０３６ｍｍ2以下であることが好ましい。 (13) In the configuration of (11) or (12) above, it is preferable that the cross-sectional area of the second glass member is 0.036 mm 2 or less.
　このようにすれば、延伸成形工程で得られる第二ガラス部材の横断面の面積が十分に小さくなる。そのため、プレス成型工程における第二ガラス部材の形状変化を小さく抑えることができるため、第三ガラス部材を精密に加工しやすくなる。 In this way, the area of the cross section of the second glass member obtained in the stretching process becomes sufficiently small. Therefore, changes in the shape of the second glass member during the press molding process can be suppressed to a small extent, making it easier to precisely process the third glass member.
（１４）　上記（１１）～（１３）のいずれかの構成において、第二ガラス部材が、円柱状であることが好ましい。 (14) In any of the configurations (11) to (13) above, it is preferable that the second glass member has a cylindrical shape.
　このようにすれば、延伸成形工程において、横断面の面積が非常に小さい第二ガラス部材を容易に成形できる。 In this way, the second glass member having a very small cross-sectional area can be easily formed in the stretch forming process.
（１５）　上記（１４）の構成において、第三ガラス部材の横断面が、二等辺三角形であることが好ましい。 (15) In the configuration of (14) above, it is preferable that the cross section of the third glass member is an isosceles triangle.
　このようにすれば、第二ガラス部材及び第三ガラス部材のそれぞれの横断面が、線対称形状をなすため、プレス成型工程で、第二ガラス部材を、線対称軸を中心として均等に変形させることができる。そのため、第二ガラス部材から第三ガラス部材を精密に成型しやすくなる。 In this way, since the cross sections of the second glass member and the third glass member form a line-symmetrical shape, the second glass member is uniformly deformed around the line-symmetrical axis in the press molding process. be able to. Therefore, it becomes easier to precisely mold the third glass member from the second glass member.
（１６）　上記（１１）～（１５）のいずれかの構成において、プレス成型工程では、第二ガラス部材の長手方向の両端部を拘束しない状態でプレス成型することが好ましい。 (16) In any of the configurations (11) to (15) above, in the press molding step, it is preferable that the second glass member is press molded without restraining both ends in the longitudinal direction.
　このようにすれば、第二ガラス部材をプレス成型した際に余った余剰ガラスを、第二ガラス部材の長手方向の両側に逃がすことができる。したがって、第二ガラス部材の寸法や形状のばらつきをある程度許容でき、プリズムの生産性が向上する。 In this way, the excess glass left over when the second glass member is press-molded can be released to both sides of the second glass member in the longitudinal direction. Therefore, variations in size and shape of the second glass member can be tolerated to some extent, and productivity of the prism is improved.
（１７）　上記（１１）～（１６）のいずれかの構成において、切断工程の前に、第三ガラス部材の側面に機能膜を形成する成膜工程を備えることが好ましい。 (17) In any of the configurations (11) to (16) above, it is preferable to include a film forming step of forming a functional film on the side surface of the third glass member before the cutting step.
　このように第三ガラス部材に機能膜を形成すれば、第三ガラス部材を切断して得られるプリズム本体に個別に機能膜を形成する場合に比べて、成膜工程を容易に行うことができる。したがって、プリズムの生産性が向上する。 If the functional film is formed on the third glass member in this way, the film forming process can be performed more easily than when the functional film is individually formed on the prism body obtained by cutting the third glass member. . Therefore, prism productivity is improved.
　本発明によれば、微小なプリズムや、微小なプリズムを備えるガラス物品を得ることができる。 According to the present invention, it is possible to obtain a minute prism or a glass article provided with a minute prism.
本発明の第一実施形態に係るプリズムを示す斜視図である。FIG. 1 is a perspective view showing a prism according to a first embodiment of the present invention. 図１のＡ－Ａ断面図である。2 is a sectional view taken along line AA in FIG. 1. FIG. 本発明の第一実施形態に係るプリズムの使用例を示す図である。It is a figure showing the example of use of the prism concerning a first embodiment of the present invention. 本発明の第一実施形態に係るプリズムの使用例を示す図である。It is a figure showing the example of use of the prism concerning a first embodiment of the present invention. 本発明の第一実施形態に係るプリズムの使用例を示す図である。It is a figure showing the example of use of the prism concerning a first embodiment of the present invention. 本発明の第一実施形態に係るプリズムの使用例を示す図である。It is a figure showing the example of use of the prism concerning a first embodiment of the present invention. 本発明の第一実施形態に係るプリズムの製造方法を示すフロー図である。FIG. 2 is a flow diagram showing a method for manufacturing a prism according to a first embodiment of the present invention. 本発明の第一実施形態に係るプリズムの製造方法に含まれる延伸成形工程を示す側面図である。FIG. 2 is a side view showing a stretch forming process included in the prism manufacturing method according to the first embodiment of the present invention. 本発明の第一実施形態に係るプリズムの製造方法に含まれるプレス成型工程を示す斜視図（金型を開いた状態）である。FIG. 2 is a perspective view (with the mold open) showing a press molding process included in the prism manufacturing method according to the first embodiment of the present invention. 図９のＢ－Ｂ断面図である。FIG. 9 is a sectional view taken along line BB in FIG. 9; 本発明の第一実施形態に係るプリズムの製造方法に含まれるプレス成型工程を示す断面図（金型を閉じた状態）である。FIG. 2 is a cross-sectional view (with the mold closed) showing a press molding process included in the prism manufacturing method according to the first embodiment of the present invention. 本発明の第一実施形態に係るプリズムの製造方法に含まれる切断工程を示す斜視図である。FIG. 3 is a perspective view showing a cutting step included in the prism manufacturing method according to the first embodiment of the present invention. 本発明の第二実施形態に係るガラス物品を示す平面図である。It is a top view which shows the glass article based on 2nd embodiment of this invention. 図１３のＣ矢視図である。14 is a view taken along arrow C in FIG. 13. FIG. 本発明の第二実施形態に係るガラス物品の製造方法を示すフロー図である。It is a flowchart which shows the manufacturing method of the glass article based on 2nd embodiment of this invention. 本発明の第二実施形態に係るガラス物品の製造方法に含まれるプレス成型工程を示す断面図（金型を閉じた状態）である。FIG. 7 is a cross-sectional view (with the mold closed) showing a press molding step included in the method for manufacturing a glass article according to the second embodiment of the present invention. 本発明の第二実施形態に係るガラス物品の製造方法に含まれる切断工程を示す斜視図である。It is a perspective view which shows the cutting process included in the manufacturing method of the glass article based on 2nd embodiment of this invention. レンズ部を備えるプリズムを示す斜視図である。FIG. 2 is a perspective view showing a prism including a lens portion.
　以下、本発明を実施するための形態について図面を参照しながら説明する。なお、各実施形態において対応する構成要素には同一符号を付すことにより、重複する説明を省略する場合がある。各実施形態において構成の一部分のみを説明している場合、当該構成の他の部分については、先行して説明した他の実施形態の構成を適用することができる。また、各実施形態の説明において明示している構成の組み合わせばかりではなく、特に組み合わせに支障が生じなければ、明示していなくても複数の実施形態の構成同士を部分的に組み合わせることができる。 Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Note that redundant explanation may be omitted by assigning the same reference numerals to corresponding components in each embodiment. When only a part of the configuration is described in each embodiment, the configuration of the other embodiments previously described can be applied to other parts of the configuration. Furthermore, in addition to the combinations of configurations specified in the description of each embodiment, configurations of a plurality of embodiments may be partially combined even if not explicitly specified, as long as no particular problem arises in the combination.
＜第一実施形態＞
（プリズム）
　図１及び図２に示すように、第一実施形態に係るプリズム１は、ガラス製のプリズム本体２を備える。 <First embodiment>
(prism)
As shown in FIGS. 1 and 2, the prism 1 according to the first embodiment includes a prism body 2 made of glass.
　プリズム本体２は、３つの光学機能面３、４、５を側面に有する三角柱状である。光学機能面３、４、５は、それぞれ平面で構成される。光学機能面３、４、５のうち隣接する２つの面は、それぞれ接続面（角部）６、７、８によって接続されている。本実施形態では、接続面７、８は、Ｒ面状であり、接続面６は、接続面７、８よりも先端が尖った、いわゆるピン角である。なお、プリズム本体２の両端面９、１０は、非光学機能面とされる。ここで、「光学機能面」とは、予め決められた方向に光を意図的に反射・屈折・透過等する面を意味する。 The prism body 2 has a triangular prism shape with three optically functional surfaces 3, 4, and 5 on the sides. Each of the optical functional surfaces 3, 4, and 5 is a flat surface. Two adjacent surfaces of the optical functional surfaces 3, 4, and 5 are connected by connection surfaces (corners) 6, 7, and 8, respectively. In this embodiment, the connecting surfaces 7 and 8 are rounded, and the connecting surface 6 has a so-called pin angle, which has a sharper tip than the connecting surfaces 7 and 8. Note that both end surfaces 9 and 10 of the prism body 2 are non-optically functional surfaces. Here, the term "optical functional surface" means a surface that intentionally reflects, refracts, transmits, etc. light in a predetermined direction.
　光学機能面３、４、５の表面粗さＲａは、５０ｎｍ以下であることが好ましく、３０ｎｍ以下であることがより好ましく、１０ｎｍ以下であることがさらに好ましい。ここで、「表面粗さＲａ」は、ＪＩＳ　Ｂ０６０１：２００１に準拠した方法で測定した値を意味する。 The surface roughness Ra of the optical functional surfaces 3, 4, and 5 is preferably 50 nm or less, more preferably 30 nm or less, and even more preferably 10 nm or less. Here, "surface roughness Ra" means a value measured by a method based on JIS B0601:2001.
　図２に示すように、プリズム本体２の横断面は、線対称性を有する二等辺三角形（例えば、直角二等辺三角形）である。二等辺三角形の頂角（等辺のなす角）θ１は、好ましくは８０～１００度、より好ましくは８５～９５度、さらに好ましくは９０度である。ここで、「横断面」は、３つの光学機能面３、４、５と直交する断面、あるいは、延伸方向が特定できる場合には延伸方向と直交する断面で定義される。 As shown in FIG. 2, the cross section of the prism body 2 is an isosceles triangle (for example, a right isosceles triangle) having line symmetry. The apex angle θ1 of the isosceles triangle (angle formed by equilateral sides) is preferably 80 to 100 degrees, more preferably 85 to 95 degrees, and even more preferably 90 degrees. Here, the "cross section" is defined as a cross section perpendicular to the three optical functional surfaces 3, 4, and 5, or a cross section perpendicular to the stretching direction if the stretching direction can be specified.
　プリズム本体２の横断面の面積は、０．０３２ｍｍ2以下である。プリズム本体２の横断面の面積は、０.０１１～０.０３２ｍｍ2であることが好ましく、０.０１６～０.０２５ｍｍ2以下であることがより好ましく、０.０１９～０.０２１ｍｍ2であることがより好ましい。 The cross-sectional area of the prism body 2 is 0.032 mm 2 or less. The cross-sectional area of the prism body 2 is preferably 0.011 to 0.032 mm 2 , more preferably 0.016 to 0.025 mm 2 or less, and 0.019 to 0.021 mm 2 It is more preferable.
　プリズム本体２の横断面を区画する３つの辺３ａ、４ａ、５ａのうち、等辺である辺３ａ、４ａが短辺、残りの辺５ａが長辺（斜辺）である。辺３ａ、４ａ、５ａのうち隣接する２つの辺は、それぞれ接続線６ａ、７ａ、８ａによって接続されている。本実施形態では、接続線７ａ、８ａは、凸曲線状である。なお、辺３ａ、４ａ、５ａは、光学機能面３、４、５の横断面に含まれる直線である。接続線６ａ、７ａ、８ａは、接続面６、７、８の横断面に含まれる直線又は曲線である。 Among the three sides 3a, 4a, and 5a that partition the cross section of the prism body 2, the sides 3a and 4a that are equal sides are the short sides, and the remaining side 5a is the long side (hypotenuse). Two adjacent sides among sides 3a, 4a, and 5a are connected by connection lines 6a, 7a, and 8a, respectively. In this embodiment, the connecting lines 7a and 8a have a convex curved shape. Note that the sides 3a, 4a, and 5a are straight lines included in the cross sections of the optical functional surfaces 3, 4, and 5. The connection lines 6a, 7a, 8a are straight lines or curves included in the cross section of the connection surfaces 6, 7, 8.
　短辺３ａ、４ａの長さＸ１，Ｘ２は、０．２５ｍｍ以下である。短辺３ａ、４ａの長さＸ１，Ｘ２は、０.１５～０.２５ｍｍであることが好ましく、０.１８～０.２２ｍｍであることがより好ましく、０.１９～０.２１ｍｍであることがさらに好ましい。本実施形態では、短辺３ａの長さＸ１は、両側の接続線６ａ、８ａを含む長さで定義され、短辺４ａの長さＸ２は、両側の接続線６ａ、７ａを含む長さで定義される。 The lengths X1 and X2 of the short sides 3a and 4a are 0.25 mm or less. The lengths X1 and X2 of the short sides 3a and 4a are preferably 0.15 to 0.25 mm, more preferably 0.18 to 0.22 mm, and 0.19 to 0.21 mm. is even more preferable. In this embodiment, the length X1 of the short side 3a is defined as the length including the connecting lines 6a, 8a on both sides, and the length X2 of the short side 4a is defined as the length including the connecting lines 6a, 7a on both sides. defined.
　長辺５ａの長さＸ３は、特に限定されるものではないが、例えば０．３６ｍｍ以下である。本実施形態では、長辺５ａの長さＸ３は、両側の接続線７ａ、８ａを含む長さで定義される。 The length X3 of the long side 5a is not particularly limited, but is, for example, 0.36 mm or less. In this embodiment, the length X3 of the long side 5a is defined as a length including the connecting lines 7a, 8a on both sides.
　プリズム本体２の両端面９、１０の間の長さＸ４は、特に限定されるものではないが、例えば０．２５ｍｍ以下である。 The length X4 between both end surfaces 9 and 10 of the prism body 2 is not particularly limited, but is, for example, 0.25 mm or less.
　プリズム本体２は、例えば、ホウケイ酸ガラスから形成される。ホウケイ酸ガラスのガラス組成は、モル％表記で、ＳｉＯ2　１０～７０％、Ｂ2Ｏ3　５～５０％、Ｌａ2Ｏ3　０～５０％、Ａｌ2Ｏ3　０～１５％、Ｌｉ2Ｏ＋Ｎａ2Ｏ＋Ｋ2Ｏ　０～２０％、ＣａＯ＋ＭｇＯ＋ＳｒＯ＋ＢａＯ　０～１５％、である。ここで、「Ｌｉ2Ｏ＋Ｎａ2Ｏ＋Ｋ2Ｏ」とは、Ｌｉ2Ｏ、Ｎａ2Ｏ、Ｋ2Ｏの合量であり、「ＣａＯ＋ＭｇＯ＋ＳｒＯ＋ＢａＯ」とは、ＣａＯ、ＭｇＯ、ＳｒＯ、ＢａＯの合量である。 The prism body 2 is made of borosilicate glass, for example. The glass composition of borosilicate glass is expressed in mol%: SiO 2 10-70%, B 2 O 3 5-50%, La 2 O 3 0-50%, Al 2 O 3 0-15%, Li 2 O + Na. 2 O+K 2 O 0-20%, CaO+MgO+SrO+BaO 0-15%. Here, "Li 2 O + Na 2 O + K 2 O" is the total amount of Li 2 O, Na 2 O, and K 2 O, and "CaO + MgO + SrO + BaO" is the total amount of CaO, MgO, SrO, and BaO. .
　プリズム本体２のガラス転移点は、７００℃以下であることが好ましい。ガラス転移点は、６００℃以下であることが好ましく、５５０℃以下であることがより好ましく、５００℃以下であることがさらに好ましい。ここで、「ガラス転移点」は、ガラス試料を粉砕し、ＤＴＡ（示差熱分析）により求めた第一変曲点の値である。 The glass transition point of the prism body 2 is preferably 700°C or lower. The glass transition point is preferably 600°C or lower, more preferably 550°C or lower, and even more preferably 500°C or lower. Here, the "glass transition point" is the value of the first inflection point obtained by crushing a glass sample and using DTA (differential thermal analysis).
　プリズム本体２の屈折率ｎｄは、好ましくは１．４以上、より好ましくは１．４５以上、更に好ましくは１．５以上、特に好ましくは１．５５以上、好ましくは１．９以下、より好ましくは１．８５以下、更に好ましくは１．８以下、特に好ましくは１．７５以下である。ここで、「屈折率ｎｄ」は、アッベ屈折率計により測定したｄ線（波長５８７．６ｎｍ）に対する屈折率の値を意味する。 The refractive index nd of the prism body 2 is preferably 1.4 or more, more preferably 1.45 or more, even more preferably 1.5 or more, particularly preferably 1.55 or more, preferably 1.9 or less, and more preferably It is 1.85 or less, more preferably 1.8 or less, particularly preferably 1.75 or less. Here, "refractive index nd" means the value of the refractive index for the d-line (wavelength 587.6 nm) measured by an Abbe refractometer.
　プリズム１は、プリズム本体２の光学機能面３、４、５のうちの少なくとも一つの表面に機能膜を有していてもよい。ここで、機能膜としては、例えば、反射防止膜、反射膜、偏光膜などが挙げられる。 The prism 1 may have a functional film on at least one of the optically functional surfaces 3, 4, and 5 of the prism body 2. Here, examples of the functional film include an antireflection film, a reflective film, and a polarizing film.
（プリズムの使用例）
　第一実施形態に係るプリズム１の使用例を図３～６に例示する。なお、プリズム１の使用例はこれらに限定されない。 (Example of prism usage)
Examples of use of the prism 1 according to the first embodiment are illustrated in FIGS. 3 to 6. Note that the usage examples of the prism 1 are not limited to these.
　図３に示す使用例では、光Ｌ１が、プリズム１のプリズム本体２の光学機能面３に照射される。光学機能面３に照射された光Ｌは、光学機能面３を透過してプリズム本体２内に入ると共に、プリズム本体２内を直進して光学機能面５で反射する。光学機能面５で反射した光Ｌは、プリズム本体２内を直進した後に光学機能面４を透過し、プリズム本体２外に出る。これにより、光Ｌ１は、プリズム１によって所定の角度（例えば９０度）に曲げられる。この場合、光学機能面３、４には、必要に応じて反射防止膜が形成される。光学機能面５の表面には、必要に応じて反射膜が形成される。 In the usage example shown in FIG. 3, the light L1 is irradiated onto the optical functional surface 3 of the prism body 2 of the prism 1. The light L irradiated onto the optically functional surface 3 passes through the optically functional surface 3 and enters the prism body 2, travels straight through the prism body 2, and is reflected by the optically functional surface 5. The light L reflected by the optical functional surface 5 travels straight through the prism body 2, passes through the optical functional surface 4, and exits the prism body 2. Thereby, the light L1 is bent by the prism 1 at a predetermined angle (for example, 90 degrees). In this case, an antireflection film is formed on the optical functional surfaces 3 and 4 as necessary. A reflective film is formed on the surface of the optically functional surface 5, if necessary.
　図４に示す使用例では、光Ｌ２、Ｌ３が、プリズム１のプリズム本体２の光学機能面３、４にそれぞれ照射される。光学機能面３に照射された光Ｌ２は、プリズム本体２内に入ることなく光学機能面３で反射する。一方、光学機能面４に照射された光Ｌ３は、プリズム本体２内に入ることなく光学機能面４で反射する。これにより、光Ｌ２、Ｌ３は、プリズム１によってそれぞれ所定の角度（例えば９０度）に曲げられる。この場合、光学機能面３、４の表面には、必要に応じて反射膜が形成される。 In the usage example shown in FIG. 4, the lights L2 and L3 are irradiated onto the optical functional surfaces 3 and 4 of the prism body 2 of the prism 1, respectively. The light L2 irradiated onto the optical functional surface 3 is reflected by the optical functional surface 3 without entering the prism body 2. On the other hand, the light L3 irradiated onto the optical functional surface 4 is reflected by the optical functional surface 4 without entering the prism body 2. Thereby, the lights L2 and L3 are each bent at a predetermined angle (for example, 90 degrees) by the prism 1. In this case, a reflective film is formed on the surfaces of the optical functional surfaces 3 and 4 as necessary.
　図５に示す使用例では、光Ｌ４が、プリズム１のプリズム本体２の光学機能面５に照射される。光学機能面５に照射された光Ｌ４は、光学機能面５を透過してプリズム本体２内に入ると共に、プリズム本体２内を直進して光学機能面３で反射する。光学機能面３で反射した光Ｌ４は、プリズム本体２内を直進して光学機能面４で反射する。光学機能面４で反射した光Ｌ４は、プリズム本体２内を直進した後に光学機能面５を透過し、プリズム本体２外に出る。これにより、光Ｌ４は、プリズム１によって所定の角度（例えば１８０度）に曲げられる。この場合、光学機能面３、４の表面には、必要に応じて反射膜が形成される。光学機能面５の表面には、必要に応じて反射防止膜が形成される。 In the usage example shown in FIG. 5, the light L4 is irradiated onto the optical functional surface 5 of the prism body 2 of the prism 1. The light L4 irradiated onto the optical functional surface 5 passes through the optical functional surface 5 and enters the prism body 2, travels straight through the prism body 2, and is reflected by the optical functional surface 3. The light L4 reflected by the optical function surface 3 travels straight through the prism body 2 and is reflected by the optical function surface 4. The light L4 reflected by the optically functional surface 4 travels straight through the prism body 2, passes through the optically functional surface 5, and exits the prism body 2. Thereby, the light L4 is bent by the prism 1 at a predetermined angle (for example, 180 degrees). In this case, a reflective film is formed on the surfaces of the optical functional surfaces 3 and 4 as necessary. An antireflection film is formed on the surface of the optically functional surface 5, if necessary.
　図６に示す使用例では、２つのプリズム１が、立方体状に組み合わされている。説明の便宜上、一方のプリズム１を第一プリズム１ｘ、他方のプリズム１を第二プリズム１ｙと呼ぶ。第一プリズム１ｘのプリズム本体２ｘの光学機能面５ｘと、第二プリズム１ｙのプリズム本体２ｙの光学機能面５ｙとが当接している。光学機能面５ｘ，５ｙの少なくとも一方の表面には、ビームスプリッター機能を有する偏光膜Ｓが形成されている。光Ｌ５は、第一プリズム１ｘのプリズム本体２ｘの光学機能面３ｘに照射される。光学機能面３ｘに照射された光Ｌ５は、光学機能面３ｘを透過してプリズム本体２ｘ内に入ると共に、プリズム本体２ｘ内を直進して偏光膜Ｓに至る。偏光膜Ｓに至った光Ｌ５の一部Ｌｐ（例えば、光Ｌに含まれるＰ偏光成分）は、偏光膜Ｓを透過する。偏光膜Ｓを透過した光Ｌｐは、第二プリズム１ｙのプリズム本体２ｙ内に入ると共に、プリズム本体２ｙ内を直進した後に光学機能面３ｙを透過してプリズム本体２ｙ外に出る。一方、偏光膜Ｓに照射された光Ｌの一部Ｌｓ（例えば、光Ｌに含まれるＳ偏光成分）は、偏光膜Ｓで反射する。偏光膜Ｓで反射した光Ｌｓは、プリズム本体２ｘ内を直進した後に光学機能面４ｘを透過してプリズム本体２ｘ外に出る。これにより、光Ｌが、２つの光Ｌｐ、Ｌｓに分離される。この場合、光学機能面３ｘ、４ｘ、３ｙ、４ｙの表面には、必要に応じて反射防止膜が形成される。 In the usage example shown in FIG. 6, two prisms 1 are combined into a cube. For convenience of explanation, one prism 1 will be referred to as a first prism 1x, and the other prism 1 will be referred to as a second prism 1y. The optically functional surface 5x of the prism body 2x of the first prism 1x is in contact with the optically functional surface 5y of the prism body 2y of the second prism 1y. A polarizing film S having a beam splitter function is formed on at least one surface of the optical functional surfaces 5x and 5y. The light L5 is irradiated onto the optically functional surface 3x of the prism body 2x of the first prism 1x. The light L5 irradiated onto the optical functional surface 3x passes through the optical functional surface 3x, enters the prism body 2x, and travels straight through the prism body 2x to reach the polarizing film S. A portion Lp of the light L5 that has reached the polarizing film S (for example, a P-polarized component included in the light L) is transmitted through the polarizing film S. The light Lp that has passed through the polarizing film S enters the prism body 2y of the second prism 1y, travels straight through the prism body 2y, passes through the optical functional surface 3y, and exits the prism body 2y. On the other hand, a portion Ls of the light L irradiated onto the polarizing film S (for example, an S-polarized component included in the light L) is reflected by the polarizing film S. The light Ls reflected by the polarizing film S travels straight through the prism body 2x, passes through the optical functional surface 4x, and exits the prism body 2x. Thereby, the light L is separated into two lights Lp and Ls. In this case, an antireflection film is formed on the surfaces of the optical functional surfaces 3x, 4x, 3y, and 4y as necessary.
（プリズムの製造方法）
　図７に示すように、第一実施形態に係るプリズム１の製造方法は、延伸成形工程Ｓ１と、プレス成型工程Ｓ２と、切断工程Ｓ３とをこの順に備える。 (Production method of prism)
As shown in FIG. 7, the method for manufacturing the prism 1 according to the first embodiment includes a stretch molding step S1, a press molding step S2, and a cutting step S3 in this order.
　図８に示すように、延伸成形工程Ｓ１では、第一ガラス部材１１を加熱しながら下方に延伸し、横断面の面積が小さい長尺な第二ガラス部材１２を得る。 As shown in FIG. 8, in the stretch forming step S1, the first glass member 11 is stretched downward while being heated to obtain a long second glass member 12 with a small cross-sectional area.
　詳細には、延伸成形工程Ｓ１では、第一ガラス部材１１の上端部を支持部１３で支持すると共に、支持部１３を下降させながら第一ガラス部材１１を加熱炉１４の内部に供給する。加熱炉１４の内部では、ヒータ１４ａによって、第一ガラス部材１１を加熱して軟化させる。加熱炉１４の下方には、軟化した第一ガラス部材１１の側面を両側から挟持する一対の延伸ローラ１５が設けられている。この一対の延伸ローラ１５によって軟化した第一ガラス部材１１を下方に延伸した後、カッター１６で所定の長さで切断することにより、第二ガラス部材１２が得られる。 Specifically, in the stretch forming step S1, the upper end of the first glass member 11 is supported by the support part 13, and the first glass member 11 is supplied into the heating furnace 14 while lowering the support part 13. Inside the heating furnace 14, the first glass member 11 is heated and softened by the heater 14a. A pair of stretching rollers 15 are provided below the heating furnace 14 to sandwich the sides of the softened first glass member 11 from both sides. After the softened first glass member 11 is stretched downward by the pair of stretching rollers 15, the second glass member 12 is obtained by cutting it to a predetermined length with the cutter 16.
　第一ガラス部材１１の加熱温度は、第一ガラス部材１１、即ちプリズム本体２のガラス転移点＋７０～１５０℃の範囲であることが好ましい。第一ガラス部材１１の下方への延伸速度（引張速度）は、１５００～３０００ｍｍ／分であることが好ましく、１８００～２７００ｍｍ／分であることがより好ましく、２０００～２５００ｍｍ／分であることがさらに好ましい。 The heating temperature of the first glass member 11 is preferably in the range of +70 to 150° C. above the glass transition point of the first glass member 11, that is, the prism body 2. The downward stretching speed (pulling speed) of the first glass member 11 is preferably 1500 to 3000 mm/min, more preferably 1800 to 2700 mm/min, and even more preferably 2000 to 2500 mm/min. preferable.
　本実施形態では、第一ガラス部材１１及び第二ガラス部材１２は、共に円柱状である。 In this embodiment, the first glass member 11 and the second glass member 12 are both cylindrical.
　第一ガラス部材１１の横断面は、円形状である。延伸前の第一ガラス部材１１の横断面の面積は、１００～１６０ｍｍ2であることが好ましく、１１０～１５０ｍｍ2であることがより好ましく、１２０～１４０ｍｍ2であることがさらに好ましい。第一ガラス部材１１は、プリズム本体２と同じガラス組成を有し、例えばホウケイ酸ガラスから形成される。 The cross section of the first glass member 11 is circular. The cross-sectional area of the first glass member 11 before stretching is preferably 100 to 160 mm 2 , more preferably 110 to 150 mm 2 , and even more preferably 120 to 140 mm 2 . The first glass member 11 has the same glass composition as the prism body 2, and is made of borosilicate glass, for example.
　第二ガラス部材１２の横断面は、円形状である。第二ガラス部材１２の横断面の面積は、延伸前の第一ガラス部材１１の横断面の面積よりも小さい。第二ガラス部材１２の横断面の面積は、０.０１１～０.０３３ｍｍ2であることが好ましく、０.０１６～０.０２６ｍｍ2であることがより好ましく、０.０１９～０.０２２ｍｍ2であることがさらに好ましい。
 The cross section of the second glass member 12 is circular. The cross-sectional area of the second glass member 12 is smaller than the cross-sectional area of the first glass member 11 before stretching. The area of the cross section of the second glass member 12 is preferably 0.011 to 0.033 mm 2 , more preferably 0.016 to 0.026 mm 2 , and more preferably 0.019 to 0.022 mm 2 . It is even more preferable that there be.
　図９～１１に示すように、プレス成型工程Ｓ２では、円柱状の長尺な第二ガラス部材１２を加熱しながらプレス成型し、三角柱状の長尺な第三ガラス部材２１を得る。 As shown in FIGS. 9 to 11, in the press molding step S2, the elongated cylindrical glass member 12 is press molded while being heated to obtain the elongated third glass member 21 in the shape of a triangular prism.
　詳細には、プレス成型工程Ｓ２では、金型２２を用いる。金型２２は、第二ガラス部材１２の側面の一部を成型する上型２３と、第二ガラス部材１２の側面の残りを成型する下型２４とを備える。上型２３は、下型２４に対して上下方向に相対移動可能である。 Specifically, a mold 22 is used in the press molding process S2. The mold 22 includes an upper mold 23 that molds a part of the side surface of the second glass member 12 and a lower mold 24 that molds the remainder of the side surface of the second glass member 12. The upper mold 23 is movable relative to the lower mold 24 in the vertical direction.
　上型２３の下面は、プリズム本体２の横断面における長辺５ａ（光学機能面５）に対応する面を成型するための平面２３ａを有する。下型２４の上面は、プリズム本体２の横断面における等辺である二つの短辺３ａ、４ａ（光学機能面３，４）に対応するそれぞれの面を成型するためのＶ字状溝２４ａを有する。Ｖ字状溝２４ａの開き角θ２は、プリズム本体２の頂角θ１と同じである。上型２３と下型２４とを閉じた状態で、平面２３ａ及びＶ字状溝２４ａによって形成される空間の横断面は、プリズム本体２の横断面と合同をなす二等辺三角形である。 The lower surface of the upper mold 23 has a flat surface 23a for molding a surface corresponding to the long side 5a (optical functional surface 5) in the cross section of the prism body 2. The upper surface of the lower mold 24 has a V-shaped groove 24a for molding respective surfaces corresponding to the two short sides 3a and 4a (optical functional surfaces 3 and 4) that are equilateral in the cross section of the prism body 2. . The opening angle θ2 of the V-shaped groove 24a is the same as the apex angle θ1 of the prism body 2. When the upper mold 23 and the lower mold 24 are closed, the cross section of the space formed by the plane 23a and the V-shaped groove 24a is an isosceles triangle that is congruent with the cross section of the prism body 2.
　プレス成型工程Ｓ２では、まず、図９及び１０に示すように、上型２３と下型２４とを開いた状態で、下型２４のＶ字状溝２４ａに第二ガラス部材１２を配置する。第二ガラス部材１２の長手方向は、Ｖ字状溝２４ａの長手方向と一致している。この状態で、第二ガラス部材１２を加熱して軟化させる。その後、図１１に示すように、上型２３及び下型２４を閉じて、第二ガラス部材１２を平面２３ａ及びＶ字状溝２４ａによってプレス成型する。これにより、円形の横断面を有する第二ガラス部材１２が変形し、三角形の横断面を有する長尺な第三ガラス部材２１が得られる。 In the press molding step S2, first, as shown in FIGS. 9 and 10, the second glass member 12 is placed in the V-shaped groove 24a of the lower mold 24 with the upper mold 23 and the lower mold 24 opened. The longitudinal direction of the second glass member 12 coincides with the longitudinal direction of the V-shaped groove 24a. In this state, the second glass member 12 is heated and softened. Thereafter, as shown in FIG. 11, the upper mold 23 and the lower mold 24 are closed, and the second glass member 12 is press-molded using the flat surface 23a and the V-shaped groove 24a. As a result, the second glass member 12 having a circular cross section is deformed, and a long third glass member 21 having a triangular cross section is obtained.
　ここで、本実施形態では、図９に示すように、下型２４のＶ字状溝２４ａの長手方向の両端部は開放している。つまり、図１１に示すように、上型２３と下型２４とを閉じてプレス成型した際に、第二ガラス部材１２の長手方向の両端部は金型２２によって拘束されない。その結果、第二ガラス部材１２をプレス成型した際に余った余剰ガラスを、第二ガラス部材１２の長手方向の両側に逃がすことができる。したがって、第二ガラス部材１２の寸法や形状のばらつきをある程度許容でき、プリズム本体２の生産性が向上する。 Here, in this embodiment, as shown in FIG. 9, both longitudinal ends of the V-shaped groove 24a of the lower die 24 are open. That is, as shown in FIG. 11, when the upper mold 23 and the lower mold 24 are closed and press-molded, both ends of the second glass member 12 in the longitudinal direction are not restrained by the mold 22. As a result, surplus glass left over when the second glass member 12 is press-molded can be released to both sides of the second glass member 12 in the longitudinal direction. Therefore, variations in size and shape of the second glass member 12 can be tolerated to some extent, and productivity of the prism body 2 is improved.
　第二ガラス部材１２の加熱温度は、第二ガラス部材１２、即ちプリズム本体２のガラス転移点＋５０～１００℃の範囲であることが好ましい。なお、第二ガラス部材１２は、例えば、金型２２を介して加熱される。金型２２は、通電加熱やヒータなどによって加熱される。 The heating temperature of the second glass member 12 is preferably in the range of +50 to 100° C. above the glass transition point of the second glass member 12, that is, the prism body 2. Note that the second glass member 12 is heated, for example, via a mold 22. The mold 22 is heated by electrical heating, a heater, or the like.
　第三ガラス部材２１の横断面の面積の好ましい範囲は、プリズム本体２の横断面の面積の好ましい範囲と同じである。 The preferred range of the cross-sectional area of the third glass member 21 is the same as the preferred range of the cross-sectional area of the prism body 2.
　第二ガラス部材１２の横断面の面積を第三ガラス部材２１の横断面の面積で除した値は、１．０１～１．１であることが好ましく、１．０２～１．０８であることがより好ましく、１．０３～１．０６であることがさらに好ましい。このようにすれば、プレス成型工程Ｓ２におけるガラスの形状変化を小さく抑えることができるため、第三ガラス部材２１を精密に加工しやすくなる。 The value obtained by dividing the cross-sectional area of the second glass member 12 by the cross-sectional area of the third glass member 21 is preferably 1.01 to 1.1, and preferably 1.02 to 1.08. is more preferable, and even more preferably 1.03 to 1.06. In this way, the change in the shape of the glass in the press molding step S2 can be suppressed to a small extent, making it easier to precisely process the third glass member 21.
　図１２に示すように、切断工程Ｓ３では、カッター３１を用いて、第三ガラス部材２１を所定の長さで切断し、複数のプリズム本体２を得る。本実施形態では、第三ガラス部材２１は、０．２５ｍｍ以下の長さで切断される。なお、第三ガラス部材２１の長手方向の両端部は廃棄され、第三ガラス部材２１の長手方向の中央部からプリズム本体２が採取される。 As shown in FIG. 12, in the cutting step S3, the third glass member 21 is cut to a predetermined length using the cutter 31 to obtain a plurality of prism bodies 2. In this embodiment, the third glass member 21 is cut to a length of 0.25 mm or less. Note that both ends of the third glass member 21 in the longitudinal direction are discarded, and the prism body 2 is collected from the central part of the third glass member 21 in the longitudinal direction.
　以上のような製造方法にすれば、延伸成形工程Ｓ１によって、横断面の面積が非常に小さい第二ガラス部材１２を容易に成形できる。加えて、第二ガラス部材１２の側面は、火造り面からなる平滑面となる。そして、プレス成型工程Ｓ２によって、第二ガラス部材１２を、プリズム本体２の断面形状と一致する断面を有する第三ガラス部材２１に仕上げ加工できる。この際、第三ガラス部材２１の側面も、第二ガラス部材１２の側面に準じた平滑面となるため、未研磨の状態でも、光学機能面として十分に機能する。したがって、切断工程Ｓ３で第三ガラス部材２１を切断することで、微小なプリズム本体２を安定的に得ることができる。つまり、このプリズム本体２を用いれば、微小なプリズム１を容易に製造できる。 With the above manufacturing method, the second glass member 12 having a very small cross-sectional area can be easily formed by the stretch forming step S1. In addition, the side surface of the second glass member 12 is a smooth surface made of a fire-finished surface. Then, in the press molding step S2, the second glass member 12 can be finished into the third glass member 21 having a cross section that matches the cross-sectional shape of the prism body 2. At this time, since the side surface of the third glass member 21 also becomes a smooth surface similar to the side surface of the second glass member 12, it functions sufficiently as an optically functional surface even in an unpolished state. Therefore, by cutting the third glass member 21 in the cutting step S3, a minute prism main body 2 can be stably obtained. In other words, by using this prism body 2, a minute prism 1 can be easily manufactured.
　また、第一ガラス部材１１中に泡が含まれていても、延伸成形工程Ｓ１でその泡が引き延ばされる。その結果、プリズム本体２の横断面に泡が含まれにくくなり、仮に含まれていたとしても、プリズム１の光学特性に影響を与えない非常に小さなものとなる利点がある。 Furthermore, even if bubbles are included in the first glass member 11, the bubbles are stretched in the stretch forming step S1. As a result, bubbles are less likely to be included in the cross section of the prism body 2, and even if bubbles are included, there is an advantage that the bubbles are very small and do not affect the optical characteristics of the prism 1.
＜第二実施形態＞
（ガラス物品）
　図１３に示すように、第二実施形態に係るガラス物品４１は、レンズ部４２を備えるプリズム１と、ガラスロッド４３とを備える。 <Second embodiment>
(Glass articles)
As shown in FIG. 13, a glass article 41 according to the second embodiment includes a prism 1 including a lens portion 42 and a glass rod 43.
　レンズ部４２は、凸状又は凹状の曲面レンズが含まれる。曲面レンズには、球面レンズ、非球面レンズ、シリンドリカルレンズなどが含まれる。本実施形態では、レンズ部４２が、非球面凸レンズである場合を例示する。 The lens portion 42 includes a convex or concave curved lens. Curved lenses include spherical lenses, aspheric lenses, cylindrical lenses, and the like. In this embodiment, the case where the lens portion 42 is an aspherical convex lens will be exemplified.
　レンズ部４２は、プリズム本体２の光学機能面３（断面における短辺３ａに相当）に設けられている。本実施形態では、レンズ部４２は、プリズム本体２と一体成形されており、レンズ部４２とプリズム本体２との間には、両者を接合するための接着層が介在していない。したがって、レンズ部４２は、プリズム本体２と同じガラス材料（例えば、ホウケイ酸ガラス）で形成されている。なお、レンズ部４２とプリズム本体２とを別体で構成し、両者を接着剤で接合してもよい。 The lens portion 42 is provided on the optically functional surface 3 (corresponding to the short side 3a in the cross section) of the prism body 2. In this embodiment, the lens portion 42 is integrally molded with the prism body 2, and there is no adhesive layer interposed between the lens portion 42 and the prism body 2 to bond them together. Therefore, the lens portion 42 is made of the same glass material as the prism body 2 (for example, borosilicate glass). In addition, the lens part 42 and the prism main body 2 may be constructed as separate bodies, and both may be joined with an adhesive.
　本実施形態では、プリズム本体２の光学機能面３（断面における短辺３ａに相当）と、光学機能面４（断面における短辺４ａに相当）との間の光路上に位置する光学機能面５（断面における長辺５ａに相当）には、反射膜４４が形成されている。なお、反射膜４４は形成しなくてもよい。 In this embodiment, an optical functional surface 5 is located on the optical path between the optical functional surface 3 (corresponding to the short side 3a in the cross section) of the prism body 2 and the optical functional surface 4 (corresponding to the short side 4a in the cross section). A reflective film 44 is formed on the long side 5a (corresponding to the long side 5a in the cross section). Note that the reflective film 44 may not be formed.
　ガラスロッド４３は、棒状のガラス部材である。本実施形態では、ガラスロッド４３が、円柱状のガラス部材である場合を例示する。 The glass rod 43 is a rod-shaped glass member. In this embodiment, a case is illustrated in which the glass rod 43 is a cylindrical glass member.
　ガラスロッド４３は、プリズム本体２と同じガラス材料（例えば、ホウケイ酸ガラス）で形成されていることが好ましい。 It is preferable that the glass rod 43 is made of the same glass material as the prism body 2 (for example, borosilicate glass).
　ガラスロッド４３の長手方向の一方の端面４３ａは、プリズム本体２の光学機能面４に接着層４５を介して接合されている。ガラスロッド４３の端面４３ａの面積は、例えば、０．０７～０．２ｍｍ2である。ガラスロッド４３の長手方向の寸法Ｘ５は、例えば、０.３～１ｍｍである。プリズム１にレンズ部４２を設けることにより、ガラスロッド４３にレンズ機能を付与しなくて済むため、ガラスロッド４３の長手方向の寸法Ｘ５を短くできる。つまり、ガラス物品４１の小型化を図ることができる。 One longitudinal end surface 43a of the glass rod 43 is bonded to the optically functional surface 4 of the prism body 2 via an adhesive layer 45. The area of the end surface 43a of the glass rod 43 is, for example, 0.07 to 0.2 mm 2 . The longitudinal dimension X5 of the glass rod 43 is, for example, 0.3 to 1 mm. By providing the lens portion 42 in the prism 1, it is not necessary to provide the glass rod 43 with a lens function, so that the longitudinal dimension X5 of the glass rod 43 can be shortened. In other words, the glass article 41 can be made smaller.
　ガラスロッド４３と接着層４５との屈折率差は、０～０．４であることが好ましい。接着層４５とプリズム本体２との屈折率差は、０～０．４であることが好ましい。ガラスロッド４３と接着層４５との屈折率差や、接着層４５とプリズム本体２との屈折率差は、各部材２、４３、４５の屈折率の値から算出できる。 The difference in refractive index between the glass rod 43 and the adhesive layer 45 is preferably 0 to 0.4. The difference in refractive index between the adhesive layer 45 and the prism body 2 is preferably 0 to 0.4. The refractive index difference between the glass rod 43 and the adhesive layer 45 and the refractive index difference between the adhesive layer 45 and the prism body 2 can be calculated from the refractive index values of each member 2, 43, and 45.
　ガラスロッド４３及び接着層４５のそれぞれの屈折率ｎｄは、好ましくは１．４以上、より好ましくは１．４５以上、更に好ましくは１．５以上、特に好ましくは１．５５以上、好ましくは１．９以下、より好ましくは１．８５以下、更に好ましくは１．８以下、特に好ましくは１．７５以下である。 The refractive index nd of each of the glass rod 43 and the adhesive layer 45 is preferably 1.4 or more, more preferably 1.45 or more, even more preferably 1.5 or more, particularly preferably 1.55 or more, and preferably 1. It is 9 or less, more preferably 1.85 or less, even more preferably 1.8 or less, particularly preferably 1.75 or less.
　図１４に示すように、ガラスロッド４３の端面４３ａをその直交方向から見た場合に、プリズム本体２及びレンズ部４２が、端面４３ａの外側に食み出していない。プリズム本体２の光学機能面４の面積Ｐと端面４３ａの面積Ｑとの比Ｐ／Ｑは、０．９５以下であることが好ましい。このようにすれば、ガラスロッド４３の端面４３ａの周縁部がプリズム本体２及びレンズ部４２よりも外側に位置するため、プリズム本体２及びレンズ部４２が他部材と接触するのを抑制できる。 As shown in FIG. 14, when the end surface 43a of the glass rod 43 is viewed from the orthogonal direction, the prism body 2 and the lens portion 42 do not protrude outside the end surface 43a. The ratio P/Q of the area P of the optically functional surface 4 of the prism body 2 to the area Q of the end surface 43a is preferably 0.95 or less. In this way, the peripheral edge of the end surface 43a of the glass rod 43 is located outside the prism body 2 and the lens part 42, so that it is possible to suppress the prism body 2 and the lens part 42 from coming into contact with other members.
　以上のように構成されたガラス物品４１では、例えば、ガラスロッド４３の長手方向の一方側の端面４３ｂからガラスロッド４３中に入射した光Ｌ６が、ガラスロッド４３内を伝搬した後に、ガラスロッド４３の長手方向の他方の端面４３ａからプリズム本体２の光学機能面４を介してプリズム本体２内に入射する。プリズム本体２内に入射した光Ｌ６は、プリズム本体２の光学機能面５に形成された反射膜４４によって光学機能面３側に反射され、レンズ部４２によって集光される。集光された光Ｌ６は、所定の対象物４６に照射され、対象物４６からの反射光が、光Ｌ６と同様の光路を逆向きに伝搬し、ガラスロッド４３の端面４３ｂに戻ってくる。 In the glass article 41 configured as described above, for example, the light L6 incident on the glass rod 43 from the end surface 43b on one side in the longitudinal direction of the glass rod 43 propagates inside the glass rod 43, and then the light L6 enters the glass rod 43. The light enters the prism body 2 from the other end surface 43a in the longitudinal direction via the optical functional surface 4 of the prism body 2. The light L6 that has entered the prism body 2 is reflected toward the optical function surface 3 by the reflective film 44 formed on the optical function surface 5 of the prism body 2, and is focused by the lens portion 42. The focused light L6 is irradiated onto a predetermined object 46, and the reflected light from the object 46 propagates in the opposite direction along the same optical path as the light L6 and returns to the end surface 43b of the glass rod 43.
　そして、ガラスロッド４３の端面４３ｂに戻ってきた反射光を、光ファイバーなどを介して所定の計測装置に取り込んで解析すれば、対象物４６の状況を把握できる。そのため、ガラス物品４１は、例えば、血管内ＯＣＴ（Optical Coherence Tomography（光干渉断層撮影））に利用される。この場合、例えば、光Ｌ６としては赤外線が利用され、対象物４６は血管の内壁などとなる。 Then, the state of the object 46 can be grasped by capturing the reflected light that has returned to the end surface 43b of the glass rod 43 into a predetermined measuring device via an optical fiber or the like and analyzing it. Therefore, the glass article 41 is used, for example, in intravascular OCT (Optical Coherence Tomography). In this case, for example, infrared rays are used as the light L6, and the target object 46 is the inner wall of a blood vessel.
（ガラス物品の製造方法）
　図１５に示すように、第二実施形態に係るガラス物品４１の製造方法は、レンズ部４２を備えるプリズム１を準備する第一準備工程Ｓ４と、ガラスロッド４３を準備する第二準備工程Ｓ５と、プリズム１のプリズム本体２とガラスロッド４３とを接合する接合工程Ｓ６とを備える。第一準備工程Ｓ４及び第二準備工程Ｓ５は、いずれを先に行ってもよいし、同時に行ってもよい。 (Method for manufacturing glass articles)
As shown in FIG. 15, the method for manufacturing a glass article 41 according to the second embodiment includes a first preparation step S4 in which a prism 1 including a lens portion 42 is prepared, and a second preparation step S5 in which a glass rod 43 is prepared. , and a joining step S6 of joining the prism body 2 of the prism 1 and the glass rod 43. Either of the first preparation step S4 and the second preparation step S5 may be performed first, or they may be performed simultaneously.
　第一準備工程Ｓ４では、第一実施形態で説明したように、延伸成形工程Ｓ１と、プレス成型工程Ｓ２と、切断工程Ｓ３とをこの順に実施し、プリズム本体２を得る。第二実施形態が第一実施形態と異なる点は、図１６に示すように、プレス成型工程Ｓ２において、第三ガラス部材２１をプレス成型する際に、第三ガラス部材２１の一つの側面に、長手方向に間隔を置いて複数のレンズ部４２も同時に一体的に成型する点である。そのため、図１７及び図１８に示すように、切断工程Ｓ３では、複数のレンズ部４２を備える第三ガラス部材２１を所定の長さで切断することで、レンズ部４２を一体的に備えたプリズム本体２を簡単に得ることができる。なお、第三ガラス部材２１の一つの側面に成型するレンズ部４２の個数は、複数であることに限定されず、１つでも構わない。 In the first preparation step S4, as described in the first embodiment, the stretch molding step S1, the press molding step S2, and the cutting step S3 are performed in this order to obtain the prism body 2. The second embodiment is different from the first embodiment, as shown in FIG. The point is that a plurality of lens portions 42 are simultaneously and integrally molded at intervals in the longitudinal direction. Therefore, as shown in FIGS. 17 and 18, in the cutting step S3, the third glass member 21 including the plurality of lens parts 42 is cut to a predetermined length, thereby forming a prism integrally provided with the lens parts 42. The main body 2 can be easily obtained. Note that the number of lens portions 42 molded on one side surface of the third glass member 21 is not limited to a plurality, and may be one.
　第二準備工程Ｓ５では、リドロー法などによりガラスロッド４３を得る。 In the second preparation step S5, a glass rod 43 is obtained by a redraw method or the like.
　接合工程Ｓ６では、レンズ部４２を備えたプリズム１のプリズム本体２と、ガラスロッド４３とを接着層４５を介して接合する。これにより、ガラス物品１を得ることができる。 In the bonding step S6, the prism body 2 of the prism 1 including the lens portion 42 and the glass rod 43 are bonded via the adhesive layer 45. Thereby, the glass article 1 can be obtained.
　なお、本発明は、上記の実施形態の構成に限定されるものではなく、上記した作用効果に限定されるものでもない。本発明は、本発明の要旨を逸脱しない範囲で種々の変更が可能である。 Note that the present invention is not limited to the configuration of the embodiments described above, nor is it limited to the effects described above. The present invention can be modified in various ways without departing from the gist of the invention.
　上記の実施形態において、プレス成型工程の後かつ切断工程の前に、第三ガラス部材の側面に機能膜を形成する成膜工程を実施してもよい。このようにすれば、第三ガラス部材を切断して得られるプリズム本体に個別に機能膜を形成する場合に比べて、成膜工程を容易に行うことができる。 In the embodiment described above, a film forming process may be performed to form a functional film on the side surface of the third glass member after the press molding process and before the cutting process. In this way, the film forming process can be performed more easily than when the functional film is individually formed on the prism body obtained by cutting the third glass member.
　上記の実施形態では、第三ガラス部材及びプリズム本体が三角柱である場合を説明したが、第三ガラス部材及びプリズム本体は三角柱以外の多角柱であってもよい。 In the above embodiment, a case has been described in which the third glass member and the prism body are triangular prisms, but the third glass member and the prism body may be polygonal prisms other than triangular prisms.
　上記の実施形態では、延伸成形工程で成形された第二ガラス部材が円柱状である場合を説明したが、第二ガラス部材は、プリズム本体の横断面と略相似形状をなす横断面を有する多角柱（例えば三角柱）であってもよい。このようにすれば、プレス成型工程における第二ガラス部材の変形量がより少なくなるため、プリズム本体の成型安定性が向上する。この場合、多角柱状の第二ガラス部材は、例えば、第二ガラス部材の横断面と略相似形状をなす横断面を有する多角柱状の第一ガラス部材を延伸成形することにより得ることができる。 In the above embodiment, the second glass member formed in the stretch forming process is cylindrical. It may be a prism (for example, a triangular prism). In this way, the amount of deformation of the second glass member during the press molding process is reduced, so that the molding stability of the prism body is improved. In this case, the polygonal column-shaped second glass member can be obtained, for example, by stretch-molding a polygonal column-shaped first glass member having a cross section that is substantially similar to the cross section of the second glass member.
　以下、本発明に係るガラス物品について実施例に基づいて説明する。なお、以下の実施例は単なる例示であって、本発明は、以下の実施例に何ら限定されない。 Hereinafter, the glass article according to the present invention will be explained based on Examples. Note that the following examples are merely illustrative, and the present invention is not limited to the following examples in any way.
　本発明の効果を確かめるために、異なる方法により、横断面が直角二等辺三角形をなす三角柱状のプリズム本体１０００個を製造し、それぞれのプリズム本体中の泡の有無及び量産性を評価した。その結果を表１に示す。 In order to confirm the effects of the present invention, 1000 triangular prism bodies having a right isosceles triangle cross section were manufactured using different methods, and the presence or absence of bubbles in each prism body and mass productivity were evaluated. The results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　実施例１では、図８～１２に示したように、延伸成形により得られた円柱状のプリフォーム（第二ガラス部材に相当）をプレス成型することにより三角柱状のガラス部材（第三ガラス部材に相当）に成型した後、そのガラス部材を所定の長さで切断してプリズム本体を製造することを試みた。この際、一例を挙げると、円柱状のプリフォーム（第二ガラス部材）の横断面の面積は、０．０３１ｍｍ2であった。また、円柱状のプリフォーム（第二ガラス部材）の横断面の面積を三角柱状のガラス部材（第三ガラス部材）の横断面の面積で除した値は、１．０４であった。 In Example 1, as shown in FIGS. 8 to 12, a cylindrical preform (corresponding to the second glass member) obtained by stretch molding is press-molded to form a triangular prism-shaped glass member (third glass member). We attempted to manufacture a prism body by cutting the glass member into a predetermined length. In this case, to give an example, the cross-sectional area of the cylindrical preform (second glass member) was 0.031 mm 2 . Further, the value obtained by dividing the cross-sectional area of the cylindrical preform (second glass member) by the cross-sectional area of the triangular prism-shaped glass member (third glass member) was 1.04.
　一方、比較例１では、球状のゴブをプレス成型により三角柱状のガラス部材に成型した後、そのガラス部材を所定の長さで切断してプリズム本体を製造することを試みた。比較例２では、所定形状のゴブを研磨することにより三角柱状のガラス部材を形成した後、そのガラス部材を所定の長さで切断してプリズム本体を製造することを試みた。 On the other hand, in Comparative Example 1, an attempt was made to manufacture a prism body by molding a spherical gob into a triangular prism-shaped glass member by press molding, and then cutting the glass member to a predetermined length. In Comparative Example 2, an attempt was made to form a triangular prism-shaped glass member by polishing a gob of a predetermined shape, and then cut the glass member to a predetermined length to manufacture a prism body.
　実施例１、比較例１～２で用いるプリフォームは、ガラス組成として、モル％で、ＳｉＯ2　５０％、Ｂ2Ｏ3　２０％、Ｌａ2Ｏ3　１５％、ＺｎＯ　５％、Ａｌ2Ｏ3　５％、Ｎａ2Ｏ　５％を含有するホウケイ酸ガラスを用いた。 The preforms used in Example 1 and Comparative Examples 1 and 2 had a glass composition, in terms of mol%, of 50% SiO 2 , 20% B 2 O 3 , 15% La 2 O 3 , 5% ZnO, and Al 2 O 3 Borosilicate glass containing 5% Na 2 O and 5% Na 2 O was used.
　プリズム本体中の泡の有無は、光学顕微鏡（５０倍）を用いて観測した。 The presence or absence of bubbles in the prism body was observed using an optical microscope (50x magnification).
　プリズム本体の量産性は、「○」、「△」、「×」の三段階で判定した。「○」は、得られた高品質のプリズム本体が、９００個以上だったことを意味する。「△」は、得られた高品質のプリズム本体が、５００～８９９個だったことを意味する。「×」は、得られた高品質のプリズム本体が、５００個未満だったことを意味する。ここで、高品質とは、プリズム本体の横断面の短辺が所定の長さであり、光学特性に影響を及ぼすような割れやチッピングがなかったことを意味する。 The mass productivity of the prism body was judged in three stages: "○", "△", and "×". "○" means that the number of high quality prism bodies obtained was 900 or more. "Δ" means that the number of high quality prism bodies obtained was 500 to 899. "X" means that less than 500 high quality prism bodies were obtained. Here, high quality means that the short side of the cross section of the prism body has a predetermined length, and there is no cracking or chipping that would affect optical properties.
　表１からも分かるように、実施例１では、横断面における短辺の長さが０．２５ｍｍ以下（横断面の面積は０．０３２ｍｍ2以下）となる微小なプリズム本体でも良好に量産できた。一方、比較例１では、横断面における短辺の長さが０．３０ｍｍ以下となるプリズム本体は製造できなかった。また、比較例２では、横断面における短辺の長さが小さくなるに連れてプリズム本体の量産性が悪化し、横断面における短辺の長さが０．２５ｍｍ以下（横断面の面積は０．０３２ｍｍ2以下）となる微小なプリズム本体は製造できなかった。 As can be seen from Table 1, in Example 1, even a small prism body with a short side length of 0.25 mm or less in the cross section (the area of the cross section was 0.032 mm 2 or less) could be successfully mass-produced. . On the other hand, in Comparative Example 1, it was not possible to manufacture a prism body in which the length of the short side in the cross section was 0.30 mm or less. In addition, in Comparative Example 2, as the length of the short side in the cross section becomes smaller, the mass productivity of the prism body deteriorates. It was not possible to manufacture a small prism body with a diameter of .032 mm 2 or less.
　また、実施例１では、プリズム本体中に泡が確認されなかったのに対し、比較例１及び２では、それぞれ泡が確認された。泡はプリズムの光学特性に悪影響を与えるおそれがある。したがって、実施例１に係るプリズムは、比較例に係るプリズムよりも光学特性が良好となる。 Further, in Example 1, no bubbles were observed in the prism body, whereas in Comparative Examples 1 and 2, bubbles were observed in each. Bubbles can adversely affect the optical properties of the prism. Therefore, the prism according to Example 1 has better optical characteristics than the prism according to the comparative example.
１　　　　　　　　プリズム
２　　　　　　　　プリズム本体
３、４、５　　　　光学機能面
３ａ、４ａ　　　　短辺
５ａ　　　　　　　長辺
６、７、８　　　　接続面
６ａ、７ａ、８ａ　接続線
９、１０　　　　　端面
１１　　　　　　　第一ガラス部材
１２　　　　　　　第二ガラス部材
１３　　　　　　　支持部
１４　　　　　　　加熱炉
１４ａ　　　　　　ヒータ
１５　　　　　　　延伸ローラ
１６　　　　　　　カッター
２１　　　　　　　第三ガラス部材
２２　　　　　　　金型
２３　　　　　　　上型
２３ａ　　　　　　平面（成型面）
２４　　　　　　　下型
２４ａ　　　　　　Ｖ字状溝（成型面）
３１　　　　　　　カッター
４１　　　　　　　ガラス物品
４２　　　　　　　レンズ部
４３　　　　　　　ガラスロッド
４４　　　　　　　反射膜
４５　　　　　　　接着層
Ｓ１　　　　　　　延伸成形工程
Ｓ２　　　　　　　プレス成型工程
Ｓ３　　　　　　　切断工程
Ｓ４　　　　　　　第一準備工程
Ｓ５　　　　　　　第二準備工程
Ｓ６　　　　　　　接合工程 1 Prism 2 Prism body 3, 4, 5 Optical functional surface 3a, 4a Short side 5a Long side 6, 7, 8 Connection surface 6a, 7a, 8a Connection wire 9, 10 End surface 11 First glass member 12 Second glass member 13 Support part 14 Heating furnace 14a Heater 15 Stretching roller 16 Cutter 21 Third glass member 22 Mold 23 Upper mold 23a Plane (molding surface)
24 Lower mold 24a V-shaped groove (molding surface)
31 Cutter 41 Glass article 42 Lens portion 43 Glass rod 44 Reflective film 45 Adhesive layer S1 Stretch molding process S2 Press molding process S3 Cutting process S4 First preparation process S5 Second preparation process S6 Bonding process

Claims (17)

  1. 　複数の光学機能面を側面に有する多角柱状のガラス製プリズム本体を備えるプリズムであって、
    　前記プリズム本体が、多角形状の横断面を有し、
    　前記横断面の面積が、０．０３２ｍｍ2以下であり、
    　前記横断面を区画する複数の辺のうち少なくとも一辺の長さが、０．２５ｍｍ以下であることを特徴とするプリズム。     A prism comprising a polygonal columnar glass prism body having a plurality of optically functional surfaces on its sides,
    the prism body has a polygonal cross section;
    The area of the cross section is 0.032 mm 2 or less,
    A prism characterized in that the length of at least one of the plurality of sides defining the cross section is 0.25 mm or less.
  2. 　前記光学機能面の表面粗さＲａが、５０ｎｍ以下である請求項１に記載のプリズム。 The prism according to claim 1, wherein the optical functional surface has a surface roughness Ra of 50 nm or less.
  3. 　前記プリズム本体は、ガラス転移点が７００℃以下、かつ、屈折率ｎｄが１．４～１．９であるホウケイ酸ガラスから形成される請求項１又は２に記載のプリズム。 The prism according to claim 1 or 2, wherein the prism body is formed from borosilicate glass having a glass transition point of 700° C. or less and a refractive index nd of 1.4 to 1.9.
  4. 　前記横断面が、二等辺三角形である請求項１又は２に記載のプリズム。 The prism according to claim 1 or 2, wherein the cross section is an isosceles triangle.
  5. 　前記プリズム本体の前記光学機能面にレンズ部を備える請求項１又は２に記載のプリズム。 The prism according to claim 1 or 2, further comprising a lens portion on the optically functional surface of the prism body.
  6. 　前記プリズム本体と前記レンズ部とが一体成型されてなる請求項５に記載のプリズム。 The prism according to claim 5, wherein the prism body and the lens portion are integrally molded.
  7. 　請求項５に記載のプリズムと、ガラスロッドとを備え、
    　前記ガラスロッドの端面が、前記レンズ部が設けられた前記光学機能面とは別の前記光学機能面に接合されていることを特徴とするガラス物品。     comprising the prism according to claim 5 and a glass rod,
    A glass article characterized in that an end surface of the glass rod is joined to the optically functional surface that is different from the optically functional surface on which the lens portion is provided.
  8. 　前記ガラスロッドが接合された前記光学機能面と、前記レンズ部が設けられた前記光学機能面との間の光路上に位置する前記光学機能面に反射膜が設けられている請求項７に記載のガラス物品。 8. A reflective film is provided on the optical functional surface located on the optical path between the optical functional surface to which the glass rod is bonded and the optical functional surface to which the lens portion is provided. glass articles.
  9. 　前記プリズム本体の前記端面を、前記端面と直交する方向から見た場合に、前記プリズム本体及び前記レンズ部が、前記端面の外側に食み出さない請求項７又は８に記載のガラス物品。 The glass article according to claim 7 or 8, wherein the prism body and the lens portion do not protrude outside the end face when the end face of the prism body is viewed from a direction perpendicular to the end face.
  10. 　前記ガラスロッドが、接着層を介して前記プリズム本体に接合されており、
    　前記ガラスロッドと前記接着層との屈折率差が、０～０．４であり、
    　前記接着層と前記プリズム本体との屈折率差が、０～０．４である請求項７又は８に記載のガラス物品。     The glass rod is bonded to the prism body via an adhesive layer,
    The refractive index difference between the glass rod and the adhesive layer is 0 to 0.4,
    The glass article according to claim 7 or 8, wherein the difference in refractive index between the adhesive layer and the prism body is 0 to 0.4.
  11. 　複数の光学機能面を側面に有する多角柱状のガラス製プリズム本体を備えるプリズムの製造方法であって、
    　第一ガラス部材を加熱しながら延伸成形し、長尺な第二ガラス部材を得る延伸成形工程と、
    　前記第二ガラス部材を加熱しながらプレス成型し、多角柱状の長尺な第三ガラス部材を得るプレス成型工程と、
    　前記第三ガラス部材を所定の長さで切断し、前記プリズム本体を得る切断工程と、を備え、
    　前記第三ガラス部材が、多角形状の横断面を有し、前記横断面の面積が、０．０３２ｍｍ2以下であり、前記横断面を区画する複数の辺のうち少なくとも一辺の長さが、０．２５ｍｍ以下であることを特徴とするプリズムの製造方法。     A method for manufacturing a prism comprising a polygonal columnar glass prism body having a plurality of optically functional surfaces on its side surfaces, the method comprising:
    Stretching and molding the first glass member while heating it to obtain a long second glass member;
    Press-molding the second glass member while heating it to obtain a polygonal prism-shaped elongated third glass member;
    a cutting step of cutting the third glass member to a predetermined length to obtain the prism body;
    The third glass member has a polygonal cross section, the area of the cross section is 0.032 mm 2 or less, and the length of at least one side of the plurality of sides defining the cross section is 0. A method for manufacturing a prism, characterized in that the prism is 25 mm or less.
  12. 　前記第二ガラス部材の横断面の面積を前記第三ガラス部材の横断面の面積で除した値が、１．０１～１．１である請求項１１に記載のプリズムの製造方法。 The method for manufacturing a prism according to claim 11, wherein a value obtained by dividing the cross-sectional area of the second glass member by the cross-sectional area of the third glass member is 1.01 to 1.1.
  13. 　前記第二ガラス部材の横断面の面積が、０．０３６ｍｍ2以下である請求項１１又は１２に記載のプリズムの製造方法。 The method for manufacturing a prism according to claim 11 or 12, wherein the cross-sectional area of the second glass member is 0.036 mm 2 or less.
  14. 　前記第二ガラス部材が、円柱状である請求項１１又は１２に記載のプリズムの製造方法。 The method for manufacturing a prism according to claim 11 or 12, wherein the second glass member has a cylindrical shape.
  15. 　前記第三ガラス部材の前記横断面が、二等辺三角形である請求項１１又は１２に記載のプリズムの製造方法。 The method for manufacturing a prism according to claim 11 or 12, wherein the cross section of the third glass member is an isosceles triangle.
  16. 　前記プレス成型工程では、前記第二ガラス部材の長手方向の両端部を拘束しない状態でプレス成型する請求項１１又は１２に記載のプリズムの製造方法。 The prism manufacturing method according to claim 11 or 12, wherein in the press molding step, press molding is performed in a state where both ends of the second glass member in the longitudinal direction are not restrained.
  17. 　前記切断工程の前に、前記第三ガラス部材の側面に機能膜を形成する成膜工程を備える請求項１１又は１２に記載のプリズムの製造方法。 The method for manufacturing a prism according to claim 11 or 12, further comprising a film forming step of forming a functional film on a side surface of the third glass member before the cutting step.
PCT/JP2023/027060 2022-09-02 2023-07-24 Prism, glass article, and method for manufacturing prism WO2024048127A1 (en)

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH101321A (en) * 1996-06-18 1998-01-06 Hooya Precision Kk Production of optical element
JP2003329817A (en) * 2002-03-08 2003-11-19 Nippon Electric Glass Co Ltd Prism and method for producing the same
JP2006069886A (en) * 2004-09-03 2006-03-16 Schott Ag Micro prism, micro rod lens and method and apparatus for producing them
WO2007026776A1 (en) * 2005-08-30 2007-03-08 Mitsubishi Rayon Co., Ltd. Light deflection sheet and its manufacturing method
JP2008145482A (en) * 2006-12-06 2008-06-26 Epson Toyocom Corp Manufacturing method of right-angled triangular prism
JP2011128176A (en) * 2009-12-15 2011-06-30 Nippon Electric Glass Co Ltd Optical component and method of manufacturing the same
JP2011170224A (en) * 2010-02-22 2011-09-01 Konica Minolta Opto Inc Method for manufacturing optical element
WO2018186123A1 (en) * 2017-04-03 2018-10-11 オリンパス株式会社 Endoscope system and adjustment method for endoscope system

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH101321A (en) * 1996-06-18 1998-01-06 Hooya Precision Kk Production of optical element
JP2003329817A (en) * 2002-03-08 2003-11-19 Nippon Electric Glass Co Ltd Prism and method for producing the same
JP2006069886A (en) * 2004-09-03 2006-03-16 Schott Ag Micro prism, micro rod lens and method and apparatus for producing them
WO2007026776A1 (en) * 2005-08-30 2007-03-08 Mitsubishi Rayon Co., Ltd. Light deflection sheet and its manufacturing method
JP2008145482A (en) * 2006-12-06 2008-06-26 Epson Toyocom Corp Manufacturing method of right-angled triangular prism
JP2011128176A (en) * 2009-12-15 2011-06-30 Nippon Electric Glass Co Ltd Optical component and method of manufacturing the same
JP2011170224A (en) * 2010-02-22 2011-09-01 Konica Minolta Opto Inc Method for manufacturing optical element
WO2018186123A1 (en) * 2017-04-03 2018-10-11 オリンパス株式会社 Endoscope system and adjustment method for endoscope system

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