Light guide plate and method for manufacturing the same

Abstract

The present invention provides a method for manufacturing a light guide plate that can efficiently extract the desired light and increase productivity. [Solution] A method for manufacturing a light guide plate having a black support portion and a light guide portion, comprising the steps of: preparing a molding member 11 having a support base material 12 made of black glass and a light guide portion forming portion 13; heating and stretching the molding member 11 to obtain a light guide plate base material 11A; and cutting the light guide plate base material 11A to obtain a light guide plate.

Description

[Technical Field]

[0001] This invention relates to a light guide plate and a method for manufacturing the light guide plate. [Background technology]

[0002] Light-sheet microscopes are known as microscopes for observing cross-sections of biological tissues and cells (for example, Patent Document 1). In light-sheet microscopes, light is irradiated from the side of the sample, so adverse effects on cells and other tissues can be reduced compared to microscopes that irradiate light from the front of the sample. In addition, light-sheet microscopes are suitable for obtaining three-dimensional images by relatively moving a sheet of light (light sheet) up and down.

[0003] Light-sheet microscopes are considered expensive because they use special optical elements to project a light sheet onto the object being observed. Therefore, as a way to obtain a light sheet at a lower cost, a method has been investigated in which light is incident from the edge of a glass plate (hereinafter referred to as a glass sheet) to obtain a sheet of light (for example, Patent Document 2).

[0004] Patent Document 2 discloses a light guide plate comprising a glass sheet and a support member for supporting the glass sheet. Patent Document 2 states that by providing a light absorbing portion on the main surface of the glass sheet that absorbs light other than parallel light directly transmitted through the glass sheet, it is possible to selectively emit high-quality light from the edge of the glass sheet. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2018-17970 [Patent Document 2] International Publication No. 2024 / 171736 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, when supporting a thin glass sheet with a support member in a light guide plate, it is necessary to join the support member and the glass sheet using an adhesive or other bonding material. However, when the support member and the glass sheet are joined with a bonding material, light loss may occur at the boundary between the support member and the glass sheet. Furthermore, when joining the support member and the glass sheet with a bonding material, alignment of each component is also necessary, making it difficult to sufficiently improve productivity. In addition, when an adhesive such as resin is used between the support member and the glass sheet, the heat resistance and durability of the light guide plate may decrease due to the deterioration of the adhesive.

[0007] The object of the present invention is to provide a light guide plate and a method for manufacturing the light guide plate that can efficiently extract desired light and increase productivity. [Means for solving the problem]

[0008] This document describes various embodiments of a light guide plate and a method for manufacturing the light guide plate that solve the above problems.

[0009] A method for manufacturing a light guide plate according to Embodiment 1 of the present invention is a method for manufacturing a light guide plate having a black support portion and a light guide portion, characterized by comprising the steps of: preparing a molding member having a support base material made of black glass and a light guide portion forming portion; heating and stretching the molding member to obtain a light guide plate base material; and cutting the light guide plate base material to obtain a light guide plate. In the method for manufacturing a light guide plate according to Embodiment 1, a light guide plate can be easily manufactured by heating and stretching a molding member having a support base material made of black glass and a light guide portion forming portion. Furthermore, according to this manufacturing method, a light guide plate in which the support portion and the light guide portion are integrated can be obtained, so there is no need to provide a bonding material such as an adhesive between the support portion and the light guide portion. Therefore, light loss is less likely to occur at the boundary between the support portion and the light guide portion, as is the case when a bonding material such as an adhesive is provided between the support portion and the light guide portion. Furthermore, since alignment of the support and light guide parts is not required, as is the case when the support and light guide parts are joined together with a bonding material, the productivity of the light guide plate can be increased. In addition, since there is no need to provide an adhesive such as resin between the support and light guide parts, a decrease in the heat resistance and durability of the light guide plate is less likely to occur.

[0010] In the method for manufacturing a light guide plate according to Embodiment 2, in the step of preparing the molding member according to Embodiment 1, a molding member may be prepared having a support base material composed of a first black glass base material and a second black glass base material, and a light guide portion forming portion composed of a transparent glass base material, wherein the transparent glass base material is sandwiched between the first black glass base material and the second black glass base material. In the method for manufacturing a light guide plate according to Embodiment 2, since the molding member is heat-stretched and molded with the transparent glass base material sandwiched between the first black glass base material and the second black glass base material, a light guide plate can be easily manufactured. Furthermore, according to this manufacturing method, a light guide plate in which the support portion and the light guide portion are integrated can be obtained, so there is no need to provide a bonding material such as an adhesive between the support portion and the light guide portion. Therefore, light loss is less likely to occur at the boundary between the support portion and the light guide portion, as is the case when a bonding material such as an adhesive is provided between the support portion and the light guide portion. Furthermore, since alignment of the support and light guide parts is not required, as is the case when the support and light guide parts are joined together with a bonding material, the productivity of the light guide plate can be increased. In addition, since there is no need to provide an adhesive such as resin between the support and light guide parts, a decrease in the heat resistance and durability of the light guide plate is less likely to occur.

[0011] In the method for manufacturing a light guide plate according to Embodiment 3, in Embodiment 2, it is preferable that the width of the transparent glass base material is narrower than the widths of the first black glass base material and the second black glass base material in a direction perpendicular to the stretching direction of the molding member. In this case, in the resulting light guide plate, the protruding portions of the first black glass plate and the second black glass plate make it difficult for the end face of the transparent glass sheet to come into contact with the outside, thus making it easier to avoid damage to the end face of the transparent glass sheet during the series of manufacturing processes.

[0012] In the method for manufacturing a light guide plate according to Embodiment 4, in the step of preparing the molding member according to Embodiment 1, a molding member may be prepared having a support base material made of a black glass base material having through holes, and a light guide portion forming portion made of the through holes in the black glass base material.

[0013] A light guide plate according to aspect 5 of the present invention is a light guide plate having a black support portion and a light guide portion, wherein the support portion is composed of a first black glass plate and a second black glass plate, and the light guide portion is composed of a transparent glass sheet, the transparent glass sheet is arranged between the first black glass plate and the second black glass plate, and the first black glass plate, the second black glass plate and the transparent glass sheet are integrated. In the light guide plate of aspect 5, since the first black glass plate and the second black glass plate constituting the support portion and the transparent glass sheet constituting the light guide portion are integrated, there is no need to provide a bonding material such as an adhesive between the support portion and the light guide portion, and as described above, the desired light can be efficiently extracted, and productivity can be increased.

[0014] In the light guide plate according to embodiment 6, it is preferable that the first black glass plate and the second black glass plate and the transparent glass sheet are fused together in embodiment 5.

[0015] In the light guide plate according to Embodiment 7, in Embodiment 5 or Embodiment 6, the light guide plate has opposing first and second end faces and opposing third and fourth end faces connecting the first and second end faces, wherein the first and second end faces are end faces arranged in the light guide direction, the end faces of the first black glass plate and the second black glass plate and the end face of the transparent glass sheet are aligned at the first and second end faces, and the end faces of the transparent glass sheet are preferably positioned further inside the light guide plate than the end faces of the first and second black glass plates at the third and fourth end faces. In this case, the protruding portions of the first and second black glass plates make it difficult for the end faces of the transparent glass sheet to come into contact with the outside, making it easier to avoid damage to the end faces of the transparent glass sheet. Furthermore, light leakage from the third and fourth end faces of the light guide plate can be further suppressed.

[0016] In the light guide plate according to Embodiment 8, in any one embodiment from Embodiments 5 to 7, the light guide plate has opposing first and second end faces and opposing third and fourth end faces connecting the first and second end faces, wherein the first and second end faces are end faces arranged in the light guide direction, and the third and fourth end faces are forged surfaces. If the third and fourth end faces are forged surfaces, it becomes easier to avoid damage to the third and fourth end faces.

[0017] In the light guide plate according to embodiment 9, in any one embodiment from embodiment 5 to embodiment 8, it is preferable that at least one of the glass members among the first black glass plate, the second black glass plate, and the transparent glass sheet has an elongation mark that extends in the light guide direction.

[0018] In the light guide plate according to Embodiment 10, in any one embodiment from Embodiments 5 to 9, it is preferable that the first black glass plate and the second black glass plate each have a greater thickness than the transparent glass sheet. In this case, unwanted light from the light incident on the transparent glass sheet can be absorbed more reliably by the first black glass plate and the second black glass plate, and higher quality light can be selectively emitted from the light emission surface of the light guide plate. Furthermore, incident light from sides other than the incident end face of the transparent glass sheet can be absorbed more reliably by the first black glass plate and the second black glass plate, and higher quality light can be selectively emitted from the light emission surface of the light guide plate.

[0019] In the light guide plate according to embodiment 11, in any one embodiment from embodiment 5 to embodiment 10, the absolute value of the difference in average thermal expansion coefficients between the black glass constituting the first black glass plate and the second black glass plate and the transparent glass constituting the transparent glass sheet in the temperature range of 30°C to 380°C is 30 × 10 -7It is preferably below / ℃. In this case, the residual stress applied to the transparent glass sheet due to the difference in the coefficient of thermal expansion of each member constituting the light guide plate can be reduced. As a result, it becomes easier to avoid breakage of the transparent glass sheet, etc., and higher-quality light can be selectively emitted from the light-emitting surface of the light guide plate.

[0020] In the light guide plate according to Aspect 12, in any one of Aspects 5 to 11, it is preferable that the black glass constituting the first black glass plate and the second black glass plate has a larger average coefficient of thermal expansion in the temperature range of 30℃ to 380℃ than the transparent glass constituting the transparent glass sheet. In this case, it becomes easier to avoid breakage of the transparent glass sheet, etc., and higher-quality light can be selectively emitted from the light-emitting surface of the light guide plate.

[0021] In the light guide plate according to Aspect 13, in any one of Aspects 5 to 12, it is preferable that the absolute value of the difference in softening point between the black glass constituting the first black glass plate and the second black glass plate and the transparent glass constituting the transparent glass sheet is 200℃ or less. In this case, the amount of softening deformation of each member constituting the light guide plate can be made as equal as possible. As a result, it becomes possible to obtain a more uniform shape of the light guide plate by heat stretching and forming during the manufacture of the light guide plate.

[0022] In the light guide plate according to Aspect 14, in any one of Aspects 5 to 13, it is preferable that the black glass constituting the first black glass plate and the second black glass plate has a lower softening point than the transparent glass constituting the transparent glass sheet. In this case, while avoiding deformation of the transparent glass sheet in the heat stretching and forming during the manufacture of the light guide plate, more reliable fusion between the transparent glass sheet and the black glass plate becomes possible.

[0023] A light guide plate according to embodiment 15 of the present invention is a light guide plate having a black support portion and a light guide portion, wherein the support portion is made of black glass having a through hole, and the light guide portion is made of the space within the through hole of the black glass. In the light guide plate of embodiment 15, there is no need to provide a bonding material such as an adhesive between the support portion and the light guide portion, and as described above, the desired light can be efficiently extracted and productivity can be increased. Furthermore, since the light guide portion is made of the space (air layer) within the through hole of the support portion, reflection of light on the light incident surface and light emission surface of the light guide plate can be suppressed, and light can be efficiently emitted from the light incident surface. In addition, since the light guide portion does not come into contact with the outside, there is no risk of the light guide portion being damaged.

[0024] In the light guide plate according to embodiment 16, in embodiment 15, it is preferable that the volume of the black glass is larger than the volume of the space within the through-hole. In this case, unwanted light from the light incident into the space can be absorbed more reliably by the black glass plate, and higher quality light can be selectively emitted from the light emission surface of the light guide plate. [Effects of the Invention]

[0025] According to the present invention, it is possible to provide a light guide plate and a method for manufacturing the light guide plate that can efficiently extract desired light and increase productivity. [Brief explanation of the drawing]

[0026] [Figure 1] Figure 1 is a schematic perspective view showing a light guide plate according to a first embodiment of the present invention. [Figure 2] Figure 2 is a schematic cross-sectional view of the portion along line AA in Figure 1. [Figure 3] Figure 3 is a schematic cross-sectional view of the portion along line BB in Figure 1. [Figure 4] Figure 4 is a schematic diagram illustrating an example of a method for manufacturing a light guide plate according to the first embodiment of the present invention. [Figure 5]Figures 5(a) and (b) are schematic cross-sectional views showing a light guide plate according to a second embodiment of the present invention. [Figure 6] Figures 6(a) and (b) are schematic cross-sectional views showing a light guide plate according to a third embodiment of the present invention. [Figure 7] Figure 7 is a schematic cross-sectional view showing an example of a microscope kit according to one embodiment of the present invention. [Modes for carrying out the invention]

[0027] The embodiments are described below. However, the following embodiments are merely illustrative, and the present invention is not limited to these embodiments. In addition, in each drawing, components having substantially the same function may be referred to by the same reference numerals.

[0028] [Light guide plate] (First Embodiment) Figure 1 is a schematic perspective view showing a light guide plate according to a first embodiment of the present invention. Figure 2 is a schematic cross-sectional view of the portion along line AA in Figure 1. Figure 3 is a schematic cross-sectional view of the portion along line BB in Figure 1. In each drawing, the length direction of the light guide plate is the X direction, the width direction is the Y direction, and the thickness direction is the Z direction. The X direction corresponds to the light guidance direction of the light guide plate and also corresponds to the stretching direction in the manufacturing method of the light guide plate described later.

[0029] As shown in Figures 1 to 3, the light guide plate 1 has a black support portion 2 and a light guide portion 3. In this embodiment, the support portion 2 is composed of a first black glass plate 4 and a second black glass plate 5. The light guide portion 3 is composed of a transparent glass sheet 6. The transparent glass sheet 6 is placed between the first black glass plate 4 and the second black glass plate 5.

[0030] The light guide plate 1 has a rectangular shape when viewed from above. However, the shape of the light guide plate 1 may also be circular or elliptical when viewed from above, and is not particularly limited.

[0031] The light guide plate 1 has a first main surface 1a and a second main surface 1b that are opposite each other. The light guide plate 1 also has first to fourth end surfaces 1c to 1f that connect the first main surface 1a and the second main surface 1b.

[0032] The respective areas of the first main surface 1a and the second main surface 1b of the light guide plate 1 are not particularly limited, but for example, 100 mm 2 Above 1500mm 2 The following is possible: The thickness of the light guide plate 1 is not particularly limited, but for example, it can be 0.2 mm or more and 4 mm or less.

[0033] In the X direction, which is the light-guiding direction of the light guide plate 1, the first end face 1c and the second end face 1d face opposite each other. In this embodiment, the first end face 1c of the light guide plate 1 has a light incident surface 1c1. The second end face 1d of the light guide plate 1 has a light emission surface 1d1. In the Y direction, which is perpendicular to the light-guiding direction of the light guide plate 1, the third end face 1e and the fourth end face 1f face opposite each other.

[0034] In the Z-direction, which is the thickness direction of the light guide plate 1, a transparent glass sheet 6 is positioned between the first black glass plate 4 and the second black glass plate 5. The first black glass plate 4 and the second black glass plate 5 and the transparent glass sheet 6 are integrated together. In this embodiment, the first black glass plate 4 and the second black glass plate 5 and the transparent glass sheet 6 are fused together and integrated.

[0035] In the light guide plate 1 of this embodiment, light emitted from the light source enters the light guide section 3 from the light incident surface 1c1. The light that enters the light guide section 3 travels along the X direction, which is the light guide direction, to the light emission surface 1d1. The light emitted from the light emission surface 1d1 is emitted in a sheet-like manner along the X direction.

[0036] In the light guide plate 1, the transparent glass sheet 6 constituting the light guide section 3 is sandwiched between the first black glass plate 4 and the second black glass plate 5 constituting the support section 2. Therefore, of the light incident into the transparent glass sheet 6, the light that travels toward the first black glass plate 4 and the second black glass plate 5 can be absorbed by the first black glass plate 4 and the second black glass plate 5. As a result, the emission of light other than parallel light that directly passes through the transparent glass sheet 6 can be suppressed, and the component of light other than parallel light in the light emitted from the light emission surface 1d1 of the light guide plate 1 can be reduced. Therefore, the light guide plate 1 can selectively emit high-quality light from the light emission surface 1d1.

[0037] Furthermore, in the light guide plate 1, the first black glass plate 4 and the second black glass plate 5 that constitute the support part 2 and the transparent glass sheet 6 that constitutes the light guide part 3 are integrated, so there is no need to provide a bonding material such as adhesive between the support part 2 and the light guide part 3. Therefore, light loss at the boundary between the support part 2 and the light guide part 3 is less likely to occur, as is the case when a bonding material such as adhesive is provided between the support part 2 and the light guide part 3. In addition, since there is no need to align the support part 2 and the light guide part 3, as is the case when the support part 2 and the light guide part 3 are joined with a bonding material, the productivity of the light guide plate 1 can be increased. Also, since there is no need to provide an adhesive such as resin between the support part 2 and the light guide part 3, a decrease in the heat resistance and durability of the light guide plate 1 is less likely to occur.

[0038] Thus, the light guide plate 1 of this embodiment can efficiently extract the desired light and also offers excellent productivity.

[0039] In this embodiment, as shown in Figure 2, the end faces of the first black glass plate 4 and the second black glass plate 5 are aligned with the end face of the transparent glass sheet 6 at the first end face 1c and the second end face 1d of the light guide plate 1. Furthermore, as shown in Figure 3, at the third end face 1e and the fourth end face 1f of the light guide plate 1, the end face of the transparent glass sheet 6 is positioned further inside the light guide plate 1 than the end faces of the first black glass plate 4 and the second black glass plate 5. In this case, the protruding portions of the first black glass plate 4 and the second black glass plate 5 make it difficult for the end face of the transparent glass sheet 6 to come into contact with the outside, thus making it easier to avoid damage to the end face of the transparent glass sheet 6. In addition, light leakage from the third end face 1e and the fourth end face 1f of the light guide plate 1 can be further suppressed. Moreover, the manufacturing method of the light guide plate 1 described later makes it easier to manufacture a light guide plate 1 with such a structure, thus further increasing the productivity of the light guide plate 1. However, in the present invention, the end faces of the first black glass plate 4 and the second black glass plate 5 do not need to be aligned with the end face of the transparent glass sheet 6 at the first end face 1c and the second end face 1d of the light guide plate 1, and are not particularly limited. Also, the end face of the transparent glass sheet 6 does not need to be positioned inside the light guide plate 1 at the third end face 1e and the fourth end face 1f of the light guide plate 1, and are not particularly limited.

[0040] Furthermore, as in this embodiment, it is preferable that the first end face 1c and the second end face 1d of the light guide plate 1 are end faces arranged in the X direction, which is the light guidance direction (the stretching direction in the manufacturing method of the light guide plate 1 described later). On the other hand, it is preferable that the third end face 1e and the fourth end face 1f of the light guide plate 1 are forged surfaces. Forged surfaces are smooth surfaces obtained without polishing by heat stretching molding such as redraw molding. If the third end face 1e and the fourth end face 1f are forged surfaces, it becomes easier to avoid damage to the third end face 1e and the fourth end face 1f. In addition, in the manufacturing method of the light guide plate 1 described later, it is easy to manufacture a light guide plate 1 in which the third end face 1e and the fourth end face 1f are forged surfaces, so the productivity of the light guide plate 1 can be further increased. Furthermore, the third end face 1e and the fourth end face 1f of the light guide plate 1 may be rounded.

[0041] In the present invention, it is preferable that at least one of the glass components, the first black glass plate 4, the second black glass plate 5, and the transparent glass sheet 6, has stretch marks in the X direction, which is the light-guiding direction. Stretch marks refer to traces of stretching caused by heat stretch molding, as described later in the manufacturing method of the light guide plate 1. Since such stretch marks tend to occur in a specific direction depending on the manufacturing method of the light guide plate 1 described later, if the light guide plate 1 has stretch marks, it is possible to easily identify the manufacturing method of the light guide plate 1 and the light-guiding direction.

[0042] Examples of stretch marks include streaks, veins, or bubbles that occur in the target member due to stretching. A streak refers to a streak that occurs in the stretching direction of the target member due to variations in thickness or undulation in a direction perpendicular to the stretching direction of the target member. Therefore, the direction in which the streaks extend is the same as the stretching direction of the target member, and in this embodiment, it is the X direction, which is the light-guiding direction. A veins refers to linear or band-shaped non-uniform areas that occur in parts of the target member where the refractive index differs from the rest. Veins are caused by variations in temperature and composition during the manufacturing process of the target member, and are particularly likely to occur due to temperature fluctuations when the target member is cooled. Bubbles are air bubbles that occur during the manufacturing process of the target member. Bubbles tend to occur as linear bubbles that extend linearly in the stretching direction.

[0043] It is preferable that the first black glass plate 4 and the second black glass plate 5 are each thicker than the transparent glass sheet 6. In this case, unwanted light from the light incident on the transparent glass sheet 6 can be absorbed more reliably by the first black glass plate 4 and the second black glass plate 5, and high-quality light can be more selectively emitted from the light emission surface 1d1 of the light guide plate 1. In addition, incident light from sides other than the incident end face of the transparent glass sheet 6 can be absorbed more reliably by the first black glass plate 4 and the second black glass plate 5, and high-quality light can be selectively emitted from the light emission surface 1d1 of the light guide plate 1. Furthermore, in this case, it is easier to avoid the transparent glass sheet 6 being damaged by external forces applied to it by the first black glass plate 4 and the second black glass plate 5.

[0044] The thickness of the first black glass plate 4 and the second black glass plate 5 is preferably 0.1 mm or more, more preferably 0.5 mm or more, preferably 2 mm or less, and more preferably 1 mm or less, respectively. When the thickness of the first black glass plate 4 and the second black glass plate 5 is greater than or equal to the lower limit, the light absorption capacity of the first black glass plate 4 and the second black glass plate 5 can be further increased. Also, when the thickness of the first black glass plate 4 and the second black glass plate 5 is less than or equal to the upper limit, the light guide plate 1 can be made thinner.

[0045] The thickness of the transparent glass sheet 6 is preferably 1 μm or more, more preferably 3 μm or more, even more preferably 10 μm or more, preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less. Furthermore, it is preferable that the thickness of the transparent glass sheet 6 be uniform. For example, when the thickness of the transparent glass sheet 6 is measured at any five locations, it is preferable that the difference in thickness of the transparent glass sheet 6 is within 3% of a 20 μm thickness. Such a transparent glass sheet 6 can be obtained, for example, by the redraw method.

[0046] The absolute value of the difference in the average coefficient of thermal expansion between the black glass constituting the first black glass plate 4 and the second black glass plate 5 and the transparent glass constituting the transparent glass sheet 6 in the temperature range of 30°C to 380°C is preferably 30×10 -7 / °C or less, more preferably 20×10 -7 / °C or less, still more preferably 10×10 -7 / °C or less. In this case, the residual stress applied to the transparent glass sheet 6 due to the difference in the coefficient of thermal expansion of each member constituting the light guide plate 1 can be reduced. As a result, it becomes easier to avoid breakage or the like of the transparent glass sheet 6, and higher-quality light can be selectively emitted from the light emitting surface 1d1 of the light guide plate 1. The lower limit value of the absolute value of the difference in the average coefficient of thermal expansion is not particularly limited, but in reality, for example, it can be 1×10 -7 / °C or more.

[0047] The black glass constituting the first black glass plate 4 and the second black glass plate 5 preferably has a larger average coefficient of thermal expansion than the transparent glass constituting the transparent glass sheet 6 in the temperature range of 30°C to 380°C.

[0048] The average coefficient of thermal expansion of the black glass constituting the first black glass plate 4 and the second black glass plate 5 in the temperature range of 30°C to 380°C can be, for example, 50×10 -7 / °C or more and 120×10 -7 / °C or less. Also, the average coefficient of thermal expansion of the transparent glass constituting the transparent glass sheet 6 in the temperature range of 30°C to 380°C can be, for example, 30×10 -7 / °C or more and 100×10 -7 / °C or less.

[0049] The absolute difference in the softening points between the black glass constituting the first black glass plate 4 and the second black glass plate 5 and the transparent glass constituting the transparent glass sheet 6 is preferably 200°C or less, more preferably 150°C or less, and even more preferably 100°C or less. In this case, the amount of softening deformation of each component constituting the light guide plate 1 can be made as equal as possible, and as a result, it becomes possible to obtain an even more uniform shape of the light guide plate 1 by heat stretch molding during the manufacturing of the light guide plate 1, as described later. The lower limit of the absolute value of the difference in softening points is not particularly limited, but in reality, it can be, for example, 10°C or more.

[0050] It is preferable that the black glass constituting the first black glass plate 4 and the second black glass plate 5 has a lower softening point than the transparent glass constituting the transparent glass sheet 6. In this case, deformation of the transparent glass sheet 6 during heat stretching molding when manufacturing the light guide plate 1 can be avoided, while more reliable fusion between the transparent glass sheet 6 and the black glass plates (first black glass plate 4 and second black glass plate 5) becomes possible.

[0051] The softening point of the black glass constituting the first black glass plate 4 and the second black glass plate 5 can be, for example, 650°C or higher and 1000°C or lower. Similarly, the softening point of the transparent glass constituting the transparent glass sheet 6 can be, for example, 650°C or higher and 1000°C or lower.

[0052] The first black glass plate 4 and the second black glass plate 5 each have a light absorption rate of 90% or more, more preferably 93% or more, even more preferably 95% or more, and particularly preferably 98% or more at a thickness of 3 mm in wavelengths of 400 nm to 650 nm. Furthermore, there is no particular upper limit to the light absorption rate of the first black glass plate 4 and the second black glass plate 5 at a thickness of 3 mm in wavelengths of 400 nm to 650 nm, but it can be, for example, 100%.

[0053] Furthermore, the first black glass plate 4 and the second black glass plate 5 each have a reflectance of 4% or less, more preferably 3% or less, even more preferably 2% or less, and particularly preferably 1% or less at a thickness of 3 mm in the wavelength range of 400 nm to 650 nm. The lower limit of the reflectance of the first black glass plate 4 and the second black glass plate 5 at a thickness of 3 mm in the wavelength range of 400 nm to 650 nm is not particularly limited, but can be, for example, 0.1%.

[0054] The first black glass plate 4 and the second black glass plate 5 can be made by appropriately selecting black glass, for example, having a light absorption rate equal to or greater than the above lower limit. Examples of materials for the first black glass plate 4 and the second black glass plate 5 include glass containing at least one selected from the group consisting of Fe2O3, CuO, NiO, and Co3O4. Examples of glass that can be used include soda-lime glass, alkali-free glass, aluminosilicate glass, borosilicate glass, and phosphate-based glass.

[0055] If the material of the first black glass plate 4 and the second black glass plate 5 is phosphoric acid-based glass, for example, a glass containing the following components by mass%, can be used: P2O5 50%~80%, SiO2 0%~10%, B2O 30%~10%, Al2O 30%~10%, Li2O+Na2O+K2O 0%~10%, MgO+CaO+SrO+BaO 0%~20%, and Fe2O3+CuO+NiO+Co3O 4 1%~30%. Here, "Li2O+Na2O+K2O" refers to the combined amounts of Li2O, Na2O, and K2O; "MgO+CaO+SrO+BaO" refers to the combined amounts of MgO, CaO, SrO, and BaO; and "Fe2O3+CuO+NiO+Co3O4" refers to the combined amounts of Fe2O3, CuO, NiO, and Co3O4.

[0056] The first black glass plate 4 and the second black glass plate 5 may be made of different materials, but from the viewpoint of further increasing the productivity of the light guide plate 1, it is preferable that the first black glass plate 4 and the second black glass plate 5 are made of the same material.

[0057] The transparent glass sheet 6 transmits at least a portion of the visible wavelength range. Specifically, the transparent glass sheet 6 has a light transmittance of 80% or more, more preferably 85% or more, even more preferably 90% or more, and particularly preferably 95% or more at a thickness of 3 mm at wavelengths of 400 nm to 650 nm. The upper limit of the light transmittance of the transparent glass sheet 6 at a thickness of 3 mm at wavelengths of 400 nm to 650 nm may be 100%.

[0058] The material of the transparent glass sheet 6 is not particularly limited and includes, for example, quartz glass, soda-lime glass, alkali-free glass, aluminosilicate glass, borosilicate glass, etc.

[0059] The following describes an example of a manufacturing method for the light guide plate 1.

[0060] In the manufacturing method of the light guide plate 1 of this embodiment, first, a molding member is prepared having a support base material made of black glass and a light guide portion forming portion.

[0061] More specifically, when preparing a molding component, a molding component is prepared that has a support base material composed of a first black glass base material and a second black glass base material, and a light guide forming part composed of a transparent glass base material, with the transparent glass base material sandwiched between the first black glass base material and the second black glass base material.

[0062] In this embodiment, the first black glass base material and the second black glass base material are plate-shaped. The first black glass base material and the second black glass base material are glass base materials for forming the first black glass plate 4 and the second black glass plate 5 by heat stretching molding as described later. Therefore, the thickness of the first black glass base material and the second black glass base material is greater than that of the first black glass plate 4 and the second black glass plate 5. The thickness of the first black glass base material and the second black glass base material can be, for example, 1 mm or more and 300 mm or less.

[0063] In this embodiment, the transparent glass base material is plate-shaped. The transparent glass base material is used to form the transparent glass sheet 6 by heat stretching molding, as described later. Therefore, the thickness of the transparent glass base material is greater than that of the transparent glass sheet 6. The thickness of the transparent glass base material can be, for example, 0.03 mm or more and 6 mm or less.

[0064] Next, the prepared molding member is heated and stretched to obtain a light guide plate base material. The obtained light guide plate base material is then cut to the desired size. This allows the light guide plate 1 to be obtained. The method for heating and stretching the molding member can be explained, for example, using Figure 4.

[0065] As shown in Figure 4, first, a molding member 11 having a support base material 12 and a light guide forming portion 13 is prepared, and the molding member 11 is positioned so that the light guide forming portion 13 extends in the X direction, which is the stretching direction. Next, the molding member 11 is softened by heating it with a heater 17, and the softened molding member 11 is stretched by pulling it downward with a pair of stretching rollers 18. This obtains a light guide plate base material 11A. Next, the light guide plate base material 11A is cut to the desired size with a cutting machine 19 to obtain the light guide plate 1 shown in Figures 1 to 3.

[0066] The method for heat-stretching the molding member 11 is not particularly limited, but it is preferable to use the redraw molding method described above. The temperature for heat-stretching is not particularly limited, but it is preferably 600°C or higher, more preferably 700°C or higher, preferably 1000°C or lower, and more preferably 900°C or lower.

[0067] In a direction perpendicular to the stretching direction of the molding member 11, it is desirable that the width of the transparent glass base material be narrower than the widths of the first black glass base material and the second black glass base material, respectively. In this case, in the resulting light guide plate 1, the protruding portions of the first black glass plate 4 and the second black glass plate 5 make it difficult for the end face of the transparent glass sheet 6 to come into contact with the outside, thus making it easier to avoid damage to the end face of the transparent glass sheet 6.

[0068] Thus, in the manufacturing method of this embodiment, a light guide plate 1 can be obtained by heat-stretching a molding member 11 in which a transparent glass base material is sandwiched between a first black glass base material and a second black glass base material. Since there is no need to align the support part 2 and the light guide part 3, as in the case where the support part and the light guide part are joined with a bonding material, the productivity of the light guide plate 1 can be increased.

[0069] Furthermore, in the manufacturing method of this embodiment, a molding member 11 in which a transparent glass base material is sandwiched between a first black glass base material and a second black glass base material is heat-stretch-molded. As a result, in the resulting light guide plate 1, the first black glass plate 4 and the second black glass plate 5 and the transparent glass sheet 6 are fused together and integrated. Therefore, the resulting light guide plate 1 can efficiently extract the desired light.

[0070] (Second embodiment) Figures 5(a) and 5(b) are schematic cross-sectional views showing a light guide plate according to a second embodiment of the present invention. Figure 5(a) is a cross-sectional view corresponding to Figure 2 of the first embodiment, and is a cross-sectional view along the X direction, which is the light guide direction, and the Z direction, which is the thickness direction. Figure 5(b) is a cross-sectional view corresponding to Figure 3 of the first embodiment, and is a cross-sectional view along the Y direction (width direction), which is perpendicular to the light guide direction, and the Z direction, which is the thickness direction.

[0071] As shown in Figure 5(b), in the light guide plate 21, the support portion 22 is made of a black glass plate 24 having a frame-like shape in cross-section along the Y and Z directions. A transparent glass sheet 26, which will become the light guide portion 23, is arranged inside this frame-shaped black glass plate 24 that constitutes the support portion 22. Therefore, as shown in Figures 5(a) and (b), the transparent glass sheet 26 is covered by the black glass plate 24 on all surfaces of the light guide plate 21 except for the first end face 21c and the second end face 21d. The glass used to make up the black glass plate 24 is the same glass described as the glass used to make up the first black glass plate 4 and the second black glass plate 5 in the first embodiment. The glass used to make up the transparent glass sheet 26 is the same glass described as the glass used to make up the transparent glass sheet 6 in the first embodiment.

[0072] In the manufacturing method of the light guide plate 21, a molding member is prepared which has a support base material made of a black glass base material having through holes and a light guide portion forming portion made of a transparent glass base material, with the transparent glass base material placed in the through holes of the black glass base material. The cross-sectional shape of the through holes in the black glass base material is rectangular. The glass that constitutes the black glass base material is the same glass described as the glass that constitutes the first black glass plate 4 and the second black glass plate 5 in the first embodiment. The glass that constitutes the transparent glass base material is the same glass described as the glass that constitutes the transparent glass sheet 6 in the first embodiment.

[0073] Next, the molding member is heated and stretch-molded to obtain a light guide plate base material. The obtained light guide plate base material is then cut to the desired size. This allows the light guide plate 21 to be obtained. In the manufacturing method of the light guide plate 21, for example, as shown in Figure 4, the prepared molding member 11 is arranged so that the light guide portion forming portion 13 extends in the X direction, which is the stretching direction, and then heated and stretch-molded to produce the light guide plate 21 shown in Figures 5(a) and (b).

[0074] Other aspects are the same as in the first embodiment.

[0075] In the light guide plate 21 of the second embodiment, the black glass plate 24 constituting the support portion 22 and the transparent glass sheet 26 constituting the light guide portion 23 are integrated, so the desired light can be extracted efficiently, and moreover, since there is no need to align the support portion 22 and the light guide portion 23 as in the case where the support portion and the light guide portion are joined by a bonding material, productivity can be increased.

[0076] As in the second embodiment, the transparent glass sheet 26 may be covered by the black glass plate 24 at the third end face 21e and the fourth end face 21f of the light guide plate 21. In this case, light leakage from the third end face 21e and the fourth end face 21f of the light guide plate 21 can be suppressed even more reliably.

[0077] (Third embodiment) Figures 6(a) and 6(b) are schematic cross-sectional views showing a light guide plate according to a third embodiment of the present invention. Figure 6(a) is a cross-sectional view corresponding to Figure 2 of the first embodiment, and is a cross-sectional view along the X direction, which is the light guide direction, and the Z direction, which is the thickness direction. Figure 6(b) is a cross-sectional view corresponding to Figure 3 of the first embodiment, and is a cross-sectional view along the Y direction (width direction), which is perpendicular to the light guide direction, and the Z direction, which is the thickness direction.

[0078] As shown in Figure 6(b), in the light guide plate 31, the support portion 32 is made of black glass 34 having a through hole 35. The light guide portion 33 is made of the space 36 (air layer) within the through hole 35 of the support portion 32. The shape of the through hole 35 of the support portion 32 is rectangular. The glass used to make up the black glass 34 is the same glass described as the glass used to make up the first black glass plate 4 and the second black glass plate 5 in the first embodiment.

[0079] As shown in Figure 6(a), in the light guide plate 31 of this embodiment, light emitted from the light source enters the light guide section 33 (space 36) from the light incident surface 31c1. The light that enters the light guide section 33 travels along the X direction, which is the light guide direction, to the light emission surface 31d1. The light emitted from the light emission surface 31d1 is emitted in a sheet-like manner along the X direction.

[0080] Preferably, the volume of the black glass 34 constituting the support portion 32 is larger than the volume of the space 36 constituting the light guide portion 33. In this case, unwanted light from the light incident into the space 36 can be absorbed more reliably by the black glass 34, and higher quality light can be selectively emitted from the light emission surface 31d1 of the light guide plate 31.

[0081] In the manufacturing method of the light guide plate 31, a molding member is prepared, which has a support base material made of a black glass base material having through holes, and a light guide portion forming portion made of a space within the through holes of the black glass base material. The shape of the through holes in the black glass base material is rectangular. The glass used to make up the black glass base material is the same glass described as the glass used to make up the first black glass plate 4 and the second black glass plate 5 in the first embodiment.

[0082] Next, the molding member is heated and stretch-molded to obtain a light guide plate base material. The obtained light guide plate base material is then cut to the desired size. This allows the light guide plate 31 to be obtained. In the manufacturing method of the light guide plate 31, for example, as shown in Figure 4, the prepared molding member 11 is arranged so that the light guide portion forming portion 13 extends in the X direction, which is the stretching direction, and then heated and stretch-molded to produce the light guide plate 31 shown in Figures 6(a) and (b).

[0083] Other aspects are the same as in the first embodiment.

[0084] In the light guide plate 31 of the third embodiment, the light that travels toward the black glass 34 from the light incident into the space 36, which is the light guide portion 33, can be absorbed by the black glass 34. Therefore, the component of light emitted from the light emission surface 31d1 of the light guide plate 31 that is not parallel light directly transmitted through the space 36 can be reduced. As a result, the light guide plate 31 can selectively emit high-quality light from the light emission surface 31d1.

[0085] Furthermore, since the light guide plate 31 can be manufactured simply by heat-stretching a black glass base material having through holes, there is no need to provide adhesives or other bonding materials. Therefore, unlike when adhesives or other bonding materials are provided between the support portion 32 and the light guide portion 33, light loss at the boundary between the support portion 32 and the light guide portion 33 is less likely to occur. In addition, since there is no need to align the support portion 32 and the light guide portion 33, the productivity of the light guide plate 31 can be increased. Moreover, since there is no need to use adhesives such as resins, the heat resistance and durability of the light guide plate 31 are less likely to decrease.

[0086] Thus, the light guide plate 31 of the third embodiment can efficiently extract the desired light, and moreover, it is highly productive because it does not require alignment of the support portion 32 and the light guide portion 33, as is the case when the support portion and the light guide portion are joined by a bonding material.

[0087] As in the third embodiment, the light guide portion 33 may be composed of a space 36 (air layer) within the through hole 35 of the support portion 32. In this case, since the reflection of light at the light incident surface 31c1 and the light emission surface 31d1 of the light guide plate 31 can be suppressed, light can be efficiently emitted from the light emission surface 31d1. Alternatively, the space 36 within the through hole 35 of the support portion 32 may be filled with resin or the like.

[0088] [Microscope Kit] Figure 7 is a schematic cross-sectional view showing an example of a microscope kit according to one embodiment of the present invention.

[0089] Microscope kit 41 is a microscope kit used in a light sheet microscope. Microscope kit 41 comprises a light guide plate 1 and a cell 47. The light guide plate 1 is the light guide plate described in the first embodiment. A light source 40 is provided on the light incident side of the light guide plate 1. For example, an LED (light-emitting diode) or an LD (laser diode) can be used as the light source 40. In this embodiment, a lens 46 is provided on the light incident surface 1c1 of the light guide plate 1.

[0090] A cell 47 for housing the object to be observed 48 is provided on the light-emitting side of the light guide plate 1. Preferably, one sample is housed in one cell 47, but multiple samples may be housed in each cell 47. The object to be observed 48 may be placed in a special solution within the cell 47 for observation. For example, a cell clearing solution can be used as the special solution.

[0091] Cell 47 is made of a transparent material. Examples of transparent materials include glass and resin. The dimensions of cell 47 can be, for example, a length of 3 mm or more and 5 mm or less, a width of 10 mm or more and 15 mm or less, and a height of 2 mm or more and 4 mm or less.

[0092] Preferably, the distance between the light guide plate 1 and the cell 47 is adjustable depending on the light intensity of the light guide plate 1 and the size of the object 48 to be observed inside the cell 47. This makes it possible to freely move the position of the cell 47 in relation to the light guide plate 1, either up and down or left and right.

[0093] The cell 47 may be in close contact with the light guide plate 1 via a refractive index matching agent. The refractive index matching agent can be provided, for example, between the second end face 1d of the light guide plate 1 and the side wall portion of the cell 47.

[0094] The refractive index matching agent is preferably made of a material with a viscosity such that it contacts the light guide plate 1 while the cell 47 is able to move up and down. For example, refractive index control resins such as acrylic resin or epoxy resin can be used as such a refractive index matching agent. Alternatively, the light guide plate 1 may be in close contact with the cell 47 while being able to move freely up and down or left and right.

[0095] Furthermore, an anti-reflective coating may be provided on the second end face 1d of the light guide plate 1. By providing an anti-reflective coating, the light incident from the light guide plate 1 can be more effectively captured into the cell 47. As the anti-reflective coating, for example, a dielectric multilayer film can be used. As the dielectric multilayer film, a multilayer film can be used that includes a high refractive index film with a relatively high refractive index and a low refractive index film with a relatively low refractive index. It is preferable that the high refractive index film and the low refractive index film are stacked alternately.

[0096] Examples of materials that can be used for high refractive index films include niobium oxide, titanium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silicon nitride, aluminum oxide, or aluminum nitride. Examples of materials that can be used for low refractive index films include silicon oxide, aluminum oxide, zirconium oxide, magnesium fluoride, or silicon nitride. While some examples are common to both high and low refractive index films, the materials should be appropriately selected so that the refractive index of the low refractive index film is relatively lower than that of the high refractive index film. High and low refractive index films can be formed, for example, by vapor deposition or sputtering.

[0097] The number of layers of the low refractive index film can be, for example, one to five layers. The number of layers of the high refractive index film can be, for example, one to five layers. In addition, the total number of layers of the dielectric multilayer film can be, for example, two to ten layers.

[0098] The thickness of each low-refractive-index film layer can be, for example, between 5 nm and 1000 nm. The thickness of each high-refractive-index film layer can be, for example, between 5 nm and 1000 nm. The overall thickness of the dielectric multilayer film can be, for example, between 2 nm and 10000 nm.

[0099] The thickness of the anti-reflective coating is preferably 5 nm or more, more preferably 50 nm or more, preferably 500 nm or less, and more preferably 100 nm or less. In this case, the light incident from the light guide plate 1 can be more effectively captured into the cell 47.

[0100] A film that adjusts light reflection may be provided on the inner surface of cell 47. Examples of films that adjust light reflection include the anti-reflective film, light-absorbing film, or reflective film mentioned above. By providing a film that adjusts light reflection, the component due to reflected light on the inner surface of cell 47 can be adjusted, and the resolution can be further improved when used in an optical sheet microscope.

[0101] In the microscope kit 41 of this embodiment, light emitted from the light source 40 enters the transparent glass sheet 6 through the lens 46 from the first end face 1c of the light guide plate 1. Within the transparent glass sheet 6, the light travels along the X direction, which is the light guiding direction. In addition, light emitted from the second end face 1d of the light guide plate 1 is emitted in a sheet-like manner along the X direction and enters the cell 47.

[0102] The microscope kit 41 of this embodiment includes a light guide plate 1, which reduces the amount of light emitted from the second end face 1d that is not parallel light directly transmitted through the transparent glass sheet 6. As a result, high-quality light can be selectively incident into the cell 47 from the second end face 1d, improving the resolution of the light sheet microscope. [Explanation of symbols]

[0103] 1, 21, 31...Light guide plate 1a, 21a, 31a... First principal surface 1b, 21b, 31b... Second principal plane 1c, 21c, 31c... First end face 1c1, 21c1, 31c1...Light incidence surface 1d, 21d, 31d... Second end faces 1d1, 21d1, 31d1... Light-emitting surface 1e, 21e, 31e... Third end face 1f, 21f, 31f...the fourth end face 2, 22, 32...Support part 3, 23, 33... Light guide section 4…First black glass plate 5…Second black glass plate 6.26...Transparent glass sheet 11…Molding components 11A…Light guide plate base material 12...Support base material 13...Light guiding part forming part 17… Heater 18... Stretching roller 19...cutting machine 24...Black glass plate 34…Black glass 35…Through hole 36…Space 40...Light source 41…Microscope kit 46... Lens 47...Cell 48...Object of observation

Claims

1. A method for manufacturing a light guide plate having a black support part and a light guide part, A step of preparing a molding member having a support base material made of black glass and a light guide forming part, The process involves heating and stretching the molding member to obtain a light guide plate base material, The process of cutting the light guide plate base material to obtain a light guide plate, A method for manufacturing a light guide plate, comprising the features described above.

2. In the process of preparing the molding member, A support base material composed of a first black glass base material and a second black glass base material, A light guide forming section is made of a transparent glass base material, It has, A method for manufacturing a light guide plate according to claim 1, wherein a molding member is prepared in which the transparent glass base material is sandwiched between the first black glass base material and the second black glass base material.

3. The method for manufacturing a light guide plate according to claim 2, wherein, in a direction perpendicular to the stretching direction of the molding member, the width of the transparent glass base material is narrower than the widths of the first black glass base material and the second black glass base material, respectively.

4. In the process of preparing the molding member, A support base material is made of a black glass base material having through holes, The light guide portion is formed by the through-holes in the black glass base material, A method for manufacturing a light guide plate according to claim 1, comprising preparing a molding member having the above.

5. A light guide plate having a black support portion and a light guide portion, The support portion is composed of a first black glass plate and a second black glass plate. The light guide portion is made of a transparent glass sheet. A light guide plate in which the transparent glass sheet is placed between the first black glass plate and the second black glass plate, and the first black glass plate, the second black glass plate and the transparent glass sheet are integrated together.

6. The light guide plate according to claim 5, wherein the first black glass plate and the second black glass plate and the transparent glass sheet are fused together.

7. The light guide plate has a first end face and a second end face that are opposite to each other, and a third end face and a fourth end face that connect the first end face and the second end face and are opposite to each other. The first end face and the second end face are end faces arranged in the light guide direction, At the first and second end faces, the end faces of the first black glass plate and the second black glass plate are aligned with the end face of the transparent glass sheet. The light guide plate according to claim 5 or 6, wherein at the third and fourth end faces, the end faces of the transparent glass sheet are positioned further inside the light guide plate than the end faces of the first black glass plate and the second black glass plate.

8. The light guide plate has a first end face and a second end face that are opposite to each other, and a third end face and a fourth end face that connect the first end face and the second end face and are opposite to each other. The first end face and the second end face are end faces arranged in the light guide direction, The light guide plate according to claim 5 or 6, wherein the third end face and the fourth end face are forged surfaces.

9. The light guide plate according to claim 5 or 6, wherein at least one of the glass members among the first black glass plate, the second black glass plate, and the transparent glass sheet has an elongation mark extending in the light guide direction.

10. The light guide plate according to claim 5 or 6, wherein the first black glass plate and the second black glass plate are each thicker than the transparent glass sheet.

11. The absolute value of the difference in average thermal expansion coefficients between the black glass constituting the first black glass plate and the second black glass plate and the transparent glass constituting the transparent glass sheet in the temperature range of 30°C to 380°C is 30 × 10 －７ The light guide plate according to claim 5 or 6, wherein the temperature is below / ℃.

12. The light guide plate according to claim 5 or 6, wherein the black glass constituting the first black glass plate and the second black glass plate has a larger average coefficient of thermal expansion in the temperature range of 30°C to 380°C than the transparent glass constituting the transparent glass sheet.

13. The light guide plate according to claim 5 or 6, wherein the absolute value of the difference in softening points between the black glass constituting the first black glass plate and the second black glass plate and the transparent glass constituting the transparent glass sheet is 200°C or less.

14. The light guide plate according to claim 5 or 6, wherein the black glass constituting the first black glass plate and the second black glass plate has a lower softening point than the transparent glass constituting the transparent glass sheet.

15. A light guide plate having a black support portion and a light guide portion, The support portion is made of black glass having a through hole. A light guide plate in which the light guide portion is formed by the space within the through-hole of the black glass.

16. The light guide plate according to claim 15, wherein the volume of the black glass is greater than the volume of the space within the through hole.

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