1. An illumination device comprising:
a light guide plate;
an intermediate light guide disposed along one side face of the light guide plate; and
a light emitting element disposed at an end face in a lengthwise direction of the intermediate light guide,
wherein the side face of the light guide plate serves as a light incident face from which light is introduced, light emitted from the light emitting element is introduced into the light guide plate through the intermediate light guide and the light incident face, and the light propagating inside the light guide plate is emitted from one surface of the light guide plate,
wherein the intermediate light guide protrudes from the light guide plate in a direction along the light incident face of the light guide plate toward the light emitting element, a side face of the intermediate light guide opposing the side face of the light guide plate serves as an emergent face from which the light from the light emitting element emerges toward the light guide plate, and an outer side face of the intermediate light guide remote from the emergent face serves as a reflecting face for reflecting the light propagating inside the intermediate light guide,
wherein the outer side face of the intermediate light guide is provided with at least one of a plurality of grooves of wedge-shaped cross section or a plurality of minute irregularities provided distant from the end face of the intermediate light guide, and a reflective film formed on the at least one of grooves or irregularities, and
wherein the at least one of grooves or irregularities on the outer side face of the intermediate light guide extend from a position at a distance within the range of \u22121 mm to +0.5 mm from an extension line of an end face of the light guide plate close to the light emitting element, the extension line reaching the outer side face of the intermediate light guide, when the symbol \u201c\u2212\u201d indicates a side offset from the extension line toward the light emitting element, and the symbol \u201c+\u201d indicates a side offset from the extension line away from the light emitting element.
2. An illumination device according to claim 1, wherein the outer side face of the intermediate light guide is provided with a prism face having the plurality of grooves.
3. An illumination device according to claim 2, wherein the prism face on the outer side face of the intermediate light guide extends from a position at a distance within the range of 0.5 mm to +0.5 mm from the extension line.
4. An illumination device according to claim 2, wherein the prism face on the outer side face of the intermediate light guide extends from the extension line.
5. An illumination device according to claim 2, wherein a pitch of the grooves one of exponentially and quadratically decreases away from the light emitting element.
6. An illumination device according to claim 2, wherein a depth of the grooves one of exponentially and cubicly increases away from the light emitting element.
7. An illumination device according to claim 2, wherein each of the grooves has a pair of inclined faces for reflecting light, and an angle defined by the inclined faces is within the range of 105\xb0 to 115\xb0.
8. An illumination device according to claim 1, wherein the outer side face of the intermediate light guide is provided with an uneven face having the plurality of minute irregularities.
9. An illumination device according to claim 5, wherein the uneven face on the outer side face of the intermediate light guide extends from a position at a distance within the range of 0.5 mm to +0.5 mm from the extension line.
10. An illumination device according to claim 5, wherein the uneven face on the outer side face of the intermediate light guide extends from the extension line.
11. An illumination device according to claim 1, wherein another surface of the light guide plate is provided with a plurality of prism grooves arranged in stripes in plan view and having gently inclined faces and sharply inclined faces inclined more sharply than the gently inclined faces.
12. An illumination device according to claim 11, wherein the extending direction of the prism grooves in the light guide plate intersects the light incident face.
13. A liquid crystal display device comprising:
an illumination device; and
a liquid crystal display unit to be illuminated by the illumination device,
wherein the illumination device comprises:
a light guide plate;
an intermediate light guide disposed along one side face of the light guide plate; and
a light emitting element disposed at an end face in a lengthwise direction of the intermediate light guide,
wherein the side face of the light guide plate serves as a light incident face from which light is introduced, light emitted from the light emitting element is introduced into the light guide plate through the intermediate light guide and the light incident face, and the light propagating inside the light guide plate is emitted from one surface of the light guide plate,
wherein the intermediate light guide protrudes from the light guide plate in a direction along the light incident face of the light guide plate toward the light emitting element, a side face of the intermediate light guide opposing the side face of the light guide plate serves as an emergent face from which the light from the light emitting element emerges toward the light guide plate, and an outer side face of the intermediate light guide remote from the emergent face serves as a reflecting face for reflecting the light propagating inside the intermediate light guide,
wherein the outer side face of the intermediate light guide is provided with at least one of a plurality of grooves of wedge-shaped cross section or a plurality of minute irregularities provided distant from the end face of the intermediate light guide, and a reflective film formed on the at least one of grooves or irregularities, and
wherein the at least one of grooves or irregularities on the outer side face of the intermediate light guide extend from a position at a distance within the range of \u22121 mm to +0.5 mm from an extension line of an end face of the light guide plate close to the light emitting element, the extension line reaching the outer side face of the intermediate light guide, when the symbol \u201c\u2212\u201d indicates a side offset from the extension line toward the light emitting element, and the symbol \u201c+\u201d indicates a side offset from the extension line away from the light emitting element.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A bending waveguide comprising:
a core having an input end and an output end, wherein at least the output end has a near field enhanced aperture structure; and
a metal cladding disposed around the core,
wherein the core is bent in a curve and a radius of curvature of the curve is a resonance radius at which an intensity of transmitted light with respect to a wavelength of incident light is a maximum.
2. The bending waveguide of claim 1, wherein an output end of the core has a C-shaped aperture structure, wherein a part of the metal cladding protrudes towards a center portion of the C-shaped aperture structure forming a ridge portion.
3. The bending waveguide of claim 2, wherein the core has a C-shaped cross-section throughout a length thereof.
4. The bending waveguide of claim 3, wherein the width of the ridge portion gradually decreases from the input end to the output end.
5. The bending waveguide of claim 1, wherein a cross-sectional area of the core is the same throughout a length of the core.
6. The bending waveguide of claim 1, wherein a cross-sectional area of an input end of the core is different from a cross-sectional area of the output end thereof.
7. The bending waveguide of claim 6, wherein a cross-sectional area of the core gradually decreases from the input end to the output end.
8. The bending waveguide of claim 7, wherein a thickness of the cross-section of the core is constant and a width of the cross-section of the core gradually decreases from the input end to the output end.
9. The bending waveguide of claim 1, wherein the core is bent in a circular curve having an angle \u03b8 (0<\u03b8<180) between the input end and the output end.
10. The bending waveguide of claim 1, wherein the core is bent in a curve, wherein the curve is defined by more than one radius of curvature.
11. A method of fabricating a bending waveguide, the method comprising:
forming a lower cladding layer by depositing metal on a substrate;
depositing a core layer patterned as a curve having a predetermined radius of curvature on the lower cladding layer, wherein a width and a thickness of an output end of the core layer is equal to or less than a wavelength of incident light and wherein a radius of curvature of the core layer is determined such that an intensity of transmitted light with respect to a wavelength of the incident light is a maximum; and
forming an upper cladding layer by depositing metal on the core layer.
12. The method of claim 11, wherein the depositing of the lower cladding layer comprises depositing metal on the substrate and forming a ridge portion by etching a part of the deposited metal.
13. The method of claim 11, wherein the depositing of the lower cladding layer comprises:
depositing resin on the lower cladding layer;
transferring a pattern to the resin;
curing an open area of the pattern by emitting ultraviolet rays onto the resin; and
removing the resin from an area which is not cured.
14. A light delivery module comprising:
a first waveguide which comprises:
a core having an input end and an output end, wherein the output end has a near field enhanced aperture structure; and
a metal cladding enclosing the core,
wherein the first waveguide is a bending waveguide in which the core is bent in a curve and a radius of curvature of the curve is a resonance radius at which an intensity of transmitted light with respect to a wavelength of incident light is a maximum.
15. The light delivery module of claim 14, further comprising a second waveguide which transmits light to the first waveguide.
16. The light delivery module of claim 15, wherein the first waveguide and the second waveguide are butt-coupled.
17. The light delivery module of claim 14, wherein an output end of the core of the first waveguide has a C-shaped aperture structure, wherein a part of the metal cladding protrudes towards a center portion of the C-shaped aperture structure forming a ridge portion.
18. The light delivery module of claim 17, wherein the core of the first waveguide has a C-shaped cross-section throughout a length thereof.
19. The light delivery module of claim 18, wherein the width of the ridge portion gradually decreases from the input end to the output end.
20. The light delivery module of claim 15, wherein a cross-sectional area of the core of the first waveguide gradually decreases from the input end to the output end.
21. The light delivery module of claim 14, wherein the core of the first waveguide is bent in a circular curve having an angle \u03b8 (0<\u03b8<180) between the input end and the output end.
22. The light delivery module of claim 14, wherein the core of the first waveguide is bent in a curve, wherein more than one radii of curvature define the curve.
23. A heat assisted magnetic recording head comprising: a magnetic recording portion which forms a magnetic field;
and a light delivery module which emits light, which heats a recording scheduled area of a magnetic recording medium,
wherein the light delivery module comprises:
a first waveguide which comprises a core having an input end and an output end, wherein the output end has a near field enhanced aperture structure, and a metal cladding enclosing the core; and
a second waveguide which transmits light to the first waveguide,
wherein the first waveguide is a bending waveguide in which the core is bent in a curve and a radius of curvature of the curve is a resonance radius at which an intensity of transmitted light with respect to a wavelength of incident light is a maximum.
24. The heat assisted magnetic recording head of claim 23, wherein, an input end of the second waveguide is provided at a side surface of the heat assisted magnetic recording head.
25. The heat assisted magnetic recording head of claim 24, wherein the first waveguide has an input end that is coupled to an output end of the second waveguide and also has an output end that faces a bottom surface of the heat assisted magnetic recording head.
26. The heat assisted magnetic recording head of claim 23, wherein an output end of the core of the first waveguide has a C-shaped aperture structure, wherein a part of the metal cladding protrudes towards a center portion of the C-shaped aperture structure forming a ridge portion.
27. The heat assisted magnetic recording head of claim 26, wherein the core of the first waveguide has a C-shaped aperture structure throughout a length thereof.
28. The heat assisted magnetic recording head of claim 27, wherein the width of the ridge portion gradually decreases from the input end to the output end.
29. The heat assisted magnetic recording head of claim 23, wherein a cross-sectional area of the core gradually decreases from the input end to the output end.
30. The bending waveguide of claim 10, wherein each said radii of curvature corresponds to a resonance radius.
31. The bending waveguide of claim 22, wherein each said radii of curvature corresponds to a resonance radius.