U.S. patent application number 12/285829 was filed with the patent office on 2009-02-26 for indicator lamp having a converging lens.
Invention is credited to Toshio Shimada.
Application Number | 20090052190 12/285829 |
Document ID | / |
Family ID | 34681966 |
Filed Date | 2009-02-26 |
United States Patent
Application |
20090052190 |
Kind Code |
A1 |
Shimada; Toshio |
February 26, 2009 |
Indicator lamp having a converging lens
Abstract
It is sought to provide an indicator lamp, which is excellent
not only in short distance visual recognition property but also in
long distance one, as well as being further excellent in sight
field angle property. An indicator lamp includes a light-emitting
element 1 and a light-emitting element lens 2 having a
light-emitting element mounting cavity 3 formed at the bottom, in
which the light-emitting element disposed in the cavity 3 emits
light to be fully reflected by the peripheral surface of the lens 1
and proceeds as emission light flux forwardly of the lens 1. The
slope angle of the peripheral surface with respect to the lens axis
is reduced progressively from the bottom toward the lens front
surface 5 in three stages, thus forming circumferential corners 7
and 8 as boundaries between adjacent ones of the three stages. The
circumferential corners scatter light emitted from the light
emitting element 2 to provide concentric emission light fluxes as
viewed from the side of the lens front.
Inventors: |
Shimada; Toshio; (Nagano,
JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W., SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
34681966 |
Appl. No.: |
12/285829 |
Filed: |
October 15, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10595094 |
Feb 9, 2006 |
7473013 |
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PCT/JP2004/018518 |
Dec 6, 2004 |
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12285829 |
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Current U.S.
Class: |
362/296.05 |
Current CPC
Class: |
F21V 5/04 20130101; H01L
33/60 20130101; H01L 33/58 20130101; F21W 2111/00 20130101; Y10S
362/80 20130101; F21V 7/0091 20130101; F21K 9/69 20160801 |
Class at
Publication: |
362/296.05 |
International
Class: |
F21V 7/04 20060101
F21V007/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 12, 2003 |
JP |
2003-411913 |
Feb 13, 2004 |
JP |
2004-36824 |
Mar 22, 2004 |
JP |
2004-82559 |
Claims
1. An indicator lamp comprising: a light-emitting element; a lens
body having a cavity extending from a rear of said lens body, said
cavity having a substantially cylindrical front portion, said
cavity including a rear portion having a diameter greater than that
of said front portion and being defined by a stepped extension
surface, said stepped extension surface being tapered radially
outwardly and toward a front of said lens body, a front surface of
said cavity being convex and projecting toward a front surface of
said lens body, said light-emitting element being arranged with
said cavity; and a full reflection lens disposed atop said
light-emitting element within said cavity, said light-emitting
element emitting light to be reflected by said full reflection lens
and proceed forwardly of said full reflection lens, said full
reflection lens including a convex lens portion being disposed atop
said light-emitting element, said convex lens portion being formed
by filling a transparent polymer material into a frame disposed so
as to surround said light-emitting element from above said frame so
as to be raised in a convex shape.
2. The indicator lamp according to claim 1, wherein said frame is
made of a transparent material.
Description
[0001] This is a divisional of U.S. application Ser. No.
10/595,094, filed Feb. 9, 2006, which is the National Stage of
International Application No. PCT/JP2004/018518, filed Dec. 6,
2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to an indicator lamp comprising a
light-emitting element such as a LED (light-emitting diode) and a
chip and a converging lens disposed atop and covering the
light-emitting element to converge light emitted from the element
and, more particularly, to an indicator lamp, which permits a
small-size light-emitting element to emit light appropriately in a
broad light-emission area and with good efficiency.
[0004] 2. Prior Art
[0005] The light emission zone of a light-emitting element such as
a LED is intrinsically a pin-point. Such pin-point light emission
lacks directivity and is scattered. It is thus impossible to form a
substantially fixed planar light-emission area. Besides, the long
distance visual recognition property is deteriorated. Accordingly,
a converging lens is usually disposed, which covers the front of
the light-emitting element and converges the emitted light.
[0006] An indicator lamp using such a lens is well-known in
Japanese Utility Model Publication H6-28725. This converging lens
has a light-emitting element mounting cavity formed at its bottom,
and its peripheral surface which is parabolic in shape from the
bottom toward the front, fully reflects light emitted from the
light-emitting element such that the reflected light proceeds
forwards.
[0007] The above light-emitting element lens indeed converges light
emitted from the light-emitting element such that the converged
light proceeds straight forward as emission light flux with
suppression of the scattering of light, thus ensuring excellent
long distance visual recognition property. However, since the
scattering of light is suppressed, a problem is posed in that the
visual field angle as visual range is reduced. Particularly, when
the indicator lamp is used as an indicator device, a broad visual
field angle is important as well as the long distance visual
recognition property.
[0008] Besides, the prior art light-emitting element lens has a
structure that the lens front is formed with a deep ring-like
groove such as to form a convex part at the lens front center. The
forming of a lens having such a complicated structure encounters
great difficulty. Particularly, in the case of a lens body having a
certain height, the ring-like groove may become too deep, and
depending on the size and material of the lens, light emitted from
the light-emitting element may not always smoothly and efficiently
proceed as emission light flux forwards.
[0009] To solve the problems as discussed above, it is a primary
object of the invention to provide an indicator lamp, which is
excellent not only in the short distance visual recognition
property but also in the long distance one as well as being further
excellent in the visual field angle property
[0010] A second object of the invention is to provide an indicator
lamp, which permits, without lens shape complication, light emitted
from the light-emitting element to smoothly and efficiently proceed
as emission light flux forwards.
SUMMARY OF THE INVENTION
[0011] To attain the above objects of the invention, an indicator
lamp is provided, which comprises a light-emitting element and a
light-emitting element lens, the light-emitting element lens being
constituted by a lens body formed at the bottom thereof with a
light-emitting element mounting cavity, the light-emitting element
being mounted therein, the lens body having an inverted conical
shape peripheral surface for fully reflecting and re-directing
light emitted from the light-emitting element, the peripheral
surface having varying angles with respect to the lens axis from
the bottom toward the front of the lens, thereby forming one or
more circumferential corners, which scatter light emitted from the
light-emitting element to provide concentric emission light fluxes
as viewed from the side of the lens front.
[0012] The lens body has a convex lens part projecting from the
center of the lens front.
[0013] The lens body has a convex lens part projecting from the
center of the lens front and also has an annular ridge of a
semi-circular sectional profile also projecting from the lens front
such as to surround the convex lens part.
[0014] Another indicator lamp which is provided comprises a
light-emitting element and a lens body with the diameter thereof
increasing as one goes forwardly, the light-emitting element being
disposed at the bottom of the lens body and emitting light to be
fully reflected by the peripheral surface of the lens body and
proceed forwardly thereof, the lens body being formed at the bottom
thereof with a substantially cylindrical cavity accommodating the
light-emitting element, light emitted from the light-emitting
element such as to be directed toward the peripheral surface of the
cavity being incident on the lens body at angles less than the full
reflection angle corresponding to the refractive index of the lens
body, passing through the lens body, and being incident on the
peripheral surface of the lens body to be fully reflected and
proceed forwardly of the lens body, light emitted from the
light-emitting element such as to be directed toward the front
surface of the cavity being incident on the lens body at angles
less than the full reflection angle and passing through the lens
body to directly proceed forwardly of the lens body.
[0015] The front center of the lens body has a convex lens part
projecting forwardly of the lens body and also a flat surface part
extending around the convex lens part, light emitted from the
light-emitting element such as to be directed toward the front
surface of the cavity being incident on the lens at angles less
than the full reflection angle of the lens body, passing through
the lens body, and being converged by the convex lens part to
proceed forwardly of the lens body, light emitted from the
light-emitting element such as to be directed toward the peripheral
surface of the cavity being incident on the lens body at angles
less than the full reflection angle of the lens body to be fully
reflected and proceed forwardly from the flat surface part.
[0016] A further indicator lamp which is proposed comprises a
light-emitting element and a full reflection lens disposed atop the
light-emitting element, the light-emitting element emitting light
to be reflected by the full reflection lens and proceed forwardly
of the full reflection lens, the convex lens part being disposed
atop the light-emitting element, the convex lens part being formed
by charging a transparent polymer material into a frame disposed
such as to surround the light-emitting element from above the frame
such as to be raised in a convex shape.
[0017] The frame is made of a transparent material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view showing a first embodiment of
the indicator lamp according to the invention;
[0019] FIG. 2 is a sectional view showing the first embodiment of
the indicator lamp according to the invention;
[0020] FIG. 3 is a perspective view showing a second embodiment of
the indicator lamp according to the invention;
[0021] FIG. 4 is a sectional view showing the second embodiment of
the indicator lamp according to the invention;
[0022] FIG. 5 is a perspective view showing a third embodiment of
the indicator lamp according to the invention;
[0023] FIG. 6 is a sectional view showing the third embodiment of
the indicator lamp according to the invention;
[0024] FIG. 7 is a perspective view showing a fourth embodiment of
the indicator lamp according to the invention;
[0025] FIG. 8 is a view for describing the optical path in the
fourth embodiment of the indicator lamp according to the
invention;
[0026] FIG. 9 is a view for describing the optical path in a fifth
embodiment of the indicator lamp according to the invention;
[0027] FIG. 10 is a fragmentary sectional view showing a sixth
embodiment of the indicator lamp according to the invention;
[0028] FIG. 11 is a perspective view showing a frame in the sixth
embodiment of the indicator lamp according to the invention;
and
[0029] FIG. 12 is a view for describing the optical path in the
sixth embodiment of the indicator lamp according to the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] FIGS. 1 and 2 show a first embodiment of the indicator lamp
according to the invention. A light-emitting element lens 1 which
is obtained by processing a transparent polymer material into a
substantially conical shape, has a light-emitting element mounting
cavity 3 formed in its bottom for disposing a light-emitting
element 2 such as a LED in the cavity. The lens 1 has a sloped
peripheral surface 4. The angle of the peripheral surface 4 with
respect to the lens axis becomes progressively smaller in three
stages from the bottom toward the front of the lens. The lens front
surface 5 is flat and has a central forwardly convex lens part 6
(R5.78). The lens front surface 5 is made broader by forming a
slightly projecting flange-like edge. As for the three-stage sloped
parts of the peripheral surface 4, their angles with respect to the
lens axis are set up to 40.61 degrees, 32.19 degrees and 26.87
degrees, respectively, (or may be other angles, of course) from the
bottom toward the lens front. The circumferential corners 7 and 8
(points of discontinuity) as boundaries between adjacent ones of
the three-stage sloped parts, provide bright concentric emission
light fluxes as viewed from the side of the lens front.
[0031] FIGS. 3 and 4 show a second embodiment of the indicator lamp
according to the invention. A light-emitting element lens 11 which
is obtained by processing a transparent polymer material into a
substantially conical shape, has a light-emitting element mounting
cavity 12 formed in the bottom for disposing a light-emitting
element 2 such as a LED in the cavity. The lens 11 has a sloped
peripheral surface 13. The angle of the peripheral surface 13
becomes progressively smaller in three stages from the bottom
toward the front of the lens. As for the three-stage sloped parts
of the peripheral surface 13 with respect to the lens axis, like
those in the previous first embodiment, their angles are set up to
40.61 degrees, 32.19 degrees and 26.87 degrees, respectively, (or
may other angles, of course) from the bottom toward the front of
the lens. The lens front surface 14 is flat (which is made broader
by forming a slightly projecting flange-like edge), and has a
central forwardly convex lens part 15 having a smaller diameter
than the diameter of the lens front surface 14. The convex lens
part 15 has a stem part and a front part with a reduced radius of
curvature compared to the stem part. Specifically, the radius of
curvature of the stem part is set up to R5.14, and the radius of
curvature of the front part is set up to R4.65. The circumferential
corners 16 and 17 (points of discontinuity) as boundaries between
adjacent ones of the three-stage sloped parts and the
radius-of-curvature boundary 18 of the convex lens part 15, provide
bright concentric emission light fluxes as viewed from the side of
the lens front.
[0032] FIGS. 5 and 6 show a third embodiment of the indicator lamp
according to the invention. In this embodiment, the light-emitting
element lens 21 is a modification of the light-emitting element 1
in the first embodiment. The lens 21 has a light-emitting element
mounting cavity 22 formed at the bottom for disposing the
light-emitting element 2 such as a LED in the cavity. The
peripheral surface 23 of the lens has its slope angle with respect
to the lens axis reduced in three stages from the bottom toward the
front of the lens. As for the three-stage sloped parts of the
peripheral surface 23, their angles with respect to the lens axis
are again set up to 40.61 degrees, 32.19 degrees and 26.87 degrees,
respectively, (or may be other angles, of coursed) from the bottom
toward the front of the lens. The lens front surface 24 is
basically flat, but it has a central forwardly convex lens part 25
having a diameter smaller than the diameter of the lens front
surface 24, and also has a ring-like ridge 26 having a
semi-circular sectional profile and surrounding the lens part 25.
The circumferential boundaries 27 and 28 between adjacent ones of
the three-stage sloped parts and the boundaries 29 and 30 of the
ridge 26 with respect to the flat part of the lens front surface
24, provide bright concentric emission light fluxes as viewed from
the side of the lens front.
[0033] In the above embodiments, the peripheral surface of the lens
is formed with two circumferential corners as boundaries between
adjacent ones of the sloped parts. However, this is by no means
limitative; for example, it is possible as well to provide a single
corner or three or more corners.
[0034] FIGS. 7 and 8 show a fourth embodiment of the indicator lamp
according to the invention. In this embodiment, the light-emitting
element lens 31, which is made of a transparent polymer material
such as acrylic resin and has a maximum outer diameter of about 21
mm and a height of about 12.5 mm, has an inverted conical shape
with the outer diameter thereof increasing as one goes upwards. The
light-emitting element 2 is disposed at the bottom of the lens, and
its emitted light is converged and proceeds as a certain degree of
emission light flux forwardly of the lens. This light-emitting
element lens 31 has a peculiarly curved peripheral surface slightly
outwardly swelling from the bottom towards the front surface 34 of
the lens (a plurality of slipped surface parts being possible
instead of the curved peripheral surface). The lens front surface
34 has an outer flat surface part 35 and a central forwardly convex
lens part 36 (R5) forwardly projecting from a position slightly on
the rear side of the lens front surface 34.
[0035] The light-emitting element 1 has its bottom formed with a
substantially cylindrical cavity 37 having a height sufficient
enough to dispose the light-emitting element 2 in the cavity. (In
the prior art light-emitting element lens described above, the lens
bottom is formed with a mere semi-spherical cavity having a small
diameter needed to merely dispose the light-emitting element.) The
cavity 37 has a spherical front surface 37a (R4), which is convex
forwardly of the lens. The cavity 37 also has a slightly tapered
peripheral surface 37b with the diameter thereof progressively
reduced as one goes from the lens bottom toward the lens front. The
cavity 37 thus has a substantially cylindrical shape. The diameter,
height and taper of the cavity 37 are set up depending on the
dimensions of the disposed light-emitting element 2, the refractive
index corresponding to the lens material and the outer lens
dimensions, etc.
[0036] With the light-emitting element lens 31 having the above
structure, as shown in FIG. 8, light emitted from the
light-emitting element 2 toward the convex front surface 37a of the
cavity, is incident substantially at right angles (below the full
reflection angle corresponding to the refractive index of the lens)
on the front surface 37a, then proceeds straight through the lens,
and is refracted to be converged by the convex lens part 36 of the
lens front surface 34 and become an emission light flux proceeding
forwardly of the lens. In this embodiment, light passing through
the convex lens part 36 is rendered to be a parallel light flux by
setting up the radius of curvature of the convex lens part 36 to
the refractive index of the acrylic resin lens. Light emitted from
the light-emitting element 2 toward the peripheral surface 37b of
the cavity 37, is incident at the full reflection angle
corresponding to the refractive index of the lens on the peripheral
surface 37b to be diffracted, then is incident at angles not below
the above full reflection angle to be fully reflected, and then is
passed through the flat surface part 35 of the lens front surface
34 to proceed as emission light flux forwardly of the lens.
[0037] FIG. 9 is a view showing a fifth embodiment of the indicator
lamp according to the invention. In this embodiment, the
light-emitting element lens 41, unlike the lens in the preceding
fourth embodiment, has a fully flat front surface free from any
convex lens part. For the remainder, this embodiment is the same as
the fourth embodiment. With this light-emitting element lens 41,
light emitted from the light-emitting element 2 toward the front
surface 42a of the cavity 42, is incident substantially at right
angles on the front surface 42a, then proceeds as emission light
flux through the lens, and is then diffracted by the lens font
surface 43 toward the lens axis to become an emission light flux
proceeding forwardly of the lens. Light emitted from the
light-emitting element 3 toward the peripheral surface 42b of the
cavity 42, is incident at angles below the full reflection angle
corresponding to the refractive index of the lens on the peripheral
surface 42b to be refracted, then is incident at angles not below
the full reflection angle on the peripheral surface 44 to be fully
reflected, and then proceeds through the lens front surface 43 to
become an emission light flux proceeding forwardly of the lens.
This lens 41, although not providing a perfectly parallel light
flux as in the case of the light-emitting element lens 31 in the
fourth embodiment, can provide a converging function to provide a
roughly parallel light flux of a simple shape. Although not
illustrated, with such an arrangement that light is not caused by
the front surface 42a of the cavity 42 to proceed straight but is
diffracted for deviation toward the lens axis, it is possible to
provide a more suitable converging function to provide light close
to a parallel light flux.
[0038] FIGS. 10 to 12 show a sixth embodiment of the indicator lamp
according to the invention. In this embodiment, the light-emitting
element lens 61 is a modification of the light-emitting element
lens 31 in the fourth embodiment in view of the disposition of the
light-emitting element 2. FIG. 10 shows a half-split structure of
the indicator lamp 61. The indicator lamp 61 comprises a
light-emitting element 63 such as a LED disposed on a base 62
formed with a wiring pattern, a full reflection lens 64 and a
non-transparent cylindrical cover 65. The full reflection lens 64
is disposed atop the light-emitting element 63, is made of a
transparent polymer material such as an acrylic resin, and has a
substantially inverse conical shape with the diameter thereof
progressively increasing as one goes forwards and having a maximum
outer diameter of about 21 mm and a height of about 12.5 mm. The
cylindrical cover 65 is disposed on the base 62 so as to surround
the peripheral surface of the full reflection lens 64 while holding
a front part thereof.
[0039] FIG. 11 is a half-split perspective view showing the lens
structure in the neighborhood of the light-emitting element 63. A
substantially ring-like frame 66 made of a transparent acrylic
resin surrounds the small diameter light-emitting element 63
disposed on the base 62. Transparent molten silicone or like
polymer material is charged down into the frame such as to cover
the light-emitting element 63 and also be swelled to a convex shape
by the surface tension, and is hardened, thus forming a convex lens
part 67. The frame 66 serves as a die for charging molten polymer
material into it, and is transparent in it to transmit light from
the light-emitting element 63 without leakage. The convex lens part
67 has a function of converging light emitted from the
light-emitting element to a certain extent and also a function of
protecting the light-emitting element 63 and bonding wires (not
shown) connecting the light-emitting element 63 and patterns on the
base 62. It is possible to obtain a desired radius of curvature of
the convex lens part 67 by controlling the quantity of the polymer
material charged into the frame 66 to a constant quantity. In the
prior art, the light-emitting element and the bonding wires were
coated with silicon warmish by using a brush. In this method, the
light emitted from the light-emitting element and reaching the lens
body is non-uniform, and consequently it was impossible to obtain
suitable converging such as parallel light flux. The resin part
covering the light-emitting element 63 is made to be large in
diameter, and the diameter of the cavity 68 is correspondingly made
to be large. However, making the diameter of the cavity 68 large as
a whole has great adverse effects on the optical path of light
reflected by the lens peripheral surface. To avoid this, a least
necessary structure size is set up. Also, the cavity 68 is formed
with a stepped extension surface 69 in a bottom part to increase
the diameter thereof alone without changing the size of the
remainder, i.e., the front part. However, by forming the stepped
extension surface 69 simply as a horizontal surface, light emitted
from the light-emitting element 63 is diffracted by the stepped
extension surface 69 to provide unintended optical path different
from the optical path in the fourth embodiment. The stepped
extension surface 69 is made to be an outwardly upward taper lest
light emitted from the light-emitting element 63 should be incident
on the stepped extension 69.
[0040] In the indicator lamp 61 having the above structure, as
shown in FIG. 12, light emitted from the light-emitting element 63
is converged to a certain extent as it is transmitted through the
convex lens part 67 covering the light-emitting element, and then
proceeds through the cavity 68. Light directed from the convex lens
part 67 toward the front surface 68a of the cavity 68 is incident
on the curved front surface 68a substantially at right angles
(below the full reflection angle corresponding to the radius of
curvature of the lens), proceeds through the lens body straight,
and is diffracted to be converged by the central convex lens part
70 of the lens front surface and become an emission light flex
proceeding forwardly of the lens. In this embodiment, light passing
through the convex lens part 67 is made to be a parallel light flux
by setting up the radius of curvature of the convex lens part 67
according to the diffractive index of the acrylic resin lens. Light
directed from the convex lens part 67 toward the peripheral surface
68b of the cavity 68, is incident at angles below the full
reflection angle corresponding to the refractive index of the lens
on the peripheral surface 68b to be diffracted, then is incident at
angles not below the above full reflection angle on the peripheral
surface 71 to be fully reflected, and then proceeds through the
flat surface part 72 of the lens front surface to become an
emission light flux proceeding forwardly of the lens.
[0041] While the above embodiment is concerned with the structure
that the central convex lens part 70 is provided on the front
surface of the full reflection lens 64, this is by no means
limitative; for instance, the lens front surface may be made fully
flat and free from any central convex lens part. Even in this case,
although not a perfect parallel light flux as in the case of the
fifth embodiment of the indicator lamp 61 described above, this
embodiment of the indicator lamp can provide a converging function
to provide a roughly parallel light flux of a simple shape.
Although not illustrated, with such an arrangement that light is
not caused by the front surface 68a of the cavity 68 to proceed
straight but diffracted for deviation toward the lens axis, it is
possible to provide a more suitable converging function to provide
light close to a parallel light flux.
[0042] Possibility of Industrial Utilization
[0043] In the indicator lamp according to the invention, the
light-emitting element lens is constituted by a light-emitting
element mounting cavity, the light-emitting element being mounted
therein, the lens body having an inverted conical shape peripheral
surface for fully reflecting and forwardly re-directing light
emitted from the light-emitting element, the peripheral surface
having varying angles with respect to the lens axis from the bottom
toward the front of the lens, thereby forming one or more
circumferential corners, which scatter light emitted from the
light-emitting element forwardly to provide concentric emission
light fluxes as viewed from the lens front side. Thus, a planar
light flux resulting from full reflection by the peripheral surface
and concentric ring-like light fluxes brighter than the planar
light flux are combined together to form resultant light emitted
from the front surface of the lens. It is thus possible to obtain
excellent visual recognition property not only in the short
distance but also in the long distance owing to the ring-like light
fluxes.
[0044] The lens body has a convex lens part projecting from the
center of the lens front. Thus, light which is not reflected by the
lens body peripheral surface but is directly transmitted through
the central part of the lens, is converged by the convex lens part,
thus permitting more suppression of scattering and light emission
up to a more remote place. Also, at the boundary between the lens
front surface and the convex lens part, light emitted from the
light-emitting element is collected more than it is collected at
the other lens front part to form a bright ring-like light flux
emitted from the lens front. It is thus possible to improve the
visual recognition property not only in the short distance but also
in the long distance.
[0045] The lens body has a convex lens part projecting from the
center of the lens and also has an annular ridge of a semi-circular
sectional profile also projecting from the lens front such as to
surround the convex lens part. Thus, light which is neither
reflected by the lens body peripheral surface nor transmitted
through the convex lens part but is merely transmitted through the
convex lens part outer periphery, is further converged by the above
ridge, thus permitting more suppression of scattering and light
emission up to a more remote place. Double concentric boundaries
between the lens front surface and the ridge, collect more light
emitted from the light-emitting element than the other part of the
lens front to provide bright ring-like light fluxes emitted from
the lens front. It is thus possible to further improve the visual
recognition property not only in the short distance but also in the
long distance.
[0046] Furthermore, according to the invention the indicator lamp
comprises a light-emitting element and a lens body with the
diameter thereof increasing as one goes forwards, the
light-emitting element being disposed at the bottom of the lens
body and emitting light to be fully reflected by the peripheral
surface of the lens body and proceed forwardly thereof, the lens
body being formed at the bottom thereof with a substantially
cylindrical cavity accommodating the light-emitting element, light
emitted from the light-emitting element such as to be directed
toward the peripheral surface of the cavity being incident on the
lens body at angles less than the full reflection angle
corresponding to the reference index of the lens body passing
through the lens, and being incident on he peripheral surface of
the lens body to be fully reflected and proceed forwardly of the
lens body, light emitted from the light-emitting element such as to
be directed toward the surface of the cavity being incident on the
lens body at angles less than the full reflection angle and passing
through the lens body to directly proceed forwardly of the lens
body. Thus, light emitted from the light-emitting element is split
into a light flux passing through the front surface of the cavity
and a light flux passing through the peripheral surface, and the
light flux passing through the peripheral surface of the cavity is
suitably fully reflected by the lens body peripheral surface
according to the radius of curvature of the lens body, and suitably
proceed as an emission light flux forwardly of the lens body.
[0047] The front center of the lens body has a convex lens part
projecting forwardly of the lens body and also a flat surface part
extending around the convex lens part, light emitted from the
light-emitting element such as to be directed toward the front
surface of the cavity being incident on the lens body at angles
less than the full reflection angle of the lens body, passing
through the lens body and being converted by the convex lens part
to proceed forwardly of the lens body, light emitted from the
light-emitting element such as to be directed toward the peripheral
surface of the cavity being incident on the lens at angles less
than the full reflection angle of the lens body to be fully
reflected and proceed forwardly from the flat surface part. Thus,
light passing through the front surface of the cavity is collected
in the convex lens part, and light passing through the peripheral
surface of the cavity is fully reflected by the lens body
peripheral surface to be emitted as a suitable emission light flux
forwardly of the lens body.
[0048] Moreover, according to the invention the indicator lamp
comprises a light-emitting element and a full reflection lens
disposed atop the light-emitting element, the light-emitting
element emitting light to be reflected by the full reflection lens
and proceed forwardly of the full reflection lens, the convex lens
part being disposed atop the light-emitting element, the convex
lens part being formed by charging a transparent polymer material
into a frame disposed such as to surround the light-emitting
element from above the frame such as to be raised in a convex
shape. Thus, the light-emitting element and bonding wires connected
thereto are protected by the transparent polymer material. Also,
light emitted from the light-emitting element is collected by
swelling convex lens part to become a suitable emission light flux
proceeding toward the full reflection lens. It is thus possible
that light emitted from the light-emitting element can smoothly and
efficiently proceed as mission light flux forwardly of the full
reflection lens.
[0049] With the frame made of a transparent material, light emitted
from the light-emitting element toward the frame can proceed toward
the full reflection lens without being blocked by the frame. Thus,
it is possible to obtain efficient light emission.
* * * * *