Optical: systems and elements – Signal reflector – 3-corner retroreflective
Reexamination Certificate
2000-03-29
2001-09-18
Phan, James (Department: 2872)
Optical: systems and elements
Signal reflector
3-corner retroreflective
C359S574000, C359S552000, C404S006000, C404S007000, C404S009000
Reexamination Certificate
active
06290362
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a delineator and, more specifically, a delineator attached to an object such as a guardrail placed along the road for giving a notice to the driver as to where the road leads to.
2. Description of the Background Art
A delineator has been conventionally known which is attached to a guardrail or a wall surface provided along the road for giving notice to the driver, by reflecting light from a head lamp of a car, for example, to a direction opposite to the incident direction.
FIG. 14
illustrates the function of such a delineator
300
. Referring to the figure, delineator
300
includes a mirror finished surface portion (refracting surface)
109
, and reflects incident light beam from perpendicular direction
112
of mirror finished surface portion
109
to the opposite direction. The angle within which the incident light beam can be reflected (effective incident angle) is
20
° each in left and right directions with respect to perpendicular
112
of the mirror finished surface portion.
FIG. 15
is a cross section showing the mechanism of light reflection of delineator
300
. Referring to the figure, delineator
300
has a plurality of reflex reflecting elements
103
therein. Reflex reflecting element
103
is a cubic corner element formed of a transparent acrylic resin, for example. As denoted by the arrows in the figure, the light beam entering through mirror finished surface portion
109
is reflected by the surfaces of reflex reflecting element
103
and output in the direction opposite to the incident direction.
FIG. 16
is a plan view showing such delineators
300
attached on the road
201
. In this example, delineators
300
are attached at a T intersection of the road
201
. Light beams from the head lamp of a vehicle
200
coming near to the T intersection are reflected by delineators
300
. This helps the driver of vehicle
200
to notice the existence of the wall ahead.
Similarly, at a sharp curve of the road
201
such as shown in
FIG. 17
, the driver notices the curve as the light beams from the headlight of vehicle
200
are reflected.
The conventional delineator, however, suffers from the following problem.
Referring to
FIG. 18
, if the road
201
curves moderately (or if the road
201
runs straight), the light beams from the headlight of a running vehicle
200
cannot be reflected by delineator
300
even when delineator
300
is attached to the sidewall or a guardrail along the road, as the effective incident angle of the delineator is as narrow as ±20°, as described with reference to FIG.
14
.
A delineator having such a structure as shown in
FIG. 19
has been known as a solution of the above described problem, which is capable of reflecting light beams from the vehicle even at a moderate curve or straight road.
Referring to
FIG. 19
, delineator
300
includes, in addition to reflex reflecting elements
103
arranged parallel to each other on mirror finished surface portion
109
, a projection
301
on the side of mirror finished surface portion
109
. Because of this projection
301
, a light beam proceeding parallel to mirror finished surface portion
109
is reflected by reflex reflecting element
103
through projection
301
, and again reflected through projection
301
to the direction opposite to the incident direction. Accordingly, not only the light beams entering perpendicularly but also light beams proceeding parallel to the mirror finished surface portion
109
can effectively be reflected.
However, in such a delineator, not all of the light beams entering from a direction parallel to the mirror finished surface portion
109
are reflected by projection
301
, and some of the light beams are transmitted through projection
301
. As a result, intensity of the reflected light beams is low.
SUMMARY OF THE INVENTION
The present invention was made to solve the above described problems and its object is to provide a delineator which can be readily noticed by the driver even if the road runs straight or curves moderately.
The above described object is attained by a delineator in accordance with an aspect of the present invention attached to an object existing along a road, which includes a deflecting portion having a plurality of reflex reflecting elements for reflecting incident light beams in a direction opposite to the incident direction, with a refracting surface of the reflecting portion and an optical axis of the reflex reflecting element being inclined in the direction to which the road leads.
According to another aspect of the present invention, the delineator attached to an object existing along the road includes a plurality of reflecting portions and a base having a surface on which the plurality of reflecting portions are attached side by side, each of the plurality of reflecting portions having a reflex reflecting element, and refracting surface of the plurality of reflecting portions being inclined from the surface on which the reflecting portions are attached side by side.
Preferably, the plurality of reflecting portions include a first reflecting portion attached with its refracting surface inclined in a first direction with respect to the surface on which the reflecting portions are attached side by side, and a second reflecting portion attached with its refracting surface inclined in the direction opposite to the first direction with respect to the surface on which the reflecting portions are attached side by side.
More preferably, the first and second reflecting portions are different in color with each other.
More preferably, the reflex reflecting element included in each of the reflecting portion has its optical axis inclined in the same direction of inclination as the refracting surface.
More preferably, said base includes a guardrail.
More preferably, the base includes a double sided adhesive tape.
More preferably, the plurality of reflecting portions are attached on the base by a rail member.
According to the invention, the direction in which the delineator reflects light beams can be inclined, and therefore a delineator which can be easily noticed by the driver even if the road is straight or curves moderately can be provided.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 4349598 (1982-09-01), White
patent: 5049001 (1991-09-01), Dinitz
Cateye Co. Ltd.
Olson & Hierl Ltd.
Phan James
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