Optical switch

Details Optical switch Optical switch

2003-02-25

2004-12-07

Kang, Juliana K. (Department: 2874)

Optical waveguides

With optical coupler

Switch

C385S015000, C385S016000, C385S031000, C385S036000

Reexamination Certificate

active

06829404

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to an optical switch for switching a combination of light paths between a plurality of optical fibers.
BACKGROUND OF THE INVENTION
In common, an optical switch is provided for switching the light path between collimate lenses optically coupled to corresponding optical fibers by a prism advancing and retracting between two set of the lenses. Some of such conventional optical switches are disclosed having an electromagnetic driver equipped with an armature which is mechanically joined to the prism (U.S. Pat. No. 5,999,669 and JP Patent Laid-open Publication 4-145409).
The optical switch disclosed in U.S. Pat. No. 5,999,669 has a prism
31
arranged to move to and from between collimate lenses
35
, which are optically coupled to corresponding optical fibers
4
a
to
4
c
and located at their position in a body
1
, for switching the light path, as shown in FIG.
57
. The prism
31
is mounted to one end of an arm
37
which is joined at the other end to and driven by a relay RY for rotation. As a result, the prism
31
is moved vertically of the sheet of paper to and from the light path. When the prism
31
is retracted from the light path, the two optical fibers
4
a
and
4
c
are coupled. When the prism
31
is set across the light path, the optical fiber
4
a
is coupled to the optical fiber
4
b.
The optical switch disclosed in JP Patent Laid-open Publication 4-145409 has a prism
31
arranged to move in and from between collimate lenses
35
, which are optically coupled to corresponding optical fibers
4
a
,
4
b
,
4
c
, and
4
d
, through the window
38
e
provided in an iron core for switching the light path, as shown in FIG.
58
. The prism
31
is actuated by a mechanism which has a leaf spring
38
a
joined at one end to a permanent magnet
38
b
and the prism
31
and at the other end to the iron core
38
c
. The iron core
38
c
has a coil
38
d
wound thereon. When the coil
38
d
is energized, a magnetic force is developed between the permanent magnet
38
b
and the iron core
38
c
thus to move the prism
31
to and from the light path vertically of the sheet of paper. When the prism
31
is retracted from the light path, the optical fibers
4
a
and
4
b
are coupled to the optical fibers
4
c
and
4
d
respectively. When the prism
31
is present across the light path, the optical fibers
4
a
and
4
d
are coupled to each other while the optical fibers
4
b
and
4
c
are coupled to each other.
In either the conventional optical switch, the prism
31
is mounted to the arm
37
or the leaf spring
38
a
which extends at a right angle to the moving direction of the prism
31
. Also, as the arm
37
or the leaf spring
38
a
performs a pivotal movement about one pivot, its length has to be increased for extending the stroke of the movement of the prism
31
.
As a result, the body
1
will be increased in the size along the lengthwise direction of the arm
37
or the leaf spring
38
a
. Also, the body
1
may have an unwanted dead space in the interior thereof. Since the prism
31
is pivotably moved about the pivot on the arm
37
or the leaf spring
38
a
, its pivotal movement permits the area of the prism
31
adjacent to the center thereof to be off the light path and causes the outermost of the prism
31
to travel a long distance. Accordingly, a more space will be needed for clearing the movement of the prism
31
, hence increasing the overall size of the body
1
.
SUMMARY OF THE INVENTION
It is hence an object of the present invention to provide an optical switch which is decreased in the overall size with any dead space minimized in its body.
In order to achieve the above-mentioned object, according to the present invention, an optical switch for switching the light path between collimate lenses optically coupled to the ends of corresponding optical fibers by the advancing and retracting movements of a prism, comprises: a body incorporating an optical switch housing; an electromagnetic driver having an armature arranged to hold the prism and a coil block for driving the movement of the armature by means of magnetic actions; and a leaf spring resilient in the moving direction of the armature consisting mainly of at least two parallelly extending spring strips, each of the spring strips is fixedly mounted at one end to the body and at the other end to the armature thus to spatially hold the armature and the prism for linear movement. The electromagnetic driver and the prism are disposed next to each other along the moving direction of the armature, and the armature and the prism can linearly be moved at a right angle to the light path between the lenses when the optical switch is in action.
As one feature of the present invention, the electromagnetic driver allows the armature and thus the prism to move linearly. Also, the electromagnetic driver is located next to the prism along the moving direction of the armature. Accordingly, the size for advancing and retracting the prism is determined simply by the area of the prism projected on a place orthogonal to the moving direction of the armature. As a result, the mechanism for switching the light path can be minimized in the dimensions. Also, as the movement of the prism is linear, unlike the conventional pivotal movement about a pivot point on a member to which the prism is mounted, any dead apace for clearing the movement of the prism will be eliminated. Consequently, the body can be decreased in the overall size.
In the optical switch of the present invention, the coil block in the electromagnetic driver comprises an iron core having two magnetic polar portions provided at both ends thereof, a coil for exciting the iron core, and a permanent magnet for magnetizing the armature, the armature comprises a first contact portion located opposite to one side of one of the two magnetic polar portions which faces one direction of the movement of the armature and a second contact portion located opposite to one side of the other magnetic polar portion which faces the other direction of the movement of the armature, and each of the spring strips is joined to an intermediate region between the two contact portions of the armature. As the electromagnetic driver is of a polar type, it can generate a large driving force from a relatively small level of current thus contributing to the energy saving.
In the optical switch of the present invention, the electromagnetic driver performs a bistable action for holding the armature by the magnetic force of the permanent magnet at each of the two positions, where the first contact portion of the armature comes into direct contact with the corresponding polar portion of the iron core and where the second contact portion of the armature comes into direct contact with the other polar portion of the iron core. As the electromagnetic driver performs the bistable action, its coil has to be energized only when the switching of the light path is required hence minimizing the consumption of power.
In the optical switch of the present invention, the electromagnetic driver performs a monostable action for holding the armature by the magnetic force of the permanent magnet constantly at one of the two positions, where the first contact portion of the armature comes into direct contact with the corresponding polar portion of the iron core or where the second contact portion of the armature comes into direct contact with the other polar portion of the iron core. As the electromagnetic driver performs the monostable action, its coil needs not to be energized while normally connected one of the light path is selected hence minimizing the consumption of power.
In the optical switch of the present invention, the number of the spring strips is four, and the armature is arranged between two pairs of the spring strips, each pair extending in one direction from each joint with the armature to one of the magnetic polar portion. As the armature is supported at both ends along the direction across the two polar portions of the iron core, its moveme

Affiliated with

Also associated with

Rating

Optical switch does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Optical switch, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical switch will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3305492