U.S. patent application number 09/859393 was filed with the patent office on 2002-04-18 for mirror support structure.
Invention is credited to Mukae, Hisayuki.
Application Number | 20020044366 09/859393 |
Document ID | / |
Family ID | 18792868 |
Filed Date | 2002-04-18 |
United States Patent
Application |
20020044366 |
Kind Code |
A1 |
Mukae, Hisayuki |
April 18, 2002 |
MIRROR SUPPORT STRUCTURE
Abstract
A light-weight and highly rigid mirror support structure is
provided which is capable of maintaining a relation between the
relative positions of a main mirror and an auxiliary mirror even
with environmental variations in the place of installation or
deformations of a mounting surface, and of preventing a deformation
of the main mirror and the auxiliary mirror which would otherwise
cause performance deterioration. A main mirror (1) and an auxiliary
mirror (2) are disposed a predetermined distance apart from each
other in a face-to-face relation. A main mirror support member (3)
and an auxiliary mirror support member (4) serve to support the
main mirror (1) and the auxiliary mirror (2), respectively. A
plurality of rods (15a) connect the main mirror support member (4)
and the auxiliary mirror support member (4) with each other. A
plurality of auxiliary rods (15b) are joined at one ends thereof to
the main mirror support member (3) or the auxiliary mirror support
member (4) and at the other ends thereof to a single connection
point (A). A plurality of support legs (26) indirectly support the
first and auxiliary mirrors (1), (2) at a total of three points
including two points on the main mirror support member (3) and the
single connection point (A) at which the auxiliary rods (15b) are
joined together. The support legs (26) are fixedly mounted on a
base panel (7). The support legs (26) are composed of follower
members capable of following an expansion or contraction of the
base panel (7).
Inventors: |
Mukae, Hisayuki; (Tokyo,
JP) |
Correspondence
Address: |
Platon N. Mandros
BURNS, DOANE, SWECKER & MATHIS, L.L.P.
P.O. Box 1404
Alexandria
VA
22313-1404
US
|
Family ID: |
18792868 |
Appl. No.: |
09/859393 |
Filed: |
May 18, 2001 |
Current U.S.
Class: |
359/881 ;
359/838; 359/871; 359/879 |
Current CPC
Class: |
G02B 7/183 20130101 |
Class at
Publication: |
359/881 ;
359/838; 359/871; 359/879 |
International
Class: |
G02B 007/182; G02B
005/08 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 13, 2000 |
JP |
2000-313452 |
Claims
What is claimed is:
1. A mirror support structure comprising: a first mirror and a
second mirror disposed a predetermined distance apart from each
other in a face-to-face relation; a first mirror support member and
a second mirror support member supporting said first mirror and
said second mirror, respectively; a plurality of main rods
connecting said first mirror support member and said second mirror
support member with each other; a plurality of auxiliary rods
joined at one ends thereof to said first mirror support member or
said second mirror support member and at the other ends thereof to
a single connection point; a plurality of support legs for
indirectly supporting said first and second mirrors at a total of
three points including two points on said first mirror support
member and said single connection point at which said auxiliary
rods are joined together; and a base on which said support legs are
fixedly mounted; wherein said support legs are composed of follower
members capable of following an expansion or contraction of said
base.
2. The mirror support structure as claimed in claim 1, wherein said
first mirror support member and said second mirror support member
are each composed of a triangular-shaped panel, and said main rods
and said auxiliary rods comprise three pairs of main and auxiliary
rods joined together in each pair to form a continuous and integral
rectilinear configuration, said three pairs of continuously and
integrally joined main and auxiliary rods serving to connect three
apexes of said first triangular-shaped mirror support member with
three corresponding apexes of said second triangular-shaped mirror
support member, respectively, to cooperate with three sides of said
first triangular-shaped mirror support member and three sides of
said second triangular-shaped mirror support member to form a
trussed structure.
3. The mirror support structure as claimed in claim 2, wherein said
main rods comprise additional main rods connecting three apexes of
said first triangular-shaped mirror support member with three
different apexes of said second triangular-shaped mirror support
member in combinations different from those in which the three
apexes of said first triangular-shaped mirror support member and
the three corresponding apexes of said second triangular-shaped
mirror support member are connected with each other by means of
said three pairs of continuous and integrally joined main and
auxiliary rods.
4. The mirror support structure as claimed in claim 1, wherein said
first mirror support member and said second mirror support member
are each composed of a triangular-shaped panel, and said main rods
comprise six main rods connecting three apexes of said first mirror
support member and three apexes of said second mirror support
member, respectively, and said auxiliary rods comprise three
auxiliary rods joined to three apexes of said second mirror support
member, respectively, said six main rods and said three auxiliary
rods cooperating with three sides of said first triangular-shaped
mirror support member and three sides of said second
triangular-shaped mirror support member to form a trussed
structure.
5. The mirror support structure as claimed in claim 1, wherein said
first mirror support member and said second mirror support member
are each composed of a triangular-shaped panel, and said first
triangular-shaped mirror support member and said second
triangular-shaped mirror support member are arranged such that they
have one side disposed in parallel with a surface of said base, and
said main rods comprise six main rods connecting three apexes of
said first triangular-shaped mirror support member and three apexes
of said second triangular-shaped mirror support member with each
other, and said auxiliary rods comprise three auxiliary rods joined
to the three apexes of said first triangular-shaped mirror support
member, respectively, said six main rods and said three auxiliary
rods cooperating with three sides of said first triangular-shaped
mirror support member and three sides of said second
triangular-shaped mirror support member to form a trussed
structure.
6. The mirror support structure as claimed in claim 1, wherein said
first mirror support member and said second mirror support member
are each composed of a triangular-shaped panel, and said first
triangular-shaped mirror support member and said second
triangular-shaped mirror support member are arranged such that they
have each side disposed in antiparallel with a surface of said
base, and said main rods comprise six main rods connecting three
apexes of said first triangular-shaped mirror support member and
three apexes of said second triangular-shaped mirror support member
with each other, and said auxiliary rods comprise three auxiliary
rods joined to three apexes of said first triangular-shaped mirror
support member, respectively, said six main rods and said three
auxiliary rods cooperating with three sides of said first
triangular-shaped mirror support member and three sides of said
second triangular-shaped mirror support member to form a trussed
structure.
7. The mirror support structure as claimed in claim 1, wherein said
follower members are each composed of a plate spring.
Description
[0001] This application is based on Application No. 2000-313452
filed on Oct. 13, 2000, the contents of which are hereby
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a mirror support structure
for an optical sensor for sensing light or radio waves or an
antenna for transmitting and receiving light or radio waves, which
are adapted to be mounted on a moving object such as a satellite,
or which are used under severe environmental conditions such as
great temperature changes.
[0004] 2. Description of the Related Art
[0005] FIG. 6 illustrates one example of such a known mirror
support structure. In this figure, the known mirror support
structure includes a main mirror 1, an auxiliary mirror 2 disposed
in a face-to-face and spaced-apart relation with respect to the
main mirror 1, a main mirror support member 3 in the shape of a
triangular configuration with the main mirror 1 fixedly secured
thereto, an auxiliary mirror support member 4 also of a triangular
configuration with the auxiliary mirror 2 fixedly secured thereto,
a plurality of rods 5 connecting the respective apexes of the
triangular-shaped main mirror support member 3 and the respective
apexes of the triangular-shaped auxiliary mirror support member 4,
a plurality of support legs 6 supporting thereon the main mirror
support member 3 and the auxiliary mirror support member 4, and a
base panel 7 on which the support legs 6 are fixedly mounted.
[0006] With such a mirror support structure, the main mirror
support member 3 and the auxiliary mirror support member 4 are
arranged on the base panel 7 in such a manner that the relative
positions of the main mirror 1 and the auxiliary mirror 2 can be
placed in an optimal relation with respect to each other. The
respective apexes of the main mirror support member 3 and the
respective apexes of the auxiliary mirror support member 4 are
connected with each other by means of the respective rods 5 so as
to maintain the optimal relation between the primary and auxiliary
mirrors 1, 2. In addition, the support legs 6 are secured at one
ends thereof to the main mirror support member 3 or the auxiliary
mirror support member 4 and fixedly mounted at the other ends
thereof on the base panel 7. For example, in the case of an optical
sensor to be installed on a satellite, it is possible to mount the
optical sensor on the satellite with a predetermined arrangement by
positioning the base panel 7 in place on the satellite.
[0007] Moreover, FIG. 7 illustrates another example of a known
mirror support structure. A main mirror support member 13 formed of
a quadrangular panel is directly fixed to a base panel 7, and a
plurality of support legs 16 each in the form of a rod serve to
connect the opposite upper corner portions of the main mirror
support member 13 and the base panel 7 with each other.
[0008] With the enhanced observation performance of optical sensors
or radio wave sensors, and the improved performance of antennae due
to the increasing transmission capacity of communications equipment
in recent years, there has been a problem that the performances of
the optical or radio wave sensors or antennae are adversely
affected by the displacement or deformation of the mirror support
structure caused by dimensional changes or environmental variations
in the mirror support structure for maintaining the relative
positional relation between the main mirror 1 and the auxiliary
mirror 2.
[0009] That is, with the mirror support structure shown in FIG. 6,
the dimensional change (expansions or contractions) and/or
distortion of a mounting surface, to which the base panel 7 is
fixedly secured, due to temperature changes would alter the
relative positions or angles of the plurality of support legs 6,
thus changing the relation between the relative positions of the
main mirror support member 3 and the auxiliary mirror support
member 4. As a result, there arises a problem in that the main
mirror 1 and the auxiliary mirror 2 become unable to maintain the
prescribed relation between their relative positions.
[0010] Furthermore, in the case of the known example of FIG. 7, in
which the support legs 16 are only connected with the main mirror
support member 13 but not with the auxiliary mirror support member
4, there is no such a problem as referred to above that the
relative positions of the main mirror 1 and the auxiliary mirror 2
would be caused to change due to the expansion or contraction of
the base panel 7. In this case, however, there arises another
problem that the main mirror support member 13 would be caused to
expand and contract or distort and deform due to external forces
applied thereto by the connection portions thereof with the base
panel 7 and/or the plurality of support legs 16, thus giving rise
to adverse influences on the main mirror 1 mounted on the main
mirror support member 13.
[0011] Besides, when a sensor or antenna is to be installed on an
satellite, it is necessary to achieve a mirror support structure
that is light in weight and high in rigidity, in order to avoid
deterioration in performance which would otherwise be caused by
vibrations during movement or launching thereof through a
rocket.
SUMMARY OF THE INVENTION
[0012] The present invention is intended to obviate the
above-mentioned problems, and has for its object to provide a
light-weight and highly rigid mirror support structure of the
character as described which is capable of maintaining, even with
environmental variations in the place of installation and/or
deformations of a mounting surface of a base panel, the relation
between the relative positions of a main mirror and an auxiliary
mirror in a proper manner, and of avoiding the deformation of the
primary and auxiliary mirrors which would result in deterioration
of the performance.
[0013] Bearing the above object in mind, according to the present
invention, there is provided a mirror support structure comprising:
a first mirror and a second mirror disposed a predetermined
distance apart from each other in a face-to-face relation; a first
mirror support member and a second mirror support member supporting
the first mirror and the second mirror, respectively; a plurality
of main rods connecting the first mirror support member and the
second mirror support member with each other; a plurality of
auxiliary rods joined at one ends thereof to the first mirror
support member or the second mirror support member and at the other
ends thereof to a single connection point; a plurality of support
legs for indirectly supporting the first and second mirrors at a
total of three points including two points on the first mirror
support member and the single connection point at which the
auxiliary rods are joined together; and a base on which the support
legs are fixedly mounted; wherein the support legs are composed of
follower members capable of following an expansion or contraction
of the base.
[0014] The above and other objects, features and advantages of the
present invention will become more readily apparent from the
following detailed description of preferred embodiments of the
present invention taken in conjunction with the accompanying
drawings.
DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view illustrating a mirror support
structure according to a first embodiment of the present
invention.
[0016] FIG. 2 is a perspective view illustrating a mirror support
structure according to a second embodiment of the present
invention.
[0017] FIG. 3 is a perspective view illustrating a mirror support
structure according to a third embodiment of the present
invention.
[0018] FIG. 4 is a perspective view illustrating a mirror support
structure according to a fourth embodiment of the present
invention.
[0019] FIG. 5 is a perspective view illustrating a mirror support
structure according to a fifth embodiment of the present
invention.
[0020] FIG. 6 is a perspective view illustrating an example of a
known mirror support structure.
[0021] FIG. 7 is a perspective view illustrating another example of
a known mirror support structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Now, preferred embodiments of the present invention will be
described in detail while referring to the accompanying drawings.
In the following description and the accompanying drawings, like or
corresponding parts are identified by the same or like symbols.
[0023] Embodiment 1.
[0024] FIG. 1 illustrates, in a perspective view, a mirror support
structure according to a first embodiment of the present invention.
In this figure, the mirror support structure of this embodiment
includes a first mirror in the form of a main mirror 1, a second
mirror in the form of an auxiliary mirror 2 arranged in an optimal
relative positional relation with respect to the main mirror 1, a
first support member in the form form of a main mirror support
member 3 of a triangular shape to which the main mirror 1 is
fixedly secured, and a second support member in the form of an
auxiliary mirror support member 4 of a triangular shape to which
the auxiliary mirror 2 is fixedly secured.
[0025] A plurality of (e.g., three in the illustrated example) main
rods 15a are secured at one ends thereof to the three apexes of the
main mirror support member 3, respectively, and at the other ends
thereof to the three apexes of the auxiliary mirror support member
4, respectively, for connecting the main and auxiliary mirror
support members 3, 4 with each other. Also, a plurality of (e.g.,
three in the illustrated example) auxiliary rods 15b are connected
at one ends thereof with three apexes of the auxiliary mirror
support member 4, respectively, and at the other ends thereof with
a single connection point A to be described later. The
corresponding main and auxiliary rods 15a, 15b are formed into
continuous and integral rectilinear configurations. A plurality of
(e.g., three in the illustrated example) support legs 26, which act
as follower members and are each composed of a triangular-shaped
plate spring, serve to support, at their upper apex, two points or
apexes B of the main mirror support member 3 and the connection
point A at which the other ends of the auxiliary rods 15b are
joined together. The triangular-shaped support legs 26 are fixedly
secured at their base side to a base panel 7.
[0026] In this first embodiment, the corresponding main and
auxiliary rods 15a, 15b are in the shape of continuously extending
rectilinear configurations, and the one ends of the main rods 15a
are joined to the three apexes of the triangular-shaped main mirror
support member 3, respectively, whereas the other ends of the
auxiliary rods 15b are joined together at the connection point A.
Thus, three pairs of mutually connected main and auxiliary rods
15a, 15b cooperate to form a trussed structure including the three
sides of the main mirror support member 3.
[0027] Moreover, the three support legs 26 individually joined to
the two apexes B of the main mirror support member 3 and the
connection point A are each formed of a triangular plate spring
which has high rigidity and high strength against an in-plane
external force acting on each support leg 26 in a direction
parallel to the surface thereof, and which has a certain degree of
elasticity acting in an out-of-plane direction (i.e., in a
direction perpendicular to the surface of each plate spring). The
three support legs 26 are arranged in such a manner that they have
elasticity in directions different from each other.
[0028] With such a mirror support structure as described above, the
main rods 15a, the auxiliary rods 15b, the three sides of the main
mirror support member 3 and the three sides of the auxiliary mirror
support member 4 together constitute a trussed structure, thus
providing a light-weight and highly rigid mirror support structure.
Moreover, since the main mirror 1 and the auxiliary mirror 2 are
supported on the base panel 7 by means of the three support legs 26
alone, even if the base panel 7 is distorted or deformed in a
direction perpendicular to the surface thereof, there will be no or
little moment load transmitted to the main mirror support member 3
and the auxiliary mirror support member 4.
[0029] In addition, even with an expansion or contraction of the
base panel 7 among the three support legs 26, the support legs 26
composed of plate springs can follow the expansion or contraction
of the base panel 7 whereby resultant expansion or contraction load
will be prevented from being transmitted from the base panel 7 to
the main rods 15a and the auxiliary rods 15b. As a consequence,
even in the event there is an environmental variation in the
installation place or deformation in the mounting surface for the
mirror support structure, the relation between the relative
positions of the main mirror 1 and the auxiliary mirror 2 is
maintained properly to avoid the deformation of the main mirror 1
and the auxiliary mirror 2.
[0030] Some examples of using the mirror support structure of this
first embodiment are an optical mirror in an optical sensor, a
reflector in a radio wave sensor, an optical antenna in optical
communications equipment, and an antenna in radio communications
equipment.
[0031] In the case of the main and auxiliary mirrors 1, 2 being
used as an optical sensor, unillustrated aligned holes are formed
through the main mirror 1 and the auxiliary mirror 2 in their
centers, and a light detector or a wave detector for sensing
observation light or a signal is mounted on the back side of the
main mirror support member 3 opposite the front side thereof at
which the main mirror 1 is supported, so that the observation light
or signal received is reflected by the main mirror 1 and the
auxiliary mirror 2 to be introduced into the detector through the
holes in the main mirror 1 and the main mirror support member
3.
[0032] On the other hand, when the main and auxiliary mirrors 1, 2
act as a communication instrument for the transmission of a signal,
a transmitter is mounted on the back side of the main mirror
support member 3 for transmitting a sending signal through aligned
holes (not shown) formed through the main mirror support member 3
and the main mirror 1 so that the signal is reflected by the
auxiliary mirror 2 to be further reflected by and projected from
the main mirror 1.
[0033] Here, it is needless to say that a reflection mirror, a
relay optical system and so on may be provided on the back side of
the main mirror support member 3.
[0034] Embodiment 2.
[0035] FIG. 2 illustrates, in a perspective view, a mirror support
structure according to a second embodiment of the present
invention. In the following description of further embodiments of
the present invention, the same symbols as those used in the first
embodiment are attached to the same or corresponding parts of these
embodiments.
[0036] In the second embodiment, in addition to the three main rods
15a and the three auxiliary rods 15b employed in the first
embodiment, the three apexes of the triangular-shaped main mirror
support member 3 and non-corresponding or different three apexes of
the triangular-shaped auxiliary mirror support member 4 which are
not connected with each other by means of the main rods 15a are
also connected with each other through additional three main rods
25a.
[0037] Owing to such a construction, a total of six sides of the
main mirror support member 3 and the auxiliary mirror support
member 4 plus six rods 15a, 15b and 25a cooperate with each other
to construct a trussed structure comprising a total of twelve
structural elements.
[0038] Also, three support legs 26 of this embodiment individually
joined to the connection point A and two apexes B of the main
mirror support member 3 are similar to the support legs 26 of the
first embodiment 1. That is, the support legs 26 of this second
embodiment are each composed of a triangular-shaped plate spring
that has high rigidity and high strength against an in-plane
external force acting thereon in a direction parallel to the
surface thereof and a certain degree of elasticity in an
out-of-plane direction, i.e., in a direction perpendicular to the
surface thereof. The three support legs 26 are arranged in such a
manner that they have elasticity in different directions,
respectively.
[0039] The second embodiment can provide the same effects or
advantages as in the first embodiment, and in addition to these,
three apexes of the main mirror support member 3 and three apexes
of the auxiliary mirror support member 4 are connected with each
other by means of the three additional main rods 25a, whereby the
rigidity in the arrangement of the main mirror support member 3 and
the auxiliary mirror support member 4 is further enhanced. As a
result, in case where the mirror support structure of this
embodiment is installed on a moving object in the form of a
satellite, vibration resistance against the vibration load applied
to the mirror support structure upon launching can be improved to a
substantial extent.
[0040] Embodiment 3.
[0041] FIG. 3 illustrates, in a perspective view, a mirror support
structure according to a third embodiment of the present invention.
In this embodiment 3, three apexes of the main mirror support
member 3 and three apexes of the auxiliary mirror support member 4
are connected with each other by means of a total of six main rods
35a. Also, a plurality of auxiliary rods 35b are joined at one ends
thereof to three apexes of the triangular-shaped auxiliary mirror
support member 4, respectively, and at the other ends thereof to
the single connection point A.
[0042] According to this construction, a total of six sides of the
support members 3, 4, six main rods 35a and three auxiliary rods
35b are combined with each other to form a trussed structure
comprising a total of fifteen structural elements.
[0043] Moreover, the three support legs 26 of this third embodiment
individually joined to the connection point A and the two apexes B
of the main mirror support member 3 are of the same construction as
the support legs 26 of the first embodiment.
[0044] According to the third embodiment, there can be obtained the
same effects or advantages as those in the first embodiment 1, and
in addition to these, the three apexes of the main mirror support
member 3 and the three apexes of the auxiliary mirror support
member 4 are respectively connected with each other by means of the
six main rods 35a, so that the rigidity in the arrangement of the
main mirror support member 3 and the auxiliary mirror support
member 4 are further improved in comparison with the mirror support
structure of the first embodiment, thus enhancing the vibration
resistance as well.
[0045] In addition, even if the length of each auxiliary rod 35b is
shortened, there can be ensured the same degree of rigidity as in
the first embodiment, as a consequence of which the axial size or
distance between the main mirror 1 and the auxiliary mirror 2 of
the mirror support structure can be reduced.
[0046] Embodiment 4.
[0047] FIG. 4 illustrates, in a perspective view, a mirror support
structure according to a fourth embodiment of the present
invention. In this embodiment, the triangular-shaped main mirror
support member 3 and the triangula-shaped auxiliary mirror support
member 4 each have one side of a triangle arranged in parallel to
the base panel 7. Three apexes of the main mirror support member 3
and three apexes of the auxiliary mirror support member 4 are
connected with each other by means of a total of six main rods 45a.
In addition, the three apexes of the main mirror support member 3
are joined to one ends of the auxiliary rods 45b, respectively, of
which the other ends are joined to the connection point A disposed
apart from the main mirror 1 on one side thereof opposite the
auxiliary mirror 2. Thus, a total of six sides of the support
members 3, 4 and nine main and auxiliary rods 45a, 45b cooperate
with each other to construct a trussed structure comprising a total
of fifteen structural elements.
[0048] Moreover, three support legs 26, 36 are individually joined
at their top ends or apexes to the connection point A and two
apexes B of the main mirror support member 3. Among these support
legs 26, 36, one support leg 36 arranged at the connection point A
is composed of two triangular-shaped plate springs which are
crossed with each other so as provide high rigidity in all
directions, and the other support legs 26 are each composed of a
single plate spring, and are arranged to have a certain degree of
elasticity in a direction toward the connection point A of the
three rods 45b with their normal lines disposed perpendicular to
each other.
[0049] The fourth embodiment can achieve the same effects or
advantages as in the third embodiment. Additionally, in comparison
with the third embodiment, the main mirror support member 3 is
supported by the main rods 45a and the auxiliary rods 45b in
combination, so that it is further prevented from deformation
against the load acting thereon, thereby improving the vibration
resistance.
[0050] Moreover, since the auxiliary mirror support member 4 is
supported by the main mirror support member 3 through the main rods
45a, but not directly supported on the base panel 7, there is no
fear that the expansion or contraction of the base panel 7 would
result in a variation in the distance between the auxiliary mirror
support member 4 and the main mirror support member 3.
[0051] Embodiment 5.
[0052] FIG. 5 illustrates, in a perspective view, a mirror support
structure according to a fifth embodiment of the present invention,
in which the triangular-shaped main mirror support member 3 and the
triangular-shaped auxiliary mirror support member 4 are arranged in
such a manner that they have one side of a triangle disposed
perpendicular to the surface of the base panel 7. The three apexes
of the main mirror support member 3 and the three apexes of the
auxiliary mirror support member 4 are connected with each other by
means of a total of six main rods 55a. Also, the three apexes of
the main mirror support member 3 are joined to one ends of the
auxiliary rods 55b, respectively, of which the other ends thereof
are joined to the connection point A that is disposed apart from
the main mirror 1 on one side thereof opposite the auxiliary mirror
2. Thus, a total of six sides of the support members 3, 4 and nine
rods 55a, 55b cooperate with each other to provide a trussed
structure comprising a total of fifteen structural elements.
[0053] In addition, three support legs 26, 36 are individually
joined to the connection point A and two apexes B of the main
mirror support member 3. Among these support legs 26, 36, the
support leg 36 having high rigidity in all directions is arranged
at and secured to one apex B of the main mirror support member
3.
[0054] The fifth embodiment can achieve the same effects or
advantages as in the fourth embodiment. Additionally, the
connection point A is arranged at a location offset from the center
of the main mirror support member 3 (i.e., near the support leg 36
and away from the other support leg 26), so that a large free space
can be provided at the side of the main mirror support member 3
opposite the main mirror 1 in comparison with the fourth
embodiment, accordingly making it easy to mount peripheral
equipment such as a light detector, a wave detector, optical relay
components, etc.
[0055] Here, note that the triangular-shaped main mirror support
member 3 may be arranged with one side thereof not perpendicular
but inclined with respect to the surface of the base panel 7.
[0056] Although in the above-mentioned respective embodiments, the
support legs 26 are composed of plate springs, it goes without
saying that the support legs are not limited to such, but instead
may comprise any form of follower members capable of following the
expansion or contraction of the base panel 7, and hence they may
be, for example, a mechanism called "a kinematic mount" using
bearings with a certain degree of freedom of movement or rotation.
Also, such a mechanism may be combined with a plate spring. In
addition, it is needless to say that the shape of the main mirror
support member and the auxiliary mirror support member is not
limited to the triangle, but may be any other shape. Besides, the
trussed structure constructed by using the main rods and the
auxiliary rods is not limited to those which are shown in the
above-mentioned first through fifth embodiments.
[0057] As described above, a mirror support structure according to
the present invention comprises: a first mirror and a second mirror
disposed a predetermined distance apart from each other in a
face-to-face relation; a first mirror support member and a second
mirror support member supporting the first mirror and the second
mirror, respectively; a plurality of main rods connecting the first
mirror support member and the second mirror support member with
each other; a plurality of auxiliary rods joined at one ends
thereof to the first mirror support member or the second mirror
support member and at the other ends thereof to a single connection
point; a plurality of support legs for indirectly supporting the
first and second mirrors at a total of three points including two
points on the first mirror support member and the single connection
point at which the auxiliary rods are joined together; and a base
on which the support legs are fixedly mounted. The support legs are
composed of follower members capable of following an expansion or
contraction of the base. With this arrangement, it is possible to
provide the mirror support structure which is light in weight and
high in rigidity.
[0058] In addition, since the first mirror and the second mirror
are supported on the base only by the three support legs, even if
there takes place a distortion or an out-of-surface deformation of
the base (i.e., deformation in a direction perpendicular to a
surface of the base), a moment load generated on the base is not
transmitted to the first and second mirrors. Also, even if there
occurs an expansion or contraction of that portion of the base
which lies within a triangular area defined by the three support
legs, the support legs can follow such an expansion or contraction
of the base so that a load causing the rods to expand or contract
is not transmitted from the base to the rods via the supports legs.
As a result, even in the event that there occurs an environmental
variation in the place of installation or deformation of a mounting
surface, the relative positional relation between the first mirror
and the second mirror is maintained properly, thereby preventing
any serious deformation of the first and second mirrors which would
otherwise adversely affect the performance thereof.
[0059] According to a preferred form of the present invention, the
first mirror support member and the second mirror support member
are each composed of a triangular-shaped panel, and the main rods
and the auxiliary rods comprise three pairs of main and auxiliary
rods joined together in each pair to form a continuous and integral
rectilinear configuration. The three pairs of continuously and
integrally joined main and auxiliary rods serve to connect three
apexes of the first triangular-shaped mirror support member with
three corresponding apexes of the second triangular-shaped mirror
support member, respectively, to cooperate with three sides of the
first triangular-shaped mirror support member and three sides of
the second triangular-shaped mirror support member to form a
trussed structure. Thus, the main rods, auxiliary rods, the three
sides of the first mirror support member and the three sides of the
second mirror support member cooperate with other to form a trussed
structure, thus providing a light-weight and highly rigid mirror
support structure.
[0060] According to another preferred form of the present
invention, the main rods comprise additional main rods connecting
three apexes of the first triangular-shaped mirror support member
with three different apexes of the second triangular-shaped mirror
support member in combinations different from those in which the
three apexes of the first triangular-shaped mirror support member
and the three corresponding apexes of the second triangular-shaped
mirror support member are connected with each other by means of the
three pairs of continuous and integrally joined main and auxiliary
rods. Accordingly, the rigidity in an assembly or arrangement of
the first mirror support member and the second mirror support
member is further improved. For example, in case the mirror support
structure is installed on a moving object in the form of a
satellite, it is possible to enhance the vibration resistance of
the mirror support structure to a vibration load applied thereto
upon launching of the satellite.
[0061] According to a further preferred form of the present
invention, the first mirror support member and the second mirror
support member are each composed of a triangular-shaped panel, and
the main rods comprise six main rods connecting three apexes of the
first mirror support member and three apexes of the second mirror
support member, respectively. The auxiliary rods comprise three
auxiliary rods joined to three apexes of the second mirror support
member, respectively, the six main rods and the three auxiliary
rods cooperating with three sides of the first triangular-shaped
mirror support member and three sides of the second
triangular-shaped mirror support member to form a trussed
structure. Thus, an assembly or arrangement of the first mirror
support member and the second mirror support member becomes high in
rigidity and vibration resistance.
[0062] In addition, the lengths of the auxiliary rods can be
shortened to accordingly make the entire mirror support structure
compact while ensuring the rigidity of the second mirror support
member.
[0063] According to a still further preferred form of the present
invention, the first mirror support member and the second mirror
support member are each composed of a triangular-shaped panel, and
the first triangular-shaped mirror support member and the second
triangular-shaped mirror support member are arranged such that they
have one side disposed in parallel with a surface of the base. The
main rods comprise six main rods connecting three apexes of the
first triangular-shaped mirror support member and three apexes of
the second triangular-shaped mirror support member with each other.
The auxiliary rods comprise three auxiliary rods joined to the
three apexes of the first triangular-shaped mirror support member,
respectively, the six main rods and the three auxiliary rods
cooperating with three sides of the first triangular-shaped mirror
support member and three sides of the second triangular-shaped
mirror support member to form a trussed structure. Thus, the first
mirror support member is supported by the main rods and the
auxiliary rods so that it is further prevented from deformation
against a load applied thereto and becomes high in vibration
resistance.
[0064] Moreover, since the second mirror support member is
supported on the base not directly but through the first mirror
support member, there will be no variation in the distance between
the first and second mirror support members resulting from an
expansion or contraction of the base.
[0065] According to a yet further preferred form of the present
invention, the first mirror support member and the second mirror
support member are each composed of a triangular-shaped panel, and
the first triangular-shaped mirror support member and the second
triangular-shaped mirror support member are arranged such that they
have each side disposed in antiparallel with a surface of the base.
The main rods comprise six main rods connecting three apexes of the
first triangular-shaped mirror support member and three apexes of
the second triangular-shaped mirror support member with each other.
The auxiliary rods comprise three auxiliary rods joined to three
apexes of the first triangular-shaped mirror support member,
respectively, the six main rods and the three auxiliary rods
cooperating with three sides of the first triangular-shaped mirror
support member and three seides of the second triangular-shaped
mirror support member to form a trussed structure. Accordingly, as
referred to above, the first mirror support member, being supported
by the main rods and the auxiliary rods, is further prevented from
deformation against a load applied thereto and hence becomes high
in vibration resistance. In addition, the second mirror support
member is supported on the base not directly but through the first
mirror support member, so that there will be no variation in the
distance between the first and second mirror support members
resulting from an expansion or contraction of the base.
[0066] According to a further preferred form of the present
invention, the follower members are each composed of a plate
spring, so that they can follow the expansion or contraction of the
base with such a simple construction.
* * * * *