Note: Descriptions are shown in the official language in which they were submitted.
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COMPACT MECHANISM FOR THE INTER-PUPIL DISTANCE ADJUSTMENT
OF VIEWING SYSTEMS
CROSS-REFERENCE TO RELATED APPLICATIONS
This Application claims rights under 35 USC 119(e) from U.S. Application
Serial No. 62/046,195 filed September 5, 2014, the contents of which are
incorporated
herein by reference. This application is related to provisional application
Serial No.
61/674,432 filed July 23, 2012.
STATEMENT OF GOVERNMENT INTEREST
This invention was made with United States Government support under
Contract No. H94003-04-D-0002/0076 awarded by the United States Department of
the Air Force. The United States Government has certain rights in this
invention.
FIELD OF THE INVENTION
This invention relates to the adjustment of inter-pupil distance in a pair of
binoculars, and more particularly to this adjustment when the binoculars
include a
rectilinear focal plane array.
BACKGROUND OF THE INVENTION
As will be appreciated, in order to accommodate different individuals, the
inter-ocular distance or inter-pupil distance (IPD) is normally adjusted in a
hinged
arrangement in which the two optical telescopes of the binocular are pivoted
about the
hinge by flattening or sharpening the angle subtended by the hinge arms to the
binocular telescopes. While this type of adjustment to accommodate different
individuals is commonplace, when binoculars are used in a system in which
scenes
are imaged onto the human eye, since the eyes are orientation independent, no
distortions occur. However, when, for instance, focal plane arrays are used as
detectors in the infrared imaging systems, swinging apart the hinged optical
telescopes correspondingly affects the rectilinear focal plane arrays at each
of the
telescopes such that the original horizontal orientations of the focal plane
arrays are
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skewed off axis with respect to one to the other during this type of
adjustment. When
these focal plane arrays are used to generate images, if their horizontal
edges are not
along a single horizontal line, there is considerable distortion, which can
make focal
plane arrays unusable.
It will be appreciated that the optics utilized in binoculars have spherical
lens
systems, and with visible light, the eye does not recognize orientation of the
lens. The
eye, for instance, does not know the angle that the image is coming in on, and
therefore, at least for the visible region of the electromagnetic spectrum,
the eye is
orientation independent.
On the other hand, since the eye cannot detect infrared radiation, infrared
detecting systems require detector arrays such as focal plane arrays, for
instance,
available in CCD cameras. These focal plane arrays are rectilinear, with each
focal
plane array positioned at the focal plane of the corresponding telescopic
element.
When the infrared binoculars are appropriately adjusted for an individual, it
is
important that the orientation of the focal plane arrays in each of the
telescopic
elements is such that the horizontal portion of the focal plane array in one
eyepiece is
along the same horizontal line as the horizontal portion of the focal plane
array in the
other telescopic element.
If inter-ocular distance were to be adjusted by the traditional pivot method,
maintenance of this horizontal focal plane array orientation would be skewed
such
that for any binocular system, there would be a large distortion of the image.
Moreover, when the human eyes view the images from the focal plane arrays,
they
cannot mentally accommodate for the misalignment.
Thus, a heretofore unaddressed need exists in the industry to address the
aforementioned deficiencies and inadequacies.
SUMMARY OF THE INVENTION
Embodiments of the present disclosure provide a system and method for
adjusting an inter-pupil distance between eyepieces. Briefly described, in
architecture, one embodiment of the system, among others, can be implemented
as
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follows. An apparatus is provided for adjusting an inter-pupil distance
between
eyepieces associated with a pair of telescopic elements in a viewing system
with each
of the telescopic elements having a corresponding rectilinear focal plane
array at the
focal plane thereof. The apparatus includes a mechanical drive for moving the
focal
plane arrays associated with the telescopic elements, wherein the inter-pupil
distance
is adjusted without skewing an orientation of the focal plane arrays, wherein
distortion associated with inter-pupil distance adjustment is eliminated.
The present disclosure can also be viewed as providing methods of adjusting
an inter-pupil distance of eyepieces associated with a pair of telescopic
elements in a
viewing system, wherein the pair of telescopic elements is associated
rectilinear focal
plane arrays for each of the eyepieces. In this regard, one embodiment of such
a
method, among others, can be broadly summarized by the following steps:
mounting
the pair of telescopic elements and the associated rectilinear focal plane
arrays
whereby the focal plane arrays are constrained in horizontal translation, and
whereby
the focal plane arrays have co-located center lines; and translating the pair
of
telescopic elements to adjust the inter-pupil distance of the eyepieces
without skewing
the rectilinear focal plane arrays during translation, whereby distortion
associated
with any skewing of the rectilinear focal plane arrays during inter-pupil
distance
adjustment is minimized.
The present disclosure can also be viewed as providing an apparatus for
adjusting inter-pupil distance of viewing systems. Briefly described, in
architecture,
one embodiment of the apparatus, among others, can be implemented as follows.
A
viewing system has a pair of eyepieces, wherein the pair of eyepieces is
associated
with a pair of telescopic elements. A corresponding rectilinear focal plane
array is
positioned at a focal plane of each of the pair of telescopic elements. A
mechanical
drive system is coupled to the pair of telescopic elements, wherein actuation
of the
mechanical drive system moves the focal plane arrays associated with the pair
of
telescopic elements, wherein the inter-pupil distance is adjusted without
skewing an
orientation of the focal plane arrays.
Other systems, methods, features, and advantages of the present disclosure
will be or become apparent to one with skill in the art upon examination of
the
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following drawings and detailed description. It is intended that all such
additional
systems, methods, features, and advantages be included within this
description, be
within the scope of the present disclosure, and be protected by the
accompanying
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the disclosure can be better understood with reference to the
following drawings. The components in the drawings are not necessarily to
scale,
emphasis instead being placed upon clearly illustrating the principles of the
present
disclosure. Moreover, in the drawings, like reference numerals designate
corresponding parts throughout the several views.
FIG. 1 is a diagrammatic illustration of a pair of binoculars having a hinged
adjustment arrangement for pivoting the two telescopic elements closer or
farther
away from each other so as to adjust the inter-pupil distance of the
associated
eyepieces, in accordance with the prior art;
FIGS. 2A and 2B are diagrammatic illustrations of the telescopic elements of
the binoculars of FIG. 1 showing the orientation of the corresponding focal
plane
arrays co-located along a single horizontal line and skewed when the
telescopic
elements are hingedly moved to adjust inter-pupil distance, in accordance with
the
prior art;
FIG. 3 is a diagrammatic illustration of a pair of binoculars having a lever
adjustment for the inter-pupil distance of the associated eyepieces, in
accordance with
a first exemplary embodiment of the present disclosure;
FIG. 4 is a diagrammatic illustration of the mounting of the eyepieces of the
telescopic elements of the binoculars in FIG. 3 illustrating the horizontal
movement of
carriages containing these telescopic elements coupled to a rack and pinion
arrangement, with the rotation of the pinion moving the eyepieces of the
telescopic
elements closer together or further apart from each other constrained to a
single
horizontal direction, thus to maintain the corresponding focal plane arrays to
movement in this horizontal direction, in accordance with the first exemplary
embodiment of the present disclosure;
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FIG. 5 is a cross-sectional diagram of the rack and pinion arrangement of FIG.
4 showing the lever attached to a shaft mounted for rotation in the binocular
housing,
with the shaft coupled to a pinion gear, in accordance with the first
exemplary
embodiment of the present disclosure; and,
FIGS. 6A, 6B and 6C are top views of the rack and pinion arrangement of
FIG. 4 showing that, with the rotation of the pinion gear, the inter-pupil
distance of
the eyepieces associated with the telescopic elements is increased with a
clockwise
rotation of the pinion gear and decreased with counter clockwise pinion gear
rotation,
in accordance with the first exemplary embodiment of the present disclosure.
DETAILED DESCRIPTION
In order to achieve horizontal inter-pupil distance adjustment, in the subject
invention, each of the binocular telescopic elements is mounted for horizontal
translation on a carriage, with the adjustment being provided by a rack and
pinion
arrangement actuated by a lever on the top of the binoculars. The lever is
mechanically coupled to a pinion gear such that with rotation of the gear, the
associated racks move in opposite directions. Each of these racks is
mechanically
coupled to a horizontally translatable carriage so as to move the telescopic
elements
closer to each other or further from each other, constrained to horizontal
movement.
Since each of the telescopic elements carries its own focal plane array, and
since the focal plane array has a horizontal edge parallel to the direction of
moment of
its carriage, adjustment of the inter-pupil or inter-ocular distance does not
require
skewing or canting of the focal plane arrays. The result is that inter-ocular
distance
can be adjusted without distortion. While the subject invention will be
described in
terms of its use in infrared binoculars, the subject invention relates to any
type of
binocular which utilizes rectilinear focal plane arrays. Thus, the subject
invention provides for a compact mechanism of IPD adjustment in viewing
systems.
The present invention in one embodiment is an apparatus for adjusting the IPD
of
viewing systems comprised of a housing unit containing a pair of telescopic
components, a switch lever, a shaft coupled to the shift lever, a gear secured
to the
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shaft, and pupil distance lever racks actuated by the gear and coupled to
respective
telescopic components.
Referring now to the figures, FIG. 1 is a diagrammatic illustration of a pair
of
binoculars having a hinged adjustment arrangement for pivoting the two
telescopic
elements closer or farther away from each other so as to adjust the inter-
pupil distance
of the associated eyepieces, in accordance with the prior art. As shown, a
conventional pair of binoculars 10 have a central pivot 12 and a pair of pivot
arms 14,
16 by which telescopic elements 18, 20 can be pivoted either closer together
or farther
away from each other. The resulting motion correspondingly moves eyepieces 22,
24
either closer together or farther away from each other.
FIGS. 2A and 2B are prior art diagrammatic illustrations of the telescopic
elements of the binoculars of Figure 1 showing the orientation of the
corresponding
focal plane arrays co-located along a single horizontal line and skewed when
the
telescopic elements are hingedly moved to adjust inter-pupil distance, in
accordance
with the prior art. In FIG. 2A, the binoculars 10 have corresponding
rectilinear focal
point arrays 26, 28, each having a vertical centerline 30 spaced from a
centerline 32
corresponding to the centerline of the binoculars 10. Here, the focal plane
arrays 26,
28 are illustrated by dotted boxes 31. The distance between the centerlines
30, 32
refers to one-half the inter-pupil distance. When it is desired to increase
the inter-pupil
distance, as illustrated in FIG. 2B, arms 14, 16 are moved apart so as to
flatten the
angle subtended by center pivot 12 and increase the distance between
centerlines 30,
32, thereby to increase the inter-pupil distance.
However, as can be seen, the original horizontal centerlines 40 of the focal
plane arrays 31 which lie along horizontal line 42, are now skewed, as
illustrated at
40' in FIG 2B. Thus, lines 40' are not only not parallel to each other, but
they also are
not horizontal. The result is that images collected on focal plane arrays 31
will be
distorted and unusable once the original horizontal parallel orientations are
disturbed
through the adjustment of the binoculars of FIG. 1.
FIG. 3 is a diagrammatic illustration of a pair of binoculars having a lever
adjustment for the inter-pupil distance of the associated eyepieces, in
accordance with
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a first exemplary embodiment of the present disclosure. In one embodiment of
the
present disclosure, a pair of binoculars 50 is provided with an inter-pupil
distance
control lever 52 which controls the distance of eyepieces 54, 56 associated
with
telescopic elements 58, 60. It is a purpose of this control lever and
adjustment system
to maintain the parallel orientation of the focal plane arrays associated with
telescopic
elements 58, 60 during adjustment. In one embodiment, the IPD adjustability
may
range from 2.17 inches to 2.84 inches to precisely adjust to the IPD for the
middle
90% of the male population.
FIG. 4 is a diagrammatic illustration of the mounting of the eyepieces of the
telescopic elements of the binoculars in FIG. 3 illustrating the horizontal
movement of
carriages containing these telescopic elements coupled to a rack and pinion
arrangement, with the rotation of the pinion moving the eyepieces of the
telescopic
elements closer together or farther apart from each other constrained to a
single
horizontal direction, thus to maintain the corresponding focal plane arrays to
movement in this horizontal direction, in accordance with the first exemplary
embodiment of the present disclosure. The focal plane arrays 62, 64 are shown
in
dotted outline within carriages 66, 68 on to which are mounted corresponding
eyepieces 54, 56. Here, it will be seen that carriages 66, 68 are coupled to
racks 70, 72
that cooperate with a pinion gear 74 to move carriages 66, 68 and
corresponding
eyepieces 54, 56 either closer together or farther apart. Each of the
carriages 66, 68
has pins 76 which project through respective slots 78, 80, 82 and 84 to limit
the
motion of the carriages, and thus the corresponding eyepieces 54, 56 and focal
point
arrays 62, 64.
FIG. 5 is a cross-sectional diagram of the rack and pinion arrangement of FIG.
4 showing the lever attached to a shaft mounted for rotation in the binocular
housing,
with the shaft coupled to a pinion gear, in accordance with the first
exemplary
embodiment of the present disclosure. As is shown in FIG. 5, lever 52 may be
connected to a shaft 90 mounted for rotation to chassis 92, with pinion 74
coupled to
shaft 90. Accordingly, actuation of the lever 52 may rotate the shaft 90,
which in turn,
causes movement of the pinion gear 74, which can then move the racks 70, 72
(FIG.
4).
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FIGS. 6A, 6B and 6C are top views of the rack and pinion arrangement of
FIG. 4 showing that, with the rotation of the pinion gear, the inter-pupil
distance of
the eyepieces associated with the telescopic elements is increased with a
clockwise
rotation of the pinion gear and decreased with counter clockwise pinion gear
rotation,
in accordance with the first exemplary embodiment of the present disclosure.
As
shown in FIGS. 6A, 6B, and 6C, the pinion gear 74 and racks 70, 72 can be used
to
move eyepieces 54, 56 between various positions. In FIG. 6A, the eyepieces 54,
56
are spaced apart by inter-pupil distance 96. When pinion gear 74 is rotated
clockwise,
as indicated by arrow 98, racks 70, 72 move apart, thereby increasing to inter-
pupil
distance 96', as illustrated. Moreover, as illustrated in FIG. 6C, when pinion
gear 74
is rotated counterclockwise, as indicated by arrow 100, racks 70, 72 move to
decrease
the inter-pupil distance 96".
Thus, in one exemplary embodiment, the apparatus may include five main
components: the upper housing, the switch lever, the shaft, the gear, and the
two
racks. The housing unit may be the casing of the device. With respect to FIGS.
2-6C,
the switch lever 52 may be operated by the user when adjustment of the IPD is
desired. The shaft 90 may be rigidly connected to switch lever 52. Therefore,
when
the user operates the switch lever 52, the shaft 90 necessarily rotates. The
pinion gear
74 is rigidly connected to the shaft. As such, it rotates when the shaft 90
rotates,
which rotates as the switch lever 52 rotates. The two racks 70, 72 operate as
one unit
adjusting the two different eyepieces 54, 56. These racks 70, 72 are driven by
the
pinion gear 74. As such, when the pinion gear 74 rotates, the racks70, 72
translate the
rotational movement to linear movement. The racks 70, 72 are connected at
opposite
sides of the pinion gear 74 such that the racks 70, 72 move in opposite
directions as
the pinion gear 74 rotates.
It is noted that the subject arrangement moves the associated focal plane
arrays
such that their orientation is always parallel one to the other regardless of
the inter-
ocular adjustment. Moreover, while a rack and pinion arrangement has been
discussed, other mechanical or electromechanical linkages which move the
telescopic
elements and associated eyepieces such that the associated focal plane arrays
are
parallel are within the subject matter of this invention. Further, it is
possible to move
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only one of the telescopic elements and associated eyepiece with respect to a
fixed
telescopic element and eyepiece such that the associated focal plane arrays
maintain
their parallel orientation during the inter-ocular adjustment.
It is further noted that the present invention does not require vertical
movement of the eyepieces because the viewing area inside the device is
axisymmetric and there is no electronic display. Unlike other systems, this
invention
does not rotate or distort the imagery because it remains parallel.
Furthermore, it
provides smooth operation throughout its range. As such, although the
preferred
embodiment of the present invention was designed to meet the needs of thermal
infrared (IR) imaging, it is applicable to other viewing systems.
While the present invention has been described in connection with the
preferred embodiments of the various figures, it is to be understood that
other similar
embodiments may be used or modifications or additions may be made to the
described embodiment for performing the same function of the present invention
without deviating therefrom. Therefore, the present invention should not be
limited to
any single embodiment, but rather construed in breadth and scope in accordance
with
the recitation of the appended claims.
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