Prismatic optical viewing glasses

Optical viewing glasses incorporate a visor positioned at the brow line or a wearer above the normal viewing field from which a pair of prisms depend without additional supporting structure thereby allowing the wearer to have a redirected field of vision while retaining peripheral viewing fields.

FIELD OF THE INVENTION
 The present invention relates to optical devices, and, in particular to a
 viewing glasses incorporating optical prisms for redirecting a forward
 field of view.
 BACKGROUND OF THE INVENTION
 Optical devices for redirecting fields of view have been proposed for
 varying applications thereby enabling a wearer to access a viewing
 panorama offset from the normal line of sight. With such approaches, the
 wearer is able to secure desired views without changing body and head
 positions and/or by superimposing backgrounds for facilitating or
 ameliorating certain conditions.
 In U.S. Pat. No. 5,042,910 to Dolezal a removable elongated plastic prism
 is interfaced with a slotted shield for redirecting the field of vision of
 the wearer. The shield and associated frame are intended for blocking all
 images not passing through the prismatic lenses. A tunnel vision is
 effected and peripheral viewing areas are blocked.
 U.S. Pat. No. 4,804,261 to Kirschen discloses a rearward mirrored viewing
 system for patients prone to claustrophobia. Therein a mirror mounted on
 frames provides a rearwardly directed, background view at the end of a
 magnetic resonance instrument thereby providing an artificial backdrop
 removing the tunnel like aspects and resulting claustrophobia associated
 with the examination.
 U.S. Pat. No. 4,647,165 to Lewis provides an optical viewing system for
 bike riders wherein prisms are attached to clip-on glass frames and pivot
 downward to an operative position engaging the lens when the riders head
 is lowered thereby providing a redirected view forwardly of the bike.
 U.S. Pat. No. 4,792,223 to Axelbaum discloses an optical device
 incorporated into eyewear frames wherein a lower mirrored secondary lens
 supported in front of and inclined with respect to a primary lens is
 effective for providing a secondary field of view that is superimposed on
 a primary field of view.
 U.S. Pat. No. 6,006,367 to Webster discloses swimming goggles incorporating
 a prismed element allowing a wearer through eye redirection to achieve a
 secondary field of vision. The supporting structure effectively removes
 peripheral sectors from the field of view.
 U.S. Pat. No. 5,173,720 to Lee et al. discloses a specialty eyewear device
 including a slotted frame having mirrored surfaces angularly disposed with
 respect thereto. The wearer may view forwardly through the slots for
 normal straight ahead viewing. Alternatively, the wearer may view
 downwardly through the slots to achieve a redirected view as effected by
 the mirrored surfaces.
 U.S. Pat. No. 4,077,703 to Pablo discloses an eyeframe incorporating prisms
 housed in an elongated frame overlying the wears face and disposed in
 front of the view's eyes for redirecting normal line of sight for reading
 or viewing. The apparatus blocks peripheral view and limits viewing to
 prism transmitted images.
 U.S. Pat. No. 2,123,682 to Wingate discloses laterally slidable prisms
 mounted in eyewear frames for redirecting normal vision angles. The frames
 and peripheral shrouds for the prisms surround the prisms thereby
 effectively limiting frontal viewing to the prismed areas and to the
 exclusion of surrounding peripheral information.
 Accordingly, it is an object of the present to provide optical viewing
 glasses incorporating prisms for redirecting a field of view without a
 loss of peripheral vision.
 Another object of the invention is to provide prism viewing glasses for
 independent wearing or for use in conjunction with conventional
 eyeglasses.
 A further objects of the invention is to provide prism viewing glasses
 wherein the prisms are attached to a visor above the normal visual
 vertical cutoff for view disposition without supporting framework in the
 normal field of view.
 Yet another object of the invention is to provide optical viewing glasses
 having a pair of prisms supported outside the normal field of view
 allowing the wearer to achieve a focal redirected field of view without a
 sacrifice in peripheral visual information.
 SUMMARY OF THE INVENTION
 The foregoing objects are accomplished by optical viewing glasses having a
 visor supported on the wearer at the brow line and normal thereto so as
 not to be visible in a normal forwardly directed vision path. A pair of
 triangular optical prisms depend downwardly from the bottom surface of the
 visor in front of the wearer's eyes. The prisms provide an internally
 reflected and refracted path normal to the forward vision allowing the
 wearer to view scenes without head or body reorientation, such as watching
 television from a supine position. Lateral hinged temples are provided
 above the visor so as not to detract from peripheral vision and to enable
 the optical viewing glasses to be worn over conventional glasses. By
 interposing only the prisms in the field of view, to the exclusion of
 support structure, the wear may obtain a desired redirected field of view
 without a loss of visual information on surroundings and conditions in the
 peripheral areas.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
 Referring to the drawings for the purpose of describing the preferred
 embodiment, FIGS. 1 through 3 illustrate prismatic optical glasses 10 worn
 by a user 12 for receiving a redirected line of sight 14 from a normal
 forward and straight ahead viewing path 16. As will become hereinafter
 apparent, such a redirected line of sight allows the user to engage in
 various viewing activities otherwise requiring body or head repositioning.
 Representative activities include viewing television from a supine
 position on a bed, reclining chair or the like, downward directed
 activities such as reading, typing or the like. Concurrently, with the
 features of the present invention, the user is also able to retain sensory
 visual feeling of surroundings through extensive peripheral areas that are
 not obstructed by visually apparent supporting framework.
 Referring additionally to FIGS. 4 and 5, the glasses 10 comprise a frontal,
 horizontal visor 20, a pair of laterally spaced prismatic elements 22, 24
 depending downwardly from the lower surface 26 of the visor 20, a nose
 piece 27 connected to the visor 20 between the prismatic elements, and a
 pair of laterally spaced rearwardly extending temples 28 attached by
 hinges 29 at the rear lateral corners of the visor. As with conventional
 eyewear, the glasses 10 are supported on the user by the temples 28
 engaging the temple and ear areas of the user, and the nose piece 27
 engaging the bridge of the nose of the user.
 The visor 20 is formed of an opaque, rigid plastic material and comprises a
 planar body 30 having upwardly enlarged bosses 32 at the outer rearward
 comers thereof. The top surface 34 is generally planar and merges with the
 adjacent bosses 32. The lower surface 26 includes a planar central section
 38, parallel to the top surface 34, outwardly terminating with upwardly
 flared end sections 40. The rearward end surface 42 of the bosses 32 is
 substantially planar and transverse to the visor 20. A hinge section 43 of
 the hinge 29 is mechanically connected at the end surface 42 of the
 enlarged bosses 32.
 The temples 28 are conventional in eyewear construction and include
 elongate horizontally extending arms 46 terminating with downwardly curved
 ends 47 for engagement with the ear area of the user. The inner frontal
 end of the arm includes a hinge section 48 for the hinge 29. The hinge
 sections are pivotally interconnected by pin 50 for pivotal movement about
 a vertical axis between the illustrated wearing position and a collapsed
 position wherein the temples abut the rear wall of the visor.
 The front wall of the visor 20 comprises a straight center section 60
 outwardly terminating with rounded side wall 62 blending with the bosses
 32 and substantially coextensive with the flared portions 40 of the lower
 surface 26. Such a frontal profile limits distracting peripheral vision
 obstruction by the visor, both laterally and upwardly.
 The rear wall of the visor comprises a recessed center portion registering
 with the nose of the wearer, laterally extending curved sections 72
 conformal with the brow of the wear and terminating at the enlarged bosses
 32.
 The nose piece 27 includes an L-shaped support arms 74 symmetrically
 disposed at the center of the visor adjacent the rear wall. The arms
 terminate with an end loop connected at the lower surface of the visor by
 fasteners 76. A curved, padded cross member 78 interconnects the support
 arms and engages the nose of the user.
 The prisms 22, 24 are symmetrically disposed on the planar center section
 of the lower surface. The elements are formed or optical grade glass or
 plastic and pentahedral in shape as defined by triangular, parallel end
 walls 80, a vertical end wall 82, a horizontal mounting wall 84 and a
 frontal inclined wall 86. The horizontal mounting wall 84 is adhered to
 the lower surface 26 by a suitable adhesive. The prisms are mounted and
 sized such that the eyes of the wearer are centered on the end wall 82 for
 normal straight forward vision. The visor and the temples are positioned
 at the normal vertical cutoff and thus disposed outwardly of the field of
 view. Such disposition also allows the glasses to be conveniently worn
 over conventional glasses. The lower edge of the walls 82 is accordingly
 at the lower portion of the eye thereby providing, with only minor
 downward eye movement, substantial forward and lateral vision exterior of
 the prisms. The width of the wall is substantially the width of the eye
 whereby substantial peripheral vision is afforded in conjunction with
 prismatic viewing. The prisms are spaced sufficiently close together to
 provide continuous binocular viewing without blind spots or other
 discontinuities.
 The prisms function in a well known manner to reflecting and refracting
 images as indicated in FIG. 3. In the present invention, the end walls 80
 are non-reflective and generally translucent. Frosted surfaces are
 preferred inasmuch as secondary images are not transmitted and discernable
 visible information is not presented by the coating. The end wall 82 is a
 clear polished surface and is located in the user's direct line-of-sight.
 The horizontal mounting wall 84 has a mirrored surface 88, preferably
 silvered or otherwise reflectively coated. The inclined wall 86 is a clear
 polished surface and receives the images reflected by the surface 88 for
 internal reflection to the front wall surface and refraction to the user.
 It will be appreciated that the prisms are effective for providing a
 redirected field of vision 14, substantially normal to the line-of-sight
 16, as prescribed by the angularities between the prism walls. Various
 angularities may be adopted for accomplishing the foregoing. In the
 present invention, a substantially perpendicular redirection is preferred
 with the angles for achieving same being 70.degree. to 90.degree. for
 angle A, 60.degree. to 80.degree. for angle B and 20.degree. to 35.degree.
 for angle C, with 90.degree. for angle A. 67.50.degree. for angle B, and
 22.50.degree. for angle C being preferred. Additionally, the prisms were
 located symmetrically on the centerline at 1.2 inch spacing, a length of
 1.2 inch, and a base wall 86 of 1.1 inch.
 With the foregoing construction, the visor 20 and the depending prisms are
 effective for providing the redirected view. By locating all visible
 structural elements above the upper wall 86, and thus above the vertical
 visual cutoff, the remaining lateral and downward peripheral vision
 sectors are substantially unimpeded thereby avoiding a tunnel vision
 effect and allowing the user to carry on related activities with clear
 reference to surroundings.
 Having thus described a presently preferred embodiment of the present
 invention, it will now be appreciated that the objects of the invention
 have been fully achieved, and it will be understood by those skilled in
 the art that many changes in construction and widely differing embodiments
 and applications of the invention will suggest themselves without
 departing from the sprit and scope of the present invention. The
 disclosures and description herein are intended to be illustrative and are
 not in any sense limiting of the invention, which is defined solely in
 accordance with the following claims.