Abstract:
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.

Description:
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&#39;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&#39;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. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The above and other objects and advantages of the present invention will become apparent upon reading the following detailed description taken in conjunction with the accompanying drawings in which: 
     FIG. 1 is a front elevational view of optical glasses for providing a wearer with a redirected field of view in accordance with a preferred embodiment; 
     FIG. 2 is a side cross sectional view taken along line  2 — 2  in FIG. 1; 
     FIG. 3 is a vertical schematic view of the redirected field of view provided by the optical glasses of FIG. 1; 
     FIG. 4 is a bottom view of the optical glasses; and 
     FIG. 5 is a top view of the optical glasses. 
    
    
     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&#39;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° to 90° for angle A, 60° to 80° for angle B and 20° to 35° for angle C, with 90° for angle A. 67.50° for angle B, and 22.50° 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.