GB2338077A

GB2338077A - Optical glasses for viewing at an angle to the direct line of vision

Info

Publication number: GB2338077A
Application number: GB9804583A
Authority: GB
Inventors: David Irons
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-03-04
Filing date: 1998-03-04
Publication date: 1999-12-08
Anticipated expiration: 2018-03-04
Also published as: GB2338077B; GB9804583D0

Abstract

Optical glasses 4 for enabling a user to view objects at an angle to their direct line vision by means of a first portion while their gaze is feed in a substantially direct line of vision by means of a second portion. The user can switch between the two views by looking at the respective portions. An optical prism 9 may be used in conjunction with lens 6 in order for this to be achieved. The portions may be corrective or non-corrective lenses, tinted or sun glasses.

Description

1 PATENTS ACT 1977 P12143GB-ALM/LH 91nprovements in or relating to

glasses" 2338077 THIS rNVENTION relates to improvements in or relating to glasses and more particularly to glasses for cycling.

Cycling is a popular sport and pastime which has grown into different disciplines such as racing, touring and mountain biking. In all these disciplines the cyclist adopts a riding position, crouched over the handle bars to a greater or lesser extent depending upon the cycling discipline. For example, in the racing discipline, the cyclist adopts a very low and crouched position to achieve the most aerodynamic shape whereas in the touring and mountain biking disciplines, a more upright posture is adopted although, in the most natural position, the cyclist's head is still angled downwardly.

The most comfortable riding position is one in which the cyclist's head is held neutrally and the cyclist looks down to the ground to the front wheel of the cycle or one or two metres in front of the wheel - i.e. offering only a limited forward view of the road ahead. The result is that to ascertain where the cyclist is going, the cyclist must look up from the riding position by bending his/her neck upwardly so as to obtain a better view of the upcoming terrain, any obstacles to be avoided and the direction to be taken. Sometimes, for example when traversing difficult terrain when mountain biking or passing through a built up area when touring, the cyclist must either maintain a "head up" position for an extended period, or frequently look up to the road ahead. This 2 puts a strain on the cyclist's neck and makes for an uncomfortable riding position.

The problem is exacerbated for cycles with drop handle bars. When the cyclist adopts the most comfortable riding position when using drop handle bars the neutral position of the head is angled so far downwardly that the cyclist may be looking vertically down or even backwards. Thus, the extent of neck bend required to offer the cyclist an adequate forward field of view when using drop handle bars is extreme and very uncomfortable to maintain.

c it is an object of the present invention to seek to overcome the above mentioned problems and provide a comfortable riding position which offers a good forward view to the cyclist.

Accordingly, the present invention provides a pair of optical glasses comprising a first portion for providing a substantially non-refracted view along a first axis and a second portion providing a refracted view along a second axis, wherein, in use, the second axis is above the first axis and the wearer of the glasses can change between the two views by looking at the respective portions.

Conveniently, the second axis is in the region of 20 to 30' above the first c) axis.

Preferably, the second axis is in the region of 26' above the first ax Advantageously, the first and/or second portions are tinted.

Conveniently, the first and second portions are tinted different colours.

j Preferably, the glasses have a single elongate lens and the second portion extends along the width of the lens.

A further aspect of the present invention provides an optical prism attachable, in use, to a lens of a pair of optical glasses, the lens providing a substantially non-refracted view along a first axis and the prism providing a refracted view along a second axis, wherein the second axis is above the first axis and the wearer of the glasses can change between the two views by looking at the respective portions.

In order that the present invention may be more readily understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which:

FIGURE 1 is a schematic side view of a cyclist in an upright neutral position and various angles of sight of the cyclist in this position; FIGURE 2 is a schematic side view of a cyclist in a neutral crouched position and various angles of sight of the cyclist in this position; FIGURE is a front view of a pair of glasses embodying the present invention; FIGURE 4 is a side view of the glasses of Figure J3; and FIGURE 5 is a cross-section of a prism for use with the glasses of Figure 3.

4 Referring to Figure 1 in which a cyclist is shown in a substantially upright and neutral position, vanious angles of sight of the cyclist in this position are illustrated with reference to a horizontal line at eye level. In this example, it was established that, with the head in a neutral position, the eyes naturally looked at an angle of approximately 50' below the horizontal (line 1).

This position only provided a limited forward field of view. It was also established that the eyes were capable, in comfort, of looking upwardly from the natural position shown by line 1 to an angle of 14' above line 1 (line 2) for extended periods of time. The cyclist was not comfortable looking for extended pen' ods of time above line 2. Line 3) 1 s at an angle of approximately 16' below the honzontal and represents the line along which the cyclist would be afforded a forward field of view at approximately 15 metres ahead.

Referring now to Figure 2 in which a cyclist is shown in a fully crouched nding position using drop handle bars, various angles of sight of the cyclist in this position are illustrated with reference to a horizontal line at eye level. In this example, it was established that, with the head in a neutral position, the eyes naturally looked at an angle of approximately 50' below the honizontal (line 1). This position only provided a limited forward field of view. The eyes were capable, in comfort, of looking upwardly from the natural position shown by line 1 to an angle of 14' above line 1 (line 2) for extended periods of time. The cyclist was not comfortable looking for extended peniods of time above line 2. Line 3 is at an angle of approximately 5' below the honizontal and represents the line along which the cyclist would be afforded a forward field of view at approximately 15 metres ahead.

It should be appreciated that the above examples are for illustration purposes only, the various lines of sight and comfort positions varying between individuals and in dependence upon the particular riding position, the cyclist's height, the saddle height and the handle bar height.

A pair of glasses 4 embodying the present invention are shown in Figures 3 and 4. The glasses 4 in the example are non-corrective and comprise a pair of wrap around sunglasses of the type commonly worn by cyclists for protective purposes. The glasses 4 have a strip of frame 5 having a channel therein in which is fixed one edge of a single elongate lens 6. The lens 6 depends from the frame 5. A side arm 7 extends from either side of the frame 5. The side arms 7 are designed to sit on the cyclist's ears and are preferably, when the glasses are worn, biased towards one another to grip onto the cyclist's head. A nose bridge 8 is fixed to the lens 6 so that the glasses are supported in position on the cyclist's face. The above- described construction of the glasses is well known in the art.

The lens 6 is wide enough to extend across substantially all the cyclist's face and wraps around the face so as to protect the cyclist's eyes from wind, flying insects, dust and the like.

An optical triangular prism 9 is located adjacent to the frame 5 and extends fl-om one edge of the lens 6 to the other thereby spanning the lens 6. Preferably, the prism is moulded from a clear polycarbonate. Figure 5 shows the prism 9 in cross section. In the example shown in Figures 3 and 4, a first side 10 of the prism 9 is fixed to the lens 6. A second side 11, substantially normal to the first side 10 is fixed to the frame 5. The hypotenuse side 12 of the prism 9 subtends an angle of approximately 30 degrees to the first side 10. In the example of Figure 5, the first side 10 has a dimension of approximately 13min and the second side has a dimension of approximately 7min.

6 The effect of the prism 9 is to refract light from outside the glasses such that light fl-om the field of view above the point at which it becomes uncomfortable to look up for long periods of time (line 2 in Figures 1 and 2) is refracted to the cyclist's eyes. Thus, if the cyclist looks through the main portion of the lens 6 as normal, then a normal nonrefracted view will be seen and if the cyclist simply lifts his/her eyes upwards to the prism 9 at the top edge of the lens 6, then the cyclist will be afforded a field of view directly ahead, preferably to a distance of about 15m. This obviates the need for the cyclist to lift his/her head up from the comfortable riding position. Thus, the cyclist can remain in the riding position whilst being afforded a view of the road ahead.

Clearly, the angle of refraction required will vary in dependence upon many considerations such as the particular riding position, the cyclist's height, the saddle height and the handle bar height. However, it has been determined that refraction angles in the region of 20-30' are needed to achieve the desired effect - that is a difference of between 20-30' between the normal view through the main portion of the lens alone, a first axis and a refracted view through the prism along a second axis. A refraction angle in the region of 26' is appropriate in most cases. The construction of optical prisms with the requisite refractive properties is well known in the art.

The present invention is not limited to wrap around sun glasses and can be used with other styles of glasses and also with glasses with both corrective and non-corrective lenses.

The prism 9 can be formed as part of the moulding for the lens 6 or the frame 5 so as to be integrated with the glasses. Alternatively, the prism 9 can be manufactured separately for fitting onto the glasses, either by the Z:1 manufacturer, a retailer or the customer. It is envisaged that different prisms 7 could be sold having different refractive properties so that a particular prism would be chosen to meet the requirements of an individual or the discipline for which the glasses are to be worn.

The prism 9 may be tinted a different colour to the lens 6 so that the cyclist can identify the difference between the real view through the lens 6 and the refracted view ahead through the prism 9.

8

Claims

CLAIMS:

1. A pair of optical glasses comprises a first portion for providing a substantially non-refracted view along a first axis and a second portion providing a refracted view along a second axis, wherein, in use, the second axis is above the first axis and the wearer of the glasses can change between the two views by looking at the respective portions.

2. A pair of optical glasses according to Claim 1, wherein the second portion is an optical prism.

1 1 1 1 A pair of optical glasses according to Claim 1 or 2, wherein the first portion is a lens of a pair of glasses.

4. A pair of optical glasses according to any preceding claim, wherein the second portion is formed as part of the first portion.

5. A pair of optical glasses according to any one of Claims 1 to), wherein the second portion is formed separately from the first portion and is fixable to the first portion.

6. A pair of optical glasses according to any preceding claim, wherein the second axis is in the region of 20 to 30' above the first axis.

7. A pair of optical glasses according to Claim 6, wherein the second axis is in the region of 26" above the first axis.

8. A pair of optical glasses according to any preceding claim, wherein the glasses have a non-corrective lens.

9 9. A pair of optical glasses according to any one of Claims 1 to 7, wherein the glasses have a corrective lens.

10. A pair of optical glasses according to any preceding claim, wherein the glasses are sun glasses.

11. A pair of optical glasses according to any preceding claim, wherein the first and/or second portions are tinted.

12. A pair of optical glasses according to Claim 11, wherein the first and second portions are tinted different colours.

1 3). A pair of optical glasses according to any preceding claim, wherein the glasses have a single elongate lens and the second portion extends along the width of the lens.

14. A pair of optical glasses according to any preceding claim, wherein the second portion is located, in use, above the first portion.

15. A pair of optical glasses according to Claim 14, wherein the second portion is located, in use, at the top of the first portion.

16. An optical prism attachable, in use, to a lens of a pair of optical glasses, the lens providing a substantially non-refracted view along a first axis and the c prism providing a refi-acted view along a second axis, wherein the second axis is above the first axis and the wearer of the glasses can change between the two views by looking at the respective portions.

17. An optical prism according to Claim 16 in combination with a pair of optical glasses having a lens, the lens providing a substantially nonrefracted view along a first axis and the prism providing a refracted view along a second axis, wherein the second axis is above the first axis and the wearer of the glasses can change between the two views by looking at the respective portions.

18. A pair of optical glasses substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

19. An optical prism substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

20. Any novel feature or combination of features disclosed herein.