GB2099170A

GB2099170A - Binoculars

Info

Publication number: GB2099170A
Application number: GB8113219A
Authority: GB
Original assignee: Combined Optical Industries Ltd
Current assignee: Combined Optical Industries Ltd
Priority date: 1981-04-29
Filing date: 1981-04-29
Publication date: 1982-12-01
Also published as: GB2099170B

Abstract

Simple and inexpensive binoculars comprise two tubular members (1,2) telescopically slidable together (or in a third tubular member), with a pair of eyepiece lenses (4) arranged transversely of one tubular member (1), and a pair of objective lenses (11) arranged transversely of the second tubular member (2). The lens pairs may be one-piece plastics mouldings (e.g. 3) with projections 7 receivable in recesses (8) in the tubular members to locate the mouldings. <IMAGE>

Description

SPECIFICATION Binoculars This invention relates to binoculars and, in particutar, provides a simple and inexpensive construction of binoculars which is especially suitable, for example, for children or for one-off use and disposal.

Binoculars are expensive items of equipment and are relatively heavy and bulky to carry around. They can be made to very high standards of distortionfree magnification but, for many ordinary purposes, this is not required.

We have now devised a binocular construction which can be made very cheaply and which can provide reasonable magnification with acceptably low distortion, and which is thus eminently suitable as a child's toy or for general purposes, e.g. sporting events and other outdoor activities, and theatres, where very high power and substantially distortionfree viewing is not essential.

According to a preferred aspect of the invention the binoculars comprise a pair of objective lenses mounted side by side in, and transversely of, a first tubular member, and a pair of ocular (eyepiece) lenses mounted side by side in, and transversely of, a second tubular member, the two tubular members being receivable together (or in a third tubular member) telescopically with each ocular lens aligned optically with a respective objective lens, to form a pair of binoculars, the focus of which is adjustable be telescopic relative motion between the said two members.

Preferably, the two (or three) tubular members are shaped so that they can only slide together in telescopic fashion when the respective ocular and objective lenses are in optical alignment. One construction by which this is achieved, and which is itself highly preferred for other reasons also, is one in which the two (or three) tubular members are of rectangular cross-section, i.e. box-shaped.

Conveniently (but not necessarily) the lenses are all of plastics material, and each pair of objective and ocular lenses can be made as a one-piece plastics moulding. The moulding preferably will have a peripheral shape matching the internal cross-section of the tubular member in which it is to be received, and may conveniently be arranged to engage positively with the tubular member (e.g. fit into slots therein) to locate the moulding transversely of the tubular member.

The tubular members can be made of metal, plastics, cardboard or other suitable material. We prefer to use stiff card since this is inexpensive and yet sufficiently rigid and durable for present purposes.

In addition, it is relatively easy and cheap to fabricate the binoculars from card.

The binoculars of the invention, in their simplest form, do not have any lenses other than the objective and ocular pairs, nor do they contain prisms or other light reflecting or refracting elements. How ever, other lenses, prisms etc can be provided if desired.

In order that the invention may be more fully understood, one embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure lisa perspective view of the assembled binoculars, and Figure 2 is a perspective view of a one piece plastics moulding of ocular lenses for use in the binoculars of Figure 1.

The binoculars comprise two tubular members, 1 and 2, of box-like construction, the open ends of which are received in telescoping fashion with member 1 snugly and slidingly engaging within member 2. A one-piece plastics moulding 3 (as shown in Figure 2) is mounted in the external end of member 1, transversely extending there across. The moulding 3 has lens portions 4 formed in a rigid plastics support 5 which has, at each short side upstanding side pieces 6 each formed with a projecting lip 7. Member 1 is formed with a pair of opposed slots 8 to receive the lips 7 and so hold the moulding 3 in position in the tubular member 1.

There is a similar arrangement at the open end of tubular member 2, the only difference being that the moulding 10 has objective lenses (as opposed to eyepiece lenses). As shown in dotted lines 11, these are largerthan lenses 4.

The distance apart of the eyepiece lenses 4 is not adjustable in the finished binoculars. Focussing is achieved by sliding members 1 and 2 relatively.

When not in use, member 1 can be pushed home into member 2 to provide a compact light-weight unit.

The tubular members, 1 and 2, are each preferably made of stiff card, by folding and securing an appropriate carton blank.

It will be appreciated that the construction ill ustrated and described is merely one example of the invention and that numerous modifications and changes can be made.

1. A pair of binoculars which comprise a pair of objective lenses mounted side-by-side in, and transversely of, a first tubular member, and a pair of ocular (eyepiece) lenses mounted side-by-side in, and transversely of, a second tubular member, the two tubular members being receivable together (or in a third tubular member) telescopically with each ocular lens aligned optically with a respective objective lens to form a pair of binoculars the focus of which is adjustable by telescopic relative motion between the said two members (and/or third member if present).

2. Binoculars according to claim 1, wherein the said two tubular members are slidably receivable together in telescopic fashion.

3. Binoculars according to claim 1 or 2, wherein the tubular members are of generally rectangular cross-section.

4. Binoculars according to claim 1,2 or 3, wherein the pair of objective lenses is formed as a unitary one-piece plastics moulding.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Binoculars This invention relates to binoculars and, in particutar, provides a simple and inexpensive construction of binoculars which is especially suitable, for example, for children or for one-off use and disposal. Binoculars are expensive items of equipment and are relatively heavy and bulky to carry around. They can be made to very high standards of distortionfree magnification but, for many ordinary purposes, this is not required. We have now devised a binocular construction which can be made very cheaply and which can provide reasonable magnification with acceptably low distortion, and which is thus eminently suitable as a child's toy or for general purposes, e.g. sporting events and other outdoor activities, and theatres, where very high power and substantially distortionfree viewing is not essential. According to a preferred aspect of the invention the binoculars comprise a pair of objective lenses mounted side by side in, and transversely of, a first tubular member, and a pair of ocular (eyepiece) lenses mounted side by side in, and transversely of, a second tubular member, the two tubular members being receivable together (or in a third tubular member) telescopically with each ocular lens aligned optically with a respective objective lens, to form a pair of binoculars, the focus of which is adjustable be telescopic relative motion between the said two members. Preferably, the two (or three) tubular members are shaped so that they can only slide together in telescopic fashion when the respective ocular and objective lenses are in optical alignment. One construction by which this is achieved, and which is itself highly preferred for other reasons also, is one in which the two (or three) tubular members are of rectangular cross-section, i.e. box-shaped. Conveniently (but not necessarily) the lenses are all of plastics material, and each pair of objective and ocular lenses can be made as a one-piece plastics moulding. The moulding preferably will have a peripheral shape matching the internal cross-section of the tubular member in which it is to be received, and may conveniently be arranged to engage positively with the tubular member (e.g. fit into slots therein) to locate the moulding transversely of the tubular member. The tubular members can be made of metal, plastics, cardboard or other suitable material. We prefer to use stiff card since this is inexpensive and yet sufficiently rigid and durable for present purposes. In addition, it is relatively easy and cheap to fabricate the binoculars from card. The binoculars of the invention, in their simplest form, do not have any lenses other than the objective and ocular pairs, nor do they contain prisms or other light reflecting or refracting elements. How ever, other lenses, prisms etc can be provided if desired. In order that the invention may be more fully understood, one embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure lisa perspective view of the assembled binoculars, and Figure 2 is a perspective view of a one piece plastics moulding of ocular lenses for use in the binoculars of Figure 1. The binoculars comprise two tubular members, 1 and 2, of box-like construction, the open ends of which are received in telescoping fashion with member 1 snugly and slidingly engaging within member 2. A one-piece plastics moulding 3 (as shown in Figure 2) is mounted in the external end of member 1, transversely extending there across. The moulding 3 has lens portions 4 formed in a rigid plastics support 5 which has, at each short side upstanding side pieces 6 each formed with a projecting lip 7. Member 1 is formed with a pair of opposed slots 8 to receive the lips 7 and so hold the moulding 3 in position in the tubular member 1. There is a similar arrangement at the open end of tubular member 2, the only difference being that the moulding 10 has objective lenses (as opposed to eyepiece lenses). As shown in dotted lines 11, these are largerthan lenses 4. The distance apart of the eyepiece lenses 4 is not adjustable in the finished binoculars. Focussing is achieved by sliding members 1 and 2 relatively. When not in use, member 1 can be pushed home into member 2 to provide a compact light-weight unit. The tubular members, 1 and 2, are each preferably made of stiff card, by folding and securing an appropriate carton blank. It will be appreciated that the construction ill ustrated and described is merely one example of the invention and that numerous modifications and changes can be made. CLAIMS

5. Binoculars according to claim, 2,3 or 4, wherein the pair of ocular lenses is formed as a unitary one-piece plastics moulding.

6. Binoculars according to each 4 or 5, wherein the or each said plastics moulding is received within an end of a respective one of said two tubular members, the peripheral shape of the or each moulding matching the internal cross-section of the respective tubular member to provide a snug fit therein.

7. Binoculars according to claim 6, wherein the or each moulding and its respective tubular member comprise one or more projections and corresponding recesses arranged to positively locate the moulding within, and transversely of, the tubular member.

8. Binoculars according to any preceding claim, wherein the tubular members are made of plastics material or stiff card.

9. Binoculars according to any preceding claim, which do not contain any lenses other than the said objective and ocular lenses nor any prisms or other light refracting or reflecting optical elements.

10. A pair of lightweight simple binoculars substantially as herein described with reference to Figures 1 and 2 of the accompanying drawing.