DE202011002776U1 - Fully immersed in liquid pressure stable and hermetically sealed flat Fresnel lens assembly with optical properties similar to those in a gaseous environment - Google Patents

Abstract

Completely immersed in pressure-stable and hermetically sealed flat Fresnel lens arrangement, characterized in that the arrangement of the Fresnel lens, which is placed with its structured side directly against a flat transparent counter plate and is tightly glued or welded to the edge. As shown in FIG. 1, the optically effective hermetically sealed air chambers thus arise and the arrangement thus has approximately the same optical properties within the liquid as when it was used in a gaseous environment

Description

The invention relates to a pressure-stable and hermetically sealed sheet-like Fresnel lens arrangement enclosed on both sides by a liquid medium, which moves directly into the liquid for sharp vision, magnification of objects and for all other optical functions, and thus only in their case if necessary Effect position can be brought.

For divers who have the eye problem of being farsighted, that is, needing reading glasses at close range (eg, diopter greater than +0.75) to see clearly, diving poses a risk of accurately reading the display of the dive computer and others instruments.

Even the sharp vision of the LCD display of cameras and video equipment in underwater housings is not possible for the farsighted without visual aid.

When diving, it is also not optimal to use the viewfinder of a camera to have the control image close to the eye.

According to the prior art, the glasses of the diving mask are usually ground in the lower area or lenses are glued within the mask to correct the farsightedness. The necessary refractive index difference is ensured by the air in the diving mask.

This takes some getting used to and requires a corresponding head posture when looking at a display. In addition, for the distant view under water then no longer the entire mask glass surface available.

If the mask is already filled to a small extent with water, the magnifying glass effect is lost in unfavorable head posture.

Other alternatives according to the prior art are described in patent DE4141364A1 or the utility model DE29720829U1 demonstrated. There is a permanent and completely installed over the glasses of the diving mask Sehoptik for the Nahbereich. In this case, however, the nearby environment under water blurs constantly and the farsighted diver would theoretically constantly change the mask during the dive. Furthermore, the lens curvature and thus volume and weight of the lens is also much larger to dimension than with air as the refractive index reference.

For the presentation of objects under water z. B. adhered to an aquarium half-convex lenses from the outside. However, if an object of interest is further away from the disk, optimal large-scale magnification is no longer possible in this way. If one were to use separate magnifying glasses for the enlargement of objects directly under water with magnification factors greater than two, these would have to be executed as a sealed aplanatic lens system, thus having an awkward thickness and, due to the round shape, only a small optically acting surface.

In picture 1 the principle of the large-area lens system with Fresnel lens is used here.

Only by juxtaposing the Fresnel lens ( 1 ) with its effect surface on a flat transparent counter-plate ( 3 ) and hermetic sealing of the edge (bonding, welding) ( 2 ) is due to the mechanically given flat shape of the lens and lack of housing in a simple manner a waterproof and pressure-stable very flat and lightweight optical lens system.

As materials preferably acrylic or other transparent light materials are to be used.

The design can be easily done with a lens and a plane transparent backplate or as an aplanatic lens system with two oppositely placed on the edge hermetically sealed Fresnel lenses. The remaining air in the closed circular air chambers between the many closely spaced concentric lens stages of the system ensures the refractive index difference necessary for the magnifying glass function.

In the air chambers, the pressure prevailing in the production air pressure remains. The relatively high density of the upper edges of the lens stages prevents mechanical breakage of the lens under water pressure at greater depths due to self-support on the opposite transparent plate. Since the back pressure must be intercepted and no deformation must occur, there must be a good mechanical stability of these edges on the lens surface.

Due to the generally flat design of Fresnel lenses, such an optical arrangement can be constructed over a large area.

This lens system can be made with very light non-brittle materials. A maximum required thickness of only about 1-2 mm is possible.

So that the lens system does not fog inside when used in a cold environment, condensable gas components in the air chambers of the lens system are to be kept low or to take other precautions in the production.

Optical arrangements with opposing Fresnel lenses with air entrapment are known, for. B. Patents DE19737107A1 and WO002005102830A1 ( US020060221298A1 . JP002006276321A )). Sealing in case of underwater use is only necessary within patent WO002005102830A1 to obtain the optical effect. The local arrangement of the Fresnel lenses in the dive mask, however, are invariably built-in lenses right and left for the corner of the eye to increase the visual angle at the edge, not the functionalities of the variable use of the Fresnel lens arrangement described here.

The Fresnel lenses are in the patent WO002005102830A1 Also not surrounded on both sides by water and there is no hermetic seal prescribed so that prevailing pressure under water also acts within the air chambers and only no water may penetrate.

• 1. Die flache und leichte Linse wird direkt vor der Tauchmaske im Wasser klappbar z. B. mit Scharnier, Klettband oder auf andere Art und Weise angebracht. So kann insbesondere ein weitsichtiger Taucher Displays vom Tauchcomputer und anderen Instrumenten aus einer Nähe von ca. 10 cm vor dem Auge vergrößert und scharf erkennen bzw. das LCD-Display einer Unterwasserkamera mit dem Effekt, wie durch den Kamerasucher zu schauen, betrachten. Wird die optische Funktion der Linse nicht benötigt, kann die Linse im Wasser zur Seite geklappt werden. Diese Funktionalität ist ebenfalls für Taucher ohne Weitsichtigkeit geeignet.
• 2. Die großflächige leichte Fresnel-Linsen-Konstruktion wird am Unterwassergehäuse im entsprechenden Abstand (ca. 10 cm) zum LCD-Display der Kamera fest oder klappbar montiert, um dieses, in der üblichen Entfernung vom Auge ungefähr 30–40 cm weit weg gehalten, scharf zu erkennen.
• 3. Die großflächige Fresnel-Linsen-Konstruktion wird für die Präsentation von Objekten unter Wasser im entsprechenden Abstand (ca. 10 cm) vor dem Objekt direkt im Wasser montiert.
• 4. Die großflächige Fresnel-Linsen-Konstruktion wird für Lichtstreuungen oder Lichtbündelungen von Scheinwerferlicht unter Wasser im entsprechenden Abstand und entsprechendem Vergrößerungsindex vor dem Scheinwerfer direkt im Wasser montiert.

In the following, different possibilities of use and functions of the described Fresnel lens arrangement under water are described:

• 1. The flat and lightweight lens is folded directly in front of the diving mask in the water z. B. attached with a hinge, Velcro or other means. In particular, a farsighted diver can enlarge displays of the dive computer and other instruments from a distance of about 10 cm in front of the eye and see sharply or look at the LCD display of an underwater camera with the effect of looking through the camera viewfinder. If the optical function of the lens is not needed, the lens can be flipped aside in the water. This functionality is also suitable for divers without farsightedness.
• 2. The large-area lightweight Fresnel lens construction is mounted on the underwater housing at the appropriate distance (about 10 cm) to the LCD display of the camera fixed or hinged to this, kept at the usual distance from the eye about 30-40 cm away to recognize sharply.
• 3. The large Fresnel lens construction is mounted directly in the water in front of the object for the presentation of objects under water at the appropriate distance (about 10 cm).
• 4. The large-area Fresnel lens construction is mounted directly in the water for light scattering or light bundling of headlamps underwater at the appropriate distance and magnification index in front of the headlamp.

All mentioned uses and functions are suitable for easy retrofitting of existing technology.

Description of the drawings:

1 shows the principle possible arrangements of the enclosed on both sides of water Fresnel lenses.

The first arrangement from the left shows the Fresnel lens ( 1 ) with the opposite flat transparent plate ( 3 ) hermetically sealed ( 2 ).

The second arrangement from the left shows two directly opposite hermetically sealed Fresnel lenses.

The third arrangement from the left shows two opposing hermetically sealed Fresnel lenses with a plane transparent plate as the support.

The fourth arrangement from the left shows the possibility of the cascaded expandable structure of the hermetically sealed Fresnel lenses.

The hermetic sealing can be done by gluing, welding or other means.

2 shows the foldable on the diving mask ( 2 ) mounted Fresnel lens assembly ( 1 ) for the right eye in the used state before the mask folded. Attachment is ( 3 ).

3 shows the attached to the diving mask hinged Fresnel lens assembly ( 1 ) for the right eye in the unused state to the side of the mask folded.

4 shows the fixed or hinged optical arrangement of the large Fresnel lens ( 1 ) behind the LCD display ( 2 ) of the camera in the underwater housing ( 3 ). The attachment ( 4 ) takes place on the underwater housing.

5 shows the visual acuity or magnification function using the example of reading the dive computer

6 shows the large-scale magnification function as a presentation stylized for anemones in the aquarium.

7 shows the light bundling by means of Fresnel lens arrangement ( 1 ) of headlight ( 2 ) under water, whose effort can be minimized in a simple manner without complex design measures and can retrofit existing headlights in a simple manner.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 4141364 A1 [0008]
• DE 29720829 U1 [0008]
• DE 19737107 A1 [0018]
• WO 002005102830 A1 [0018, 0019]
• US 020060221298 A1 [0018]
• JP 002006276321 A [0018]

Claims (9)

Completely characterized in liquid submerged stable under pressure and hermetically sealed flat Fresnel lens arrangement characterized in that the arrangement of the Fresnel lens, which is placed with its patterned side directly opposite a planar transparent counter plate and tightly bonded thereto at the edge or welded. As in 1 Thus, the optically effective hermetically sealed air chambers are formed and the arrangement thus has approximately the same optical properties within the liquid as when used in a gaseous environment Fully immersed in liquid pressure-stable and hermetically sealed flat Fresnel lens assembly, characterized in that the arrangement consists of two or more possibly aplanatisch to each other standing Fresnel lenses, which are glued tightly sealed against each other at the edge or welded. As in 1 shown, the corresponding optically effective hermetically sealed air chambers arise and the arrangement thus has approximately the same optical properties within the liquid, as in their use in air. Optical device with Fresnel lens according to the preceding claim 1, characterized in that by gluing or welding of other Fresnel lenses, as in 1 represented, in each case on the back of the previous a cascade-shaped structure can be achieved. Optical device with Fresnel lens according to the preceding claims 1 and 2, characterized in that the Fresnel lens assembly used because of their all-round fluid environment directly in the liquid, moves, adjusted and can be brought only in case of need in its operative position. Optical device with Fresnel lens according to the preceding claims 1 and 2, characterized in that the preferably made of transparent plastic with corresponding mechanical properties produced sheet-like optical Fresnel lens assembly due to lack of housing and by using a thin transparent plate, the arrangement with at most approx 2 mm thick filigree and pressure-resistant and hermetically sealed can be performed. Optical device with Fresnel lens according to the preceding claims 1 and 2, characterized in that a very simple attachment of this system with an approximately double magnification by means of hinge, Velcro or the like on a diving mask is possible and thus the required mobility for use in case of need is given, as in 2 and 3 shown. Optical device with Fresnel lens according to the preceding claims 1 and 2, characterized in that the mounting of the optical Fresnel lens assembly with an approximately double magnification on the underwater housing of a camera at a distance of about 10-15 cm to the LCD display directly in Water, as in 4 shown, done. The distance is adjusted constructively to achieve an optimum between visual distance to the display and the degree of farsightedness or the desired magnification. Optical device with Fresnel lens according to the preceding claims 1 and 2, characterized in that the large-area optical Fresnel lens arrangement is placed directly into the water for the enlargement of details in an aquarium is used. Optical device with Fresnel lens according to the preceding claims 1 and 2, characterized in that the Fresnel lens arrangement, directly in the liquid medium freely adjustable in front of lighting devices attaches to bring about light scattering or light bundling.

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