An examination of the characteristics of a converging lens and the images it creates

The Mathematics of Lenses Previously in Lesson 5ray diagrams were constructed in order to determine the location, size, orientation, and type of image formed by double concave lenses i. The ray diagram constructed earlier for a diverging lens revealed that the image of the object was virtual, upright, reduced in size and located on the same side of the lens as the object. But will these always be the characteristics of an image produced by a double concave lens? Can convex lenses ever produce real images?

An examination of the characteristics of a converging lens and the images it creates

The composite image may be two-dimensional or three-dimensional. Methods for providing such an imaged sheeting, including by the application of radiation to a radiation sensitive material layer adjacent the microlenses, are also disclosed.

Background of the Invention Sheeting materials having a graphic image or other mark have been widely used, particularly as labels for authenticating an article or document.


For example, sheetings such as those described in U. Other uses include graphics applications for identification purposes such as on police, fire or other emergency vehicles, in advertising and promotional displays and as distinctive labels to provide brand enhancement.

Another form of imaged sheeting is disclosed in U. Galanos discloses the use of a particularly "high-gain retroreflective sheeting of the exposed-lens type," in which images are formed by laser irradiation of the sheeting through a mask or pattern.

That sheeting comprises a plurality of transparent glass microspheres partially embedded in a binder layer and partially exposed above the binder layer, with a metal reflective layer coated on the embedded surface of each of the plurality of microspheres.

The binder layer contains carbon black, which is said to minimize any stray light that impinges on the sheeting while it is being imaged. The energy of the laser beam is further concentrated by the focusing effect of the microlenses embedded in the binder layer.

The images formed in the retroreflective sheeting of Galanos can be viewed if, and only if, the sheeting is viewed from the same angle at which the laser irradiation was directed at the sheeting. That means, in different terms, that the image is only viewable over a very limited observation angle.

For that and other reasons, there has been a desire to improve certain properties of such a sheeting. As early asGabriel Lippman invented a method for producing a true three-dimensional image of a scene in lenticular media having one or more photosensitive layers.

In Lippman's method, a photographic plate is exposed through an array of lenses or "lenslets"so that each lenslet of the array transmits a miniature image of the scene being reproduced, as seen from the perspective of the point of the sheet occupied by that lenslet, to the photosensitive layers on a photographic plate.

After the photographic plate has been developed, an observer looking at the composite image on the plate through the lenslet array sees a three-dimensional representation of the scene photographed. The image may be in black and white or in color, depending on the photosensitive materials used.

Because the image formed by the lenslets during exposure of the plate has undergone only a single inversion of each miniature image, the three-dimensional representation produced is pseudoscopic. That is, the perceived depth of the image is inverted so that the object appears "inside out.

These methods are complex, involving multiple exposures with a single camera, or multiple cameras, or multi-lens cameras, to record a plurality of views of the same object, and require extremely accurate registration of multiple images to provide a single three-dimensional image.

Further, any method that relies on a conventional camera requires the presence of a real object before the camera.

An examination of the characteristics of a converging lens and the images it creates

This further renders that method ill-adapted for producing three-dimensional images of a virtual object meaning an object that exists in effect, but not in fact. A further disadvantage of integral photography is that the composite image must be illuminated from the viewing side to form a real image that may be viewed.

Summary of the Invention The present invention provides a microlens sheeting having a composite image that appears to be suspended above or below the sheeting. These suspended images are referred to for convenience as floating images, and they can be located above or below the sheeting either as two or three-dimensional imagesor can be a three-dimensional image that appears above, in the plane of, and below the sheeting.

The images can be in black and white or in color, and can appear to move with the observer. Unlike some holographic sheetings, imaged sheeting of the present invention cannot be used to create a replica of itself Additionally, the floating image s can be observed by a viewer with the unaided eye.

The inventive sheeting having a composite image as described may be used in a variety of applications such as securing tamperproof images in passports, ID badges, event passes, affinity cards, product identification formats and advertising promotions for verification and authenticity, brand enhancement images which provide a floating or sinking or a floating and sinking image of the brand, identification presentation images in graphics applications such as emblems for police, fire or other emergency vehicles; information presentation images in graphics applications such as kiosks, night signs and automotive dashboard displays; and novelty enhancement through the use of composite images on products such as business cards, hang-tags, art, shoes and bottled products.

The present invention further provides a novel means of forming imaged sheeting containing the described composite images.Unlike converging lenses, diverging lenses always produce images that share these characteristics. The location of the object does not affect the characteristics of the image.

As such, the characteristics of the images formed by . An ophthalmoscope for observing an eye comprises a converging first lens system for generating a real intermediate image of a region in the eye in an intermediate image plane as well as an observation apparatus having an imaging optics for imaging the real intermediate image in an imaging plane in the observation apparatus and for imaging an aperture of the observation apparatus in a pupil of.

An optical lens creates either: A Converging beam – light is focused to a point However, detailed examination of the optical characteristics and diagrams for each are beyond the scope of this article.

This article concentrates on the basic lens shapes for convex and concave lenses. In the case of a converging lens (convex) the rays. Thin Lenses Types of Lenses: Converging and Diverging Lenses Thin lenses are devices whose centers are very thin.

Images are formed of an object about the types of images that can be formed from a lens. Here suffice it to say that we can still define the focal length of the lens. We take each of the two rays that emerge from the right hand.

Refraction and Lenses AP Physics B. Refraction A converging lens (Convex) takes light rays and bring them to a point. and real images ALWAYS are found on the OPPOSITE side of the lens from the object. Likewise, virtual images would appear on the SAME SIDE as the object.

An examination of the characteristics of a converging lens and the images it creates

Physics Review. STUDY. PLAY. A concave mirror with a focal length of cm creates a real image cm away on its principal axis. How far from the mirror is the corresponding object? All of the following images can be formed by a converging, lens except which one?

virtual, inverted, and same size.

Optical lens definition - Photokonnexion