Optical device for producing a virtual image

#1. Field of the Invention

#The present invention relates to optical devices for providing decorative or entertaining visual effects, and in particular, to optical devices for projecting virtual images.

#2. Description of Related Art

#The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein:

#FIG. 1 is perspective view of an optical device in accordance with principles of the present invention;

#FIG. 2 is a side elevational view, partly in section, of the optical device of FIG. 1;

#Referring to FIGS. 1 and 2 an optical device is shown employing a box 10, which is about 18 inches (46 centimeters) long, although boxes of different sizes are contemplated, depending upon the available space, the size of the desired virtual image, etc. While a rectangular box is illustrated, other embodiments may employ boxes with shapes that are, at least in part, cylindrical, spherical, ovoid, polyhedral, etc. The inside of box 10 is coated with a light absorbing material such as a flat black paint.

#The front of box 10 has a window opening 12 fitted with two Fresnel lenses 14A and 14B, although other embodiments may employ fewer or more Fresnel lenses, a traditional lens with lenticular surfaces, or other types of lenses. Lenses 14A and 14B may be attached to the back of a ridge provided on window opening 12. The focal length of lenses 14A and 14B will be selected to produce the desired virtual image to be described presently. The height, width, and spacing between lenses 14A and 14B will be selected to produce a virtual image of the desired size and with a desired viewing angle. In this embodiment lenses 14A and 14B have an outline that is a 12 inch (30 cm) square, although other outlines having other dimensions are contemplated for other embodiments.

#Display object 16 inside box 10 is an internally illuminable hollow sphere, and in one constructed embodiment, was a plastic globe imprinted with Earth's geographical details. It will be understood that other display objects are contemplated having a variety of shapes and sizes. Globe 16 is mounted on a tilted spindle 18, which is rotated by electric motor 20 (also referred to as a motor mechanism) powered in turn by electrical line 22. It will be understood that the globe need not be tilted, rotating, or moving. Movement of the display object does, however, enhance the look of the resulting virtual image.