Counterbalanced Camera-Image Stabilizer U.S Pat. 4,290,684

This is a mechanism developed by Steve Hines which compensates for the unsteadiness of hand-held cameras. The mechanism is balanced for shooting at any angle. The photographer is not aware of the mechanism other than getting sharper pictures. This mechanism is particularly useful in news-gathering video cameras shooting from helicopters, and for sports photography with telephoto lenses. The technique can also be used in camcorders, binoculars, and telescopes.

The mechanism compensates for pitch (vertical tipping) and yaw (side-to-side swing), and requires no electrical power, gyros, or warm-up time. This mechanism was developed by Steve at the Kodak Research Laboratories, and is the subject of a U.S patent which is assigned to Eastman Kodak.

The image-stabilizer mechanism is comprised of the camera body, the lens, film and holder, and three parallel rod legs. The lens and film are supported by the three parallel legs. If the camera is jiggled angularly to cause a pitch or yaw motion, inertia causes the lens and film to lag behind in their original locations, but the parallelogram legs cause the lens and film to follow the rotation of the camera housing, having the effect of the camera housing rotating around the internal camera parts.

Notice that when

the front of the camera body is pitched up or down, the mechanism's support legs remain at their previous angle (horizontal in this illustration). As a result, the lens remains on a line between the object and its image on the film. The only undesirable artifact is a slight de-focusing of the image at the edges, and only in proportion to the camera angle. The cameras in these drawings are shown at an exaggerated 5° angle for illustration; however, virtually all camera shake can be compensated with 1° of angle. The defocusing using this technique is negligible compared to traditional techniques. As can be seen in the table below, at 1° this mechanism maintains 76 times better focus than conventional mechanisms. The negligible defocusing is far outweighed by the benefit of shake compensation.

How it works:

Any movement can be described with lateral, vertical, and longitudinal translational motion, and pitch, roll and yaw rotary motion. The camera motions which have the most serious effect on image smear, are pitch and yaw. If the photographer tipped the camera down 1°, it would have the effect of an object at 50 feet, being lifted 10 inches. The shake-compensating mechanism shown compensates for ±5°, or a total of 10°, in both the pitch and yaw directions.

*Pictures are rarely affected from a rolling motion. It's not easy to roll a camera around the optical axis.

People rarely get shaky pictures from translational movement (linear shifting) of the camera, therefore translational-motion compensation is not needed. This mechanism can withstand, but is not affected by translational motion.

The mechanism uses an agile cone-and-cup support for the lens and film (the 2-axis version of a knife-edge hinge). The weight of the camera lens and lens board is used to counterbalance the film and film holder, therefore the system is in equilibrium at any angle.

To prevent the mechanism from over or under compensating camera shake, the distance between the lens and film supports matches the focal length of the lens. The mechanism is caged when not holding the shutter button, allowing the mechanism to float during exposure but otherwise be locked.

This product is not for sale. Do not contact us to purchase this product. This project is shown only as an example of past engineering services. Steve Hines currently offers consulting in the area of image stabilization and optical equipment design, as well as a variety of licensable technology.

HinesLab, Inc.

Glendale, California, USA

email: Steve@HinesLab.com

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