Radiant energy – Photocells; circuits and apparatus – Photocell controlled circuit
Reexamination Certificate
1998-12-02
2001-02-20
Le, Que T. (Department: 2878)
Radiant energy
Photocells; circuits and apparatus
Photocell controlled circuit
C250S559290, C359S557000
Reexamination Certificate
active
06191407
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of spatially stabilizing projected or viewed images which are projected or created from a film or other image bearing source onto a projection screen or suitable location wherein the image appearing thereat is subject to movement such as weaving or jitter resulting from imperfections in the projection system or image bearing source. The invention finds particular use for stabilizing projected optical images from film and television projectors, graphics printers or images photographed by a camera such as a still video or television camera.
In the presentation, viewing or capture of images, problems often occur which cause movement, jitter and/or distortion of the image. Electro mechanical and optical mechanical devices such as projectors and cameras are highly susceptible to such problems.
One of the most common of mechanical effects occurs with film projectors and is called gate weave in the motion picture industry. Gate weave results in a moving and jittery image being presented on the motion picture screen when the movie is projected due to slight movement of the projected film image. The main cause of gate weave in this instance is the improper positioning of the film image in the film gate or aperture of the projector from one frame to the next due to uneven wearing of the sprocket holes in the film occurring over prolonged use. The sprocket holes are used by the projector intermittent gear to position the film in the projector aperture for the momentary presentation of each frame, with the edges of the holes requiring critical alignment with respect to the film image. As the film is projected over and over, these edges tend to wear unevenly.
The parent application of this specification deals with an invention which can effectively correct the above problems. The present specification deals with an improvement to the previous invention which utilizes specific features of the image bearing medium in order to provide lower cost and/or higher performance corrections. In particular, the preferred embodiment of the invention finds considerable use with motion picture film which includes digital audio tracks.
2. Description of the Prior Art
In the Prior art it is known to apply considerable mechanical precision to the movement and holding of the image bearing or image receiving element of imaging systems. In particular film projectors having elaborately designed film movement and positioning mechanics are well known. In the field of acquiring images, such as in film and television cameras, elaborate types of vibration and movement damping mechanisms are used, these including electromechanical gyroscope mechanisms to hold the camera or its mounting platform steady.
It is also known in the television industry to electronically correct a jittering television image by the electronic process of moving the video image signal with respect to its horizontal and vertical synchronizing pulses with the aid of complex motion detection circuits and frame memory control. Such systems do not lend themselves to improvement of existing projection and camera equipment and in particular to the improvement of existing motion picture film and television projectors.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide improved performance with respect to the various objects of the parent specification.
It is an object of the invention to stabilize an image by sensing the position of a known feature of the image bearing source with respect to a reference and altering the conveyance path of the image in response thereto in order to improve the stability of the image.
It is another object of the invention to position an electromagnetic radiation image by sensing a feature on the image bearing source and altering the path of the electromagnetic radiation which creates the image in the first or a second form in order to improve the positional accuracy of the image.
It is a yet another object of the invention to stabilize an optical image by sensing the position of the image conveying medium and refracting the light which creates the image from the medium to another location in response thereto in order to improve the stability of the image.
It is still another object of the invention to sense a feature of the medium carrying an optical image to be stabilized, compare the position of the feature from one moment in time to another to determine a displacement value responsive to the displacement thereof in at least one dimension and changing an optical correction element located in the light path of the image in response to the displacement value to cause a compensating displacement of the image.
It is a further object of the invention to sense, before or during projection, the position of a series of projected features related to image frames to be stabilized during projection, compare the position of the feature corresponding to one frame to the image relative to the feature corresponding to another frame to determine a displacement value responsive to the displacement thereof and changing an optical correction element located in the light path of the projected image in response to the displacement value to cause a compensating displacement of the projected image.
It is yet a further object of the invention to sense the position of a non image feature corresponding to an image frame of motion picture film which is to be projected, compare the position of the feature relative to a desired position, and changing a correction element located in the projection path of the image in response to the position of the feature.
It is still a further object of the invention to sensing the position of a digital data portion of a motion picture film relative to a desired position and to modulate the position of the projected image from a frame of the film which has a known spatial relationship to the digital data portion in response to the position sensing in order to correct the projection of the image from the film frame.
It is further another object of the invention to use a position measure responsive to a known pattern located in digital sound data of a motion picture film to modify the projection of a film image from a film frame having a known spatial relationship to the sound data in order to position the projected image such as to reduce positional errors.
Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which:
REFERENCES:
patent: 3544207 (1970-12-01), John, Jr.
patent: 3753612 (1973-08-01), Okey
patent: 4296438 (1981-10-01), Stemme et al.
patent: 5194958 (1993-03-01), Pearman et al.
patent: 5544140 (1996-08-01), Seagrave et al.
patent: 5581404 (1996-12-01), Misaka et al.
patent: 5635725 (1997-06-01), Cooper
patent: 5793053 (1998-08-01), Cooper
Cooper J. Carl
Le Que T.
LandOfFree
Apparatus and method for spatially stabilizing projected or... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for spatially stabilizing projected or..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for spatially stabilizing projected or... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2584367