Radiant energy – Photocells; circuits and apparatus – Photocell controls its own optical systems
Patent
1996-03-28
1998-02-03
Le, Que
Radiant energy
Photocells; circuits and apparatus
Photocell controls its own optical systems
2502061, 359601, G01J 120
Patent
active
057147515
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
There was a dual problem with conventional visors. On the one hand, they were too big. They blocked a very large area of the view. On the other hand, they were too small. The sun could still appear unblocked in sight. Both problems adversely affected driving safety and pleasure.
There were many improvements suggested in the prior art. Some suggested extendable visors; but they would block a larger area of the view, and the sun could still appear unblocked. Some others suggested movable visors or slideable extensions; but it was unsafe and inconvenient to manually move them in response to the movement of the sun. Some also suggested motorizing the visor and incorporating a photodetector, so that the visor would automatically move into its operative position when the sun appeared; but the systems did not have any directional sensitivity.
There were also many suggestions to add directional sensitivity to the visor system. Some suggested using a photodetector, such as: U.S. Pat. No. 3,226,151 issued to Reuther and U.S. Pat. No. 4,641,922 to Jacob. There were suggestions of multiple photodetectors, such as: U.S. Pat. No. 3,961,181 issued to Golden, Japan 55-68422 to Ogawa, U.K. 2090570 to Haardt, and U.S. Pat. No. 4,874,938 to Chuang. Instead of photodetectors, U.S. Pat. No. 4,892,394 issued to Bidabad suggested a compass means. Some of their shortcomings are summarized below.
With Reuther's system, the visor's operating position was fixed. It could not follow the movement of the sun in sight.
Jacob's system would require a substantial research effort to come up with proper tapering shapes for the lightshield and the liquid crystal panel. It was doubtful that the system could reliably work, for there were factors such as the weather that could affect the amount of sunlight received by the photodetector.
Golden's system could only track the sun in one dimension, and it would require a difficult mechanical calibration, most likely by trial and error, for the system to work for a particular driver in a particular placement of the seat. This system had another problem, i.e., the size of the zones, that will be described later.
Ogawa's system only tracked the sun in one dimension, and it required a semi-circular track, which was awkward to be installed on a car. It also required the driver to be seated at the center of the circle. It would not work, if the driver adjusted her seat off the center.
Both Haardt and Chuang suggested extending the visor when the sun appeared at a low elevation. This is undesirable because the visor would block a larger area of the view. In addition, Chuang's system had inherent problems with a small visor. The smaller the visor, the more precisely the system had to position the visor, which in turn required a higher resolution in tracking the sun. Therefore the monitoring territory for each DD (Direction Detector) must be smaller, and there must be more DD's. For example, to achieve 0.5.degree. resolution covering 190.degree. in azimuth angles and 45.degree. in elevation angles, it would need at least 34,200 DD's| Even if the system only supported 2.degree. resolution, it still needed more than 2,000 DD's. It would be very difficult to properly manufacture, mount, wire, and test so many DD's at a reasonably low cost. Moreover, even if we could assemble these DD's, it was still impractical to operate the system with a small visor, because there was no easy way to precisely locate the eyes. It would be very awkward for the driver to rely on a graduated ruler to measure the three-dimensional coordinates of her own eyes relative to the origin of some coordinate system, and then manually insert the coordinates in a certain devised format of instructions via the keyboard.
By nature, the compass means in Bidabad's system could not determine the elevation of the sun. In addition, if the system was calibrated as suggested to move the visor by one sector for every ALPHA degrees change in the heading direction of the vehicle, every sectors had to be properly arranged to
REFERENCES:
patent: 4874938 (1989-10-01), Chuang
patent: 5258607 (1993-11-01), Agostini
patent: 5305012 (1994-04-01), Faris
Emee, Inc.
Le Que
LandOfFree
Automatic visor for continuously repositioning a shading element does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Automatic visor for continuously repositioning a shading element, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automatic visor for continuously repositioning a shading element will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-664842