Television – Camera – system and detail – Support or housing
Reexamination Certificate
1998-02-19
2001-11-27
Garber, Wendy (Department: 2712)
Television
Camera, system and detail
Support or housing
C348S375000
Reexamination Certificate
active
06323903
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates generally to mounts for directional devices such as cameras, optical devices or laser devices, and specifically to a mount that provides independent orthogonal adjustment of panning alignment of such devices in a horizontal plane in combination with independent adjustment of rotation alignment of such devices about a vertical axis parallel to the optical axis.
BACKGROUND OF THE INVENTION
It is known in the art to use cameras having charge-coupled device (“CCD”) arrays to test the operation of liquid crystal displays (“LCDs”) such as may be found on many cellular telephones. As information is fed from the telephone to be displayed on the LCD, testing generally requires that the LCD actually displays the information in the way designed. A technique to enable such testing is to view the LCD with a CCD camera as the information is sent to the LCD. The signal from the camera can be compared with the information sent to the LCD to verify accuracy to a high degree of resolution.
It will be understood that it is important for the CCD array in the camera to be able to be accurately aligned with the LCD array to enable precise testing. If the scan lines on the camera can be lined up accurately with the pixels on the LCD, the testing software generally works much more predictably. Camera mountings in the art generally allow fine adjustment of the camera's field of view by “sweeping” or “panning” along both X and Y directions in the plane of the arrays, but do not allow fine adjustment of rotation about a Z-axis orthogonal to the plane of the arrays and parallel to the optical axis of the camera. Hereinafter, such rotational adjustment about the Z-axis shall also be referred to “Theta” adjustment, or adjustment in the “Theta axis”.
Prior art mounting devices are known to use translational stages to adjust position in X and Y directions. These stages consume significant space. Such prior art mounts also offer no Theta axis adjustment as a built-in feature, so that X, Y and Theta adjustment can be accomplished independently in a single device.
In addition to being large, prior art mounts tend to be very expensive. The large size and prohibitive expense of prior art mounts can be explained to some extent in that such mounts are almost universally designed for optical applications. There is a need in the art for a camera mount addressing the problems of digital testing in a confined space. In particular, it is sometimes desirable to place two or more CCD cameras in close proximity to test LCDs. The extravagant use of physical space by prior art mounts makes such multi-camera deployments very challenging.
Prior art mounts typically also lack locking mechanisms for holding the camera in place during and after adjustment and alignment. It is often desirable to move the entire testing assembly without upsetting the alignment.
There is therefore a need in the art for a camera mount independently adjustable in X, Y and Theta axes. A solution also providing compactness and cost economy will also provide measurable advantage, especially if multi-camera deployments are also enabled. A locking mechanism will provide further advantage towards preventing loss of alignment.
SUMMARY OF THE INVENTION
These and other objects, features and technical advantages are achieved by a three axis camera mount that provides rotational adjustment in X, Y, and Theta axes. All axes of rotation consist of two plates rotationally attached using spherical contact surfaces and adjusted by a fine pitch screw. X and Y rotation is required to pan the camera to align its field of view precisely. The Theta rotation is to compensate for the camera's inherent misalignment in the CCD position, which is often out of position by up to 3 degrees.
Each adjustable axis consists of two plates, a ball bearing and another spherical surface for the hinge, one or more spring-loaded retaining screws, and a fine pitch adjustment screw with a lock nut.
The invention has a locking capability. Using lock nuts on the adjustment screws means that there will not be any movement of the device during use or drifting over time.
The invention combines the three needed axes of adjustment in one device. The design further controls differential thermal behavior of the cooperating elements of the mount so as to minimize the effect of such thermal behavior on the alignment. In a preferred embodiment, thermal behavior is controlled by guiding differential thermal displacement via slots retaining one point of contact in each of the horizontal and vertical planes. Displacement is contained to axial directions (X, Y or Z) that are easily compensated for by adjustment.
The invention is very low cost. Ball bearings are used for the precise rotation axes. Machined features in the various plates serve as the other bearing surfaces.
Each camera is attached to a 3-axis mount that allows the maintenance technician to adjust the camera's field of view along X and Y axes independently. The mount further allows the operator to align the Theta axis independent of other adjustments.
In a preferred embodiment, the angular range of camera motion for each adjustment is approximately plus or minus 5 degrees. The threads on the adjustment screws are selected to give an approximate resolution of 0.358 degrees of camera rotation per turn of the screw. This corresponds to a panning motion for the camera's field of view of 1.5 mm to 2.5 mm per turn of the screw (depending on the distance of the mount from LCD).
The camera is connected to the mount using a camera-specific mounting plate. This enables the mount to be used with different cameras.
Each mount contains a baseplate rigidly mounted to the fixture. The horizontal motion plate (providing X and Y adjustments) is attached to the baseplate. The vertical support plate is fixed to the horizontal motion plate. The vertical motion plate (providing Theta adjustment) is attached to the vertical support plate. The camera-specific mounting plate is fixed to the vertical motion plate, and the camera is mounted to it.
The mount is also designed to accommodate multi-camera deployment with minimal adaptation. In a preferred embodiment, the L-shaped base plate is reversible. The mount may be assembled on the base plate whether the base plate is disposed “right side up” or “upside down,” thus allowing two cameras to be placed side by side in within a “U” configuration formed by adjacent L-shaped base plates. This feature makes the invention extremely compact. Its nested design conserves space to the highest degree possible, while still allowing very fine, precision adjustment.
Reversibility of the base plate is enhanced still further in a preferred embodiment where the design is selected to keep the optical axis of the camera a constant distance from the vertical mounting surface regardless of whether the base plate is disposed “right side up” or “upside down.” In this way, cameras can be nested in a multi-camera deployment where the optical axes of the cameras are co-planar and parallel to the plane of the vertical mounting surface.
It is therefore a technical advantage of the present invention to provide a camera mount that is independently adjustable in X, Y and Theta axes.
A further technical advantage of the present invention is to contain thermal displacement of the mount to directions that are easily adjustable.
A still further technical advantage of the present invention is to be able to lock in an adjustment of the mount to preserve alignment.
Another technical advantage of the present invention is to provide a light and compact mount that is relatively low in cost to manufacture.
Another technical advantage of the present invention is to facilitate camera nesting in multi-camera deployments. A reversible base plate allows the same mount to be assembled on the base plate whether the base plate is disposed “right side up” or “upside down.” As a result, two cameras may be nested side-by-side in a within a combined “U” frame, advantageously also maintaining a co
Krajec Russell S.
Poulsen Andrew S.
Agilent Technologie,s Inc.
Garber Wendy
Nguyen Luong
LandOfFree
Three axis camera mount does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Three axis camera mount, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Three axis camera mount will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2613644