A digital camera imaging lens includes first, second and third lenses arranged in sequence from an object side toward an imaging surface side. The first lens is a meniscus lens having a positive power, whose convex surface faces the object side. The second lens is a meniscus lens having a negative power, whose concave surface faces the object side. The third lens is an aspherical lens having an inflection point on its object-side surface. An aperture stop is disposed between the first and second lenses. The imaging surface is defined by an element surface of a photosensor.
The present invention is a compact lens system for use as a wide-field photographic objective with small format digital image sensors having a pixel dimension less than 0.010 mm. The f-number of the lens system is 2.9740, and the effective focal length of the system is 3.85 mm. The full angular field of view of the lens system is 61 degrees, and the chief ray incidence angles on the image plane are less than 18 degrees. The system comprises three plastic lenses, each having two aspheric surfaces. At least one of the aspheric surfaces in the system is coated with a multilayer infrared cut-off filter for blocking infrared wavelengths from the image sensors. The lens system has a reduced sensitivity to manufacturing tolerances, particularly lateral misalignment of optical elements and surfaces.
A method for aligning the upper and lower centering bells of a lens doublet assembly machine is provided. In one example of the method, the method includes positioning an alignment tool with respect to a base plate of the lens doublet aligning apparatus; positioning an upper bell shaft with respect to the alignment tool, wherein the upper bell shaft includes an upper bell chuck at a lower end of the upper bell shaft; and tightening flexural bearings around an outer radial edge of the upper bell shaft, wherein the flexural bearings precisely hold the upper bell shaft into perpendicular alignment in the lens doublet aligning apparatus.
Systems for positioning a functional element, such as an optical lens, include a housing, a primary guide pin coupled to the housing, a functional group that includes the functional element, and a vibrational actuator assembly. The functional group is movably coupled with the primary guide pin and includes a first friction surface and a second friction surface. The first and second friction surfaces are oriented relative to one another at one of an obtuse angle and a straight angle. The vibrational actuator assembly is substantially registered relative to the housing and includes a first drive element and a second drive element. The first drive element is configured to interact with the first friction surface and the second drive element is configured to interact with the second friction surface. The vibrational actuator assembly operates to translate the functional group. Some embodiments include position sensing elements configured to detect position(s) of the functional element(s), and control system(s) configured to operate the actuators based on feedback from the position sensing system(s).
Embodiments of the present invention relate to systems and methods of position sensing that use a sensing target with a pattern of features thereupon, and to positioning modules and systems that position functional elements using such position sensing systems. A position sensing system includes an encoding module and a processing module. The encoding module has an active encoding region through which the sensing target is configured to move. Further, the encoding module is configured to generate a signal based on a portion of the sensing target within the active encoding region. The active encoding region has a dimension greater than the average critical dimension of the pattern of features. The processing module is configured to convert the signal generated into a position data based on an input range condition and an initial position condition.
An optical module includes a first optics group, a second optics group, and an image sensor, wherein the first optics group and second optics group are configured to provide an image having a focus and a magnification to the image sensor. In some embodiments of the present invention, a first optics assembly includes a first optics group coupled to a threaded portion of a first lead screw so that translation of the first lead screw results in translation of the first optics group along an axis of the first lead screw, a first actuator for rotating the first lead screw; and a first sensing target configured to permit detection of rotation of the first lead screw. In some embodiments of the present invention a second optics assembly includes a second optics group coupled to a threaded portion of a second lead screw so that translation of the second lead screw results in translation of the second optics group along an axis of the second lead screw, a second actuator for rotating the second lead screw, and second means for sensing configured to detect rotation of the second lead screw.
