Patent Description:
Methods to rotate the lenses include a gear or cam to rotate the lenses. Using the gear method, the movement of the system is limited to a linear progression and does not achieve the most accurate results. The cam method relies on the use of return springs for one direction of rotation. The cam method lacks reliability because, due to environmental changes, the springs do not always have enough strength to overcome the resistance from the optical housings being driven and often fail. Further, springs may weaken over time and screws that attach the springs to the housings could loosen or back out. This method may also cause an inconsistent feel for the user due to increased spring tension at closer focus distances. Further, the close focus range is limited due to geometrical limitations of the system. <CIT>, <CIT>, and <CIT> disclose various cam lens devices.

Apparatuses, systems, and methods disclosed herein are directed to improving a cam system. Embodiments disclosed herein utilize slots in a cam body that may eliminate the need for return springs. A more consistent focus feel may be provided for the user.

An embodiment disclosed herein includes a cam for applying movement to a lens system. The cam comprises a body configured to couple to the lens system and having a first slot and a second slot, the first slot configured to receive a first lens follower, the second slot configured to receive a second lens follower, the first slot and the second slot extending in directions that are convergent relative to each other.

An embodiment disclosed herein includes a lens system comprising a first lens, a second lens, and a cam. The cam includes a first slot and a second slot, the first slot configured to couple to the first lens and the second slot configured to couple to the second lens such that axial movement of the cam causes the first lens and the second lens to rotate in opposite directions from each other.

An embodiment disclosed herein includes a method comprising providing axial movement of a cam to rotate a first lens and a second lens in opposite directions from each other. The cam includes a first slot and a second slot, the first slot being coupled to the first lens and the second slot being coupled to the second lens.

As digital technology evolves the need for higher quality lenses to match larger sensor are in great demand. An object of the disclosure is to provide a drive cam to operate a counter rotating lens system that achieves a higher level of precision than was possible with previous designs. An object of the disclosure is to provide a cam that reduces the need for return springs, so that the system is more robust and reliable. An object of the disclosure is to achieve a shorter close focus distance than was previously possible with a spring system. An object of the disclosure is to provide a cam that reduces resistance to a lens system and may achieve a smooth consistent feel throughout an entire focus range.

Features and advantages of the systems, apparatuses, and methods as disclosed herein will become appreciated as the same become better understood with reference to the specification, claims, and appended drawings wherein:.

<FIG> illustrates a prior art embodiment of a lens system <NUM>. The lens system <NUM> includes lenses <NUM>, <NUM> and a cam <NUM>. The lenses <NUM>, <NUM> and cam <NUM> are coupled to a housing <NUM> of the lens system <NUM>.

The lens system <NUM> is an anamorphic lens system, and the lenses <NUM>, <NUM> are each cylindrical lenses. The anamorphic lens system is designed to counter-rotate the lenses <NUM>, <NUM> during focusing, to reduce optical aberrations, and particularly reduce astigmatism caused by the anamorphic lens system during focusing.

The cam <NUM> includes a body <NUM> with working cam surfaces <NUM>, <NUM>. The working cam surfaces <NUM>, <NUM> are configured to contact respective lens followers <NUM>, <NUM> that are each coupled to respective lenses <NUM>, <NUM>.

The cam <NUM> is configured to move axially, along the optical axis. The axial movement corresponds to a focusing operation of the lens system <NUM>. Upon the cam <NUM> being moved axially in a direction away from the object space <NUM> (the space containing the objects or areas to be imaged), the working cam surfaces <NUM>, <NUM> press against the respective lens followers <NUM>, <NUM>. The forces against the lens followers <NUM>, <NUM> rotate the lenses <NUM>, <NUM> in opposite directions. The counter-rotation of the lenses <NUM>, <NUM> reduces optical aberrations during focusing.

Springs <NUM>, <NUM> are coupled to respective lenses <NUM>, <NUM>. The respective springs <NUM>, <NUM> apply a force to the lenses <NUM>, <NUM> in an opposite direction than the force applied by the working cam surfaces <NUM>, <NUM>. <FIG> illustrates the springs <NUM>, <NUM> stretching as the cam <NUM> moves axially to rotate the lenses <NUM>, <NUM>.

<FIG> illustrates the prior art embodiment of the lens system <NUM> in which the cam <NUM> has moved to its maximum axial position. The working cam surfaces <NUM>, <NUM> have pressed the respective lens followers <NUM>, <NUM> such that the lenses <NUM>, <NUM> are at a greater rotation relative to each other than shown in <FIG>.

The springs <NUM>, <NUM> are stretched to a greater extent than shown in <FIG>. Upon the cam <NUM> being moved in an opposite axial direction (towards the object space <NUM>), the springs <NUM>, <NUM> rotate the lenses <NUM>, <NUM> back towards a position shown in <FIG>. The lens followers <NUM>, <NUM> follow the profile of the working cam surfaces <NUM>, <NUM> as they rotate back towards a position shown in <FIG>.

<FIG> illustrates a top view of the prior art cam <NUM> that is shown in <FIG> and <FIG>. The working cam surfaces <NUM>, <NUM> are configured to only apply a force outward from the body <NUM> of the cam <NUM>.

<FIG> illustrates a front view of the prior art cam <NUM>, shown in relation to the lens system (marked in dashed lines). The prior art cam <NUM> has a curvature to accommodate the shape of the lens system.

The prior art lens system <NUM> suffers from a series of limitations. The use of the springs <NUM>, <NUM> may lead to mechanical error and lack of precision. The springs <NUM>, <NUM> may weaken over time or may become dislodged. The mechanical strength and resilience of the springs <NUM>, <NUM> may also vary based on temperature. For example, cold weather affects the grease in the metal housings, used to lubricate the movement of the glass inside the housing. Temperature impacts the viscosity of the grease. Extreme temperatures may make the springs brittle or otherwise vary their strength. Variations in the strength of the springs <NUM>, <NUM> over time may also lead to inconsistent control of the rotation of the lenses <NUM>, <NUM>. Further, the use of springs <NUM>, <NUM> themselves may lead to inconsistent control because the resistive force of the springs <NUM>, <NUM> may vary depending on the distance that the spring is stretched. The prior art lens system <NUM> also provides a limited range of focus, and particularly does not allow for close focus distances.

<FIG> illustrates a top view of a cam <NUM> according to the present disclosure. The cam <NUM> includes a body <NUM> and a plurality of slots <NUM>, <NUM>. The slots <NUM>, <NUM> are each configured to receive a respective lens follower (shown in <FIG>). The slots <NUM>, <NUM> extend in directions that are convergent relative to each other. The slots <NUM>, <NUM> extend in directions that are non-parallel relative to each other. The cam <NUM> may be for applying movement to a lens system.

The body <NUM> includes an axial dimension <NUM> and a lateral dimension <NUM>. The axial dimension <NUM> is the dimension along the optical axis of the lens. The slots <NUM>, <NUM>, and particularly the respective working cam surfaces <NUM>, <NUM>, <NUM>, <NUM> of the slots <NUM>, <NUM>, may be symmetrical with each other. The slots <NUM>, <NUM> and respective working cam surfaces <NUM>, <NUM>, <NUM>, <NUM> of the slots <NUM>, <NUM> are symmetrical about a line of symmetry (marked as reference line <NUM>). The line of symmetry <NUM> may extend along the axial dimension <NUM>. The symmetry of the slots <NUM>, <NUM> and respective working cam surfaces <NUM>, <NUM>, <NUM>, <NUM> may allow each of the respective lens followers to follow an identical path. The slots <NUM>, <NUM> may have an identical path length for the respective lens followers to follow. The slots <NUM>, <NUM> extend in directions that are convergent upon the line of symmetry <NUM>.

The slots <NUM>, <NUM> may each have respective end portions <NUM>, <NUM>, <NUM>, <NUM>. For reference, end portions <NUM> and <NUM> may be referred to as "first end portions" and end portions <NUM> and <NUM> may be referred to as "second end portions. " Each of the slots <NUM>, <NUM> may extend from the first end portions <NUM>, <NUM> to the second end portions <NUM>, <NUM> in directions that are convergent relative to each other. The slots <NUM>, <NUM> are convergent as taken along the axial dimension <NUM>. As is shown in <FIG>, each of the slots <NUM>, <NUM> may extend from the second end portions <NUM>, <NUM> to the first end portions <NUM>, <NUM> in directions that are divergent relative to each other.

The convergence of the slots <NUM>, <NUM> towards each other results in the second end portions <NUM>, <NUM> being closer to each other than the first end portions <NUM>, <NUM> are to each other. A distance between the slots <NUM>, <NUM> decreases taken along the axial dimension from the first end portions <NUM>, <NUM> to the second end portions <NUM>, <NUM>, and increases taken along the axial dimension from the second end portions <NUM>, <NUM> to the first end portions <NUM>, <NUM>.

The slots <NUM>, <NUM> may be shaped such that an axial distance between lens followers retained therein remains the same, yet the lateral distance between the lens followers varies during axial movement of the cam <NUM>. The lateral distance between the lens followers varies on the path of the respective slots <NUM>, <NUM>, as taken along the axial dimension. This allows the cam <NUM> to rotate the lenses coupled thereto.

The working cam surfaces <NUM>, <NUM> of the slot <NUM> may extend parallel to each other and face opposite each other. The working cam surfaces <NUM>, <NUM> of the slot <NUM> may extend parallel to each other. Each of the slots <NUM>, <NUM> may be straight. The working cam surfaces <NUM>, <NUM> may be configured to rotate lenses (marked in <FIG>) in counter rotating directions, and the working cam surfaces <NUM>, <NUM> are configured to rotate the lenses in opposite counter rotating directions.

The slots <NUM>, <NUM> may form a triangular shape, as shown in <FIG>.

Each of the slots <NUM>, <NUM> extend at an angle relative to the axial dimension <NUM> and the lateral dimension <NUM>. The first end portions <NUM>, <NUM> may each extend at respective angles <NUM>, <NUM> relative to the lateral dimension <NUM>. The first slot <NUM> and second slot <NUM> are angled towards each other. The first slot <NUM> and second slot <NUM> extend at opposite angles relative to each other.

The body <NUM> may have a leading edge <NUM>, and trailing edge <NUM> and left and right side edges <NUM>, <NUM>. The edges <NUM>, <NUM>, <NUM>, <NUM> together may form a trapezoidal shape for the body <NUM>, and particularly an isosceles trapezoid shape as shown in <FIG>.

The body <NUM> may comprise a plate. The body <NUM> may be configured to couple to a lens system.

The cam <NUM> may include a mount <NUM> for coupling the cam <NUM> to a lens system. The mount <NUM> may comprise apertures in the body <NUM> as shown in <FIG>, or in other embodiments may comprise other forms of mounts such as screws, rivets, other forms of fasteners, or other mounts.

<FIG> illustrates a side perspective view of the cam <NUM>. The body <NUM> of the cam <NUM> may have a curvature as shown in <FIG>.

<FIG> illustrates a front view of the cam <NUM>. The body <NUM> of the cam <NUM> may have a curvature that matches the shape of the lens system. The body <NUM> of the cam <NUM> may curve about the optical axis. The body <NUM> from the left side edge <NUM> to the right side edge <NUM> may extend for about <NUM> degrees of the full circumference of the lens system. In one embodiment, the body <NUM> from the left side edge <NUM> to the right side edge <NUM> may extend for about <NUM> degrees of the full circumference of the lens system, which may comprise a longer focal length lens than the lens with the cam that extends for <NUM> degrees. In one embodiment, the body <NUM> from the left side edge <NUM> to the right side edge <NUM> may extend for about <NUM> degrees of the full circumference of the lens system.

<FIG> illustrates a top view of the cam <NUM> coupled to lens followers <NUM>, <NUM>. The slots <NUM>, <NUM> receive the respective lens followers <NUM>, <NUM>. The body <NUM> is coupled to the lens system via the mount <NUM>. A support extends through an aperture of the mount <NUM> to couple the body <NUM> to the lens system.

The lens followers <NUM>, <NUM> may each comprise rollers as shown in <FIG>. In other embodiments other forms of lens followers <NUM>, <NUM> such as knife-edge, flat-face, spherical-face, or other forms of followers may be utilized.

<FIG> illustrates a lens system <NUM> including the cam <NUM> and lenses <NUM>, <NUM>. The lenses <NUM>, <NUM> and cam <NUM> are coupled to a housing <NUM> of the lens system <NUM>.

Similar to the prior art lens system <NUM>, the lens system <NUM> may comprise an anamorphic lens system, and the lenses <NUM>, <NUM> may each comprise cylindrical lenses. The anamorphic lens system may be designed to counter-rotate the lenses <NUM>, <NUM> during focusing, to reduce optical aberrations, and particularly reduce astigmatism caused by the anamorphic lens system during focusing. The lenses <NUM>, <NUM> rotate in opposite directions from each other. The lenses <NUM>, <NUM> may rotate equally in opposite directions and may be held concentric to the optical axis. In other embodiments, the cam <NUM> may be utilized in a lens system that is non-anamorphic. The lenses <NUM>, <NUM> may be configured to be spherical lenses, or have another shape (e.g., aspheric) as desired. The lenses <NUM>, <NUM> may be configured for non-anamorphic capture and the rotation of the lenses may produce desired optical effects. The optical effects may include light filtering, or a magnification, among other optical effects.

The cam <NUM> is coupled to the lens system via a slide support <NUM>. The slide support <NUM> may have the form of an arm as shown in <FIG>. The slide support <NUM> may allow the cam <NUM> to slide axially, along the optical axis. The axial movement may correspond to a focusing operation of the lens system <NUM>. The slide support <NUM> may slide axially due to rotational movement of a support ring, which may be a focusing ring operated by a user. The slide support <NUM> may be coupled to a cam that drives the main movable focus group of the lens system.

Upon the cam <NUM> being moved axially in a direction away from the object space <NUM> (the space containing the objects or areas to be imaged), the inner working cam surfaces <NUM>, <NUM> press against the respective lens followers <NUM>, <NUM>. The lens followers <NUM>, <NUM> slide along the respective slot <NUM>, <NUM>. The forces against the lens followers <NUM>, <NUM> rotate the lenses <NUM>, <NUM> in opposite directions. The counter-rotation of the lenses <NUM>, <NUM> reduces optical aberrations during focusing.

In one embodiment, the cam <NUM> may be oriented <NUM> degrees around from the position shown in <FIG> such that the leading edge <NUM> faces towards the object space <NUM>. A similar operation of the cam <NUM> results. The orientation of the cam <NUM> may be provided based on the space available for the cam <NUM> in the lens system <NUM>.

<FIG> illustrates the lens system <NUM> in which the cam <NUM> has moved to its maximum axial position. The inner working cam surfaces <NUM>, <NUM> have pressed the respective lens followers <NUM>, <NUM> such that the lenses <NUM>, <NUM> are at a greater rotation relative to each other than shown in <FIG>. The lens followers <NUM>, <NUM> have moved to the first end portions <NUM>, <NUM> of the slots <NUM>, <NUM>.

The lens system <NUM> does not include springs to rotate the lenses <NUM>, <NUM> in directions opposite those shown in <FIG> and <FIG>. Rather, the outer working cam surfaces <NUM>, <NUM> are configured to press against the respective lens followers <NUM>, <NUM> to apply a force to the lens followers <NUM>, <NUM>. The force from the outer working cam surfaces <NUM>, <NUM> rotates the lenses <NUM>, <NUM> in directions opposite those shown in <FIG> and <FIG>. The axial movement of the cam <NUM> accordingly causes the lenses <NUM>, <NUM> to rotate in opposite directions from each other.

The cam <NUM> beneficially allows for the lenses <NUM>, <NUM> to be counter-rotated in multiple directions due to the presence of the slots <NUM>, <NUM>. The slots <NUM>, <NUM> allow each of the lens followers <NUM>, <NUM> to be pushed and pulled without the use of springs, as discussed in regard to the prior art of <FIG>. The use of the slots <NUM>, <NUM> reduces the mechanical error discussed in regard to the springs. The slots <NUM>, <NUM> may also enhance the movement precision of the lens system <NUM>, by allowing for specific working cam surface profiles to be utilized with the cam <NUM>. Fewer mechanical parts may also be utilized. The slots <NUM>, <NUM> may also increase the range of rotation of the lenses <NUM>, <NUM>, to improve the ability of the lenses <NUM>, <NUM> to provide for near focus. A more consistent focus feel may be provided for the user.

<FIG> illustrates a schematic representation of the operation of the cam <NUM>. The slots <NUM>, <NUM> extend at angles to the lateral dimension <NUM>. The angles <NUM>, <NUM> may extend between about <NUM> degrees to about <NUM> degrees. In one embodiment, the angles <NUM>, <NUM> may be less than about <NUM> degrees. In other embodiments, the angles <NUM>, <NUM> may be varied as desired. In one embodiment, the angles of the slots <NUM>, <NUM> relative to the lateral dimension <NUM> may vary along the length of the respective slot <NUM>, <NUM> between about <NUM> degrees to about <NUM> degrees. This may be an embodiment in which the slot <NUM>, <NUM> shape may be non-linear. The angles <NUM>, <NUM> may be determined based on the design of the lenses. The angles <NUM>, <NUM> may be determined based on the requirements of each lens at various focal lengths. The angles <NUM>, <NUM> may allow for greater control over the counter rotation of the lenses <NUM>, <NUM>.

<FIG> illustrates a top view of an embodiment of a cam <NUM> having a different working cam surface profile than shown in <FIG>. The cam <NUM> includes slots <NUM>, <NUM> having respective working cam surfaces <NUM>, <NUM>, <NUM>, <NUM>. The slots <NUM>, <NUM> are each configured to receive a respective lens follower (similar to the slots <NUM>, <NUM>). The slots <NUM>, <NUM> extend in directions that are convergent relative to each other. The slots <NUM>, <NUM> extend in directions that are non-parallel relative to each other. The slots <NUM>, <NUM> may have an identical path length for the respective lens followers to follow. The lateral distance between the lens followers varies on the path of the respective slots <NUM>, <NUM> as taken along the axial dimension.

The slots <NUM>, <NUM> and respective working cam surfaces <NUM>, <NUM>, <NUM>, <NUM> of the slots <NUM>, <NUM> are symmetrical about a line of symmetry (marked as reference line <NUM>). The line of symmetry <NUM> extends along the axial dimension <NUM> (rather than the lateral dimension <NUM>). The slots <NUM>, <NUM> extend in directions that are convergent upon the line of symmetry <NUM>.

Each of the slots <NUM>, <NUM> has a non-linear shape. The respective working cam surfaces <NUM>, <NUM>, <NUM>, <NUM> of the slots <NUM>, <NUM> each have a contoured profile. The contoured profile may allow the lenses <NUM>, <NUM> to rotate at varied rotation rates. For example, if a lens follower <NUM>, <NUM> moves from a respective end portion <NUM>, <NUM> to an opposite end portion <NUM>, <NUM>, then the lenses <NUM>, <NUM> may initially rotate rapidly and then have their rate of rotation slow. This is because the rate of change of distance between the slots <NUM>, <NUM> decreases along the axial dimension <NUM> from the end portions <NUM>, <NUM> to an opposite end portion <NUM>, <NUM> (towards the leading edge <NUM>). The contour of the working cam surfaces may be configured to produce a desired rate of rotation for the respective lenses <NUM>, <NUM>. The shape of the slots and contour of the working cam surfaces may be varied than shown in <FIG>. An optimized cam profile may be provided that the lenses may follow to achieve accurate results.

<FIG> illustrates a bottom view of the cam <NUM>.

<FIG> illustrates a top view of an embodiment of a cam <NUM> having a different direction of slots <NUM>, <NUM> than shown in <FIG>. The slots <NUM>, <NUM> are each configured to receive a respective lens follower (similar to the slots <NUM>, <NUM>). The slots <NUM>, <NUM> extend in directions that are convergent relative to each other. The slots <NUM>, <NUM> extend in directions that are non-parallel relative to each other. The slots <NUM>, <NUM> may have an identical path length for the respective lens followers to follow. The lateral distance between the lens followers varies on the path of the respective slots <NUM>, <NUM> as taken along the axial dimension.

The slots <NUM>, <NUM> and respective working cam surfaces <NUM>, <NUM>, <NUM>, <NUM> of the slots <NUM>, <NUM> are symmetrical about a line of symmetry (marked as reference line <NUM>). The line of symmetry <NUM> extends along the lateral dimension <NUM> (rather than the axial dimension <NUM>). The slots <NUM>, <NUM> extend in directions that are convergent upon the line of symmetry <NUM>.

Each of the slots <NUM>, <NUM> is straight. The slots <NUM>, <NUM> are shaped such that an axial distance between lens followers retained therein remains the same, yet the lateral distance between the lens followers varies during axial movement of the cam <NUM>. This allows the cam <NUM> to rotate the lenses coupled thereto.

The embodiments of cams disclosed herein may be configured to be separable from the lens system. For example, a plurality of cams may be utilized and swapped out in the lens system to provide a desired movement of the lenses. Each of the plurality of lenses may have a different slot shape, to provide the desired movement of the lenses.

The embodiments of cams disclosed herein may be utilized in a system, including a lens system. The lens system includes lenses, as disclosed herein, and other components that may allow for imaging. In one embodiment, the lens system may comprise a lens group that is separable from a camera. The entire lens system may be separable from the camera and replaced to provide a desired optical image capture. In one embodiment, the cams disclosed herein may be utilized in a camera system including a digital image sensor or a film capture aperture, or the like. The camera system may be either a film capture system or a digital capture system. The camera system may be used in the motion picture industry, or other industries as desired. The camera system is not limited to moving picture capture, but may include still photography capture, or mobile device capture (e.g., smartphone cameras, camera phones, or the like).

<FIG> for example, illustrates an embodiment of the lens system <NUM> removably coupled to a camera <NUM>. A housing cover <NUM> may cover the cam contained therein. The lens system <NUM> and camera <NUM> together may form a camera system <NUM>. The camera <NUM> may be a film capture camera or a digital capture camera, or other forms of cameras. The camera system <NUM> may be configured to capture in an anamorphic or non-anamorphic capture mode.

The slots disclosed herein may comprise apertures extending entirely through the cam bodies as disclosed herein. In one embodiment, the slots may not comprise apertures, but may comprise grooves extending along the cam bodies.

The shape of the cam bodies disclosed herein may be modified to accommodate the shape of the lens system that the cam is coupled to. The cam bodies may be oriented at a rotation of <NUM> degrees from the orientation shown in this application, or may be put at another orientation, to produce a desired effect.

The present disclosure includes methods of rotating lenses using the cams disclosed herein. The present disclosure also includes methods of utilizing any of the cams, systems, or other structures disclosed herein. Any of the processes or steps disclosed herein may comprise a method within the scope of the claims. For example, a method includes providing a cam including a first slot and a second slot, the first slot being coupled to a first lens and the second slot being coupled to a second lens such that axial movement of the cam causes the first lens and the second lens to rotate in opposite directions from each other. The method includes providing axial movement of the cam to rotate the first lens and the second lens in opposite directions from each other.

Unless otherwise indicated, all numbers expressing a characteristic, item, quantity, parameter, property, term, and so forth used in the present specification and claims are to be understood as being modified in all instances by the term "about. " As used herein, the term "about" means that the characteristic, item, quantity, parameter, property, or term so qualified encompasses an approximation that may vary, yet is capable of performing the desired operation or process discussed herein.

Claim 1:
A cam (<NUM>) for applying movement to a lens system (<NUM>) comprising:
a body (<NUM>) configured to couple to the lens system (<NUM>) and having a first slot (<NUM>) and a second slot (<NUM>), the first slot (<NUM>) configured to receive a first lens follower (<NUM>), the second slot (<NUM>) configured to receive a second lens follower (<NUM>), the first slot (<NUM>) and the second slot (<NUM>) extending in directions that are convergent relative to each other, the cam body (<NUM>) being configured to move axially along an optical axis (<NUM>) of the lens system (<NUM>) to cause the first lens follower (<NUM>) and second lens follower (<NUM>) to move within the respective first (<NUM>) and second slots( <NUM>).