WO2013015929A1

WO2013015929A1 - Lens mount

Info

Publication number: WO2013015929A1
Application number: PCT/US2012/044236
Authority: WO
Inventors: Alex Ning
Original assignee: Alex Ning
Priority date: 2011-07-22
Filing date: 2012-06-26
Publication date: 2013-01-31

Abstract

A lens mount design is presented. The mount can be used on a variety of imaging systems but is targeted at small camera systems such as might be used on mobile phones, cameras, sports cameras, computers and computer peripherals where interchangeable lenses are currently not common place. Embodiments include different attachment mechanisms, environmental barriers and electrical connections.

Description

LENS MOUNT

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to the currently pending U.S. Provisional Application 61/510940, titled: Lens Mounting System, filed July 22, 2011, by the same inventor.

BACKGROUND OF THE INVENTION

TECHNICAL FIELD

The present invention relates to an interchangeable lens mounting system for compact camera systems and other applications. RELATED BACKGROUND ART

Digital imaging cameras use solid-state image sensors such as CCD or CMOS imagers to convert optical images into electronic signals. As the resolution of the imagers increases, there is a continuous need for optical lenses with increased performance. An important characteristic of the lens is the ability to produce high-resolution images across a wide field of view. Another important characteristic is to produce such high-resolution images using a lens that is of a compact size. The lenses are increasing being incorporated into a variety of electronic devices including mobile phones, cameras, sports cameras, computers and computer peripherals. Incorporation of the lenses into new devices also places new environmental performance requirements upon the lens. The lens must be compact and light, to be used in portable devices, and must maintain high performance characteristics. Multi-megapixel cameras incorporated in such devices have become commonplace. The performance must be stable with respect to vibrations and movement. The lens should also be made where possible of lightweight materials. The lenses should also be compact in both the axial as well as the longitudinal dimensions of the lens.

Inter-changeable lens mounting systems are standard features on traditional film and digital SLR cameras. They provide a convenient way for end-users to inter-change lenses. Wide-angle lenses may be used for example to capture landscape scenes, medium focus for portraits and telephoto lenses for wildlife and sports photography. Interchangeable lenses allow the user to adapt one camera body to multiple purposes. Currently known security cameras also use inter-changeable lens mount systems such as C-mount or CS-mounts. Though these existing systems work well for large lenses, they are not suited for miniature lenses used on compact cameras utilizing small format CCD/CMOS imaging sensors. The current systems also are not designed for rapid interchange of lenses in the field during use. Demands upon an interchangeable lens system include providing a lens mounting system that can be rapidly interchanged and still maintains precise alignment between the lens focal plane and the sensor image plane when the lenses are inter-changed.

Miniature lenses are often used in extreme environments. Use in sports such as skiing, kayaking and others where moisture contamination is a threat is common. A lens mounting system is needed that provides an environmental seal between the lens body and the lens holder.

Frequently, the image sensors or cameras use different settings depending upon the lens or application. Examples would be color balance, shutter speed, gain, aperture settings and autofocus settings. A lens mounting system is needed that provides a set of lens orientation independent electrical contacts between the lens body and lens holder. DISCLOSURE OF THE INVENTION

A lens mount system is described that addresses the aforementioned deficiencies in the prior art. The lens mount comprises a lens fixed in a lens body. The lens body includes a flange surface having a reference surface precisely located relative to the focal plane of the lens. The lens may be made of a single element or multiple lens elements. The term lens in the remainder of this description refers generally to either a single or multiple element lenses. The lens elements may be fixed or may be movable relative to one another within the lens body and movable relative to the focal plane as would be the case in a zoom lens or a lens that has an adjustable focus. Embodiments of the invention also include a lens holder. The lens holder is located in the proximity of the sensor with a reference surface that is precisely located relative to the sensor image plane. When the lens body is installed onto the lens holder, the reference surface of the lens holder is aligned with the reference surface of the lens body thus ensuring alignment and accurately defined distance between the lens and the image sensor. The term "alignment" means precise registration or placement of two objects in three dimensions with respect to x, y, z coordinates and rotations of the objects about these three axis. Embodiments use physical contact between the reference surfaces to provide the required precision alignment between the lens focal plane and the sensor image plane. In other embodiments the reference surfaces further include reference points to provide the required relative placement and alignment. In one embodiment the reference points are comprised of spring-loaded spheres such that the contact of threes spheres with a reference surface defines a reference plane. In other embodiments the spheres are replaced with hemispheres, sections of spheres and other geometric shapes that allow point contact. In another embodiment the reference points are machined raised areas or bulges that again when contacting a second surface, define a reference plane. In another embodiment the mating reference points comprise an indentation and a corresponding bump or spring loaded sphere (or other shape as discussed above) provide both planar alignment between surfaces as well as rotational orientation reference points. In another embodiment the alignment points provide planar alignment between the focal plane of the lens and the image plane of the sensor as well as rotational orientation to align electrical contacts located on the lens body and the lens holder. Mechanical or magnetic retaining features are used to secure the lens in place. A seal in the form of an O-ring or gasket made from suitable materials is located between the lens body and lens holder to provide environmental protection against dust/water from entering the space between lens body and the optical image sensor. A set of lens orientation independent electrical contacts between the lens body and lens holders is also provided. The lens mounting system of the present invention comprises a series of inter-changeable lens bodies all having a flange and a reference surface or a set of reference points precisely located relative to the focal planes of the lens. A lens holder located in the proximity of the sensor and a reference surface or a set of reference points that are precisely located relative to the sensor image plane. When the lens body is installed onto the lens holder, the reference surfaces on the two parts make physical contact to provide precision alignment between the lens focal plane and the sensor image plane.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic view of an imaging system in which the invention might be practiced. Figure 1A shows a schematic view of embodiments of the invention and a coordinate system. Figure 2 shows a first embodiment of a lens body and mount of the invention. Figure 3 shows a first embodiment of a lens holder and imager. Figure 4 shows the elements of Figures 2 and 3 combined.

Figure 5 shows a second embodiment of a combined lens body mount and lens holder. Figure 6 shows a screw mount embodiment of a lens body to a lens holder. Figure 7 shows a second version of a screw mount embodiment of a lens bod to a lens holder. Figure 8 shows an embodiment using spring-loaded pins to fasten a lens body mount to a lens holder. Figure 9 is another view of the embodiment shown in Figure 8.

Figure 10 shows an embodiment using a spring-loaded sphere in contact with a reference surface in the connection between a lens body mount and a lens holder.

Figure 11 is an end on view of an assembly using spherical contact points such as shown in Figure 10.

Figure 12 shows a second embodiment using spherical contact points with a different reference surface from that shown in Figure 10.

Figure 13 is an end on view of an assembly using spherical contact points such as shown in Figure 12.

Figure 14 shows an embodiment using spring-loaded spherical contacts on the embodiment of Figure 12.

Figure 15 shows an embodiment further including O-ring seal between the lens body mount and the lens holder.

Figure 16 shows a second embodiment including an O-ring seal. Figure 17 shows a third O-ring embodiment.

Figure 18 shows an O-ring embodiment using spring loaded connector pins.

Figure 19 shows an O-ring embodiment and spring loaded reference spheres.

Figure 20 shows an O-ring embodiment with reference spheres as shown in Figure 12. Figure 21 shows an embodiment further including electrical contacts between the lens body mount and the lens holder.

Figure 22 shows an embodiment including both O-ring seal and electrical contacts.

Figure 23 shows an embodiment including O-rings, electrical contacts and spring-loaded pins. Figure 24 shows an embodiment including O-rings, electrical contacts and spring loaded sphere reference points.

Figure 25 shows an embodiment showing O-rings, electrical contacts and spherical reference contact points.

Figure 26 shows three views of an embodiment showing a removable bracket for attachment of the lens body mount and the lens holder.

MODES FOR CARRYING OUT THE INVENTION

Referring to Figure 1 an exemplary imaging system in which the present invention may be used is shown. A lens 104 is mounted in a lens body 105 that is then mounted in a lens holder 101. The lens holder is attached to an image sensor 106. The sensor is typically mounted on a printed circuit board that provides means for an electrical connection 103 to image processing electronics 102. In another embodiment, not shown, the electronics 102 are incorporated on the same circuit board as the image sensor 106 thereby providing a very compact design.

Preferred embodiments of the invention include two general components a lens body and a lens holder. The lens body is removable from the lens body and may be interchanged with other lens bodies to provide a means for interchanging lenses. Lens bodies contain lens elements that are best used in differing imaging environments. For example one lens body may contain lens elements producing a wide-angle view and a second lens body may contain lens elements providing a telephoto view and a third lens body may contain lens element that are useful for very close-up or what is commonly known as macro imaging. An element of the invention is the ability to interchange these different lens bodies on the same imaging system. The lens holder is a component that acts as an adapter between the lens body and the imaging sensor. In one embodiment the lens holder is fixedly attached to the circuit board on which the image sensor is mounted. In another embodiment the imaging sensor is fixedly attached to the lens holder and the lens holder with the sensor are attached through electronic interconnects to the imaging electronics. Non-limiting examples of electronic interconnects include wires, contact pads on a circuit board including soldered interconnects, wire bonding and other techniques known in the art. Referring now to Figure 1A, a lens mount is comprised of a lens body 107 and a lens holder 108 that is designed to connect to the lens body. The lens mount allows removable attachment of a lens body to the lens holder and aligns the lens body focal plane with the image plane 109 (not clear on the drawing) of an image sensor 110 (not shown on the drawing). In a preferred embodiment the lens body and the lens holder are aligned and connected along the X and X' axis 111 as shown and the focal plane of the lens held within the lens body is aligned with the image plane of the sensor. In another embodiment, discussed in conjunction with Figure 29, the lens body and lens holder are fixed relative to one another along any arbitrary other axis and a mirror or mirrors are used to align the focal plane of the lens within the lens body with the image plane of the image sensor.

The position in space of the lens body is described by X, Y, and Z coordinates and rotation of the lens body around those coordinate axis as indicated by the rotation angles θχ, 9y and θζ. In a preferred embodiment, the optical axis of the lens within the lens body is along the X-axis. Also in a preferred embodiment, as shown in Figure 1A, the lens holder 108 is attached to the image sensor 110. The position in space of both the image plane of the image sensor and the position of the lens holder can therefore similarly be described by a Cartesian coordinate system (Χ', Υ', Ζ') and rotations (θχ', θν and θζ') about the three axis. The lens body and the lens holder include reference surfaces. The reference surface of the lens body is made to be in a known fixed relationship with the focal plane of the lens. The reference surface of the lens holder is made such that when the lens holder is attached directly or indirectly to an image sensor the relative locations of the lens holder reference surface and the image plane of the image sensor are precisely known and defined. Precisely known and defined means that location of the reference surface and the location of the focal plane are either known or fixed with respect to the Cartesian coordinates X, Y, Z and the rotations about these three axis. When the reference surface on the lens body is mated with the reference surface on the lens holder, the optical axis of the lens and the center of the image plane of the sensor are aligned and the image plane of the sensor and focal plane of the lens are coincident. Alignment therefore has the meaning that the coordinates X, Y, Z, θχ, 6y, and θζ of the lens body and the coordinates X', Υ', Ζ', θχ-, θγ- and θζ' are related such that the focal plane of the lens is centered on and coincident with the image plane of the sensor. The following specific examples show how this is accomplished with reference points and surfaces located on both the lens body and the lens holder. Although shown as cylindrical the lens body and lens holder need not be cylindrical. In some embodiments the location is defined with respect to all Cartesian and rotation coordinates. In other embodiments alignment means fixed with respect to Cartesian coordinates and two of the three rotations. In particular several embodiments allow free rotation about θχ while still maintaining alignment along all other coordinates. Referring now to Figure 2, a lens body embodiment is shown. The lens body 201 is a cylindrical structure shown here in a cross-section view. The object to be imaged 202 is located at distance 203 from the lens body 201. The focal plane of the lens 204 is located on the right side of the lens body. The lens body consists of lens elements 210 mounted in a cylindrical cavity 211. In a typical application there are more than one lens elements. The other lens elements, not shown, are contained within the lens body structure 211. In a preferred embodiment, the lens elements are mounted within the lens body such that the optical axis of the lens is coincident with the central axis of the lens body. The lens body further contains a flange structure 208 that is attached to the lens body structure 211. The flange structure optionally includes a cylindrical mounting portion 206. In a preferred embodiment at least one of the flange 208 surfaces 207, 209 are perpendicular to the optical axis of the lens and parallel to the focal plane 204. At least one of the flange surfaces is a reference surface that is located at a known distance 205, and, in fact at known coordinates in all Cartesian directions and rotations about the Cartesian coordinates as discussed in conjunction with Figure 1 A, relative to the focal plane. The precision alignment of the flange reference surface 207 to the lens focal plane 204 is achieved during assembly of the lens body. The distance 205 is a common aspect of all lenses regardless of the exact optical properties of the lens such as its focal length, back focal length, etc.. Since the flange surface is at a known distance 205 from the focal plane of the lens, the flange surface acts as a reference plane to precisely align other objects, such as the image plane of an image sensor, relative to the focal plane of the lens. The surface provides a reference not just for the distance 205 but also for placement relative to the two other axes perpendicular to the optical axis such that use of the flange surface as reference plane can ensure alignment of the focal plane of the lens with the image plane of the sensor with respect to three axes and rotations of the planes about the three axes. In some embodiments, since three points define a plane, the surface 207 can also be substituted by a set of three or more reference points on the flange 208. Though Figure 2 shows that the reference surface 207 is the right surface of the flange, in other embodiments, not shown in this Figure but discussed and shown later, the left surface 209 of the flange is used as the reference surface. In still other embodiments the reference surface is a plane defined by three reference points on the flange. Referring now to Figure 3 the second general component of the preferred embodiment, the lens holder, is shown. The lens holder 301 is mechanical structure that is meant to mate with the lens body discussed above. The lens holder is comprised of a cylindrical section 305 with flange 310 at one end of the cylinder. The other end 309 of the lens holder is attached to the substrate 306 upon which the imaging sensor 304 is attached. The lens holder is held fixed to the image sensor substrate with fasteners 307. Non-limiting exemplary fasteners include screws and rivets. In another embodiment the fasteners may be replaced with an adhesive applied at the interface between the lens holder flange and the substrate 306. A flange 310 located at the opposite end of the cylindrical structure of the lens holder is manufactured such that it is at a known distance 302 from the image plane 303 of the sensor 304. The flange 310 is also parallel to the image plane of the sensor. The flange 310 includes two flange surfaces 311, 312. In a preferred embodiment, at least one of the two flanges surfaces 311, 312 is both parallel to the image plane of the sensor and at a known distance from the image plane. The distance 302 in the illustrated case is measured to the outer surface 311.. One of the surfaces 311, 312 acts as reference surface to position the lens body at a fixed and known distance relative to the image plane of the sensor and in a preferred embodiment at a fixed orientation, namely parallel to the image plane of the sensor. In a preferred embodiment the central axis of the lens holder 314 is positioned to intersect the center of the image plane of the sensor 315 and perpendicular to the lens holder reference surface. The central axis of the lens holder coincides with the optical axis of the combined lens body and lens holder discussed below. Combined the lens body and lens holder form the lens mount as shown in Figure 4. The lens mount is comprised of a lens holder 405 and a lens body 411. The components of each of these elements separately were described in conjunction with Figures 2 and 3 above. In the embodiment shown, the lens holder and lens body are both cylindrical elements shown here in a cross-section view and the elements fit together concentrically. The lens body 411 is comprised of lens elements 401 which are fit in a central cylinder 412 such that the optical axes of the lens elements and the central axis of the cylinder in which the lens elements are mounted are coincident 415. In a preferred embodiment this line is positioned to intersect the center point of the image plane of the sensor 408. The lens body further includes a flange 403 the flange has surfaces 416 and 417. At least one of the flange surfaces is a reference surface that is at a fixed coordinates and rotation relative to the focal plane 418 of the lens. The lens body is fit within the lens holder 405 such that the outer surface of the cylindrical mounting portion of the lens body fits within the inner wall lens holder meeting at point 413. The inner surface of the lens holder and the outer surface of the lens body meet 413 to align the lens within the lens holder such that the optical axis of the lens 415 is aligned at the center point of the image plane of the sensor 408. In another embodiment shown in detail below, alignment of the optical axis of the lens with the center point of the image plane of the sensor is accomplished through use of indicia located on the lens body flange 403 and the lens holder flange 419. In the embodiment shown in Figure 4 the indicia, not shown, are located on the lens body flange surface 417 and the lens holder flange surface 406. The image sensor 408 is mounted to a substrate 410 through means already discussed above. The lens holder is attached to the same substrate 410 through the rightmost lens holder end 407 using connectors 414 again as already discussed. The dimension 409 of the lens holder and the location of the lens body flange 404 are manufactured such that when mated as shown the focal plane of the lens and the image plane of the sensor 418 are aligned. The surfaces 417 and 406 are manufactured to be reference surfaces that define the distance 402, as well as the other Cartesian coordinates and rotation angles relative to the lens focal plane and the sensor image plane. In this embodiment, the lateral position (in the y-z plane) of the lens focal plane is constrained by the clearance 413 between the lens body outer diameter and the lens holder inner diameter. The X, Y, Z coordinates as well as the tilt angles θχ, θγ and θζ of the focal plane of the lens contained within the lens body and the image plane of the sensor are constrained such that the focal plane of the lens and the image plane of the sensor are aligned.

There are several different methods used to hold the lens body in contact with the lens holder. In a first embodiment the clearance 413 is adjusted such that there is a friction fit between the lens holder and the lens body. In another embodiment the lens holder is manufactured from a permanent magnetic material and the lens body is ferromagnetic such that the magnetic attraction holds the flange surfaces 417 and 406 in contact. In another embodiment the lens body is made of a permanent magnetic material and the lens holder is ferromagnetic. In another embodiment both the lens body and the lens holder are permanent magnets and the polarity of the magnets are chosen such that the parts attract in the position shown in Figure 4. Finally in another embodiment magnets are embedded in either the flange surface 406 of the lens holder or the flange surface 417 of the lens body or both with the counterpart lens body or lens holder being ferromagnetic of the polarity of the magnets chosen such that the parts are magnetically held in the position shown in figure 4. Other means for removably attaching the lens body and lens holder are discussed below. In another embodiment shown in Figure 5, the flange on the lens holder further includes a guiding edge 505. The outer edge 508 of the flange 504 on the lens body abuts against the guiding edge 505 thereby centering the lens body 03 in the lens holder 509. In a preferred embodiment, the lens body is manufactured such that the optical axis of the lens elements 501 lies on the center axis of the lens body 510. The centering of the lens holder over the image plane of the sensor 506 ensures the optical axis of the lens aligns with the center of the image plane of the sensor. The intimate contact of the lens holder flange reference surface 12 with the lens body flange reference surface 511 assures that the distance 507 is set such that the image plane of the sensor is aligned with the focal plane of the lens. The contacting flanges 511, 512 ensure precise alignment of the lens in the X, Y and Z directions and control of the tilt (θγ and θζ> of the focal plane of the lens relative to the image plane of the sensor. The Cartesian coordinate system and angles are as previously described in conjunction with Figure 1 A. The surfaces of the guiding edge and the edge of the flange ensure precise centering of the lens over the image plane of the sensor. The embodiment shown in Figure 5 uses the same means of holding the lens holder in contact with the lens body as already discussed. In one embodiment friction fit at the interface is used to hold the lens body and lens holder together. In another embodiment magnetic forces are used to hold the lens body and lens holder together. In both embodiments the lens body is removably attached to the lens holder. To remove the lens, one simply unscrews the lens body from the lens holder.

Referring now to Figure 6 another embodiment of the invention is shown. The lens mount is comprised of a lens body 601 and a lens holder 602. The lens body includes lens elements contained within to form a lens and a flange 603 having a reference surface 606. The lens holder includes two flanges. A first optional flange 607 is used to connect the lens holder to a substrate 610. The first flange is optional in that other means to connect the lens holder to the substrate can be used to the same effect. A second flange 604 is intended to mate with the flange 603 of the lens body at reference surface 613. The lens holder further includes screw threads 611 that mate with screw threads 612 on the lens body. When the lens body is fully screwed into the lens holder the reference surface 606 of the lens body flange 603 meets reference surface 613 of lens holder flange 604. The distance 608 is set such that the focal plane of the lens is coincident and aligned with the image plane of the sensor 609. The image sensor 609 is attached to the substrate 610.

In another embodiment of Figure 6 the reference surfaces of the lens body and the lens holder are the threaded surfaces 611, 612. The location of these surfaces are precisely manufactured to be at known location with respect to the Cartesian coordinates and rotation angles as discussed in conjunction with Figure 1A. The reference surface 611 is defined relative to the focal plane of the lens and the reference surface 612 is defined relative to the image plane of the image sensor and when the reference surfaces 611, 612 are mated by screwing the lens body fully into the lens holder the focal plane and the image plane are aligned. Note that in this embodiment alignment in Y, Z, θγ and θζ are determined by the threaded reference surfaces 611, 612 and alignment in X and θχ is determined by reference surfaces 606, 613. In another embodiment, not shown, spacers may be placed between reference surfaces 606, 613 to accommodate lenses having different focal plane locations.

In another embodiment shown in Figure 7, a lens body 701 and a lens holder 702 both include screw threads 705. On the lens body the screw threads are located at the edge of the lens body flange 710. On the lens holder the threads are located on the inner surface of a guiding edge 704. The guiding edge is an extended structure and located on the lens holder flange 713. The mating of the reference surface 711 of the lens body flange with the reference surface 712 of the lens holder flange defines the distance 709 such that the focal plane of the lens is coincident with the image plane of the sensor 707.

As already discussed in conjunction with Figure 6 the threaded surfaces on the lens body and the lens holder are reference surfaces.

In another embodiment, shown in Figures 8 and 9, a lens mount is comprised of a lens body 801 and a lens holder 802 wherein the lens body and lens holder are removably held together by spring loaded guide pins. Two or more guiding pins are used to provide stability. Two pins are shown in Figures 8 and 9. The lens body includes a flange 805 with reference surface 803. The lens holder includes two flanges 808, 811. A first optional flange 811 is used to secure the lens holder to the substrate 812. The image sensor 810 is mounted to the substrate. The second flange 808 of the lens holder having a reference surface 816 meets with the flange 805 of the lens body such that when there is intimate contact between the flange's surfaces 803, 816 and the distance 809 is fixed such that the focal plane of the lens 803 and the image plane of the sensor 810 are aligned. The surfaces 803, 816 are reference surfaces.

The flange on the lens body 805 includes holes 815 that when the lens is properly seated align with holes 814 in the flange on the lens holder. Pins 813 fit through the aligned holes 814, 815. Each pin 813 is spring 807 loaded such that it is normally compressed against lens holder flange 808 surface. In the example two pins are used but in other embodiments a plurality of at least two pins are used. The pins and the holes align and fix the lens body and lens holder with respect to θχ. Referring now to Figure 9 a top view of the lens body flange of Figure 8 is shown. The hole in the lens body flange surfaces is seen to be non-circular. The hole in the lens body flange is a thru-slot. The shape of the thru-slots is such that the larger end 905 of the slot fits over the head or cap 906 of the guiding pin 909. The dimension 912 is larger than the dimension 911. The pin head 906 or cap has a sloped side 907. The height 914 of the pin cap is greater than the thickness of the lens flange 816 (see Figure 8). The lens body is removably installed by aligning the pin caps 906 with the larger ends 905 of the slots. When the lens is twisted 915 towards the smaller ends 904 of the thru-slots the spring-loaded guiding pins 909 are lifted away from the lens body flange surface as the tapered edge of the pin head 907 moves along the slot from the larger end 905 towards the smaller end 904. The inside surface 916 of the smaller end 904 of the thru-slot is tapered to match the slope 907 on the pin head. Once the pin head reaches the smaller end and the tapered area 916 the pin head drops slightly due to the compression of the springs. This serves as a detent feature providing a positive confirmation that the lens is installed properly. The spring loaded pins 909 snap the lens flange 902 in place providing a secure positioning of the lens body with respect to the lens holder. The lens is removed by twisting the lens in the other direction until the larger ends 905 of the slots are aligned with the pin caps 906, and the lens body is pulled away from the lens holder. The detents are also useful for providing resistance from accidental removal of the lens due to shock or vibration.

Another embodiment of the invention, shown in Figures 10 and 11 , uses spring-loaded balls where the left surface of the lens body flange is used as a reference surface. The embodiment is comprised of a lens body 1001 and a lens holder 1002. The lens body includes a flange 1003 the flange having a first reference surface 1005 and a second surface 1006. The lens holder includes a first optional flange 1013 and a second flange 1010. The first flange 1013 is attached to a substrate 1009 and an image sensor 1008 is attached to the substrate as well. The lens holder second flange 1010 further includes at least two structures (only one of which is shown in Figure 10) to engage the flange 1003 of the lens body. The first structure is comprised of a cavity 1011 in which is located a spring-loaded ball 1007. The structure on the lens holder flange further includes an edge guide 1014 that is perpendicular to the lens holder flange 1010. The structure further includes a tab 1004. The tab has two surfaces 1015, 1016 wherein when the lens body is installed in the lens holder one surface 1016 engages a surface 1005 of the lens body. These surfaces 1005, 1016 are reference surfaces that align the lens focal plane with the image sensor image plane with respect to the X, θγ and θζ coordinates. The surfaces 1016, 1005 are held in contact by pressure exerted by the spring-loaded ball against surface 1006 of the lens body flange 1003. The reference surface 1017 is located on the edge guide 1014 and the reference surface 1018 is the edge of the lens body flange 1003. When mated the reference surfaces 1017, 1018 align the focal plane of the lens with the image plane of the sensor in the Y, Z directions. Referring now to Figure 11, top views of the lens holder 1101 and the lens body 1102 are shown. The lens body flange 1107 is seen to include cut outs 1106 that are sized to fit past the tabs 1105 on the lens holder. The lens body flange further includes indentations 1109. The indentations are located on the lower surface 1006 (Figure 10) of the lens body flange 1101 and are sized to mate with the spring- loaded balls 1108 of the lens holder. In use the lens body is inserted into the central cavity 1103 of the lens holder with the cut-outs 1106 aligned with the tabs 1105. The lens body is then rotated in either direction 1110 until the spring-loaded balls 1108 engage the indentations 1109 of the lens body flange. The engage tabs and spring-loaded balls provide a detent or snap fitting of the lens body into the lens holder and removably secure the lens body to the lens holder. Although only three spring-loaded balls and tabs and indentations are shown in Figure 11, it is possible to use more spring-loaded balls to provide additional stability. The indentations and spring-loaded balls are reference points that align the focal plane of the lens and the image plane of the sensor with respect to θχ. The configuration as described will provide align the lens focal plane and the image plane of the sensor in the X, Y, and Z directions as well as θχ, θγ and θζ· This configuration fixes the rotational position around the optical axis θχ as well as the tilt angles for rotation about the Y and Z axis, θγ and θζ.

In another embodiment shown in Figures 12 and 13, the spring-loaded balls of Figures 10 and 11 are replaced with a spring clip and half- sphere contacts. This embodiment includes as do all others a lens body 1201 and a lens holder 1202. The lens holder is comprised of an optional first flange 1203 and a second flange 1204. The first flange 1203 is attached to a substrate 1210. An image sensor 1211 is also attached to the same substrate 1210. The lens holder further includes an edge guide 1205. Extending from the edge guide 1205 is a spring tab 1207. The spring is defined by use of flexible spring material at the outside corner edge 1206 of the tab 1207. Non- limiting exemplary material for the spring material include spring steel and high modulus plastics. Attached to the bottom of the spring tab 1207 is a hemisphere 1208. Non-limiting examples of the hemisphere material include plastic and metals such as aluminum and steel. The spring tab is loaded such that the sphere presses down on the surface 1213 of the flange on the lens body 1201. The lens body includes a flange 1204 having a first surface 1213 and a second surface 1214. When the lens body 1201 and the lens holder 1202 are fit together the lens body flange reference surface 1214 is pressed against the lens holder flange reference surface 1215 thereby determining the distance 1209 such that the focal plane of the lens and the image plane of the sensor are coincident. The edge of the lens body flange 1204 is also a reference surface that is indexed against the inside edge 1216 of the lens holder edge guide 1205 thereby positioning the lens body 1201 relative to the image sensor 1211 in the lateral Y and Z directions. In the preferred embodiment the lens body is positioned such that the center of the lens body and the center of the image plane of the sensor are coincident. The focal plane of the lens and the image plane of the sensor are thereby fixed in X, Y, Z, θχ, θγ and θζ, are mutually centered, coincident, and therefore aligned.

Figure 13 shows an end on view of the lens holder 1301 and the lens body 1302 described in conjunction with Figure 12 above. The lens holder includes a flange 1304 and spring tabs 1305. On the underside of the spring tabs are attached hemispheres 1306. The lens body flange 1307 includes cutouts 1308. The cutouts 1308 are sized to be larger than the tabs 1305 so that the with the cutouts aligned with the tabs, the lens body may be inserted into the cavity 1303 within the lens holder, over the top of the tabs to make contact with the surface of the lens holder flange 1304. Once contact is made the lens body is rotated in either direction 1310 until indentation 1309 on the lens body flange surface align with the hemispheres 1306 of the lens holder. The spheres then drop into the indentations under the force of the spring tab thereby snapping the lens body into position and providing a detent feel when the lens body is properly installed. The lens body may be removed by rotation in either direction 1310, aligning the cutouts 1308 with the tabs 1305 and lifting the lens body away. The hemispheres 1306 and the indentations 1309 are reference points. The configuration provides alignment through all coordinates including θχ rotation about the optical X axis.

A variation on the spring clip embodiment of Figures 12 and 13 is shown in Figure 14. This embodiment includes a lens body 1401 and a lens holder 1402. The lens holder includes two flanges 1403, 1404. The first flange 1403 is used to attach to a substrate 1410. The image sensor 1411 is also attached to the substrate 1410. The second flange 1404 includes at least two tabs 1407 (only one tab is shown in Figure 14). The tab projects from the flange 1404 and includes a wall 1414 perpendicular to the flange 1404 and a second projection 1408 attached to the wall to form a C-shaped section. On the inside of the C-shaped section is a spring-loaded ball that is contained in an indentation in the projection 1408. The spring-loaded ball presses against the flange 1405 of the lens body to hold the lens body flange 1405 against the lens holder flange 1404. When held in contact the distance 1406 is determined such that the focal plane of the lens is coincident with the image plane of the sensor 1411. Although not shown, the top view of the tabs of Figure 14 appear the same as the tabs and lens flange shown and discussed in Figure 13. Surface 1415 on the lens body flange is a reference surface that when mated with reference surface 1416 on the lens holder flange 1404 aligns the focal plane and the image plane with respect to X, θγ and θζ. Reference surfaces of the edge of the lens body flange and the wall 1414 mate 1417 to align the focal plane and the image plane with respect to Y and Z.

ENVIRONMENTAL SEALS

Frequently the lens mounts of the present invention are used in environments where it is advantageous to protect the inner workings of the lens and the image sensor. Examples would include damp or even completely immersed environments such as might be found where the lens is used as a sports camera. Figure 15 - 20 show embodiments that include the features already discussed and further include environmental seals.

Referring to Figure 15, a first embodiment of environmental seals is shown. A lens body 1503 including a lens 1501 and a flange 1504 is inserted into a lens holder 1502. In the embodiment shown both the lens body and the lens holder are threaded with mating threads 1 06 such that the lens body is screwed in to the lens holder until the flange 1504 on the lens body meets the flange 1510 on the lens holder. The mating surfaces on the flanges and the mating threaded surfaces are reference surfaces that align the focal plane and the image plane as already discussed. In other embodiments the lens body and lens holder are held together by for example magnetic forces, spring forces or friction fit all previously discussed. The seal 1507 is an O-ring or gasket made from suitable materials non-limiting exemplary materials include silicone, rubber, polyethylene, polypropylene and ethylene propylene diene monomer (EPDM). The seal resides inside a groove 1505 or pocket located on a surface of the lens holder. When the lens body flange surface 1504 is in contact with lens holder flange surface 1510, the seal 1507 compressed to form a dust/water barrier between the lens body and the lens holder. Figure 1 shows an embodiment where the seal is compressed in the thickness direction 1 11 between a surface of the lens holder 1513 and a surface of the lens body 1512. The compression ratio is determined by the depth of the groove 1505 and the diameter of the seal 1507 when uncompressed. In another embodiment the insertion leading edge 1 14 of the lens body is chamfered or curved (shown here with dashed lines) to facilitate the insertion. Alignment of the lens 1501 with the substrate 1509 and the image sensor 1508 is determined by machining of the threads 1506 and the machined surfaces of the lens body flange and the lens holder flange which fit flush together when the lens body is fully screwed into the lens holder. The relative location of the lens and the sensor are thereby accurately determined and aligned using machined surfaces while still allowing a compressed flexible fitting for an environmental seal.

In another embodiment shown in Figure 16, an O-ring seal 1606 is included in a groovel607 in the flange 1611 of the lens holder 1604. The alignment of the lens body 1601 with the substrate 1610 and the image sensor 1609 is determined by the mating of the surfaces of the lens holder flange and the lens body flange 1602. The lens body and lens holder are further aligned and held together with mating threads 1605 machined into the edge of the lens body flange 1602 and in an extension 1608 on the lens holder flange. The seal 1606 is made of a compressible material as discussed with Figure 15. Another embodiment shown in Figure 17 provides an environmental seal 1706 located in a cavity 1707 located in an extension 1705 of the lens holder flange 1704. The lens holder 1703 and the lens body are held together and aligned to the substrate 1710 and the image sensor 1709 by use of threads 1708 milled in the inside edge of the lens holder and the outside edge of the lens body. The alignment of the focal plane of the lens and the image plane of the sensor 1709 is defined by mating reference surfaces 1710 of the lens body flange 1702 and the lens holder flange 1704 and by the threaded reference surfaces mating at 1708.

In another embodiment shown in Figure 18, The lens body 1801 is held in contact with the lens holder 1803 through use of spring 1807 loaded pins 1806 that fit through openings in both the lens holder flange 1804 and the lens body flange 1802. The configuration and functioning of the spring loaded pins is as already discussed in conjunction with Figures 8 and 9 above. The environmental seal is provided with an O-ring 1808 embedded in groove 1809 located in the inner surface of the lens holder 1803. The lens body may optionally include beveled edges 1812 to aid in insertion of the lens body into the lens holder. The alignment of the focal plane of the lens with the image plane of the image sensor 1811 is determined by the mating reference surfaces 1813 of the lens holder flange 1804 and the lens body flange 1802.

In another embodiment shown in Figure 19 and environmental seal 1906 is added to a connection system analogous to that already discussed in conjunction with Figure 10 and 11 above. The embodiment is comprised of a lens body 1901 and a lens holder 1903. The lens body includes a flange 1902. The lens holder 1903 includes a flange 1904. The lens holder flange 1904 further includes at least two structures (only one of which is shown in Figure 19) to engage the flange 1902 of the lens body. The structure is comprised of a cavity 1910 in which is located a spring-loaded ball 1909. The structure on the lens holder flange further includes an edge guide 1905 that is perpendicular to the lens holder flange 1904. The structure further includes a tab 1908. When the lens body is installed in the lens holder, mating surfaces 1911 determine the alignment of the lens body 1901 and therefore the lens with the substrate 1912 and the image plane of the image sensor 1913. An environmental seal is formed upon insertion of the lens body into the lens holder through use of an O-ring 1906 that is enclosed in a groove 1907 located in the lens holder flange 1904.

Similarly an environmental seal may be added to the lens mount of Figures 12 and 13 by the additional embodiments shown in Figure 20. The lens body 2001 mates with a lens holder 2004 and aligns the lens body with the substrate 2009 and the images sensor 2008 when the surfaces 2007 of the lens body flange 2002 and the lens holder flange 2003 are in contact as shown. The environmental seal is provided by an O-ring 2005 located in a groove 2006 that is milled in the inner surfaces of the lens holder 2004.

ELECTRICAL INTERFACE

More advanced lenses incorporate active elements requiring electrical power and control signals to operate. Examples include auto-focus elements using liquid technology manufactured for example by Parrot societe anonyme (sa) of France, or liquid crystal based element manufactured by Lens Vector Inc, in USA. It is also possible to incorporate variable aperture or shutter, zoom and anti-vibration features driven by various motors or actuators in the lens body to further enhance the functionality of the lens. In all these cases, electrical power must be provided from the camera PCB board / substrate to the lens body. It may also be necessary to establish electrical communication between the lens body and the lens holder. In traditional film and digital SLR cameras, the electrical contacts are provided by a set of small contact pads located near the bottom of the lens body. A corresponding set of spring loaded contact pins is located inside the camera body. The prior art design requires that the lens orientation be controlled to a specific angle for the proper function of the electrical contacts. The present invention provides a method for achieving the required electrical contacts between the lens holder and the lens independent of the lens orientation. In the present invention a variety of means for making electrical contacts are described that may be used with the variety of lens body and lens holder designs already discussed including both the versions with and the version without environmental seals.

Figure 21 shows the preferred embodiment. Electrical conducting bands 2105, 2106 are formed around the outside diameter of the lens body 2101. The bands can be made from any suitable conducting material non-limiting exemplary materials include copper or aluminum. The bands can be made in the form of rings and attached to the outside diameter of the lens body or electro-plated directly on the lens body. Internal connections (not shown) are made from these bands to the active elements (also not shown) inside the lens body. The number of conducting bands depends in the number of connection required. Only two bands are shown in the figure. A matching set of spring loaded contact pins 2107, 2108 or conductive balls are located on the inner diameter of the lens holder 2103. The electrical pins are aligned with the corresponding bands when the lens is installed inside the lens holder. Electrical contacts are then achieved between the lens holder and lens body. Because the conducting bands are all around the outer diameter of the lens body, shown here in cross-section, the electrical contact is maintained independent of the lens body rotational orientation. The user can install the lens in all orientations (limited by the retaining mechanism) without aligning the lens in a specific angle. There are further electrical connections (not shown) between the lens holder and the substrate 2111. The substrate may then include active elements that control functionality included in the lens. Non- limiting examples of the functionality includes auto-focus, stabilization and the like. The electrical connections may also be used to provide identification of the lens included in the lens body to inform the image sensor 2100 and the associated image acquisition electronics of the type or even the particular lens that is attached.

In one embodiment information of the particular lens and lens parameters is encoded in a non- volatile memory device located in the lens body and the electrical connectors provide means to transfer that information to the circuitry on the substrate. Non- limiting exemplary memory devices include the 1- wire ® and ibutton ® devices sold by Maxim Integrated Products of Sunnyvale, CA. 1-wire and iButton are registered trademarks of Maxim Integrated Products. In one embodiment the information is a part number of the lens that includes focal length and other optical properties. In another embodiment the encoded information includes serial number for the lens. In another embodiment the encoded information includes correction factors to allow correction for aberrations in the image acquired by the image sensor. Such corrections would be specific to the lens used. The lens properties and correction factors are encoded in the memory device after manufacturing and calibration of the lens in the lens body.

The embodiment is shown with one of the several lens body and lens holder combinations already discussed. Parts now familiar include the lens body 2101, lens holder 2103, the flange on the lens body 2102 and the corresponding flange on the lens holder 2104. Alignment of the lens with the sensor is as already discussed. All other embodiments of the lens body and lens holder already discussed can further include electrical contacts.

Figures 22, 23, 24 and 25 all show other embodiments of the lens body and lens holder that further include environmental seals and now also include electrical contacts. In Figure 22 a lens body 2201 and a lens holder 2202 include flanges 2203 and 2204 with threads 2205 incorporated at the edge of the lens body flange 2204 and corresponding threads on an extension of the lens holder flange 2203. The embodiment includes environmental seal 2206 and now electrical contacts 2207 and 2208 in the lens holder and corresponding contacts 2209 and 2210 located on the lens body. The electrical contacts allow for electrical communication of data between the lens body and the substrate 2212 including the sensor 2211 and associated electronics on the substrate (not shown).

Similarly, Figures 23, 24 and 25 show other embodiments of the lens holder and lens body. Said embodiments discussed earlier but that now further include electrical contacts 2207, 2208, 2209 and 2210.

MECHANICAL PARTS VARIATIONS

The previous embodiments all showed the lens body and lens holder as two separate units but each unit appeared as integrated components of flanges, threads and fittings. This constraint is not required. Referring to Figure 26 three views of a mechanical variation on the embodiment shown and discussed in Figures 12 and 13 are shown. A lens body 2604 is seen attached to a lens holder 2610 the lens body includes a lens 2605 and a flange 2608 that when mated with a corresponding flange 2607 on the lens holder snaps the lens body in position in the lens holder. The lens holder flange further includes a protrusion 2612 that contacts the surface of the flange 2608 of the lens body. In one embodiment the flange 2608 on the lens body includes a dimple that when aligned with the protrusion 2612 "snaps " the lens into place with centrally aligned flanges. The flange 2607 on the lens holder is part of a separate element that is not made integral to the lens holder. The flange assembly is screwed 2609 to the lens holder to complete the assembly. The lens holder further includes bracket assemblies 2611 which are used to position and attach the lens holder to a substrate (not shown). The embodiment as shown provides alignment of the focal plane of the lens and the image plane of the sensor by fixing all three Cartesian coordinates as well as the rotational angles about all three axes. It should now be clear to one skilled in the art that all of the embodiments previously discussed may be manufactured of separate parts that are glued or screwed or otherwise attached together to create finished lens holders and lens bodies.

ISOLATE THE SENSOR

In another embodiment shown in Figure 27, the lens holder 2704 further includes a barrier 2708 that isolates the substrate 2709 and the sensor 2707 from the outside environment when the lens body 2701 is removed from the lens holder when, for example, changing lenses. Non-limiting exemplary material for the barrier 2708 include glass and optical grade plastics know in the art. The embodiment shown for the lens body and lens holder include the now familiar components of a lens body 2701, a lens holder 2704 a flange on the lens holder 2706 and flange on the lens body 2702 such that when the flanges meet 2706 the distance 2710 and orientation of the lens with respect to the image sensor 2707 are fixed. Ideally they are fixed such that the focal plane of the lens overlaps the image plane of the sensor. The additional embodiment of the barrier can be optionally added to all previously discussed variations of lens holders and lens bodies.

In another embodiment shown in Figure 28, the fixed barrier of Figure 27 is replaced with a mechanically actuated barrier 2808. The barrier is actuated by a lever 2811 that makes contact 2812 with the lens body 2801 upon insertion of the lens body 2801 into the lens holder 2804. In this embodiment the barrier 2808 is closed upon removal of the lens body and is opened by the actuator lever 2811 when the lens body is inserted. Non-limiting exemplary mechanical barriers 2808 include mechanically actuated irises and shutters as are known in the art. The embodiment includes the now familiar elements of a lens body 2801, a lens holder 2804, a flange on the lens body 2802 and a flange on the lens holder 2805. The flanges are manufactured such that when opposing surfaces are mated 2806, the distance 2810 and orientation of the lens body and therefore the lens is fixed with respect to the image sensor 2807. It should be apparent that the embodiment of the mechanically actuated barrier 2808 of Figure 28 could be included with all variations of lens body and lens holder already discussed.

NON-COLINEAR EMBODIMENTS

Referring now to Figure 29 a non-colinear embodiment is shown. The embodiment comprises as in all previous embodiments a lens body 2901 and a lens holder 2902. The lens body includes a flange 2906 said flange having at least one reference surface as previously discussed. The lens holder having two flanges 2907, 2908. The first flange 2908 attached to a substrate 2909 said substrate is fixed relative to a second substrate 2905. An image sensor is mounted on the second substrate. The embodiment further comprises a mirror 2903 that reflects the optical axis onto the image sensor. The embodiment otherwise is the same as the multitude of embodiments already discussed in that when the lens body is inserted into the lens holder the reference surfaces on each when mated will ensure alignment of the focal plane of the lens with the image plane of the sensor. It should be clear that the angle in the path of the optical axis 2910 although shown in the example as a 90 degree angel could be any angle, acute or obtuse, that still allows alignment of the focal plane and the image plane. Further although shown as a plane mirror 2903. It is clear that the mirror 2903 could also be nonplanar and in fact could be an active optical element.

Summary

A lens mount design is presented. The mount can be used on a variety of imaging systems but is targeted at small camera systems such as might be used on mobile phones, cameras, sports cameras, computers and computer peripherals where interchangeable lenses are currently not common place. Embodiments include different attachment mechanisms, environmental barriers and electrical connections. Those skilled in the art will appreciate that various adaptations and modifications of the preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that the invention may be practiced other than as specifically described herein, within the scope of the appended claims.

Claims

What is claimed is:

1. A lens mount for attachment to a substrate having an image sensor said image sensor having an image plane, said lens mount comprising: a) a lens body, b) lens elements forming a lens, said lens having an optical axis and a focal plane and mounted inside the lens body, c) a lens body flange attached to the lens body , said lens body flange having at least one lens body flange reference surface, said lens body flange reference surface is in a predetermined position relative to the focal plane, d) a lens holder having an inner cavity, e) a lens holder flange, f) a lens holder flange reference surface on the lens holder flange, said lens holder reference surface is in a predetermined position relative to the image plane when the lens holder is attached to the substrate, g) wherein the lens body is removably attached to the lens holder by insertion of the lens body into the inner cavity of the lens holder such that the lens body flange reference surface and the lens holder flange reference surface mate, and, h) when the lens body flange reference surface mates with the lens holder flange reference surface the focal plane of the lens and the image plane of the sensor are aligned.

2. The lens mount of claim 1 further comprising: a) a second reference surface on the lens holder flange, b) a second reference surface on the lens body flange, c) wherein when the lens body is removably attached to the lens holder and when the lens body flange reference surface mates with the lens holder flange reference surface and the second reference surface on the lens holder flange mates with the second reference surface on the lens body flange the focal plane of the lens and the image plane of the sensor are aligned, and, d) wherein alignment in Y and Z are determined by the second reference surface on the lens holder flange mating with the second reference surface on the lens body flange, e) wherein Y and Z refer to a Cartesian coordinate system describing the locations of the image plane and the focal plane, said Cartesian coordinate system arranged such that an X axis is along the optical axis of the lens.

The lens mount of claim 2 wherein the second reference surface on the lens body flange and the second references surface on the lens holder flange are threaded surfaces.

The lens mount of claim 1 further comprising at least one lens body reference point located on the lens body and at least one lens holder reference point located on the lens holder wherein when the lens body is removably attached to the lens holder and the lens body reference point is mated with the lens holder reference point the focal plane of the lens and the image plane of the sensor are aligned and alignment in θχ is determined by the mating of the lens body reference point and the lens holder reference point wherein θχ is rotation about the X axis in a Cartesian coordinate system describing the locations of the image plane and the focal plane arranged such that the X axis is along the optical axis of the lens.

The lens mount of claim 1 wherein the lens body is held in place in the lens holder by a friction fit between the lens body and the lens holder.

The lens mount of claim 1 wherein the lens body is held in place in the lens holder by magnetic forces.

The lens mount of claim 1 further comprising: a) at least two screws, said screws having heads located at a top end and shafts and bases at a bottom end, the head is larger in diameter than the diameter of the shaft and the heads are tapered from the top to the point of connection to the shaft and the shaft is located within a coil spring, the diameter of the spring being larger than the diameter of the shaft and smaller than the diameter of the heads and bases such that the spring is confined on the shaft, b) at least two ovoid hole in the flange of the lens body, the holes having a large diameter section and a small diameter section wherein the large diameter section is larger than the diameter of the top of the screws and the small diameter section is smaller than the larger diameter of the top of the screws and larger than the diameter of the shaft of the screw such that the large part of the hole fits over the top of the screw head and when the lens body is rotated the edges of the holes engage the tapered section of the screw head thereby slightly lifting the screws and compressing the spring, c) wherein the screw shafts pass through both the ovoid hole in the lens body flange and corresponding holes in the second flange of the lens holder such that when the lens body is rotated the spring compression pushes the reference surfaces on the lens body flange and the lens holder flange together thereby removably attaching the lens body to the lens holder and mating the reference surfaces to align the focal plane of the lens with the image plane of the sensor.

8. The lens mount of claim 1 further comprising an O-ring seal formed circumferentially around the lens body formed by placement of an O-ring within a scribed groove on the surface of the inner cavity of the lens holder.

9. The lens mount of claim 1 further comprising an electrical connector between the lens body and the lens holder, said electrical connector comprising circumferential strips of conductive material adhered to the lens body and spring loaded electrical connectors located on the surface of the inner cavity of the lens holder such that an electrical connection is completed when the lens body is inserted into the cavity of the lens holder.

10. The lens mount of claim 1 further comprising a mirror located in the optical axis of the lens and reflecting the focal plane of the lens onto the image plane of the sensor.

11. The lens mount of claim 10 where the mirror is not planar.

12. A lens mount for attachment to a substrate having an image sensor said image sensor having an image plane, said lens mount comprising: a) a cylindrical lens body having a central axis, b) lens elements forming a lens, said lens having an optical axis and a focal plane and mounted inside the lens body said optical axis coincident with the central axis of the lens body, c) a lens body flange attached to the lens body , said lens body flange having at least one lens body flange reference surface, said lens body flange reference surface is in a predetermined position relative to the focal plane and the optical axis, d) a cylindrical lens holder having an inner cavity said inner cavity sized to receive the lens body, e) a lens holder flange, f) a lens holder flange reference surface on the lens holder flange, said lens holder reference surface is in a predetermined position relative to the image plane when the lens holder is attached to the substrate, g) wherein the lens body is removably attached to the lens holder by insertion of the lens body into the inner cavity of the lens holder such that the lens body flange reference surface and the lens holder flange reference surface mate, and, h) when the lens body flange reference surface mates with the lens holder flange reference surface the focal plane of the lens and the image plane of the sensor are aligned.

13. The lens mount of claim 12 further comprising a second reference surface on the lens body and a second reference surface on the lens holder and when the lens body is removably attached to the lens holder by insertion of the lens body into the inner cavity of the lens holder the second reference surfaces also mate and when mated the focal plane of the lens is aligned with the image plane of the sensor in the x, y, z directions and rotations about x, y and z axes where x, y and z describe a Cartesian coordinate system with x along the optical axis.

14. The lens mount of claim 12 wherein the lens body is held in place in the lens holder by a friction fit between the lens body and the lens holder.

15. The lens mount of claim 12 wherein the lens body is held in place in the lens holder by magnetic forces.

16. The lens mount of claim 12 further comprising: a) at least two screws, said screws having heads located at a top end and shafts and bases at a bottom end, the head is larger in diameter than the diameter of the shaft and the heads are tapered from the top to the point of connection to the shaft and the shaft is located within a coil spring, the diameter of the spring being larger than the diameter of the shaft and smaller than the diameter of the heads and bases such that the spring is confined on the shaft, b) at least two ovoid hole in the flange of the lens body, the holes having a large diameter section and a small diameter section wherein the large diameter section is larger than the diameter of the top of the screws and the small diameter section is smaller than the larger diameter of the top of the screws and larger than the diameter of the shaft of the screw such that the large part of the hole fits over the top of the screw head and when the lens body is rotated the edges of the holes engage the tapered section of the screw head thereby slightly lifting the screws and compressing the spring, c) wherein the screw shafts pass through both the ovoid hole in the lens body flange and corresponding holes in the second flange of the lens holder such that when the lens body is rotated the spring compression pushes the reference surfaces on the lens body flange and the lens holder flange together thereby removably attaching the lens body to the lens holder and mating the reference surfaces to align the focal plane of the lens with the image plane of the sensor.

17. The lens mount of claim 12 further comprising an O-ring seal formed circumferentially around the lens body formed by placement of an O-ring within a scribed groove on the surface of the inner cavity of the lens holder.

18. The lens mount of claim 12 further comprising an electrical connector between the lens body and the lens holder, said electrical connector comprising circumferential strips of conductive material adhered to the lens body and spring loaded electrical connectors located on the surface of the inner cavity of the lens holder such that an electrical connection is completed when the lens body is inserted into the cavity of the lens holder.

19. The lens mount of claim 12 further comprising a mirror located in the optical axis of the lens and reflecting the focal plane of the lens onto the image plane of the sensor.

20. The lens mount of claim 19 where the mirror is not planar.