Abstract:
A computerized control and display system for a stereo microscope is disclosed. The objective lens is selected for a minimum and maximum magnification range and then two sets of movable lenses within the stereo module are positioned through computer control to achieve a precisely desired magnification. In the preferred embodiment, a lookup table is used to smoothly select the proper position of the two movable lenses in relationship to one another as the magnification is either increased or decreased. A stereoscopic image is transmitted by cameras to a computer screen with the use of a wireless eyewear/shutter system cycling at 120 cycles per second for viewing.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to the field of optics. More specifically, it relates to the field of microscopy. Even more specifically, it relates to the field of stereoscopic microscopy. Even more specifically, it relates to the field of digitally controlled stereo microscopy, wherein the image is transmitted to a computer screen and the magnication, zoom, and focus is controlled through a software based interface. 
     2. Description of the Prior Art 
     One of the major problems inherent in the type of microscopy wherein a fixed objective in combination with two movable lenses or lens sets are used to zoom and focus the image on the stage is that the manual controls for these devices are extremely difficult to manufacture and are very delicate, adding to both the cost of the device and subsequent breakdowns and repairs. This is because the distances between the movable lenses and the stationary lenses that they cooperate with each other to move between low and high zoom are not linear. As the user zooms in on the image through the fixed objective, from low to high, a graphed comparison measuring distance between the lower movable lens or lens set and its respective lower stationary lens or lens set and the corresponding movable and stationary upper lens or lens set become less and less iear, especially at higher magnifications Thus eccentric threading, cams, and the like must be used to allow the user to precisely control the zoom while focusing the image. Additionally, the present invention addresses the problem that in existing microscopy systems that use this movable lens pair or pairs system to zoom in and out and focus on the resultant image, remote control is very difficult and slow, if not impossible. The present invention, by supplying a smooth, computer controlled zoom and focus system over the range provided by the objective makes such tasks at a remote location simple. Combined with a stage movable on an X-Y axis under the same computer control along with a vertical control of the optics module, microscopic level inspections of silicon wafers, biological subjects, metallurgical samples, or other similar objects may be accomplished at the remote location Simultaneous movement of both lenses or lens sets is provided by a software routine that uses a lookup table or the like to set the precise axial distance between the controlled optic stages to provide a focused image at a desired magnification or zoom level In the preferred embodiment, video cameras transfer the image to a computer screen where the user is also controlling the magnification and zoom. Additionally, using multiplexed, “frame sequenced” images along with a wireless stereoscopic switching glasses cycling at 120 times per second, a live, high definition stereoscopic image is made available to the user. Thus, the instant invention provides a valuable tool for applications such as telemedicine, remote operation and/or inspection, defect and failure analysis, quality control, and learning at a distance. Additionally, people with disabilities using special computer controls, can do valuable work that they were previously unable to do. 
     During a search at the U.S. Patent and Trademark Office, a number of relevant patents were uncovered and they will be discussed below. 
     First is U.S. Pat. No. 3,818,125 issued on Jun. 18, 1974 to James F. Butterfield. This discloses a stereo television microscope where the two slightly different images are alternated and the viewer, looking through a stereo mask, perceives a three dimensional image. This is completely unlike the present invention in that no teaching of the software controlled positional settings of the movable lens sets is taught. 
     U.S. Pat. No. 3,873,182 issued on Mar. 25, 1975 to Hidehio Furuhasi discloses a magfication varying device in an optical instrument. This is also dissimilar from the present invention in that no teaching of the simultaneously changing distance between a pair of movable lens sets is set out. 
     In U.S. Pat. No. 4,195,903 issued to Suminosuke Kawase et al. on Apr. 1, 1980 there is disclosed a binocular microscope with lenses rotatable in the plane of the optical axes. Unlike the present invention, axial distance between sets of lens pairs in unchanged. 
     An automatic focusing device is disclosed in U.S. Pat. No. 4,447,717 issued to Massao Nohda on May 8, 1984. This is an automatic focusing device that uses a position sensor on the sample, unlike the present invention. 
     In U.S. Pat. No. 4,653,878 issued to Kanae Nakasato on Mar. 31, 1987 there is disclosed a microscope equipped with a device for driving the revolver and the stage. This is accomplished with a photosensor, unlike the present invention. 
     U.S. Pat. No. 4,705,367 issued on Nov. 10, 1987 to Alan C. Eckbreth et al. discloses an optical system having a variable focal length. Unlike the present invention, there is no teaching of the lens sets or the look-up table. 
     In U.S. Pat. No. 4,744,642 issued to Makoto Yoshinaga et al. on May 17, 1987 there is disclosed a microscope. In this system, the objective is movable in relation to the sample. This is clearly unlike the present invention. 
     In U.S. Pat. No. 5,054,896 issued on Oct. 8, 1991 to H. Jay Margolis there is disclosed a continuously focusable microscope. There are three lenses or sets of lens, which is dissimilar from the instant invention. 
     U.S. Pat. No. 5,307,202 issued to Ronald J. Martino et al on Apr. 26, 1994 discloses a copy port wherein digital stored images may be manpulated, stored, or viewed through eyepieces. No teaching of the look-up table for the automatic setting of focal distance between the lenses is seen. 
     U.S. Pat. No. 5,394,267 issued on Feb. 28, 1995 to Toyo Hanzawa discloses a stereomicroscope. Unlike the present invention, this invention utilizes eyepieces and a single objective lens. 
     An accessory for a stereo microscope is disclosed in U.S. Pat. No. 5,537,248 issued to Ulrich Sander on Jul. 16, 1996. This invention is directed at pivotal optical elements, which is clearly dissimilar from the present invention. 
     U.S. Pat. No. 5,539,572 issued on Jul. 23, 1996 to Gary Greenberg et al. discloses a microscopic Iumiation and viewing system Unlike the present invention, there is no teaching of the paired fixed and movable lenses or lens sets. 
     U.S. Pat. No. 5,661,598 issued on Aug. 26, 1997 to Ken Tomioka discloses a optical instrument with a single eyepiece unit. This is clearly unlike the construction of the instant invention. 
     U.S. Pat. No. 5,663,834 issued to Noburu Koizumi on Sep. 2, 1997 discloses a zoom lens system dissimilar from the present invention in that it has a single fixed ens group and a pair of movable lens groups. 
     U.S. Pat. No. 5,668,660 issued on Sep. 16, 1997 to Gary D. Hunt discloses a microscope with a plural zoom lens assembly. Unlike the present invention, this includes a selectively movable prism in the optical path. 
     An electrically driven microscope is disclosed in U.S. Pat. No. 5,706,127 issued to Hiroko Saito et al. on Jan. 6, 1998. Unlike the present invention, there is no teaching of the paired fixed and movable lenses or lens sets of the instant invention. 
     U.S. Pat. No. 5,729,382 issued on Mar. 17, 1998 to Kazuo Morita et al. discloses a stereoscopic microscope. As with many of the other patents discussed above, there is no teaching of the look-up table and the automatic focal length setting. 
     Another patent of interest is U.S. Pat. No. 5,825,532 issued on Oct. 20, 1998 to Ryo Mochizuki et al. This discloses a microscopic system integrated with a wide screen television. None of the control features of the instant invention are taught. 
     In U.S. Pat. No. 5,825,535 issued to Klaus Biber et al. there is shown a pancratic magnification system that is unlike the present invention in that there is no teaching of the computer controlled lens set adjustments. 
     Lastly, U.S. Pat. No. 5,949,574 issued on Sep. 7, 1999 to Hans-Georg Kapitza discloses a computer supported video microscope. Unlike the present invention, there is no teaching of the paired fixed and movable lenses or lens sets. 
     Thus, while the foregoing overview of prior art indicates it to be well known to digitally control microscopes and to use similar types of lens arrangements it is not seen that the novel control system and construction of the present invention is taught either singly or in combination by any of the art of record. 
     SUMMARY OF THE INVENTION 
     To achieve the foregoing and other advantages, the present invention, briefly described, provides a computerized control and display system for a stereo microscope. The objective lens is selected for a minimum and maximum magnification range and then two sets of movable lenses within the stereo module are positioned through computer control to achieve a precisely desired magnification. In the preferred embodiment, a lookup table is used to smoothly select the proper position of the two movable lens sets in relationship to one another as the magnification is either increased or decreased. A stereoscopic image is transmitted by cameras to a computer screen with the use of a wireless eyewear/shutter system cycling at 120 cycles per second. 
     Thus it is a principal object of the invention to provide a unique, computer controlled microscopy system wherein the zoom and focus control within the range of a chosen objective lens is predetermined and controlled by an algorithm. 
     An additional object of the invention to provide a computer controlled stereo microscopy system wherein the magnification and focus is precisely controlled to allow hands free usage of the machine. 
     Another object of the invention is to provide a computer controlled stereo microscopy system that obviates the need for mechanical linkages that are both difficult to machine and that have a tendency to malfunction due to the delicacy and fine tolerances required. 
     Yet another object of the invention is to provide a computer controlled stereo microscopy system that allows remote viewing for three dimensional microscopic examination of parts in dangerous environments. 
     Still yet another object of the invention is to provide a computer controlled stereo microscopy system that provides for smooth magnification zoom and automatic proportional focusing by using a lookup table for positioning of the movable lens sets of the invention in relation to one another. 
     Still yet another object of the invention is to provide a computer controlled stereo microscopy system that allows disabled people to easily operate the machine. 
     Still yet another object of the invention is to provide a computer controlled stereo microscopy system that does away with the necessity to stoop over eyepieces or the like to examine a sample. 
     These together with still other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be better understood and the above objects as well as objects other than those set forth above will become more apparent after a study of the following detailed description thereof Such description makes reference to the annexed drawings wherein: 
     FIG. 1 is a perspective view of the stereo module of the present invention mounted on the vertical and horizontal X-Y axis control assemblies with the front panel removed to show the fixed and movable lens sets disposed within. 
     FIG. 2 is a front plan view of the interior of the stereo module showing the disposition of the fixed and movable lens sets of the instant embodiment in a low magnification configuration. 
     FIG. 3 is a front plan view of the interior of the stereo module showing the disposition of the fixed and movable lens sets of the instant embodiment in a high magnification configuration. 
     FIG. 4 is a rough graphical depiction of the distance in millimeters between the bottom fixed/bottom moveable and top fixed/top moveable lens sets and the non-linear relation between the two as magnification increases in the instant embodiment of the invention. 
     FIG. 5 is a representational example of the computer screen control interface for the instant embodiment of the invention. 
     FIG. 6 is an exploded view of the five lens sets apart from their carriages in the instant embodiment of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Turning first to FIG. 1, the invention in general is indicated at  10 . The computer controlled microscopy stereo module  12  is located mounted on a top assembly  14 . Through means of a stepper motor driving an endless threaded screw (not shown), the stereo module  12  is movable up and down the substantially flat front face  16  of the top assembly  14  with great accuracy. It should be understood that the top assembly  14  is also located on a base assembly  18  and, through another pair of stepper motors driving endless threaded screws perpendicular to one another, X-Y control is also provided for. Thus, the stereo module  12  can be specifically located at a predetermined height and at a predetermined location over a sample or specimen. 
     The overall internal details of stereo module  12  will now be detailed. In the instant embodiment there are five sets of lenses, not including the objective  100 , which will be discussed separately. All five of these sets are seen in FIG. 6, whereas in FIGS. 2 and 3, the camera relay lens set  20  and their corresponding first surface mirrors M are not shown. The details of the stereo module  12  lens assemblies can be best studied referring to FIGS. 1,  2 , and  3 . In the embodiment described herein, the lower pair of lens sets  22 ,  24  are used to choose the magnification and the upper pair of lens sets  26 ,  28  are used to focus. It should be understood, however, that this arrangement could easily be reversed. The lowest lens set is located on lower fixed bracket  30 . The set above that is located on the lower movable bracket  32 . Turning to FIGS. 2 and 3, it can be seen that lower movable bracket rides along rails  34  set along the inside of the stereo module  12 . Stepper motors (not shown) rotate the endless threaded screws  36 ,  38  to move either the lower movable bracket  32  or the upper movable bracket  40  a predetermined distance from their respective fixed brackets  30 ,  42  as will be discussed further below. In the embodiment shown in the drawings, one of the movable brackets is driven by one endless threaded screw, say the lower movable bracket  32  by endless threaded screw  36  and the upper movable bracket  40  by endless threaded screw  38 . By rotating the endless threaded screws  36 ,  38  in small discrete steps, precise control over the distances between the respective fixed and movable brackets can be obtained. 
     It should be noted at this point that though lens sets are being discussed, the inventive concept behind the instant invention could easily be applied to four separate single lenses in the same manner, controlling the spacing between the respective movable and fixed brackets that carry the specific lens in the same computer controlled method. 
     The types of corresponding lenses that cooperate with each other to provide the desired magnification are well known to those in the art and form no inventive part of the invention. 
     Turning to FIGS. 2 and 3, in the embodiment described herein, FIG. 2 represents the spacing of the lens sets in relation to one another when the magnification desired by the user is low. FIG. 3 represents the spacing of the lens sets when the magnification desired by the user is high Depending on the objective selected by the user, this can provide magnification in ranges from between approximately 3.75×to 258×. 
     Looking at FIG. 4, a critical aspect of the invention is shown The distance between the lower fixed and lower movable and the upper fixed and upper movable lens sets (or single lens) is not proportional. This is why, in the existing art that is manually controlled, such difficult machining and constrution is seen. As both cooperating upper and lower pairs of lens sets move from lower to higher magnification, the distance between the movable and fixed lower set, for example, levels off at a certain point, indicated generally at  44 . The top pairing of lens sets distances, however, increases slightly in its slope, as indicated at  46 . These non-linear relationships make devices using hand controlled mechanical magnification adjustment and focus extremely expensive, difficult to manufacture, maintain, and repair. The present invention, by using computer controls to set the known required distance relation for a set magnification and focus, eliminates these mechanical contortions, and also allows for more comfortable viewing. 
     For each specific lens set or type of lens that is being used in a set, The first, lower, movable set is stepped by its motor to a desired magnification Then, the second, upper movable set is moved by its motor to bring the image into focus. The computer then saves these discrete stepping distances in a lookup table and whenever the specific magnification in combination with that specific lens set is called for by a user, the upper and lower movable lens sets  40 ,  32  are moved into the correct position by their respective stepper motors. For each group of lens sets that the user has or wishes to have, a separate lookup table is either provided or created by the user to position the movable brackets carrying the lens sets at their correct distances from the respective fixed brackets. 
     Turning now to FIGS. 1 and 5, the cameras that relay the images to the computer (discussed below) will now be briefly addressed. In the embodiment described herein, these cameras  48  are Panasonic GP KR 222s. These receive the images through camera relay lenses  20 . Each image is then reflected through a pair of right angle prisms or first surface mirrors as indicated at  50  and  52 . Any combination of these optical devices could be used, as their qualities, along with the advantages and disadvantages of using them in different circumstances, are known to those skilled in the art. 
     The discussion now turns to the computer interface and user control of the apparatus. In FIG. 6 there is a representation of an interface such as would be used with the WINDOWS® operating system and its common graphical interface. The area designated as  54  would be the area in which the view of the work area in focus would be displayed. On the right hand side are the controls for the magnification, focus, and staging controls. At  56  there is the designation of the position of the cursor  58 . At  60  and  62  there are the designation of the X-Y position of the staging. Controls for the staging are indicated at  64 . Coarse and fine focus controls are indicated at  66  and  68 , respectively. The zoom control is indicated at  70 . This type of interface is standard in the way that the mouse reacts with the GUI (Graphical User Interface). It should be understood that the interface as thus described could easily be adapted to operating systems other than the one mentioned above. LINUX or any of the MACINTOSH OS would be equally compatible as the interface itself would preferably be written in some offshoot of the “C” language or other multi-platform and operating system language. 
     The connection between the operating computer C and the instant invention  10  would be accomplished through a standard bus port, a SCSI connection or other type of connection as indicated at  72 . 
     Another feature of the invention is that it provides a unique interface that allows for real-time 3-dimensional interface combined with the Crystal Eyes wireless eyewear system The right and left views are shuttled through at 60 frames/second (120 fields/second) and the Crystal Eyes eyewear, using LCD technology, shutter the frame on the opposite, eye to simulate a three-dimensional view. 
     In the description above, it should be noted that all of the stepper motors used are commonly available and their control and use are known to skilled practitioners.