OPTICAL CENTERING AND ELECTRONIC TEST CONNECT DEVICE

Abstract: A component mount machine for mounting electronic circuit elements (110) has an optical system for recording the accurate position of a component (110), the system comprising a split mirror (113, 114). The mirrors are moved horizontally to a position underneath the component for reflecting pictures of portions of the component to cameras (102, 103). The two mirrors are located symmetrically and in the same angle to the bottom surface of the component (110) producing a small vertical extension of the optical mirror system which can withstand large acceleration forces when attached to a pickup head.

Description: OPTICAL CENTERING AND ELECTRONIC TEST CONNECT DEVICE FIELD OF THE INVENTION The present invention relates to automatic assembly machines and in particular to imaging devices used in such machines for obtaining information on the actual position of a component to be mounted. BACKGROUND OF THE INVENTION Assembly machines for surface mounted devices often use optical centering. Such machines pick up components from component feeders and place them on a circuit board. The position of the component in the feeder at the time of actual pick-up operation is not known with enough precision to permit an accurate placement on the circuit board. The component may for example be picked up from an embossed tape. The cavity in the tape is larger than the component, thus permitting the component to be anywhere within a certain area. The uncertainty of the component position within the cavity is larger than the position tolerance permitted on the board. Therefore a centering operation is necessary to reduce the uncertainty of the component position on the pickup nozzle after pick-up. Two methods are used. In the first method the component is moved by mechanical means to a position that is well centered around the axis of rotation of the pick-up nozzle, see e.g. our International Patent Application published under No. WO 86/03367. In the other method, the actual position of the component on the nozzle is maintained, but the position is measured by means of laser rays, image processing or other means. This method does not actually centre the component, but is anyway named "contactless centering". A placement of components using data of their position relative to a pick-up nozzle obtained from image processing is normally named "optical centering". Today, optical centering is mainly done by two methods. In one method, the pick-up head passes over a stationary camera with a speed that is low enough to permit a sharp recording of the image. In the other method, several pick-up heads are mounted on a rotary head. The head is rotated stepwise and is fixed in an angular position during a time slot. During this time slot one of the heads performs a pickup of a component and/or mounts a component on the circuit board. By placing a camera and a light source facing a fixed position that each of the pick-up nozzles that carries a component will pass, the offset of this component can be accurately measured. For high speed assembly machines comprising one or a few pick-up nozzles that only move vertically, the latter of the two above mentioned methods cannot be used. The first method, moving the component over a camera that has a fixed position, is commonly used for larger components, but puts restraints on the movements of the head, and the time period available from the time when a component passes over the camera to the time when the component is mounted on a circuit board is so short that the time required to make the image processing required for determination of the position of the component becomes critical. This method is especially unattractive for high speed mounting of small devices. There is therefore a need for a device permitting precise high speed image capture of components sitting on a nozzle that only moves vertically using devices that can be located o or secured to the pick-up head. Some such devices have recently been disclosed, for exampl in the European patent application EP-A1 0 449 481 and the U.S. patents US-A 5,172,46 and US-A 5,235,407. All these devices use a mirror that is either mounted on the pick-u nozzle shaft above the nozzle or is movable between two positions, the active position bein below the nozzle and the passive position being at the side of the active position below th nozzle in order to permit the nozzle to go down and place the component on the boar without hitting the mirror. In the latter case it is required that the nozzle is lifted higher tha normally (to permit the mirror to enter below the nozzle). In most cases it also makes th calculated position of the device sensitive to the actual position of the mirror and/or the actu height of the nozzle. A high speed mount head is subjected to large acceleration forces due to the horizont movements of the mount head from pick-up to the mounting position. Systems having one o a few nozzles require high accelerations to permit a short time movement from the positio where the component is picked up (above the feeder) to the position where the component i to be placed (above the circuit board). At a tact time of for example 0.6 second pe component mounted, the time period can be used as 0.1 second for nozzle up-dow movement during pickup, 0.2 second for mount head movements (in the order of 0.2 to 1. meters) from pick up to mount position, 0.1 second for nozzle up-down movement durin component mount and finally 0.2 second for mount head movements (in the order of 0.2 t 1.5 meters) from mount to pick-up position. Depending on the machine type, these moun head movements will be made in one or two dimensions in the horizontal plane. An optical system that is mounted on and follows a high speed mount head must permi highly accurate image data capture in an environment that is under large horizont acceleration forces. Due to the short time available it is also desirable that the image captur can start as early as possible after the pick-up operation. The image should preferably b taken having the optical axis of the image parallel to the vertical nozzle axis in order to avoi parallax problems and to reduce the effects of minor vertical movements of the pick up nozzl that may occur in the final phase of the lifting of the pick-up nozzle. If the optical system ha other moving part(s) beside the nozzle, the time available to move this part (these parts) i very short. It is therefore desirable that the image capture can start early, without having t wait for the movements of the nozzle and other parts to be terminated and find a fixed precis position relative to the vertical axis of the pick-up nozzle. Almost all the devices disclosed i the cited EP-A1 0 449 481, US-A 5,172,468 and US-A 5,235,407 use mirrors in such a wa that a movement in the direction of the normal movement of the mirror in its norma operation cycle will cause an equally large virtual movement of an image captured by th optical centering camera, thus causing an equally large mounting displacement when th position data from the camera is then used for calculating the actual position of th component on the nozzle. Another requirement of pick-and-place machines for high quality production environments is a capability of verifying the electric values of the passive components. This is preferably performed by means of test electrodes that touch the component when it rests on the pick-up nozzle. This will however add more mechanical details that must move in the space at and below the nozzle, thus requiring a higher lift of the nozzle and/or complex mechanical devices. SUMMARY OF THE INVENTION It is an object of the invention to provide an optical centering device that can be attached to the mount head of a mount machine and that permits a large field of view. It is another object of the invention to provide an optical centering device that can be attached to the mount head of a component mounting machine and that is compatible with an efficient mechanism for the electrical connection of passive components to an electric data verifier. It is another object of the invention to provide an optical centering device that has a low sensitivity to large acceleration forces in the horizontal plane. It is another object of the invention to provide an optical centering device that has a small vertical extension or permitting the centering operation to be made with a short movement of a component. It is another object of the invention to provide methods for optical reproduction that permit the construction of optical devices having small vertical extensions or permitting the centering operation to be made with a short movement of a component. It is another object of the invention to provide an optical centering device having specially designed illumination means permitting an efficient illumination of a component to be reproduced or depicted allowing a compact mechanical construction. The invention offers a solution to the problems discussed above and achieves the objects mentioned by providing an optical system that has one or several optical centering cameras on the mounting head, combined with two movable mirrors that can move from a passive position far from the pick-up nozzle path to an active position, where the two mirrors in some embodiments may effectively act as single mirror, the centre of which is in the path that the component will follow during mounting, or as mirrors providing two pictures which have a very small overlap. The mechanism moving the mirrors can also move electronic component verifying electrodes. The U.S. patent US-A 5,251,266 discloses an optical system for a placement apparatus using a split mirror. However, the two mirror parts are not moved from a passive to an active position but always capture pictures of a component obtained by reflecting light from the component by another mirror mounted around a pickup shaft. Thus, in a method of imaging or reproducing a component held by some nozzle in a component mounting device, for an "optical centering" or "contactless centering" of the component, the following steps are executed: moving the component to a first position suited for the imaging process, moving two mirrors from first passive positions apart from each other to second active or operative positions which are generally underneath or below the component, and taking a picture of the component as reflected in the two mirrors. In the second positions of the mirrors the image reflected by each one of the mirrors covers or is a reproduction of only a portion of the component, typically essentially half of the component or at least more than e.g. a third of the component, generally the bottom surface of the component. By this split mirror configuration the mirrors can also carry support surfaces for e.g. preliminary a mechanical centering of the component in one direction and/or electric connection surfaces for a testing of components. Also, for a suitable arrangement of the mirrors, the building height of the mirror device can be made smaller than with a mirror or mirror surface constructed in one single piece. The method can also be described as comprising the steps of moving the component and suitably configured mirror means in relation to each to first active positions, the operative positions for the reproduction step, illuminating the component with light in the first position thereof, and taking a picture of the component as reflected by the mirror means. Then light from the component is to be reflected by the mirror means in two light ray beams. The first positions of the component and the mirror means shall be such that each of the two light ray beams reflected by the mirror means forms an image of only a portion of the component, so that the picture taken will comprise two separate partial pictures. Each such partial picture should then be an image of only a portion of the component, where the mirrors are so arranged that the portions will form together or in combination a complete picture of the component, where there may be some, e.g. small overlap between the partial pictures. The method is used in a component assembly system or component mount machine which thus comprises image acquisition or reproduction means for generating an image of a component for a subsequent digital image processing of the image in order to find the actual position of the component in the position on the nozzle. The image acquisition means thus generally comprise illuminating means for issuing light towards the component, mirror means for reflecting light from the component to form a picture thereof, mechanical movement means for moving the mirror means and the component in relation to each other to suitable positions, and camera means for capturing a picture of the component as reflected in the mirror means. The mirror means comprise two separate mirrors and the movement means are to move the mirrors in relation to the component from first positions apart from each other to second positions suitable for a reproduction of the component. In the second positions an edge of one mirror may be located at or in the vicinity of, preferably in parallel to, an edge of the other mirror, to form a composite mirror having either a flat surface configuration like an ordinary flat mirror or an angled configuration where the cross-section of the composite mirror has the shape of an angle. The first, apart positions of the mirrors may be such that the component can be moved, generally in a vertical direction, in the space formed between the mirrors. The movement direction of the component is then preferably essentially perpendicular to a connection line between the mirrors in these positions and also to the movement directions of the mirrors. The positions of the mirrors can be always symmetrical, such that the movement axis of a nozzle holding the component will pass well centrally or centered between the mirrors, in all positions of the mirrors. The movement directions of the two mirrors may thus preferably be along essentially the same horizontal line but in opposite directions. In the second positions of the mirrors, as has been described above, the image reflected by each one of the mirrors will advantageously cover or correspond to only a portion of the component, the two portions then preferably covering in combination all of the component, that is all of the component as viewed in a definite direction, e.g. as viewed towards the bottom side of the component. Thus every partial image covers essentially different portions of the component surface. For obtaining a compact construction, the illuminating means may comprise light emitting elements located at edges of each mirror for emitting light particularly in directions away from the reflective surfaces of the mirrors, so that essentially no emitted light rays will hit directly the reflective surfaces. When a remote location of the illuminating means is desired it may comprise a light source emitting light in a preferred direction and a semitransparent mirror, so that light from the light is reflected by the semitransparent mirror and light reflected by the two mirrors of the mirrors means will pass straight through the semitransparent mirror to hit the camera means, where of course the arrangement can be inverted, to allow the light from the light source to pass straight through the semitransparent mirror and the light beam forming the image to be deflected. The two mirrors of the mirror means are always essentially flat and the position thereof can be described as they are located, in the operative position of the mirror means, with reflecting surfaces of the two mirrors in a first, same angle to a bottom side of the component of which a picture is taken and then of course both in a second, same angle to a movement direction of the component, along which it is moved to its first position. The two separate mirrors are each one advantageously carried by a separate wagon, where the wagons also may carry electrical contact means for contacting, in positions near the second positions of the mirror means and the component, electrical terminals of the component. The movement means may then be arranged to move the wagons, during a movement from the positions apart from each other to the operative positions, symmetrically towards each other, in opposite directions. BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the invention will now be described with reference to the accompanying figures: - Figure la is a side view of the optical paths when a component is viewed by two centering cameras by means of a high speed mirror pair, - Figure lb is another view of the optical paths for one of the two cameras, - Figure 2a is a sectional view of the camera and mirrors and some mechanical devices for mirror movement in the image capture position, - Figure 2b is a top view corresponding to that of figure 2a also showing illumination and driving means, - Figure 3a is a top view similar to that of figure 2b in the component movement position, - Figure 3b is a sectional view similar to that of figure 2a but corresponding to opened position of figure 3a, - Figure 4a is a sectional view of the mirror carrying wagons having additional mechanical means for electrodes in a position permitting the connection of the picked up component to an electronic verifier, - Figure 4b is a sectional view similar to that of figure 4a of the same component during the optical centering phase, - Figure 4c is a sectional view similar to the views of figures 4a and 4b of the same component during vertical movement, - Figure 5 is a schematic side view of an optical centering device where the two mirrors in the active positions act as one single flat mirror, - Figure 6 is a schematic side view illustrating the optical paths for a system similar to that of figure la but having larger focal distances, - Figure 7 is a perspective view of a component assembly device. DETAILED DESCRIPTION Figures la and lb are side views of the optically relevant part of a mount head of a component mount machine, see the description of figure 7 hereinafter. A component 101 is kept in its position as illustrated by a pick-up shaft and an associated nozzle, see figure 3b. Light from mainly the bottom side of the component is reflected by two obliquely positioned mirrors 113, 114 to hit cameras which are shown schematically at 102 and 103 and have light entrance openings as illustrated comprising suitable optics, if needed. The cameras should preferably offer a large field of view and a high resolution. The resolution required is some 1000x 1000 pixels. With presently available cameras such large resolutions are costly, and therefore, using present camera technology, a set of two 1/3 inch CCD-cameras can be used. One such camera could have a field of view of for example 40.5x54 mm. By placing two such cameras side by side, they could cover an area of 54 81 mm. In the embodiment shown, the utilized field of view is basically square, thus permitting a complete view of components up to some 54x54 mm in one exposure. The total field of view is shown in figure lb as dimension 104 by dimension 105. The field of the two cameras overlap so that both cameras cover the section shown at 106 in figure lb. The area seen from camera 102 covers the area from 107 to 108, the other camera 103 covering the span from points 109 - 110 to points 111 - 112. Commonly available camera chips transfer data starting at the top horizontal line. By a suitable orientation of the CCD camera chips, the image information could thus be accessed starting with the two lines in the centre of the combined field of view. The camera 103 should for example be so oriented that the data corresponding to the line 109 - 110 is transmitted first and the data corresponding to line 111 - 112 is transmitted last. Thereby the time required to wait for obtaining data regarding small components in the centre of the image can be substantially reduced. In the embodiment shown the overlapping range 106 is small, e.g. less than 5 % of the total area of a camera chip. With the aspect ratio of presently common camera chips, this means that the last part of the image surface of the camera chip will not be used. The mirrors 113 and 114 are basically flat mirrors and are located, in the closed position as illustrated in figures la and lb, in a symmetrical fashion in an angle to the generally flat bottom surface of the component, and in an angle also to the movement direction of the component, the Z-direction which is substantially perpendicular to the component bottom surface. The angle to the bottom surface is as illustrated about 30° but can generally take any angle of the range 15 - 45° or even larger angles, considering suitable mounting places of the cameras 102, 103 and the illumination directions, for avoiding light to be emitted directly into the camera entrance openings. The mirrors 113 and 114 have a rectangular shape. As can be seen from the optical paths as illustrated in figure lb, the mirrors could be made smaller by eliminating the mirror outside a line from reflection area 115 of the rays from point 111 to the mirror corner that reflects the rays from point 109. Figures 2a to 3b are views showing parts required for moving the mirrors 113 and 114 and for illuminating the component 101. The figures 2a and 2b are two views of the device in the image capturing position and the figures 3a and 3b are views of the device in a fully open position suitable for lifting or lowering large components. In figure 2a the component 101, the cameras 102 and 103 and the mirrors 113 and 114 are shown in the same position as shown in figures la and lb. The oblique mirror 113 is carried by a wagon 201 that runs along two parallel linear bearing shafts 202 and 203 using ball slides 204 and 205. A motor indicated by the dashed line 206 can move the wagon 201 through two steel bands 207 and 208 which at first ends are secured to an arm 209 that is integrated with the wagon 201. The two bands run around a pulley 210 secured to the shaft of the motor and the other ends of the bands are secured to an arm 211 that is an integral part of a wagon 212 that carries the other mirror 114. The thickness of the steel bands 207 and 208 is highly exaggerated in the figure; if drawn in a correct scale they would be invisible in the figure. The second wagon 212 uses ball slides 214 and 215 to run along the same linear bearing shafts 202 and 203 as is used by wagon 201. The illumination is arranged by LEDs 213 arranged along the exterior edges of the flat, rectangular mirrors 113 and 114, of course not at the edges where the mirrors connect to each other. Any lateral movement of the mirrors 113 and 114 will cause an almost equally large virtual movement of an image captured by the optical centering camera, thus causing an almost equally large error in a calculated position or in the shape of the component, when the picture data from the camera is used for calculating the position of the component 101. The basic design of the mechanism of figure 2b can however easily be made so that the position of the mirrors when closed together as shown in figure 2b is very stiffly and definitely defined. The task for the servo motor 206 controlling the movement of the two mirror carrying wagons 201 and 212 is in this position very simple: it should only apply a torque directed to press the two wagons together. The embodiment as described has therefore a very low sensitivity to servo displacement due to large horizontal accelerations and thus, it can be secured to the pick-up head, see figure 7, of the mount machine without having the movements of the head interfering with the operation of the image acquisition system. The mirror position servo is basically pressing against a mechanical stop. The accelerations of the head affect the two horizontal axes, not the vertical one, and the vertical Z-axis is therefore basically unaffected. Small vertical movements of the Z-axis will only marginally affect the data obtained from the camera image. Vertical movements cause a virtual size scale error in the image taken by the cameras 102 and 103 or 503, see fig. 5 described hereinafter; the data concerning the horizontal centre position of the component 101 on the nozzle 102, see figure 3b, and its angular position will be only marginally affected by a small vertical movement of the Z-axis. From figure 2a it also obvious that the device can operate satisfactorily with a very limited vertical lifting movement, that is the extension of the mirror system in vertical direction is small, this being achieved primarily by the split mirror configuration and also by the preferred angle of about 30° of the mirrors. The views of figures 3a and 3b show the two mirror carrying wagons 201 and 212 in their fully opened position. The component 101 is shown at the end of a movement down to the circuit board 301. The component is retained by a vacuum nozzle 302 that is moved vertically along an axis 303 and that can be rotated around the same axis 303. Figure 4a is a side view of the mirror wagons like 201 and 212 of figures 2a - 3b. The wagons shown have mechanical devices for electrodes. These electrodes permit the connection of an electronic verifier to a component. In the normal component assembly sequence, the component is first picked up by moving the mirror-electrode units 407 and 408 when they are located apart from each other, as shown in figure 4c so that the Z-shaft and its nozzle 402 can go down to reach a level where the components are available in the feeders, compare figure 7. The rotation of the nozzle 402 around the axis 409 can be controlled by a motor. The bearings, motors etc. used to vertically move and turn the nozzle 402 along and around the vertical axis 409 are not shown. To permit a check of the electrical value of the component 401, the component 401 is first picked up. It is then lifted to the position shown in figure 4a. During the lift operation it is, if required, rotated so that its electrical connection surfaces face the electrodes 403 and 404. These are then closed together so that the electrodes 403 and 404 can establish contact to the connection surfaces of the component 401. (This will in addition cause a mechanical centering of the component 401 in one dimension relative to the nozzle 402.) The component 401, for example an 0805 resistor, is thereby connected to an electronic test device, not shown, that can compare the expected value of the component to the real value as measured. The electrodes are assembled on a small vertical platform 405. The electrical connections to the electrodes are made through a connector 406. This permits an easy exchange of the electrodes. By using different vertical positions different electrode sets can be used. After the electronic test has been successfully performed, the mirror-wagons 407 and 408 are moved apart so that the Z-shaft can go up to reach the level shown in figure 4b. The mirror-wagons 407 and 408 are then moved together to create the optical path shown in figures la - lb and 4b. The captured image permits the position of the components 401 position on the nozzle 402 to be calculated and a correct placement on the circuit board to be performed using control principles for optical centering which are already well known. Figure 5 is a schematic side view illustrating an optical centering device where the two mirrors act as one single flat mirror in the active positions thereof. This will give a larger vertical extension of the mirror system than that of the embodiment described above having mirrors which are located with their reflective surfaces in a substantial angle to each other. In figure 5 only the components are shown that determine the optical paths. The mirror pair 501 and 502 are movable in the left-right direction, for example using mirror and electrode carrying wagon pairs like 201 and 212 of figures 1 - 4. The mechanical devices for moving the mirrors 501 and 502 can generally be designed as has been described herein for the first embodiment. The camera 503 is placed behind a double prism 504 acting as a semitransparent mirror or beam splitter. The mirror permits light from a source 505 to illuminate the component 506. The use of two half mirrors 501 and 502 that act as one common mirror can of course be used together with other illumination arrangements. Figure 6 is a schematic side view of the optical paths for a system similar to that of figures la, lb but having larger focal distances. Items in figure 6 denoted by numbers in the 100-series are similar to those of figure la. Since the focal distance is larger, there is more space between the camera lenses 102 and 103 and the component 101 and mirror pair 113 - 114. Presently common camera chips having a resolution of 752x582 pixels, if used in the embodiment of figures la - 3b and 6, will permit a 752x752 pixel resolution for a square field of view indicated by the distance 107 - 111 in figure 6. The square field of view will however not utilize the whole camera chip; a rectangular field of view from points 601 to 602 can be obtained if the mirrors 113 and 114 are enlarged to include the optical paths indicated by 603 and 604. The two embodiments shown permits an accurate optical centering of large components using presently available camera chips. Presently emerging camera chips having a square field of view of 1024 x 1024 pixel will, if used in the embodiment of figure 5, permit a 1024 x 1024 pixel resolution for a square field of view. In the cases where the resolutions of the cameras 102 - 103 or 503 are too low, a chassis mounted camera, not shown, could be used. As components requiring such very high resolution are low-frequent, this camera can have a narrow field of view and handle larger components by taking several images in the prior art manner. In figure 7 a component assembly or pick-and-place machine is illustrated in a perspective view showing the general configuration of such a machine. The wagon 701 is movable along the horizontal bar 703 to different locations, such as above magazine sites 705 intended to hold component feeders, which are movable in a horizontal direction perpendicular to the guide bar 703 and above a printed circuit board 707 retained on a slide, also movable in the same direction as the magazine sites 705. The wagon 701 carries a pickup unit 709, at the lower side of which a vacuum nozzle such as 302, 402 is located which can be moved vertically and rotated about a vertical axis. The nozzle can pass through a frame 711 carrying the optical devices for an optical centering of a component hold by the nozzle, for instance the obliquely positioned mirrors of figures 2a - 4c. Although the present invention has been fully described by way of examples with reference to the accompanying drawings, it is to be noted here that various changes and modifications will be apparent to those skilled in the art. The illumination of the components to be studied can for example be made in several ways already used in the industry for optical centering purposes, even if in many such cases more space should be arranged by increasing the focal distance from camera(s) as indicated in figure 6. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as included therein.

Claims: CLAIMS 1. A method of imaging a component in a component mounting device, characterized by the steps of - moving the component to a first position, - moving two mirrors from first positions to second positions, - taking a picture of the component as reflected in the two mirrors, wherein the second positions of the mirrors are such that the image reflected by each one of the mirrors covers only a portion of the component, in particular essentially half of the component. 2. A method of imaging a component in a component mounting device comprising the steps of - moving the component and mirror means in relation to each to first positions, - illuminating the component with light in the first position thereof, - taking a picture of the component as reflected by the mirror means, characterized in that light from the component is reflected by the mirror means in two light ray beams, and that the first positions of the component and the mirror means are such that each of the two light ray beams reflected by the mirror means forms an image of only a portion of the component, in particular essentially half of the component, whereby the picture taken will comprise two partial pictures, each one of only a portion of the component, the portions forming together a complete picture of the component, in particular with a small overlap. 3. A component assembly system comprising image acquisition means for generating an image of a component, the image acquisition means comprising: - illuminating means for issuing light towards the component, - mirror means for reflecting light from the component to form a picture thereof, - means for moving the mirror means and the component in relation to each other, - camera means for capturing a picture of the component as reflected in the mirror means, characterized in that the mirror means comprise two separate mirrors, the moving means being arranged to move the mirrors in relation to the component from first positions apart from each other to second positions, in particular so that an edge of one mirror is located at or in the vicinity of, preferably in parallel to, an edge of the other mirror. 4. A system according to claim 3, characterized in that the first positions of the mirrors are such that the component can be moved by the moving means in a space between the mirrors, in particular in a direction essentially perpendicular to a connection line between the mirrors in these positions. 5. A system according to one of claims 3 - 4, characterized in that the moving means are arranged so that the movement directions of the two mirrors are along essentially the same line but in opposite directions. 6. A system according to one of claims 3 - 5, characterized in that the second position of the mirrors are such that the image reflected by each one of the mirrors covers only portion of the component, in particular essentially half of the component. 7. A system according to one of claims 3 - 6, characterized in that the second position of the mirrors are such that the image reflected by one of the mirrors covers only a portion o the component and the image reflected by the other one of the mirrors covers another portio of the component, these two portions covering in combination the whole component, i particular with only a small overlap of the images formed. 8. A system according to one of claims 3 - 7, characterized in that the illuminatin means comprise light emitting elements located at edges of each mirror for emitting ligh particularly in directions away from reflective surfaces, so that essentially no emitted ligh rays hit directly the reflective surfaces. 9. A system according to one of claims 3 - 8, characterized in that the illuminatin means comprise a light source emitting light in a preferred direction and a semitransparent mirror, light from the light being reflected by the semitransparent mirror and light reflected by the two mirrors of the mirrors means passing straight through the semitransparent mirro to hit the camera means or vice versa. 10. A system according to one of claims 3 - 9, characterized in that the camera mean comprise two separate cameras, each one being arranged for capturing an image reflected by one of the mirrors. 11. A component assembly system comprising an image acquisition means fo generating an image of a component, the image acquisition means comprising: - a mirror means - means for moving the component and the mirror means in relation to each other to first positions, - means for illuminating the component with light in the first position thereof, so tha light coming directly from the component is reflected by the mirror means to form a pictur thereof, - camera means for capturing a picture of the component as reflected by the mirror means, characterized in that the mirror means are arranged to reflect the light coming from th component in two light ray beams, the first positions of the component and the mirror means being such that each of the two light ray beams reflected by the mirror means forms a picture of only a portion of the component, in particular essentially half of the component, whereb the picture taken will comprise two partial pictures, each one of only a portion of th component, the portions forming together a complete picture of the component, in particular with a small overlap. 12. A system according to claim 11, characterized in that the mirror means comprise two separate mirrors, the two mirrors being essentially flat and located, in the first position of the mirror means, with reflecting surfaces thereof in a first, same angle to a bottom side of the component of which a picture is taken and/or both in a second, same angle to a movement direction of the component, along which it is moved to its first position. 13. A system according to one of claims 11 - 12, characterized in that the mirror means comprise two separate mirrors, the two mirrors being essentially flat and located, in the first position of the mirror means, with reflecting surfaces thereof in essentially the same geometric plane. 14. A system according to one of claims 11 - 13, characterized in that the mirror means comprise two separate mirrors, each one carried by a separate wagon, the wagons also carrying electrical contact means for contacting, in second positions of the mirror means and the component, electrical terminals of the component. 15. A component assembly system comprising image acquisition means for generating an image of a component, the image acquisition means comprising: - illuminating means for issuing light towards the component, - mirror means for reflecting light from the component to form a picture thereof, - means for moving the mirror means and the component in relation to each other, - camera means for capturing a picture of the component as reflected in the mirror means, characterized in that the mirror means comprise two separate parts, each one carried by a separate wagon, the moving means being arranged to move the wagons in relation to the component from first positions apart from each other to second positions, where an image of the component can be acquired, the wagons also carrying electrical contact means for contacting, in particular in third positions of the wagons, located between the first and second positions, electrical terminals of the component. 16. A system according to claim 15, characterized in that the moving means are arranged to move the wagons, during a movement from the first positions to the second or third positions, symmetrically towards each other, in opposite directions. 17. A system according to one of claims 15 - 16, characterized in that the moving means are arranged to move the wagons, during a movement from the first positions to the second or third positions, in directions perpendicular to a movement direction of the component when passing between the wagons. 18. A component assembly system comprising an image acquisition means for generating an image of a component, the image acquisition means comprising: - a mirror, - means for moving the component and the mirror in relation to each other to first positions, - means for illuminating the component with light in the first position thereof, so that light coming from the component is reflected by the mirror to form a picture thereof, - camera means for capturing a picture of the component as reflected by the mirror, characterized in that the illuminating means comprise light emitting elements located at edges of the mirror for emitting light particularly in directions away from reflective surfaces, so that essentially no emitted light rays hit directly the reflective surfaces. 19. A system according to claim 18, characterized in that the light emitting means comprise a multitude of individual light emitting elements located in rows at and in parallel to exterior edges of the mirror. 20. A system according to one of claims 18 - 19, characterized in that the light emitting means are arranged to emit light from lines located at and in parallel to exterior edges of the mirror. 21. A component assembly system comprising an image acquisition means for generating an image of a component, the image acquisition means comprising: - a mirror, - means for moving the component and the mirror in relation to each other to first positions, - means for illuminating the component with light in the first position thereof, so that light coming from the component is reflected by the mirror to form a picture thereof, - camera means for capturing a picture of the component as reflected by the mirror, characterized in that the illuminating means comprise a light source emitting light in a preferred direction and a semitransparent mirror, light from the light being reflected by the semitransparent mirror and light reflected by the mirror passing straight through the semitransparent mirror to hit the camera means or vice versa. 22. A system according to claim 21, characterized in that the semitransparent mirror comprises a double prism.

Inventors: STRIDSBERG LENNART, STRIDSBERG, LENNART
Applicants: MYDATA AUTOMATION AB, STRIDSBERG LENNART, STRIDSBERG, LENNART
Application year: 1995
Main classification: H05K13
IPC codes: G01B11, H05K13