JPS62156507A - Optical inspection device inspecting surface of three-dimensional body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a programmable apparatus for automatic optical inspection of three-dimensional surfaces to detect defects.

One aspect of the invention is an optical/mechanical device that can provide images of various depths along the inspection optical axis independently of the illumination optical path and without changing the magnification of the image formed. It is related to.

Another aspect of the apparatus of the invention is to move the television camera to the X of the image plane.
This relates to a table for moving along the Y-axis and positioning it precisely.

Another aspect of the apparatus of the invention is to digitize, synchronize, remove, DC regenerate, gain, offset control and anti-aliasing an analog video signal.
The present invention relates to a device that performs anti-alias filtsring.

Yet another aspect of the apparatus of the present invention is to use two blanking signals to implement a window, and a portion of a tilted video RAM to input and output data while maintaining a common timing signal. The present invention relates to a display processor subsystem that modifies the target FE control signal to enable use of the FE control signal.

[Conventional technology and its problems]

A semiconductor integrated circuit chip has a large number of leads that must be connected to lead-out terminals of a lead frame. The extraction terminals are usually arranged in a pattern adjacent to the outer periphery of the chip.

Typically, a computer-controlled automatic wire bonding machine is used to bond thin wires between each pad of a chip and its lead frame. Such automatic wire splicers have the capability of interconnecting 4 to 8 wires per second and can fully interconnect typical integrated circuit chips at a rate of 915 to 30 chips per minute.

The manufacturing trend in the integrated circuit industry is to mass produce increasingly smaller integrated circuits. Under such conditions, when slight discrepancies or malfunctions occur in the computer-controlled automatic wire splicing machine, if these irregularities are not immediately discovered and repaired, incorrectly connected emergency A large number of chips will be manufactured. Detection of inconsistencies or malfunctions in a computer-controlled automatic wire splicer can only occur after the automatic wire splicer has connected a chip to its lead frame. In short, each interconnect must be tested, including each pad on the chip and each bond in the lead frame.

The time required to bond and inspect lines of fully interconnected chips in a lead frame is significant. In particular, the inspection time should be comparable to the time required to interconnect the wires with a self-exciting wire splicer. Otherwise, the economies realized by using a high-capacity, fully automatic computerized machine are lost.

Furthermore, if the inspection time is long compared to the chip interconnection time, the only way to realize the economic efficiency of the line bonding machine is to periodically inspect the output products of the line bonding machine. This is a device that greatly reduces quality control. For example, if the test time is long enough to test only one of the fully interconnected chips 10001i5, it is possible that there may be up to 1000 loosely connected chips. For the same reason, 51x+7 of interconnected chips
! If the test time can be shortened so that the ``,r test can be performed, the maximum possible number of incorrectly connected chips can be reduced to five.

Therefore, there is a need for high speed automated inspection of the bonds and lines that interconnect an integrated circuit chip to its lead frame. Such automatic inspection equipment must be capable of inspecting lines and pounds with dimensions on the order of tens of microns. Such equipment must also be able to accommodate height differences between each pad on the chip and each pad on the lead frame. Finally, such test equipment should be able to determine the continuity and contour of wire loops interconnecting two pads, as well as between adjacent wire loops and at least at the edges of the chip and islands on the chip. It must be possible to indicate four connections between one side and the line loop.

There are automated optical inspection systems for two-dimensional surfaces such as photomasks, integrated circuit wafers, and semiconductor chips. Typically, in such devices, a magnified flat image is optically generated on a photosensitive surface to generate a pattern. The pattern is compared to known patterns. Such self-effective pattern recognition devices are limited to applications where the depth of the surface being inspected is small compared to its lateral dimensions;
It has not yet been considered possible to do so in cases where the depth of the surface to be inspected along the optical or inspection axis of the device varies significantly.

[Summary of the invention]

The programmable optical inspection device of the present invention provides an optical inspection system capable of generating images at depths that are consistent with the optical inspection axis without changing the magnification of the image formed and independently of the illumination. /Includes a mechanical 1Jl inspection device. This optical/mechanical scanning device is used for moving and precisely positioning a television camera along orthogonal (x-y) horizontal plane axes within the image plane provided by the scanning device's optics. Including stand. A digitizer receives a television video signal from a television camera and converts the received video signal into a digital video signal. These digital video signals are stored, parsed, translated, and processed to retrieve data. The device includes a primary keyboard and trackball that allow the operator to interact with the inspection procedure, as well as a main video
and a display device capable of displaying at least one of stored video, processed video, and data obtained by processing digitized video.

The main advantages of the programmable optical inspection device of the present invention are its automatic performance and its ability to inspect image surfaces with large variations in color along the inspection optical axis.

The optical/mechanical f-device of the present invention includes the following.

a. The surface to be inspected can be illuminated in bright field or dark field.

b. The depth of field of the light image can be independently varied by illuminating the surface to be inspected.

C9 A mechanism that allows the image of an object to be accurately focused on the photoelectric detection surface of a television camera without significantly changing the magnification of the image.

The primary purpose of the optical/mechanical scanning device of the present invention is to project a nearly three-dimensional, low-magnification optical image onto the photoelectric detection surface of a television camera for comparison with a known pixel database.
The purpose is to form an image with a specified pixel size.

[Actual pain example]

Hereinafter, the present invention will be described in detail with reference to the drawings.

First, reference is made to FIGS. 1 and 2. The key mechanical and optical components of the programmable optical inspection device of the present invention include the surface 32 of the sample to be inspected and the dark + Jf field along the optical image axis or Z field of the device. An annular illuminator 1 for illuminating, an F-stop aperture 12 combined with a solenoid controller 11, and an objective lens (50
W) 2, including a beam splitter 3, a rear magnifying lens 4, an upper aperture 30 combined with the rear magnifying lens, and a television camera 26;

Bright-field illumination of the sample surface 32 is provided along the illumination axis I by a light source 10 of small apparent size.

In order to obtain an apparently larger light source, the street expander 8 can be moved in front of the light source 10 by means of an actuator 9 associated with it. A focusing lens 7 in the fang 1 collects light from the light source and sends the collected light through a diaphragm 6 to a second focusing lens 5. The second focusing lens 5 directs the light from the light source 10 along the illumination work to the beam splitter 3 where it is directed along the Z-axis to illuminate the sample surface 32.

A television camera 26 is installed on a stand 27 that can be moved along a horizontal Y-axis and a Z-axis, which is an optical axis, by a stepping motor 25 and a feed screw associated therewith. Base 27 and stepping motor 2
5 is mounted on a movable carriage 22. This movable carriage is adapted to be moved along a horizontal X-axis that is orthogonal to both the horizontal Y-axis and the two optical axes. Carriage 22 is supported on guide rails 21 . The guide rail is fixed to the frame 41 of the device. The carriage 22 is moved along the pX axis by the stepping motor 19.

The center position of the field of view of the television camera 26 is positioned along the X-axis by the magnetic linear scale encoder 20 and along the Y-axis by the magnetic linear scale encoder 23. More specifically, the magnetic linear scale encoder 20.23 has a bar with a magnetically encoded linear scale and a sensor.

The sensor reads the scale as the pupil moves through the sensor. Usually the sensor is mounted on a stationary frame, with one end of the rod fixed to the town, BjJ element, in the practical example described here, the carriage 22 and the platform 2γ. A suitable magnetic linear scale encoder is manufactured by Sony Corporation as υ5R721.

An important component of the scanning device of the present invention is a mechanism for moving the focal point of the post-magnification/zoom 4 up and down along the optical axis, that is, the Z axis. In particular, when the sample surface 32 is placed within the focal plane of the objective lens 2, the parallel light reflected onto the sample surface is
The light is sent from the objective lens 2 to the rear magnifying lens 4 for any point on the object. This can be done by moving the rear magnifying lens up and down along the Z-axis, which is the optical axis of the device)
The light beam between the objective lens 2 and the rear magnifying lens 4 is kept almost unchanged. However, the focus of the light beam from the rear magnifying lens moves up and down along two axes in the vicinity of the photoelectric detection surface of the television camera 26. The depth of the field of view of the rear magnifying lens 4 in the image plane is deeper by a factor M than the depth of field in the vicinity of the sample surface.

Here, M is a value obtained by dividing the focal length of the rear magnifying lens 4 by the focal length of the objective lens 2. Therefore, by moving the rear-stage magnifying lens 4 up and down along two axes, various depths of the field of view of the sample surface 32 can be adjusted by photoelectric detection of the television camera 26, without changing the magnification of the formed image. A very sensitive mechanism is obtained by focusing the focal point on the surface. Such a mechanism allows focusing along two axes of the device without making adjustments along the illumination axis (1) of the device.

Accordingly, referring to Figure f1, stepping motor 13 rotates cam 14 to raise and lower swing arm 15 which is pivotally mounted at position 24 on frame 41 of the device. The distal end of the swinging arm 15 includes a yoke 33 for receiving the cylindrical lens sleeve 31 of the rear magnifying lens 4 on the underside of the diametrically opposite post 34 . As shown,
The swing arm 15 and yoke are adapted to support or raise the lens sleeve 31. The swinging arm 28 of the fang 1 is also pivotally mounted to the frame 41 of the device and includes a yoke 35 which receives the cylindrical lens sleeve 31 of the rear magnifying lens 4 on the post 34. A spring 29 presses or pre-forces the swing arm 28 against the support yoke 33 of the swing 15.

A limit sensor constitutes a 1-zero position indicator that moves up and down along the two axes of the rear magnifying lens.

This limit sensor includes a rotating element 16 coupled to the shaft of a stepper motor 13 and a rotating element 17 mounted to the frame of the device.

The size of the depth of field of the objective lens and the post-magnifier/image semipronation can also be adjusted by changing the apparent size of the light source 10. In particular, the light source 10 has a small apparent size. By rotating the diffuser 8, which is held within the frame 18, into the illumination beam path, a light source with relatively large apparent dimensions is constructed. In particular, a focusing lens 7 collects the light coming directly from the light source 10, but still coming from the diffuser 8, and sends the collected light through the field aperture and the focusing lens 5 along the illumination axis (1). From there the light is reflected by a beam splitter 3 and sent through an objective lens 2. Those optical elements are light source 10 (
The light from the diffuser 8 (of small apparent size) or the diffuser 8 (of large apparent size) reaches the f-stop 1 of the objective lens 2.
It is placed so that the images are connected near 2. A field aperture 6 along the illumination feature is imaged onto the plane of the sample surface 32 by the focusing lens 5 and the objective lens 2. If a light source 10 with small apparent dimensions is used, the sample will be exposed to a relatively narrow cone-shaped light beam. illuminated by. 96 gives a sufficiently deep field of view along the Z axis. When a diffuser 8 is inserted to obtain a light source with a large apparent size, the sample surface is illuminated with a large cone of light, and as a result To 2@? 9) Depth of field of vision decreases.

Therefore, if the sample surface 32 has a relatively large dimension along the OZ axis, a light source 10 with a small apparent dimension can be used for sample surface illumination.

If the sample surface is not large enough along the Z axis, or if a sufficient depth of field cannot be obtained,
The diffuser 8 can be rotated into the illumination path to significantly reduce the depth of field.

In summary, the objective lens 2 and the post-magnifying lens 4 define an image plane along two axes that are the optical axis of the device. A television camera is moved along the X and Y axes with its photoelectric detection surface aligned with the image plane. A magnetic linear scale encoder provides a precise positioning mechanism for centering the field of view of the television camera 26. Therefore, the stepping motors 19 and 25 move the television camera 26 along the X and Y axes.
By moving along the axis, the device of the invention
The sample surface can be scanned within the Y plane.

Depending on the application, if the dimensions of the sample surface 32 along the two axes (vertical axes) of the device are to be investigated by scanning, the actuator 9 brings the diffuser into alignment with the illumination optical axis (■) or adjusts the alignment state. The diffuser is moved to remove the diffuser from the light source 10 to switch the device between a light source 10 with a small apparent size giving a deep depth of field and a light source 10 with a large apparent size giving a shallow depth of field. The illuminance at sample 32 cannot be changed significantly. Then, by moving the rear-stage magnifying lens 4 up and down along the Z-axis by the stepping motor 13, various heights of the sample surface can be adjusted using the television camera 26.
can be focused on the photoelectric detection surface.

For example, if the pads of a chip and the leadframe are in the same plane, the images of those pads and the leadframe can be tied together, or if the pads are at different heights, the images of those pads can be tied together. Sequential tying is possible with the device of the invention. Similarly,
Determining the height of the line loop is made possible by first connecting the images of the pads and then connecting the images of the line loops. (Shallow field of view depth.) It will be understood by those skilled in the field of optics that the focusing lens 7 is not absolutely necessary. If the focusing lens 7 is eliminated, the focusing lens 7 is arranged such that the apparent dimensions of the diffused light source constituted by the diffuser 18 when focused by the objective lens 2 are approximately the same as the dimensions of the F-stop aperture 12 of the objective lens 2. 5 and viewing aperture 6 must be adjusted.

Another configuration of the scanning device of the programmable inspection device of the present invention is shown in a partially cutaway side view (FIG. 2) and a carriage for allowing the television camera 26 to be cut into four sections in the X-Y plane. Plan view showing details of 22 and stand 27 (Fig. 3)
It is shown in In particular, with reference to FIG. 2, the optical components of the device are mounted on a sturdy device frame 41.

A vertical space is provided on the underside of the annular illuminator 1 for receiving a fermentation lead frame feeding mechanism (not shown).

The lead frame transport mechanism moves the lead frame on which the interconnected chips are placed under the illuminator 1 perpendicular to the Z axis of the device. The stand 2T on which the television camera 26 is attached is connected to the circular guide rail 43.
It is supported on roller bearings that rotate on top. In order to provide a three-point or triangular support on each guide rail 21.degree. 43, the platform 27 and the carriage 22 must have at least three pairs of roller bearings 42. A feed screw 46 rotated by a respective stepper motor 19.25 moves the carriage 22 in the center of the triangular head formed by the contact points of a particular roller bearing and a particular guide rail on both sides of the carriage 22/pedestal 27. and is connected to the stand 27.

In this way, as the platform 27 or carriage 22 moves on their respective guide rails, the reforming force and the driving force are directly offset to eliminate rolling moments.

Referring now to FIG. 3, the center of the moving mass of the platform 2γ and the carriage 22 must be placed at the center of the triangle formed by the three-point support provided by the roller bearings 42. The connection between the lead screw 46 and the carriage 220 for moving the television camera 26 along the X-axis is made at a point that coincides with the mean center of *ilt of the structure. In particular, the table 27 moves back and forth on the carriage 22 along the Y axis →Φ.

Platform 27-! In order to minimize movement errors due to lateral displacement of the bamboo carriage 22 on the respective guide rail, at least one of the guide rails and bearings on one side of the platform 27 and the carriage 22 is preloaded by a spring 44. must be added.

Finally, carriage 22 and platform 27 include an anti-play coupling assembly 47 to eliminate play when the lead screw reverses the direction of movement of carriage 22 or platform 27.

In particular, with reference to FIG. 4, the anti-play coupling assembly 47 includes a first threaded element 48 mechanically coupled to the carriage or platform and a radially loaded force with respect to the first threaded element 48. and a second threaded element 49. The threaded element 49 of the fang 2 includes a bar 51 . This burl 51 extends radially outwards and is adapted to engage a leaf spring element protruding from a face 54 of the threaded element 48 of the other. Usually, the distal end of the leaf spring element is locked in a longitudinal slot 53 provided on the circumference of the threaded element 48 of the fang 1.

Next, the operation will be explained. The feed screw is indicated by arrow 56 °C
When rotated clockwise, leaf spring element 52 applies a force between the first threaded element and the second threaded element to maintain engagement therebetween. When the feed screw is rotated counterclockwise, the four forces of the engaging helical lands (not shown) of each screw element maintain engagement of the contact surfaces of the respective screw threads.

A particular advantage of said anti-play coupling assembly is that the force exerted by the leaf spring element need only be sufficient to maintain a contact relationship between the respective faces of the threaded element. In particular, the elasticity applied by the plate HC deforms each screw element relative to each other and at least one of the feed screws 46, and inclines it in the fine direction. is not used. Therefore, the spring force of the plate spring can be relatively small.

In the device of the present invention, it is not necessary for the feed screw 46 to accurately place the center of view of the television camera 27 at a specific position;
It should be understood that it is only necessary to move the center to an approximate position. A magnetic linear scale encoder 20.23 provides data for determining the coordinates of the center of view of the television camera. In other words, Steppi/Gmota 19.25
The carriage 22 and the platform 2γ move each other.
is combined with a magnetic A-line scale encoder 20, 23 to traverse an X-Y horizontal plane that coincides with the image plane of the objective lens 2 and the subsequent magnifying lens 4 fixed to the Freno lens 41. To enable a television camera to perform self-excited scanning. Furthermore,
1 so that the lead frame feeding device aligns each wafer on the lead frame with the optical axis (2 axes) of the eclipse device.
Make it 8F'dJ. In short, with the exception of the rear magnifying lens 4, the optical components and optical path of the scanning device of the programmable optical inspection device of the invention remain stationary.

The materials and dimensions of Kimmeridge 22 and platform 2γ are selected to minimize mass and inertia limitations on the speed at which the television camera moves as it is moved in the X-Y plane to scan the image plane. Should.

The advantage of the apparatus described above is that the image projected by the optical system of the apparatus can be magnified onto the focal image plane, and the sample surface can be inspected for irregularities, abnormalities, and defects. be able to give sufficient details. The field of view of the television camera need not receive the entire image projected by the optical system of the scanning device, but rather the field of view of the sample surface 3.
It is only necessary to have a field of view sufficient to accommodate the dimensions of a particular part of 2 when it is magnified in the image plane.

Refer now to FIG. An optical/mechanical assembly 60, shown in detail in FIGS. 1-4, interfaces with the device's processor 64 via a hardware interface device 162.
interconnected. A digitizer 66 receives the output of the video camera via a camera controller 68 and performs high-speed video processing (H8IP) via a 32-bit video processing (IP) path T0.
Connected to a subsystem. The high speed video processing subsystem includes a storage device controller 72, a storage device 74, an arithmetic processor 76, and a control processor T8. Digitizer 66 provides output to display processor 80.

Storage device controller 72, storage device T4, arithmetic processor 76, control processor 78, and disk controller 82
, display processor 80 , device processor 64 , and main processor 84 communicate with each other via a 16-bit device bus 86 . Disk controller 82 has access to a hard (Rye/Chester) disk 88 and one or more floppy disks 90. A trackball and keyboard 92 communicate with the device processor 64 to move the television camera within the image plane and to move the rear magnifying lens 4 (FIG. 1) up and down along two axes. The sample surface (320) of the image along the vertical dimension
- a two-way round cut].

Main processor 84 also communicates with a main controller or computer (not shown). A master controller or computer controls the movement of the lead frame feeder to advance the interconnected chips in alignment with the two axes of the optical/mechanical scanning assembly.

Main processor 84 performs real-time multitasking operations. This real-time multitasking operation allows several tasks to be handled simultaneously. In addition to playing an important role in analytical testing, main processor 84 handles communication throughout the system, controls the type and number of tests to be performed, and receives the results of those tests. The main processor 84 also controls all mass storage devices for the device, as well as input and output to and from external devices. ! 11
control

In contrast, device processor 64 also provides tf+ control of the optical/mechanical scanning assembly in conjunction with the main processor. Device processor 64 receives instructions from the main processor to appropriately operate the optical/mechanical scanning assembly.

In accordance with the present invention, it is possible to automatically determine whether the wire loops connecting the lead frame to the ronds of the chip are too high or sag.

It is also possible to determine whether the line touches or is about to touch the edge of the chip, an island or another pad on the chip.

The programmable optical inspection apparatus of the present invention has been described in terms of preferred embodiments. However, even changing the various components of the scanning device, including how the optical/mechanical components of the scanning device are controlled by algorithms, programs, and instructions, can improve the device of the present invention. It will be understood that changes, omissions and corrections may be made without departing from the spirit of the invention.

[Brief explanation of drawings]

Figure 1 is an exploded, perspective view showing important parts of the optical/mechanical scanning device of the present invention, and Figure 2 is a partially cut away top view showing the optical and mechanical components of the scanning device of the present invention. Figure 3 is a plan view showing the parts of the X-Y platform for moving the television camera across the image plane given by the scanning device of the present invention, and Figure 4 shows the respective feed screws and the components of the platform. FIG. 5 is a block diagram illustrating the relationship of the functional components of the programmable optical detour system of the present invention. 2...Objective lens, 3...Beam splitter, 4
...Later enlargement/Z, 5,7...Focus/Z,
8... Diffuser, 9... Actuator, 1
0...Light source, 12...F stop aperture, 13i9, 25...Stepping motor, 15...
...R6 recommended arm, 18...diffuser, 20.23
... Linear scale encoder, 22 ... Carriage, 2
6...TV camera, 2T...unit, 43...
・Guide rail, 47...play prevention coupling assembly, 48
．． 49... Screw element, 52... Leaf spring element, 6
0...Optical/'mechanical assembly, 64°...Device processor, 66...Digitizer, 68...TV camera II @l device, 72...Storage device control γ4...Storage device, 76...Arithmetic processor, 78...Control processor, 80...Display processor, 84...Main processor. Patent applicant: KLA Instruments Corporation

Claims (20)

[Claims] (1) Having a photosensitive surface included in the X-Y plane, and having a photosensitive surface included in the X-Y plane,
electro-optical means operative to generate electrical signals corresponding to each pixel of an image projected onto the photosensitive surface along a Z-axis perpendicular to the Y-plane; a rear magnifying lens means arranged to enable selection of images of various planes of the object taken along the second portion of the Z-axis and including surface portions of the three-dimensional object to be examined; and irradiating the three-dimensional object with illumination light along a third portion of the Z-axis that includes the second portion of the Z-axis instead of the first portion of the Z-axis. and an electronic device for comparing said electrical signal with a predetermined reference signal to determine whether the surface being inspected has characteristics that fall within predetermined tolerance limits. An optical inspection device that inspects the surface of three-dimensional objects. (2) The optical inspection device according to claim 1, wherein the illumination means emits light that appears to be coming from a relatively small light source, and when the illumination means emits light that appears to come from a relatively large light source. An optical inspection device characterized by being able to switch between a state in which it emits visible light and a state in which it emits visible light. (3) The optical inspection apparatus according to claim 2, wherein the illumination means is arranged along an illumination axis that is partially coaxial with the third portion of the Z-axis. a relatively small light source; and a light diffusing means movable between a position not intersected by the illumination axis and a position intersected by the illumination axis, such that light from the relatively small light source crosses the illumination axis. An optical inspection device characterized in that it appears to emanate from a relatively large light source along and through said diffusing means. (4) The optical inspection device according to claim 3, wherein the illumination means is arranged concentrically with the Z axis,
An optical inspection device further comprising a tubular light source for illuminating a dark portion of the three-dimensional object. (5) The optical inspection apparatus according to claim 4, wherein the electro-optical means is configured to move the photosensitive surface in the X-Y plane in a direction transverse to the Z-axis. An optical inspection device further comprising selectively moving carriage means. (6) The optical inspection apparatus according to claim 5, wherein the carriage means includes a first drive means for moving the electro-optical means in the X direction and a first drive means for moving the electro-optical means in the Y direction. 2. An optical inspection device comprising: 2 driving means. (7) The optical inspection apparatus according to claim 6, wherein the carriage means includes a first magnetic encoder means for detecting the position of the electro-optical means in the X direction, and a first magnetic encoder means for detecting the position of the electro-optical means in the X direction. second magnetic encoder means for detecting position in the Y direction. (8) The optical inspection device according to claim 6, wherein the first driving means and the second driving means include a stepping motor and a feed screw driven by the stepping motor. , each including an anti-play assembly coupling said carriage means to said lead screw, said anti-play assembly including a first member attached to said carriage means and threaded onto said lead screw; a second member screwed into the screw and disposed in contacting relationship with the first member; and a second member connected between the first member and the second member to maintain the contact relationship. An optical inspection device characterized in that it includes elastic means for applying an acting elastic force between the first member and the second member. (9) The optical inspection apparatus according to claim 7, wherein the image generating means is an actuator driven by a stepping motor that selectively moves the rear magnifying lens means along the Z-axis. An optical inspection device further comprising: (10) The optical inspection apparatus according to claim 1, wherein the electro-optical means is configured to move the photosensitive surface in the X-Y plane in a direction transverse to the Z-axis. An optical inspection device further comprising selectively moving carriage means. (11) An optical inspection apparatus according to claim 10, wherein the carriage means moves the electro-optical means
a first driving means for moving the electro-optical means in the Y direction;
and second driving means for moving in the direction. (12) The optical inspection apparatus according to claim 10, wherein the carriage means
first magnetic encoder means for detecting position in the direction;
a second detecting the position of the electro-optical means in the Y direction;
1. An optical inspection device further comprising: magnetic encoder means. (13) The optical inspection device according to claim 11, wherein the first driving means and the second driving means include a stepping motor and a feed screw driven by the stepping motor. and an anti-play assembly coupling said carriage means to said lead screw;
The anti-play assembly is arranged with a first member attached to the carriage means and threaded onto the lead screw, and a first member threaded onto the lead screw and arranged in contacting relationship with the first member. a second member; a resilient means coupled between the first member and the second member for applying a resilient force between the first member and the second member that acts to maintain the contact relationship; An optical inspection device comprising: (14) The optical inspection apparatus according to claim 13, wherein the carriage means includes a first magnetic encoder means for detecting the position of the electro-optical means in the X direction, and a first magnetic encoder means for detecting the position of the electro-optical means in the X direction. second magnetic encoder means for detecting the position in the Y direction of the optical inspection apparatus. (15) The optical inspection apparatus according to claim 14, wherein the image generating means is an actuator driven by a stepping motor that selectively moves the rear magnifying lens means along the Z-axis. An optical inspection device further comprising: (16) The optical inspection apparatus according to claim 1, wherein the illumination means further includes an annular light source arranged concentrically with the Z axis and illuminating a dark part of the three-dimensional object. An optical inspection device comprising: (17) The optical inspection apparatus according to claim 16, wherein a portion of the illumination means
a relatively small light source disposed along an illumination axis coaxial with a portion of the illumination axis; and a light diffusing means movable between a position not intersected by the illumination axis and a position intersected by the illumination axis. , whereby light from the relatively small light source appears to exit from the relatively large light source along the illumination axis and through the diffusing means. (18) The optical inspection apparatus according to claim 12, wherein the illumination means emits light that appears to be coming from a relatively small light source, and when the illumination means emits light that looks like it comes from a relatively large light source. An optical inspection device characterized by being able to switch between a state in which it emits visible light and a state in which it emits visible light. (19) The optical inspection apparatus according to claim 18, wherein a portion of the illumination means
a relatively small light source disposed along an illumination axis coaxial with a portion of the illumination axis; and a light diffusing means movable between a position not intersected by the illumination axis and a position intersected by the illumination axis. , whereby light from the relatively small light source appears to exit from the relatively large light source along the illumination axis and through the diffusing means. (20) The optical inspection apparatus according to claim 17, wherein the image generating means is an actuator driven by a stepping motor that selectively moves the rear magnifying lens means along the Z-axis. An optical inspection device further comprising: