CN1977144A - Sensor device and stage device - Google Patents

Abstract

The invention provides a detection device and a stage device capable of detecting the state of the five degrees of freedom of the stage by using a standard lattice having an easily manufacturable shape, and improving detection accuracy, concerning the detection device and the stage device for detecting the state of the stage moved highly accurately. The state to the standard lattice is detected based on a change of a plurality of reflected lights by a detection means equipped with a light source part for irradiating light toward the standard lattice, a spectroscopic means for spectrally diffracting the light into a plurality of reflected lights by a plurality of apertures, and a detector for receiving the plurality of reflected lights in whole.

Description

Pick-up unit and table apparatus

Technical field

The present invention relates to pick-up unit and table apparatus, particularly the status detection device and the table apparatus of the platform that moves accurately of detection.

Background technology

Corresponding to highly integrated, low price, the requirement of the high productivity of the semiconductor exposure device of making semiconductor equipment, high precision int, high speed etc. is uprised as the semiconductor equipment of the foundation of IT technology.For platform, need have the high speed multiple degrees of freedom table apparatus of the moving range of precision about 10nm and hundreds of mm as the key component of semiconductor exposure device.Therefore, need critically the multiple degrees of freedom position and the posture of Metering measuring table, feed back its result and carry out the positioning control of platform.

Position instrumentation mode as in the past locating device generally adopts optical profile type linear encoder, laser length measuring machine and autocollimator etc.These are measured as ultimate principle with the length or the posture of 1 dimension basically, carry out the instrumentation of position or posture by its combination of a plurality of.

In addition, at the laser interferometer that is used for the high precision instrumentation, owing to utilize laser to carry out the instrumentation of the position of platform (orienting object), so the problem that waits the precision reduction that makes the instrumentation value of waving of air in the device that is placed because of platform is arranged.In addition, in laser interferometer,, need on each direction, dispose metal tube as the light path of laser for the swing that prevents air owing to optics can only be placed the outside of platform.Therefore, the problem that has that whole maximize table apparatus, its structure becomes complexity etc.

And then, make platform under the situation of Z axle rotation, have from the reflected light of platform and depart from and can not carry out the problem of the position probing of XY direction from interferometric light accepting part.As the pick-up unit that solves such problem, the known pick-up unit (for example with reference to patent documentation 1 and patent documentation 2) that pair benchmark grid irradiating laser is arranged, detect 2 dimension angles of the catoptrical XY direction that reflects by benchmark grid (angle grid) by 2 dimension angular transducers.

Fig. 1 is the skeleton diagram that expression has the pick-up unit in the past of benchmark grid and 2 dimension angular transducers.As shown in Figure 1, in pick-up unit 300 in the past, change the position probing of carrying out the XY direction by 12 output of tieing up angular transducer 290.

This 2 dimension angular transducer 290 is sensors of inclination of the face of detection reference grid, the variation of the normal direction of face that can the detection reference grid.Thereby, can detect the inclination or the normal variation of XY direction (both direction) by 2 dimension angular transducers 290.Benchmark grid 320 is that both direction (directions X and Y direction) the upper set ground of quadrature in the plane is formed with the benchmark grid with the peak and valley of known function, uses sinusoidal wave in the shape of benchmark grid 320.

Then, with reference to Fig. 22 dimension angular transducers 290 shown in Figure 1 are described.Fig. 2 is the figure of expression 2 dimension angular transducers.2 dimension angular transducers 290 are based on the geometrical optics sensor of autocollimation method.

As shown in Figure 2,1 laser 310 that shines from LASER Light Source 310 passes through polarisation beam separator 302 and 1/4 wavelength plate 303, incides on the surface of benchmark grid 320.By 302 reflections of polarisation beam separator, laser 312 incides in the autocollimator 305 by the laser 312 of the surface reflection of benchmark grid 320.Autocollimator 305 has the structure that comprises object lens 306 and detect the photo detector 307 of facula position.

Patent documentation 1: Japanese kokai publication hei 8-199115 communique

Patent documentation 2: No. 2960013 communiques of Jap.P.

But, in above-mentioned autocollimation method, the target (being generally cross curve) that need make the focus that is in object lens 306 is in the unlimited distance imaging, directional light by the flat mirror reflects of the front that is in object lens 306 is imaged on the position that conjugates to the target face, reads the small angle displacement of level crossing according to the displacement in the face of the cross curve of imaging.Therefore, need expensive and complicated parts such as autocollimator 305 grades, the problem that exists the cost of pick-up unit 300 to uprise.

In addition, in order to carry out high-resolution position probing, benchmark grid 320 shortened with the cycle of many hot spots, might geometric optical theory was false because of interference of light and diffraction thereupon.Therefore, the problem that is difficult to detect is accurately arranged.In addition, for the state to 5 degree of freedom of 2 dimension displacements (displacement of directions X and Y direction) and 3 posture change (with respect to the sense of rotation of X-axis, with respect to the sense of rotation of Y-axis and with respect to the sense of rotation of Z axle) detects, need 32 to tie up angular transducers 300.Thereby, the problem that is difficult to carry out the adjusting between these sensors is arranged.

And then, in table apparatus, while when platform is moved, carry out a pair of linear motor that the position probing drive controlling is located at the both sides of platform.In order to improve the position detection accuracy of this moment, above-mentioned detection device 300 need be made amount of movement and degree of tilt that compact structure more correctly detects linear motor.

In addition, as the pick-up unit beyond above-mentioned, known have by the optical sensor that moves with respect to the aperture plate that on the moving direction of platform, extends to form detect the straight-line detection position that the slit number comes the position of monitor station optically.Can use the displacement of the platform of this straight-line detection position probing moving direction.But, can not use the displacement (for example angle of inclination around each of above-below direction and platform) of the platform of these other directions of straight-line detection position probing.

Therefore, in table apparatus in the past, dispose a pair of straight line detection position in the both sides of platform, according to calculating the deflection angle of obtaining platform by the difference of the detected detection signal in a pair of straight line detection position.And, the angle of inclination of other directions of monitor station not, and the moving of control desk.

Table apparatus in the past is owing to position (amount of movement) the drive controlling linear motor according to the moving direction that is obtained by the straight-line detection position, so can not correctly grasp heeling conditions when platform is moved, other directions.Therefore, have and under the situation that platform tilts, be difficult to correctly to detect to tilt what problem of which direction.

Summary of the invention

The present invention makes in view of the above problems, and purpose provides a kind of pick-up unit and table apparatus that uses the detection at the benchmark grid of the shape of easy manufacturing, the displacement that can easily carry out platform and angle of inclination and can improve the precision of detection.

In order to solve above-mentioned problem, pick-up unit of the present invention is characterised in that to possess: the benchmark grid has the shape that changes periodically on 2 dimension directions; Light source is to said reference grid irradiates light; Spectrophotometric device has a plurality of peristomes, will be multi-beam from the light beam split of above-mentioned light source irradiation by above-mentioned a plurality of peristomes; Testing agency has the photo detector that the multi beam reflected light by the reflection of said reference grid is subjected to simultaneously light; And above-mentioned testing agency is subjected to the catoptrical variation of above-mentioned multi beam of light according to above-mentioned photo detector, detects the state of relative said reference grid.

According to above-mentioned detection device, will be radiated at by the multi-beam after the spectrophotometric device beam split on the benchmark grid, will be subjected to light by photo detector simultaneously from the multi beam reflected light of benchmark grid reflection, testing agency according to multi beam catoptrical variation carry out status detection.Therefore, even when illuminated some defectiveness in the benchmark grid of multi-beam, also can carry out status detection according to the catoptrical variation of the multi-beam on the normal benchmark grid that is irradiated onto other.The situation of carrying out status detection with in the past irradiation 1 bundle light, according to its reflected light is compared, and can carry out status detection more accurately.

Above-mentioned detection device also can constitute, and above-mentioned photo detector is made of a plurality of photodiodes; In the central authorities of the face of the above-mentioned testing agency that above-mentioned multi beam reflected light is subjected to light, have at least and carry out with the X-axis being the status detection that moves of the rotation of turning axle and being 4 photodiodes of the status detection that moves of the rotation of turning axle with the Y-axis.According to this pick-up unit, by central authorities 4 photodiodes are set, can carry out being the status detection that moves of the rotation of turning axle and being the status detection that the rotation of turning axle is moved with the Y-axis with the X-axis at the face of the testing agency that the multi beam reflected light is subjected to light.

Perhaps, above-mentioned detection device also can constitute, and has at least at the face of above-mentioned testing agency four jiaos that to be used for carrying out with the Z axle be that two of the status detection that moves of the rotation of turning axle are one group photodiode.According to this pick-up unit, be one group photodiode by be provided with two at testing agency four jiaos, can carry out with the Z axle is the status detection that the rotation of turning axle is moved.

Perhaps, above-mentioned detection device also can constitute, and uses charge-coupled device (CCD) in above-mentioned photo detector.According to this pick-up unit, by using charge-coupled device (CCD), can be subjected to light simultaneously to multi beam reflected light by the reflection of benchmark grid as photo detector, by the catoptrical variation of multi beam that detects by testing agency, detect the state of relative datum grid.

Perhaps, above-mentioned detection device also can constitute, and the central shaft that the said reference grid constitutes with respect to the said reference grid is symmetrical shape.According to this pick-up unit, be symmetrical shape by the central shaft that the benchmark grid is constituted with respect to the benchmark grid, compare with the benchmark grid that on 2 dimension directions, has sinusoidal wave shape in the past, can more easily make the benchmark grid.

In order to solve above-mentioned problem, pick-up unit of the present invention is characterised in that to possess: the benchmark grid has from the teeth outwards in 2 dimensions and alternately forms the concave curved surface with predetermined shape and the detection faces of convex surface on the directions; Illuminating part is provided with movably with respect to the said reference grid, shines the multi beam directional light from the vertical direction of said reference grid towards above-mentioned detection faces; Light accepting part is set to move integratedly with above-mentioned illuminating part, has a plurality of photo detectors that the above-mentioned multi beam directional light of transmission said reference grid are subjected to light.

According to this pick-up unit, owing to be with the structure of benchmark grid configuration between illuminating part and light accepting part, so can realize the simplicity and the densification of pick-up unit, and can be according to the variation that is subjected to light intensity distributions of multi beam directional light and correctly detect illuminating part and light accepting part with respect to the relative position of benchmark grid, can correctly detect corresponding to the displacement of two directions of the detection faces of benchmark grid with corresponding to the angle of inclination of all directions of benchmark grid.

Above-mentioned detection device also can constitute, and above-mentioned illuminating part has light source and will be the spectrophotometric device of multi beam directional light from the light beam split of above-mentioned light source.

Perhaps, above-mentioned detection device also can constitute, and above-mentioned spectrophotometric device has in 2 dimensions and alternately forms the concave curved surface with predetermined shape and the plane of incidence of convex surface on the directions.

Perhaps, above-mentioned detection device also can constitute, and above-mentioned light accepting part has the photo detector of the number of Duoing than above-mentioned multi beam directional light, sets 1 photo detector at least corresponding to 1 bundle directional light.

Perhaps, above-mentioned detection device also can constitute, possesses arithmetical organ, this arithmetical organ is transfused to the detection signal corresponding to the light intensity of the above-mentioned multi beam directional light that is subjected to light by above-mentioned photo detector, according to the rate of travel of the above-mentioned illuminating part of the change calculations of each light intensity distributions with respect to the said reference grid.

Perhaps, above-mentioned detection device also can constitute, and above-mentioned arithmetical organ calculates above-mentioned illuminating part and the light accepting part relative tilt angle with respect to above-mentioned detection faces according to the variation of the light intensity distributions of the above-mentioned multi beam directional light that is subjected to light by above-mentioned a plurality of photo detectors.

Perhaps, above-mentioned detection device also can constitute, the said reference grid possesses transparency carrier, is provided in lip-deep the 1st benchmark grid of above-mentioned transparency carrier and makes it and above-mentioned the 1st benchmark grid constitute 180 degree towards mode be provided in the 2nd benchmark grid at the back side of above-mentioned transparency carrier.

In addition, in order to solve above-mentioned problem, pick-up unit of the present invention is characterised in that to possess: the benchmark grid has from the teeth outwards in 2 dimensions and alternately forms the concave curved surface with predetermined shape and the detection faces of convex surface on the directions; Reflecting surface is formed on the back side of said reference grid; Illuminating part is provided with movably with respect to the said reference grid, shines the multi beam directional light from the vertical direction of said reference grid towards above-mentioned detection faces; Light accepting part is set to move integratedly with above-mentioned illuminating part, has a plurality of photo detectors that the multi beam directional light from above-mentioned reflecting surface reflection are subjected to light.And then in order to solve above-mentioned problem, pick-up unit of the present invention is characterised in that to possess: the benchmark grid has from the teeth outwards in 2 dimensions and alternately forms the concave curved surface with predetermined shape and the detection faces of convex surface on the directions; Reflecting surface is formed on the above-mentioned detection faces; Illuminating part is provided with movably with respect to the said reference grid, shines the multi beam directional light from the vertical direction of said reference grid towards above-mentioned detection faces; Light accepting part is set to move integratedly with above-mentioned illuminating part, has a plurality of photo detectors that the multi beam directional light from above-mentioned reflecting surface reflection are subjected to light.According to these pick-up units, owing to be to make illuminating part and light accepting part be opposite to the reflecting surface of benchmark grid, the multi beam directional light from reflecting surface reflection is subjected to the structure of light, so can realize the simplicity and the densification of pick-up unit, and can be according to the variation that is subjected to light intensity distributions of multi beam directional light and correctly detect illuminating part and light accepting part with respect to the relative position of benchmark grid, can correctly detect corresponding to the displacement of two directions of the detection faces of benchmark grid with corresponding to the angle of inclination of all directions of benchmark grid.

In addition, in order to solve above-mentioned problem, the platform that table apparatus of the present invention possesses pedestal, move on said base, drive above-mentioned motor, make above-mentioned float-up device that floats with respect to pedestal and detect above-mentioned status detection device, it is characterized in that, above-mentioned detection device possesses: the benchmark grid has the shape that changes periodically on 2 dimension directions; Light source is towards said reference grid irradiates light; Spectrophotometric device has a plurality of peristomes, will be multi-beam from the light beam split of above-mentioned light source irradiation by above-mentioned a plurality of peristomes; Testing agency has the photo detector that the multi beam reflected light by the reflection of said reference grid is subjected to simultaneously light; And above-mentioned detecting element is subjected to the catoptrical variation of above-mentioned multi beam of light according to above-mentioned photo detector, detects the state corresponding to the said reference grid.According to this table apparatus, by using above-mentioned detection device, monitor station is with respect to the displacement and the angle of inclination of pedestal accurately.

Above-mentioned table apparatus also can constitute, and uses planar motors in said motor, uses air bearing in above-mentioned float-up device.According to this table apparatus, in motor, use in planar motors, the float-up device in the table apparatus that uses air bearing, by using above-mentioned detection device, also accurately monitor station with respect to the state of pedestal.

In addition, in order to solve above-mentioned problem, table apparatus of the present invention possesses pedestal, the platform that can set movably with respect to said base, to above-mentioned the driving mechanism of giving driving force, detect above-mentioned the pick-up unit that moves and control above-mentioned driving mechanism so that above-mentioned control gear that moves at a predetermined velocity according to the testing result of above-mentioned detection device, it is characterized in that, above-mentioned detection device possesses: the benchmark grid has from the teeth outwards in 2 dimensions and alternately forms the concave curved surface with predetermined shape and the detection faces of convex surface on the directions; Illuminating part is provided with movably with respect to the said reference grid, sends the multi beam directional light from the vertical direction of said reference grid towards above-mentioned detection faces; Light accepting part is set to move integratedly with above-mentioned illuminating part, has a plurality of photo detectors that the above-mentioned multi beam directional light of transmission said reference grid are subjected to light.According to this table apparatus, by illuminating part that sends the multi beam directional light and the light accepting part that the multi beam directional light of transmission benchmark grid or reflection is subjected to light, can correctly carry out position probing corresponding to two directions of the platform of the detection faces of benchmark grid, and can detect the angle of inclination of the platform of all directions simultaneously, can carry out drive controlling so that revise the inclination of platform accurately platform.

Above-mentioned table apparatus also can constitute, and above-mentioned driving mechanism is a pair of linear motor, and above-mentioned control gear is gone forward side by side and driven above-mentioned a pair of linear motor.Perhaps, above-mentioned table apparatus also can constitute, with above-mentioned detection device be provided in above-mentioned linear motor near.

The invention effect

According to the present invention, the benchmark grid that uses the shape of making easily can be provided, can easily carry out and can improve the pick-up unit and the table apparatus of the precision of detection with respect to the detection at the displacement of the platform of pedestal and angle of inclination.

Description of drawings

Fig. 1 is the skeleton diagram that expression has the pick-up unit of benchmark grid and 2 dimension angular transducers.

Fig. 2 is the figure of expression 2 dimension angular transducers.

Fig. 3 is the cut-open view of table apparatus that expression possesses the pick-up unit of one embodiment of the present invention.

Fig. 4 is the vertical view corresponding to the structure division of area B shown in Figure 3.

Fig. 5 A is the vertical view of relation of schematically representing the propelling power of the driving direction of movable table and directions X and Y direction driver.

Fig. 5 B is the vertical view of relation of schematically representing the propelling power of the driving direction of movable table and directions X and Y direction driver.

Fig. 5 C is the vertical view of relation of schematically representing the propelling power of the driving direction of movable table and directions X and Y direction driver.

Fig. 5 D is the vertical view of relation of schematically representing the propelling power of the driving direction of movable table and directions X and Y direction driver.

Fig. 6 is the vertical view corresponding to the structure division of zone C shown in Figure 3.

Fig. 7 is the figure of expression scale portion and testing agency.

Fig. 8 is the schematic configuration of expression testing agency and the figure of scale portion.

Fig. 9 is the vertical view of beam-splitter.

Figure 10 is the figure that observes testing agency shown in Figure 8 from the direction shown in the arrow G.

Figure 11 is the figure that is illustrated in the model of the testing agency that uses in the simulation.

Figure 12 is the figure that is used for illustrating the phase function of benchmark grid.

Figure 13 is that spot intensity distribution I (x, the result's of variation y) figure have been simulated in expression.

Figure 14 A observes the figure that moving body (movable table 237) distributes with respect to the spot intensity of benchmark grid when displacement takes place directions X from the X1 direction.

Figure 14 B observes the figure that moving body distributes with respect to the spot intensity of benchmark grid when displacement takes place directions X from the X1 direction.

Figure 14 C observes the figure that moving body distributes with respect to the spot intensity of benchmark grid when displacement takes place directions X from the X1 direction.

Figure 14 D observes the figure that moving body distributes with respect to the spot intensity of benchmark grid when displacement takes place directions X from the X1 direction.

Figure 14 E observes the figure that moving body distributes with respect to the spot intensity of benchmark grid when displacement takes place directions X from the X1 direction.

Figure 15 A observes the figure that moving body distributes with respect to the spot intensity of benchmark grid when displacement takes place directions X from the Y1 direction.

Figure 15 B observes the figure that moving body distributes with respect to the spot intensity of benchmark grid when displacement takes place directions X from the Y1 direction.

Figure 15 C observes the figure that moving body distributes with respect to the spot intensity of benchmark grid when displacement takes place directions X from the Y1 direction.

Figure 15 D observes the figure that moving body distributes with respect to the spot intensity of benchmark grid when displacement takes place directions X from the Y1 direction.

Figure 15 E observes the figure that moving body distributes with respect to the spot intensity of benchmark grid when displacement takes place directions X from the Y1 direction.

Figure 16 A observes the figure that the spot intensity of moving body when with the Z axle being the sense of rotation generation displacement of turning axle distributes from the Z1 direction.

Figure 16 B observes the figure that the spot intensity of moving body when with the Z axle being the sense of rotation generation displacement of turning axle distributes from the Z1 direction.

Figure 16 C observes the figure that the spot intensity of moving body when with the Z axle being the sense of rotation generation displacement of turning axle distributes from the Z1 direction.

Figure 16 D observes the figure that the spot intensity of moving body when with the Z axle being the sense of rotation generation displacement of turning axle distributes from the Z1 direction.

Figure 16 E observes the figure that the spot intensity of moving body when with the Z axle being the sense of rotation generation displacement of turning axle distributes from the Z1 direction.

Figure 17 A observes the figure that the spot intensity of moving body when with the Y-axis being the sense of rotation generation displacement of turning axle distributes from the X1 direction.

Figure 17 B observes the figure that the spot intensity of moving body when with the Y-axis being the sense of rotation generation displacement of turning axle distributes from the X1 direction.

Figure 17 C observes the figure that the spot intensity of moving body when with the Y-axis being the sense of rotation generation displacement of turning axle distributes from the X1 direction.

Figure 18 A be will be positioned at the spot intensity at center of Figure 17 A figure that distributes and amplify.

Figure 18 B be will be positioned at the spot intensity at center of Figure 17 B figure that distributes and amplify.

Figure 18 C be will be positioned at the spot intensity at center of Figure 17 C figure that distributes and amplify.

Figure 19 A observes the figure that the spot intensity of moving body when with the Y-axis being the sense of rotation generation displacement of turning axle distributes from the Y1 direction.

Figure 19 B observes the figure that the spot intensity of moving body when with the Y-axis being the sense of rotation generation displacement of turning axle distributes from the Y1 direction.

Figure 19 C observes the figure that the spot intensity of moving body when with the Y-axis being the sense of rotation generation displacement of turning axle distributes from the Y1 direction.

Figure 20 A be will be positioned at the spot intensity at center of Figure 19 A figure that distributes and amplify.

Figure 20 B be will be positioned at the spot intensity at center of Figure 19 B figure that distributes and amplify.

Figure 20 C be will be positioned at the spot intensity at center of Figure 19 C figure that distributes and amplify.

Figure 21 is used for illustrating the figure of moving body with respect to the detection method of benchmark grid when the X-direction generation displacement.

Figure 22 is used for illustrating that moving body is the figure of the detection method of turning axle when rotation has taken place with the Y-axis with respect to the benchmark grid.

Figure 23 is the figure that is used for illustrating the detection method when moving body is the turning axle rotation with respect to the benchmark grid with the Z axle.

Figure 24 is the stereographic map of modification of the benchmark grid of expression one embodiment of the present invention.

Figure 25 is the exploded perspective view of the table apparatus of expression one embodiment of the present invention.

Figure 26 is the stereographic map that part is cut the table apparatus of the state after representing to assemble.

Figure 27 is the figure of schematic configuration of the table apparatus of the expression pick-up unit that is applicable to one embodiment of the present invention.

Figure 28 is the stereographic map of structure of the transmission-type pick-up unit of expression one embodiment of the present invention.

Figure 29 amplifies the stereographic map of expression with the situation that multi-beam is radiated on the detection faces of transparent body angle grid.

Figure 30 is the figure from the structure of the transmission-type pick-up unit of directions X observation Figure 28.

Figure 31 amplifies the figure of expression with an example of the comb mesh pattern of beam-splitter.

Figure 32 is that the sensitive surface that will dispose a plurality of photodiodes amplifies the figure of expression.

Figure 33 is position (x, y) figure of the model on that expression light incides transparent body angle grid.

Figure 34 is intensity distributions I (x, the curve map of analog result y) of the transmission-type pick-up unit of expression Figure 28.

Figure 35 is cut apart the figure that PD55 amplifies expression with 4.

Figure 36 is used for illustrating the figure of method that also can obtain the rotation of θ z direction according to the relative position relation of X, Y displacement.

Figure 37 is the figure that is used for illustrating the configuration of a plurality of photodiodes in the light accepting part.

Figure 38 is the figure of method of displacement that is used for illustrating the directions X of the transmission-type pick-up unit that detects Figure 28.

Figure 39 is the figure of detection principle of detection method of XY position that is used for illustrating the transmission-type pick-up unit of Figure 28.

Figure 40 is the figure of variation of optical system of the transmission-type pick-up unit of expression Figure 28.

Figure 41 is the stereographic map of structure of the reflection-type pick-up unit of expression one embodiment of the present invention.

Figure 42 is the figure that expression is attached to the model of the transparent body angle grid on the reflecting surface of reflection-type pick-up unit of Figure 41.

Figure 43 is the be reflected figure of model of face reflex time former state transmission of the light of reflection-type pick-up unit of hypothesis Figure 41.

Figure 44 is the figure of structure of optical system of the reflection-type pick-up unit of expression Figure 41.

Figure 45 is the stereographic map of structure of reflection-type pick-up unit of the use reflecting surface angle grid of expression one embodiment of the present invention.

Figure 46 is the figure of model of reflecting surface angle grid of the reflection-type pick-up unit of expression Figure 45.

Figure 47 is the figure of structure of optical system of the reflection-type pick-up unit of expression Figure 45.

Figure 48 is the figure that is illustrated in the structure of the optical sensor unit that uses in the reflection-type pick-up unit of one embodiment of the present invention.

Symbol description

10,110,230 table apparatus; 12,111,231 pedestals; 14 the 1st; 16 the 2nd; 112,236; 113 scale portions; 114,290 pick-up units; 115 directions X magnet; 116 Y direction magnet; 117 yokes; 118 liners; 119 Z direction magnet; 120A, 120B directions X linear motor structure portion; 121A, 121B directions X coil; 122A, 122B directions X core; 124,249,300 pick-up units; 125A, the linear motor structure of 125B Y direction portion; 126A, 126B Y direction coil; 127A, 127B Y direction core; 130 Z direction electromagnets; 131 Z direction coils; 132Z direction core; 133 mounting substrates; 140,320,100 benchmark grids; 141 base portions; 18,20,24 linear motors; 22 transmission-type pick-up units; 28 control device; 30,102 transparent body angle grids; 32 transparency carriers; 34 illuminating parts; 34a LASER Light Source (LD); 36 light accepting parts; 38 beam-splitters; 51～59 photodiodes; 70 reflection-type pick-up units; 74 substrates; 76,100 optical sensor unit; 78 beam-deflection separation vessels (PBS); 92 reflecting surface angle grids.

Embodiment

Utilize accompanying drawing to describe in detail and be used for implementing embodiments of the present invention.

With reference to Fig. 3 and Fig. 4, the situation that the pick-up unit of one embodiment of the present invention is applied in the table apparatus describes for example.Table apparatus 230 is to have the device that planar motors is the SAWYER motor as drive unit.Fig. 3 is the cut-open view of table apparatus that expression possesses the pick-up unit of one embodiment of the present invention, and Fig. 4 is the vertical view corresponding to the structure division of area B shown in Figure 3.

Table apparatus 230 is made of pedestal 231, platform 236 and pick-up unit 249 substantially.On the surface of pedestal 231, be formed with a plurality of protuberances 232 with predetermined spacing.This predetermined spacing is the least unit when platform 236 is moved.In addition, pedestal 231 is by the metal manufacturing of iron etc.Platform 236 is made of movable table portion 237, fixed station portion 239, chuck 241, directions X driver 242A, 242B, Y direction driver 243A, 243B and pitch drives portion 245 substantially.

Movable table portion 237 is the base parts that driven by directions X driver 242A, 242B and Y direction driver 243A, 243B.As shown in Figure 4, below movable table portion 237, be equipped with directions X driver 242A, 242B and Y direction driver 243A, 243B, form the space at central portion. Directions X driver 242A, 242B and Y direction driver 243A, 243B are made of a plurality of coil portions 244 and air bearing 238 respectively.By this coil portion 244 is applied electric current, in coil portion 244, produce magnetic force, produce propelling power and drive movable table portion 237.

Air bearing 238 is to be used for the parts that strength by air makes directions X driver 242A, 242B and Y direction driver 243A, 243B float with respect to pedestal 231.By this air bearing 238 is set, with movable table portion 237 to directions X or Y direction or when the sense of rotation that with the Z axle is turning axle drives, can both move freely with respect to any direction.

Pitch drives portion 245 is located at respectively between directions X driver 242A, 242B and Y direction driver 243A, 243B and the movable table portion 237.Pitch drives portion 245 is used for carrying out centering, the horizontal level of movable table portion 237.Fixed station portion 239 is set in movable table portion 237 integratedly.Fixed station portion 239 drives the position that movable table portion 237 moves to expectation by utilizing directions X driver 242A, 242B and Y direction driver 243A, 243B.In fixed station portion 239, be equipped with the chuck 241 that is used for installing workpiece 248.

Here, with reference to Fig. 5 A to Fig. 5 D, the driving method of movable table portion 237 is described.Fig. 5 A～Fig. 5 D is the vertical view of relation of schematically representing the propelling power of the driving direction of movable table portion and directions X and Y direction driver.

Make movable table portion 237 under the situation that directions X moves, shown in Fig. 5 A, the coil portion 244 that is located among directions X driver 242A, the 242B is applied electric current, to produce the propelling power of directions X driver 242A, 242B relative to the directions X of wanting movable table portion 237 is moved.

Make movable table portion 237 under the situation that the Y direction moves, shown in Fig. 5 B, the coil portion 244 that is located among Y direction driver 243A, the 243B is applied electric current, the Y direction of wanting movable table portion 237 is moved is produced the propelling power of Y direction driver 243A, 243B.

In addition, be turning axle with the Z axle, movable table portion 237 is rotated under the situation about moving to E direction or D direction, the coil portion 244 that is located among directions X driver 242A, 242B and Y direction driver 243A, the 243B is applied electric current, to produce directions X driver 242A, 242B such shown in Fig. 5 C or Fig. 5 D and the propelling power of Y direction driver 243A, 243B.

And, when moving on the position of the expectation on the pedestal 231, stop to the applying of the electric current of coil portion 244, with the stationkeeping of fixed station portion 239 in fixed station portion 239.In addition, movable table portion 237 is that least unit moves with the spacing of the lip-deep protuberance 232 that is located at pedestal 231 as previously described.

Pick-up unit 249 is made of the testing agency 114 and the scale unit described later 233 of the bottom that is located at movable table portion 237.The function of the mensuration of the state of this pick-up unit 249 performances carrying out movable table portion 237.The what is called here " state ", comprise with the Z axle be the state that moves of the rotation of turning axle, the state that moves to directions X, be the state that moves of the rotation of turning axle with the X-axis, the state that moves to the Y direction and be the state that the rotation of turning axle is moved with the Y-axis, be the state of these 5 degree of freedom at least.Pick-up unit 249 is made of scale unit 233 and testing agency 114 substantially.

At first, with reference to Fig. 6 and Fig. 7 the scale unit in the pick-up unit 249 233 is described.Fig. 6 is the vertical view corresponding to the structure division of zone C shown in Figure 3, and Fig. 7 is the figure of expression scale portion and testing agency.Scale unit 233 is provided on the protuberance of being located on the pedestal 231 232.Scale unit 233 is made of scale portion 113, upper resin 252 and bottom resin 253.Scale portion 113 is made of base portion 141 and benchmark grid 140.

On base portion 141, be on the 2 dimension directions of X-Y direction in character about angle, be provided with a plurality of benchmark grids 140 that change by known function (being the set of the peak and valley of sine wave in this embodiment) with predetermined spacing F.On the upper surface of scale portion 113, be provided with upper resin 252, on the lower surface of scale portion 113, be provided with bottom resin 253.Upper resin 252 and bottom resin 253 are used for preventing that scale portion 113 is subjected to external force and damages.In addition, in upper resin 252, use optical transmission material preferably.

Then, with reference to Fig. 3 to Fig. 4 the testing agency 114 that constitutes pick-up unit 249 is described.Testing agency 114 is for being provided in by the structure in the space of the bottom surface sections of the movable table portion 237 of directions X driver 242A, 242B and Y direction driver 243A, 243B encirclement.

Like this, by bottom surface sections testing agency 114 is set in the movable table portion 237 of the position of approaching benchmark grid 140, compare the influence of the interference that can not be vulnerable to waving of air etc. with laser interferometer in the past, can access the position of correct fixed station portion 239.

Fig. 8 is the schematic configuration of expression testing agency and the figure of scale portion.Testing agency 114 be substantially have light source portion 330, beam-splitter 332, beam-deflection separation vessel 334,1/4 wavelength plate 336, boundling be with the structure of lens 338 and photo detector 339.Light source portion 330 is the parts that are used for shining the light 331 with width.Beam-splitter 332 is arranged on from the direct of travel side of the light 331 of light source portion 330 irradiation (among Fig. 8 below).

Fig. 9 is the vertical view of beam-splitter.As shown in Figure 9, in the present embodiment, on beam-splitter 332, be formed with peristome 341A～341I with lattice-shaped.Beam-splitter 332 is that being used for by peristome 341A～341I will be the parts of 9 bundle light 333 from light 331 beam split of light source portion 330 irradiations.

Peristome 341A～341I is formed on the surface of base portion 141 or in the face, makes it become the spacing F identical with the benchmark grid that sets with predetermined spacing F 140.In addition, interfere mutually by 9 bundle light 333 of the peristome 341A～341I diffraction of beam-splitter 332, on benchmark grid 140 with benchmark grid 140 set spacing uniformly-spaced or the interval that sets the integral multiple of spacing generate many hot spots.

Beam-deflection separation vessel 334 is located between beam-splitter 332 and the scale portion 113.Beam-deflection separation vessel 334 is to be used for making reflected light 337 by the surface reflection of benchmark grid 140 towards the device of boundling with lens 338.Boundling is located between beam-deflection separation vessel 334 and the photo detector 339 with lens 338, is used for reflected light 337 at photo detector 339 boundlings.

Then, with reference to Figure 10 photo detector 339 is described.Figure 10 is the figure that observes testing agency shown in Figure 8 from the direction shown in the arrow G.In addition, in Figure 10, reach the reflected light 337A～337I of each photodiode by the circle expression of single-point line expression.Photo detector 339 has the structure that is equipped with photodiode 350A～350H and photodiode 351～354 on its sensitive surface 339A.

Photodiode 350A～350H and photodiode 351～354th are used for reflected light 337A～337I is subjected to simultaneously the element of light.Photo detector 339 is used for detecting the state of fixed station portion 239 with respect to benchmark grid 140 according to being subjected to the variation of reflection of light light 337A～337I simultaneously, particularly being intensity and the photodiode 350A～350H of irradiation reflected light 337A～337I and the position of photodiode 351～354 according to reflected light 337A～337I.

Sensitive surface 339A is the face to reflected light 337A～337I sensitive side.Sensitive surface 339A is foursquare shape roughly, and heart portion is equipped with 4 photodiode 350E～350H therein.

Near 4 bights of sensitive surface 339A, be formed with photodiode 351～354.Particularly, set in the upper left bight of sensitive surface 339A shown in Figure 10 respectively photodiode 351, set photodiode 352 in the bight, lower-left of sensitive surface 339A, set photodiode 353 in the bight, bottom right of sensitive surface 339A, set photodiode 354 in the upper right bight of sensitive surface 339A.

Photodiode 351 constitutes by photodiode 351I, the 351J combination with shape triangular in shape, and photodiode 352 constitutes by photodiode 352L, the 352K combination with shape triangular in shape.In addition, photodiode 353 constitutes by photodiode 353M, the 353N combination with shape triangular in shape, and photodiode 354 constitutes by photodiode 354O, the 354P combination with shape triangular in shape.

Photodiode 350A is located at the centre position on the line that connects photodiode 351 and photodiode 352, and photodiode 350B is located at the centre position on the line that connects photodiode 352 and photodiode 353.In addition, photodiode 350C is located at the centre position on the line that connects photodiode 353 and photodiode 354, and photodiode 350D is located at the centre position on the line that connects photodiode 351 and photodiode 354.

As shown in figure 10, also shine reflected light 337A～337D or reflected light 337F～337I arbitrary group for each photodiode of photodiode 351～354 and photodiode 350A～350D.In this embodiment, be subjected to the variation of the position of reflection of light light 337A～337I, carry out the status detection of fixed station portion 239 according to photo detector 339.In addition, narrate in the back for concrete status detection method.

Then, to utilizing benchmark grid 140, can describing by the analog result that the status detection that above-mentioned photo detector 339 carries out 5 degree of freedom is carried out in order to confirm.

Figure 11 is the figure that is illustrated in the model of the testing agency that uses in the simulation.In addition, in Figure 11, the inner structure of testing agency 114 is arranged and schematically expression along rectilinear direction.In addition, in Figure 11, give identical label for the structure division identical with testing agency shown in Figure 8.

At first, obtain the spot intensity distribution of the reflected light of observing by photo detector 339 337 by calculating formula.At this moment, with testing agency 114 separately, the function combination of this each component parts is calculated by each structure member.Particularly, as shown in figure 11, can be divided into beam-splitter 332, benchmark grid 140, boundling usefulness lens 338, photo detector 339 and the space between them.

(x y) equals 1 to the corrugated function g of beam-splitter 332 in peristome 341A～341I, equal 0 in the zone beyond peristome 341A～341I.(x y) is represented by formula (1) this corrugated function g.

[formula 1]

$g(x,y)=\left\{\begin{array}{c}1\\ 0\end{array}\right....\left(1\right)$

Then, (x y) describes to the phase function G of benchmark grid 140.The light 333 that incides benchmark grid 140 becomes reflected light 337 and gets back to original light path.So, as shown in figure 12, the light paths of 9 bundle light 333 and reflected light 337 can be made as 1 direction, consider benchmark grid 140 phase function G (x, y).

Figure 12 is the figure that is used for illustrating the phase function of benchmark grid.If establish benchmark grid 140 be shaped as h (x, y), then incide point (x, light 333 y) is compared with the light of the some t ' on the base of inciding benchmark grid 140, optical path length only shorten 2h (x, y).Thus, (x y) is represented by formula (2) the phase function G of benchmark grid 140.Here, in formula (2), k represents the wave number of light, and A represents the amplitude of benchmark grid 140, and P represents the wavelength of benchmark grid 140.

[formula 2]

$h(x,y)=A\cos \left(\frac{2\mathrm{\πx}}{P}\right)+A\cos \left(\frac{2\mathrm{\πy}}{P}\right)$

G(x，y)＝exp[i2kh(x，y)]

……(2)

Then, (x y) is represented by formula (3) the phase function L of boundling usefulness lens 338.Here, in formula (3), f represents the focal length of boundling with lens 338.Boundling has according to the incident position with lens 338 and changes the function that phase place is carried out optically focused.

[formula 3]

Spatial transmission to light describes.The spatial transmission of light is by fresnel diffraction and by modelling.If establish the light wave at sightingpiston place and be u (x, y), the light wave of propagating beginning face is u ₀(x y), the distance from beginning face to sightingpiston is z, represents that then (x y) is represented by formula (4) for the u of the light wave at sightingpiston place.

[formula 4]

$u(x,y)=F^{-1}[\frac{i}{\mathrm{\&lambda;}}\&CenterDot;F[u_0(x,y)]\&CenterDot;F[\frac{e^{-\mathrm{<figure-callout\; id="2"\; label="ik\; z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{z^{}}\sqrt{{}^2+x^2+y^2}}}{\sqrt{{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}}^2+x^2+y^2}}\left]\right]...\left(4\right)$

Here, F[v (x, y)] be v (x, y) 2 the dimension Fourier transforms.λ is a light wavelength.

As shown in figure 11, the component part of optical system is arranged in a straight line, and the complex amplitude that the light on the beam-splitter 332 is incided in definition is U _A(x, y), the complex amplitude of (photodiode 350A～350H last and photodiode 351～354 on) is U on the photo detector 339 _D(x, y), the Z that is spaced apart of beam-splitter 332 and benchmark grid 140 ₁, benchmark grid 140 and the be spaced apart Z of boundling with lens 338 ₂(=f).At this moment, (x y) can obtain as following formula (5) spot intensity distribution I.

[formula 5]

u _A′(x，y)＝u _A(x，y)·g(x，y)

$u_B(x,y)=F^{-1}[\frac{i}{\mathrm{\&lambda;}}\&CenterDot;F[u_A^{\&prime;}(x,y)]\&CenterDot;F[\frac{e^{-\mathrm{<figure-callout\; id="0"\; label="ik\; z"\; filenames="A20058002142100631.png,A20058002142100632.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{{z_{}}^{}}\sqrt{{{}_0}^2+x^2+y^2}}}{\sqrt{{{\mathrm{<figure-callout\; id="0"\; label="z"\; filenames="A20058002142100631.png,A20058002142100632.png"\; state="\{\{state\}\}">z</figure-callout>}}_0}^2+x^2+y^2}}\left]\right]$

u _B′(x，y)＝u _B(x，y)·G(x，y)

$u_C(x,y)=F^{-1}[\frac{i}{\mathrm{\&lambda;}}\&CenterDot;F[u_B^{\&prime;}(x,y)]\&CenterDot;F[\frac{e^{-\mathrm{ik}\sqrt{{z_1}^2+x^2+y^2}}}{\sqrt{{z_1}^2+x^2+y^2}}\left]\right]$

u _C′(x，y)＝u _C(x，y)·L(x，y)

$u_D(x,y)=F^{-1}[\frac{i}{\mathrm{\&lambda;}}\&CenterDot;F[u_C^{\&prime;}(x,y)]\&CenterDot;F[\frac{e^{-\mathrm{<figure-callout\; id="2"\; label="ik\; z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{{z_{}}^{}}\sqrt{{{}_2}^2+x^2+y^2}}}{\sqrt{{{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}}_2}^2+x^2+y^2}}\left]\right]$

I(x，y)＝|u _D(x，y)| ²

……(5)

Then, (x, variation y) describes the spot intensity distribution I when benchmark grid 140 having been produced 5 degree of freedom mobile.If each displacement of establishing with respect to X-direction and Y direction is Δ x, Δ y, with the Z axle be turning axle to rotate anglec of rotation when mobile be θ z (deflection angle), with the X-axis be turning axle to rotate anglec of rotation when mobile be θ x (rotation angle), be that the anglec of rotation that turning axle rotates when mobile is θ y (pitch angle) with the Y-axis, then can obtain following formula (6).

[formula 6]

G(x，y)＝exp[i2k{h(x′+Δx，y′+Δy)+θ _y·x+θ _x·y}]

$\left[\begin{array}{c}{x}^{\&prime;}\\ y^{\&prime;}\end{array}\right]=\left[\begin{array}{cc}{\cos \mathrm{\&theta;}}_z& {-\sin \mathrm{\&theta;}}_z\\ {\sin \mathrm{\&theta;}}_z& {\cos \mathrm{\&theta;}}_z\end{array}\right]\&CenterDot;\left[\begin{array}{c}x\\ y\end{array}\right]...\left(6\right)$

I (x, variation y) in the time of can obtaining the motion that in benchmark grid 140, has produced 5 degree of freedom by calculating in formula (6) the substitution formula (5).I during the motion that produced 5 degree of freedom in benchmark grid 140 (x, represented by following formula (7) by variation y).

[formula 7]

$I_A(x,y)=\sqrt{{r_y}^2-{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}\&CenterDot;\exp [-\frac{x^2}{2{{\mathrm{\&sigma;}}_x}^2}-\frac{{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}{2{{\mathrm{\&sigma;}}_y}^2}]...\left(7\right)$

Figure 13 is that spot intensity distribution I (x, the result's of variation y) figure have been simulated in expression.In addition, the X1 direction indication is with respect to the direction of X-axis quadrature, and the Y1 direction indication is with respect to the direction of Y-axis quadrature, the direction of Z1 direction indication and X1, Y1 direction quadrature.

Then, with reference to the analog result shown in Figure 14 A to Figure 15 E, the variation that the spot intensity when moving body on X-direction displacement is taken place with respect to benchmark grid 140 distributes describes.Figure 14 A～Figure 14 E observes the figure that moving body (movable table 237) distributes with respect to the spot intensity of benchmark grid when displacement takes place X-direction from X1 direction (with reference to Figure 13).Figure 15 A～Figure 15 E observes the figure that moving body distributes with respect to the spot intensity of benchmark grid when displacement takes place X-direction from Y1 direction (with reference to Figure 13).

Shown in Figure 14 A to Figure 14 E, as can be known when displacement takes place in moving body on X-direction, the size variation of the spot intensity distribution 370A of the both sides of the spot intensity distribution 370C that is positioned at the center from spot intensity distribution 370A～370E that the X1 direction is observed, 370B, 370D, 370E.

On the other hand, shown in Figure 15 A to Figure 15 E, when observing spot intensity distribution 371A～371E from the Y1 direction,, in the size of 5 spot intensity distribution 371A～371E, also can't see variation even variation has taken place Δ x (displacement of X-direction).

Can infer by above-mentioned analog result, when displacement takes place in moving body on X-direction, spot intensity distribution 370A, 370B, 370D, 370E can carry out moving body by monitoring with respect to the displacement of X-direction and the detection of position (coordinate) from the X1 direction.

Particularly, as can be known when displacement takes place in moving body on X-direction, two photodiode 350A, the 350C (with reference to Figure 10) that are located on the sensitive surface 339A by supervision are distributed by the spot intensity of reflection of light light 337D, 337F, and can detect displacement and position (coordinate) of moving body with respect to X-direction.

In addition, though do not illustrate, but, when moving body on Y direction displacement takes place, can change from the size that the Y1 direction is judged two (adding up to 4) spot intensities distributions that are in the both sides that 5 spot intensities spot intensities that are positioned at the center distributing distribute according to analog result.Thus, when displacement takes place in moving body on Y direction, by being located at two photodiode 350B, 350D (with reference to Figure 10) the supervision reflected light 337B on the sensitive surface 339A, the spot intensity of 337D, can detect displacement and position (coordinate) of moving body with respect to Y direction.

Then, with reference to the analog result shown in Figure 16 A to Figure 16 E, the variation that the spot intensity when displacement (rotation is moved) is taken place on the sense of rotation that with the Z axle is turning axle moving body distributes describes.Figure 16 A to Figure 16 E observes the figure that the spot intensity of moving body when with the Z axle being the sense of rotation generation displacement of turning axle distributes from Z1 direction (with reference to Figure 13).In addition, in Figure 16 A to Figure 16 E, θ z represents deflection angle (is the angle of turning axle with the Z axle).

Shown in Figure 16 C, as can be known under the situation of θ z=Oarcsec, be that the center turns clockwise neither with the position of the peak value 337E of central authorities by the position of reflected light 337A, the 337C of 4 corner reflections, 337G, 337I, be not rotated counterclockwise yet.

In addition, shown in Figure 16 A and Figure 16 B, being under axial rotary negative direction (counterclockwise) the rotation situation about moving with the Z axle at moving body as can be known, is that the center is rotated counterclockwise by the position of reflected light 337A, the 337C of 4 corner reflections, 337G, 337I with the position of the reflected light 337E of central authorities.

In addition, shown in Figure 16 D and Figure 16 E, being under axial rotary positive dirction (clockwise direction) the rotation situation about moving with the Z axle at moving body as can be known, is that the center turns clockwise by the position of reflected light 337A, the 337C of 4 corner reflections, 337G, 337I with the position of the reflected light 337E of central authorities.And then, because reflected light 337A, the 337C shown in Figure 16 A to Figure 16 E, each position difference of 337G, 337I, so as can be known by monitoring from the Z1 direction and the position of reflected light 337A, 337C, 337G, 337I can carry out the detection of position, amount of movement and the anglec of rotation etc. of the moving body of moving body when with the Z axle being the sense of rotation generation displacement of turning axle by being located at photodiode 351～354 (with reference to Figure 10) on four jiaos of sensitive surface 339A.

Then, with reference to the analog result shown in Figure 17 A to Figure 20 C, the variation that the spot intensity of moving body when with the Y-axis being the sense of rotation generation displacement (rotation is moved) of turning axle distributed describes.Figure 17 A to Figure 17 C observes the figure that the spot intensity of moving body when with the Y-axis being the sense of rotation generation displacement of turning axle distributes from X1 direction (with reference to Figure 13).Figure 18 A to Figure 18 C be will be positioned at the spot intensity at center of Figure 17 A to Figure 17 C figure that distributes and amplify.In addition, Figure 19 A to Figure 19 C observes the figure that the spot intensity of moving body when with the Y-axis being the sense of rotation generation displacement of turning axle distributes from Y1 direction (with reference to Figure 13).Figure 20 A to Figure 20 C be will be positioned at the spot intensity at center of Figure 19 A to Figure 19 C figure that distributes and amplify.In addition, in Figure 17 A to Figure 20 C, θ y represents pitch angle (is the angle of turning axle with the Y-axis).

Shown in Figure 18 A to Figure 18 C, when moving body with the Y-axis is axial rotary positive dirction (clockwise direction) generation displacement (rotation is moved), move to the left side of Figure 18 A the position of the X-direction of the spot intensity distribution 375C that sees from the X1 direction, when moving body is axial rotary negative direction (counterclockwise) when displacement (rotation) takes place with the Y-axis, move to the right side of Figure 18 C the position of the X-direction of the spot intensity distribution 375C that sees from the X1 direction.

On the other hand, shown in Figure 20 A to Figure 20 C, when moving body with the Y-axis was turning axle generation displacement (to the rotation of positive dirction and negative direction), the position of the Y direction of the spot intensity distribution 380C that sees from the Y1 direction did not change fully.In addition, when spot intensity distribution 375C when X-direction moves, hot spot distribution intensity distribution 375A, 375B also move integratedly.

Hence one can see that, when moving body when with the Y-axis being the sense of rotation generation displacement of turning axle, the position (position of reflected light 337E) of the X-direction by monitoring the spot intensity distribution 375C that observes from the X1 direction by 4 photodiode 350E～350H (with reference to Figure 10) at the center that is located at sensitive surface 339A, and can detect the anglec of rotation around Y-axis of moving body.

In addition, by not shown analog result as can be known, when moving body when with the X-axis being the sense of rotation generation displacement of turning axle, also can be by monitoring the position that is subjected to the Y direction of reflection of light light 337E (spot intensity distribution 375C) by 4 photodiode 350E～350H at the center that is located at sensitive surface 339A, detect moving body around the anglec of rotation θ of X-axis x (rotation angle).

Then, with reference to Figure 21 to Figure 23,, the status detection method of moving body is described according to above-mentioned analog result.Figure 21 is used for illustrating the figure of moving body with respect to the detection method of benchmark grid when the X-direction generation displacement.In addition, in Figure 21, spot intensity distribution 385D represents to distribute corresponding to the spot intensity of reflected light 337D, and spot intensity distribution 385F represents to distribute corresponding to the spot intensity of reflected light 337F.

As shown in figure 21, if moving body moves on X-direction with respect to benchmark grid 140, then photodiode 350A, 350C are subjected to the spot intensity distribution 385D of reflection of light light 337D, 337F, the size variation of 385F.Here, be output as I if establish photodiode 350A _350A, establish photodiode 350C and be output as I _350C, then moving body can be by S with respect to the displacement Δ X of the X-direction of benchmark grid 140 _X=(I _350C-I _350A)/(I _350C+ I _350A) obtain.In addition, moving body with respect to benchmark grid 140 under situation about moving on the Y direction, be output as I if establish photodiode 350B _350B, establish photodiode 350D and be output as I _350D,, then moving body can be by S with respect to the displacement Δ Y of the Y direction of benchmark grid 140 _Y=(I _350D-I _350B)/(I _350D+ I _350B) obtain.

Figure 22 is the figure that is used for illustrating the detection method when moving body is the turning axle rotation with respect to the benchmark grid with the Y-axis.In addition, in Figure 22, spot intensity distribution 385E represents to distribute corresponding to the spot intensity of reflected light 337E.As shown in figure 22, if moving body is the turning axle rotation with the Y-axis with respect to benchmark grid 140, then integrally move along X-direction corresponding to the positions of spot intensity distribution 385D～385E of 3 bundle reflected light 337D～337F.The amount of movement of this moment is followed autocollimation method.This amount of movement can be by being located at sensitive surface 339A 4 the photodiode 350E～350H at center detect.

Here, be output as I if establish photodiode 350E _350E, establish photodiode 350F and be output as I _350F, establish photodiode 350G and be output as I _350G, establish photodiode 350H and be output as I _350H, then can be by S _QY=(I _350G+ I _350H-I _350E-I _350F)/(I _350E+ I _350F+ I _350G+ I _350H) obtain the amount of movement of X-direction, can obtain θ y (pitch angle) according to the amount of movement of the X-direction of obtaining.

Equally, can be by S _QX=(I _350F+ I _350G-I _350E-I _350H)/(I _350E+ I _350F+ I _350G+ I _350H) obtain the amount of movement of Y direction, can obtain θ x (angle of pitch) according to the amount of movement of the Y direction of obtaining.

Figure 23 is the figure that is used for illustrating the detection method when moving body is the turning axle rotation with respect to the benchmark grid with the Z axle.If moving body is turning axle rotation with respect to benchmark grid 140 with the Z axle, then as illustrating among above-mentioned Figure 16 A to Figure 16 E, the position of 4 reflected light 337A, 337C, 337G, 337I is that the center rotates with the position of the reflected light 337E of central authorities.

Here, be output as I if establish photodiode 351I _351I, establish photodiode 351J and be output as I _351J, establish photodiode 351K and be output as I _351K, establish photodiode 351L and be output as I _351L, establish photodiode 351M and be output as I _351M, establish photodiode 351N and be output as I _351N, establish photodiode 351O and be output as I _351O, establish photodiode 351P and be output as I _351P, then can be by S _QZ={ (I _351J+ I _351L+ I _351N+ I _351P)-(I _351I+ I _351K+ I _351M+ I _351O)/(I _351I+ I _351J+ I _351K+ I _351L+ I _351M+ I _351N+ I _351O+ I _351P) obtain rotation amount, can obtain θ z (deflection angle) according to the value of this rotation amount.

Making from the light beam split of light source portion 330 irradiations by beam-splitter 332 is that multi-beam 333 is radiated on the benchmark grid, by multi beam reflected light 337 is subjected to light simultaneously by the photodiode 350 of multicomponent type, can carry out the status detection of 5 degree of freedom of moving body.In addition, owing to detect the state of moving body according to the variation of multi beam reflected light 337, even so when illuminated some defectiveness in the benchmark grid 140 of multi-beam 337, also can carry out status detection according to the variation of the multi beam reflected light 337 of never defective benchmark grid 140 reflections.Therefore, compare, can carry out status detection accurately with 1 bundle rayed is carried out status detection on the benchmark grid, according to its reflected light situation in the past.

In addition, in the testing agency 114 of this embodiment,,, can realize the reduction of the cost of testing agency 114 so can make simplifying the structure of photo detector 339 owing to do not use the detection of the such autocollimation method of conventional art.

In addition, in the present embodiment,, also can use CCD to replace photodiode 351～354 and photodiode 350A～350D though used the photo detector 339 that is provided with photodiode 351～354 and photodiode 350A～350D.Under the situation of using CCD, also can access the effect identical with present embodiment.

Then, with reference to Figure 24 the modification of the benchmark grid of present embodiment is described.Figure 24 is the stereographic map of modification of the benchmark grid of expression present embodiment.The benchmark grid 400 of Figure 24 alternately disposes the recess 402 of foursquare cylindrical portion 401 roughly and the square shape identical with cylindrical portion 401 along two direction of principal axis in the face and forms.As the benchmark grid of present embodiment, also can use the benchmark grid 400 of roughly square shape as shown in Figure 24.The PV value that makes benchmark grid 400 is 0.08 μ m.

Then, with reference to Figure 25 and Figure 26, the table apparatus 10 of one embodiment of the present invention is described.Figure 25 is the exploded perspective view of the table apparatus of expression one embodiment of the present invention.Figure 26 is the stereographic map that part is cut the table apparatus of the state after representing to assemble.This table apparatus 110 is to be used for making the device that moves to the precalculated position as the wafer that is moved body in semiconductor manufacturing for example with in the steeper etc.

This table apparatus 110 is made of pedestal 111, platform 112, pick-up unit 124 and drive unit etc. substantially.Pedestal 111 is the parts as the base station of table apparatus 110, is equipped with the linear motor structure 120A of portion described later, 125A, Z direction electromagnet 130 and testing agency 114.In addition, the structure of the testing agency 114 of present embodiment is identical with testing agency 114 shown in Figure 3.

Platform 112 is mounted with on top as the wafer 60 of moving body and chuck 61, and is equipped with magnet 115,116, yoke 117 in the bottom, and the Z direction that sets via liner 118 magnet 119.This 112 is to carry out that the arrow X-direction moves among the figure, Y direction moves and be the structure that the rotation at center is moved with the Z axle with respect to pedestal 111.

As shown in figure 25, scale portion 113 is fixed on the substantial middle position at the back side (with pedestal 111 opposed faces) of platform 112.On the other hand, testing agency 114 is for being provided in the structure on the pedestal 111.Particularly, testing agency 114 is located on the mounting substrate 133 that is installed on the pedestal 111.

Then, drive unit is described.Drive unit is to make platform 112 carry out with respect to pedestal 111 that X-direction moves, Y direction moves and is the device that the rotation at center is moved with the Z axle.This drive unit is made of with magnet 119 etc. with magnet 116, Z direction with magnet 115, Y direction the directions X that is provided in the directions X linear motor structure 120A of portion, 120B on the pedestal 111, the linear motor structure 125A of portion of Y direction, 125B, Z direction electromagnet 130 and be provided on the platform 112.

The directions X linear motor structure 120A of portion is provided on the pedestal 111, is made of with core 122A with coil 121A-1,121A-2 (being called directions X coil 121A when both are unified) and directions X a pair of directions X.A pair of directions X is arranged setting on the arrow X-direction in the drawings with coil 121A-1,121A-2, makes and can distinguish the structure of supplying electric current single-handedly.

In addition, the directions X linear motor structure 120B of portion is and the identical structure of the directions X linear motor structure 120A of portion, is made of with core 122B with coil 121B (though not label, be made of with coil a pair of directions X) and directions X directions X.This directions X linear motor structure 120A of portion and the directions X linear motor structure 120B of portion clip the equipping position of above-mentioned testing agency 114 and the structure that disposes along arrow Y direction among the figure with leaving.

On the other hand, linear motor structure 125A of portion of Y direction and the linear motor structure 125B of portion of Y direction also are and the identical structure of the above-mentioned directions X linear motor structure 120A of portion.Promptly, the linear motor structure 125A of portion of Y direction by the Y direction with coil 126A (though do not give label, but constitute with coil by a pair of Y direction) and Y direction core 127A formation, the linear motor structure 125B of portion of Y direction is made of with core 127B with coil 126B (though do not give label, being made of with coil a pair of Y direction) and Y direction the Y direction.Linear motor structure 125A of portion of this Y direction and the linear motor structure 125B of portion of Y direction clip the equipping position of above-mentioned testing agency 114 and the structure that disposes along arrow X-direction among the figure with leaving.

Z direction electromagnet 130 floats with respect to pedestal 111 by making platform 112, plays the function that forms the gap between above-mentioned directions X is with magnet 115A and the magnet of being located on the platform 112 115,116 described later.This Z direction electromagnet 130 is made of with core 132 with coil 131 and Z direction the Z direction.In addition, to float stabilization in order making, and to be provided in respectively on the corner location of making rectangular-shaped pedestal 111.

In addition, the mechanism that platform 112 is floated with respect to pedestal 111 except the magnetic mechanism that uses in this embodiment, it is also conceivable that and uses compressed-air actuated method or the mechanism by a plurality of ball supporting bases 111 etc.

On the other hand, as mentioned above, on platform 112, be equipped with directions X magnet 115 and Y direction magnet 116.Though not expression in the drawings, that each magnet 115,116 is equipped with respectively is a pair of, add up to and be equipped with 4.Thereby under the state of bottom surface side observation platform 112, each magnet 115,116 interacts and is configured to roughly quadrilateral.

Directions X uses magnet 115 by a plurality of same permanent magnets are arranged with linearity so that a plurality of magnet row (aggregate of small magnet) of alternating polarity ground performance constitute.Equally, the Y direction with magnet 116 also by a plurality of same permanent magnets are arranged with linearity so that a plurality of magnet of alternating polarity ground performance are listed as constitutes.Top at each magnet 115,116 is equipped with yoke 117, and this yoke 117 plays a plurality of each magnet function of combination magnetically that will constitute each magnet 115,116.

In said structure, constitute, under the state that platform 112 is installed on the pedestal 111, a pair of directions X is positioned on the directions X linear motor structure 120A of portion with of magnet 115, and another directions X is positioned on the directions X linear motor structure 120B of portion with magnet 115.

In addition, constitute, under the state that platform 112 is installed on the pedestal 111, a pair of Y direction is positioned on the linear motor structure 125A of portion of Y direction with of magnet 116, and another is positioned at the Y direction and is positioned on the linear motor structure 125B of portion with magnet 116.

In addition, constitute, under the state that platform 112 is installed on the pedestal 111, and under the state that platform 112 is floated with respect to pedestal 111, each magnet 115,116 engages with the opposed linear motor structure 120A of portion in magnetic field, 120B, 125A, the 125B that produce.

And then under above-mentioned installment state, each magnet 115,116 is configured to, with respect to being located at each coil 121A, the 121B among each linear motor structure 120A of portion, 120B, 125A, the 125B, the coiling direction quadrature of 126A, 126B.

By drive unit is made said structure, the directions X linear motor structure 120A of portion, 120B and directions X interact with magnet 115 and play the function of platform 112 as the linear motor of the driving of arrow X-direction in figure.Equally, the linear motor structure 125A of portion of Y direction, 125B and Y direction interact with magnet 116 and play the function of platform 112 as the linear motor of the driving of arrow Y direction in figure.

That is in this embodiment, be the structure that on X, Y two directions, disposes each two groups of linear motor respectively.By this structure, can guarantee bigger space at the device middle body, pick-up unit 124 can be arranged on this position.In addition, in the present embodiment, made scale portion 113 is provided on the platform 112, testing agency 114 is provided in structure on the pedestal 111.This is because do not need scale portion 113 not to be connected distribution.But, also can make scale portion 113 is provided on the pedestal 111, testing agency 114 is located at structure on the platform 112.

In addition, in the above-mentioned drive unit that is configured, if only simultaneously to equidirectional driving directions X linear motor structure 120A of portion and the directions X linear motor structure 120B of portion, then platform 112 is along arrow X-direction translation motion among the figure.

Equally, if only simultaneously to linear motor structure 125A of portion of equidirectional driving Y direction and the linear motor structure 125B of portion of Y direction, then platform 112 is along arrow Y direction translation motion among the figure.

In addition, by each paired linear motor structure 120A of portion and 120B, 125A and 125B are driven respectively round about, platform 112 arrow Z axle in figure carries out rotatablely moving of θ Z.

Like this, by will being located at by the pick-up unit 124 that testing agency 114 and scale portion 113 constitute on the table apparatus 110, can be by the state of 5 degree of freedom of testing agency's 114 monitor stations 112.

In addition, in the above-described embodiment, lift to use to possess and tie up the structure of scale portion 113 that directions have the benchmark grid 140 of sine wave shape with respect to 2 and be illustrated as example.Perhaps, also can adopt to constitute and replace benchmark grid 140 for the benchmark grid 400 of the shape of symmetry with respect to the central shaft of benchmark grid 400.

In addition, above-mentioned embodiment not only can be applied in the semiconductor-fabricating device, can also be widely used in micromachine, IT will need in the field of trickle processing from now on light communication component etc.That is, present micromachine manufacturing technology is utilized semiconductor fabrication mostly, and the application of the invention can be made trickleer and various micromachine.And then, in the field of Laser Processing, require to have platform with the precision hypervelocity ground motion of ultra micro.

Then, Figure 27 is the figure of schematic configuration of the table apparatus of the expression pick-up unit that is applicable to one embodiment of the present invention.In addition, in the following description of this embodiment, the structure of transmission-type pick-up unit 22 described later for convenience of explanation and operating principle will be made as the Z direction to transparent body angle grid 30 irradiation directions of light, in Figure 27 left and right directions will be made as the Z direction and describe.

As shown in figure 27, table apparatus 10 have pedestal 12, be provided with movably with respect to pedestal 12 the 1st 14, be loaded on the 1st 14 and to the left and right the 2nd 16 of being provided with movably of direction, the two ends that drive the 1st 14 of going forward side by side a pair of linear motor (driving mechanism) 18,20, be configured in linear motor 18 near transmission-type pick-up unit 22, drive the 2nd 16 linear motor 24 and the straight-line detection position 26 that disposes abreast with linear motor 24.

Transmission-type pick-up unit 22 constitutes major part of the present invention, constitute as described later, with the 1st 14 shift position is main detected object, also can detect simultaneously as with respect to the above-below direction (Y direction) of the kinematic error reason of moving direction (directions X) direction in addition, around each angle θ x, θ y, θ z.

Be input in the control device 28 by coordinate converter 27 coordinate transforms by transmission-type pick-up unit 22 and X straight-line detection position 26 detected detection signals.Control device 28 has the arithmetical organ (control program) that calculates the controlled quentity controlled variable of supplying with to linear motor 18,20,24 according to predefined arithmetic expression, will export to each servoamplifier 29a～29c by the control signal that calculates.And, supplied with and driving linear motor 18,20,24 to linear motor 18,20,24 by the drive signal after each servoamplifier 29a～29c amplification.

In addition, in transmission-type pick-up unit 22, as described later, can detect the 1st 14 X, the displacement of Y direction and the angle of inclination of θ z direction.Therefore, by control device 28, can drive linear motor 18,20 according to going forward side by side accurately, so that can not tilt for the 1st 14 by the detection data of transmission-type pick-up unit 22 detected all directions.

Here, with reference to Figure 28 the structure of the transmission-type pick-up unit 22 that is used for the transmission-type surface encoder is described.

As shown in figure 28, transmission-type pick-up unit 22 have the transparent body angle grid (benchmark grid) 30 that on the 1st 14 moving direction, extends to form, with transparent body angle grid 30 remain plumbness transparency carrier 32, send the illuminating part 34 of multi beam directional light and the multi beam directional light of transmission transparent body angle grid 30 be subjected to the light accepting part 36 of light towards transparent body angle grid 30.

Transparency carrier 32 is made of transparent glass plate etc., is fixed on the pedestal 12 as fixation side with plumbness.And, on the surface of transparency carrier 32, be connected with transparent body angle grid 30.Transparent body angle grid 30 and transparency carrier 32 are owing to being formed by transparent material, so have from the character of the light meeting transmission of illuminating part 34 irradiations.

In addition, transparent body angle grid 30 is formed with detection faces 30a from the teeth outwards as amplifying expression among Figure 29, and this detection faces 30a alternately forms the concave curved surface and the convex surface of the solid of the profile with predetermined sinusoidal wave on 2 dimension directions.The concaveconvex shape of this detection faces 30a for example can evenly and accurately form trickle concave curved surface, convex surface by the pushing metal pattern.

Illuminating part 34 is set to the vertical direction on the surface of transparent body angle grid 30 opposed.In addition, light accepting part 36 is set to the vertical direction at the back side of transparent body angle grid 30 opposed.And illuminating part 34 and light accepting part 36 are supported integratedly by the carriage (not shown) on the 1st 14 that is fixed on as movable side, and be retained as via transparent body angle grid 30 and transparency carrier 32 and over against.

Therefore, if illuminating part 34 and light accepting part 36 are driven to the Y direction with the 1st 14, then become with respect to transparent body angle grid 30 and transparency carrier 32 and move.At this moment, the multi beam directional light that sends from illuminating part 34 is subjected to light by concave curved surface and convex surface refraction and the transmission of detection faces 30a by light accepting part 36.In light accepting part 36, as described later, be provided with a plurality of photo detectors that the multi beam directional light that sends from illuminating part 34 are subjected to light with predetermined space.And, according to the position of the concave curved surface of the transmittance detection faces 30a that comes self-luminescent part 34 and convex surface and refractive index changes, and can obtain illuminating part 34 and light accepting part 36 amount of movement according to the variation that is subjected to light intensity distributions of each light in light accepting part 36 with respect to transparent body angle grid 30.

Figure 30 is the pie graph from the structure of the transmission-type pick-up unit 22 of directions X observation Figure 28.

As shown in figure 30, the illuminating part 34 for example light beam split of the light source 34a of free laser diode in the future is multi beam (for example n=9 bar) directional light, and the foursquare beam-splitter 38 that has as the comb mesh pattern of spectrophotometric device is installed on the exit facet of light source 34a.

Figure 31 amplifies the figure of expression with an example of the comb mesh pattern of beam-splitter 38.As shown in figure 31, beam-splitter 38 forms lattice-shaped with 9 minute opening 38A～38I with predetermined interval LF on 2 dimensional planes of directions X and Y direction.It will be 9 bundle light 42 from light 40 beam split of light source 34a irradiation that beam-splitter 38 is used for by minute opening 38A～38I ₁～42 ₉

In addition, in Figure 31, act is provided with the structure of 9 minute opening 38A～38I on beam-splitter 38 example is illustrated, but can at random set for the configurable number and the interval of minute opening, for example also minute opening can be set 10 * 10 on directions X and Y direction.Thereby, can be set at quantity arbitrarily by the configurable number of selecting minute opening by the quantity of the light of beam-splitter 38 beam split (in other words, be radiated on the light accepting part 36 hot spot number).

Minute opening 38A～38I form be formed on detection faces 30a on concave curved surface and convex surface set the identical size of spacing F.In addition, 9 of the minute opening 38A～38I by beam-splitter 38 bundle light 42 ₁～42 ₉Become directional light and be radiated on the detection faces 30a of transparent body angle grid 30, thus with transparent body angle grid 30 set spacing F uniformly-spaced (perhaps the diffraction by by peristome 38A～38I the time and with the interval of the integral multiple that sets spacing F) generate many hot spots.

In addition, 9 of transmission transparent body angle grid 30 bundle light 42 ₁～42 ₉By object lens 44 optically focused of the front that is configured in light accepting part 36 to the sensitive surface 36a of light accepting part 36.

Shown in figure 32, on the sensitive surface 36a of light accepting part 36, be provided with 9 bundle light 42 to transmission transparent body angle grid 30 ₁～42 ₉Be subjected to the photodiode 51～59 of light.

Then, with reference to Figure 32 light accepting part 36 is described.The circle mark that is illustrated by the broken lines among Figure 32 has represented to arrive the light 42 of each photodiode 51～59 ₁～42 ₉Many hot spots.Be located at photodiode 51～59 outputs on the sensitive surface 36a of light accepting part 36 corresponding to light 42 ₁～42 ₉The detection signal that is subjected to light intensity.The photodiode 51,53,57,59 that is configured on four jiaos of sensitive surface 36a in the photodiode 51～59 2 is cut apart PD and is constituted by what made up a pair of photo detector, and the photodiode 55 that is configured in the central authorities of sensitive surface 36a 4 is cut apart PD and constituted by what made up 4 photo detectors.

Being configured in upper left 2 of sensitive surface 36a, to cut apart PD51 be that the photo detector (51a, 51b) that forms triangle is one group, detects light 42 ₁Light intensity, being configured in 2 of upper right bight, to cut apart PD53 be that the photo detector (53a, 53b) that forms triangle is one group, detects light 42 ₃Light intensity, be configured in the lower-left the bight 2 to cut apart PD57 be that the photo detector (57a, 57b) that forms triangle is one group, detect light 42 ₇Light intensity, be configured in the bottom right the bight 2 to cut apart PD59 be that the photo detector (59a, 59b) that forms triangle is one group, detect light 42 ₉Light intensity.

In addition, be configured in 4 the cutting apart PD55 and arrange and to be set to of central authorities of sensitive surface 36a, make 4 photo detector 55a～55d on directions X and Y direction, become each two row, detect by 4 photo detector 55a～55d and be radiated at 42 of central authorities ₅Light intensity.Be configured in sensitive surface 36a 4 limits the centre, photodiode 52,54,56,58 detects light 42 respectively ₂, 42 ₄, 42 ₆, 42 ₈Light intensity.In the present embodiment, according to by light accepting part 36 detected light 42 with above-mentioned 9 photodiodes 51～59 ₁～42 ₉The variation of intensity distributions, carry out the 1st 14 the position and the detection at angle of inclination.

Then, the analog result to transmission-type pick-up unit 22 describes.

In the model that uses transparent body angle grid 30, the surface configuration of the detection faces 30a of transparent body angle grid 30 is concave curved surface and the convex surface that makes sinusoidal wave 2 dimension ground stacks as the formula (8).

[formula 8]

$h(x,y)=-A_x\cos \left(2\mathrm{\&pi;}\frac{x}{P_x}\right)-A_y\cos \left(2\mathrm{\&pi;}\frac{x}{P_y}\right)...\left(8\right)$

Here, the spacing P of transparent body angle grid shape _x, P _yBe the following magnitudes of 100 μ m, amplitude A x, Ay are the following magnitude of 100nm, if light is incided wherein then bring into play the such effect of diffraction lattice.So, when setting up the model of pick-up unit 22, light is handled as ripple here, resolve by calculating amplitude, phase place.That is, used herein is not the model of geometrical optics but the model of wave optics.

As shown in figure 33, suppose light from the vertical direction of transparent body angle grid 30 generally perpendicularly incide the position (x, y).At this moment, if advance to face ∑ 2 from face ∑ 1, then light forward travel distance 2A-h only (x, y) after, in transparent body angle grid 30 only forward travel distance h (x, y), transmission transparent body angle grid 30.If establishing the refractive index of transparent body angle grid 30 is n, establish the outer refractive indexes of transparent body angle grid 30 is 1, then the optical path length L of this light when face ∑ 1 advances to face ∑ 2 represents like that suc as formula (9).

[formula 9]

L＝2A-h(x，y)+n·h(x，y) ……(9)

Owing to L is only arranged at optical path length when face ∑ 1 advances to face ∑ 2, thus phase delay it be multiply by wave number k (=2 π/λ, λ: the kL light wavelength).Thus, the phase function G that transparent body angle grid 30 is had (x, y) represent like that by formula described as follows (10).

[formula 10]

G(x，y)＝e ^-ikL

＝e ^{-ik{2A-h(x,y)+n·h(x,y)}}

＝e ^{-ik(n-1)h(x，y)}·e ^-i2kA ……(10)

Because constant term e ^-i2kAX can ignore, so (y) can represent suc as formula (11) G like this.

G(x，y)＝e ^{-ik(n-1)h(x，y)} ……(11)

During when the displacement that in transparent body angle grid 30, produces directions X, Y direction with around the rotation of Z axle, formula (11) can be showed as following formula (12).

[formula 11]

G(x，y)＝e ^{-ik(n-1)h(x′+Δx，y′+Δy)}

$\left[\begin{array}{c}{x}^{\&prime;}\\ y^{\&prime;}\end{array}\right]=\left[\begin{array}{cc}\cos {\mathrm{\&theta;}}_z& -{\sin \mathrm{\&theta;}}_z\\ \sin {\mathrm{\&theta;}}_z& \cos {\mathrm{\&theta;}}_z\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]...\left(12\right)$

It more than is the analog result of the model of transparent body angle grid 30.

Then, the optical system to the transmission-type pick-up unit 22 that uses transparent body angle grid 30 describes.

As shown in figure 30, in the optical system of transmission-type pick-up unit 22, from the directional light 42 of lasing light emitter (LD) 34a ejaculation ₁～42 ₉Incide on the beam-splitter 38 of lattice-shaped with minute opening 38A～38I.Light by each minute opening 38A～38I diffraction of beam-splitter 38 is interfered mutually, and on transparent body angle grid 30 with the opening of comb mesh pattern at interval identical distance generate the directional light 42 that crest is erect ₁～42 ₉(multi beam).Directional light 42 ₁～42 ₉Behind transmission transparent body angle grid 30, by object lens 44 optically focused to the sensitive surface 36a of light accepting part 36.

Intensity distributions on the sensitive surface 36a of the light accepting part 36 of obtaining this optical system is divided into optical system each key element here, uses the function that the term amplitude and the phase term of the light wave that each key element had are exerted one's influence.Employing according to these functions calculate successively ua, ua ' ..., ud method.This optical system is made of the light wave propagation space between light-emitting component 34, beam-splitter 38, transparent body angle grid 30, object lens 44 and each key element.

Next coming in order describe these functions.Suppose that illuminating part 34 sends the directional light ua that its intensity distributions meets Gaussian distribution.That is, directional light ua is the unified light wave of phase place in one side.Ignore phase term, be made as the value of the evolution of in term amplitude, getting the Gaussian distribution formula.The function of illuminating part 34 formula described as follows (13) defines like that.

[formula 12]

$\mathrm{ua}(x,y)=\sqrt{e^{\frac{x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}{2{\mathrm{\&sigma;}}^2}}}$ (wherein, σ=1200 μ m) ... (13)

Beam-splitter 38 makes the transmittance among each the minute opening 38A～38I that incides comb mesh pattern, and other light is blocked.(x y) is represented by following formula (14) the transmission function g of beam-splitter 38.

[formula 13]

The phase function of transparent body angle grid 30 as described above.

If object lens 44 have had incident plane wave then make it become the effect of spherical wave.(x y) is represented by formula (15) the phase function L of object lens 44.

[formula 14]

$L(x,y)=e^{\mathrm{ik}(\sqrt{{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">f</figure-callout>}}^2+x^2+y^2}-f)}...\left(15\right)$

The propagation in the space of light is considered with the formula of fresnel diffraction.The light that penetrates from face ∑ 1 propagates into to leave and only is the face ∑ 2 of distance z.At this moment, the formula of fresnel diffraction is represented by following formula (16).

[formula 15]

$u(x,y)={\&Integral;\&Integral;u}_0(x_0,y_0)\frac{{\mathrm{ie}}^{-\mathrm{<figure-callout\; id="2"\; label="ik\; z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{z^{}}\sqrt{{}^2+{(x-x_0)}^2+{(y-y_0)}^2}}}{\mathrm{\&lambda;}\sqrt{{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}}^2+{(x-x_0)}^2+{(y-y_0)}^2}}{\mathrm{<figure-callout\; id="0"\; label="dx"\; filenames="A20058002142100631.png,A20058002142100632.png"\; state="\{\{state\}\}">dx</figure-callout>}}_0{\mathrm{<figure-callout\; id="0"\; label="dy"\; filenames="A20058002142100631.png,A20058002142100632.png"\; state="\{\{state\}\}">dy</figure-callout>}}_0...\left(16\right)$

Here, u ₀(x ₀, y ₀) corrugated on the presentation surface ∑ 1, (i represents imaginary unit to u for x, the y) corrugated on the presentation surface ∑ 2, and λ represents light wavelength.

Formula (16) is a convolution integral, and that works is deformed into the form of using Fourier transform for formula described as follows (10).Here, F[v (x, y)] expression v (x, Fourier transform y), F ^-1[ω (x, y)] expression ω (x, inverse Fourier transform y).

[formula 16]

$u(x,y)=u_0(x,y)*\frac{{\mathrm{ie}}^{-\mathrm{<figure-callout\; id="2"\; label="ik\; z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{z^{}}\sqrt{{}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}}{\mathrm{\&lambda;}\sqrt{{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}$

$=F^{-1}\left[F\right[u_0(x,y)\&CenterDot;F\left[\frac{{\mathrm{ie}}^{-\mathrm{<figure-callout\; id="2"\; label="ik\; z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{z^{}}\sqrt{{}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}}{\mathrm{\&lambda;}\sqrt{{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}}^2+x^2+y^2}}\right]]...\left(17\right)$

According to more than, gather the model of transmission-type pick-up unit 22, obtain the sensitive surface 36a of light accepting part 36 intensity distributions I (x, y).(x y) is represented by following formula (18) the intensity distributions I of sensitive surface 36a.

[formula 17]

ua′(x，y)＝ua(x，y)·g(x，y)

$\mathrm{ub}(x,y)=F^{-1}\left[F\right[{\mathrm{ua}}^{\&prime;}(x,y)]\&CenterDot;F[\frac{{\mathrm{ie}}^{-\mathrm{<figure-callout\; id="0"\; label="ik\; z"\; filenames="A20058002142100631.png,A20058002142100632.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{{z_{}}^{}}\sqrt{{{}_0}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}}{\mathrm{\&lambda;}\sqrt{{{\mathrm{<figure-callout\; id="0"\; label="z"\; filenames="A20058002142100631.png,A20058002142100632.png"\; state="\{\{state\}\}">z</figure-callout>}}_0}^2+x^2+y^2}}\left]\right],{\mathrm{ub}}^{\&prime;}(x,y)=\mathrm{ub}(x,y)\&CenterDot;G(x,y)$

$\mathrm{uc}(x,y)=F^{-1}\left[F\right[{\mathrm{ub}}^{\&prime;}(x,y)]\&CenterDot;F[\frac{{\mathrm{ie}}^{-\mathrm{ik}\sqrt{{z_1}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}}{\mathrm{\&lambda;}\sqrt{{z_1}^2+x^2+y^2}}\left]\right],{\mathrm{uc}}^{\&prime;}(x,y)=\mathrm{uc}(x,y)\&CenterDot;L(x,y)$

$\mathrm{ud}(x,y)=F^{-1}\left[F\right[{\mathrm{uc}}^{\&prime;}(x,y)]\&CenterDot;F[\frac{{\mathrm{ie}}^{-\mathrm{<figure-callout\; id="2"\; label="ik\; z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{{z_{}}^{}}\sqrt{{{}_2}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}}{\mathrm{\&lambda;}\sqrt{{{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}}_2}^2+x^2+y^2}}\left]\right],I(x,y)={\left|\mathrm{ud}(x,y)\right|}^2...\left(18\right)$

If (x, simulation y) then can obtain the such result of Figure 34 to carry out the intensity distributions I of the sensitive surface 36a of light accepting part 36.Will (x, result y) represents in Figure 34 according to formula (18) calculating strength distribution I.

Then, to using 4 method for detecting position of cutting apart PD55 to describe.

As can be known with corresponding with respect to the displacement of the directions X of transparent body angle grid 30, Y direction, light 42 ₁～42 ₉The spot intensity height change of crest on directions X, Y direction only respectively.Utilize this principle, can use shown in Figure 35 4 to cut apart PD55 and detect these displacements.Illustrate that below it detects principle and analog result.

4 cut apart PD55 as mentioned above, 4 photo detector 55a～55d are made up each two row form on X, Y direction, identical in fact with the situation that 4 photodiodes are set.

In Figure 35, be output as S if establish the sensor of directions X, Y direction _X, S _Y, then utilize I shown in Figure 35 ₁～I ₄, define the output of photo detector 55a～55d respectively as described below.

[formula 18]

$S_X=100\&CenterDot;\frac{I_3+I_4-I_1-I_2}{I_1+I_2+I_3+I_4}(\%)...\left(19\right)$

$S_Y=100\&CenterDot;\frac{I_2+I_3-I_1-I_4}{I_1+I_2+I_3+I_4}(\%)...\left(20\right)$

And then, as shown in figure 36,, can obtain the rotation angle of θ z direction according to the relative position relation of X, Y displacement by using two detectors.

Here, the detection method to the posture that uses multicomponent type PD describes.

The detection method of cutting apart PD55 with use above-mentioned 4 is different, detects the action one by one of the crest of hot spot by using multicomponent type PD, can detect the more freedom degree.On the sensitive surface 36a of light accepting part 36 (with reference to Figure 32), on the XY direction, a plurality of crests are arranged with certain periodic arrangement.Among this has a plurality of crests, for 9 crest configurations photodiode 51～54,56～59 as shown in Figure 37 at center.This light accepting part 36 disposes the photodiode 52,54,56,58 of 1 element on 4 limits of sensitive surface 36a, configuration is cut apart PD51,53,57,59 with 2 of the oblique incision of square on four jiaos of sensitive surface 36a.The method that the light accepting part 36 that is made of this multicomponent type PD for use comes the 3DOF of detection position, posture, next coming in order describe the detection method of XY position, the detection method of θ z.

At first, the detection method to the XY position describes.

Figure 38 (A)～(E) is as an example and expression detects the method for displacement of directions X of the transmission-type pick-up unit of Figure 28.If produce displacement on directions X, then shown in Figure 38 (A)～(E), on photodiode 51～54,56～59, height profile only takes place about directions X the crest of hot spot changes.If the sensor of the directions X of light accepting part 36 is output as S _XUtilization is configured in the intensity detection value I of the photodiode 54,56 on the centre position on directions X both sides of sensitive surface 36a _X1, I _X2, the sensor output S of light accepting part 36 is obtained in the calculating of through type (21) _X

The sensor of establishing the Y direction of light accepting part 36 on the Y direction too is output as S _YUtilization is configured in the intensity detection value I of the photodiode 52,58 on the centre position on Y direction both sides of sensitive surface 36a _Y1, I _Y2, the sensor output S of the directions X of light accepting part 36 is obtained in the calculating of through type (22) _Y

[formula 19]

$S_X=100\&CenterDot;\frac{I_{X2}-I_{X1}}{I_{X1}+{\mathrm{<figure-callout\; id="2"\; label="I\; X"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">I</figure-callout>}}_X}...(\%)...\left(21\right)$

$S_Y=100\&CenterDot;\frac{I_{Y2}-I_{Y1}}{I_{Y1}+I_{Y2}}(\%)...\left(22\right)$

Then, the detection method of the θ z direction of opposing connection Z axle describes.

If rotation has taken place θ z, then light 42 ₁～42 ₉Whole hot spots serve as that axle only rotates identical θ z with the crest of spot center.Here, be configured in by use that 2 on four jiaos of sensitive surface 36a are cut apart PD51,53,57,8 photo detectors of 59 detect spot intensities and change, can detect θ z.The detection principle of the detection method of the XY position of the transmission-type pick-up unit of expression Figure 28 among Figure 39 (A)～(C).If establish 2 cut apart PD51,53,57,59 8 photo detector 51a, 51b, 53a, 53b, 57a, 57b, 59a, 59b are output as I _{θ z1}, I _{θ z2}, I _{θ z3}, I _{θ z4}, I _{θ z5}, I _{θ z6}, I _{θ z7}, I _{θ z8}, the output S of the θ z direction of light accepting part 36 then _{θ z}Obtain by following formula (23).

[formula 20]

$S_{\mathrm{\&theta;Z}}=100\&CenterDot;\frac{(I_{\mathrm{\&theta;<figure-callout\; id="2"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}2}+I_{\mathrm{\&theta;<figure-callout\; id="4"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}4}+I_{\mathrm{\&theta;z}6}+I_{\mathrm{\&theta;z}8})-(I_{\mathrm{\&theta;z}1}+I_{\mathrm{\&theta;z}3}+I_{\mathrm{\&theta;z}5}+I_{\mathrm{\&theta;z}7})}{(I_{\mathrm{\&theta;z}1}+I_{\mathrm{\&theta;z}3}+I_{\mathrm{\&theta;z}5}+I_{\mathrm{\&theta;z}7})+(I_{\mathrm{\&theta;<figure-callout\; id="2"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}2}+I_{\mathrm{\&theta;<figure-callout\; id="4"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}4}+I_{\mathrm{\&theta;z}6}+I_{\mathrm{\&theta;z}8})}(\%)...\left(23\right)$

Figure 40 represents the variation of optical system of the transmission-type pick-up unit of present embodiment.

As shown in figure 40, the benchmark grid in the transmission-type pick-up unit 22 also can be that the back side with a pair of transparent body angle grid 30 leans against the surface that is fitted in transparency carrier 32 privately and the structure on the back side each other.That is, this benchmark grid possess transparency carrier 32, be provided in transparency carrier 32 lip-deep the 1st benchmark grid 30 and with on the back side that is provided in transparency carrier 32 with the 1st benchmark grid 30 be 180 the degree towards the 2nd benchmark grid 30.By this benchmark grid is used in the optical system of transmission-type pick-up unit 22, and can access the position of directions X except the Z direction and Y direction and around rotation angle θ x, the θ y of each, the detection signal of θ z.

Then, with reference to the structure of Figure 41 explanation as the reflection-type pick-up unit 70 of reflection-type surface encoder.

As shown in figure 41, reflection-type pick-up unit 70 possesses: transparent body angle grid (benchmark grid) 30 extends to form on the 1st 14 moving direction; Substrate 74 is formed with reflecting surface (catoptron) 74a that transparent body angle grid 30 is remained plumbness; Optical sensor unit 76 sends the multi beam directional light towards transparent body angle grid 30, and the reflected light from reflecting surface 74a is subjected to light.Optical sensor unit 76 has illuminating part (not shown) that sends the multi beam directional light and the light accepting part (not shown) that transmission transparent body angle grid 30 is subjected to light by the multi beam reflected light of reflecting surface 74a reflection.

In reflection-type pick-up unit 70, owing to be the structure that is provided with optical sensor unit 76 at detection faces 30a opposite side with transparent body angle grid 30, can make transparent body angle grid 30 approach linear motor 18 so compare, can detect directions X, Y direction apart from linear motor 18 nearer positions in this section and around each angle θ x, θ y, θ z with the transmission-type pick-up unit of above-mentioned Figure 28.

Here, the principle to the state-detection of reflection-type pick-up unit 70 describes.

Expression is attached to the model of the transparent body angle grid 30 on the reflecting surface 74a among Figure 42.The shape of the detection faces 30a of transparent body angle grid 30 is identical with the transmission-type pick-up unit of above-mentioned Figure 28, as the formula (24), is formed by stacking with making sinusoidal wave 2 dimensions.

[formula 21]

$h(x,y)=-A_x\cos \left[2\mathrm{\&pi;}\frac{x}{P_x}\right]-A_y\cos \left[2\mathrm{\&pi;}\frac{y}{P_y}\right]...\left(24\right)$

Here, the spacing P of the surface configuration of transparent body angle grid 30 _x, P _yBe the following magnitudes of 100 μ m, and amplitude A _x, A _yBe the following magnitude of 100nm, if to its incident light then bring into play the such effect of diffraction lattice.So the transmission-type pick-up unit with above-mentioned Figure 28 is identical here, when setting up the model of reflection-type pick-up unit 70, light is handled as ripple, resolve by calculating amplitude, phase place.That is, used herein is not the model of geometrical optics, but the model of wave optics.

In addition, in the following description, as shown in figure 42, suppose light from the vertical direction of transparent body angle grid 30 incide the position (x, y).At this moment, if advance to the reflecting surface 74a of substrate 74 from the face ∑, then light forward travel distance only be 2A-h (x, y) after, incide in the transparent body angle grid 30, only forward travel distance h (x, y).And, once more along identical light path, advance to the face ∑ by the light of reflecting surface 74a reflection.

In addition, the be reflected imaginary model of face 74a reflex time former state transmission of expression light among Figure 43.At this moment, be 1 if establishing the refractive index of transparent body angle grid 30 is n, establish the outer refractive indexes of transparent body angle grid 30, then the optical path length L of this light from the incident of face ∑, when advancing to face ∑ (be ∑ ') once more among Figure 43 represents like that suc as formula (25).

[formula 22]

L＝2{2A-h(x，y)}+n·2h(x，y) ……(25)

Because optical path length only has L when the face ∑ advances to the face ∑ once more, thus phase delay it be multiply by wave number k (=2 π/λ, λ: the kL light wavelength).Thus, the phase function Gr that transparent body angle grid 30 is had (x, y) represent like that by formula described as follows (26).

[formula 23]

Gr(x，y)＝e ^-ikL

＝e ^{-ik2{2A-h(x，y)+n·h(x，y)}} ……(26)

＝ ^{e-ik2(n-1)h(x，y)}·e ^-i4kA

Because constant term e ^-i4kACan ignore, so (x y) can be suc as formula (27) expression like this for Gr.

Gr(x，y)＝e ^{-i2k(n-1)h(x，y)} ……(27)

During when the displacement that in transparent body angle grid 30, produces directions X, Y direction with around the rotation of Z axle, formula (27) can be showed as following formula (28).

[formula 24]

$\mathrm{Gr}(x,y)=e^{-i2k(n-1)\{h(x^{\&prime;}+\mathrm{\&Delta;x},y^{\&prime;}+\mathrm{\&Delta;y}){\mathrm{\&theta;}}_Y\&CenterDot;x+{\mathrm{\&theta;}}_x\&CenterDot;y\}}$

$\left[\begin{array}{c}{x}^{\&prime;}\\ y^{\&prime;}\end{array}\right]=\left[\begin{array}{cc}\cos {\mathrm{\&theta;}}_z& -\sin {\mathrm{\&theta;}}_z\\ \sin {\mathrm{\&theta;}}_z& \cos {\mathrm{\&theta;}}_z\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]...\left(28\right)$

It more than is the model that is attached to the transparent body angle grid 30 on the reflecting surface 74a.

Figure 44 represents the structure of optical system of the reflection-type pick-up unit 70 of Figure 41.In addition, in Figure 44, give identical label to the part identical with the transmission-type pick-up unit of above-mentioned Figure 28.

Optical sensor unit 76 is owing to be the structure with illuminating part 34 and light accepting part 36, thus with illuminating part 34 is compared with the structure that light accepting part 36 splits ground is provided with, can make the device integral miniaturization.The directional light 40 that penetrates from lasing light emitter (LD) 34a of illuminating part 34 incide with some cycles 2 dimensions be arranged with on the beam-splitter 38 of minute opening.

On beam-splitter 38, interfere transmission beam-deflection separation vessel (PBS) 78 and 1/4 wavelength plate 80 mutually by the light of each minute opening 38A～38I diffraction of comb mesh pattern.And, on transparent body angle grid 30, generate 9 directional lights 42 that crest is erect with opening interval identical distance with comb mesh pattern ₁～42 ₉

And then, transmission transparent body angle grid 30 and by reflecting surface 74a reflection, once more behind the transmission transparent body angle grid 30, by the directions reflection of beam-deflection separation vessel 78 to 90 degree, by object lens 44 optically focused to the sensitive surface 36a of light accepting part 36.

Same with the method that illustrates in the transmission-type pick-up unit of above-mentioned Figure 28, gather the model of reflection-type pick-up unit 70, obtain intensity distributions I on the sensitive surface 36a of light accepting part 36 (x, y).(x y) is represented by following formula (29) the intensity distributions I of the sensitive surface 36a of this embodiment.

[formula 25]

ua′(x，y)＝ua(x，y)·g(x，y)

$\mathrm{ub}(x,y)=F^{-1}\left[F\right[{\mathrm{ua}}^{\&prime;}(x,y)]\&CenterDot;F[\frac{{\mathrm{ie}}^{-\mathrm{<figure-callout\; id="0"\; label="ik\; z"\; filenames="A20058002142100631.png,A20058002142100632.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{{z_{}}^{}}\sqrt{{{}_0}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}}{\mathrm{\&lambda;}\sqrt{{{\mathrm{<figure-callout\; id="0"\; label="z"\; filenames="A20058002142100631.png,A20058002142100632.png"\; state="\{\{state\}\}">z</figure-callout>}}_0}^2+x^2+y^2}}\left]\right],{\mathrm{ub}}^{\&prime;}(x,y)=\mathrm{ub}(x,y)\&CenterDot;\mathrm{Gr}(x,y)$

$\mathrm{uc}(x,y)=F^{-1}\left[F\right[{\mathrm{ub}}^{\&prime;}(x,y)]\&CenterDot;F[\frac{{\mathrm{ie}}^{-\mathrm{ik}\sqrt{{z_1}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}}{\mathrm{\&lambda;}\sqrt{{z_1}^2+x^2+y^2}}\left]\right],{\mathrm{uc}}^{\&prime;}(x,y)=\mathrm{uc}(x,y)\&CenterDot;L(x,y)$

$\mathrm{ud}(x,y)=F^{-1}\left[F\right[{\mathrm{uc}}^{\&prime;}(x,y)]\&CenterDot;F[\frac{{\mathrm{ie}}^{-\mathrm{<figure-callout\; id="2"\; label="ik\; z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{{z_{}}^{}}\sqrt{{{}_2}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}}{\mathrm{\&lambda;}\sqrt{{{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}}_2}^2+x^2+y^2}}\left]\right],I(x,y)={\left|\mathrm{ud}(x,y)\right|}^2...\left(29\right)$

Then, with reference to Figure 45 the structure of the reflection-type pick-up unit 90 of use reflecting surface angle grid is described.

As shown in figure 45, reflection-type pick-up unit 90 possesses: reflecting surface angle grid (benchmark grid) 92 extends to form on the 1st 14 moving direction; Substrate 94 is used for reflecting surface angle grid 92 is remained plumbness; Optical sensor unit 76, orientating reflex face angle grid 92 sends the multi beam directional light, and reflected light is subjected to light.Reflecting surface angle grid 92 is formed with catoptrical reflectance coating on the surface of detection faces 92a.Optical sensor unit 76 has illuminating part (not shown) that sends the multi beam directional light and the light accepting part (not shown) that the multi beam reflected light that the detection faces 92a by reflecting surface angle grid 92 reflects is subjected to light.

In reflection-type pick-up unit 90, owing to be the structure that optical sensor unit 76 is set at the detection faces 92a opposite side with reflecting surface angle grid 92, can make reflecting surface angle grid 92 approach linear motor 18 so compare, can detect directions X, Y direction apart from linear motor 18 nearer positions in this section and around each angle θ x, θ y, θ z with the transmission-type pick-up unit of above-mentioned Figure 28.

Here, the principle to the state-detection of reflection-type pick-up unit 90 describes.

Figure 46 represents the model of reflecting surface angle grid 92.The shape of reflecting surface angle grid 92 and the transmission-type pick-up unit of above-mentioned Figure 28 are same, as the formula (30), are formed by stacking with making sinusoidal wave 2 dimensions.

[formula 26]

$h(x,y)=-A_x\cos \left(2\mathrm{\&pi;}\frac{x}{P_x}\right)-A_y\cos \left(2\mathrm{\&pi;}\frac{y}{P_y}\right)...\left(30\right)$

Here, the spacing P of the surface configuration of reflecting surface angle grid 92 _x, P _yBe the following magnitudes of 100 μ m, and amplitude A _x, A _yBe the following magnitude of 100nm, if to its incident light then play the such effect of diffraction lattice.So, when setting up the model of scrambler, light is handled as ripple here, resolve by calculating amplitude, phase place.That is, used herein is not the model of geometrical optics, but the model of wave optics.

As shown in figure 46, suppose light vertically incide from the top of reflecting surface angle grid 92 position (x, y).At this moment, light from the face ∑ advanced apart from 2A-h (x, y) after, be formed on the reflectance coating reflection on the detection faces 82 of reflecting surface angle grid 92.In addition, the optical path length L of light from the incident of face ∑, when advancing to face ∑ (be ∑ ') once more among Fig. 2 represents like that suc as formula (31).

[formula 27]

L＝2{2A-h(x，y)} ……(31)

Because optical path length only has L when the face ∑ advances to the face ∑ once more, thus phase delay it be multiply by wave number k (=2 π/λ, λ: the kL light wavelength).Thus, the phase function Gr that reflecting surface angle grid 92 is had (x, y) represent like that by formula described as follows (32).

[formula 28]

Gr(x，y)＝e ^-ikL

＝e ^{-ik2{2A-h(x，y)}}

＝e ^-ik2h(x，y)·e ^-i4kA ……(32)

Because constant term e ^-i4kACan ignore, so (x y) can be suc as formula (33) expression like this for Gr.

Gr(x，y)＝e ^-i2kh(x，y) ……(33)

During when the displacement that in reflecting surface angle grid 92, produces directions X, Y direction with around the rotation of Z axle, formula (33) can be showed as following formula (34).

[formula 29]

$\mathrm{Gr}(x,y)=e^{-i2k\{h(x^{\&prime;}+\mathrm{\&Delta;x},y^{\&prime;}+\mathrm{\&Delta;y})+{\mathrm{\&theta;}}_Y\&CenterDot;x+{\mathrm{\&theta;}}_Y\&CenterDot;y\}}$

$\left[\begin{array}{c}{x}^{\&prime;}\\ y^{\&prime;}\end{array}\right]=\left[\begin{array}{cc}\cos {\mathrm{\&theta;}}_z& -\sin {\mathrm{\&theta;}}_z\\ \sin {\mathrm{\&theta;}}_z& \cos {\mathrm{\&theta;}}_z\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]...\left(34\right)$

More than the model of reflecting surface angle grid 92 is illustrated.

Figure 47 represents the structure of optical system of the reflection-type pick-up unit (reflection-type surface encoder) of Figure 45.In addition, in Figure 47, give identical label to the part identical with the reflection-type pick-up unit of above-mentioned Figure 41.

As shown in figure 47, optical sensor unit 76 is owing to be the structure with illuminating part 34 and light accepting part 36, thus with illuminating part 34 is compared with the structure that light accepting part 36 splits ground is provided with, can make the device integral miniaturization.The directional light 40 that penetrates from lasing light emitter (LD) 34a of illuminating part 34 incide with some cycles 2 dimensions be arranged with on the beam-splitter 38 of minute opening.

On beam-splitter 38, interfere mutually by the light of each minute opening 38A～38I diffraction of comb mesh pattern, and transmission beam-deflection separation vessel (PBS) 78 and 1/4 wavelength plate 80.And, on transparent body angle grid 30, generate 9 directional lights 42 that crest is erect with opening interval identical distance with comb mesh pattern ₁～42 ₉

And then, the reflectance coating of the detection faces 92a of the face angle that is reflected grid 92 reflection, by the directions reflection of beam-deflection separation vessel 78 to 90 degree, by object lens 44 optically focused to the sensitive surface 36a of light accepting part 36.

Identical with the method described in the transmission-type pick-up unit of above-mentioned Figure 28, gather the model of reflection-type pick-up unit 90, obtain the sensitive surface 36a of light accepting part 36 intensity distributions I (x, y).(x y) is represented by following formula (35) the intensity distributions I of the sensitive surface 36a of this embodiment.

[formula 30]

ua′(x，y)＝ua(x，y)·g(x，y)

$\mathrm{ub}(x,y)=F^{-1}\left[F\right[{\mathrm{ua}}^{\&prime;}(x,y)]\&CenterDot;F[\frac{{\mathrm{ie}}^{-\mathrm{<figure-callout\; id="0"\; label="ik\; z"\; filenames="A20058002142100631.png,A20058002142100632.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{{z_{}}^{}}\sqrt{{{}_0}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}}{\mathrm{\&lambda;}\sqrt{{{\mathrm{<figure-callout\; id="0"\; label="z"\; filenames="A20058002142100631.png,A20058002142100632.png"\; state="\{\{state\}\}">z</figure-callout>}}_0}^2+x^2+y^2}}\left]\right],{\mathrm{ub}}^{\&prime;}(x,y)=\mathrm{ub}(x,y)\&CenterDot;\mathrm{Gr}(x,y)$

$\mathrm{uc}(x,y)=F^{-1}\left[F\right[{\mathrm{ub}}^{\&prime;}(x,y)]\&CenterDot;F[\frac{{\mathrm{ie}}^{-\mathrm{ik}\sqrt{{z_1}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}}{\mathrm{\&lambda;}\sqrt{{z_1}^2+x^2+y^2}}\left]\right],{\mathrm{uc}}^{\&prime;}(x,y)=\mathrm{uc}(x,y)\&CenterDot;L(x,y)$

$\mathrm{ud}(x,y)=F^{-1}\left[F\right[{\mathrm{uc}}^{\&prime;}(x,y)]\&CenterDot;F[\frac{{\mathrm{ie}}^{-\mathrm{<figure-callout\; id="2"\; label="ik\; z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">ik</figure-callout>}\sqrt{{z_{}}^{}}\sqrt{{{}_2}^2+x^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}}}{\mathrm{\&lambda;}\sqrt{{{\mathrm{<figure-callout\; id="2"\; label="z"\; filenames="A20058002142100771.png,A20058002142100911.png"\; state="\{\{state\}\}">z</figure-callout>}}_2}^2+x^2+y^2}}\left]\right],I(x,y)={\left|\mathrm{ud}(x,y)\right|}^2...\left(35\right)$

Figure 48 is the figure that is illustrated in the structure of the optical sensor unit 100 that uses in the reflection-type pick-up unit of one embodiment of the present invention.In addition, in Figure 48, give identical label and omit explanation for the part identical with the optical sensor unit 76 of above-mentioned Figure 44.

As shown in figure 48, optical sensor unit 100 has illuminating part 34 and light accepting part 36, and the directional light 40 that penetrates from LASER Light Source (LD) 34a of illuminating part 34 incides on the plane of incidence 102a that plays as the transparent body angle grid 102 of the function of spectrophotometric device.

The plane of incidence 102a of transparent body angle grid 102 constitutes the same shape of detection faces 30a with above-mentioned transparent body angle grid 30.That is, on plane of incidence 102a, on 2 dimension directions, alternately form the concave curved surface and the convex surface of the solid of the profile that has the predetermined sinusoidal wave from the teeth outwards.The concaveconvex shape of this plane of incidence 102a by with the same method of above-mentioned transparent body angle grid 30 evenly and form tiny concave curved surface, convex surface accurately.

Illuminating part 34 is set to, and is opposed from vertical direction with respect to the plane of incidence 102a of transparent body angle grid 102.The directional light 40 that penetrates from illuminating part 34 is owing to be radiated on the plane of incidence 102a, so concave curved surface by plane of incidence 102a and convex surface play the function as tiny lens, by beam split for by the light of concave curved surface diffusion and the multi-beam that overlaps by the light that convex surface gathers.Can being set selectively by the radius-of-curvature of concave curved surface and convex surface of this moment by the quantity of the light of beam split and spacing.

Thereby, replace above-mentioned beam-splitter 38 as spectrophotometric device by using transparent body angle grid 102, can carry out the beam split more accurate than beam-splitter 38.

By transmittance beam-deflection separation vessel (PBS) 78 after 102 beam split of transparent body angle grid and 1/4 wavelength plate 80.And, on transparent body angle grid 30, generate the directional light 42 that crest is erect with predetermined interval ₁～42 _n

And then, transmission transparent body angle grid 30 and by reflecting surface 74a reflection, once more behind the transmission transparent body angle grid 30, by the directions reflection of beam-deflection separation vessel 78 to 90 degree, by object lens 44 optically focused to the sensitive surface 36a of light accepting part 36.

In addition, by in the photo detector of light accepting part 36, adopting multicomponent type PD (with reference to Figure 32) and CCD element, except the XY position, the inclination attitude of can also instrumentation bringing because of the rotation around each of inclination, rotation, deflection etc.

Below clear in detail preferred embodiment of the present invention, but the present invention is not limited to these embodiments, can carry out various distortion, change in the scope of the purport of the present invention that claims are put down in writing.

Industrial applicibility

The benchmark grid that the present invention can be applied in the shape that can use easy manufacturing easily Carry out the detection of state of 5 frees degree of platform and the detection that can improve the precision of detection Device and table apparatus.

In the above-described embodiment, say as an example of the checkout gear of the position of monitor station an example Bright, but be not limited to this, certainly can detect the shift position of other movable bodys and be accompanied by and move Moving state (inclination).

In addition, as checkout gear, for example except linear encoder, also can use rotation Encoder, and then, as the device beyond the table apparatus, also can be applied in hard disk unit and reach In the DVD device.

In addition, also can be applied in input unit and the computer game dress of the PC of mouse etc. In the input unit of putting.

And then, owing to also can be applied in the object information (position of goods for example of logistics relation Put information) and the checkout gear of 2 dimension bar-codes of commodity in, so also can be applied to and IC In the equal highdensity optical label of label.

Claims (19)

1, a kind of pick-up unit is characterized in that, possesses:

The benchmark grid has the shape that periodically changes on 2 dimension directions;

Light source is to said reference grid irradiates light;

Spectrophotometric device has a plurality of peristomes, will be multi-beam from the light beam split of above-mentioned light source irradiation by above-mentioned a plurality of peristomes;

Testing agency has the photo detector that the multi beam reflected light by the reflection of said reference grid is subjected to simultaneously light;

And above-mentioned testing agency is subjected to the catoptrical variation of above-mentioned multi beam of light according to above-mentioned photo detector, detects the state of relative said reference grid.

2, pick-up unit as claimed in claim 1 is characterized in that,

Above-mentioned photo detector is made of a plurality of photodiodes;

In the central authorities of the face of the above-mentioned testing agency that above-mentioned multi beam reflected light is subjected to light, have at least and carry out with the X-axis being the status detection that moves of the rotation of turning axle and being 4 photodiodes of the status detection that moves of the rotation of turning axle with the Y-axis.

3, pick-up unit as claimed in claim 1 is characterized in that, has at least at the face of above-mentioned testing agency four jiaos that to be used for carrying out with the Z axle be that two of the status detection that moves of the rotation of turning axle are one group photodiode.

4, pick-up unit as claimed in claim 1 is characterized in that, uses charge-coupled device (CCD) in above-mentioned photo detector.

5, pick-up unit as claimed in claim 1 is characterized in that, the said reference grid constitutes bisymmetric shape in the face with respect to the said reference grid.

6, a kind of pick-up unit is characterized in that, possesses:

The benchmark grid has from the teeth outwards in 2 dimensions and alternately forms the concave curved surface with predetermined shape and the detection faces of convex surface on the directions;

Illuminating part is provided with movably with respect to the said reference grid, shines the multi beam directional light from the vertical direction of said reference grid towards above-mentioned detection faces;

Light accepting part is set to move integratedly with above-mentioned illuminating part, has a plurality of photo detectors that the above-mentioned multi beam directional light of transmission said reference grid are subjected to light.

7, a kind of pick-up unit is characterized in that, possesses:

The benchmark grid has from the teeth outwards in 2 dimensions and alternately forms the concave curved surface with predetermined shape and the detection faces of convex surface on the directions;

Reflecting surface is formed on the back side of said reference grid;

Illuminating part is provided with movably with respect to the said reference grid, shines the multi beam directional light from the vertical direction of said reference grid towards above-mentioned detection faces;

Light accepting part is set to move integratedly with above-mentioned illuminating part, has a plurality of photo detectors that the multi beam directional light from above-mentioned reflecting surface reflection are subjected to light.

8, a kind of pick-up unit is characterized in that, possesses:

The benchmark grid has from the teeth outwards in 2 dimensions and alternately forms the concave curved surface with predetermined shape and the detection faces of convex surface on the directions;

Reflecting surface is formed on the above-mentioned detection faces;

Illuminating part is provided with movably with respect to the said reference grid, shines the multi beam directional light from the vertical direction of said reference grid towards above-mentioned detection faces;

Light accepting part is set to move integratedly with above-mentioned illuminating part, has a plurality of photo detectors that the multi beam directional light from above-mentioned reflecting surface reflection are subjected to light.

9, pick-up unit as claimed in claim 6 is characterized in that, above-mentioned illuminating part has light source and will be the spectrophotometric device of multi beam directional light from the light beam split of above-mentioned light source.

10, pick-up unit as claimed in claim 9 is characterized in that, above-mentioned spectrophotometric device has in 2 dimensions and alternately forms the concave curved surface with predetermined shape and the plane of incidence of convex surface on the directions.

11, pick-up unit as claimed in claim 6 is characterized in that, above-mentioned light accepting part has the photo detector of the number of Duoing than above-mentioned multi beam directional light, sets 1 photo detector at least corresponding to 1 bundle directional light.

12, pick-up unit as claimed in claim 6, it is characterized in that, possesses arithmetical organ, this arithmetical organ is transfused to the corresponding detection signal of light intensity with the above-mentioned multi beam directional light that is subjected to light by above-mentioned photo detector, according to the rate of travel of the above-mentioned illuminating part of the change calculations of each light intensity distributions with respect to the said reference grid.

13, pick-up unit as claimed in claim 12, it is characterized in that, above-mentioned arithmetical organ calculates above-mentioned illuminating part and the light accepting part relative tilt angle with respect to above-mentioned detection faces according to the variation of the light intensity distributions of the above-mentioned multi beam directional light that is subjected to light by above-mentioned a plurality of photo detectors.

14, pick-up unit as claimed in claim 6, it is characterized in that, the said reference grid possesses transparency carrier, is provided in lip-deep the 1st benchmark grid of above-mentioned transparency carrier and makes it and above-mentioned the 1st benchmark grid constitute 180 degree towards mode be provided in the 2nd benchmark grid at the back side of above-mentioned transparency carrier.

15, a kind of table apparatus, drives above-mentioned motor, makes above-mentioned float-up device that floats with respect to pedestal and detect above-mentioned status detection device the platform that possesses pedestal, moves on said base, it is characterized in that,

Above-mentioned detection device possesses:

The benchmark grid has the shape that periodically changes on 2 dimension directions;

Light source is towards said reference grid irradiates light;

Spectrophotometric device has a plurality of peristomes, will be multi-beam from the light beam split of above-mentioned light source irradiation by above-mentioned a plurality of peristomes;

Testing agency has the photo detector that the multi beam reflected light by the reflection of said reference grid is subjected to simultaneously light;

And above-mentioned detecting element is subjected to the catoptrical variation of above-mentioned multi beam of light according to above-mentioned photo detector, detects the state of relative said reference grid.

16, table apparatus as claimed in claim 15 is characterized in that, uses planar motors in said motor, uses air bearing in above-mentioned float-up device.

17, a kind of table apparatus, the platform that possesses pedestal, sets movably with respect to said base, to above-mentioned the driving mechanism of giving driving force, detect above-mentioned the pick-up unit that moves and control above-mentioned driving mechanism so that above-mentioned control gear that moves at a predetermined velocity according to the testing result of above-mentioned detection device, it is characterized in that

Above-mentioned detection device possesses:

The benchmark grid has from the teeth outwards in 2 dimensions and alternately forms the concave curved surface with predetermined shape and the detection faces of convex surface on the directions;

Illuminating part is provided with movably with respect to the said reference grid, sends the multi beam directional light from the vertical direction of said reference grid towards above-mentioned detection faces;

Light accepting part is set to move integratedly with above-mentioned illuminating part, has a plurality of photo detectors that the above-mentioned multi beam directional light of transmission said reference grid are subjected to light.

18, table apparatus as claimed in claim 17 is characterized in that, above-mentioned driving mechanism is a pair of linear motor, and above-mentioned control gear is gone forward side by side and driven above-mentioned a pair of linear motor.

19, table apparatus as claimed in claim 18 is characterized in that, with above-mentioned detection device be provided in above-mentioned linear motor near.

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