Stage apparatus, image projector apparatus having stage apparatus, and imaging apparatus having stage apparatus

Patent metadata

Field	Value
Publication number	US-10084963-B2
Application number	US-201615362059-A
Country	US
Kind code	B2
Filing date	Nov 28, 2016
Priority date	Nov 30, 2015
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

A stage apparatus includes a base member, a movable member which moves relative to the base member, thrust generators which generate thrust forces against the movable member, and a position detector which detects a translation position and a rotational position of the movable member relative to the base member. An interaction of the thrust forces causes the movable member to at least one of: translate, rotate, translate while rotating, and translate after rotating relative to the base member. The position detector includes permanent magnets fixed to one of the movable member and the base member, and pairs of magnetic sensors fixed to the other of the movable member and the base member. The position detector detects the translation position and the rotational position of the movable member relative to the base member based on detection signals input from the pairs of magnetic sensors.

First claim

What is claimed is:

1. A stage apparatus comprising:
a base;
a movable stage configured to move relative to said base;
a plurality of magnetic first thrust generation circuits configured to generate thrust forces in a first direction against said movable stage; and
a position detector comprising permanent magnets fixed to one of said movable stage and said base, and further comprises pairs of magnetic sensors including at least one pair of first-direction magnetic sensors configured to detect a magnetic force of a first-direction permanent magnet of said permanent magnets, said pairs of magnetic sensors fixed to the other of said movable stage and said base while being spaced from each other with a predetermined distance therebetween in said first direction, the position detector configured to detect a translation position and a rotational position of said movable stage relative to said base,
wherein an interaction of said thrust forces in said first direction causes said movable stage to at least one of:
translate relative to said base in said first direction,
rotate relative to said base about a direction different from said first direction,
translate relative to said base in said first direction while rotating relative to said base about the direction different from said first direction, and
translate relative to said base in said first direction after rotating relative to said base about the direction different from said first direction,

and
wherein said position detector is configured to detect said translation position of said movable stage relative to said base based on-a pair of detection signals input from said pair of first-direction magnetic sensors.

2. The stage apparatus according to claim 1 , further comprising a magnetic second thrust generation circuit and a magnetic third thrust generation circuit which generate thrust forces in a second direction and a third direction, respectively, that are mutually different and different from said first direction,
wherein an interaction of said thrust forces in said second direction and said third direction causes said movable stage to at least one of:
translate in said second direction,
translate in said third direction, and
rotate about said first direction,

wherein said permanent magnets includes a second-direction permanent magnet,
wherein said pairs of magnetic sensors include at least one pair of second-direction magnetic sensors which are fixed to said other of said movable stage and said base and spaced from each other with a predetermined distance therebetween in said second direction to detect magnetic force of said second-direction permanent magnet,
wherein said pairs of magnetic sensors include at least one pair of third-direction magnetic sensors which are fixed to said other of said movable stage and said base and spaced from each other with a predetermined distance therebetween in said third direction to detect magnetic force of said third-direction permanent magnet,
wherein said position detector detects a translation position of said movable stage in said second direction based on a pair of detection signals input from said pair of second-direction magnetic sensors, and
wherein said position detector detects a translation position of said movable stage in said third direction based on a pair of detection signals input from said pair of third-direction magnetic sensors.

3. The stage apparatus according to claim 2 , wherein at least one of said second thrust generation circuit and said third thrust generation circuit comprises at least two thrust generation circuits, and
wherein said movable stage can be rotated about said first direction by interaction of said thrust forces in one of said second direction and said third direction generated by said at least two thrust generation circuits.

4. The stage apparatus according to claim 3 , wherein a plurality of the position detectors that are each configured of said pair of second-direction magnetic sensors detect said rotational position of said movable stage about said first direction based on detection signals input from said pairs of second-direction magnetic sensors of said plurality of position detectors.

5. The stage apparatus according to claim 3 , wherein a plurality of the position detectors that are configured of said pair of third-direction magnetic sensors detect said rotational position of said movable stage about said first direction based on detection signals input from said pairs of third-direction magnetic sensors of said plurality of position detectors.

6. The stage apparatus according to claim 2 , wherein a driven component having a flat front surface and a low-profile shape is fixed to said movable stage,
wherein said first direction is orthogonal to said flat front surface, and
wherein said second direction and said third direction are orthogonal to each other, orthogonal to said first direction, and parallel to said flat front surface.

7. The stage apparatus according to claim 6 , wherein said base comprises a front fixed yoke and a rear fixed yoke which face said movable stage from front and rear thereof, respectively,
wherein said thrust generation circuits comprise a plurality of drive coils fixed to one of said movable stage and the front and rear fixed yokes, and a plurality of permanent magnets fixed to the other of said movable stage and the front and rear fixed yokes, and
wherein said pairs of magnetic sensors are positioned in air-core areas of said drive coils to detect magnetic force of said permanent magnets fixed to said other of said movable stage and the front and rear fixed yokes.

8. The stage apparatus according to claim 7 , wherein said first thrust generation circuits comprise drive coils and permanent magnets arranged at least three substantially equi-distant positions outside of said driven component in a radial direction from an axis extending through a center of said driven component in said first direction, and circumferentially arranged at equi-angular intervals about said axis.

9. The stage apparatus according to claim 8 , wherein said drive coils comprise circular and flat drive coils which are fixed to said movable stage, and
wherein each pair of said pairs of first-direction magnetic sensors are positioned in said air-core area of associated one of said circular and flat drive coils to be spaced from each other with a predetermined distance therebetween in said first direction.

10. The stage apparatus according to claim 8 , wherein said drive coils comprise circular and flat drive coils which are fixed to said front fixed yoke and said rear fixed yoke, and
wherein each pair of said pairs of first-direction magnetic sensors are positioned in said air-core areas of associated two of said circular and flat drive coils which are fixed to said front fixed yoke and said rear fixed yoke, respectively.

11. The stage apparatus according to claim 9 , wherein said permanent magnets are arranged on said front fixed yoke and said rear fixed yoke so that same magnetic poles of said permanent magnets are placed face-to-face.

12. The stage apparatus according to claim 8 , wherein said position detector detects a position of said movable stage in said first direction and a tilting position of said movable stage about one of said second direction and said third direction based on the quotient of the sum of a pair of detection signals of said pairs of first-direction magnetic sensors and the difference between said pair of detection signals.

13. The stage apparatus according to claim 7 , wherein said drive coils and said permanent magnets of each of said second thrust generation

Assignees

• Ricoh Imaging Co Ltd

Inventors

• Ito Eiichi

Classifications

• H04N23/687 Primary

  by shifting the lens or sensor position · CPC title

• G03B5/00 Primary

  Adjustment of optical system relative to image or object surface other than for focusing · CPC title

• H04N23/6812

  based on additional sensors, e.g. acceleration sensors · CPC title

• F16M11/18

  with mechanism for moving the apparatus relatively to the stand · CPC title

• F16M13/022

  repositionable · CPC title