Rim driven stepper motor and method of operation RIM driven

#This invention relates to rotational object support and control and more particularly to a linear stepper motor system for precisely controlling the rotating surface by applying rotational force at its periphery.

#All of the following patent applications are cross-referenced to one another, and all have been assigned to Texas Instruments Incorporated. These applications have been concurrently filed and are hereby incorporated in this patent application by reference:

#A System and Method for Support and Rotation of an Object, patent application Ser. No. 563,180; Linear Stepper Motor Design and Method of Operation, patent application Ser. No. 563,238; Apparatus and Method for Volume Graphics Display, patent application Ser. No. 563,372; Volume Display Development System, patent application Ser. No. 563,374; and Volume Display Optical System and Method, patent application Ser. No. 563,370.

#The foregoing objects, features and technical advantages, as well as others, of the invention will be more apparent from the following description of the drawings in which:

#FIG. 1 shows an illustration of a surface creating a defined volume within a dome;

#FIGS. 2-4 show graphically the volumes created by the rotating surface;

#Before beginning a discussion of the dome and linear stepper motor, a brief overview of the manner in which images are created in a defined volume is appropriate. Such a discussion is with respect to FIG. 9 where surface 12, which in one embodiment can be a single or double helix, defines a volume V as it rotates about some central point. Each point in time A, B and C shows the helix at the same physical (spatial) place but at a slightly different time. Since the helix is spinning at a rate of 600 rpm or faster, the human eye will treat the surface as being transparent. It is this transparency that allows for the creation of three-dimensional images when a coherent light source impacts the surface.

#Thus, coherent light source and optics system 10, discussed in more detail in concurrently filed patent application entitled "Volume Display Optical System and Method" provides a pulse of light 102 which has been spatially positioned and timed such that it impacts with surface 12 to form a point of light 105 at a height d1 from a base line 40. This pulse could be timed to arrive a little later in time and then it would impact surface 19 to create point of light 105' which is displaced from base line 40 at a height of d2. Still further delay in the beam 102 would result in a point of light 105" at a height of d3 from base line 40.

#Using this technique and understanding that light source 10 can deliver multiple light beams over a wide spatial range at each point in time, then three dimensional images can be formed from the points of light. Because the spinning helix is transparent to the human eye, the light spots will appear to be free floating and can be viewed from any angle and from any side.