What is claimed is:
1. An intervertebral spacer device, comprising:
a first baseplate, having an outwardly facing surface and an inwardly facing surface, the inwardly facing surface having a central post extending therefrom, the post having a longitudinal axis and a head end that is inwardly directed toward the second baseplate;
a second baseplate, having an outwardly facing surface and an inwardly facing surface, the second baseplate’s inwardly facing surface having a curvate pocket formed by a central portion of the second baseplate’s inwardly facing surface concaving outwardly to define a semispherical contour;
a convex structure having an outwardly facing surface and an inwardly facing surface, the convex structure further having a central bore extending from the convex structure’s inwardly facing surface to the convex structure’s outwardly facing surface, the convex structure’s central bore having an opening on the convex structure’s outwardly facing surface that is surrounded by a curvate taper defining a semispherical contour, the convex structure further having a protrusion adjacent the curvate taper; and
a ball defining a spherical contour, the ball having a curvate recess and a central bore; wherein
the ball is seatable in the curvate pocket; and wherein
the convex structure’s outwardly facing surface is securable to the second baseplate, the securing of the convex structure to the second baseplate establishing a curvate socket formed by the second baseplate’s curvate pocket and the convex structure’s curvate taper, the curvate socket defining a spherical contour, into which curvate socket the convex structure’s protrusion extends; and wherein
the ball is thereby capturable in the curvate socket, with the curvate socket’s spherical contour accommodating the ball’s spherical contour for rotation and angulation of the ball in the curvate socket about a central portion of the ball, and with the ball’s curvate recess accommodating the convex structure’s protrusion to limit rotation of the ball in the curvate socket; and wherein
the post is disposable through the convex structure’s central bore and the post’s head end is securable to the ball’s central bore, such that the post is accommodated for rotation in the convex structure’s central bore about the post’s longitudinal axis as the ball rotates in the curvate socket, and such that the post is accommodated for angulation in the convex structure’s central bore about the ball’s central portion as the ball angulates in the curvate socket; and wherein
the second baseplate includes a first part having the inwardly facing surface having the curvate pocket of the second baseplate, and a second part having the outwardly facing surface; and further comprising
a spring member disposed between the first part and the second part such that a compressive load applied to the outwardly facing surfaces of the baseplates is borne by the spring member.
2. The intervertebral spacer device of claim 1, wherein the ball’s curvate recess has boundaries that define limits of rotation of the ball within the curvate socket in that the ball’s rotation within the curvate socket is limited by interference between the convex structure’s protrusion and the boundaries.
3. The intervertebral spacer device of claim 2, wherein the ball’s curvate recess’s boundaries accommodate angulation of the ball within the curvate socket.
4. The intervertebral spacer device of claim 1, wherein each of the inwardly facing surface of the first baseplate and the inwardly facing surface of the convex structure has a respective perimeter region, and the perimeter regions have corresponding contours that reduce surface wearing during rotation and angulation of the ball in the curvate socket.
5. The intervertebral spacer device of claim 1, wherein the second part of the second baseplate travels toward the first part of the second baseplate as the spring member compresses under the compressive load.
6. The intervertebral spacer device of claim 1, wherein the spring member is ringshaped.
7. The intervertebral spacer device of claim 1, wherein the convex structure’s central bore is tapered to a larger diameter toward the convex structure’s inwardly facing surface, and the post is accommodated, by the convex structure’s central bore being tapered, for angulation in the convex structure’s central bore about the ball’s central portion as the ball angulates in the socket.
8. The intervertebral spacer device of claim 1, wherein at least one of the curvate pocket and the curvate taper has a hemispherical contour.
9. The intervertebral spacer device of claim 1, wherein at least one of the baseplates has a domed vertebral body contact surface on its outwardly facing surface.
10. The intervertebral spacer device of claim 1, wherein the post’s head end is compression lockable into the ball’s central bore.
11. The intervertebral spacer device of claim 1, wherein the convex structure’s protrusion has a radius of curvature, and the ball’s curvate recess has a semicylindrical contour having a depth accommodating, and a radius of curvature greater than, the protrusion’s radius of curvature.
12. An intervertebral spacer device, comprising:
a first baseplate, having an outwardly facing surface and an inwardly facing surface, the inwardly facing surface having a central post extending therefrom, the post having a longitudinal axis and a ball at a head end of the post that is inwardly directed toward the second baseplate, the ball defining a spherical contour and having a curvate recess;
a second baseplate, having an outwardly facing surface and an inwardly facing surface, the second baseplate having a convex structure establishing a curvate socket communicating with a central bore through the convex structure, the curvate socket defining a spherical contour, the convex structure further having a protrusion extending into the curvate socket; wherein
the ball is capturable in the curvate socket, with the curvate socket’s spherical contour accommodating the ball’s spherical contour for rotation and angulation of the ball in the curvate socket about a central portion of the ball;
with the ball’s curvate recess accommodating the convex structure’s protrusion to limit rotation of the ball in the curvate socket;
with the convex structure’s central bore accommodating the post for rotation in the convex structure’s central bore about the post’s longitudinal axis as the ball rotates in the curvate socket, and accommodating the post for angulation in the convex structure’s central bore about the ball’s central portion as the ball angulates in the curvate socket; and further comprising
a spring member housed by the second baseplate such that a compressive load applied to the outwardly facing surfaces of the baseplates is borne by the spring member.
13. The intervertebral spacer device of claim 12, wherein the ball’s curvate recess has boundaries that define limits of rotation of the ball within the curvate socket in that the ball’s rotation within the curvate socket is limited by interference between the convex structure’s protrusion and the boundaries.
14. The intervertebral spacer device of claim 13, wherein the ball’s curvate recess’s boundaries accommodate angulation of the ball within the curvate socket.
15. The intervertebral spacer device of claim 12, wherein each of the first baseplate and the convex structure has a respective inwardly facing perimeter region, and the perimeter regions have corresponding contours that reduce surface wearing during rotation and angulation of the ball in the curvate socket.
16. The intervertebral spacer device of claim 12, wherein the convex structure’s central bore is tapered to a larger diameter toward the first baseplate, and the post is accommodated, by the convex structure’s central bore being tapered, for angulation in the convex structure’s central bore about the ball’s central portion as the ball angulates in the curvate socket.
17. The intervertebral spacer device of claim 12, wherein at least one of the baseplates has a domed vertebral body contact surface on its outwardly facing surface.
18. The intervertebral spacer device of claim 12, wherein the convex structure’s protrusion has a radius of curvature, and the ball’s curvate recess has a semicylindrical contour having a depth accommodating, and a radius of curvature greater than, the protrusion’s radius of curvature.
19. An artificial intervertebral disc, comprising:
a first baseplate, having an outwardly facing surface and an inwardly facing surface having a central post extending therefrom, the post having a longitudinal axis and a head end that is inwardly directed toward the second baseplate;
a second baseplate, having an outwardly facing surface and an inwardly facing surface having a curvate pocket formed by a central portion of the second baseplate’s inwardly facing surface concaving outwardly to define a semispherical contour;
a convex structure having an outwardly facing surface and an inwardly facing surface, the convex structure further having a central bore extending from the convex structure’s inwardly facing surface to the convex structure’s outwardly facing surface, the central bore being tapered to a larger diameter toward the convex structure’s inwardly facing surface and having an opening on the convex structure’s outwardly facing surface that is surrounded by a curvate taper defining a semispherical contour, the convex structure further having a protrusion adjacent the curvate taper; and
a ball defining a spherical contour, the ball having a curvate recess having boundaries, the ball further having a central bore; wherein
the ball is seatable in the curvate pocket; and wherein
the convex structure’s outwardly facing surface is securable to the second baseplate, the securing of the convex structure to the second baseplate establishing a curvate socket formed by the second baseplate’s curvate pocket and the convex structure’s curvate taper, the curvate socket defining a spherical contour, into which curvate socket the convex structure’s protrusion extends; and wherein
the ball is thereby capturable in the curvate socket, with the curvate socket’s spherical contour accommodating the ball’s spherical contour for rotation and angulation of the ball in the curvate socket about a central portion of the ball, and with the ball’s curvate recess accommodating the convex structure’s protrusion such that the ball’s curvate recess’s boundaries define limits of rotation of the ball within the curvate socket in that the ball’s rotation within the curvate socket is limited by interference between the protrusion and the boundaries, and such that the boundaries accommodate angulation of the ball within the curvate socket; and wherein
the post is disposable through the convex structure’s central bore and the post’s head end is securable to the ball’s central bore, such that the post is accommodated for rotation in the convex structure’s central bore about the post’s longitudinal axis as the ball rotates in the curvate socket, and such that the post is accommodated, by the convex structure’s central bore being tapered, for angulation therein about the ball’s central portion, as the ball angulates in the curvate socket; and wherein
the second baseplate includes a first part having the inwardly facing surface having the curvate pocket of the second baseplate, and a second part having the outwardly facing surface; and further comprising
a spring member disposed between the first part and the second part such that a compressive load applied to the outwardly facing surfaces of the baseplates is borne by the spring member.
20. The artificial intervertebral disc of claim 19, wherein each of the inwardly facing surface of the first baseplate and the inwardly facing surface of the convex structure has a respective perimeter region, and the ball’s curvate recess’s boundaries accommodate angulation of the ball within the curvate socket at least until the perimeter regions meet, and the post is accommodated, by the convex structure’s central bore being tapered, for angulation in the convex structure’s central bore about the ball’s central portion, as the ball angulates in the curvate socket, at least until the perimeter regions meet.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A phase difference detection circuit that detects a phase difference between at least two signals and outputs a phase difference signal indicating the detected phase difference, said at least two signals being obtained by summing predetermined signals among a plurality of signals input to the phase difference detection circuit, said phase difference detection circuit comprising:
a phase difference correction circuit that detects and stores the phase difference between the at least two signals at a predetermined timing;
wherein
when the detected phase difference is greater than an upper limit of a phase difference window, the phase difference correction circuit corrects the detected phase difference to be the upper limit and outputs the corrected phase difference, and when the detected phase difference is less than a lower limit of the phase difference window, the phase difference correction circuit corrects the detected phase difference to be the lower limit and outputs the corrected phase difference, said phase difference window being defined in a range from said lower limit to said upper limit, said upper limit and said lower limit being defined to be an average value of a plurality of said stored phase differences plus and minus a predetermined value, respectively.
2. A phase difference detection circuit that detects a plurality of phase differences between predetermined signals among a plurality of signals input to the phase difference detection circuit, outputs a plurality of phase difference signals each indicating one of the detected phase differences, sums predetermined signals of the phase difference signals, and outputs the summed signal, said phase difference detection circuit comprising:
a phase difference correction circuit that detects and stores the phase differences at predetermined timings;
wherein
when the detected phase difference is greater than an upper limit of a phase difference window, the phase difference correction circuit corrects the detected phase difference to be the upper limit and outputs the corrected phase difference, and when the detected phase difference is less than a lower limit of the phase difference window, the phase difference correction circuit corrects the detected phase difference to be the lower limit and outputs the corrected phase difference, said phase difference window being defined in a range from said lower limit to said upper limit, said upper limit and said lower limit being defined to be an average value of a plurality of said stored phase differences plus and minus a predetermined value, respectively.
3. The phase difference detection circuit as claimed in claim 1, wherein
the phase difference correction circuit comprises a digital circuit; and
the phase difference signal is a digital signal.
4. The phase difference detection circuit as claimed in claim 1, wherein the phase difference correction circuit prohibits storage of the detected phase difference when the detected phase difference is out of the phase difference window.
5. The phase difference detection circuit as claimed in claim 1, wherein
the phase difference correction circuit converts the at least two signals into digital signals, respectively; and
the phase difference correction circuit prohibits storage of the detected phase difference between the at least two signals when a pulse length of at least one of the digital signals is less than a predetermined value.
6. The phase difference detection circuit as claimed in claim 1, wherein
the phase difference correction circuit sets the range of the phase difference window to be a predetermined value W1 when the output phase difference is within a predetermined range, and sets the range of the phase difference window to be a predetermined value W2 greater than W1 when the output phase difference is out of the predetermined range.
7. The phase difference detection circuit as claimed in claim 1, wherein
the phase difference correction circuit sets the range of the phase difference window to be a predetermined value W1 when the phase difference before the correction is within a predetermined range, and sets the range of the phase difference window to be a predetermined value W2 greater than W1 when the phase difference before the correction is out of the predetermined range, said predetermined range being defined based on the average value.
8. The phase difference detection circuit as claimed in claim 4, further including a conversion circuit that converts the at least two signals into digital signals, respectively,
wherein
the phase difference correction circuit comprises:
a phase comparison circuit that compares phases of the digital signals output from the conversion circuit, and outputs a signal indicating a comparison result;
a phase difference generation circuit that detects a phase difference between the at least two signals from the signals output from the phase comparison circuit, and generates and outputs a signal indicating the detected phase difference;
a phase difference storage circuit that stores the phase difference detected in the phase difference generation circuit; and
a phase difference window generation circuit that calculates the average value of the phase differences stored by the phase difference storage circuit, and generates the phase difference window by adding the predetermined value to the average value and subtracting the predetermined value from the average value; wherein
the phase difference generation circuit receives the phase difference window from the phase difference window generation circuit, corrects the detected phase difference by using the phase difference window, and prohibits storage of the detected phase difference in the phase difference storage circuit when the detected phase difference is out of the phase difference window.
9. The phase difference detection circuit as claimed in claim 5, further including a conversion circuit that converts the at least two signals into digital signals, respectively,
wherein
the phase difference correction circuit comprises:
a pulse length detection circuit that detects pulse lengths of the at least two digital signals output from the conversion circuit;
a phase comparison circuit that compares phases of the digital signals output from the conversion circuit, and outputs a signal indicating a comparison result;
a phase difference generation circuit that detects a phase difference between the at least two signals from the signals output from the phase comparison circuit, and generates and outputs a signal indicating the detected phase difference;
a phase difference storage circuit that stores the phase difference detected by the phase difference generation circuit; and
a phase difference window generation circuit that calculates the average value of the phase differences stored in the phase difference storage circuit, and generates the phase difference window by adding the predetermined value to the average value and subtracting the predetermined value from the average value; wherein
the phase difference generation circuit receives the phase difference window from the phase difference window generation circuit, corrects the detected phase difference by using the phase difference window, and prohibits storage of the detected phase difference in the phase difference storage circuit when the pulse length of at least one of the digital signals detected by the pulse length detection circuit is less than a predetermined value.
10. The phase difference detection circuit as claimed in claim 8, wherein t
he phase difference correction circuit further comprises:
a determination circuit that determines whether the output phase difference is within the predetermined range; and
a window range modification circuit that modifies the range of the phase difference window in the phase difference window generation circuit in response to a determination result from the determination circuit; wherein
the window range modification circuit sets the range of the phase difference window to be a predetermined value W1 when the determination circuit determines that the output phase difference is within the predetermined range, and sets the range of the phase difference window to be a predetermined value W2 greater than W1 when the determination circuit determines that the output phase difference is out of the predetermined range.
11. The phase difference detection circuit as claimed in claim 8, wherein
the phase difference correction circuit further comprises:
a determination circuit that determines whether the phase difference before the correction is within the predetermined range; and
a window range modification circuit that modifies the range of the phase difference window in the phase difference window generation circuit in response to a determination result from the determination circuit; wherein
the window range modification circuit sets the range of the phase difference window to be a predetermined value W1 when the determination circuit determines that the phase difference before the correction is within the predetermined range, and sets the range of the phase difference window to be a predetermined value W2 greater than W1 when the determination circuit determines that the phase difference before the correction is out of the predetermined range.
12. An optical disk device for recording and reproducing data in an optical disk, comprising:
a phase difference detection circuit that detects a phase difference between at least two signals and outputs a phase difference signal indicating the detected phase difference, said at least two signals being obtained by summing predetermined signals among a plurality of signals output from a plurality of light receiving elements that receive reflected light of a laser beam incident on a recording plane of the optical disk;
wherein
the phase difference detection circuit includes a phase difference correction circuit that detects and stores the phase difference between the at least two signals at a predetermined timing,
when the detected phase difference is greater than an upper limit of a phase difference window, the phase difference correction circuit corrects the detected phase difference to be the upper limit and outputs the corrected phase difference, and when the detected phase difference is less than a lower limit of the phase difference window, the phase difference correction circuit corrects the detected phase difference to be the lower limit and outputs the corrected phase difference, said phase difference window being defined in a range from said lower limit to said higher limit, said upper limit and said lower limit being defined to be an average value of a plurality of said stored phase differences plus and minus a predetermined value, respectively.
13. An optical disk device for recording and reproducing data in an optical disk, comprising:
a phase difference detection circuit that detects a plurality of phase differences between predetermined signals among a plurality of signals output from a plurality of light receiving elements that receive reflected light of a laser beam incident on a recording plane of the optical disk, outputs a plurality of phase difference signals each indicating one of the detected phase differences, sums predetermined signals of the phase difference signals, and outputs the summed signal;
wherein
the phase difference detection circuit includes a phase difference correction circuit that detects and stores the phase differences at predetermined timings,
when the detected phase difference is greater than an upper limit of a phase difference window, the phase difference correction circuit corrects the detected phase difference to be the upper limit and outputs the corrected phase difference, and when the detected phase difference is less than a lower limit of the phase difference window, the phase difference correction circuit corrects the detected phase difference to be the lower limit and outputs the corrected phase difference, said phase difference window being defined in a range from said lower limit to said upper limit, said upper limit and said lower limit being defined to be an average value of a plurality of said stored phase differences plus and minus a predetermined value, respectively.
14. The optical disk device as claimed in claim 12, wherein
the phase difference correction circuit comprises a digital circuit; and
the phase difference signal is a digital signal.
15. The optical disk device as claimed in claim 12, wherein the phase difference correction circuit prohibits storage of the detected phase difference when the detected phase difference is out of the phase difference window.
16. The optical disk device as claimed in claim 12, wherein
the phase difference correction circuit converts the at least two signals into digital signals, respectively; and
the phase difference correction circuit prohibits storage of the detected phase difference between the at least two signals when a pulse length of at least one of the digital signals is less than a predetermined value.
17. The optical disk device as claimed in claim 12, wherein
the phase difference correction circuit sets the range of the phase difference window to be a predetermined value W1 when the output phase difference is within a predetermined range, and sets the range of the phase difference window to be a predetermined value W2 greater than W1 when the output phase difference is out of the predetermined range.
18. The optical disk device as claimed in claim 12, wherein
the phase difference correction circuit sets the range of the phase difference window to be a predetermined value W1 when the phase difference before the correction is within a predetermined range, and sets the range of the phase difference window to be a predetermined value W2 greater than W1 when the phase difference before the correction is out of the predetermined range, said predetermined range being defined based on the average value.