1. A method for operating an optical drive system (9) capable of reproducingrecording information fromto an optical carrier (1), wherein the optical drive system comprises:
a radiation source (5) for generating a radiation beam,
a focusing means (3) for focussing the radiation beam,
an optical receiver means (6) for generating an electric read signal in response to radiation reflected from the optical carrier (1),
a focus tracking system (4, 7, 9) for tracking the carrier (1) with said focussed radiation beam (2),
wherein said focus tracking system comprises
a focus error generating means (7) for generating a focus error signal (FE),
a focus actuator means (4) for changing a focus position of said focussed radiation beam (2) relative to the optical carrier (1), said focus actuator means (4) being driven by a supplied correction signal (CS), and
a correction signal generating means (9) comprising
a focus controller means (PID) for controlling said focus actuator, and, said focus controller means being supplied with said focus error signal (FE), and
a focus memory loop (ML) for applying a stored correction signal to said focus actuator,
the method comprises the steps of
a) determine if an event has occurred that requires at least a gradual stop of said focus tracking system (4, 7, 9), and if positive then,
b) disable the focus controller means (PID) by opening the control loop,
c) gradually reducing a memory loop parameter of said focus memory loop (ML), said parameter corresponding to an amplitude of said stored correction signal,
and optionally,
d) gradually reducing a controller parameter of an integrating means (I) of said focus controller means (PID), said parameter corresponding to a focus offset position.
2. A method according to claim 1, wherein said stored correction signal is maintained in the memory loop (ML) during at least the duration of step c of gradually reducing said memory parameter.
3. A method according to claim 1, wherein the occurrence of said event of step a is an event selected from the group comprising: An ejection of the carrier from the optical drive system, a stop of recordingreading of the carrier, and a stop of spinning the carrier.
4. A method according to claim 1, wherein the step d of gradually reducing of a controller parameter of the integrating means (I) of said focus controller means (PID) is achieved by gradually leaking away electric charge of an integrator part of the focus controller means (PID), said integrator part (I) having a value corresponding to a focus offset position.
5. A method according to claim 1, wherein the step d of gradually reducing of a controller parameter of the integrating means (I) of said focus controller means (PID) is achieved by gradually reducing a digitally controlled parameter of the integrator part (I) of the focus controller means (PID), said digitally controlled parameter having a value corresponding to a focus offset position.
6. A method according to claim 4 or 5, wherein said controller parameter indicative of a focus offset position is gradually reduced or gradually increased to a negative or positive value, respectively, so as to move the focussing means (3) further away from the optical carrier (1).
7. A method according to claim 1, wherein the step c of gradually reducing a memory loop parameter of an amplifier means (AML) of said focus memory loop (ML), is achieved by gradually reducing the amplification of said stored focus control signal being applied to said focus actuator.
8. A method according to claim 1, wherein a phase of said stored correction signal applied to said focus actuator (4) is substantially synchronized with the angular position of said optical carrier (1).
9. A method according to claim 1, wherein the period of time in which said memory loop parameter of said amplifier means (AML) of said focus memory loop (ML) is reduced a certain amount, andor the period of time in which said controller parameter of said integrating means (I) of said focus controller means (PID) is reduced a certain amount, is adapted to be longer than the reciprocal value of the lowest natural frequency of said focus actuator means (4).
10. An apparatus for operating an optical drive system (12) capable of reproducingrecording information fromto an associated optical carrier (1), wherein the apparatus comprises:
a radiation source (5) for generating a radiation beam,
a focusing means (3) for focussing the radiation beam,
an optical receiver means (6) for generating an electric read signal in response to radiation reflected from the optical carrier (1),
a focus tracking system (4, 7, 9) for tracking the carrier (1) with said focussed radiation beam (2),
wherein said focus tracking system comprises
a focus error generating means (7) for generating a focus error signal (FE),
a focus actuator means (4) for changing a focus position of said focussed radiation beam (2) relative to the optical carrier (1), said focus actuator means (4) being driven by a supplied correction signal (CS), and
a correction signal generating means (9) comprising
a focus controller means (PID) for controlling said focus actuator, and, said focus controller means being supplied with said focus error signal (FE), and
a focus memory loop (ML) for applying a stored correction signal to said focus actuator,
and the apparatus further comprises:
a) event detection means for generating a signal indicative of the occurrence of an event that requires at least a gradual stop of said focus tracking system (4, 7, 9),
b) switching means (33) for disabling the focus controller means (PID) by opening the control loop,
c) adjusting means (29) for gradually reducing a memory loop parameter of said focus memory loop (ML), said parameter corresponding to an amplitude of said stored correction signal,
and optionally,
d) adjusting means (31,32) for reducing a controller parameter of an integrating means (I) of said focus controller means (PID), said parameter corresponding to a focus offset position.
11. A computer program product being adapted to enable a computer system comprising at least one computer having data storage means associated therewith to control an optical drive system according to the operating method as claimed in claim 1.
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 turbocharger comprising:
a compressor assembly;
a center housing assembly;
a turbine assembly that comprises a control arm that controls position of a wastegate plug with respect to a wastegate seat;
a control linkage operatively coupled to the control arm;
an actuator operatively coupled to the control linkage for translation of the control linkage along a control linkage axis; and
a biasing mechanism wherein the control linkage comprises a notch, wherein the biasing mechanism couples to the control linkage at the notch, and wherein the biasing mechanism applies an off-axis force to the control linkage.
2. The turbocharger of claim 1 wherein the biasing mechanism comprises a spring.
3. The turbocharger of claim 1 comprising a bracket mounted to at least one of the compressor assembly, the center housing assembly and the turbine assembly wherein the biasing mechanism is operatively coupled to the bracket.
4. The turbocharger of claim 3 wherein the biasing mechanism comprises a coil spring.
5. An assembly comprising:
a turbine housing that comprises a bore, a wastegate seat and a wastegate passage that extends to the wastegate seat;
a bushing configured for receipt by the bore;
a rotatable wastegate shaft configured for receipt by the bushing;
a wastegate plug extending from the wastegate shaft;
a control arm operatively coupled to the wastegate shaft;
a control linkage operatively coupled to the control arm wherein the control linkage comprises a control axis;
an actuator operatively coupled to the control linkage for translation of the control linkage in a direction of the control axis; and
a biasing mechanism wherein the control linkage comprises a notch, wherein the biasing mechanism couples to the control linkage at the notch, and wherein the biasing mechanism applies an off-axis force to the control linkage.
6. The assembly of claim 5 further comprising a compressor housing that comprises a bracket wherein the biasing mechanism is operatively coupled to the bracket.
7. The assembly of claim 5 comprising another biasing mechanism operatively coupled to the control linkage.
8. The assembly of claim 5 comprising a biasing cam operatively coupled to the wastegate shaft.
9. The assembly of claim 5 wherein translation of the control linkage in a direction of the control axis positions the wastegate plug in an open state with respect to the wastegate seat.
10. The assembly of claim 5 wherein translation of the control linkage in a direction of the control axis positions the wastegate plug in a closed state with respect to the wastegate seat.
11. The assembly of claim 5 wherein the control linkage comprises a control rod.
12. The assembly of claim 5 wherein the actuator comprises an electric actuator.
13. The assembly of claim 5 wherein the biasing mechanism comprises a spring.
14. The assembly of claim 13 wherein the spring comprises a coil spring.
15. The assembly of claim 5 further comprising a center housing.
16. The assembly of claim 15 further comprising a compressor housing.
17. The assembly of claim 16 comprising a bracket mounted to at least one of the turbine housing, the center housing and the compressor housing, the biasing mechanism being operatively coupled to the bracket.
18. The assembly of claim 5 comprising a peg that extends from the control arm wherein the control linkage is operatively coupled to the peg.
19. The assembly of claim 18 wherein the control linkage comprises a coupler that receives the peg.
20. An assembly comprising:
a turbine housing that comprises a bore, a wastegate seat and a wastegate passage that extends to the wastegate seat;
a bushing disposed at least in part in the bore;
a rotatable wastegate shaft received at least in part by the bushing;
a wastegate plug that extends from the wastegate shaft;
a control arm operatively coupled to the wastegate shaft;
a control linkage operatively coupled to the control arm wherein the control linkage comprises a control axis and a notch;
an actuator, operatively coupled to the control linkage, that translates the control linkage in a direction of the control axis; and
a spring that couples to the control linkage via the notch wherein the spring applies an off-axis force to the control linkage.
21. An assembly comprising:
a turbine housing that comprises a bore, a wastegate seat and a wastegate passage that extends to the wastegate seat;
a bushing disposed at least in part in the bore;
a rotatable wastegate shaft received at least in part by the bushing;
a wastegate plug that extends from the wastegate shaft;
a control arm operatively coupled to the wastegate shaft;
a control linkage operatively coupled to the control arm wherein the control linkage comprises a control axis and an opening;
an actuator, operatively coupled to the control linkage, that translates the control linkage in a direction of the control axis; and
a spring that couples to the control linkage via the opening wherein the spring applies an off-axis force to the control linkage.