1. An apparatus generating a clock signal, the apparatus comprising:
a voltage controlled oscillator which generates a clock signal of a frequency that varies with a control voltage signal;
a phase compensator which receives an input signal and the clock signal, detects a phase difference between the input signal and the clock signal, and generates a first control voltage corresponding to the phase difference;
a frequency compensator which receives the input signal and the clock signal, detects a frequency difference between the input signal and the clock signal, and generates a second control voltage corresponding to the frequency difference; and
an adder which sums the first control voltage and the second control voltage and generates the control voltage signal, wherein the frequency compensator comprises a booster which boosts a high-frequency component of the input signal.
2. The apparatus of claim 1, wherein the input signal is a radio frequency (RF) signal read from data recorded onto an optical disk.
3. The apparatus of claim 1, wherein the phase compensator comprises:
a phase detector which receives the input signal and the clock signal and detects a phase difference between the input signal and the clock signal; and
a loop filter which filters an output of the phase detector and outputs the first control voltage corresponding to the phase difference.
4. The apparatus of claim 1, wherein the frequency compensator comprises a binarizer which converts the input signal into a digital signal.
5. The apparatus of claim 1, wherein the frequency compensator further comprises:
a first maximum period detector which counts the number of clock signals within each section where the input signal is positive (+) and outputs a first maximum period for a predetermined amount of time;
a second maximum period detector which counts the number of clock signals within each section where the input signal is negative (\u2212) and outputs a second maximum period for the predetermined amount of time;
a maximum period detector which receives the first maximum period and the second maximum period and determines whether the input signal has an error; and
a frequency error generator which compares the output signal of the maximum period detector with a predetermined value and generates a control voltage corresponding to the difference between the output signal and the predetermined value.
6. The apparatus of claim 5, wherein the predetermined value is a period of 14T of a sync signal of a digital versatile disk (DVD).
7. The apparatus of claim 5, wherein when the difference between the first maximum period and the second maximum period is less than a predetermined range, the maximum period detector outputs either the first maximum period or the second maximum period or an average value of the first maximum period and the second maximum period.
8. The apparatus of claim 5, wherein the maximum period detector additionally receives a signal of a period of T, counts the number of clock signals within each section where the signal is positive (+) or negative (\u2212), compares the count value with the first maximum period or the second maximum period, and outputs one of the count values, the first maximum period, or the second maximum period or an average value of the count value and the first maximum period or an average value of the count value and the second maximum period.
9. A frequency compensation apparatus comprising:
a first maximum period detector which counts a number of clock signals within each section where an input signal is positive (+) and outputs a first maximum period for a predetermined amount of time;
a second maximum period detector which counts the number of clock signals within each section where the input signal is negative (\u2212) and outputs a second maximum period for the predetermined amount of time;
a maximum period detector which receives a first maximum period and a second maximum period and determines whether the input signal has an error; and
a frequency error generator which compares an output signal of the maximum period detector with a predetermined value and generates a control voltage corresponding to a difference between the output signal and the predetermined value.
10. The frequency compensation apparatus of claim 9, wherein when a difference between the first maximum period and the second maximum period is less than a predetermined range, the maximum period detector outputs either the first maximum period or the second maximum period or an average value of the first maximum period and the second maximum period.
11. The frequency compensation apparatus of claim 9, wherein the maximum period detector additionally receives a signal of a period of T, counts the number of clock signals within each section where the signal is positive (+) or negative (\u2212), compares a count value with the first maximum period or the second maximum period, and outputs one of the count value, the first maximum period, or the second maximum period or an average value of the count value and the first maximum period or an average value of the count value and the second maximum period.
12. A method of generating a clock signal, the method comprising:
generating a first clock signal of a frequency that varies with a control voltage signal;
receiving an input signal and the first clock signal, detecting a phase difference between the input signal and the first clock signal, and outputting a first control voltage corresponding to the phase difference;
receiving the input signal and the first clock signal, detecting a frequency difference between the input signal and the first clock signal, and outputting a second control voltage corresponding to the frequency difference; and
controlling the frequency of the first clock signal based on the control voltage signal generated by summing the first control voltage and the second control voltage and generating a second clock signal, wherein the outputting of the second control voltage corresponding to the frequency difference comprises receiving the clock signal and a signal generated by boosting a high-frequency component of the input signal, detecting a frequency difference between the clock signal and the signal, and outputting the second control voltage corresponding to the frequency difference.
13. The method of claim 12, wherein the input signal is a radio frequency (RF) signal read from data recorded onto an optical disk.
14. The method of claim 12, wherein the outputting of the first control voltage corresponding to the phase difference comprises:
receiving the input signal and the first clock signal and detecting the phase difference between the input signal and the first clock signal; and
filtering the output of the phase detector and outputting the first control voltage corresponding to the phase difference.
15. The method of claim 12, wherein the outputting of the second control voltage corresponding to the frequency difference comprises:
counting a number of clock signals within each section where the input signal is positive (+) and outputting a first maximum count value for a predetermined amount of time;
counting a number of clock signals within each section where the input signal is negative (\u2212) and outputting a second maximum count value for a predetermined amount of time;
receiving, a first maximum period and a second maximum period and determining whether the input signal has an error; and
comparing an output signal of the maximum period detecting unit with a predetermined value and generating a control voltage corresponding to the difference between the output signal and the predetermined value.
16. The method of claim 15, wherein the predetermined value is a period of 14T of a sync signal of a digital versatile disk (DVD).
17. The method of claim 15, wherein when the difference between the first maximum period and the second maximum period is less than a predetermined range, outputting either the first maximum period or the second maximum period or an average value of the first maximum period and the second maximum period.
18. The method of claim 15, wherein in addition to receiving, a first maximum period and a second maximum period and determining whether the input signal has an error, receiving a signal of a period of T, counting the number of clock signals within each section where the signal is positive (+) or negative (\u2212), comparing the count value with the first maximum period or the second maximum period, and outputting one of the count value, the first maximum period, or the second maximum period or an average value of the count value and the first maximum period or an average value of the count value and the second maximum period if the difference between the count value and the first maximum period or the second maximum period is less than the predetermined value.
19. A frequency compensation method comprising:
counting a number of clock signals within each section where an input signal is positive (+) or negative (\u2212) and outputting a maximum positive count value and a maximum negative count value;
comparing the maximum positive count value with the maximum negative count value; and
if the difference between the maximum positive count value and the maximum negative count value is below a predetermined value, outputting either the maximum positive count value or the maximum negative count value or an average value of the maximum positive count value and the maximum negative count value.
20. A computer readable recording medium having embodied thereon a computer program for a method of generating a clock signal, wherein the method comprises:
generating a first clock signal of a frequency that varies with a control voltage signal;
receiving an input signal and the first clock signal, detecting a phase difference between the input signal and the first clock signal, and outputting a first control voltage corresponding to the phase difference;
receiving the input signal and the first clock signal, detecting a frequency difference between the input signal and the first clock signal, and outputting a second control voltage corresponding to the frequency difference; and
controlling the frequency of the first clock signal based on the control voltage signal generated by summing the first control voltage and the second control voltage and generating a second clock signal, wherein the outputting of the second control voltage corresponding to the freguency difference comprises receiving the clock signal and a signal generated by boosting a high-freguency component of the input signal, detecting a freguency difference between the clock signal and the signal, and outputting the second control voltage corresponding to the freguency difference.
21. The computer readable recording medium according to claim 20, wherein the computer program is stored in a magnetic tape, a hard disk, a floppy disk, a flash memory, an optical storage media or a carrier wave.
22. The computer readable recording medium according to claim 20, wherein the computer program is distributed over a computer system connected via a network, and the computer program is stored and implemented as a computer readable code using a distribution technique.
23. A computer readable recording medium having embodied thereon a computer program for a frequency compensation method, wherein the frequency compensation method comprises:
counting a number of clock signals within each section where the signal is positive (+) or negative (\u2212), and outputting a maximum positive count value and a maximum negative count value;
comparing the maximum positive count value with the maximum negative count value; and
if the difference between the maximum positive count value and the maximum negative count value is below a predetermined value, outputting either the maximum positive count value or the maximum negative count value or an average value of the maximum positive count value and the maximum negative count value.
24. The computer readable recording medium according to claim 23, wherein the computer program is stored in a magnetic tape, a hard disk, a floppy disk, a flash memory, an optical storage media or a carrier wave.
25. The computer readable recording medium according to claim 23, wherein the computer program is distributed over a computer system connected via a network, and the computer program is stored and implemented as a computer readable code using a distribution technique.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1 . A shoe for use in a swash plate type compressor, interposed between a swash plate and a piston, the shoe comprising:
a base member made of aluminum alloy; and
a metal plating layer coating at least a part of surface of the base member;
wherein the thickness of the metal plating layer ranges from 20 m to 150
2. The shoe for use in the swash plate type compressor according to claim 1, wherein the metal plating layer coats at least a sliding portion with respect to the swash plate.
3. The shoe for use in the swash plate type compressor according to claim 1, wherein the metal plating layer coats the entire surface of the base member.
4. The shoe for use in the swash plate type compressor according to claim 1, wherein the thickness of the metal plating layer ranges from 30 m to 120 m.
5. The shoe for use in the swash plate type compressor according to claim 4, wherein the thickness of the metal plating layer is 40 m or above.
6. The shoe for use in the swash plate type compressor according to claim 5, wherein the thickness of the metal plating layer is 50 m or above.
7. The shoe for use in the swash plate type compressor according to claim 6, wherein the thickness of the metal plating layer is 70 m or above.
8. The shoe for use in the swash plate type compressor according to claim 7, wherein the thickness of the metal plating layer is 100 m or above.
9. The shoe for use in the swash plate type compressor according to claim 1, wherein the hardness of the metal plating layer is 300 Hv or above.
10. The shoe for use in the swash plate type compressor according to claim 1, wherein the metal plating layer is formed by electroless plating.
11. The shoe for use in the swash plate type compressor according to claim 10, wherein the metal plating layer is formed by one of electroless plating eutectic with nickel, electroless plating with cobalt eutectic with phosphorus, and hard chrome plating.
12. The shoe for use in the swash plate type compressor according to claim 11, wherein the metal plating layer is formed by electroless plating with nickel eutectic with phosphorus.
13. The shoe for use in the swash plate type compressor according to claim 1, wherein the metal plating layer includes a plurality of layers including at least an outermost layer for forming the surface of the metal plating layer.
14. The shoe for use in the swash plate type compressor according to claim 13, wherein the hardness of at least the outermost layer is 3OOHv or above.
15. The shoe for use in the swash plate type compressor according to claim 14, wherein at least the outermost layer is formed by electroless plating with nickel.
16. The shoe for use in the swash plate type compressor according to claim 13, wherein at least the outermost layer contains a solid lubricant.
17. The shoe for use in the swash plate type compressor according to claim 16, wherein the solid lubricant includes at least one of molybdenum disulfide, boron nitride, tungsten disulfide, graphite and polytetrafluoroethylene.
18. The shoe for use in the swash plate type compressor according to claim 1, wherein the metal plating layer includes an outermost layer forming the surface of the metal plating layer and an inner layer between the outermost layer and the base member.
19. The shoe for use in the swash plate type compressor according to claim 18, wherein the outermost layer is formed by electroless plating with nickel eutectic with phosphorus and boron, and the inner layer is formed by electroless plating with nickel eutectic with phosphorus.
20. The shoe for use in the swash plate type compressor according to claim 19, wherein the outermost layer is formed by electroless plating with nickel eutectic with phosphorus, boron and tungsten.
21. The shoe for use in the swash plate type compressor according to claim 19, wherein the inner layer is formed by electroless plating with nickel.
22. The shoe for use in the swash plate type compressor according to claim 18, wherein the outermost layer is thicker than the inner layer.
23. The shoe for use in the swash plate type compressor according to claim 18, wherein the inner layer is thicker than the outermost layer.
24. The shoe for use in the swash plate type compressor according to claim 18, wherein the outermost layer contains a solid lubricant.
25. The shoe for use in the swash plate type compressor according to claim 24, wherein the solid lubricant includes at least one of molybdenum disulfide, boron nitride, tungsten disulfide, graphite and polytetrafluoroethylene.
26. The shoe for use in the swash plate type compressor according to claim 1 further comprising:
a lubricant layer made of synthetic resin containing a solid lubricant, the lubricant layer coating at least a part of surface of the metal plating layer.
27. The shoe for use in the swash plate type compressor according to claim is 26, wherein the synthetic resin includes at least one of polyamideimide, epoxy resin, polyether ketone and phenolic resin.
28. The shoe for use in the swash plate type compressor according to claim 26, wherein the solid lubricant includes at least one of molybdenum disulfide, boron nitride, tungsten disulfide, graphite and polytetrafluoroethylene.
29. A swash plate type compressor comprising:
a housing;
a drive shaft rotatably supported by the housing;
a swash plate operatively connected to the drive shaft;
a piston accommodated in the housing, the piston operatively connected to the swash plate; and
a pair of shoes interposed between the swash plate and the piston, each of the shoes including:
a base member made of aluminum alloy; and
metal plating layer coating at least a part of surface of the base member;
wherein the thickness of the metal plating layer ranges from 20 m to 150m.
30. The swash plate type compressor according to claim 29, wherein the swash plate is made of iron series.
31. The swash plate type compressor according to claim 29, wherein the swash plate further includes a lubricant layer on a surface sliding with respect to the shoe.
32. The swash plate type compressor according to claim 31, wherein the swash plate further includes a metal spraying coating layer made of one of aluminum, copper and alloys of them, the metal spraying coating layer is formed on the surface sliding with respect to the shoe, and the lubricant layer is formed on the surface of the metal spraying coating layer.
33. The swash plate type compressor according to claim 29, wherein the swash plate is made of iron series, and the surface sliding with respect to the shoe is hardened by quenching.