1. An optical option attachment ring comprising:
a ring body that connects one end to the other end, receives a lens barrel, and has a predetermined gap between the one end and the other end;
a fastening screw that is inserted into screw holes that pass through the one end and the other end;
a rotator having an abutting surface that projects inward from the inner circumferential surface of the ring body and abuts the front end of the lens barrel as well as an arcuate portion that follows the upper end of the abutting surface;
a resilient member that applies an urging force to the rotator such that the rotator rotates in the direction opposite to an insertion direction of the lens barrel; and
a stopper that abuts at least one of the one end and the other end so as to restrict the rotation caused by urging force of the resilient member, wherein
the one end and the other end, the ring body and the fastening screw are configured such that tightening the fastening screw brings the one end and the other end closer to each other and hence the diameter of the ring body decreases so that the optical option attachment ring is fastened to the lens barrel, while loosening the fastening screw separates the one end and the other end from each other and hence the diameter of the ring body increases so that the optical option attachment ring disengages from the lens barrel,
the rotator is configured such that when the lens barrel is inserted into the ring body and moved to a predetermined position, the front end of the lens barrel abuts the abutting surface and the front end of the lens barrel moves relative to the abutting surface so as to rotate the rotator, so that the abutting surface and the arcuate portion are situated outside the inner circumferential surface of the ring body, and
when the lens barrel is inserted into the ring body and moved to the predetermined position, the urging force of the resilient member rotates the rotator so that the abutting surface and the arcuate portion are situated in a groove formed in the lens barrel.
2. The optical option attachment ring according to claim 1, wherein
the rotator is provided with an opening into which the fastening screw is inserted, and the rotator is disposed between the one end and the other end, and rotatably held around the inserted fastening screw.
3. The optical option attachment ring according to claim 1, wherein
the rotator has a small arcuate portion that follows the lower end of the abutting surface and is smaller than the arcuate portion.
4. The optical attachment ring according to claim 2, wherein the rotator has a small arcuate portion that follows the lower end of the abutting surface and is smaller than the arcuate portion.
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 method of controlling transmission power in a mobile station which is used in a CDMA cellular mobile radio communication system, said CDMA cellular mobile radio communication system comprising a plurality of base stations each of which transmits a pilot signal pre-assigned to each base station and a control signal for power control of the mobile station, said mobile station successively controlling transmission power in response to the control signal sent from each of the base stations during communication with the base stations, comprising the steps of:
periodically detecting, in the mobile station, a level of each pilot signal sent from the plurality of the base stations;
checking out whether or not the mobile station is being connected to the plurality of the base stations;
discriminating between a first group of the base stations under connection and a second group of the base stations under non-connection;
comparing a first reception level of the pilot signals concerned with the first group of the base stations with a second reception level of the pilot signals concerned with the second group of the base stations to determine whether or not the first reception level is higher than the second reception level; and
suppressing an increase of the transmission power in the mobile station when the second reception level exceeds the first reception level.
2. A method as claimed in claim 1, wherein the detecting step is periodically carried out in the mobile station.
3. A method of controlling transmission power in a CDMA cellular mobile radio communication system which comprises a plurality of base stations each of which transmits a pilot signal preassigned to each base station and a plurality of mobile stations communicable with the base stations, each of the mobile stations comprising first transmission power control means for adjusting the transmission power on the basis of a reception level concerned with the pilot signals and second transmission power control means for controlling the transmission power by a control step size on the basis of a control instruction sent from the base stations under connection, comprising the steps of:
receiving the pilot signals from the plurality of the base stations;
determining the transmission power in inverse proportion to a maximum one of reception levels of the pilot signals;
judging whether or not a first reception level of the pilot signals concerned with the base stations under connection exceeds a second reception level of the pilot signals concerned with the base stations under non-connection to produce a result of judgement; and
changing the control step size from one to another when the second reception level exceeds or does not exceed the first reception level.
4. A method as claimed in claim 3, wherein the changing step comprises the steps of:
decreasing the control step size when the second reception level exceeds the first reception level; and
increasing the control step size when the second reception level does not exceed the first reception level.
5. A method as claimed in claim 3, wherein the changing step comprises the steps of:
rendering the control step size into a small step size for an increase of the transmission power when the second reception level exceeds the first reception level; and
rendering the control step size into a large step size for a decrease of the transmission power when the second reception level does not exceed the first reception level.
6. A method of controlling transmission power in a CDMA cellular mobile radio communication system which comprises a plurality of base stations each of which transmits a pilot signal pre-assigned to each base station and a plurality of mobile stations communicable with the base stations, each of the mobile stations comprising first transmission power control means for adjusting the transmission power on the basis of a reception level concerned with the pilot signals and second transmission power control means for controlling the transmission power by a control step size on the basis of a control instruction sent from the base stations under connection, comprising the steps of:
receiving the pilot signals from the plurality of the base stations;
determining the transmission power in inverse proportion to a maximum one of reception levels of the pilot signals;
judging whether or not a first reception level of the pilot signals concerned with the base stations under connection exceeds a second reception level of the pilot signals concerned with the base stations under non-connection to produce a result of judgement;
minimizing the transmission power at every time interval for a predetermined time period when the second reception level exceeds the first reception level; and
executing a control operation by the use of the first and the second transmission power control means either during a time period except the predetermined period or when the second reception level does not exceed the first reception level.
7. A method of controlling transmission power in a CDMA cellular mobile radio communication system which comprises a plurality of base stations each of which transmits a pilot signal pre-assigned to each base station and a plurality of mobile stations communicable with the base stations, each of the mobile stations comprising first transmission power control means for adjusting the transmission power on the basis of a reception level concerned with the pilot signals and second transmission power control means for controlling the transmission power by a control step size on the basis of a control instruction sent from the base stations under connection, comprising the steps of:
receiving the pilot signals from the plurality of the base stations;
determining the transmission power in inverse proportion to a maximum one of reception levels of the pilot signals;
judging whether or not a first reception level of the pilot signals concerned with the base stations under connection exceeds a second reception level of the pilot signals concerned with the base stations under non-connection to produce a result of judgement;
decreasing the transmission power in the mobile station by a predetermined amount at every preselected time interval when the second reception level of the pilot signals exceeds the first reception level; and
executing a control operation by the use of the first and the second transmission power control means either during the preselected time interval or when the second reception level does not exceed the first reception level.
8. A method as claimed in claim 3, wherein the transmission power in the first transmission power control means is determined in inverse proportion to a reception level concerned with a whole of the pilot signals.
9. A method as claimed in claim 6, wherein the transmission power in the first transmission power control means is determined in inverse proportion to a reception level concerned with a whole of the pilot signals.
10. A method as claimed in claim 7, wherein the transmission power in the first transmission power control means is determined in inverse proportion to a reception level concerned with a whole of the pilot signals.
11. A method of controlling transmission power in a mobile station in a CDMA cellular mobile radio communication system, comprising the steps of:
detecting each pilot signal level from a plurality of base stations;
checking out whether or not the base stations are under connection to discriminate between a first group of the base stations under connection and a second group of the base stations under non-connection; and
reducing the transmission power in the mobile station to suppress an increase of the transmission power in the mobile station when a first reception level concerned with the first group of the base stations does not exceed a second reception level concerned with the second group of the base stations.
12. A method as claimed in claim 11, wherein the detecting step is periodically carried out in the mobile station.
13. A method of controlling transmission power in a mobile station in a radio communication system which comprise a plurality of base stations, the mobile station being continuously communicable through radio channels with the base stations by executing a hand-off operation during a hand-off time, comprising the steps of:
determining the hand-off time; and
lowering the transmission power in the mobile station during the hand-off time to mitigate interference among the radio channels.
14. A method as claimed in claim 13, wherein the hand-off time detecting step comprises the steps of:
receiving a plurality of constant power signals each of which is sent from each base station at a predetermined power level; and
determining the hand-off time with reference to each reception level of the pilot signals.
15. A method as claimed in claim 14, wherein each of said constant power signals is specified by a pilot signal sent from each base station.
16. A method as claimed in claim 14, wherein the determining step comprises the steps of:
classifying the base stations into a first group base station under connection and a second group base station under non-connection;
comparing a first reception level concerned with the first group base station with a second reception level concerned with the second group base station to judge whether or not the second reception level exceeds the first reception level; and
deciding the band-off time when the second reception level exceeds the first reception level.
17. A method as claimed in claim 13, wherein the radio channels are defined by a common frequency.
18. A method as claimed in claim 1, wherein each of the first and the second reception levels is determined by a weighted sum of the reception levels of the pilot signals.
19. A method as claimed in claim 3, wherein each of the first and the second reception levels is determined by a weighted sum of the reception levels of the pilot signals.
20. A method as claimed in claim 6, wherein each of the first and the second reception levels is determined by a weighted sum of the reception levels of the pilot signals.
21. A method as claimed in claim 7, wherein each of the first and the second reception levels is determined by a weighted sum of the reception levels of the pilot signals.
22. A method as claimed in claim 11, wherein each of the first and the second reception levels is determined by a weighted sum of the reception levels of the pilot signals.
23. A mobile station for use in a communication system which comprise a plurality of base stations, the mobile station being continuously communicable through radio channels with the base stations by executing a hand-off operation during a hand-off time, comprising:
means for determining the handoff time; and
means for lowering the transmission power in the mobile station during the hand-off time to mitigate interference among the radio channels.