1. An image forming apparatus, comprising:
an image bearing member including a surface layer;
electrostatic image forming means for forming an electrostatic image on said surface layer;
developing means, containing at least toner and a carrier, for developing the electrostatic image;
density measuring means for measuring a density of the developed electrostatic image;
layer thickness measuring means for measuring a thickness of the surface layer; and
adjusting means for adjusting toner content in said developing means,
wherein said adjusting means adjusts the toner content on the basis of the thickness of said surface layer measured by said layer thickness measuring means,
wherein said electrostatic image forming means includes means for electrically charging the surface layer,
wherein said layer thickness measuring means measures the thickness of the surface layer by measuring a current passing through said image bearing member via said electrostatic image forming means,
wherein the electrostatic image to be formed at the time of a toner content adjustment is formed in a non-image area of said image bearing member and developed by said developing means which is supplied with a voltage so that a first voltage is applied to the non-image area and a second voltage is applied to an image forming area, and
wherein an amount of change in density of the developed electrostatic image to an amount of change in a toner concentration at the time of applying the first voltage is larger than an amount of change in density of the developed electrostatic image to an amount of change in a toner concentration at the time of applying the second voltage.
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 power tool comprising:
an electronically commutated electric motor having a certain commutation interval, said motor comprising a plurality of exciting windings, said exciting windings being configured in a star connection or in a delta connection;
a drive driven by said motor;
an energy supply device for providing electrical energy;
a controller, the controller comprising a motor controller for activating the motor and further comprising an operating-state recognition module which is configured for detecting at least one operating-state variable and, as a function thereof, for outputting a brake signal;
wherein said controller is configured to initiate, as a function of said brake signal, a braking procedure comprising at least one brake cycle having a certain duration, said brake cycle having a first time segment, wherein the motor is short-circuited, and at least a second time segment,
wherein current is fed to the motor opposite to an original direction of rotation; wherein said duration of said brake cycle corresponds to said commutation interval.
2. The power tool of claim 1, wherein said controller during a brake cycle is configured to initiate a repeated cycling between said first time segment and said second time segment.
3. The power tool of claim 1, wherein said controller during a brake cycle is configured to initiate a repeated cycling between said first time segment, said second time segment and a free-running phase.
4. A power tool comprising:
a motor;
a drive driven by said motor;
an energy supply device for providing electrical energy;
a controller, the controller comprising a motor controller for activating the motor and further comprising an operating-state recognition module which is configured for detecting at least one operating-state variable and, as a function thereof, for outputting a brake signal;
wherein said controller is configured to initiate, as a function of said brake signal, a braking procedure comprising at least one brake cycle, said brake cycle having a first time segment, wherein the motor is short-circuited, and at least a second time segment, wherein current is fed to the motor opposite to an original direction of rotation.
5. The power tool of claim 4, wherein a duration of a brake cycle is formed in total from the sum of the first time segment and the second time segment, said second time segment comprising a maximum of 95% of said duration, preferably a maximum of 75% of said duration.
6. The power tool of claim 4, wherein said first time segment comprises at least 5% of the duration, preferably at least 25% of the duration.
7. The power tool of claim 4, wherein said motor is an electronically commutated electric motor.
8. The power tool of claim 4, wherein said motor has a certain commutation interval, the duration of a brake cycle corresponding to said duration.
9. The power tool of claim 4, wherein the energy supply comprises an accumulator.
10. The power tool of claim 4, wherein the at least one operating-state variable is derived from a variable selected from the group consisting of a prevailing voltage of the motor, a current consumption of the motor, a charge state of the accumulator, a discharge state of the accumulator, a drive speed, a drive acceleration, an output drive speed, a drive acceleration, a drive torque, an output drive torque, an angle of rotation, a penetration depth, a machining depth, an exposure to oscillation, an exposure to vibration, a holding moment of the power tool, a moment of reaction of the power tool, a switch-on state, an operating mode of the power tool, and operating temperature of the power tool.
11. The power tool of claim 4, wherein said controller is configured for deriving the duration of said first time segment and consequently said duration of said second time segment from a duration of a previous commutation interval, so that maximum values for current or voltage are limited.
12. The power tool of claim 4, wherein said motor is configured as a permanently excited motor with electronic commutation.
13. The power tool of claim 12, wherein said motor has a permanently excited rotor which is linked to least one position transmitter for detecting an angular position of said rotor.
14. The power tool of claim 12, wherein said controller is configured for indirectly detecting an angular position of said rotor via a mutual induction of an exciting winding of said motor.
15. The power tool of claim 4, wherein said motor comprises a plurality of exciting windings, said exciting windings being configured in a star connection or in a delta connection.
16. The power tool of claim 4, wherein said controller during a brake cycle is configured to initiate a repeated cycling between said first time segment and said second time segment.
17. The power tool of claim 4, wherein said controller during a brake cycle is configured to initiate a repeated cycling between said first time segment, said second time segment and a free-running phase.
18. The power tool of claim 4, wherein said controller is configured for causing a pulse-width-modulated feeding of current during at least one of said first and second time segments.
19. The power tool of claim 4, wherein said controller is configured for causing a pulse-width-modulated short circuiting of said motor during at least one of said first and second time segments.
20. A method of decelerating a drive movement of a power tool having a motor, comprising the following steps:
detecting at least one operating-state variable of a power tool;
generating a brake signal as a function of the at least one operating-state variable;
initiating a braking procedure as a function of a brake signal, the braking procedure having at least one brake cycle comprising a first time segment and a second time segment;
wherein the motor is short-circuited during the first time segment; and
wherein current is fed into the motor opposite to an original direction of rotation during the second time segment.