Z positioning of objectives with PIFOC
A positioning of the sample in the Z direction, i.e. along the optical axis of the objective, is required in many examinations or for microscopy technologies. Alternatively, it is possible to move the objective itself in the Z direction. For this purpose, PI offers solutions named PIFOC.
Integrated weight force compensation
The product is equipped with a magnetic weight force compensation. This maintains the position of a load of up to 1 kg aligned vertically to the motion axis even if no power is applied. The weight force compensation can be adjusted by the user.
PIMag® voice coil motor
Voice coil motors are direct drives. In direct drives, the force of the drive element is transmitted directly to the load to be moved without the use of mechanical transmission elements such as coupling, drive screw, or gearhead. Voice coil drives consist of a permanent magnet and a winding body that are located in the air gap of the magnetic field. When current flows through the winding body, it moves in the magnetic field of the permanent magnet. Thanks to their low weight and friction-free drive principle, voice coil drives are particularly suitable for applications that require high dynamics and high velocities at limited travel ranges. High scan frequencies and precision positioning are also possible with these drives, because they are free of the effects of hysteresis.
Crossed roller guide
With crossed roller guides, the point contact of the balls in ball guides is replaced by line contact of the hardened rollers. Consequently, they are considerably stiffer and need less preload, which reduces friction and allows smoother running. Crossed roller guides are also distinguished by high guiding accuracy and load capacity. Force-guided rolling element cages prevent cage creep.
Direct position measuring
Position measuring is performed with the highest accuracy directly at the motion platform so that nonlinearity, mechanical play, or elastic deformation have no influence on position measuring.
Application fields
Microscopy: Multiphoton fluorescence microscopy, deep tissue inspection, digital slide scanning microscopy. Biotechnology: Genome sequencing with the Solexa-Illumina method, Immuno-Assay fluorescence. Medical devices: Scanning laser ophthalmology, automated cell counters/flow cytometers. Biomedical research: Optical & magnetic tweezers. Laser materials processing: Laser micromachining, laser ablation. Semiconductor industry: Semiconductor/wafer inspection.
| Motion | V-308.753030 | Tolerance |
|---|---|---|
| Active axes | Z | |
| Travel range in Z | 7 mm | |
| Acceleration in Z, unloaded | 8 m/s² | max. |
| Maximum velocity in Z, unloaded | 200 mm/s | |
| Straightness error E_XZ | ± 0.75 µm | max. |
| Straightness error E_YZ | ± 0.75 µm | max. |
| Angular error E_AZ | ± 50 µrad | max. |
| Angular error E_BZ | ± 50 µrad | max. |
| Angular error E_CZ | ± 50 µrad | max. |
| Positioning | V-308.753030 | Tolerance |
| Minimum incremental motion in Z | 0.01 µm | typ. |
| Positioning accuracy in Z, calibrated | ± 0.6 µm | typ. |
| Positioning accuracy in Z, uncalibrated | ± 4 µm | typ. |
| Bidirectional repeatability in Z | 1 µm | typ. |
| Bidirectional repeatability in Z, 100 nm step | 50 nm | |
| Reference switch | Optical, direction sensing (reference edge track), 5 V, TTL | |
| Reference switch repeatability | 0.5 µm | |
| Integrated sensor | PIOne: Incremental linear encoder | |
| Sensor signal | Sin/cos, 1 V peak-peak | |
| Sensor signal period | 2 µm | |
| System resolution in Z | 1 nm | |
| Sensor resolution | 1 nm | |
| Position noise in Z | 3 nm | max. |
| Settling time in Z (100 nm step, ± 15 nm error band) | 15 ms | |
| Settling time in Z (250 nm step, ± 15 nm error band) | 15 ms | |
| Drive Properties | V-308.753030 | Tolerance |
| Drive type | Voice coil | |
| Nominal voltage | 48 V | |
| Nominal current, RMS | 1.15 A | typ. |
| Peak current, RMS | 3.5 A | typ. |
| Drive force in positive direction of motion in Z | 4.2 N | typ. |
| Drive force in negative direction of motion in Z | 4.2 N | typ. |
| Peak force in positive direction of motion in Z | 9.45 N | |
| Peak force in negative direction of motion in Z | 9.45 N | |
| Force constant | 2.7 N/A | |
| Motor constant | 1.37 N/√W | typ. |
| Resistance phase-phase | 3.9 Ω | typ. |
| Inductance phase-phase | 0.85 mH | |
| Back EMF | 2.7 V·s/m | max. |
| Permissible maximum temperature for drive components | 50 °C | |
| Mechanical Properties | V-308.753030 | Tolerance |
| Permissible push force in X | 10 N | max. |
| Permissible push force in Y | 10 N | max. |
| Permissible push force in Z | 10 N | max. |
| Moved mass in Z, unloaded | 200 g | |
| Guide | Crossed roller guide | |
| Overall mass | 600 g | |
| Mass without cable | 450 g | |
| Material | Aluminum, anodized | |
| Miscellaneous | V-308.753030 | Tolerance |
| Operating temperature range | 10 to 50 °C | |
| Connector | HD D-sub 26 (m) | |
| Cable length | 1.5 m | |
| Recommended controllers / drivers | C-414, G-910, ACS SPiiPlus + NPMpm (NanoPWM incl.) |
Note on sensor resolution and minimum incremental motion: With C-414 motion controller at an interpolation of 211
Note on settling time: With gain scheduling (only with NanoPWM)
Note on positioning accuracy and repeatability: Following ISO 230-2
Note on nominal current, peak current: Max. 10 s at 70 °C coil temperature
Note on nominal current, RMS: Value without cooling; with cooling: 1.55 A; with horizontally aligned positioner, with perforated plate made of steel, 200 mm × 250 mm × 12 mm
Note on inductance: Value at 100 mHz
At PI, technical data is specified at 22 ±3 °C. Unless otherwise stated, the values are for unloaded conditions. Some properties are interdependent. The designation "typ." indicates a statistical average for a property; it does not indicate a guaranteed value for every product supplied. During the final inspection of a product, only selected properties are analyzed, not all. Please note that some product characteristics may deteriorate with increasing operating time.
For V-308.753030 Voice coil PIFOC high dynamics focus drive
V-308.753030 Voice coil PIFOC high dynamics focus drive
High Dynamics objective focus drive with weight force compensation
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Voice coil PIFOC focus drive for objectives; voice coil; 7 mm travel range; 10 N load capacity; 200 mm/s max. velocity; PIOne: incremental linear encoder, 2 µm sensor signal period, sin/cos, 1 V peak-peak; 1.5 m cable length
