Abstract: The invention relates to a method for determining a set-point voltage for a piezoelectric actuator system to achieve a desired optical response of the piezoelectric actuator system, such as an optical power. The method is based on a mathematical model, OP(V,T,n) describing a relationship between the applied voltage and the optical response. Calibration and use of the model involves determining a transition time count value. During use, e.g. at given intervals, the model is updated based on actual values of the temperature and the transition time count value. The set-point voltage required to achieve a desired optical response is determined based on the updated model and the set-point voltage is applied to the piezoelectric actuator.

Abstract: A MEMS optical device including: a semiconductor body; a main cavity, which extends within the semiconductor body; a membrane suspended over the main cavity; a piezoelectric actuator, which is mechanically coupled to the membrane and can be electronically controlled so as to deform the membrane; a micro-lens, mechanically coupled to the membrane so as to undergo deformation following the deformation of the membrane; and a rigid optical element, which contacts the micro-lens and is arranged so that the micro-lens is interposed between the rigid optical element and the membrane. The micro-lens and the main cavity are arranged on opposite sides of the membrane.

Abstract: The invention relates to an optical assembly for use with compact camera modules. The optical assembly comprises a transparent optical element, an optical reflection surface arranged to deflect a light through the optical element, a transparent elastic non-fluid body and an actuator system comprising one or more actuators and an actuator-component arranged to undergo bending and/or displacement by the one or more actuators. The non-fluid body may be sandwiched between the actuator-component and the optical element so that the shape or orientation of the actuator component and the non-fluid body can be changed by actuation of the actuators to provide adjustable optical power or beam deflection.

Abstract: A MEMS optical device including: a semiconductor body; a main cavity, which extends within the semiconductor body; a membrane suspended over the main cavity; a piezoelectric actuator, which is mechanically coupled to the membrane and can be electronically controlled so as to deform the membrane; a micro-lens, mechanically coupled to the membrane so as to undergo deformation following the deformation of the membrane; and a rigid optical element, which contacts the micro-lens and is arranged so that the micro-lens is interposed between the rigid optical element and the membrane. The micro-lens and the main cavity are arranged on opposite sides of the membrane.

Abstract: The invention relates to a method and an actuator system for determining and applying a voltage to a piezoelectric actuator (PEA) to achieve a given setpoint displacement. The method involves determining a relation dcal(V) between a PEA displacement measure (d) and voltage (V) and a relation ttcal(V) between transition time (tt) and voltage and combining the determined relations to calculate a relation d(tt) between the displacement measure and transition time during an initial calibration procedure. This relation is characteristic for the PEA, and by determining a new relation ttnew(V) after repeated biasing of the PEA, a compensated relation dc(V) can be calculated by substituting ttnew(V) in the calculated d(tt). The compensated relation dc(V) compensates for piezo creep effects due to the wear and can be used to determine the voltage to be applied directly, or be used in other compensation algorithms.

Abstract: The invention relates to a tunable lens where the optical power can be adjusted. The lens consists of a deformable, non-fluid lens body sandwiched between a thin, flexible membrane and transparent back window, and an actuator system serving to change the overall shape of the membrane and lens body. The membrane is pre-shaped to have a Sag or Sagittal of at least 10 ?m so that the lens has a non-zero optical power when the actuator system is not activated. In order to achieve a large optical power range for the lens, the membrane should preferably be made of a material having a Young's modulus in the range 2-1.000 MPa.

Abstract: There is presented an optical element 100, such as a tuneable lens, wherein there is provided means 128 to mitigate problems with stress concentration in a bendable cover member 102 at a border of a supporting structure 101, which in the absence of said means would entail a stress singularity issue due to an abrupt change in mechanical properties around the bendable cover member 102.

Abstract: The invention relates to an adjustable or tuneable lens assembly where a deformable, non-fluid lens body is sandwiched between a bendable lens cover and a back window to form a lens. The lens assembly has an actuator system with a plurality of individually addressable actuators for applying force to the lens cover in direction along the optical axis to change an overall shape of the lens. The actuator system has a focus adjustment mode to adjust the optical power of the lens and an optical image stabilisation mode, which are configured to operate simultaneously by addressing each actuator to apply a force being at least substantially a sum of the forces that would be applied in these modes.

Abstract: There is presented an optical element (100, 500, 600, 700) comprising a support structure (101, 501) with a sidewall (112, 512), a bendable cover member (102, 502, 702) attached to the sidewall (112, 512), one or more piezoelectric actuators (103, 104, 105) arranged for shaping said bendable cover member (102, 502, 702) into a desired shape, wherein said optical element (100, 500, 600, 700) comprises an optically active area (111, 511) with an optical axis (110, 510), wherein an outer edge (215A-E) of the one or more piezoelectric actuators (103, 104, 105) as observed in a direction being parallel with the optical axis (110, 510) defines a first line, and an inner edge (109) of the support structure (101, 501) at the interface between the support structure (101, 501) and the bendable cover member (102, 502, 702) as observed in the direction being parallel with the optical axis (110, 510) defines a second line, wherein the first line and the second line as observed in the direction being parallel with the opti

Abstract: The invention relates to an electronic circuit (100) for controlling charging of a piezoelectric load (190). The electronic circuit comprises a charge pump (111) configured to supply a charging current to the piezoelectric load dependent on a charge control signal (131), a measurement circuit (113) configured to obtain a load voltage corresponding to a terminal voltage at a load terminal of the piezoelectric load, a comparator circuit (114) configured to compare an adjustable reference voltage with the load voltage. The electronic circuit is configured to determine the charge control signal dependent on the comparison so that the control signal controls delivery of the charging current dependent on the comparison. The electronic circuit is further configured to set the adjustable reference voltage to a target voltage (VT) and to set the adjustable reference voltage to a low limit voltage (Vlow), being lower than the target voltage, when the load voltage reaches the target voltage.

Abstract: The present invention relates to a transparent optical device element comprising a microlens and a method of providing stress and thermal compensation and tuning mechanical strength and curvature of a tunable microlens.

Abstract: The present invention relates to transparent optical device elements comprising a deformable lens body and to a method for changing the refractive index (RI) of a deformable lens body. The deformable lens body of the invention has an improved mechanical stability, a high refractive index, an optimal degree of stiffness and sheer modulus for use as optical lens.