Abstract: A frequency calibration (FCAL) circuit and a method for calibrating an oscillation frequency of a controllable oscillator are provided. The FCAL circuit includes the controllable oscillator, a divider, a time-to-digital converter (TDC) and a calibration logic. The controllable oscillator generates a controllable oscillation clock according to a calibration code. The divider divides the oscillation frequency of the controllable oscillation clock by a predetermined divisor to generate a divided clock. The TDC converts a first period between first edges of a reference clock and the divided clock into a first period code and converts a second period between second edges of the reference clock and the divided clock into a second period code. The calibration logic compares the first period code and the second period code to generate a comparison result for determining whether the first period is greater or less than the second period, and accordingly controls the calibration code.

Abstract: An optical system affixed to an electronic apparatus is provided, including a first optical module, a second optical module, and a third optical module. The first optical module is configured to adjust the moving direction of a first light from a first moving direction to a second moving direction, wherein the first moving direction is not parallel to the second moving direction. The second optical module is configured to receive the first light moving in the second moving direction. The first light reaches the third optical module via the first optical module and the second optical module in sequence. The third optical module includes a first photoelectric converter configured to transform the first light into a first image signal.

Abstract: A cell mechanical stimulating device for applying to at least one cell sample is provided. The device includes a base unit, at least one moving component and at least one magnetic component. The base unit includes a base body and a separating lid. The base body includes at least one culturing chamber and a bottom chamber surface. The cell sample is disposed in the culturing chamber, and the separating lid encloses the culturing chamber. The magnetic component drives the moving component to shift between a pressurizing position and a non-pressurizing position. At the pressurizing position, the moving component moves toward the bottom chamber surface and pressurizes the cell sample. At the non-pressurizing position, the moving component moves toward the separating lid and the pressure on the cell sample is removed. The cell sample is pressurized by the magnetic component driving the moving component.