Abstract: A microscope including an imaging optical unit, a sample stage for supporting a sample to be examined, a movement unit, by which the distance between sample stage and imaging optical unit can be altered, a focus measuring unit, which measures the present focus position and outputs a focus measurement signal, a control unit for maintaining a predetermined focus position for examinations of the sample that are separated from one another in time. The control unit receives the focus measurement signal and derives a deviation of the present focus position from the predetermined focus position. Dependent on the deviation derived the movement unit, changes the distance between sample stage and imaging optical unit so that the predetermined focus position is maintained. The control unit drives the movement unit (9) for maintaining the predetermined focus position only before and/or after at least one of the examinations, but never during the examinations.

Abstract: An apparatus for transmitted light illumination for light microscopes A diaphragm edge may be variably positioned in the direction of the optical axis, wherein a position of the diaphragm edge in the direction of the optical axis can be varied irrespectively of a position of the diaphragm edge transversely to the optical axis. A separate sample support table may be mounted on a housing. The housing has a passage opening, through which the diaphragm edge can be moved in the direction of the optical axis. A holding device is formed in the region of the passage opening of the housing or on a separate sample support table and a control device is present which is adapted to position the diaphragm edge in dependence at least upon a determined presence of a sample support table.

Abstract: The invention relates to an apparatus for transmitted light illumination for light microscopes, in particular stereo microscopes or macroscopes, having changing effective entrance pupil of an objective. The apparatus has a light source for emitting an illuminating light beam, a housing, in which the light source is arranged, a holding device for holding a sample to be examined and at least one diaphragm edge for trimming the illuminating light beam, wherein the diaphragm edge extends transversely to an optical axis of a light microscope, which can be positioned in an operating state on the device for transmitted light illumination, and wherein a beam path of the illuminating light between the diaphragm edge and the sample held by the holding device is free from adjustable beam focussing components.

Abstract: The invention relates to a microscope having a stage for supporting a sample to be examined, a recording sensor, an imaging optic for imaging the sample onto the recording sensor, a moving unit by means of which the distance between the stage and the imaging optic can be changed, a control unit for controlling an image recording of the sample and a focus-holding unit for maintaining a prescribed focal position for image recording of the sample at temporal intervals, wherein the focus-holding device comprises at least one hardware element and one software module, wherein the focus-holding unit is fully integrated in the control unit, on both the hardware and software sides.

Abstract: A microscope including an imaging optical unit, a sample stage for supporting a sample to be examined, a movement unit, by which the distance between sample stage and imaging optical unit can be altered, a focus measuring unit, which measures the present focus position and outputs a focus measurement signal, a control unit for maintaining a predetermined focus position for examinations of the sample that are separated from one another in time. The control unit receives the focus measurement signal and derives a deviation of the present focus position from the predetermined focus position. Dependent on the deviation derived the movement unit, changes the distance between sample stage and imaging optical unit so that the predetermined focus position is maintained. The control unit drives the movement unit (9) for maintaining the predetermined focus position only before and/or after at least one of the examinations, but never during the examinations.

Abstract: The invention relates to a microscope having a stage for supporting a sample to be examined, a recording sensor, an imaging optic for imaging the sample onto the recording sensor, a moving unit by means of which the distance between the stage and the imaging optic can be changed, a control unit for controlling an image recording of the sample and a focus-holding unit for maintaining a prescribed focal position for image recording of the sample at temporal intervals, wherein the focus-holding device comprises at least one hardware element and one software module, wherein the focus-holding unit is fully integrated in the control unit, on both the hardware and software sides.