Microscope system and microscope focus maintaining device for the same

Abstract

A microscope system has a stage on which an observation sample, including an observation object and a transparent member, is to be placed. An objective lens is placed to face the observation sample placed on the stage, and a focusing unit moves at least one of the stage and the objective lens to perform a focusing operation. An autofocus unit controls a focusing driving unit by a so-called Through-the-Lens: TTL system. After autofocus is performed for the transparent member by the autofocus unit, the focusing driving unit makes at least one of the stage and the objective lens move by a predetermined constant amount.

1 . A microscope system comprising:
 a stage which is adapted to have an observation sample, including an observation object and a transparent member, placed thereon;   an objective lens which is positioned to face the observation sample placed on the stage;   a focusing driving unit which moves at least one of the stage and the objective lens to perform a focusing operation; and   an autofocus unit which controls the focusing driving unit by a Through-the-Lens system;   wherein after autofocusing is performed for the transparent member by the autofocus unit, the focusing driving unit performs offset driving to move at least one of the stage and the objective lens by a predetermined offset amount;   wherein the offset amount is a difference between: (i) a distance between the stage and the objective lens upon completion of autofocusing and (ii) a distance between the stage and the objective lens upon completion of a focus adjustment, which is set in advance by performing autofocus for the transparent member and focus adjustment for the observation object; and   wherein the autofocusing is performed in a same direction as a direction of the offset driving, regardless of a positional relationship between a starting position of the autofocus and a focus position for the transparent member with respect to each other.   
   
   
       2 . A microscope system according to  claim 1 , further comprising:
 an X-Y stage driving unit which drives and controls the stage in a direction perpendicular to an observation optical axis, and which is adapted to register, in advance, a stage address set at a plurality of measuring points at X-Y positions, the offset amount being set for each stage address of each of the plurality of measuring points registered by the X-Y stage driving unit.   
   
   
       3 . A microscope system according to  claim 1 , further comprising:
 an objective lens switching unit which holds a plurality of objective lenses, and which selectively switches one of the plurality of objective lenses on the optical path;   wherein the offset amount is set in advance for each of the plurality of objective lenses, and   wherein the autofocus unit performs the offset driving in accordance with the offset amount corresponding to the objective lens arranged on the optical path.   
   
   
       4 . A microscope system according to  claim 1 , further comprising:
 an illumination optical system for fluorescence observation which selectively applies excitation light with different wavelengths to the observation object;   wherein the offset amount is set in advance for each excitation light, and   wherein the autofocus unit performs the offset driving in accordance with the offset amount corresponding to excitation light of a wavelength selected from the different wavelengths.   
   
   
       5 . A microscope system according to  claim 1 ,
 wherein a photographing area in a driving direction of the focusing driving unit is set based on a focus position for the observation object upon the offset driving, and   wherein the autofocus unit performs photographing from an upper limit position to a lower limit position of the set photographing area at each time interval while driving the focusing driving unit.   
   
   
       6 . A microscope system according to  claim 5 ,
 wherein the photographing area is set in accordance with a pitch of Z-movement of the stage and a number of photographing operations to be carried out.   
   
   
       7 . A microscope system according to  claim 5 ,
 wherein the photographing area is set in accordance with a range of movement in the Z-direction from the upper limit position to the lower limit position of the stage and a number of photographing operations to be carried out.   
   
   
       8 . A microscope system comprising:
 a stage which is adapted to have an observation sample, including an observation object and a transparent member, placed thereon;   an objective lens which is positioned to face the observation sample placed on the stage;   a focusing unit which moves at least one of the stage and the objective lens to perform a focusing operation; and   an autofocus unit which controls the focusing driving unit by a Through-the-Lens system;   wherein after autofocusing is performed for the transparent member by the autofocus unit, the focusing driving unit performs offset driving to move at least one of the stage and the objective lens by a predetermined offset amount;   wherein the offset amount is a difference between: (i) a distance between the stage and the objective lens upon completion of autofocusing and (ii) a distance between the stage and the objective lens upon completion of a focus adjustment, which is set in advance by performing autofocus for the transparent member and focus adjustment for the observation object;   wherein a photographing area in a Z-direction is set based on a focus position for the observation object upon the offset driving; and   wherein photographing is performed from an upper limit position to a lower limit position of the set photographing area at each time interval by further moving at least one of the stage and the objective lens in the Z-direction from a basic position after the offset driving.   
   
   
       9 . A microscope system according to  claim 8 ,
 wherein the photographing area is set in accordance with a pitch of Z-movement of the stage and a number of photographing operations to be carried out.   
   
   
       10 . A microscope system according to  claim 8 ,
 wherein the photographing area is set in accordance with a range of movement in the Z-direction from the upper limit position to the lower limit position of the stage and a number of photographing operations to be carried out.