Abstract: In order to appropriately set MSm analysis conditions, an MSm-1 analysis executer (51) makes a mass spectrometer (20) perform an MSm-1 analysis (where m is an integer from 2 to n) to acquire three-dimensional data showing an intensity for each of the N m/z values and each of the M retention times (where N and M are natural numbers). Based on the three-dimensional data, a data matrix creator (41) creates data matrix X in which intensity data are arranged in N rows which differ from each other in m/z value and M columns which differ from each other in retention-time value. A matrix factorization executer (42) determines an N×K spectrum matrix S and K×M profile matrix P (where K is a natural number) by matrix factorization based on data matrix X so that this matrix X is approximated by product SP of the matrices S and P. An m/z detector (43) detects m/z of a precursor ion originating from a sample component from the values of the matrix elements in each column of matrix S.

Abstract: Herein disclosed is a carriage driving mechanism for use with a floppy disc drive or the like to drive a carriage carrying a magnetic head so that the magnetic head may be driven to a desired track on the floppy disc to record or read out data in or from a floppy disc. The carriage driving mechanism comprises: a drive shaft having a helical guide groove in its outer circumference; a prime mover for turning the drive shaft; a guide shaft extending in parallel with the drive shaft; a carriage mounted slidably on the guide shaft; and a follower carried on the carriage and engaging with the guide groove of the drive shaft. A spring member is carried on the carriage to mount the follower thereon so that the follower may have its tip guided elastically by the guide groove of the drive shaft.