The 3 main categories of readout microscopes
According to the different principles of subdivision, reading microscope is usually divided into direct reading type, line moving type and image moving type 3 kinds.
Direct-reading reading microscope: the scale on the line ruler by the objective lens local magnification image on the subdivision board, such as line spacing for 1 mm, magnified to the distance from the subdivision board with 100 degrees equal, through the eyepiece (magnification) can be read out 0.01 mm of the index value.
Scale line moving reading microscope: when measuring, turn the micro hand wheel, so that the movable dividing plate on the double engraved line and the line grain ruler line grain image alignment, from the reading drum wheel or other reading mechanism to read out the per centile and thousandths, from the movable dividing plate to read out the tenths. In order to avoid micro hand wheel on the precision threads (or other micro mechanism) wear, some microscopes on the movable demarcation plate of the double engraved line made of double Archimedes spiral. Double Archimedes spiral pitch is equal to 1/10 line ruler line spacing multiplied by the magnification of the objective lens, and in its inner circle and engraved with 100 equal divisions, so after it aligned with the line image, can be read from the fixed dividing board on the tenths of the number, from the movable dividing board on the per centile and the number of thousandths of the number of readings.
Image-moving reading microscope: between the objective lens and the dividing plate, a movable optical element is added (e.g., plane-parallel glass, light wedge glass, or compensating lens, etc.). When moving such optical components, the line grain ruler of the line grain image will move, the line grain image and the fixed dividing board on the double engraved line alignment, respectively, can be read from the fixed dividing board and movable dividing board on the tenths and per cent, thousandths of the value.
