Abstract An improved setting device for providing accurately reproducible, incrementally variable control voltages to the input of a control and regulating circuit for adjusting electromagnetic coil current in magnifying lenses of electron microscopes. The setting device includes a digital counter, preferably a forward-backward counter, connected to the input of the control circuit through a digital-to-analog converter. A digital-to-digital converter, programmed with a series of predetermined control settings, is connected between the output of the digital counter and the input to the digital-to-analgo converter to serve as a read-only memory for supplying a programmed magnification setting in response to address signals from the counter. A pulse source, preferably pushbuttoncontrolled, provides stepping pulses for adjusting the output voltage of the setting device to achieve desired values of magnification as indicated by a numeric display device connected to the output of the digital counter.
Inventors
👤 K Muller
👤 V Rindfleisch
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-29 05:30
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/24
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
137 words
An arrangement for adjusting the magnification of an electron microscope having electromagnetic lenses which influence the electron beam, the excitation current through said lenses being controlled by a control and regulating circuit with an input connected to the output of a setting device for supplying control voltages for adjusting the lens current, wherein the setting device comprises: a. a digital counter having an input and an output for supplying a digital signal equal to the count of stepping pulses fed to the input; b. a digital-to-digital converter acting as a read-only memory having an input connected to the output of the digital counter; and c. a digital-to-analog converter having an input connected to the output of the digital-to-digital converter and an output connected to the input of the control and regulating circuit for one of said lenses.
Claim 2
Dependent Claim
137 words
An arrangement for adjusting the magnification of an electron microscope having electromagnetic lenses which influence the electron beam, the excitation current through said lenses being controlled by a control and regulating circuit with an input connected to the output of a setting device for supplying control voltages for adjusting the lens current, wherein the setting device comprises: a. a digital counter having an input and an output for supplying a digital signal equal to the count of stepping pulses fed to the input; b. a digital-to-digital converter acting as a read-only memory having an input connected to the output of the digital counter; and c. a digital-to-analog converter having an input connected to the output of the digital-to-digital converter and an output connected to the input of the control and regulating circuit for one of said lenses.
Claim 3
Dependent Claim
13 words
The arrangement of claim 1 wherein the digital counter comprises a forward-backward counter.
Claim 4
Dependent Claim
22 words
The arrangement of claim 1 further comprising key-operated means for controlling the stepping pulses fed to the input of the digital counter.
Claim 5
Dependent Claim
14 words
The arrangement of claim 3 wherein the key means controls the stepping pulses one-by-one.
Claim 6
Dependent Claim
39 words
The arrangement of claim 1 further comprising: a. second digital-to-digital converter acting as a read-only memory and connected to the output of the digital counter; and b. an indicating device connected to the output of the second digital-to-digital converter.
Claim 7
Dependent Claim
17 words
The arrangement of claim 5 wherein the indicating device comprises numerals indicating the magnification or diffraction lengths.
Claim 8
Dependent Claim
55 words
The arrangement of claim 1 further comprising: a. at least one additional digital-to-digital converter acting as a read-only memory connected to the output of the digital counter; and b. a digital-to-analog converter connected between each additional digital-to-digital converter and the input to the control and regulating circuit for at least one other of said lenses.