US 4,544,885 AGranted

Cathode ray oscilloscope with a dual control knob assembly for easy zero level adjustment

AssigneeIwatsu Electric Co., Ltd.

InventorToru Takahashi

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Abstract

A cathode ray oscilloscope having a vertical or signal amplifier connected between a signal input terminal and a cathode ray tube for amplifying an input signal to be observed or measured. Upon disconnection of the vertical amplifier from the input terminal the cathode ray tube exhibits on its screen a bright horizontal line representative of a zero signal level. For the easy adjustment or setting of this zero signal level there is provided a one-hand-operable dual control knob assembly typically in the form of a concentric arrangement of first and second knobs. The first knob is to be pushed for activating a zero level switch, thereby to disconnect the vertical amplifier from the signal input. Sleeved upon the first knob, the second knob is to be turned for operating a potentiometric vertical position adjuster thereby to cause the bright line to move up and down on the cathode ray tube screen. The manipulation of only the first knob results in the appearance of the bright line on the screen, thus making possible the ready reconfirmation of the zero signal level.

Claims7

Dependent claims

A cathode ray oscilloscope of the kind having input means for the reception of a signal to be observed or measured, a vertical amplifier for amplifying the input signal, a cathode ray tube for displaying on a screen the amplified replica of the input signal, the cathode ray tube exhibiting on the screen a bright horizontal line representative of a zero signal level upon disconnection of the vertical amplifier from the input means, and a vertical position adjuster coupled to the vertical amplifier and operable manually for adjustably varying the vertical position of the display on the screen of the cathode ray tube, wherein the improvement comprises:

(a) a zero level switch connected between the input means and the vertical amplifier and actuable manually for connecting and disconnecting the input means and the vertical amplifier to and from each other;
and
(b) a one-hand-operable dual control knob assembly for operating the vertical position adjuster and actuating the zero level switch;
(c) whereby the zero signal level on the screen of the cathode ray tube is adjustable by the simple manipulation of the dual control knob assembly.

1 more element

Dependencies are inferred from the claim text.