X-ray imaging apparatus
AssigneeShimadzu Corporation
InventorHiroshi Okumura
Life of this patent
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Abstract
Provided is an X-ray imaging apparatus equipped with an LED driver circuit capable of properly and safely lighting an LED lamp even when an LED driver circuit is connected to any one of a plurality of internal power supplies different in voltage in the case of using an LED lamp as a collimator lamp. The LED driver circuit is provided with a rectifier circuit, a smoothing circuit, an input voltage level detector, a power connection switching unit for switching a change-over switch, and a DC-DC converter circuit. The DC-DC converter circuit is composed of a current control type DC chopper circuit and configured to measure the current from the voltage of both ends of a resistor and perform ON/OFF control of a transistor on the basis of the current to thereby function as a step-up/down chopper circuit or step-down chopper circuit.
Claims9
An X-ray imaging apparatus comprising:
- an X-ray tube;
- an X-ray detector configured to detect an X-ray irradiated from the X-ray tube and passed through a subject;
- a collimator equipped with a plurality of collimator leaves for changing an X-ray radiation field irradiated from the X-ray tube toward the subject and a collimator lamp for making the X-ray radiation field to be adjusted by the collimator leaves visible, wherein the collimator lamp comprises an LED lamp;
- and
- a plurality of types of internal power supplies different in voltage from each other;
- and
- an LED driver circuit connected to the LED lamp, the LED driver circuit is configured to connect to each of the internal power supplies and configured to convert a voltage of each of the internal power supplies as a connected internal power supply to a forward voltage of the LED lamp to thereby light the LED lamp.
Dependencies are inferred from the claim text.