Radiographic imaging apparatus and methods including stable power down

A method of operating a digital radiographic detector, the radiographic detector including an imaging array comprising a plurality of pixels arranged in rows and columns, each pixel comprising a thin-film photosensor configured to generate a signal based upon radiation received, the method comprising:

• operating the imaging array in a first mode, the first mode comprising,
• providing a first reference voltage using a first reference voltage line to a portion of the imaging array,
• commanding a multiplexer circuit to selectively couple selected pixels of the portion of the imaging array to enabling first control lines, and
• reading signals from the selected pixels of the portion of the imaging array using enabled second control lines;
• and
• operating the imaging array in a second mode, the second mode comprising,
• sequentially removing power of the first reference voltage, the multiplexer circuit for the first control lines, and the second control lines, where the power for the second control lines is removed before the power for the first reference voltage;
• and the power for the first reference voltage is removed before the power for the multiplexer circuit.

A digital radiographic area detector comprising:

• a housing configured to include an upper surface, a lower surface, and side surfaces to connect the upper surface and the lower surface;
• an insulating substrate inside the housing;
• an imaging device mounted inside the housing on the insulating substrate, the imaging device comprising a plurality of pixels, each pixel comprising at least one electrically chargeable photosensor and at least one thin-film transistor;
• a bias control circuit to provide a bias voltage to the photosensors for a portion of the imaging array;
• an address control circuit to control scan lines, where each of the scan lines is configured to extend in a first direction and is coupled to a plurality of pixels in the portion of the imaging array;
• and
• a signal sensing circuit connected to data lines, where each of the data lines is configured to extend in a second direction and is coupled to at least two pixels in the portion of the imaging array;
• the imaging device to operate in a first mode to detect radiation, the imaging device to operate in a second mode for power down operations of the imaging device by removing power from the bias control circuit, power from the address control circuit, and power from the signal sensing circuit,
• where in the second mode, the power of a first one of the bias control circuit, the address control circuit, and the signal sensing circuit is removed before the power of a second one of the bias control circuit, the address control circuit, and the signal sensing circuit, and then the power of the second one of the bias control circuit, the address control circuit, and the signal sensing circuit is removed before the power of the remaining one of the bias control circuit, the address control circuit, and the signal sensing circuit is removed.