A recording apparatus with a recording unit for recording an image on a recording medium in consonance with an image signal, a feeder for feeding the recording medium to the recording unit, first auxiliary feeding unit, which contact the feeder when the recording medium is cut sheet paper, but which is separated from the feeder when the recording medium is continuous sheet paper in order to form a feeding route for the continuous sheet paper, second auxiliary feeding unit, which contacts the feeder when the recording medium is cut sheet paper, but which maintains a contact position with the feeder which decreasing pressure against the feeder when the recording medium is continuous sheet paper, and third auxiliary feeding unit, which contacts the feeder when the recording medium is cut sheet paper, but which decreases pressure against the feeder when the recording medium is continuous sheet paper, and switching device for selecting the forward or the backward movement of the first and the second auxiliary feeding unit to the feeder, whereby the sliding center of the first auxiliary feeding unit with respect to the feeder.
A power connection/disconnection mechanism which connects and disconnects power, including: a crutch cover having a claw portion, and a projection which a contact portion of a lever is brought into abutment with; a gear having a toothed portion which the claw portion is brought into engagement with and disengagement from, wherein a mesh engagement portion formed from the claw portion and the toothed portion has two stages for forward and backward rotations.
Sidelobe levels of bipolar and unipolar waveforms are suppressed. Bipolar and unipolar transmit waveforms are generated with a coded excitation, such as a chirp coding, and pulse width modulation. For harmonic, such as second harmonic, imaging, the fundamental transmit frequency of the transmit waveform is centered at a lower end of the bandwidth of the transducer. The transducer filters higher frequency components of the transmit waveform differently than lower frequency components. To generate the desired acoustic waveform, the transmit waveform generated for application to the transducer is adjusted to account for the frequency response of the transducer. For example, higher frequency parts of a chirp waveform has more pulse width modulation or narrower pulse widths to account for lesser magnitude reductions. Multiple transmit waveforms may be combined to reduce sidelobes for fundamental or second harmonic imaging. Two coded excitation waveforms are generated. One waveform is delayed relative to the other waveform, such as applying a 90.degree. phase difference or .pi. ##EQU00001## delay of one waveform relative to the other waveform. The coded excitation waveforms are then combined. For example, the two waveforms are summed for application to a transducer element. As an alternative example, the waveforms are transmitted from different elements of the transducer array and sum in the acoustic domain.
