Patent ID: 7049771

Claim:
A multi-phase carrier signal generator for generating multi-phase triangular wave carrier signals comprising: a clock generation means which generates a clock signal of predetermined frequency; and carrier signal generation sections for respective phases, each section generating a single triangular wave carrier signal, wherein each of the carrier signal generation sections comprises: a counting means which counts the number of clock signals generated by the clock generation means and subjects a count value to cumulative addition or cumulative subtraction, to thus output a triangular wave carrier signal; a first detection means which detects that a count value of the counting means has reached a predetermined upper limit value; a second detection means which detects that a count value of the counting means has reached a predetermined lower limit value; and a command means which issues to the counting method a subtraction command for effecting the cumulative subtraction on the basis of a detection output from the first detection means and which issues to the counting means an addition command for effecting cumulative addition on the basis of a detection output from the second detection means; and the counting means of one phase outputs a triangular wave carrier signal having a predetermined phase difference from a triangular wave carrier signal output from the counting means of another phase.