Abstract: An encoding and decoding apparatus quantizes LSP (Line Spectrum Pair) parameters, which are characteristics parameters of spectrum information included in a voice signal, with high accuracy and stability. This encoding and decoding apparatus comprises a first quantizer in which quantization is performed independently in the unit of one frame, and a second quantizer which uses a correlation between adjacent frames. An error comparator compares quantization errors produced by the first quantizer and quantization errors produced by the second quantizer to select the one quantizer whose quantization errors are less than that of the other quantizer. The first quantizer produces a highly accurate quantization with stability regardless a condition of an input voice signal, while the second quantizer produces a highly accurate quantization when input voice signal stays quasi-stationary.

Abstract: A predicted residual signal is calculated from a current input speech signal and a past input speech signal, and a cross-correlation between the predicted residual signal and the past input speech signal having one speech sub-frame length stored in a first code book is calculated. In cases where the current input speech signal has no local peak, the cross-correlation becomes high, so that a synthesized speech signal is generated from the past input speech signal stored in the first code book or a predetermined sound source signal having one speech sub-frame length stored in the second code book. In contrast, in cases where the current input speech signal has a local peak, the cross-correlation becomes low, so that it is judged that a function of the first code book is depressed. In this case, a synthesized speech signal is generated from a group of short-length sound source signals having a total length equal to one speech sub-frame length stored in a short-length signal code book.

Abstract: A sheet carrying apparatus reduces skew of a sheet during carriage, and realizes high-quality print. A position detecting sensor detects a position in a direction perpendicular to a sheet carrying direction of the sheet carried by a sheet carrying roller. A skew angle of the sheet is calculated depending upon a deviation of the detected position from a predetermined reference position. Load rollers are on the right and left sides with respect to a sheet center line in the sheet carrying direction, and are respectively opposed to following rollers through the sheet so as to bring the sheet into pressure contact. A torque limiter to apply a braking force to the load roller, and the load roller are coupled or released by electromagnetic clutches. Thereby, the carrying forces can independently be controlled on the right and left sides of the sheet depending upon the skew angle.

Abstract: A sheet carrying apparatus reduces skew of a sheet during carriage, and realizes high-quality print. A position detecting sensor detects a position in a direction perpendicular to a sheet carrying direction of the sheet carried by a sheet carrying roller. A skew angle of the sheet is calculated depending upon a deviation of the detected position from a predetermined reference position. Load rollers are on the right and left sides with respect to a sheet center line in the sheet carrying direction, and are respectively opposed to following rollers through the sheet so as to bring the sheet into pressure contact. A torque limiter to apply a braking force to the load roller, and the load roller are coupled or released by electromagnetic clutches. Thereby, the carrying forces can independently be controlled on the right and left sides of the sheet depending upon the skew angle.

Abstract: A sheet feeding apparatus detects the position of a sheet (30) during feeding thereof and calculates a deviation of the detected sheet position relative to a reference position to thereby enable accurate color printing. A follower roller (41) for detecting a feeding amount of the sheet is in contact with the sheet which is fed by a sheet feeding roller 1, so that is rotated in accordance with the movement of the sheet. A sensor (43) generates an output signal each time the follower roller (41) rotates a predetermined angle of rotation. In one form of the invention, a timing deviation detector (51) is provided for detecting a deviation in the output timing of an output signal of the sensor relative to a reference value. In another form, a rotation angle deviation detector is provided for detecting a deviation in the rotation angle of the sheet feeding roller relative to a reference value each time the sensor generates an output signal.