Disclosed is a sewing machine which evaluates sewing quality using a stitch tightness index. During sewing operation, a used length of an upper thread per stitch is detected, and a stitch tightness index per sewn stitch is calculated on the basis of a stitch length per stitch defined by sewing pattern data, a fabric thickness of a sewing workpiece, and detected data of the used length of the upper thread. Then, notification is made which corresponds to the calculated stitch tightness index per sewn stitch (such as a visual display of the stitch tightness index). After that, acceptability/non-acceptability of the thread tightness per sewn stitch can be determined by comparing the calculated stitch tightness index per sewn stitch against a reference value, and a result of the determination can be notified.

Disclosed is a sewing machine which evaluates sewing quality using a stitch tightness index. During sewing operation, a used length of an upper thread per stitch is detected, and a stitch tightness index per sewn stitch is calculated on the basis of a stitch length per stitch defined by sewing pattern data, a fabric thickness of a sewing workpiece, and detected data of the used length of the upper thread. Then, notification is made which corresponds to the calculated stitch tightness index per sewn stitch (such as a visual display of the stitch tightness index). After that, acceptability/non-acceptability of the thread tightness per sewn stitch can be determined by comparing the calculated stitch tightness index per sewn stitch against a reference value, and a result of the determination can be notified.

A sewing machine includes at least one needle bar, a threading motor, a threading mechanism, a processor, and a memory. The threading mechanism is configured to pass an upper thread through an eye of a sewing needle. The memory is configured to store computer-readable instructions that, when executed by the processor, instruct the processor to perform processes. The processes include making one of a setting that prohibits operation of the threading mechanism and a setting that does not prohibit the operation of the threading mechanism. The processes include switching the operation of the threading mechanism by prohibiting the operation of the threading mechanism in a case where the setting that prohibits the operation of the threading mechanism is made, and permitting the operation of the threading mechanism in a case where the setting that does not prohibit the operation of the threading mechanism is made.

A sewing machine includes at least one needle bar, a threading motor, a threading mechanism, a processor, and a memory. The threading mechanism is configured to pass an upper thread through an eye of a sewing needle. The memory is configured to store computer-readable instructions that, when executed by the processor, instruct the processor to perform processes. The processes include making one of a setting that prohibits operation of the threading mechanism and a setting that does not prohibit the operation of the threading mechanism. The processes include switching the operation of the threading mechanism by prohibiting the operation of the threading mechanism in a case where the setting that prohibits the operation of the threading mechanism is made, and permitting the operation of the threading mechanism in a case where the setting that does not prohibit the operation of the threading mechanism is made.

A method for calibrating one or more optical sensors on a sewing machine, including collecting data of one or more features of one or more predefined regions associated with the sewing machine, processing the data through one or more neural networks, wherein the one or more neural networks detect and recognize the one or more features of the one or more predetermined regions from the data, calculating one or more accuracy indicators of the one or more features from the data as compared to one or more trained features from the one or more neural networks, comparing the value of the one or more accuracy indicators to one or more indicator thresholds and adjusting one or more parameters of one or more optical sensors based on the comparison between the one or more accuracy indicators and the one or more indicator thresholds.

The present invention provides a sewing machine that can actuary detect a physical amount of a movement of a fabric without depending on an estimated value. Thus, thread tension can be precisely adjusted. A sewing machine 1 includes a spherical body 22a exposed partly from a needle plate 2. The spherical body 22a is rotated following a feed of a fabric 100. The rotation of the spherical body 22a is detected by rotary encoders 22c, 22d. A physical amount of the movement of the fabric 100 is calculated based on a detection result of the rotary encoders 22c, 22d. The physical amount of the movement of the fabric 100 is, for example, a moving amount and a moving speed.

A system for calibrating one or more optical sensors on a sewing machine includes one or more optical sensors and one or more processors of the sewing machine. The optical sensors are arranged to collect data from one or more features of one or more predefined regions. The processors are for processing the data and are configured to: receive the data; detect and recognize the one or more features of the one or more predetermined regions from the data; calculate one or more accuracy indicators of the one or more features from the data as compared to a known feature; compare the value of the one or more accuracy indicators to one or more indicator thresholds; and adjust a parameter of at least one of the optical sensors based on the comparison between the one or more accuracy indicators and the one or more indicator thresholds.

A sewing apparatus for applying a stitch of thread to a piece of fabric is provided. The apparatus housing includes a platform for supporting a piece of fabric, and contains a grasping member that is moved to grasp and release a thread segment fed through the housing by a needle holder. The needle holder is positioned to hold a needle that has a needle aperture for pass-through, therethrough of the thread segment, and is movable between a withdrawn position, and an advanced position in which the needle holder drives the needle through the piece of fabric to bring the thread segment into position for grasping by the grasping member. The sewing apparatus also including a needle holder driver for driving the movement of the needle holder and a thread puller for pulling the thread segment to an exterior of the housing for a user to cut.

A sewing apparatus for applying a stitch of thread to a piece of fabric is provided. The apparatus housing includes a platform for supporting a piece of fabric, and contains a grasping member that is moved to grasp and release a thread segment fed through the housing by a needle holder. The needle holder is positioned to hold a needle that has a needle aperture for pass-through, therethrough of the thread segment, and is movable between a withdrawn position, and an advanced position in which the needle holder drives the needle through the piece of fabric to bring the thread segment into position for grasping by the grasping member. The sewing apparatus also including a needle holder driver for driving the movement of the needle holder and a thread puller for pulling the thread segment to an exterior of the housing for a user to cut.