Abstract: A level change point detection section detects a level change point, at which an output level switches, in a first position detection signal Ens1 generated by an encoder or a second position detection signal obtained by increasing the resolution of the Ens1. Each time a predetermined number of level change points is detected, an energization timing determination section determines the timing, at which the predetermined number of level change points have been detected, to be an energization timing for the thermal head.

Abstract: A level change point detection section detects a level change point, at which an output level switches, in a first position detection signal Ens1 generated by an encoder or a second position detection signal obtained by increasing the resolution of the Ens1. Each time a predetermined number of level change points is detected, an energization timing determination section determines the timing, at which the predetermined number of level change points have been detected, to be an energization timing for the thermal head.

Abstract: A control method of a media conveyance device enables accurately detecting media slack by a detection mechanism with multiple emitters and multiple photodetectors disposed opposite the emitters. A printer (media conveyance device) has a controller that controls a delivery mechanism, a conveyance mechanism that conveys media, a delivery mechanism, and a conveyance mechanism, and controls conveying roll paper; a first detector including a first emitter and first photodetector; and a second detector including a second emitter and second photodetector. When driving the conveyance mechanism, the controller selectively controls the first emitter and first photodetector to emit, and drives a spindle based on signal output from the first detector when first emitter emits, and signal output from the second detector when second emitter emits.

Abstract: A control method of a media conveyance device enables accurately detecting media slack by a detection mechanism with multiple emitters and multiple photodetectors disposed opposite the emitters. A printer (media conveyance device) has a controller that controls a delivery mechanism, a conveyance mechanism that conveys media, a delivery mechanism, and a conveyance mechanism, and controls conveying roll paper; a first detector including a first emitter and first photodetector; and a second detector including a second emitter and second photodetector. When driving the conveyance mechanism, the controller selectively controls the first emitter and first photodetector to emit, and drives a spindle based on signal output from the first detector when first emitter emits, and signal output from the second detector when second emitter emits.

Abstract: A printer 1 has a movable member 27 that can move following change in the tension on recording paper 3 between a roll paper compartment 7 and a conveyance mechanism 12 on the paper conveyance path 8. When recording paper 3 of which the end is glued to the core 2a of a paper roll 2 runs out, the tension on the recording paper 3 rises and the movable member 27 goes to a tension-side error determination range E1 in its range of allowable movement E0. When the movable member 27 is in the tension-side error determination range E1, the time the movable member 27 remains in the tension-side error determination range E1 is counted, and if this measured time exceeds an error determination time, an error detection unit 38 detects an error. No-paper errors can therefore be detected without using a dedicated sensor.

Abstract: An inkjet printer has a mechanism to counter change in the tension of the recording medium to convey the recording medium with more precision. Such printer has a media conveyance mechanism that conveys a recording medium; an inkjet printhead that prints on the conveyed medium when the printhead is located at a position opposed to the media conveyance mechanism; a media supply mechanism that supplies the medium to the media conveyance mechanism; a lever that is positioned between the media conveyance and media supply mechanisms and that moves to compensate and thus counter internal tension changes in the recording medium resulting from operation of these mechanisms; a detector that detects the movement or position of the lever; and a control unit that controls the media supply operation based on output from the detector so that the lever is urged back to or maintained in a home position.

Abstract: A conveyance device including an upstream roller that supplies a sheet medium to be processed to a conveyance path; a downstream roller that conveys the supplied medium to a processing position; and a control unit that, in order to convey the sheet medium at a constant speed, controls driving the upstream roller and the downstream roller using the constant speed as a target speed. The control unit changes the target speed of the upstream roller to eliminate a conveyance difference, which is the difference between the length of media conveyed by the upstream roller and the length of media conveyed by the downstream roller from the start of the conveyance operation, based on the conveyance difference in each conveyance operation.

Abstract: An inkjet printer has a mechanism to counter change in the tension of the recording medium to convey the recording medium with more precision. Such printer has a media conveyance mechanism that conveys a recording medium; an inkjet printhead that prints on the conveyed medium when the printhead is located at a position opposed to the media conveyance mechanism; a media supply mechanism that supplies the medium to the media conveyance mechanism; a lever that is positioned between the media conveyance and media supply mechanisms and that moves to compensate and thus counter internal tension changes in the recording medium resulting from operation of these mechanisms; a detector that detects the movement or position of the lever; and a control unit that controls the media supply operation based on output from the detector so that the lever is urged back to or maintained in a home position.

Abstract: A inkjet printer has a mechanism to counter change in the tension of the recording medium to convey the recording medium with more precision. In a method, the position or movement of a movable member is detected by a detector, and the recording medium is conveyed based on output from the detector so that the movable member is maintained in or urged back to a set position. Also, one or more operations are stopped when the movable member moves outside of an allowable movement range. Which operation(s) is or are stopped depends on whether the movable member moves outside its allowable range in a direction that increases or decreases the tension in the recording medium.

Abstract: A printer 1 has a belt conveyor mechanism 18 disposed to a platen unit 8 opposite a printhead 7. The belt conveyor mechanism 18 has three conveyor belts 81 mounted on a belt drive roller 82a and guide rollers 82b to 82d. The conveyor belt 81 curves in a C-shape when seen from outside the belt path where the conveyor belt 81 travels around a guide roller 82c. Another guide roller 82d is positioned outside of the belt path, and contacts the surface (conveyance surface) of the conveyor belt 81 curved in the C-shape. An encoder 84 and inertia member 85A are attached to the rotational shaft 82e of the guide roller 82d. Another inertia member 85B is attached to the output shaft 83a of the conveyor motor 83.

Abstract: When conveyance of the recording paper 3 by the conveyance mechanism 12 stops, the printer 1 supplies power of a specific current level to the supply motor 25. This applies specific torque to the paper roll 2 in the opposite direction as the direction in which tension is applied to the recording paper 3 by a spring 30, and holds the movable member 27 at the same position as when conveyance of the recording paper 3 stopped. The torque applied to the paper roll 2 to hold the print position of the movable member 27 is torque sufficient to hold the paper roll 2 still without rolling, and is less than the torque required to turn the paper roll 2 to maintain constant tension on the recording paper 3. Little current is therefore supplied to the supply motor 25, and the supply motor 25 is prevented from overheating.

Abstract: A inkjet printer has a mechanism to counter change in the tension of the recording medium to convey the recording medium with more precision. In a method, the position or movement of a movable member is detected by a detector, and the recording medium is conveyed based on output from the detector so that the movable member is maintained in or urged back to a set position. Also, one or more operations are stopped when the movable member moves outside of an allowable movement range. Which operation(s) is or are stopped depends on whether the movable member moves outside its allowable range in a direction that increases or decreases the tension in the recording medium.

Abstract: A printer 1 has a belt conveyor mechanism 18 disposed to a platen unit 8 opposite a printhead 7. The belt conveyor mechanism 18 has three conveyor belts 81 mounted on a belt drive roller 82a and guide rollers 82b to 82d. The conveyor belt 81 curves in a C-shape when seen from outside the belt path where the conveyor belt 81 travels around a guide roller 82c. Another guide roller 82d is positioned outside of the belt path, and contacts the surface (conveyance surface) of the conveyor belt 81 curved in the C-shape. An encoder 84 and inertia member 85A are attached to the rotational shaft 82e of the guide roller 82d. Another inertia member 85B is attached to the output shaft 83a of the conveyor motor 83.

Abstract: A printer 1 has a movable member 27 that can move following change in the tension on recording paper 3 between a roll paper compartment 7 and a conveyance mechanism 12 on the paper conveyance path 8. When recording paper 3 of which the end is glued to the core 2a of a paper roll 2 runs out, the tension on the recording paper 3 rises and the movable member 27 goes to a tension-side error determination range E1 in its range of allowable movement E0. When the movable member 27 is in the tension-side error determination range E1, the time the movable member 27 remains in the tension-side error determination range E1 is counted, and if this measured time exceeds an error determination time, an error detection unit 38 detects an error. No-paper errors can therefore be detected without using a dedicated sensor.

Abstract: When conveyance of the recording paper 3 by the conveyance mechanism 12 stops, the printer 1 supplies power of a specific current level to the supply motor 25. This applies specific torque to the paper roll 2 in the opposite direction as the direction in which tension is applied to the recording paper 3 by a spring 30, and holds the movable member 27 at the same position as when conveyance of the recording paper 3 stopped. The torque applied to the paper roll 2 to hold the print position of the movable member 27 is torque sufficient to hold the paper roll 2 still without rolling, and is less than the torque required to turn the paper roll 2 to maintain constant tension on the recording paper 3. Little current is therefore supplied to the supply motor 25, and the supply motor 25 is prevented from overheating.

Abstract: A printer has a mechanism to counter change in the tension of the recording medium to convey the recording medium with more precision. Such printer has a media conveyance mechanism that conveys a recording medium; a printhead that prints on the medium; a media supply mechanism that supplies the medium to the media conveyance mechanism; a movable member that can move to compensate and thus counter internal tension changes in the recording medium resulting from operation of the media conveyance and supply mechanisms; a detector that detects the movement or position of the movable member; and a control unit that controls the media supply operation based on output from the detector so that the movable member is urged back to or maintained in a home position.

Abstract: A conveyance device including a drive roller that feeds a sheet medium from a media roll having the sheet medium wound in a roll that can rotate on a center axis of the roll, a drive roller that supplies the sheet medium from the media roll, a roll rotating unit that rotates the media roll and rewinds the supplied sheet medium, and first and second brake devices that apply a load to rotation of the media roll and are disposed to the roll rotating unit, wherein the first brake device is controlled to apply the load when not energized.

Abstract: A printer has a mechanism to counter change in the tension of the recording medium to convey the recording medium with more precision. Such printer has a media conveyance mechanism that conveys a recording medium; a printhead that prints on the medium; a media supply mechanism that supplies the medium to the media conveyance mechanism; a movable member that can move to compensate and thus counter internal tension changes in the recording medium resulting from operation of the media conveyance and supply mechanisms; a detector that detects the movement or position of the movable member; and a control unit that controls the media supply operation based on output from the detector so that the movable member is urged back to or maintained in a home position.

Abstract: A conveyance device including a drive roller that feeds a sheet medium from a media roll having the sheet medium wound in a roll that can rotate on a center axis of the roll, a drive roller that supplies the sheet medium from the media roll, a roll rotating unit that rotates the media roll and rewinds the supplied sheet medium, and first and second brake devices that apply a load to rotation of the media roll and are disposed to the roll rotating unit, wherein the first brake device is controlled to apply the load when not energized.

Abstract: A conveyance device including an upstream roller that supplies a sheet medium to be processed to a conveyance path; a downstream roller that conveys the supplied medium to a processing position; and a control unit that, in order to convey the sheet medium at a constant speed, controls driving the upstream roller and the downstream roller using the constant speed as a target speed. The control unit changes the target speed of the upstream roller to eliminate a conveyance difference, which is the difference between the length of media conveyed by the upstream roller and the length of media conveyed by the downstream roller from the start of the conveyance operation, based on the conveyance difference in each conveyance operation.