Electronic device including structure for detecting rotation amount of motor
An electronic device includes a first housing, a second housing slidably coupled to the first housing, a rollable display configured to be enlarged or reduced based on a movement of the second housing, a rack gear disposed on the second housing, a pinion gear driven in engagement with the rack gear and including a plurality of teeth, an actuator configured to rotate the pinion gear and coupled with the pinion gear by a shaft, a first magnet surrounding at least part of the shaft, and spaced apart from the pinion gear along the shaft, and a hall sensor spaced apart from the pinion gear in direction perpendicular to the shaft, and a processor, wherein the processor is configured to obtain data related to a change in the magnetic force using the hall sensor and identify a rotating angle of the pinion gear based on the data related to a change in the magnetic force.
1 . An electronic device comprising:
a housing including a first housing part and a second housing part movably coupled relative to the first housing part between a retracted position and an extended position;
a flexible display coupled to the housing, wherein a size of an area of the flexible display that is visible from an outside of the electronic device changes as the second housing part is moved relative to the first housing part;
at least one magnet;
a rack gear coupled to the housing;
a pinion gear configured to be engaged with the rack gear;
an actuator configured to rotate the pinion gear;
a hall sensor is configured to detect a magnetic field changed by rotation of the pinion gear, and
a metal plate including a ferromagnetic material to induce magnetic field;
wherein the hall sensor is disposed at between the metal plate and the pinion gear,
wherein a relative position between the at least one magnet and the hall sensor is maintained while the pinion gear is rotated, and
at least one processor comprising processing circuitry;
memory storing instructions that, when executed by the at least one processor individually or collectively, cause to electronic device to:
obtain, through the hall sensor, data indicating the magnetic field changed by rotating the pinion gear; and
identify a rotating angle and/or a rotating direction of the pinion gear based on the data related to a change in the magnetic field.
2 . The electronic device of claim 1 , wherein a distance between the at least one magnet and the hall sensor is maintained while the second housing part is moved relative to the first housing part between the retracted position and the extended position.
3 . The electronic device of claim 1 , wherein the at least one magnet comprises a first magnet and a second magnet facing the first magnet with respect to a shaft of the actuator coupled to the pinion gear, and
wherein a polarity of the first magnet toward the shaft is the same as a polarity of the second magnet toward the shaft.
4 . The electronic device of claim 1 , further comprising:
a printed circuit board having a surface connected to the hall sensor; and
wherein the metal plate disposed on another surface of the printed circuit board; and
wherein the pinion gear overlaps the metal plate, when viewing the metal plate from above.
5 . The electronic device of claim 1 ,
wherein the pinion gear is disposed between the at least one magnet and the actuator.
6 . The electronic device of claim 1 ,
wherein the at least one magnet is disposed between the pinion gear and the actuator.
7 . The electronic device of claim 1 ,
wherein the pinion gear comprises a ferromagnetic material.
8 . The electronic device of claim 1 , further comprising:
a motor housing surrounding the actuator and surrounding a portion of the pinion gear, and comprising a paramagnetic material; and
wherein the at least one magnet is disposed within the motor housing.
9 . The electronic device of claim 8 , wherein the motor housing includes a support rotatably supporting a shaft of the actuator coupled to the pinion gear and a bearing disposed between the support part and the shaft.
10 . The electronic device of claim 9 , wherein the at least one magnet is attached to a surface facing the pinion gear of the support on which the bearing is disposed.
11 . The electronic device of claim 1 , wherein the magnetic field generated by the at least one magnet includes a line forming a closed curve passing through the pinion gear.
12 . The electronic device of claim 1 , wherein a magnitude and a direction of a magnetic field detected by the hall sensor changes sinusoidally based on a distance between a tooth of the pinion gear and one surface of the hall sensor.
13 . The electronic device of claim 1 ,
wherein the instructions, when executed by the at least one processor individually and collectively, cause the electronic device to:
identify the area of the flexible display by identifying the rotating angle and/or the rotating direction of the pinion gear based on the data related to a change in the magnetic field.
14 . The electronic device of claim 13 , wherein the instructions, when executed by the at least one processor individually and collectively, cause the electronic device to:
identify a movement distance of the second housing part based on the rotating angle and/or the rotating direction of the pinion gear based on the data related to a change in the magnetic field, and
identify the area of the flexible display based on the movement distance.
15 . A power transmission device comprising:
a motor housing including a first space and a second space distinct from the first space;
a motor disposed within the first space in the motor housing;
a shaft disposed within the second space, the shaft extending from the motor and configured to be rotated by the motor;
a partition wall separating the first space and the second space;
a pinion gear disposed within the second space, the pinion gear coupled to the shaft and including a plurality of teeth;
a first magnet;
a second magnet facing the first magnet with respect to the shaft;
a hall sensor configured to detect a magnetic field changed by rotation of the pinion gear, and
a metal plate including a ferromagnetic material to induce magnetic field; and
wherein a relative position among the first magnet, the second magnet and the hall sensor is maintained while the pinion gear is rotated, and
wherein a polarity of surfaces of the first magnet and the second magnet facing each other is the same.
16 . The power transmission device of claim 15 , further comprising:
a rack gear including a plurality of teeth disposed on a plane having a length and engaging with the pinion gear.
17 . A power transmission device comprising:
a motor housing including a first space and a second space distinct from the first space;
a motor disposed within the first space in the motor housing;
a shaft disposed within the second space, the shaft extending from the motor and configured to be rotated by the motor;
a partition wall separating the first space and the second space;
a pinion gear disposed within the second space, the pinion gear coupled to the shaft and including a plurality of teeth;
at least one magnet;
a hall sensor configured to detect a magnetic field changed by rotation of the pinion gear, and
a metal plate including a ferromagnetic material to induce magnetic field; and
wherein a relative position between the at least one magnet and the hall sensor is maintained while the pinion gear is rotated, and
wherein the at least one magnet includes a through hole through which the shaft passes.
18 . The power transmission device of claim 15 , further comprising:
a printed circuit board having a surface connected to the hall sensor; and
wherein the metal plate is disposed on another surface of the printed circuit board, and
wherein the pinion gear overlaps the metal plate, when viewed in a direction from the pinion gear toward the hall sensor.
19 . The power transmission device of claim 15 , wherein the pinion gear is disposed among the first magnet, the second magnet and the motor.