Camera module and electronic device having same
An electronic device is provided. The electronic device includes a housing, a lens assembly disposed along an optical axis, and an AF actuator. The AF actuator includes a first AF magnet disposed on a first surface of the lens assembly facing a first direction, a second AF magnet disposed on a second surface facing a direction opposite to the first direction with respect to the lens assembly, a first AF coil disposed inside the housing to face the first AF magnet, a first driving circuit disposed at the center of the first AF coil to control a current applied to the first AF coil, a second AF coil disposed inside the housing to face the second AF magnet, and a second driving circuit disposed at the center of the second AF coil to control a current applied to the second AF coil.
1 . An electronic device comprising:
a housing;
a lens assembly comprising at least one lens aligned along an optical axis; and
an auto-focus (AF) actuator to move the lens assembly within the housing, wherein the AF actuator comprises:
a first AF magnet disposed on a first side of the lens assembly,
a second AF magnet disposed on a second side of the lens assembly opposite to the first side,
a first AF coil disposed to face the first AF magnet,
a first position sensor configured to detect a first position of the first AF magnet,
a second AF coil disposed to face the second AF magnet,
a second position sensor configured to detect a second position of the second AF magnet,
a first AF driver integrated circuit (IC) including first memory configured to store a first calibration value and a first driving circuit configured to control a current applied to the first AF coil based on the first position of the first AF magnet detected via the first position sensor,
a second AF driver IC including second memory configured to store a second calibration value and a second driving circuit configured to control a current applied to the second AF coil based on the second position of the second AF magnet detected via the second position sensor to move the lens assembly in a direction of the optical axis, the second memory being separate from the first memory,
wherein the first driving circuit and the second driving circuit are configured to allow opposite ends of the AF actuator to have substantially a same stroke,
wherein the current applied to the second AF coil is different from the current applied to the first AF coil,
wherein the first AF driver IC is disposed inside a periphery of the first AF coil and configured to control the first driving circuit based on the first calibration value stored in the first memory, and
wherein the second AF driver IC is disposed inside a periphery of the second AF coil and configured to control the second driving circuit based on the second calibration value stored in the second memory.
2 . The electronic device of claim 1 ,
wherein the first driving circuit is further configured to control the current applied to the first AF coil based on the first position and the second position, and
wherein the second driving circuit is further configured to control the current applied to the second AF coil based on the first position and the second position.
3 . The electronic device of claim 1 , wherein the first driving circuit is configured to control the current applied to the first AF coil or the second driving circuit is configured to control the current applied to the second AF coil to compensate for a tilt of the lens assembly based on at least one of the first position or the second position.
4 . The electronic device of claim 1 , further comprising:
third memory,
wherein the:
first calibration value is related to the current applied to the first AF coil via the first driving circuit, and
wherein the second calibration value is related to the current applied to the second AF coil via the second driving circuit.
5 . The electronic device of claim 4 , further comprising at least one processor,
wherein the third memory stores computer-executable instructions that, when executed by the at least one processor individually or collectively, causing the electronic device to:
determine a first value for controlling the current applied to the first AF coil based on the first calibration value stored in the first memory, and
determine a second value for controlling the current applied to the second AF coil based on the second calibration value stored in the second memory.
6 . The electronic device of claim 4 , further comprising at least one processor,
wherein the third memory stores computer-executable instructions that, when executed by the at least one processor individually or collectively, cause the electronic device to determine a first calibration position by mapping a height of the first AF magnet from a reference position based on the first calibration value, and determine a second calibration position by mapping a height of the second AF magnet from the housing based on the second calibration value.
7 . The electronic device of claim 6 ,
wherein the first driving circuit is configured to control the current applied to the first AF coil based on a comparison of the first calibration position and a first current position measured via the first position sensor, and
wherein the second driving circuit is configured to control the current applied to the second AF coil based on a comparison of the second calibration position and a second current position measured via the second position sensor.
8 . The electronic device of claim 6 , wherein the third memory stores computer-executable instructions that, when executed by the at least one processor individually or collectively, further cause the electronic device to determine that tilt compensation is required when a difference between the first calibration position and the second calibration position is greater than or equal to a threshold value.
9 . The electronic device of claim 1 ,
wherein the first position sensor comprises a first AF Hall sensor therein, and the second position sensor comprises a second AF Hall sensor therein,
wherein the first driving circuit is configured to measure a position of the first AF magnet relative to the first AF Hall sensor by using the first AF Hall sensor, and
wherein the second driving circuit is configured to measure a position of the second AF magnet relative to the second AF Hall sensor by using the second AF Hall sensor.
10 . The electronic device of claim 1 ,
further comprising at least one AF ball, and
wherein the AF actuator is configured to control the lens assembly to move in the optical axis direction by rolling of the at least one AF ball.
11 . The electronic device of claim 1 ,
further comprising at least one AF shaft, and
wherein the AF actuator is configured to control the lens assembly to move in the optical axis direction by sliding of the at least one AF shaft.
12 . The electronic device of claim 1 , further comprising:
a prism; and
an image sensor configured to acquire light passing through the lens assembly and the prism,
wherein the prism is disposed to refract a path of light passing through the lens assembly toward the image sensor, or disposed to refract a path of light to be incident to the lens assembly.
13 . The electronic device of claim 1 , further comprising:
an AF driver integrated circuit (IC) connected to the first driving circuit and the second driving circuit,
wherein the AF driver IC is configured to control each of the first driving circuit and the second driving circuit.
14 . The electronic device of claim 1 ,
wherein first driving circuit is configured to control the current applied to the first AF coil further based on the second position of the second AF magnet with respect to the second position sensor, and
wherein the second driving circuit is configured to control the current applied to the second AF coil further based on the first position of the first AF magnet with respect to the first position sensor.
15 . A camera module comprising:
a housing;
a lens assembly comprising at least one lens aligned along an optical axis; and
an auto focus (AF) actuator to move the lens assembly within the housing,
wherein the AF actuator comprises:
a first AF magnet disposed on a first side of the lens assembly,
a second AF magnet disposed on a second side opposite to the first side of the lens assembly,
a first AF coil disposed to face the first AF magnet,
a first position sensor configured to detect a first position of the first AF magnet,
a second AF coil disposed to face the second AF magnet,
a second position sensor configured to detect a second position of the second AF magnet,
a first AF driver integrated circuit (IC) including first memory configured to store a first calibration value and a first driving circuit configured to move the lens assembly in the optical axis by controlling current applied to the first AF coil,
a second AF driver IC including second memory configured to store a second calibration value and a second driving circuit configured to move the lens assembly in the optical axis by controlling current applied to the second AF coil, the second memory being separated from the first memory,
wherein the first driving circuit and the second driving circuit is configured to allow opposite ends of the AF actuator to have substantially same stroke,
wherein the current applied to the second AF coil is different from the current applied to the first AF coil,
wherein the first AF driver IC is disposed inside a periphery of the first AF coil and configured to control the first driving circuit based on the first calibration value stored in the first memory, and
wherein the second AF driver IC is disposed inside a periphery of the second AF coil and configured to control the second driving circuit based on the second calibration value stored in the second memory.
16 . The camera module of claim 15 ,
wherein first calibration value is related to the current applied to the first AF coil via the first driving circuit, and
wherein the second calibration value is related to the current applied to the second AF coil via the second driving circuit.
17 . The camera module of claim 16 ,
wherein the first driving circuit is configured to control the current applied to the first AF coil based on the first calibration value, and
wherein the second driving circuit is configured to control the current applied to the second AF coil based on the second calibration value.
18 . The camera module of claim 17 , wherein the first calibration value and the second calibration value are values that compensate for a tilt generated from a height difference between a first surface and a second surface of the lens assembly with respect to a reference position.
19 . The camera module of claim 18 ,
wherein the first position sensor comprises a first AF Hall sensor therein and is configured to measure a position of the first AF magnet relative to the first AF Hall sensor via the first AF Hall sensor, and
wherein the second position sensor comprises a second AF Hall sensor therein and is configured to measure a position of the second AF magnet relative to the second AF Hall sensor via the second AF Hall sensor.
20 . The camera module of claim 19 , wherein the first driving circuit is configured to:
measure a first current position, which is a height of the first AF magnet from the reference position, via the first AF Hall sensor,
compare a first calibration position determined based on the first calibration value with the first current position, and
move the lens assembly in a direction of the optical axis by controlling the current applied to the first AF coil based on a comparison result, and wherein the second driving circuit is configured to:
measure a second current position, which is a height of the second AF magnet from the reference position, via the second AF Hall sensor,
compare a second calibration position determined based on the second calibration value with the second current position, and
move the lens assembly in the optical axis direction by controlling the current applied to the second AF coil based on a comparison result.