KR101625098B1 - System for measuring actuator of cellular phone's camera - Google Patents

Abstract

Disclosed is an actuator measurement system for a mobile phone camera that outputs a displacement-to-tilt waveform. The system comprises: an actuator mounted on a jig; A displacement sensor for sensing a displacement by irradiating the actuator with laser light; An inclination sensor for detecting tilt by irradiating the actuator with laser light; A controller for converting a displacement detected by the displacement sensor and a tilt detected by the tilt sensor into an analog signal; A relay for relaying the converted analog signal from the controller; And a controller for receiving a signal relayed from the relay and measuring a driving performance and a tilt performance of the actuator using a predetermined algorithm, and outputting a driving voltage of the actuator.

Mobile phone camera, camera module, actuator, displacement, tilt, resolution

Description

TECHNICAL FIELD [0001] The present invention relates to an actuator measuring system for a cellular phone camera,

The present invention relates to an actuator measurement system of a mobile phone camera.

In recent years, it has become common that a mobile phone can perform functions such as photo shooting, music recording, and reception of DMB broadcasting, as well as voice and text transmission with the other party.

A camera module that performs a photographing function of a cellular phone that performs various functions as described above includes a lens that receives reflected light of a subject, a bobbin that is coupled with the lens and moves a forward moving coils to focus on the subject, A housing having a magnet for moving the bobbin by electromagnetic force, and an actuator including a printed circuit board. When the photographing function is performed, the bobbin moves forward and backward according to the Fleming's left-hand rule acting between the bobbin and the magnet of the actuator, And the like.

However, the camera module of such a mobile phone often has a change in driving performance characteristics due to assembly defects, component self-defects, and other factors.

In particular, when the actuator driving performance characteristics of the camera module are changed, the bobbin of the actuator is defective such that the shooting is not performed at a precise distance (point) with respect to the object, There is a problem.

Thus, the assembled actuator measures the driving performance characteristics. Conventionally, the performance is measured using a displacement sensor or the tilt is measured using an inclination sensor. As a result, it was possible to measure displacement with respect to current (voltage), tilt with respect to current (voltage), and Y-axis tilt with respect to X-axis tilt.

However, in the actual camera module, it is necessary to measure the tilt of the displacement value from infinity to macro (macro). In other words, it is necessary to infer the amount of resolving power by checking the characteristic of the tilt at an arbitrary position (displacement) of the actual lens. Conventionally, since the displacement value and the tilt value are measured as described above, Respectively.

It is therefore an object of the present invention to provide an actuator measuring system capable of accurately measuring tilt characteristics at any position among actuator driving performances of a mobile phone camera.

In order to achieve the above object, the present invention provides an actuator comprising: an actuator mounted on a jig; A displacement sensor for detecting a displacement by irradiating the actuator with a laser beam; An inclination sensor for detecting tilt by irradiating the actuator with laser light; A controller for converting a displacement detected by the displacement sensor and a tilt detected by the tilt sensor into an analog signal; A relay for relaying the converted analog signal from the controller; And a controller for receiving the signals relayed by the relay and measuring the driving performance and the tilt performance of the actuator with a preset algorithm and outputting the driving voltage of the actuator, And outputs a displacement-tilt waveform based on the algorithm.

According to the above-described structure, by using the inclination sensor and the displacement sensor, the performance depending on the current versus displacement or the performance based on the current versus the inclination, or the inclination occurring as the actuator moves in either direction of the X or Y axis, And analyzed to infer the amount of resolution at any position of the lens.

In addition, the measurement time can be shortened in mass production, and the number of facilities can be reduced.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a tilt measurement system in accordance with an embodiment of the present invention.

Referring to FIG. 1, the tilt measuring system of the present invention includes a jig 10, an actuator 20, an inclination sensor 25, a displacement sensor 30, a controller 40, a repeater 50, a computer 60, And an amplifier (70).

The jig 10 is configured to fix the actuator 20 to be measured and to fix the actuator 20 at the X, Y, and Z axis ends.

The actuator 20 is a driving unit of the camera module and is driven forward and backward to focus on a subject to be photographed. As described above, the actuator 20 includes a housing having a bobbin having a coil wound around the lens and focused on the subject while moving forward and backward, and a magnet for moving the bobbin by electromagnetic force outside the bobbin, and a printed circuit board .

The displacement sensor 30 emits a laser beam from a lower portion of the actuator 20 fixed to the jig 10 to sense the displacement of the laser beam according to the movement of the actuator 20 and comprises a laser emitting portion and a light receiving portion.

The controller 40 converts the laser light signal detected from the displacement sensor 30 into an electrical analog signal and outputs the electrical analog signal, for example, an encoder.

The repeater 50 repeats the analog signal output from the controller 40 and relays the signal input through the BNC cable to each output terminal, for example.

The computer 60 includes a conventional desktop or notebook computer that computes, compares, and judges the input signals and displays the determined states on a monitor. The computer 60 includes a data acquisition (DAQ) 62 and predetermined algorithms necessary for measurement.

The algorithm included in the computer 60 may be such that the start voltage (START VOLTAGE) or the start current (START CURRENT) of the point at which the actuator 20 starts to move, the displacement difference when the actuator 20 moves up and down Hysteresis), a distance at which the actuator 20 moves at a predetermined voltage or current position and a distance at which the actuator moves to the stopper (STROKE), a voltage (Macro Voltage) at which the actuator 20 reaches the Macro A nonlinearity (INL), a nonlinearity (DNL), and a nonlinearity (DNL) showing a change in the slope of the actuator 20, Linearity, Coil Resistance, or Dynamic Tilt.

START VOLTAGE or START CURRENT is the voltage or current at the point where the slope meets the X axis, voltage or current above a certain displacement, total slope and change value, calculation using differential equation, angle, And the point at which the X point meets.

The amplifier 70 amplifies the drive voltage output from the data acquisition device 62 of the computer 60 to a voltage (or current) of a size that the actuator 20 can drive, and the amplified voltage Is supplied to the actuator 20 and is input to the data collection device 62 of the computer 60. If the output voltage of the data acquisition device and the capacity of the output current are large, the amplifier may not be used.

The actuator 20 is mounted on the X axis and the Y axis of the jig 10 and the start voltage or start voltage corresponding to the specification of the actuator 20 to be measured through the input section of the computer 60 Current, displacement, distance, slope, resistance, and slope.

The data collection device 62 of the computer 60 then outputs the drive voltage (or current) to the amplifier 70 and the amplifier 70 drives the drive voltage to the actuator 70 (Or current) of a magnitude sufficient to drive the microcomputer 20 and inputs the amplified voltage (or current) to the data collection device 62 of the computer 60. [ In this case, the input voltage (or current) is inputted as a triangular wave as shown in FIG. 2 (a). In addition, the input voltage (or current) can be inputted in various ways depending on the purpose of measurement such as a step wave or a sine wave.

The actuator 20 starts to move (move) by the input driving voltage. The displacement sensor 30 irradiates the laser light to the actuator 20 to output a reflected optical signal corresponding to the movement from the minimum point to the maximum point Converts it into an analog signal through the controller 40 and then inputs it to the data collection device 62 of the computer 60 via the relay 50. [ The inclination sensor 25 located at the upper portion of the actuator 20 receives the variation of the inclination from the time when the actuator 20 starts to move by irradiating the laser light with the reflected light signal, And then inputted into the data collection device 62 of the computer.

Here, the actuator 20 is determined based on a displacement value and an inclination value, which are analog signals input to the data collection device 62 of the computer 60.

Specifically, the data acquisition device 62 of the computer 60 collects the waveform of the linear waveform by the DC voltage as shown in FIG. 2 (b) according to the motion of the actuator 20, 2 (b) and the input voltage of FIG. 2 (a), which are input to the data collecting device 62 by a predetermined algorithm, to obtain a hysteresis curve waveform as shown in FIG. 2 (c) Output.

The starting voltage or the starting current, the displacement, the distance, and the slope are measured and calculated with a predetermined algorithm predetermined based on the output hysteresis curve waveform.

That is, the measurement and calculation of the actuator 20 are performed by finding a slope by finding a two arbitrary point x and y coordinates in a hysteresis curve (y = ax + b) of FIG. 2 (c) y axis.

Therefore, the starting voltage and the starting current can be obtained by finding a point where two lines meet by using the function y = ax + b and y = 0.

In addition, the displacement (HYSTERESIS) is calculated by calculating the displacement difference at the time of rising and falling with respect to the voltage by inputting the total number of data to be calculated at the time of setting, calculating the displacement value at which the maximum displacement can be moved to the maximum value It can be obtained by checking the voltage at that time.

The distance (STROKE) inputs the x-coordinate value of a specific position at y = ax + b, finds an approximation corresponding to the x-coordinate value, and finds the y-coordinate value. That is, a displacement value with respect to a voltage is found in an arrayed state.

Also, the SENSITIVITY is calculated by inputting the approximate x and y coordinates of any two points at y = ax + b or by using the optimal adjustment method.

The slope may be a best fitting method that transforms the data into the most ideal line using the data in the two points.

The measured values are measured according to the specifications of the actuator 20, and compared with the predetermined start voltage, the start current, the displacement, the distance, the nonlinearity of the integer, the nonlinearity and the slope of the differential, If it is within the input range, it is judged to be good. On the other hand, if it is out of the preset input range, it is judged to be defective.

Also, the tilt value received from the tilt angle sensor 25 can be used to check the tilt at any position of X or Y, and the tilt value from the tilt angle sensor 25, The tilt value for the voltage can be measured.

Further, it is possible to measure a tilt value at a specific displacement or a tilt value at a specific displacement interval by using the displacement value of the displacement sensor 30 and the tilt value of the tilt sensor 25. In general, It is possible to obtain a tilt value in the vicinity of infinity, that is, a tilt value in the vicinity of 0 to 30 mu m as a displacement, a tilt value in the vicinity of the close-contact, or a tilt value in the entire section or set interval.

FIG. 3 shows a displacement-to-tilt waveform calculated by the above procedure. As shown in FIG. 3, the tilt at a specific displacement can be confirmed. Here, the X-axis represents the displacement and the Y-axis represents the tilt.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, the computer can be configured as a control unit that performs the same function, and the entirety can be configured as one measurement device. In the above embodiment, the inclination sensor is located at the upper portion of the actuator. Alternatively, the inclination sensor may be located at the lower portion of the actuator.

Accordingly, the scope of the present invention should not be construed as being limited to the embodiments described above, but should be construed in accordance with the following claims.

1 is a block diagram of an actuator measurement system in accordance with an embodiment of the present invention.

2 (a), (b) and (c) are measured input and output waveform diagrams of an actuator measurement system of a mobile phone camera according to an embodiment of the present invention.

3 shows a displacement-tilt waveform based on a displacement value and a tilt value.

Claims (4)

An actuator mounted on a jig; A displacement sensor for sensing a displacement by irradiating the actuator with laser light; An inclination sensor for detecting tilt by irradiating the actuator with laser light; A controller for converting a displacement detected by the displacement sensor and a tilt detected by the tilt sensor into an analog signal; A relay for relaying the converted analog signal from the controller; And And a controller for receiving a signal relayed from the repeater and measuring a driving performance and a tilt performance of the actuator using a predetermined algorithm and outputting a driving voltage of the actuator, Wherein the controller outputs the displacement-tilt waveform through the algorithm based on the input displacement value and the tilt value. The method according to claim 1, Wherein the displacement sensor and the tilt sensor include a light emitting portion for emitting laser light and a light receiving portion for collecting reflected laser light. The method according to claim 1, Wherein the tilt sensor is located at the top or bottom of the actuator and the displacement sensor is located at the bottom or top of the actuator. The method according to claim 1, Wherein the control unit comprises a computer device having a data collection device for collecting data therein.

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