KR20100106015A - System for measuring actuator of cellular phone's camera - Google Patents

Abstract

PURPOSE: A system for measuring an actuator of a cellular phone camera is provided to analogize a definition in a certain position of a lens by measuring a tile depending on the displacement caused by an actuator. CONSTITUTION: A displacement sensor(30) senses displacement by irradiating a laser beam for an actuator(20), and a tilt level sensor(25) senses the tilt by irradiating a laser beam for the actuator. A controller(40) converts the displacement and tile levels into an analog signal and measures the driving performance and the tilt level of the actuator through a preset algorithm by using a relayed signal. The controller outputs the driving voltage of the actuator.

Description

Actuator measurement system for mobile phone cameras {SYSTEM FOR MEASURING ACTUATOR OF CELLULAR PHONE'S CAMERA}

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

In recent years, the mobile phone has been widely used to perform functions such as photographing, recording music, receiving DMB broadcasting, as well as transmitting voice and texts with the other party.

As described above, a camera module which performs a photo taking function of a mobile phone which performs various functions includes a lens receiving an incident light of a subject, a bobbin having a coil that focuses on the subject while moving forward by being combined with the lens, and an outside of the bobbin. It consists of a housing equipped with a magnet for advancing the bobbin by an electromagnetic force and an actuator including a printed circuit board. It is supposed to focus with and photograph.

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

In particular, when there is a change in the actuator driving performance characteristics of the camera module, the bobbin of the actuator is not taken at the exact distance (point) from the subject, but the shot is taken out of the shooting point, resulting in a defect in resolution. There is a problem.

Thus, the assembled actuator measures the drive performance characteristics. In the related art, the performance was measured using a displacement sensor or the tilt was measured using an inclination sensor. As a result, displacement with respect to current (voltage), tilt with respect to current (voltage), Y-axis tilt with respect to X-axis tilt, and the like could be measured.

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 resolution by checking the characteristics of the tilt at an arbitrary position (displacement) of the actual lens, but it is impossible to confirm this because the displacement value and the tilt value are each measured as described above. It was.

Accordingly, an object of the present invention is to provide an actuator measuring system capable of accurately measuring tilt characteristics at any position of actuator driving performance of a mobile phone camera.

In order to realize the above object, the present invention is an actuator mounted on a jig; Displacement sensor for detecting the displacement by irradiating the laser light to the actuator; An inclination sensor for detecting a tilt by irradiating a laser light to the actuator; A controller for converting the displacement sensed by the displacement sensor and the tilt sensed by the gradient sensor into an analog signal; A repeater for relaying the analog signal converted by the controller; And a controller which receives the signal relayed by the repeater and measures the driving performance and the gradient performance of the actuator by a predetermined algorithm, and outputs the driving voltage of the actuator, wherein the controller is configured to input the displacement value and the tilt value. Based on the above algorithm, a displacement versus tilt waveform is output.

According to the above structure, the tilt sensor and the displacement sensor are used to measure the tilt according to the displacement in addition to the performance according to the current vs. displacement or the current vs. slope, or in which direction the actuator moves in the X and Y axes. And analysis to infer the amount of resolution at any location of the lens.

In addition, it is possible to shorten the measurement time in mass production and to reduce the number of facilities.

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 according to an embodiment of the present invention.

Referring to FIG. 1, the tilt measurement 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 mount and fix the actuator 20 to be measured, and to fix the actuator 20 to X, Y, and Z-axis stages.

The actuator 20 is a driving unit of the camera module and drives back and forth to focus on a subject to be photographed. As described above, the actuator 20 is a housing and a printed circuit board provided with a bobbin with a coil that focuses on a subject while moving forward and backward combined with a lens, and a magnet that advances the bobbin with an electromagnetic force on the outside of the bobbin. It is composed.

The displacement sensor 30 emits laser light from the lower part of the actuator 20 fixed to the jig 10 to detect the displacement of the laser light according to the movement of the actuator 20, and includes a laser light emitting part and a light receiving part.

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

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

The computer 60 includes a conventional desktop or notebook computer that calculates, compares, and judges an input signal, and displays the determined state on a monitor, and collects data inside the computer 60 to collect data. Device (DAQ) 62 and any algorithms needed for the measurement.

The algorithm included in the computer 60 includes a start voltage (START VOLTAGE) or a start current (START CURRENT) at the point where the actuator 20 starts to move, and a displacement difference between when the actuator 20 rises and falls ( HYSTERESIS), the displacement of the actuator 20 at a constant voltage or current position, the distance the actuator moves to the stopper (STROKE), the voltage (Macro Voltage) or current when the actuator 20 reaches the Macro (close-up) position. (Macro Current), the slope of the drive voltage and displacement of the actuator 20, integral non linearity (INL) showing the change of the slope within a specified interval, differential nonlinearity (DNL) 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, differential equation, calculation using angle, calculation It is measured by the point where the optimal slope at and the X point meet.

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

According to the configuration as described above, in the state that the actuator 20 is fixed to the X-axis and Y-axis of the jig 10, the start voltage or start that meets the specification of the actuator 20 to be measured through the input of the computer 60 Enter the current, displacement, distance, slope, resistance, and slope.

Subsequently, when the measurement is started through the input of the computer 60, the data collection device 62 of the computer 60 outputs a driving voltage (or current) to the amplifier 70, and the amplifier 70 outputs the driving voltage to the actuator. The amplified voltage (or current) is input to the data collection device 62 of the computer 60 while amplifying and inputting a voltage (or current) of a size capable of driving the 20. At this time, the input voltage (or current) is input as a triangular wave as shown in FIG.

The actuator 20 starts a movement (movement) by the input driving voltage, and the displacement sensor 30 irradiates a laser light to emit a reflected light signal according to the movement of the actuator 20 from the minimum point to the maximum point. After receiving and converting into an analog signal through the controller 40, it is input to the data collection device 62 of the computer 60 through the repeater 50. In addition, the inclination sensor 25 located on the upper part of the actuator 20 receives a change in inclination from the time when the actuator 20 starts to move by irradiating a laser light as a reflected optical signal and converts it into an analog signal through the controller 40. After the conversion, the data is input to the data collection device 62 of the computer.

Herein, it is determined whether the actuator 20 is good or not using the displacement value and the gradient value which are analog signals input to the data collection device 62 of the computer 60.

Specifically, the data collection device 62 of the computer 60 collects the linear waveform displacement by the DC voltage as shown in Figure 2 (b) according to the movement of the actuator 20, the computer 60 (B) calculates the waveform displacement signal of FIG. 2 (b) and the input voltage of FIG. 2 (a) by a predetermined algorithm, and generates a hysteresis curve waveform as shown in FIG. Output

Based on the hysteresis curve waveform output as described above, a predetermined algorithm is used to measure and calculate a start voltage or start current, displacement, distance, and slope.

That is, in the measurement and calculation of the actuator 20, in the hysteresis curve (y = ax + b) of FIG. 2 (c), a finds a slope by finding two arbitrary points x and y coordinates, and the value of b denotes an x-axis, Can be obtained by entering the y-axis.

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

In addition, the displacement (HYSTERESIS) can be found by inputting the total number of data to be calculated when setting and calculating the displacement difference between rising and falling voltage, and calculating the displacement value that can be moved to the maximum value. This is done by checking the voltage at that time.

The distance STROKE finds the y coordinate value by inputting the x coordinate value of a specific position at y = ax + b and finding an approximation corresponding to the x coordinate value. That is, it finds in the state which arrange | positions the displacement value with respect to voltage.

In addition, the slope SENSITIVITY is calculated by inputting an approximate x, y coordinate of any two points at y = ax + b or using an optimal adjustment method.

The slope may use a best fitting method that converts the data into the most ideal line by using data within the interval of two points.

The measured value through this process is compared with the preset start voltage, start current, displacement, distance, integer nonlinearity, differential nonlinearity, and slope according to the specification of the actuator 20, and the measured value of the actuator 20 is preset. If it is within the input range, it is determined to be good, and if it is out of the preset input range, it is determined to be bad.

In addition, the tilt value received from the tilt sensor 25 can be used to determine where the tilt occurs in the X or Y position, and the current or the tilt value from the tilt sensor 25 and the value of the input voltage or input current. The tilt value can be measured against the voltage.

In addition, using the displacement value of the displacement sensor 30 and the tilt value of the inclination sensor 25, it is possible to measure the tilt value at a specific displacement or the tilt value at a specific displacement section, which is generally important in an actuator for a camera module. It is possible to obtain a tilt value near infinity, i.e., a displacement from 0 to 30 µm, a tilt value near a macro, or a tilt value within an entire section or a set section.

Figure 3 shows the displacement vs. tilt waveform calculated by the above process, it is possible to check the tilt at a specific displacement bar, it is possible to infer the resolution in the camera module by checking the tilt in macro or infinity. Here, X axis represents displacement and Y axis represents tilt.

In the above description, the embodiment of the present invention has been described, but various changes can be made at the level of those skilled in the art. For example, the computer may be configured as a control unit that performs the same function, and the whole computer may be configured as a single measuring device. In addition, in the above embodiment, although the inclination sensor is positioned as an upper portion of the actuator as an example, it may alternatively be located in the lower portion of the actuator.

Therefore, the scope of the present invention should not be construed as being limited to the above embodiment, but should be interpreted by the claims described below.

1 is a block diagram of an actuator measurement system according to an embodiment of the present invention.

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

3 shows the displacement versus tilt waveform by the displacement value and the tilt value.

Claims (4)

An actuator mounted on a jig; A displacement sensor for detecting a displacement by irradiating a laser beam to the actuator; An inclination sensor for detecting a tilt by irradiating a laser light to the actuator; A controller for converting the displacement sensed by the displacement sensor and the tilt sensed by the gradient sensor into an analog signal; A repeater for relaying the analog signal converted by the controller; And A control unit for receiving the signal relayed by the repeater and measuring the driving performance and the slope performance of the actuator by a predetermined algorithm and outputting the driving voltage of the actuator, And the controller outputs a displacement versus tilt waveform through the algorithm based on the input displacement value and the tilt value. The method of claim 1, The displacement sensor and the gradient sensor, the actuator measuring system of the mobile phone camera including a light emitting unit for emitting a laser light and a light receiving unit for collecting the reflected laser light. The method of claim 1, And said inclination sensor is located above or below said actuator, and said displacement sensor is located below or above said actuator. The method of claim 1, The control unit is an actuator measuring system of a mobile phone camera consisting of a computer device having a data collection device for collecting data therein.

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