KR20100048641A - Method for adjusting auto focus and camera having a function of the same - Google Patents

Abstract

PURPOSE: A method for adjusting auto focus and camera having a function of the same are provided to reduce time which auto focusing adjustment is completed to accurately perform the adjustment of auto focusing. CONSTITUTION: An ISP(Image Signal Processor)(20) process a video signal which is inputted from an image sensor. A distance measurer(30) measures a distance with an object. A controller(40) adjusts location of focus lens corresponding to the distance measured from the distance measurer. The controller calculates a focus adjustment value about different locations. The controller readjusts a location of focus lens to a location which shows optimum focus adjustment value.

Description

METHOD FOR ADJUSTING AUTO FOCUS AND CAMERA HAVING A FUNCTION OF THE SAME}

The present invention relates to a camera, and more particularly, to a method for performing autofocus adjustment of a camera and an apparatus therefor.

Conventional cameras include a lens system for forming an image of a subject on a film or an image sensor, and an image sensor for detecting an image formed by the lens as an electrical signal. do. The focus of the lens unit also changes according to the distance between the lens and the subject. Only when the amount of change in the position of the image plane according to the position of the subject is within the depth of focus range of the camera, it is possible to capture a high quality photograph.

Therefore, a conventional camera requires a function capable of automatically adjusting focus according to a change in distance from a subject, that is, an auto focus (AF) function, in order to capture a high quality photograph.

A representative auto focusing algorithm currently in use is hill climbing. The hill climbing autofocus algorithm is a method of finding an optimal focus position by moving a focus lens back and forth at a current position and then moving the focus lens in a direction in which focus is achieved. Specifically, after dividing an area in which the position of the focus lens can move primarily into a plurality of steps, a focus adjustment value for each step of the focus lens is obtained. The point that becomes the largest value among the acquired focus adjustment values is set as the first proper point (PF). Then, a predetermined area around the center around the first proper point is set, and the predetermined area is further divided into a plurality of steps. Then, the focus adjustment value for each step of the focus lens is acquired, and the point which becomes the largest value among the focus adjustment values is set as the final proper point.

The heel climbing method has a problem in that it takes time by the number of steps by moving the focus lens step by step to focus on the subject and detecting the focus adjustment values, and placing the focus lens in the step where the focus adjustment value is maximum. . In addition, the time for performing the auto focus adjustment in the imaging of the image is long, and the continuous auto focus adjustment is not easy when shooting a video, causing a problem that a clear video cannot be taken.

The present invention has been made in view of the above-described point, and an object thereof is to provide a method and apparatus capable of accurately performing autofocus control while reducing the time until the autofocus control is completed.

In addition, another object of the present invention is to provide a method for accurately measuring a distance in various environments by compensating for an error occurring when measuring a distance to be used for automatic priming.

In order to achieve the above object, the automatic focusing method according to an aspect of the present invention is a method for automatically focusing a camera, the process of checking an initial position of a focus lens, a process of measuring a distance from a subject, and a measurement Determining the displacement to which the focus lens should move, moving the focus lens, measuring the focus adjustment value, and adjusting the position of the focus lens to the position representing the optimal focus adjustment value based on the determined distance. do.

According to each type corresponding to a predetermined condition, the method further includes a step of presetting a relationship between a value indicating a distance to a subject and a distance, and the process of measuring the distance to the subject comprises using a distance measuring sensor. Measuring a value indicating a distance, applying a value indicating the measured distance to a type corresponding to a current condition, identifying a region to which the value indicating the distance corresponds, and a subject The method may include calculating a slope of the area based on a relationship between a value indicating a distance and a distance to the distance, and calculating a distance from the subject based on the slope.

The predetermined condition may be a condition that combines photographing information including illumination, reflectance, and color measured by an image signal processor (ISP).

Preferably, the predetermined condition may be a condition including a combination further including temperature information measured by the temperature sensor.

The photographing information preferably includes illumination, reflectance, and color of an area in which the distance measuring sensor indicates the distance.

The process of adjusting the position of the focus lens includes measuring a focus adjustment value by moving a predetermined interval, repeating a predetermined number of times, and moving the focus lens to a position where the focus adjustment value indicates the highest value. It includes the process of making.

It is preferable to adjust the position of the focus lens based on the point where the focus lens is moved based on the measured distance.

The method may further include setting a predetermined interval and a predetermined number of times corresponding to the measured distance.

According to another aspect of the present invention, a camera having an automatic focusing function includes a lens assembly including a fixed lens and a movable focus lens, an encoder for measuring a position of the focus lens, and a drive of the focus lens. An image sensor for receiving a visible light signal of a specific wavelength band reflected from a subject and converting the image signal into an image signal, an image signal processor (ISP) for processing the image signal received from the image sensor; And a distance measurer measuring a distance from a subject, and adjusting a position of a focus lens in response to the distance measured from the distance measurer, and calculating a focus adjustment value for different positions, thereby adjusting the position of the focus lens to an optimal focus. And a control unit for readjusting to a position representing the adjustment value.

The control unit presets a relationship between a distance indicating a distance to a subject and a distance according to each type corresponding to a predetermined condition, and sets a value indicating a distance from a range finder to a current condition. It is preferable to calculate the inclination of the area and the distance to the subject based on the relationship after confirming the area to which the value indicating the distance is applied.

The predetermined condition may be a condition that combines photographing information including illumination, reflectance, and color measured by an image signal processor (ISP).

The apparatus further includes a temperature sensor measuring temperature information and providing the same to the controller, wherein the predetermined condition further includes the temperature information.

The photographing information preferably includes illumination, reflectance, and color of an area in which the distance measuring sensor indicates the distance.

The control unit measures a focus adjustment value by moving a predetermined interval, repeats a predetermined number of times, moves the focus lens to a position where the focus adjustment value indicates the highest value, and adjusts the position of the focus lens. Can be readjusted.

The controller may set a predetermined interval and a predetermined number of times corresponding to the measured distance.

According to the method and apparatus for auto focusing according to the present invention, the position of the focusing lens is adjusted relatively faster by adjusting the position of the focusing lens using distance measurement, and the position of the focusing lens is adjusted using the focusing adjustment value. By precise adjustment, the position of the focus lens can be precisely adjusted.

In addition, by calculating the distance after applying the algorithm that compensates for the error of the rangefinder output, it is possible to accurately and quickly autofocus control in various environments.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, specific matters such as specific elements are shown, which are provided to help a more general understanding of the present invention. It is self-evident to those of ordinary knowledge in Esau.

The automatic focusing method according to the prior art performs hill climbing twice (Coarse Search and Second Search) to adjust the focus lens. Accordingly, by moving the position of the focus lens several times and repeatedly calculating the focus adjustment value at the moved position, it takes a long time until the automatic focus adjustment is completed, there is a problem that a lot of calculations are required.

Accordingly, in the present invention, in order to accurately perform the autofocus control while minimizing the time until the autofocus control is completed, the position of the focus lens is first adjusted by measuring the distance to the subject, and for some weak spots. Secondly, a method of adjusting the position of the focus lens by using the focus adjustment value is proposed. In addition, by applying an algorithm that compensates for the error of the rangefinder output and calculates the distance, we propose a method that can accurately measure the distance in various environments.

1 is a block diagram illustrating a schematic configuration of a camera having an autofocus control function according to an embodiment of the present invention.

Referring to FIG. 1, a camera having an autofocus control function according to an embodiment of the present invention includes an imaging unit 10 for generating an image signal for a projectile and an image signal processor (ISP) for processing the image signal. Signal Processor (20), the distance measuring device 30 to measure the distance to the subject, the controller 40 for controlling the operation of the components provided in the camera, the driving unit 50 for driving the lens, and displays an image The display unit 60 is included.

The image capturing unit 10 is fixed to the front of the camera to form an image capturing lens 11, a focus lens 13 movably aligned behind the image capture lens 11, the focus lens The encoder 17 detects the position of 13 and transmits it to the control unit 40, and an image sensor 15 which receives a visible light signal having a specific wavelength band reflected from the subject and converts it into an image signal.

The image capture lens 11 and the focus lens 13 may be composed of a combination of convex lenses, concave lenses, aspherical lenses and the like. The image capture lens 11 and the focus lens 13 may have rotational symmetry with respect to an optical axis, and the optical axis may be defined as an axis passing through vertices of a plurality of lens surfaces.

The image sensor 15 may be an imaging device such as a complementary metal-oxide semiconductor (CMOS) or a charge-coupled device (CCD).

The encoder 17 detects the position of the focus lens 13 and provides the control unit 40 with a position detection signal indicating the position.

The encoder 17 may be typically implemented by a combination of a Hall sensor and a permanent magnet, which is installed at a lower end of an assembly in which an image capture lens 11 and a focus lens 13 are provided to focus. The position change of the lens 13 is detected. The hall sensor changes its output voltage according to the intensity of the magnetic field applied by the permanent magnet, and the controller 40 determines the position of the focus lens 13 based on the voltage of the position detection signal input from the hall sensor.

The image signal processor (ISP) 20 processes the image signal input from the image sensor 15 in units of frames, and converts the image signal to match the screen characteristics (size, image quality, resolution, etc.) of the display unit 60. Output the frame.

The range finder 30 includes a transmitter Tx for emitting signals such as infrared rays, ultrasonic waves, and lasers, and a receiver Rx for detecting the emission signals reflected by a subject. In addition, the distance measurer 30 checks the time until the emission signal is reflected by the subject and calculates the distance from the subject, and provides the result to the controller 40.

The driver 50 moves the focus lens 13 under the control of the controller 40. For example, the driving unit 50 includes an actuator for providing a driving force, and a carrier for moving the focus lens 13 along its optical axis by the driving force.

The display unit 60 displays an image frame input from the image signal processor (ISP) 20 on the screen. In addition, the display unit 60 may display the autofocus control window on the image frame in the autofocus control procedure on the screen.

The controller 40 provides an algorithm for performing the overall functions of the camera.

In particular, the controller 40 determines the focus position according to the distance of the subject through the auto focus adjustment function, and generates a control signal for positioning the focus lens 13 corresponding to the focus position.

Hereinafter, a process in which the controller 40 performs an auto focusing function will be described in detail with reference to FIGS. 2 to 10.

2 is a flow chart showing the procedure of the automatic focus control method according to an embodiment of the present invention.

Referring to FIG. 2, first, in step S100, the initial value of the focus lens is checked using the encoder 17. That is, the control unit 40 reads the output voltage V _h of the hall sensor provided in the encoder 17. Then, the control section 40 confirms the position of the output voltage (V _h) and the permanent magnet a focusing lens 13 on the basis of the position provided to the encoder 17 for indicating the intensity of the magnetic field.

In operation S200, the controller 40 receives an output voltage V _d indicating the distance from the range finder 30, and measures the distance to the subject using the relationship between the output voltage V _d and the distance. .

In step S200, the output voltage V _d may be used as information indicating a distance without performing a separate compensation. Generally, however, the distance measuring device 30 adjusts the distance by a trigonometry considering the positions of the transmitter Tx that emits light, the subject that reflects the light, and the receiver Rx that detects the emission signal reflected by the subject. Calculate In this case, the surrounding environment, the characteristics of the subject, and the like may affect the output voltage V _d of the range finder 30. Therefore, in order to perform an accurate distance calculation, it is desirable to perform compensation for factors influencing the distance calculation.

In general, the output voltage V _d of the distance meter 30 with respect to the distance varies according to factors such as the type of light source, object reflectivity, color, and ambient temperature. Therefore, a case is set according to a combination of factors influencing the distance calculation, and, through experiments, a table representing the relationship between the distance for each case and the DMS output voltage V _d is generated in advance. It is desirable to. At this time, some of the information on each factor can be confirmed through a value output from the image signal processor (ISP) (20). That is, the type of the light source may be in the AWB state, the reflectivity of the subject may be identified by gradation information, and the color may be identified through the RGB ratio. In addition, the temperature information may be measured using a temperature sensor (eg, thermistor) provided inside the camera to measure temperature information inside the system.

Furthermore, the pre-generated table for each case may be illustrated as shown in FIG. 3. In addition, each type table illustrated in FIG. 3 may be represented by a curve graph representing a relationship between distance vs. DMS output voltage V _d , as shown in FIG. 4, and the curve may be divided into a plurality of regions. The divided regions may be set to predetermined regions (for example, Region 1, Region 2, and Region n). In this case, a portion having a large change rate is set to have a narrow width of a section, and a portion having a small change rate is set to have a wide width of a section, so that a relationship between distance and DMS output can be represented relatively accurately in a specific environment by using limited resources.

On the other hand, each case (case) according to the combination of factors affecting the distance calculation can be illustrated as Table 1 below.

Light source type reflectivity Color Temperature case 1 Direct sunlight White Red 16-20 ^o C case 2 AC light White Red 16-20 ^o C : : : : : case n AC light black blue 0 ~ 5 ^o C

FIG. 5 is a flowchart illustrating in detail the sequence of step S200 of FIG. 2. Referring to FIG. 5, step S200 of FIG. 2 may include steps S210, S220, S230, and S240.

In step S210, the control unit 40 instructs the operation of the range finder 30 having a distance measuring sensor (DMS), and outputs an output voltage V _d indicating the distance from the range finder 30. Get input.

In operation S220, the controller 40 receives factors such as the type of light source, object reflectivity, and color from the image signal processor (ISP) 20, and receives temperature information from a temperature sensor (not shown). Then, a predetermined type is identified in which the input factors correspond to a combined value. In addition, the controller 40 checks whether the output voltage V _d input in step S210 is included in which region of which type.

Meanwhile, referring to FIG. 6, since the range finder 30 is located close to the image pickup unit 10 as illustrated, the light emitted from the actual range finder is a light source of the range finder 30 based on the center of the screen. It is reflected in the spaced apart portion by the distance between the position of and the lens 11 of the imaging unit 10. Therefore, when the information of the distance measuring device 30 is appropriately set based on the center of light reaching among the subjects, information necessary for measuring the distance for auto focusing can be more accurately obtained.

Therefore, in step S220, when receiving information on the type of light source, the reflectivity of the object, the color sense, etc. from the image signal processor (ISP) 20, the specific part of the screen, that is, the distance measurer 30 It is preferable to set the distance measuring part as a window and receive the factors of the part corresponding to the window.

Next, in step S230, the controller 40 calculates the inclination (tilt) of the region (eg, region 1 of FIG. 4) to which the output voltage V _d belongs. For example, the inclination may be obtained by calculating the Y-axis increase amount with respect to the X-axis increase amount of the start point and the end point of the region identified in S220.

When the inclination of the area is calculated through the step S230, the controller 40 calculates the distance to the subject using the inclination (S240). For example, the distance may be obtained through the calculation of Equation 1 below.

D _n , D _{n +1} indicates a distance which is an X-axis variable of FIG. 4, and V _{d , n} , V _{d , n + 1} indicates an output voltage V _d which is a Y-axis variable.

Referring back to FIG. 2, in the auto focus control method according to an embodiment of the present invention, the position of the lens is adjusted based on the distance measured in step S200 (step S300).

In operation S300, the controller 40 may be included in the driver 50 through a relationship between the stroke St of the actuator 50 and the drive voltage V _out (eg, the relationship illustrated in the graph of FIG. 7). The driving voltage V _out for moving the carrier is calculated. The driving voltage V _out may be determined by calculating Equation 2 below.

V _out = αSt + (V _h + V _offset )

α indicates an increase amount of the driving voltage V _out with respect to the unit increase amount of the stroke St shown in the graph of FIG. 7, V _h is an output voltage value of the hall sensor, and V _offset is an error correction of the hall sensor output. Indicates a value.

In operation S300, the controller 40 uses the distance D relationship between the subject and the lens and the distance S relationship between the initial position and the current position of the focus lens 13 as illustrated in FIG. 8. Generates a signal to control). The signal for controlling the driver 50 may be a pulse width modulation (PWM) signal, and the controller 40 may generate a pulse width modulation (PWM) signal by calculating a ratio (Duty). The ratio of the pulse width modulation (PWM) signal may be calculated through Equation 3 below.

Next, in step S400, if the capture signal is input, the process proceeds to step S500, and if the capture signal is not received, steps S200 and S300 are repeated to continuously perform autofocus control even in the preview state.

The capture signal input in step S400 may be information input by the user to instruct to take a picture, for example, a signal generated by the user operating the camera's shutter. In addition, the capture signal input in operation S400 may be a signal for instructing the capturing of each frame included in the video every predetermined time unit (for example, 1/30 second) when the video is captured.

In operation S500, a focus adjustment value of a specific area is calculated based on the position of the focus lens 13 adjusted in operation S300, and the position of the focus lens is adjusted based on the calculated focus adjustment value. In operation S600, the image sensor 15 may provide an image signal captured by the positioned focusing lens 13 to the image signal processing unit (ISP) 20 to capture an image.

9 is a flowchart showing the detailed procedure of S500 of FIG. Referring to FIG. 9, step S500 includes steps S510, S520, S530, S540, S550, S560, and S570.

In operation S510, a focus adjustment value for the position of the focus lens 13 adjusted in operation S300 is calculated. The calculated initial focus adjustment value is temporarily stored in a storage medium such as a buffer or a register.

In step 520, the distance set in step 200 is checked, and whether the set distance is near or far. For example, when the set distance has a value that is relatively smaller than the preset short distance reference value, the distance may be set to a short distance, and when the set distance has a value that is relatively larger than the preset far reference value. In addition, when the set distance indicates a value that is relatively larger than the near reference value and smaller than the far reference value, the distance may be set to an intermediate distance.

In operation 520, when the set distance is determined to be near or far, the focus adjustment value for the specific area may be calculated based on the position of the focus lens 13 adjusted in step S300. The number of steps and the moving distance between steps are set. For example, in a short distance, the specific area is equally divided into four steps, and in a long distance, the specific area is evenly divided into eight steps.

Next, in step 530, the control unit 40 generates a control signal for moving by the step based on the calculated position of the initial focus adjustment value in step S510 and transmits the control signal to the driving unit 50. In response, the driver 50 moves the focus lens 13 one step from the position at which the initial focus adjustment value is calculated.

When the movement of the focus lens 13 is completed in operation 530, the controller 40 calculates a focus adjustment value in step 540, and temporarily stores the calculated focus adjustment value in a storage medium such as a buffer or a register.

In operation S550, after checking the number of movements of the focus lens 13, if the number of movements does not reach the number set in operation S520, the operation S530 and S540 are repeatedly performed. On the other hand, if the focus lens 13 has moved the number of times set in step S520, step S560 is performed.

In operation S560, the controller 40 checks the focus adjustment value having the largest value among the focus adjustment values calculated in each step. In operation S570, a control signal for moving the focus lens 13 to a position corresponding to the appropriate point is generated by using the position of the focus lens 13 corresponding to the focus adjustment value having the largest value as an appropriate point. do.

Hereinafter, operation S500 will be described in more detail with reference to FIG. 10.

10 is a graph illustrating a focus adjustment value calculated according to the position of the focus lens in the autofocus control method according to an embodiment of the present invention. Referring to FIG. 10, when the position of the focus lens 13 adjusted in step S300 is located at a reference point and the set distance is confirmed at a short distance through step S520, the origin of the focus lens 13 and the reference point are determined in step S520. Is divided into four areas and the moving distance between each step is set to L. In operation 530, the focus lens 13 positioned at the reference point is moved by L in the direction of the origin of the focus lens 13, and in operation S540, the focus adjustment value at the moved point is calculated and temporarily stored.

In operation S550, the number of times the focus lens 13 is moved is checked. Since the number of movements does not reach the number set in step S520, the focus lens 13 is moved by one stem in the origin direction of the focus lens 13 by L through step 530. Calculate and temporarily store the focus adjustment value. By repeating these processes (S530, S540, S550), the focus lens 13 is moved by the number of times set in step S520, and the focus adjustment value of each moved position is calculated.

In operation 560, the calculated focus adjustment value is compared to determine that the third calculated focus adjustment value is the point representing the largest value. In operation S570, the controller 40 generates a control signal (for example, a pulse width modulation signal) for moving the focus lens 13 to the position at which the third calculated focus adjustment value is calculated, and inputs it to the driver 50. . Correspondingly, the driving unit 50 adjusts the position of the focus lens 13.

As described above, according to the automatic focusing method and apparatus according to an embodiment of the present invention, by adjusting the position of the focus lens by using the distance measurement to adjust the position of the focus lens relatively faster than the conventional, and focus adjustment By precisely adjusting the position of the focus lens using the value, the position of the focus lens can be precisely adjusted.

In addition, by calculating the distance after applying the algorithm that compensates for the error of the rangefinder output, it is possible to accurately and quickly autofocus control in various environments.

As a result, the response speed between the previews is fast and continuous autofocus control can be performed, and autofocus control can be performed on a display in almost real time. Furthermore, it is possible to improve the speed of automatic focusing by removing the time spent on coarse search. In particular, when near-focus autofocusing is generally improved by more than 50% compared to the current time required.

As described above, the operation and method of adjusting the auto focus of the camera according to an embodiment of the present invention can be made. Meanwhile, in the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Accordingly, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by equivalents of the claims and the claims.

1 is a block diagram showing a schematic configuration of a camera having an automatic focusing function according to an embodiment of the present invention;

2 is a flowchart illustrating a procedure of an autofocus control method according to an embodiment of the present invention;

3 is a diagram illustrating a table for each type according to an embodiment of the present invention;

4 is a curve graph illustrating the relationship between the distance of the type table illustrated in FIG. 3 versus the DMS output voltage (V _d ).

5 is a flowchart showing in detail the sequence of step S200 of FIG.

6 is a view illustrating a positional relationship between a range finder and an image pickup unit included in a camera having an automatic focusing function according to an embodiment of the present invention;

7 is a graph illustrating a relationship between a stroke St of a actuator and a driving voltage V _out in an autofocus control method according to an embodiment of the present invention;

8 is a view illustrating a distance (D) relationship between a subject and a lens and a distance (S) relationship between an initial position and a current position of a focus lens in the autofocus control method according to an embodiment of the present invention;

9 is a flowchart showing the detailed procedure of S500 of FIG. 2;

10 is a graph illustrating a focus adjustment value calculated according to a position of a focus lens in the autofocus control method according to an embodiment of the present invention.

Claims (15)

In the automatic focusing method of the camera, Checking the initial position of the focus lens, Measuring the distance to the subject, Based on the measured distance, determining the displacement that the focus lens should move and moving the focus lens, Measuring a focus adjustment value and adjusting a position of the focus lens to a position representing an optimal focus adjustment value. The method of claim 1, According to each type corresponding to a predetermined condition, further comprising the step of presetting the relationship between the distance and the value indicating the distance to the subject, Measuring the distance to the subject, Measuring a value indicating a distance by using a distance measuring sensor; Applying a value indicating the measured distance to a type corresponding to a current condition, identifying a region to which the value indicating the distance corresponds; Calculating a slope of the area based on a relationship between the distance indicating the distance to the subject and the distance; And calculating a distance to the subject based on the inclination. The method of claim 2, wherein the predetermined condition is a condition that combines photographing information including illumination, reflectance, and color measured by an image signal processor (ISP). The method of claim 3, wherein the predetermined condition is a condition including a combination of temperature information measured by a temperature sensor. The method of claim 3, wherein the shooting information, Autofocusing method characterized in that the distance sensor is information including the illumination, reflectance, and color of the area indicating the distance. The method according to any one of claims 1 to 5, The process of adjusting the position of the focus lens, Measuring a focus adjustment value by moving a predetermined interval, and repeating a predetermined number of times, Moving the focus lens to a position at which the focus adjustment value indicates the highest value. The method of claim 6, And adjusting the position of the focus lens based on the point where the focus lens is moved based on the measured distance. The method of claim 6, And setting a predetermined interval and a predetermined number of times corresponding to the measured distance. In the camera with the auto focus function, A lens assembly comprising a fixed lens and a movable focus lens; An encoder for measuring the position of the focus lens; A driving unit for driving the focus lens; An image sensor which receives a visible light signal of a specific wavelength band reflected from a subject and converts the image into a video signal; An image signal processor (ISP) for processing the image signal received from the image sensor; With a distance meter measuring the distance to the subject, A control unit for adjusting the position of the focus lens in response to the distance measured from the distance meter, calculating a focus adjustment value for different positions, and re-adjusting the position of the focus lens to a position representing an optimal focus adjustment value. Camera with automatic focusing function characterized in that. The method of claim 9, wherein the control unit, According to each type corresponding to a predetermined condition, the relationship between the distance and the value indicating the distance to the subject is set in advance, After applying a value indicating a distance from a range finder to a type corresponding to a current condition, identifying an area to which the value indicating the distance corresponds, and based on the relationship, the slope of the area and the distance to the subject Camera with an automatic focusing function, characterized in that for calculating. The automatic focus control function of claim 10, wherein the predetermined condition is a condition in which photographing information including illumination, reflectance, and color measured by an image signal processor (ISP) is combined. Equipped camera. The method of claim 11, Further comprising a temperature sensor for measuring the temperature information provided to the control unit, The predetermined condition is a camera having an autofocus control function, characterized in that the combination further comprises the temperature information. The method of claim 11, wherein the shooting information, A camera having an autofocus control function, wherein the distance sensor is information including illumination, reflectance, and color of an area indicating a distance. The method according to any one of claims 9 to 13, wherein the control unit, Measuring a focus adjustment value by moving a predetermined interval, it is performed repeatedly a predetermined number of times, and repositioning the focus lens by moving the focus lens to a position where the focus adjustment value indicates the highest value. Camera with automatic focusing function. The method of claim 14, wherein the control unit, And a predetermined interval and a predetermined number of times corresponding to the measured distance.

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