KR20160104236A - Auto focusing image pick-up apparatus, terminal including the same and auto focus controlling method using the same - Google Patents

Abstract

An embodiment provides an automatic focus adjustment imaging apparatus and an automatic focus adjusting method using the same. The automatic focus adjustment imaging apparatus includes: an optical unit including at least one lens; an image sensor unit for converting an optical signal obtained from the optical unit into image information; an image information processing unit for extracting focusing image information from the converted image information; a memory unit for storing an automatic focus (AF) code value; a control unit for detecting the AF code value corresponding to the focusing image information extracted by the image information processing unit to generate a driving signal for moving the optical unit; and a driving unit for adjusting at least one lens position according to the driving signal. The AF code value is updated with an AF code value of a last focusing image, so that a focusing image is rapidly obtained, and a high quality image is obtained by performing accurate focusing adjustment even if the number of use increases or an environment for use changes.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an automatic focus adjustment imaging apparatus, a terminal including the same, and an automatic focus adjustment method using the same. BACKGROUND OF THE INVENTION [0002]

An embodiment of the present invention relates to an automatic focus adjustment imaging apparatus, an automatic focusing method using the same, and a terminal including an auto focus imaging apparatus.

BACKGROUND ART [0002] As the demand for high-quality image acquisition technology in an image pickup apparatus such as a camera grows, the AF (Auto Focus) system is being applied not only to a digital camera, a lens interchangeable camera but also to a camera for a mobile phone or a small mobile device.

The AF system is mainly applied to an AF system of a phase difference detection method or an AF system of a contrast detection method.

The AF system of the contrast detection method is a method of extracting high frequency data from the image data output from the image sensor and performing AF control so that it is maximized. There is no need for a separate sensor or an optical system for contrast AF, and it is possible to construct an AF system at a relatively low cost and obtain an accurate focus. However, a fine focus adjustment method requires relatively long time for focus adjustment .

In addition, the AF system of the phase difference detection system has a configuration in which a pair of images is formed by Pupil Division of light incident through an image pickup lens, and a phase difference, which is an interval between the pair of images formed, The position of the lens is determined and the focus is detected.

In the case of the AF system of the phase difference detection system, there is a case in which the phase difference detection AF sensor is provided separately from the image pickup element, and a method in which the phase difference detection pixel is arranged in the image sensor.

The AF system of the phase difference detection method has an advantage in that it can find the focus fast although the accuracy is lower than that of the contrast AF system.

On the other hand, in order to adjust the focus of the image pickup device, the position of the optical portion included in the image pickup device must be changed, so that the number of times of movement of the optical portion increases with the continuous use of the image pickup device, Aging may occur. As the number of focus adjustment increases, the sensitivity of the positional change of the optical part to be moved may be lowered to obtain an accurate focus image.

In the embodiment, the focus image is acquired using the phase-difference focus adjustment method and the contrast focus adjustment method, and the data extracted from the final focus image obtained through the focus adjustment is updated to the memory unit again, And an automatic focus adjustment method using the same.

An embodiment includes an optical unit including at least one lens; An image sensor unit for converting the optical signal acquired by the optical unit into image information; An image information processor for extracting focus adjustment image information from the converted image information; A memory unit for storing an AF code value; A control unit for detecting the AF code value corresponding to the focus adjustment image information extracted by the image information processing unit and generating a drive signal for moving the optical unit; And a driving unit for adjusting the at least one lens position according to the driving signal. And the AF code value is updated with the AF code value of the final focus image.

The focus adjustment image information may include a phase difference value of the converted image information.

The driving unit may include an actuator module for moving the optical unit in the optical axis direction.

Wherein the control unit comprises: a first AF control unit for controlling the optical unit by a phase difference focus adjustment method; And a second AF control unit for controlling the optical unit by a contrast focus adjustment method; . ≪ / RTI >

Wherein the image sensor section includes: an optical filter layer including a plurality of pixels for imaging; A light shielding mask layer including a first pixel group having a shield region deflected on one side and a second pixel group having a shield region deflected on the other side; And a photodiode layer for converting the optical signal having passed through the optical filter layer and the light-shielding mask layer into an electrical signal; . ≪ / RTI >

The memory unit may be an EEPROM or a flash memory.

According to another embodiment of the present invention, there is provided an optical information recording method comprising the steps of: acquiring optical information by an auto focus adjustment method using an image pickup apparatus of one embodiment; Converting the obtained optical information into an electrical signal; Calculating a phase difference value from the electrical signal; Extracting an AF code value corresponding to the phase difference value; Determining whether a deviation between the extracted AF code value and a reference AF code value is less than or equal to a threshold value; Moving the at least one lens to a focal length position according to at least one of phase-auto-focus adjustment or contrast-auto-focus adjustment corresponding to the extracted AF code value; And updating the final AF code value at the focal distance position to the memory unit; The method includes the steps of:

When the deviation between the extracted AF code value and the reference AF code value is less than or equal to a threshold value, the step of moving the at least one lens to the focal distance position may be a fine focal length adjusting step according to the contrast focal point adjusting method.

Wherein when the deviation between the extracted AF code value and the reference AF code value is larger than a threshold value, moving the at least one lens to a focal length position corresponds to the extracted AF code value according to the phase difference focus adjustment method Moving to a first focal distance; And adjusting a fine focal length from the first focal distance to a second focal distance according to the contrast focal point adjustment method; . ≪ / RTI >

Still another embodiment provides a terminal including the auto focus imaging apparatus of the above-described embodiment.

The automatic focus imaging apparatus and the automatic focus detection method using the same according to the embodiment use the focus adjustment method of the phase difference detection method and the contrast automatic focus adjustment method at the same time and continuously update the AF code value for the lens position of the final focused state The focus value corresponding to the change in the physical properties of the component or the change in the use environment can be obtained at the time of driving the optical portion, and a high-resolution image can be obtained.

1 is a block diagram of an image pickup apparatus according to an embodiment,
2 is a cross-sectional view of the imaging device of one embodiment,
3A is a diagram of a phase difference detection pixel included in the image sensor unit of one embodiment,
FIG. 3B is a diagram illustrating an embodiment of image information generated in the phase difference detection pixel,
4A and 4B are diagrams showing the relationship between the phase difference value and the AF code value,
5 is a flowchart showing a method of adjusting an auto-focus according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

In the description of the embodiment according to the present invention, in the case of being described as being formed "on or under" of each element, the upper (upper) or lower (lower) or under are all such that two elements are in direct contact with each other or one or more other elements are indirectly formed between the two elements. Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

Also, the terms "first" and "second", "upper / upper / upper" and "lower / lower / lower" used in the following description are intended to mean any physical or logical relationship or order May be used solely to distinguish one entity or element from another entity or element, without necessarily requiring or implying that such entity or element is a separate entity or element.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size of each component does not entirely reflect the actual size.

1 is a block diagram showing a configuration of an auto-focus imaging apparatus according to an embodiment.

The automatic focus imaging apparatus of one embodiment may include an optical unit 110, an image sensor unit 130, an image information processing unit 150, a memory unit 160, and a control unit 170.

In addition, the auto-focus imaging apparatus of one embodiment may further include a driving unit 120 that drives the optical unit 110. [

2 is a schematic view showing a cross section of the auto-focus imaging apparatus of one embodiment.

1 and 2, the optical unit 110 may absorb light incident from the outside to output an image to the image sensor unit 130 in order to acquire an image of a subject.

The optical unit 110 may include at least one lens, and the optical signal obtained through at least one lens of the optical unit may be transmitted to the image sensor unit 130.

2, an optical unit 110 included in an embodiment includes a lens unit 10 in which a plurality of lenses 10a, 10b, 10c, and 10d are stacked, And a bobbin 30 for adjusting the position of the lens.

2, a plurality of lenses 10a to 10d are directly fixed to the bobbin 30. However, the lens unit 10 composed of at least one lens is referred to as a separate lens barrel And a lens barrel (not shown) may be arranged to be included in the bobbin 30.

At least one lens 10 fixed to the bobbin 30 is adjusted to change its position in the direction of the optical axis, that is, in the vertical direction in the figure, so that the focus of the image formed from the optical signal obtained by the optical unit 110 can be adjusted have.

At least one lens 10a to 10d included in the optical unit 110 may be a focus lens, a zoom lens, or the like. At least one of the plurality of lenses 10a to 10d included in the optical unit 110 may condense the light to the image sensor unit 130. [

At this time, at least one lens 10a to 10d may draw a large amount of light from one point of the subject and refract the incident light so that the collected light is collected at one point.

The light collected at one point can form a single image, and when the image sensor unit 130 is gathered at one point to form one image, the subject is positioned at the focal length of the lens. Alternatively, when the image obtained by the image sensor unit 130 is formed of two images having a phase difference, the photographed image is focused on the defocused image so as to position the lens at the focal distance. in need.

Although the four lenses 10a to 10d are shown in the drawing, the number of lenses constituting the optical unit 110 is not limited thereto, and a single lens or a plurality of lenses may be disposed in the optical unit 110 .

At least one lens 10a to 10d may be sequentially stacked, and a spacer (not shown) may be disposed between at least one of the lenses 10a to 10d. The spacers can separate the plurality of lenses 10a to 10d from each other and maintain the interval between the lenses 10a to 10d.

The at least one lens 10a to 10d included in the optical unit 110 can be adjusted in position by the driving unit 120. [ That is, the position of the optical unit 110 can be changed by the driving unit 120.

The driving unit 120 may include an actuator module that can adjust the position of at least one lens included in the optical unit 110. The actuator module may be one that performs an AF (Auto Focusing) function in the imaging device.

Referring to FIG. 2, the actuator module may include a voice coil motor (VCM) 121, a magnet 123 interacting with the VCM, and an elastic member 125. At this time, the elastic member 125 may be disposed in connection with the bobbin 30 to which the lens is fixed.

For example, the elastic member 125 may be arranged to connect the optical member 110 with the housing member 115, which is disposed around the optical member 110, and the elastic member 125 is spring- Or ball-based.

The elastic member 125 is elastically moved in a stretched or shrunk manner as the position of the optical unit 110 is changed. On the other hand, as the number of times of use of the auto-focus imaging device is increased and the number of times of focus adjustment is increased, the use of the elastic member connected to the optical unit 110 increases, and the elasticity value of the elastic member, Value can be compared with the value.

The image sensor unit 130 may convert the optical signal input from the optical unit 110 to generate image information. The image information generated by the image sensor unit 130 may be image information of a subject. For example, image information generated upon capturing an image of a subject includes image information of the subject and image information of the photographed subject And focus adjustment image information used for focus adjustment.

The image sensor unit 130 can receive optical information of an object incident through the optical unit 110 and photoelectrically convert the optical information into an electric signal. The image sensor unit 130 may be a CCD (Charge-Coupled Device) sensor or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor.

2, the image sensor unit 130 includes an optical filter layer 133 including a plurality of imaging pixels, a light shielding mask layer (not shown) including a pixel group having a shielding area And a photodiode layer 135 for converting the optical signal having passed through the light filter layer and the light shielding mask layer into an electrical signal.

The light filter layer 133 may include a plurality of pixels for imaging, and the pixels for imaging may be image pixels for generating an image for a subject. Further, the pixel for image pickup of the optical filter layer may be a color pixel.

That is, the pixel for image pickup may be any one of R (Red), G (Green), and B (Blue) pixels and the optical filter layer 133 may have such a shape that such pixels for image pickup are arranged adjacent to each other in a lattice form .

The light shielding mask layer 131 includes a first pixel group having a shield region deflected to one side and a second pixel group deflected to the other side in order to obtain image information used for focus control using a phase-difference auto-focus adjustment method from an optical signal input from the optical unit 110. [ And a second pixel group having a shield region.

3A is a diagram showing a first pixel group 20A and a second pixel group 20B of the embodiment included in the light shielding mask layer.

 In this case, the first pixel group 20A and the second pixel group 20B may be a phase difference detection pixel.

The shield area 20A-1 of the first pixel group and the shield area 20B-1 of the second pixel group may be arranged symmetrically with respect to a vertical line or a horizontal line passing through the center of the pixel.

The light-shielding mask layer 131 may be formed of a metal mask, and the first pixel group and the second pixel group of the light-shielding mask layer 131 may have openings to allow light to enter and shield regions to block light .

If the optical unit 110 is not at the focal distance position during image capturing for the same subject, the optical signal input through the image sensor unit mask layer can generate two pieces of image information.

On the other hand, the two images may be images provided through the mask layer 131 of the image sensor unit. That is, the two images may be images obtained for the optical signal of the subject, which is supplied through the shield area of the mask layer symmetrical to each other, and images obtained by the Pupil Division method for one subject.

3B is a diagram illustrating an example of image information generated through the mask layer of the image sensor unit.

For example, FIG. 3B illustrates image information for an optical signal that has passed through the first pixel group 20A of FIG. 3A, and FIG. 3B represents image information of an optical signal that has passed through the second pixel group 20B of FIG. Lt; / RTI >

Referring to FIG. 3B, the pixel difference d, which is a distance between two points having the same light intensity corresponding to each other, may be a phase difference value.

That is, the phase difference value can be extracted from the defocusing image obtained in the optical unit 110 when the optical unit 110 is not at the focal distance from the subject.

For example, when the image of the subject photographed by the optical unit 110 is obtained by being divided into a pair of phase difference detection images through the image sensor unit 130, the phase difference value is obtained by photographing the same subject It may be a phase difference between two images.

Although not shown in the drawing, in another embodiment of the image sensor unit, the optical filter layer may include a plurality of imaging pixels and a phase difference detection pixel at the same time. That is, the image sensor unit of one embodiment may include an optical filter layer including a plurality of imaging pixels and a phase difference detecting pixel, and a photodiode layer that converts an optical signal passing through the optical filter layer into an electrical signal.

The image information generated from the electrical signal converted by the image sensor unit 130 is converted into phase information from the image information obtained by processing the optical signal passing through the plurality of image pixels and the image information obtained by processing the optical signal passing through the phase difference detection pixel of the mask layer And may include information extracted from the value.

The image information generated by the image sensor unit 130 may be transmitted to the image information processing unit 150.

For example, the image information processing unit 150 generates image information of an image captured from electrical signals of a plurality of imaging pixels supplied from the image sensor unit 130, and based on the electrical signals of the phase difference detection pixels of the optical filter layer The focus adjustment image information can be calculated and extracted.

That is, the image information processing unit 150 may extract the focus adjustment image information for adjusting the focus of the image photographed from the image information transmitted from the image sensor unit 130.

The focus adjustment image information may be a phase difference value extracted from a defocusing image obtained in the optical unit 110 when the optical unit 110 is not at a focal distance from the subject.

The image information processing unit 150 may generate image information from the electrical signal supplied from the image sensor unit 130 and supply the generated information to the image information output unit 190 so as to be output as an image.

In addition, the focus adjustment image information extracted by the image information processing unit 150 may be transmitted to the controller 170. FIG.

For example, the phase difference value calculated by the image information processing unit 150 and extracted as the focus adjustment image information is transmitted to the controller 170. The movement amount of the optical unit 110 corresponding to the extracted phase difference value is stored in a memory unit May be extracted from the data values stored in the storage unit 160 and transferred to the controller 170.

The control unit 170 may generate a driving signal for moving the optical unit 110. [

The generated drive signal may be a stored data value of the memory unit 160 corresponding to the focus adjustment image information supplied from the image information processing unit 150. The generated drive signal may be stored in the memory unit 160 according to the AF code value stored in the memory unit 160 110 < / RTI > to the focal position.

For example, the driving signal generated in the control unit 170 is transmitted to the driving unit 120, and the driving unit 120 can move the optical unit 110 according to the transmitted driving signal. That is, the position of at least one lens included in the optical unit 110 is adjusted according to the driving signal, so that the focus of the image information obtained through the optical unit 110 can be adjusted.

The control unit 170 may include a first AF control unit for controlling the optical unit 110 using a phase difference focus adjustment method and a second AF control unit for controlling the optical unit using a contrast focus adjustment method.

In the imaging apparatus of one embodiment, the focus of the photographed image can be adjusted by at least one of a phase-difference auto-focus adjustment method controlled by the first AF control unit and a contrast auto-focus adjustment method controlled by the second AF control unit.

That is, the above-described two kinds of auto focus adjustment methods may be used at the same time, or at least one auto focus adjustment method may be used, and at least one of the first AF control unit and the second AF control unit may transmit Can be generated.

Meanwhile, the imaging device of one embodiment may include a memory unit 160 that stores AF (Auto Focusing) code values used for focus adjustment.

In the memory unit 160, the reference phase difference value as the focus adjustment image information and the AF code (Auto Focus Code) value matching therewith may be stored in the form of a look-up table.

For example, the AF code value may be a code value indicating the position of the optical portion according to the reference phase difference value. In addition, the AF code value may be a data value for the amount of movement of the optical unit 110 required to obtain the focused image.

That is, when the image captured through the optical unit 110 is an unfocused defocusing image, the phase difference value may be extracted from the defocused image by the image information processing unit 150. [

Next, the AF code value corresponding to the extracted phase difference value is detected by the memory unit 160, the control unit 170 generates a driving signal in accordance with the AF code value detected in the memory unit, The position of the optical unit 110 is adjusted to obtain a focused image (focused image).

The AF code value stored in the memory unit 160 in the automatic focus imaging apparatus of one embodiment may be a value that is updated and stored.

That is, the AF code value stored in the memory unit may be a value that is updated and stored with a changed AF code value after acquiring the final focused image (On Focus Image) by performing auto focus adjustment in the image pickup apparatus.

For example, the AF code value updated and stored may be an AF code value in a final focus image obtained by performing focus adjustment using a phase-difference auto focus method and a contrast auto focus method on an image obtained through the optical portion.

At this time, the updated AF code value may be the AF code value in the case of the phase difference of 0, which is the AF code value at one point corresponding to the focus position. However, the embodiment is not limited to this, and the entire AF code values stored in the memory unit may be updated and stored at a constant rate.

That is, only the amount of change of the AF code value in the case where the reference phase difference value is 0 can be stored in the changed AF code value and stored and stored in the entire AF code value stored in the memory unit.

The memory unit 160 may be an electrically erasable programmable read-only memory (EEPROM) or a flash memory. That is, the stored data value of the memory unit 160 may be converted into a newly updated data value and stored.

4A to 4B show the relationship of the AF code values to the phase difference values.

In FIGS. 4A and 4B, the X-axis represents the AF code value and the Y-axis represents the phase difference value. The graphs of FIGS. 4A and 4B show the phase difference value and the corresponding AF code value.

4A shows the relationship between the phase difference value and the AF code at the beginning of use of the autofocus imaging apparatus. That is, the AF code value of the corresponding point can be found in the graph from the phase difference value calculated and extracted by the image information processing unit, and the control unit calculates the difference between the AF code value and the AF code value when the phase difference value is 0, It is possible to generate a drive signal for moving the optical unit based on the value corresponding to the difference of the AF code.

The driving signal generated by the control unit is transmitted to the driving unit, and the driving unit moves the optical unit according to the transmitted driving signal to obtain a focused image.

FIG. 4B is a diagram illustrating a change in the AF code value according to the number of image acquisitions by the automatic focus adjustment.

Referring to FIG. 4B, graphs (a) and (b) show the relationship of the AF code values to the phase difference values at the beginning of use of the autofocus imaging apparatus. (C) shows the relationship of the AF code value to the phase difference value in the case where the image pickup apparatus is used 10,000 times or more.

As shown in FIG. 4B, as the number of image capturing times in the autofocus imaging apparatus increases, the deviation from the relation between the initial AF code value and the phase difference value increases.

Therefore, since the AF code value initially stored in the memory section of the auto-focus imaging apparatus is based on the initial elasticity value of the elastic member included in the driving section, the change in the elasticity value of the elastic member increases as the number of focus adjustment times of the auto- The optical part may not be moved to the correct focus position according to the initially stored AF code value.

On the other hand, in the case of the automatic focus imaging apparatus of one embodiment, the position of the optical unit in the focus image obtained through the automatic focus adjustment may be sensed, and the AF code value may be calculated from the position of the optical unit to update the memory unit with a new AF code value .

That is, in the automatic focus imaging apparatus of the embodiment, the AF code value stored in the memory unit is updated each time with the AF code value in the final focus image, so that even when the physical properties of the elastic member are changed according to the use frequency, An accurate focus image can be obtained.

In the case of the automatic focus imaging apparatus of the embodiment shown in FIGS. 1 and 2, the focus adjustment image information is extracted from the electrical signal converted by the image sensor unit 130, and the phase difference auto focus adjustment method Contrast auto-focus adjustment method, and the contrast auto-focus adjustment method.

In addition, a new AF code value is extracted from the position of the optical part when acquiring the final focus image, and updated continuously with a new data value in the memory unit, so that accurate auto focus adjustment can be performed irrespective of the use frequency and use environment A high-quality image can be obtained.

Another embodiment may be an automatic focus adjustment method using the autofocus imaging apparatus of the embodiment described above with reference to Figs.

5 is a flowchart showing an auto focus adjustment method according to an embodiment.

Referring to FIG. 5, the automatic focus adjustment method of an embodiment using the auto focus imaging apparatus of the embodiment described above includes a step S1100 of acquiring optical information, a step S1200 of converting the acquired optical information into an electrical signal S1200, (S1300), extracting an AF code value corresponding to the phase difference value (S1400), determining whether a difference between the extracted AF code value and a reference AF code value is equal to or less than a threshold value (S1500 ). Adjusting at least one lens to a focal distance position according to at least one of phase-difference auto-focus adjustment or contrast auto-focus adjustment corresponding to the AF code value.

At this time, adjusting the at least one lens to the focal length position may include performing fine focus adjustment using the contrast auto focus method (S1600).

Step S1600 of fine focus adjustment may be a step of adjusting at least one lens of the optical part to a focal distance position, and at least one lens may be fine-tuned to obtain a new photographed image that is in focus from the optical part .

In the automatic focus adjustment method of one embodiment, the step 1700 of outputting the photographed image after the microfocus adjustment step S1600 may be included.

In addition, the final AF code value of the photographed image after the microfocus adjustment step (S1600) may be updated to the memory unit (S1750).

The step S1500 of determining whether the difference between the extracted AF code value and the reference AF code value is equal to or less than the threshold value may include determining whether the deviation of the AF code value for moving the optical unit to the focal distance position is within a critical range Value or less.

That is, the extracted AF code value may be the AF code value extracted from the memory unit in correspondence with the phase difference value in the photographed image, and the reference AF code value may be an AF code value corresponding to a position where the phase difference value becomes zero, The threshold value may be a deviation range of the AF code value that must be satisfied in order to perform fine focus adjustment.

For example, if it is determined that the deviation between the extracted AF code value and the reference AF code value is less than or equal to the threshold value (S1500), the extracted AF code value is a, the reference AF code value is b, and the threshold value is c , It may be determined whether the absolute value of the difference value between a and b is equal to or less than a threshold value c.

At this time, when the AF code value corresponding to the phase difference value of the photographed image extracted by the image information processing section of the embodiment of the automatic focus imaging apparatus of the embodiment is a and the corresponding reference AF code value at the focal position where the phase difference value is 0 is b have. On the other hand, the threshold value c may be 10 or less.

)가 10이하인 경우 이미지 센서부의 마스크층을 통과하여 얻어진 영상에서 획득된 두 개의 이미지에서 추출된 위상차 값은 위상차 자동 초점 조정 방식에 의하여 초점 조정을 할 수 있는 위상차 값보다 작은 값일 수 있다. For example, the deviation of the AF code value (

) Is 10 or less, the phase difference value extracted from the two images obtained from the image obtained through the mask layer of the image sensor part may be smaller than the phase difference value capable of focusing by the phase difference auto-focus adjustment method.

In other words, in this case, since the phase difference between the acquired two images is not so large, it is difficult to find an accurate focus position when the focus is adjusted by the phase difference autofocus method, so that the accurate focus position can not be adjusted only by the phase difference auto focus adjustment method.

일 때 적어도 하나의 렌즈를 초점 거리 위치로 조정하는 단계는 컨트라스트 자동 초점 조정 방식에 따라 미세 초점 조절하는 단계일 수 있다.When the difference of the AF code values is judged to be equal to or less than the threshold value, that is,

The step of adjusting at least one lens to the focal distance position may be a step of adjusting the microfocus according to the contrast auto focus adjustment method.

일 때, 적어도 하나의 렌즈를 초점 거리 위치로 조정하는 단계는 위상차 자동 초점 조정 방식에 따라 AF 코드값의 차이가 임계값 이하가 되는 제1 초점 위치로 광학부를 이동시키는 단계와 컨트라스트 자동 초점 조정 방식에 따라 제1 초점 위치에서 제2 초점 위치로 미세 초점 조절하는 단계를 포함할 수 있다.If it is determined that the difference between the AF code values is larger than the threshold value, that is,

, The step of adjusting at least one lens to a focal length position includes moving the optical part to a first focus position where the difference of the AF code value is equal to or less than a threshold value according to the phase difference auto focus adjustment method, Adjusting the microfocus from the first focus position to the second focus position according to the first focus position.

That is, in the automatic focus adjustment method of the embodiment, the phase difference value, which is the shift amount of the focus, is extracted by the phase difference automatic focus adjustment method, and the AF code value corresponding thereto is extracted to find the lens of the optical part at the first focus position, And moving the lens of the optical unit to the second focus position, which is an accurate focus position, through fine focus adjustment by a contrast auto focus adjustment method.

On the other hand, when the difference between the AF code value and the reference AF code value at the extracted phase difference value is equal to or less than the threshold value, only the focus adjustment step using the contrast auto focus adjustment method may be included. At this time, May be an exact focus position with a phase difference value of zero.

The AF code value at the final position moved after the optical part is moved by fine focus adjustment can be updated to a new AF code value when the phase difference value is 0 and stored in the memory part.

Therefore, in the case of the automatic focus adjustment method according to the embodiment, the AF code value at the final focal length position in the focused state is continuously updated in the memory unit, and the AF code value is stored in the memory unit regardless of the state change of the driving unit of the auto focus apparatus It is possible to improve the focus accuracy, and by using the phase difference auto focus method and the contrast auto focus method simultaneously, it is possible to find the accurate focus in a short time by performing the auto focus adjustment.

Hereinafter, an embodiment of a terminal including the above-described auto focus imaging apparatus will be described, but the embodiments are not limited thereto.

The terminal can place the automatic focus imaging apparatus of the embodiment on the front side or on the rear side.

For example, the terminal including the auto focus imaging apparatus of the embodiment may be a portable terminal, but the embodiment is not limited thereto, and the auto focus imaging apparatus of the above-described embodiment can be also provided in a fixed terminal.

An image of a subject obtained in the auto-focus imaging apparatus of the terminal can be displayed on the display unit of the portable terminal.

The display unit may be a device for displaying the acquired image so that the user can confirm the image, and may be disposed on the front surface of the portable terminal. The display unit may include, but is not limited to, an LCD (Liquid Crystal Display), an OLED (Organic Light Emitting Diode), and the like.

In addition, the image obtained by using the auto focus image pickup apparatus of the embodiment can be provided to be used for other functions of the portable terminal.

On the other hand, in the case of the memory unit included in the auto-focus imaging apparatus of the embodiment, a part of the memory of the portable terminal may replace the memory. For example, the AF code value may be stored in the memory of the portable terminal.

The portable terminal of the embodiment can accurately and easily adjust the focus by using the phase difference focus adjustment method and the contrast focus adjustment method by including the automatic focus imaging apparatus of one embodiment, It is possible to obtain a high-quality image by correcting the focus even when the image is changed.

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 embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

100: Image pickup device 110: Optical part
120: driving unit 130: image sensor unit

Claims (10)

An optical portion including at least one lens;
An image sensor unit for converting the optical signal acquired by the optical unit into image information;
An image information processor for extracting focus adjustment image information from the converted image information;
A memory unit for storing an AF code value;
A control unit for detecting the AF code value corresponding to the focus adjustment image information extracted by the image information processing unit and generating a drive signal for moving the optical unit; And
A driving unit for adjusting the at least one lens position according to the driving signal; Lt; / RTI >
Wherein the AF code value is updated with the AF code value of the final focus image. 2. The autofocus imaging apparatus of claim 1, wherein the focus adjustment image information includes a phase difference value of the converted image information. The autofocus imaging apparatus according to claim 1, wherein the driving section includes an actuator module for moving the optical section in the optical axis direction. The apparatus of claim 1, wherein the control unit
A first AF control unit for controlling the optical unit by a phase difference focus adjustment method; And
A second AF control unit for controlling the optical unit by a contrast focus adjustment method; And an image pickup device. The image pickup apparatus according to claim 1,
An optical filter layer including a plurality of pixels for imaging;
A light shielding mask layer including a first pixel group having a shield region deflected on one side and a second pixel group having a shield region deflected on the other side; And
A photodiode layer for converting the optical signal having passed through the optical filter layer and the light-shielding mask layer into an electrical signal; And an image sensor. The autofocus imaging apparatus according to claim 1, wherein the memory unit is an EEPROM or a flash memory. An automatic focusing method using the automatic focusing device according to any one of claims 1 to 6,
Obtaining optical information;
Converting the obtained optical information into an electrical signal;
Calculating a phase difference value from the electrical signal;
Extracting an AF code value corresponding to the phase difference value;
Determining whether a deviation between the extracted AF code value and a reference AF code value is less than or equal to a threshold value;
Moving the at least one lens to a focal length position according to at least one of phase-auto-focus adjustment or contrast-auto-focus adjustment corresponding to the extracted AF code value; And
Updating the final AF code value at the focal distance position to the memory unit; And an auto-focusing method. 8. The method of claim 7, wherein when the deviation between the extracted AF code value and the reference AF code value is less than or equal to a threshold value,
The step of moving the at least one lens to a focal distance position
And adjusting the fine focal length according to the contrast focal point adjustment method. 8. The method of claim 7, wherein if the deviation between the extracted AF code value and the reference AF code value is greater than a threshold value,
The step of moving the at least one lens to a focal distance position
Moving to a first focal distance corresponding to the extracted AF code value according to the phase difference focus adjustment method; And
Adjusting a fine focal length from the first focal distance to a second focal distance according to the contrast focal point adjustment method; And an auto-focusing method. A terminal comprising the auto-focus imaging device according to any one of claims 1 to 6.

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