Image pickup apparatus including lens elements having different diameters

An image pickup apparatus capable of performing a zooming function without increasing a thickness of the image pickup apparatus, and obtaining depth information at the same time by using lens elements having different diameters, is provided. The image pickup apparatus includes lens elements, and image pickup regions respectively disposed in correspondence to the lens elements. At least two of the lens elements have different diameters. At least two of the image pickup regions have different sizes. A smallest image pickup region among the image pickup regions having a smallest size among sizes of the image pickup regions is disposed with respect to a lens element among the lens elements having a largest diameter. A largest image pickup region among the image pickup regions having a largest size among sizes of the image pickup regions is disposed with respect to a lens element among the lens elements having a smallest diameter.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No. 10-2014-0048873, filed on Apr. 23, 2014, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

Apparatuses consistent with exemplary embodiments relate to an image pickup apparatus including lens elements having different diameters.

2. Description of Related Art

Because thicknesses of mobile devices, such as mobile phones, are being continuously reduced, there is a demand to reduce thicknesses of optical systems of cameras disposed in mobile devices. When a thickness of an optical system is reduced, a focal length of the optical system is reduced, and thus a size of an image sensor is reduced. As a result, quality of an image picked up via the optical system may be deteriorated. The reason for the deterioration is that a number of pixels decreases as the size of an image is reduced. However, if a size of pixels of an image sensor is reduced in correspondence to the size reduction of the image sensor, images having sufficiently high resolutions may be obtained. Therefore, various attempts are being made to reduce pixel pitch of an image sensor. For example, a pixel pitch of current image sensors has been reduced to about 1 μm.

Meanwhile, because a thickness of a camera in a mobile device is limited, a unifocal lens with a short focal length is generally employed instead of a zoom lens with variable focal lengths. Therefore, it may be difficult for a camera of a mobile device to provide a zooming function. Most cameras in mobile devices provide a digital zooming function instead of an optical zooming function. In other words, because digital zoom is a function for magnifying a portion of an original image picked up by a camera merely via signal processing, quality of a magnified image may be deteriorated as an angle of view of the magnified image is narrowed.

SUMMARY

Exemplary embodiments address at least the above problems and/or disadvantages and other disadvantages not described above. Also, the exemplary embodiments are not required to overcome the disadvantages described above, and an exemplary embodiment may not overcome any of the problems described above.

According to an aspect of an exemplary embodiment, there is provided an image pickup apparatus including lens elements, and image pickup regions respectively disposed in correspondence to the lens elements. At least two of the lens elements have different diameters, and at least two of the image pickup regions have different sizes. A smallest image pickup region among the image pickup regions having a smallest size among sizes of the image pickup regions is disposed with respect to a lens element among the lens elements having a largest diameter, and a largest image pickup region among the image pickup regions having a largest size among sizes of the image pickup regions is disposed with respect to a lens element among the lens elements having a smallest diameter.

The image pickup regions may include image sensors that are physically separated from each other.

At least two of the image pickup regions may have different pixel pitches, and a pixel pitch of an image pickup region among the image pickup regions may decrease as a diameter of a respective lens element among the lens elements increases.

The image pickup regions may be logically divided regions in a single image sensor.

The at least two of the lens elements may be configured to form light spots having different sizes on the respective image pickup regions.

The image pickup apparatus may be configured to extract depth information from images obtained via the lens elements and the respective image pickup regions.

The at least two of the lens elements may include a first lens element having a first diameter, a second lens element having a second diameter larger than the first diameter, and a third lens element having a third diameter larger than the second diameter. The at least two of the image pickup regions may include a first image pickup region corresponding to the first lens element and having a first size, a second image pickup region corresponding to the second lens element and having the first size, and a third image pickup region corresponding to the third lens element and having a second size smaller than the first size. The first image pickup region may have a first pixel pitch, a second image pickup region may have a second pixel pitch smaller than the first pixel pitch, and a third image pickup region may have a third pixel pitch smaller than the second pixel pitch.

The at least two of the lens elements may include a first lens element having a first diameter, a second lens element having the first diameter, and a third lens element having a second diameter larger than the first diameter. The at least two of the image pickup regions may include a first image pickup region corresponding to the first lens element and having a first size, a second image pickup region corresponding to the second lens element and having the first size, and a third image pickup region corresponding to the third lens element and having a second size smaller than the first size. The first and second image pickup regions may have a first pixel pitch, and a third image pickup region may have a second pixel pitch smaller than the first pixel pitch.

The first through third lens elements may be linearly disposed in a horizontal direction when viewed from a front or rear of the image pickup apparatus, the first lens element may be disposed between the second lens element and the third lens element, and the first image pickup region may be disposed between the second image pickup region and the third image pickup region.

The first through third lens elements may be linearly disposed in a horizontal direction when viewed from a front or rear of the image pickup apparatus, the third lens element may be disposed between the first lens element and the second lens element, and the third image pickup region may be disposed between the first image pickup region and the second image pickup region.

The at least two of the lens elements may include a first lens element having a first diameter, a second lens element having a second diameter larger than the first diameter, a third lens element having the second diameter, a fourth lens element having a third diameter larger than the second diameter, and a fifth lens element having the third diameter.

The at least two of the image pickup regions may include a first image pickup region corresponding to the first lens element and having a first size, a second image pickup region corresponding to the second lens element and having the first size, a third image pickup region corresponding to the third lens element and having the first size, a fourth image pickup region corresponding to the fourth lens element and having a second size smaller than the first size, and a fifth image pickup region corresponding to the fifth lens element and having the second size. The first image pickup region may have a first pixel pitch, the second and third image pickup regions may have a second pixel pitch smaller than the first pixel pitch, and the fourth and fifth image pickup regions may have a third pixel pitch smaller than the second pixel pitch.

The first through fifth lens elements may be linearly disposed in a horizontal direction when viewed from a front or rear of the image pickup apparatus. The first lens element may be disposed between the second lens element and the third lens element, the second lens element may be disposed between the first lens element and the fourth lens element, and the third lens element may be disposed between the first lens element and the fifth lens element.

The at least two of the lens elements may include a first lens element having a first diameter, second through fifth lens elements having a second diameter larger than the first diameter, and sixth through ninth lens elements having a third diameter larger than the second diameter. The at least two of the image pickup regions may include first through fifth image pickup regions corresponding to the first through fifth lens elements and having a first size, and sixth through ninth image pickup regions corresponding to the sixth through ninth lens elements and have a second size smaller than the first size.

The sixth through ninth lens elements may be respectively disposed on four vertices of a quadrangle on a surface of the image pickup apparatus, the second through fifth lens elements may be respectively disposed at centers of four sides of the quadrangle, and the first lens element may be disposed in a center of the quadrangle.

The at least two of the lens elements may include first through third lens elements having a first diameter, and fourth and fifth lens elements having a second diameter larger than the first diameter.

The first through third lens elements may be linearly disposed in a first direction when viewed from a front or rear of the image pickup apparatus, and the fourth and fifth lens elements may be linearly disposed in a second direction perpendicular to the first direction.

According to an aspect of another exemplary embodiment image pickup apparatus including a first lens element having a first diameter, a second lens element having a second diameter larger than the first diameter; a first image pickup region of a first size disposed in correspondence to the first lens element, and a second image pickup region of a second size smaller than the first size disposed in correspondence to the second lens element.

The first image pickup region may have a first pixel pitch, and the second image pickup region may have a second pixel pitch smaller than the first pixel pitch.

The image pickup apparatus may further include a third lens element having a third diameter larger than the first diameter and smaller than the second diameter, and a third image pickup region of the first size disposed in correspondence to the third lens element, the third image pickup region having a third pixel pitch smaller than the first pixel pitch and larger than the second pixel pitch.

The image pickup apparatus may further include a third lens element having the first diameter; and a third image pickup region of the first size disposed in correspondence to the third lens element, the third image pickup region having the first pixel pitch.

DETAILED DESCRIPTION

FIG. 1Ais a schematic diagram showing a structure of an image pickup apparatus100according to an exemplary embodiment. For example, the image pickup apparatus100may be a mobile device, such as a mobile phone, a tablet personal computer (PC), or a laptop PC. Referring toFIG. 1A, the image pickup apparatus100includes a first lens element101, a second lens element102, and a third lens element103having different diameters. In this example, the first lens element101has a first diameter, which is the smallest diameter, the second lens element102has a second diameter, which is larger than the first diameter, and the third lens element103has a third diameter, which is larger than the second diameter. Furthermore, the first through third lens elements101,102, and103are linearly disposed in a horizontal direction, when viewed from a rear, front, or surface of the image pickup apparatus100. In this example, the third lens element103is disposed on the left, the first lens element101is disposed in the center, and the second lens element102is disposed on the right.

FIG. 1Bis a schematic cross-sectional diagram showing an arrangement of the first through third lens elements101,102, and103and first through third image pickup regions111,112, and113of the image pickup apparatus100shown inFIG. 1A. Referring toFIG. 1B, the first through third image pickup regions111,112, and113respectively corresponding to the first through third lens elements101,102, and103are disposed. For example, the first image pickup region111is disposed on a focal plane of the first lens element101, the second image pickup region112is disposed on a focal plane of the second lens element102, and the third image pickup region113is disposed on a focal plane of the third lens element103. Therefore, the first through third image pickup regions111,112, and113form images by using light beams focused by the first through third lens elements101,102, and103respectively corresponding thereto. The first through third image pickup regions111,112, and113may include separate image sensors that are physically separated from one another, respectively. An image sensor may be a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor.

The first through third lens elements101,102, and103may have the same focal length. Alternatively, as long as an internal space of the image pickup apparatus100allows, the first through third lens elements101,102, and103may have focal lengths that are different from one another. However, because differences between focal lengths may be insignificant due to a narrow space inside the image pickup apparatus100, brightnesses of the first through third lens elements101,102, and103may be determined based on diameters of the first through third lens elements101,102, and103. For example, an F number of the first lens element101with the smallest diameter may be 2.2, an F number of the second lens element102may be 1.5, and an F number of the third lens element103with the largest diameter may be 1.0. A theoretical size of a light spot focused by a lens element may be determined based on an F number of the lens element. In detail, as the F number of the lens element decreases (that is, as a brightness of the lens element increases), the size of the light spot may decrease. Therefore, a size of a light spot formed by the third lens element103with the smallest F number may be the smallest.

FIG. 1Cis a diagram showing sizes and pixel pitches of the first through third image pickup regions111,112, and113of the image pickup apparatus100shown inFIG. 1A. Referring toFIG. 1C, the sizes of the first through third image pickup regions111,112, and113may be different from one another. In this example, the first and second image pickup regions111and112have the same first size, whereas the third image pickup region113has a second size smaller than the first size. As described above, because the focal lengths of the first through third lens elements101,102, and103are identical or similar to one another, angles of view are determined based on the sizes of the image pickup regions111,112, and113. In this example, images obtained via the first and second image pickup regions111and112have the same first angle of view, whereas an image obtained via the third image pickup region113has a second angle of view narrower than the first angle of view. Therefore, the third image pickup region113provides a relative telescopic zoom, compared to the first and second image pickup regions111and112. In other words, the first and second image pickup regions111and112provide a first zoom corresponding to a relatively wide angle of view, whereas the third image pickup region113provides a second zoom corresponding to a relatively telescopic angle of view. Therefore, the image pickup apparatus100provides a zoom function including the first zoom (wide angle) and the second zoom (telescopic angle).

Furthermore,FIG. 1Cshows pixels121,122, and123, which are respectively same-sized portions of the first through third image pickup regions111,112, and113magnified at the same magnification. As shown inFIG. 1C, the first through third image pickup regions111,112, and113have different pixel pitches from one another. In this example, the first image pickup region111has a first pixel pitch, the second image pickup region112has a second pixel pitch smaller than the first pixel pitch, and the third image pickup region113has a third pixel pitch smaller than the second pixel pitch. In other words, as the F numbers (or diameters) of the lens elements101,102, and103respectively corresponding to the image pickup regions111,112, and113increase, the pixel pitches of the image pickup regions111,112, and113decrease. Furthermore, as the F numbers (or diameters) of the lens elements101,102, and103respectively corresponding to the image pickup regions111,112, and113decrease, the pixel pitches of the image pickup regions111,112, and113increase. For example, the first pixel pitch of the first image pickup region111corresponding to the first lens element101having the largest F number is the largest, whereas the third pixel pitch of the third image pickup region113corresponding to the third lens element103having the smallest F number is the smallest.

A resolution of an image may be proportional to a modulation transfer function (MTF) of an optical system and frequency response characteristics of pixels, in which the MTF increases as an F number of an optical system decreases. Therefore, the resolution of the image may be improved by reducing the F number of the optical system. However, even if a size of a light spot is reduced, if a pixel pitch is too large, the response characteristics of pixels may be deteriorated, and thus the image resolution may not be improved. Therefore, the image resolution may be improved when the pixel pitch is reduced in correspondence to the reduction of the light spot.

According to the exemplary embodiment, the light spot formed by the third lens element103having the smallest F number may have the smallest size, whereas a light spot formed by the first lens element101having the largest F number may have the largest size. Furthermore, the first image pickup region111corresponding to the first lens element101having the largest F number has the largest pixel pitch, whereas the third image pickup region113corresponding to the third lens element103having the smallest F number has the smallest pixel pitch. As a result, an image formed by the third lens element103and the third image pickup region113may have the highest resolution, whereas an image formed by the first lens element101and the first image pickup region111may have the lowest resolution. As described above, the third lens element103and the third image pickup region113function as telescopic zoom. Therefore, a quality of an image with a narrow angle of view may be improved by improving a resolution of the image formed by the third lens element103and the third image pickup region113. Therefore, the image pickup apparatus100may provide the zoom function that does not cause image quality deterioration when switching between a wide angle zoom and a telescopic zoom, without an optical system having variable focal lengths.

Meanwhile, because the first and second image pickup regions111and112have the same size, first and second images respectively obtained via the first and second image pickup regions111and112have the same angle of view, and a parallax effect is obtained due to a difference between locations of the first and second lens elements101and102. Therefore, the image pickup apparatus100may extract depth information by using the first and second images having the same angle of view and the parallax effect. In other words, a set of the first lens element101and the first image pickup region111and a set of the second lens element102and the second image pickup region112may function as a stereoscopic camera. Furthermore, more precise depth information may be extracted by using a high resolution third image obtained via the third image pickup region113. For example, because centers of first and second images may correspond to the third image with a narrow angle of view, depth information for a center angle of view may be extracted by using a center portion of the second image, which has a higher resolution than the first image, and the third image, whereas depth information for a peripheral angle of view may be extracted by using a peripheral portion of the first image and a peripheral portion of the second image.

Furthermore, because the second image has the same angle of view as the first image and has a higher resolution than the first image, the image pickup apparatus100may select and display the second image to display an image of the first zoom to a user. On the other hand, because the third image has a higher resolution than the second image and has a narrower angle of view than the second image, the image pickup apparatus100may replace the center portion of the second image, which corresponds to the third image, with the third image, and display the modified image to a user as the image of the first zoom. Furthermore, the image pickup apparatus100may provide a digital zoom between the first zoom and the second zoom via signal processing. Here, to provide a smooth digital zoom between the first zoom and the second zoom, the second image and the third image having relatively high resolutions may be used.

As described above, the image pickup apparatus100may simultaneously obtain a plurality of images with different angles of view. Therefore, an optical zoom function may be embodied without increasing a thickness of the image pickup apparatus100. Furthermore, a high resolution may be obtained with respect to an image having a narrow angle of view.

Although it is described above that the image pickup apparatus100includes the three lens elements101,102, and103and the three image pickup regions111,112, and113in the exemplary embodiments shown inFIGS. 1A through 1C, it is merely an example, and an inventive concept is not limited thereto. For example, two lens elements and two image pickup regions, or four or more lens elements and four or more image pickup regions, may be disposed in various ways. Furthermore, diameters of lens elements, sizes of image pickup regions, and pixel pitches of the image pickup regions may vary as an occasion demands. Although various exemplary embodiments are described below, the inventive concept is not limited to the exemplary embodiments described below.

FIG. 2Ais a schematic diagram showing a structure of an image pickup apparatus200according to another exemplary embodiment,FIG. 2Bis a schematic diagram showing an arrangement of first through third lens elements201,202, and203and first through third image pickup regions211,212, and213of the image pickup apparatus200shown inFIG. 2A, andFIG. 2Cis a diagram showing sizes and pixel pitches of the first through third image pickup regions211,212, and213of the image pickup apparatus200shown inFIG. 2A.

Referring toFIG. 2A, the image pickup apparatus200includes the first lens element201having a first diameter, the second lens element202having the first diameter, and the third lens element203having a second diameter. In other words, the first and second lens elements201and202have the same diameter, whereas the third lens element203has a diameter larger than that of the first and second lens elements201and202. Therefore, because the third lens element203has the smallest F number, a light spot formed by the third lens element203has the smallest size. Furthermore, the first through third lens elements201,202, and203are linearly disposed in a horizontal direction, when viewed from a rear, front, or surface of the image pickup apparatus200. In this example, the third lens element203is disposed on the left, the first lens element201is disposed in the center, and the second lens element202is disposed on the right.

Referring toFIGS. 2B and 2C, the first through third image pickup regions211,212, and213respectively corresponding to the first through third lens elements201,202, and203are disposed. The first through third image pickup regions211,212, and213may include separate image sensors that are physically separated from one another, respectively. In this example, the first and second image pickup regions211and212have the same first size, whereas the third image pickup region213has a second size smaller than the first size. Therefore, images obtained via the first and second image pickup regions211and212have the same first angle of view, whereas an image obtained via the third image pickup region213has a second angle of view narrower than the first angle of view.

Furthermore, referring to pixels221,222, and223shown inFIG. 2C, the first and second image pickup regions211and212have the same first pixel pitch, whereas the third image pickup region213has a second pixel pitch smaller than the first pixel pitch. Therefore, the images obtained via the first and second image pickup regions211and212have lower resolutions than the image obtained via the third image pickup region213. However, resolutions of the images obtained via the first and second image pickup regions211and212may be improved by using a resolution improving technique, e.g., super resolution. For example, a single image with improved resolution may be generated by synthesizing two images respectively obtained via the first and second image pickup regions211and212. By using the super resolution technique, an image may be smoothly processed when a digital zoom function for generating an image having an angle of view between a first angle of view and a second angle of view is performed. Other operations and functions of the image pickup apparatus200may be identical to those described above with reference toFIGS. 1A through 1C.

FIG. 3Ais a schematic diagram showing a structure of an image pickup apparatus300according to another exemplary embodiment,FIG. 3Bis a schematic cross-sectional diagram showing an arrangement of first through third lens elements301,302, and303and first through third image pickup regions311,312, and313of the image pickup apparatus300shown inFIG. 3A, andFIG. 3Cis a diagram showing sizes and pixel pitches of the first through third image pickup regions311,312, and313of the image pickup apparatus300shown inFIG. 3A.

Referring toFIG. 3A, the image pickup apparatus300includes a first lens element301having a first diameter, a second lens element302having the first diameter, and a third lens element303having a second diameter. In other words, the first and second lens elements301and302have the same diameter, whereas the third lens element303has a diameter larger than that of the first and second lens elements301and302. Therefore, because the third lens element303has the smallest F number, a light spot formed by the third lens element303has the smallest size. Furthermore, the first through third lens elements301,302, and303are linearly disposed in a horizontal direction, when viewed from a rear, front, or surface of the image pickup apparatus300. In this example, the first lens element301is disposed on the left, the third lens element303is disposed in the center, and the second lens element302is disposed on the right.

Referring toFIGS. 3B and 3C, the first through third image pickup regions311,312, and313respectively corresponding to the first through third lens elements301,302, and303are disposed. The first through third image pickup regions311,312, and313may have different sizes and pixel pitches from one another. In this example, the first and second pickup regions311and312have the same first size, whereas the third image pickup region313has a second size smaller than the first size. Therefore, images obtained via the first and second image pickup regions311and312have the same first angle of view, whereas an image obtained via the third image pickup region313has a second angle of view narrower than the first angle of view. Furthermore, referring to pixels321,322, and323shown inFIG. 3C, the first and second image pickup regions311and312have the same first pixel pitch, whereas the third image pickup region313has a second pixel pitch smaller than the first pixel pitch. Therefore, the image obtained via the third image pickup region313has a higher resolution than the images obtained via the first and second image pickup regions311and312.

The image pickup apparatus300shown inFIG. 3Ahas a structure similar to the structure of the image pickup apparatus200shown inFIG. 2A, in which locations of the first through third lens elements301,302, and303and locations of the first through third image pickup regions311,312, and313of the image pickup apparatus300are different from locations of the first through third lens elements201,202, and203and locations of the first through third image pickup regions211,212, and213of the image pickup apparatus200. For example, the third lens element303is disposed at the center, and the first lens element301and the second lens element302are disposed at either side of the third lens element303. Therefore, a distance between the first lens element301and the second lens element302is larger compared to the exemplary embodiment shown inFIG. 2A, and thus parallax may increase. As a result, resolution and precision of depth information may be improved.

FIG. 4Ais a schematic diagram showing a structure of an image pickup apparatus400according to another exemplary embodiment,FIG. 4Bis a schematic cross-sectional diagram showing an arrangement of first through third lens elements401,402, and403and first through third image pickup regions411,412, and413of the image pickup apparatus400shown inFIG. 4A, andFIG. 4Cis a diagram showing sizes of the first through third image pickup regions411,412, and413of the image pickup apparatus400shown inFIG. 4A.

Referring toFIG. 4A, the image pickup apparatus400includes the first lens element401having a first diameter, the second lens element402having the first diameter, and the third lens element403having a second diameter. In other words, the first and second lens elements401and402have the same diameter, whereas the third lens element403has a diameter larger than that of the first and second lens elements401and402. Therefore, because the third lens element403has the smallest F number, a light spot formed by the third lens element403has the smallest size. Furthermore, the first through third lens elements401,402, and403are linearly disposed in a horizontal direction, when viewed from a rear, front, or surface of the image pickup apparatus400. In this example, the first lens element401is disposed on the left, the third lens element403is disposed in the center, and the second lens element402is disposed on the right.

Referring toFIGS. 4B and 4C, the first through third image pickup regions411,412, and413respectively corresponding to the first through third lens elements401,402, and403are disposed. Here, the first through third image pickup regions411,412, and413are logically divided regions in a single image sensor410. For example, as shown inFIG. 4C, in the single image sensor410, the first image pickup region411is a region divided to detect a light beam focused by the first lens element401, the second image pickup region412is a region divided to detect a light beam focused by the second lens element402, and the third image pickup region413is a region divided to detect a light beam focused by the third lens element403. In this case, the first through third image pickup regions411,412, and413may have the same pixel pitch.

The first through third image pickup regions411,412, and413may have different sizes from one another. In this example, the first and second image pickup regions411and412have the same first size, whereas the third image pickup region413has a second size smaller than the first size. To this end, an image processing unit of the image pickup apparatus400may split pixels in the image sensor410into the first through third image pickup regions411,412, and413and a dummy region, based on preset coordinates. Furthermore, the image processing unit may generate a first image by using only signals generated by the first image pickup region411, generate a second image by using only signals generated by the second image pickup region412, generate a third image by using only signals generated by the third image pickup region413, and ignore signals generated by the dummy region.

According to the exemplary embodiment, because the single image sensor410is used for the first through third lens elements401,402, and403, instead of using separate image sensors, an assembly process may be simplified, and fabrication costs may be reduced. The structure of the single image sensor410described above with reference toFIGS. 4A through 4Cmay also be applied to other exemplary embodiments.

FIG. 5Ais a schematic diagram showing a structure of an image pickup apparatus500according to another exemplary embodiment,FIG. 5Bis a schematic cross-sectional diagram showing an arrangement of first through fifth lens elements501,502,503,504, and505and first through fifth image pickup regions511,512,513,514, and515of the image pickup apparatus500shown inFIG. 5A, andFIG. 5Cis a diagram showing sizes and pixel pitches of the first through fifth image pickup regions511,512,513,514, and515of the image pickup apparatus500shown inFIG. 5A.

Referring toFIG. 5A, the image pickup apparatus500includes a first lens element501having a first diameter, a second lens element502having a second diameter larger than the first diameter, a third lens element503having the second diameter, a fourth lens element504having a third diameter larger than the second diameter, and a fifth lens element505having the third diameter. In other words, the first lens element501has a smallest diameter. Furthermore, the second and third lens elements502and503have a diameter larger than that of the first lens element501, and the fourth and fifth lens elements504and505have the largest diameter. Therefore, the first lens element501has the largest F number, whereas the fourth and fifth lens elements504and505have the smallest F number. The first through fifth lens elements501,502,503,504, and505are linearly disposed in a horizontal direction, when viewed from a rear, front, or surface of the image pickup apparatus500. In this example, the first lens element501is disposed at the center, the second and third lens elements502and503are disposed at either side of the first lens element501, and the fourth and fifth lens elements504and505are disposed to be at the left end and the right end, respectively.

Referring toFIGS. 5B and 5C, the first through fifth image pickup regions511,512,513,514, and515respectively corresponding to the first through fifth lens elements501,502,503,504, and505are disposed. The first through fifth image pickup regions511,512,513,514, and515may have different sizes and pixel pitches from one another. In this example, the first through third image pickup regions511,512, and513have the same first size, whereas the fourth and fifth image pickup regions514and515have a second size smaller than the first size. Therefore, images obtained via the first through third image pickup regions511,512, and513have the same first angle of view, whereas images obtained via the fourth and fifth image pickup regions514and515have a second angle of view narrower than the first angle of view.

Furthermore, referring to pixels521,522,523,524, and525shown inFIG. 5C, the first image pickup region511has a first pixel pitch, the second and third image pickup regions512and513have a second pixel pitch smaller than the first pixel pitch, and the fourth and fifth image pickup regions514and515have a third pixel pitch smaller than the second pixel pitch. Therefore, the images obtained via the second and third image pickup regions512and513have higher resolutions than the image obtained via the first image pickup region511, and the images obtained via the fourth and fifth image pickup regions514and515have higher resolutions than the images obtained via the second and third image pickup regions512and513.

In the above-stated structure, an image having a first angle of view may be provided via the first lens element501and the first image pickup region511, images having the first angle of view may be provided via the second and third lens elements502and503and the second and third image pickup regions512and513, and images having a second angle of view may be provided via the fourth and fifth lens elements504and505and the fourth and fifth image pickup regions514and515. Furthermore, depth information of an image having the first angle of view may be extracted by using two images respectively obtained via the second and third lens elements502and503and the second and third image pickup regions512and513, and depth information of an image having the second angle of view may be extracted by using two images respectively obtained via the fourth and fifth lens elements504and505and the fourth and fifth image pickup regions514and515.

Because precision of depth information may be deteriorated as a distance between the image pickup apparatus500and an object increases, the fourth and fifth lens elements504and505providing a telescopic zoom are disposed at outermost locations, such that a distance between the fourth and fifth lens elements504and505is the largest. As a result, parallax between the two images obtained via the fourth and fifth lens elements504and505may increase, and thus the deterioration of the precision of the depth information may be compensated.

Furthermore, because the image obtained via the first image pickup region511and the images obtained via the second and third image pickup regions512and513have the same angle of view, depth information extracted via the second and third image pickup regions512and513may be applied to the image obtained via the first image pickup region511. Alternatively, depth information may be extracted by using all of the three images extracted via the first through third image pickup regions511,512, and513. Alternatively, depth information may be extracted by using the image obtained via the first image pickup region511and the image obtained via the second image pickup region512and, at the same time, depth information may be extracted by using the image obtained via the second image pickup region512and the image obtained via the third image pickup region513.

In the image pickup apparatus500shown inFIGS. 5A through 5C, some components may be omitted or modified as an occasion demands. For example, the second and third lens elements502and503and the second and third image pickup regions512and513may be removed, or the fourth and fifth lens elements504and505and the fourth and fifth image pickup regions514and515may be removed. In this case, the image pickup apparatus500may include three lens elements and three image pickup regions that are symmetrically disposed. Here, for convenience of depth information extraction, the three image pickup regions may have the same size. Alternatively, the first through third image pickup regions511,512, and513may have the same pixel pitch, and the first through third lens elements501,502, and503may have the same diameter. As a result, resolution of an image may be improved by using a resolution improving technique like the super resolution, and precision of depth information may be also improved.

FIG. 6Ais a schematic diagram showing a structure of an image pickup apparatus600according to another exemplary embodiment,FIG. 6Bis a diagram showing an example of first through ninth image pickup regions611,612,613,614,615,616,617,618, and619of the image pickup apparatus600shown inFIG. 6A, andFIG. 6Cis a diagram showing another example of the first through ninth image pickup regions611,612,613,614,615,616,617,618, and619of the image pickup apparatus600shown inFIG. 6A.

Referring toFIG. 6A, the image pickup apparatus600includes the first lens element601having a first diameter, the second through fifth lens elements602,603,604, and605having a second diameter larger than the first diameter, and the sixth through ninth lens elements606,607,608, and609having a third diameter larger than the second diameter. In other words, the first lens element601has the smallest diameter. Furthermore, the second through fifth lens elements602,603,604, and605have the same diameter that is larger than the diameter of the first lens element601, and the sixth through ninth lens elements606,607,608, and609have the largest diameter. Therefore, the first lens element601has the largest F number, and the sixth through ninth lens elements606,607,608, and609have the smallest F number.

The first through ninth lens elements601,602,603,604,605,606,607,608, and609are 2-dimensionally disposed in a horizontal direction and a vertical direction, when viewed from a rear, front, or surface of the image pickup apparatus600. In this example, the second through fifth lens elements602,603,604, and605are disposed in a horizontal direction and a vertical direction around the first lens element601, and the sixth through ninth lens elements606,607,608, and609are disposed in diagonal directions around the first lens element601. In other words, the sixth through ninth lens elements606,607,608, and609are respectively disposed on four vertices of a quadrangle on the rear, front, or surface of the image pickup apparatus, the second through fifth lens elements602,603,604, and605are respectively disposed at the centers of four sides of the quadrangle, and the first lens element601is disposed in the center of the quadrangle.

Furthermore, referring toFIG. 6B, the first through ninth image pickup regions611,612,613,614,615,616,617,618, and619respectively corresponding to the first through ninth lens elements601,602,603,604,605,606,607,608, and609are disposed. The first through ninth image pickup regions611,612,613,614,615,616,617,618, and619may have different sizes and pixel pitches from one another. In this example, the first through fifth image pickup regions611,612,613,614, and615have the same first size, whereas the sixth through ninth image pickup regions616,617,618, and619have a second size smaller than the first size. Therefore, images obtained via the first through fifth image pickup regions611,612,613,614, and615have the same first angle of view, whereas images obtained via the sixth through ninth image pickup regions616,617,618, and619have a second angle of view narrower than the first angle of view. Although not shown, the first through fifth image pickup regions611,612,613,614, and615may have a first pixel pitch, whereas the sixth through ninth image pickup regions616,617,618, and619may have a second pixel pitch smaller than the first pixel pitch.

FIG. 6Bshows the example in which the first through ninth image pickup regions611,612,613,614,615,616,617,618, and619respectively include separate image sensors. Referring toFIG. 6C, the first through ninth image pickup regions611,612,613,614,615,616,617,618, and619are logically divided regions in a single image sensor610. In this case, the first through fifth image pickup regions611,612,613,614, and615have the same first size, whereas the sixth through ninth image pickup regions616,617,618, and619have the same second size smaller than the first size. Although not shown, the first pickup region611may have a first pixel pitch, second through fifth image pickup regions612,613,614, and615may have the same second pixel pitch smaller than the first pixel pitch, and the sixth through ninth image pickup regions616,617,618, and619may have the same third pixel pitch smaller than the second pixel pitch.

In the above-stated structure, pairs of the second through fifth lens elements602,603,604, and605and pairs of the sixth through ninth lens elements606,607,608, and609have not only horizontal parallaxes, but also vertical parallaxes. Therefore, depth information may be extracted not only in a horizontal direction, but also in a vertical direction. Here, the sixth through ninth lens elements606,607,608, and609are disposed at the outermost locations, such that distances between the sixth through ninth lens elements606,607,608, and609providing a telescopic zoom function are the largest. Furthermore, resolutions of five images having a first angle of view obtained via the first through fifth image pickup regions611,612,613,614, and615may be improved by using the super resolution technique, and resolutions of four images having a second angle of view obtained via the sixth through ninth image pickup regions616,617,618, and619may be improved by using the super resolution technique. Furthermore, by using the super resolution technique, an image may be smoothly processed when a digital zoom function for generating an image having an angle of view between a first angle of view and a second angle of view is performed.

FIG. 7is a schematic diagram showing a structure of an image pickup apparatus700according to another exemplary embodiment. Referring toFIG. 7, the image pickup apparatus700includes first through third lens elements701,702, and703having a first diameter and fourth and fifth lens elements704and705having a second diameter larger than the first diameter. Therefore, the first through third lens elements701,702, and703have the same F number, whereas the fourth and fifth lens elements704and705have the same F number. Furthermore, the F number of the fourth and fifth lens elements704and705is smaller than the F number of the first through third lens elements701,702, and703. Although not shown, same as in the above-stated exemplary embodiment, sizes of image pickup regions respectively corresponding to the first through third lens elements701,702, and703may be larger than sizes of image pickup regions respectively corresponding to the fourth and fifth lens elements704and705.

According to the exemplary embodiment, the first through third lens elements701,702, and703are linearly disposed in a horizontal direction (a first direction), whereas the fourth and fifth lens elements704and705are linearly disposed in a vertical direction (a second direction perpendicular to the first direction), when viewed from a rear, front, or surface of the image pickup apparatus700. In this example, the fourth lens element704is disposed below the first through third lens elements701,702, and703, whereas the fifth lens element705is disposed above the first through third lens elements701,702, and703.

In the above-stated structure, because the first through third lens elements701,702, and703have parallaxes in a horizontal direction, depth information in a horizontal direction may be extracted by using three images obtained via the first through third lens elements701,702, and703. Furthermore, because the fourth and fifth lens elements704and705have a parallax in a vertical direction, depth information in a vertical direction may be extracted by using two images obtained via the fourth and fifth lens elements704and705.

Furthermore, images having a first angle of view may be obtained via the first through third lens elements701,702, and703, whereas image having a second angle of view narrower than the first angle of view may be obtained via the fourth and fifth lens elements704and705. Here, resolutions of the three images having the first angle of view obtained via the first through third lens elements701,702, and703may be improved by using the super resolution technique, and resolutions of the two images having the second angle of view obtained via the fourth and fifth lens elements704and705may be improved by using the super resolution technique. By using the super resolution technique, an image may be smoothly processed when a digital zoom function for generating an image having an angle of view between a first angle of view and a second angle of view is performed.