Abstract:
A combination imaging apparatus using a reflector and method are provided. The present combination imaging apparatus and method comprise a lens assembly for forming an optical image corresponding to a subject, and first and second charge-coupled devices (CCDs) each for converting the optical image into an electrical image signal, The apparatus and method further comprise a reflector for changing an optical path of light incident through the lens assembly and forming an optical image on any of the first and second CCDs, and a circuit part for processing, reproducing, and storing the converted optical image of any of the first and second CCDs. Accordingly, the combination imaging apparatus can capture high-quality moving pictures and still images using a single lens assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit under 35 U.S.C. § 119(a) from Korean Patent Application No. 2004-64266 filed on Aug. 16, 2004 in the Korean Intellectual Property Office, the entire disclosure of which is hereby incorporated by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates generally to a combination imaging apparatus using a reflector and a method thereof. More particularly, the present invention relates to a combination imaging apparatus using a reflector and a method thereof, which are capable of forming optical images on a charge-coupled device (CCD) for moving pictures and/or a CCD for still images by changing an optical path of light incident through a lens assembly.  
         [0004]     2. Description of the Related Art  
         [0005]      FIG. 1  is a view of a lens assembly and a charge-coupled device (CCD) unit of a general imaging apparatus. In  FIG. 1 , the image of a subject  10  is formed on a CCD unit  13  through a lens assembly  11 . A moving-picture imaging apparatus such as a camcorder uses a CCD for movies such as an interface CCD as the CCD unit  13  to enhance the moving-picture quality. A still image-capturing apparatus such as a still camera uses a CCD for still images such as a progressive CCD as CCD unit  13  to enhance the sill image quality. When only the CCD for movies is used to capture moving pictures and still images, the quality of still images deteriorates. When only the CCD for still images is used to capture moving pictures and still images, the quality of moving pictures deteriorates. In order to reduce the deterioration, a combination imaging apparatus, also known as a ‘Duo CAM’ is used having a CCD for both movies and still images.  
         [0006]      FIG. 2  is a block diagram of a conventional combination imaging apparatus. In  FIG. 2 , the conventional combination imaging apparatus has a moving-picture imaging unit  20 , a still image-capturing unit  30 , a signal selection unit  40 , an operation unit  50 , a storage unit  60 , an output unit  70 , and a main control unit  80 .  
         [0007]     The moving-picture imaging unit  20  includes a dynamic image (DI) lens assembly  21 , a DI lens driver  22 , a DI imaging unit  23 , a DI imaging unit driver  24 , a DI Correlated Double Sampling (CDS)/Auto Gain Control (AGC)/Analog-to-Digital converter (ADC)  25 , a DI pre-processing unit  26 , a DI signal processor  27 , and a DI pulse generator  28 .  
         [0008]     The DI lens assembly  21  receives light reflected from a subject to be taken and forms on the DI imaging unit  23  an optical image corresponding to the subject. The DI lens driver  22  drives each part of the DI lens assembly  21 , and focuses light to form an image on the DI imaging unit  23 .  
         [0009]     The DI imaging unit  23  converts an optical image formed through the DI lens assembly  21  into an electric image signal field by field. The DI imaging unit driver  24  receives Timing and Sync signals supplied from the DI pulse generator  28 , converts the Timing and Sync signals into a voltage level suitable to read data, and drives the DI imaging unit  23 .  
         [0010]     The DI CDS/AGC/ADC  25  removes noise from the image signal output from the DI imaging unit  23  by using the Correlated Double Sampling, amplifies a level of the image signal by using the auto gain control, and converts the image signal into a digital image signal by using the analog-to-digital converter.  
         [0011]     The DI pre-processing unit  26  receives the digital image signal from the DI CDS/AGC/ADC  25 , and splits the digital image signal into a luminance signal and a color signal. The DI pre-processing unit  26  calculates color distribution, charge saturation amount, auto focus (AF), and so on, from the digital image signal, and uses the calculations to drive the DI lens assembly  21 .  
         [0012]     The DI signal processor  27  displays on a screen such as a liquid crystal display (LCD) or processes the image signals split into the luminance signal and the color signal to be output to an external device such as a monitor, TV, or the like. The DI pulse generator  28  supplies pulses necessary to operate the DI lens driver  22 , the DI imaging unit  23 , the DI CDS/AGC/ADC  25 , the DI pre-processing unit  26 , and the DI signal processor  27 .  
         [0013]     The still image-capturing unit  30  includes a still image (SI) lens assembly  31 , a SI lens driver  32 , a SI imaging unit  33 , a SI imaging unit driver  34 , a SI CDS/AGC/ADC  35 , a SI pre-processing unit  36 , a SI signal processor  37 , and a SI pulse generator  38 .  
         [0014]     The SI lens assembly  31  receives light reflected from a subject to be taken and forms on the SI imaging unit  33  an optical image corresponding to the subject. The SI lens driver  32  drives each part of the SI lens assembly  31 , and focuses light to form an image on the SI imaging unit  33 .  
         [0015]     The SI imaging unit  33  converts an optical image formed through the SI lens assembly  31  into an electrical image signal frame by frame. The SI imaging unit driver  34  receives Timing and Sync signals supplied from the SI pulse generator  38 , converts the Timing and Sync signals into a voltage level suitable to read data, and drives the SI imaging unit  33 .  
         [0016]     The SI CDS/AGC/ADC  35  removes noise from the image signal output from the SI imaging unit  33  by using the Correlated Double Sampling, amplifies a level of the image signal by using the auto gain control, and converts the image signal into a digital image signal by using the analog-to-digital converter.  
         [0017]     The SI pre-processing unit  36  receives the digital image signal from the SI CDS/AGC/ADC  35 , and splits the digital image signal into a luminance signal and a color signal. The SI pre-processing unit  36  calculates color distribution, charge saturation amount, auto focus (AF), and so on, from the digital image signal, and uses the calculations to drive the SI lens assembly  31 .  
         [0018]     The SI signal processor  37  displays on a screen such as a LCD or processes the image signals split into the luminance signal and the color signal to be output to an external device such as a monitor, TV, or the like. The SI pulse generator  38  supplies pulses necessary to operate the SI lens driver  32 , the SI imaging unit  33 , the SI CDS/AGC/ADC  35 , the SI pre-processing unit  36 , and the SI signal processor  37 .  
         [0019]     The signal selection unit  40  selects one of the moving-picture signal and the still-image signal under the control of the main controller  80 . The operation unit  50  is a user interface for receiving operation commands by a user that are related to the function selections and operation controls of the combination imaging apparatus. The storage unit  60  has a memory driver (not shown) and a memory unit (not shown) such as a memory card, a memory stick, and a hard disc drive (HDD) for storing moving pictures and still images. The output unit  70  displays an image signal being captured, or displays an image signal stored in the storage unit  60 .  
         [0020]     The main controller  80  receives an operation command from a user through the operation unit  50 , and controls the overall operations of the combination imaging apparatus to capture moving pictures and still images. That is, the main controller  80  controls the moving-picture imaging unit  20  and the still image-capturing unit  30  based on the user&#39;s command, and controls the signal selection unit  40  to select one of the moving-picture signal and the still-image signal.  
         [0021]     The conventional combination imaging apparatus needs two lens assemblies and imaging units, so two lens drivers and imaging unit drivers are needed to drive the lens assemblies and the imaging units as well. Furthermore, the circuits for lens driving and image processing become complicated. Therefore, since there is a drawback to miniaturizing the combination imaging apparatus and user manipulations become complicated, operation of the apparatus becomes inconvenient.  
         [0022]     Accordingly, there is a need for a miniaturized combination imaging apparatus having a simplified construction.  
       SUMMARY OF THE INVENTION  
       [0023]     The present invention has been developed in order to solve at least the above described drawbacks and other problems associated with the conventional arrangement and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a combination imaging apparatus and method capable of capturing moving pictures and still images by using a reflector for changing an optical path of light incident through one lens assembly and by forming an optical image on a charge-coupled device (CCD) for movies and a CCD for still images.  
         [0024]     The foregoing and other aspects and advantages are substantially realized by providing a combination imaging apparatus, comprising a lens assembly for forming an optical image corresponding to a subject; first and second charge-coupled devices (CCDs) each for converting the optical image into an electrical image signal; a reflector for changing an optical path of light incident through the lens assembly and forming an optical image on any of the first and second CCDs; and a circuit part for processing, reproducing, and storing the converted optical image of any of the first and second CCDs.  
         [0025]     The reflector changes a tilt of an axis of the light incident through the lens assembly to change an optical path of the light.  
         [0026]     The combination imaging apparatus further comprises a focusing lens for forming the optical image on any of the first and second CCDs by preventing the changed light from being scattered.  
         [0027]     If the optical image is left-right-reversed by the reflector, formed on the first and second CCDs, and converted into the electrical image signal, the circuit part converts the electrical image signal into an electrical image signal corresponding to a normal image.  
         [0028]     One of the first and second CCDs is a CCD for movies, and the other is a CCD for still images.  
         [0029]     Another aspect of the present invention is to provide an image-capturing method for a combination imaging apparatus having a first CCD, a second CCD, and a lens assembly, comprising steps of (a) positioning a reflector for changing an optical path of light incident through a lens assembly; (b) changing by the reflector the optical path of the light to form an optical image of a subject on any of the first and second CCDs; (c) converting the optical image into an electrical image signal; and (d) processing, reproducing, and storing the converted electric image signal.  
         [0030]     In the step (b), the reflector tilts an axis of the light incident through the lens assembly to change the optical path of the light, and the reflector prevents from being scattered the light traveling along the changed optical path to form the optical image on any of the first and second CCDs.  
         [0031]     If the optical image is left-right-reversed by the reflector, formed on any of the first and second CCDs, and converted into the electrical image signal, the step of processing the electrical image signal converts the electrical image signal into an electrical image signal corresponding to the normal image.  
         [0032]     One of the first and second CCDs is a CCD for movies and the other is a CCD for still images. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0033]     The above aspects and features of the present invention will be more apparent by describing certain embodiments of the present invention with reference to the accompanying drawings, in which:  
         [0034]      FIG. 1  illustrates a structure of a conventional lens assembly and an imaging unit of a general imaging apparatus;  
         [0035]      FIG. 2  is a block diagram of a conventional combination imaging apparatus;  
         [0036]      FIG. 3  is a block diagram of a combination imaging apparatus according to an embodiment of the present invention;  
         [0037]      FIG. 4A  illustrates an optical image formation on a first CCD of the combination imaging apparatus of  FIG. 3 ;  
         [0038]      FIG. 4B  illustrates an optical image formation on a second CCD of the combination imaging apparatus of  FIG. 3 ;  
         [0039]      FIG. 5  illustrates operations of an imaging unit of the combination imaging apparatus of  FIG. 3 ;  
         [0040]      FIG. 6A  illustrates an optical image formed on the first CCD of the combination imaging apparatus of  FIG. 3 ; and  
         [0041]      FIG. 6B  illustrates an optical image formed on the second CCD of the combination imaging apparatus of  FIG. 3 .  
     
    
       [0042]     Throughout the drawings, like reference numbers will be understood to refer to like elements, features and structures.  
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0043]     Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.  
         [0044]      FIG. 3  is a block diagram of a combination imaging apparatus according to an embodiment of the present invention. In  FIG. 3 , the combination imaging apparatus includes a lens assembly  100 , an imaging unit  200 , and a circuit  400 . The lens assembly  100  receives light reflected from a subject to be picture-taken. The light incident through the lens assembly  100  forms an optical image on the imaging unit  200 . The imaging unit  200  includes a first charge-couple device (CCD)  230  and a second CCD  250 . The first and second CCDs  230  and  250  form optical images thereon, and convert the optical image into an electrical image signal.  
         [0045]     The circuit  400  includes a lens driver  410 , an imaging unit driver  420 , a pulse generator  425 , a first Correlated Double Sampling (CDS)/Auto Gain Control (AGC)/Analog to Digital Converter (ADC)  430 , a second CDS/AGC/ADC  435 , a first pre-processing unit  440 , a second pre-processing unit  445 , a signal selection unit  450 , a output signal processing unit  455 , an output unit  460 , a storage unit  470 , an operation unit  480 , and a control unit  490 .  
         [0046]     The lens driver  410  drives each part of the lens assembly  100  under the control of the control unit  490  which will be described below. The imaging unit driver  420  receives Timing and Sync signals from the pulse generator  425 , drives the imaging unit  200  by converting the signals into a suitable voltage level for reading data from the imaging unit  200 . The reflector  210  is driven according to user&#39;s manipulations when a user wants to electrically drive the reflector  210  which will be described below in detail in  FIG. 5 .  
         [0047]     The first and second CDS/AGC/ADC  430  and  435  remove noise from the image signal output from the imaging unit  200  by using the Correlated Double Sampling (CDS), amplifies a level of the image signal by using the auto gain control (AGC), and converts the image signal into a digital image signal by using the analog-to-digital converter (ADC).  
         [0048]     The first and second pre-processing units  440  and  445  receive a digital image signal from the first and second CDS/AGC/ADC  430  and  435 , and split the digital image signal into a luminance signal and a color signal. The first and second pre-processing units  440  and  445  calculate and use color distribution, charge saturation amount, auto focus (AF), and so on, to drive each part of the lens assembly  100 .  
         [0049]     The pulse generator  425  generates and supplies Time and Sync signals necessary for parts of the combination imaging apparatus such as the lens driver  410 , the imaging unit driver  420 , the first CDS/AGC/ADC  430 , the second CDS/AGC/ADC  435 , the first pre-processing unit  440 , and the second pre-processing unit  445 .  
         [0050]     The signal selection unit  450  selects one of a moving-picture signal and a still image signal under the control of the control unit  490 . The storage unit  470  has a memory unit (not shown) such as a memory card, a memory stick, a hard disc drive, and so on, and a memory unit driver (not shown) having moving pictures and still images stored into the memory unit. The operation unit  480  is a user interface unit for receiving user&#39;s operation commands relating to function selections and operation controls of the combination imaging apparatus.  
         [0051]     The output signal processing unit  455  processes an image signal split into a luminance signal and a color signal to display the image signal on a screen such as a LCD, or to output the image signal to an external device such as a monitor, TV, and the like. The output unit  460  displays captured images, or displays or outputs an image signal stored in the storage unit  470  according to user&#39;s manipulations.  
         [0052]     The control unit  490  receives a user operation commands through the operation unit  480 , and controls the overall operations of the combination image apparatus to capture moving pictures and still images. That is, the control unit  490  controls the signal selection unit  450  to select one of the moving-picture signals and the still-image signal according to a user&#39;s operation command. The control unit  490  controls the lens driver  410  to drive the lens assembly  100  based on the color distribution, charge saturation amount, auto focus (AF), and so on, that are calculated from the first and second pre-processing units  440  and  445 . The calculated color distribution is used to adjust white balance based on red, blue, and green, and the charge saturation amount is used to adjust brightness and depth of field. The auto focus (AF) is used to automatically focus on a subject.  
         [0053]      FIG. 4A  is a view of an optical image formation on a first CCD of the combination imaging apparatus of  FIG. 3 . In  FIG. 4A , the lens assembly  100  of the combination imaging apparatus includes fixed lenses  110  and  170 , a zoom lens  130 , an iris  150 , and a focus lens  190 .  
         [0054]     If light reflected from the subject  300  is incident through the fixed lens  110 , the zoom lens  130  adjusts the optical image formed on the imaging unit  200  to an image size that can be photographed. That is, the zoom lens  130  can be adjusted to control the telescopic sight and wide angle features of the apparatus without changing positions of the subject  300 .  
         [0055]     The iris  150  adjusts an amount of light incident through the fixed lens  110  and the zoom lens  130  to control the brightness, the depth of field, and so on. If the iris  150  is adjusted to be wider to allow more light, the brighter optical image is obtained and the depth of field of sharpening the area around the focus point becomes shallow. To the contrary, if the iris  150  is adjusted to opened narrowed to reduce the amount of light, the optical image becomes less bright and the depth of field becomes deeper.  
         [0056]     The focus lens  190  focuses on the subject  300  located nearby or far away. That is, the focus lens  190  adjusts its optical focus point to form a clear optical image on the imaging unit  200  after the light reflected from the subject  300  is incident through the lens assembly  100 .  
         [0057]     The imaging unit  200  of the combination imaging apparatus has the reflector  210 , the first CCD  230 , and the second CCD  250 . The reflector  210  changes an optical path of the light incident through the lens assembly  100  in order for the light to converge in the direction of a CCD on which the image is to be formed. The first and second CCD  230  and  250  convert an optical image incident and formed through the lens assembly  100  into an electrical image signal.  FIG. 4A  shows the conversion of an optical image formed on the first CCD  230  into an electrical image signal.  
         [0058]      FIG. 4B  is a view of the formation of an optical image on the second CCD  250  of the combination imaging apparatus of  FIG. 3 . In  FIG. 4B , an optical image of the subject  300  incident through the lens assembly  100  is reflected by the reflector  210 , formed on the second CCD  250 , and converted into an electrical image signal.  
         [0059]     In  FIG. 4A  and  FIG. 4B , a CCD for movies can be used as the first CCD  230 , and the CCD for still images can be used as the second CCD  250 . Otherwise, the CCD for still images can be used as the first CCD  230 , and the CCD for movies can be used as the second CCD  250 . The CCD for still images is suitable for capturing still images, generates an image signal frame by frame according to a progressive scan fashion, and the CCD for movies being suitable for capturing moving pictures, generates an image signal field by field according to an interlace scan fashion.  
         [0060]      FIG. 5  is a view of operations of an imaging unit of the combination imaging apparatus of  FIG. 3 . In  FIG. 5 , the imaging unit  200  has a reflector  210 , a first CCD  230 , a first optical low pass filter (LPF)  235 , a second CCD  250 , a second optical LPF  255 , and a focusing lens  270 .  
         [0061]     The reflector  210  changes an optical path of light to form an optical image on the first CCD  230  or the second CCD  250  according to the selection of a user. The reflector  210  can be changed manually by a user from a position A to a position B, or automatically by electronic means such as a motor and the like. The reflector  210  is operated by the imaging unit driver  420  according to electrical operations. The imaging unit driver  420  is controlled by the control unit  490  receiving user manipulation through the operation unit  480 . The reflector  210  moves from the position A to the position B, and tilted about  45  degrees.  
         [0062]     The first and second optical LPFs  235  and  255  pass light incident from the lens assembly  100  and having frequencies lower than a predetermined frequency, and cut off light having frequencies higher than the predetermined frequency. That is, the first and second optical LPFs  235  and  255  pass only the visible light, and cut off the infrared light to form optical images on the first and second CCDs  230  and  250 , respectively.  
         [0063]     The light passing through the first and second optical LPFs  235  and  255  is turned into optical images on the first and second CCDs corresponding to a subject, and the optical images are converted into electrical image signals by the first and second CCDs  230  and  250 . The focusing lens  290  prevents the light reflected by the reflector  210  from being scattered so as to form an optical image on the second CCD  250 . When the focusing lens  290  is used, high-quality images can be output through the second CCD  250 .  
         [0064]     If the reflector  210  is located at the position A, the light focused through the lens assembly  100  passes through the first optical LPF  235 , forms an optical image on the first CCD  230 , and converts the optical image into an electrical image signal. If the reflector  210  is located on the position B, the light focused through the lens assembly  100  changes its traveling direction due to the reflector  210 . The light in the changed direction is focused through the focusing lens  270 , passes through the second optical LPF  255 , forms an optical image on the second CCD  250 , and converts the optical image into an electrical image signal.  
         [0065]      FIG. 6A  is a view of the formation of an image on the first CCD of the combination imaging apparatus of  FIG. 3 . In  FIG. 6A , light reflected from the subject  300  focuses on the first CCD  230  to form an optical image that is upside down while passing through the lens assembly  100 . The upside-down optical image  310  is converted by the first CCD  230  into an electrical image signal corresponding to the normal optical image  330 . The photoelectric conversion is carried out from a start point S to an end point E in order with respect to data corresponding to the optical image  310  formed on the first CCD  230  in the same manner as conventional methods, and generates an electrical image signal corresponding to the normal optical image  330 .  
         [0066]      FIG. 6B  is a view of the formation of an optical image on the second CCD of the combination imaging apparatus of  FIG. 3 . In  FIG. 6B , an optical image of the subject  300  is turned upside down while the light from the subject  300  passes through the lens assembly  100 , and the upside-down optical image is reversed left and right by the reflector  210  again, and the left-right-reversed optical image is formed on the second CCD  250 . The upside-down and left-right-reversed optical image  350  is converted by the second CCD  250  into an electrical image signal corresponding to the left-right-reversed optical image  370 . That is, the photoelectric conversion is carried out from a start point S to an end point E in order with respect to data corresponding to the optical image  350  formed on the second CCD  250 , and generates an electrical image signal corresponding to the left-right-reversed optical image  370 . A portion of the apparatus for processing an image signal at the rear stage of the second CCD  250  reverses the left and right of the left-right-reversed optical image  370 , and generates an image signal corresponding to the normal optical image  390 . Such an image signal processing can be carried out at the second CDS/AGC/ADC  435 , the second pre-processing unit  445 , or the output signal processing unit  455 .  
         [0067]     As aforementioned, the embodiments of the present invention can miniaturize the combination imaging apparatus and simplify the construction of its entire system circuitry by using the reflector capable of changing a path of the light for an optical image that is incident through one lens assembly to form the optical image on the CCD for movies and the CCD for still images and by capturing high-quality moving pictures and still images through one combination image apparatus.  
         [0068]     The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. Also, the description of the embodiments of the present invention is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.