Abstract:
The present disclosure relates to an endoscopy system. The endoscope system includes: a first light source unit which is installed on a substrate; a second light source unit which is installed on the substrate and which emits light when the first light source unit does not emit light; an optical unit through which the light of the first light source unit or the second light source unit passes; a light guide unit which induces the light which passed through the optical unit to the inside of a target object; an image sensing unit which senses the light reflected and reached from the target object and which converts the sensed light into an image signal; and an image signal processing unit which processes the image signal to display on a display unit.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119 from Korean Application No. 10-2016-0040028 filed on Apr. 1, 2016 and Korean Application No. 10-2016-0079112 filed on Jun. 24, 2016, the subject matter of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0002]    The present disclosure relates to an endoscopy system. 
       Description of the Related Art 
       [0003]    An endoscope system requires a high degree of stability as it is used for medical internal check. The endoscopic system emits a light to the inside of a target object and senses a reflected light to generate a corresponding image of the inside of the target object. 
         [0004]    At this time, when a light source is unable to emit light as it does not work reliably, it is not possible to achieve an image generation, such that a user who uses the endoscope system may not accomplish a medical care or a medical checkup smoothly. 
         [0005]    Accordingly, a research on an endoscopy system is progressed to perform a stable operation even if the light source does not operate normally. 
       SUMMARY OF THE INVENTION 
       [0006]    The present disclosure has been made in view of the above problems, and provides an endoscopic system to generate an image stably even if a light source does not operate normally. 
         [0007]    In accordance with an aspect of the present disclosure, an endoscope system includes: a first light source unit which is installed on a substrate; a second light source unit which is installed on the substrate and which emits light when the first light source unit does not emit light; an optical unit through which the light of the first light source unit or the second light source unit passes; a light guide unit which induces the light which passed through the optical unit to the inside of a target object; senses the light reflected and reached from the target object and which converts the sensed light into an image signal; and an image signal processing unit which processes the image signal to display on a display unit. The light of the second light source unit passes through the optical unit when the light of the first light source unit does not emit light. The first light source unit is arranged along a central axis of the optical unit, and the second light source unit is arranged to deviate the central axis. The endoscope system further includes a controller which senses whether power is supplied to the first light source unit, and the controller turns a switching unit on by sensing a stop of the supply of the power to supply the power to the second light source unit, when the power is not supplied to the first light source unit. The first light source unit that is supplied with power to emit light is connected to a first resistor and the second light source unit is connected to a second resistor, the first resistor has a small resistance value in comparison with the second resistor, and the power is supplied to the second light source unit through the second resistor when the first light source unit does not emit light. 
         [0008]    In accordance with another aspect of the present disclosure, an endoscope system includes: a first light source unit and a second light source unit which are installed on a substrate; an optical unit through which a light of the first light source unit passes; a driver which moves the substrate so that a light of the second light source unit passes through the optical unit when the first light source unit does not emit light; a light guide unit which induces the light of the first light source unit and the second light source unit which passed through the optical unit to the inside of a target object; an image sensing unit which senses the light reflected and reached from the target object and which converts the sensed light into an image signal; and an image signal processing unit which processes the image signal to display on a display unit. The first light source unit is arranged along the optical unit and a central axis when the first light source unit emits light, and the driver rotates the substrate so that the second light source unit is arranged along the optical unit and the central axis when the first light source unit does not emit light. The endoscope system further includes an additional substrate, and a third light source unit and a fourth light source unit installed on the additional substrate, and the driver moves the additional substrate so that a light of the fourth light source unit passes through the optical unit when the third light source unit does not emit light. The light of the third light source unit and the fourth light source unit passes through the optical unit through a groove or a hole formed in the substrate. The first light source unit and the third light source unit that emit light are located closer to the central axis of the optical unit in comparison with the second light source unit and the fourth light source unit respectively, and the driver rotates the substrate when the first light source unit does not emit light so that the second light source unit is positioned to be close to the central axis in comparison with the first light source unit, and rotates the substrate when the third light source unit does not emit light so that the fourth light source unit is positioned to be close to the central axis in comparison with the third light source unit. The first light source unit and the third light source unit emit a light of a different wavelength simultaneously, and, when the first light source unit and the third light source unit does not emit light, the second light source unit and the fourth light source unit emit a light of a different wavelength simultaneously. The first light source unit is arranged along the optical unit and the central axis when the first light source unit emits light, and the driver moves the substrate linearly so that the second light source unit is arranged along the optical unit and the central axis when the first light source unit does not emit light. The endoscope system further includes a controller which senses a stop of a supply of a power to at least one of the first light source unit and the third light source unit, and the controller controls a switching unit to supply power to the second light source unit when a supply of a power to the first light source unit is stopped, and to supply power to the fourth light source unit when a supply of a power to the third light source unit is stopped. The first light source unit and the third light source unit are connected to a first resistor and the second light source unit and the fourth light source unit are connected to a second resistor, the first resistor has a small resistance value in comparison with the second resistor, and a power is supplied to the second light source unit and the fourth light source unit through the second resistor when the first light source unit and the third light source unit are unable to emit light. 
         [0009]    In accordance with another aspect of the present disclosure, an endoscope system includes: a first light source unit which is installed on a substrate, and which is provided with a first terminal; a second light source unit which is installed on the substrate and which is provided with a second terminal in a non-boundary area which is not a boundary area with the first light source unit to emit light when the first light source unit does not emit light; an optical unit through which the light of the first light source unit or the second light source unit passes; a light guide unit which induces the light which passed through the optical unit to the inside of a target object; an image sensing unit which senses the light reflected and reached from the target object and which converts the sensed light into an image signal; and an image signal processing unit which processes the image signal to display on a display unit. The first light source unit and the second light source unit include total n partial light sources, and, when the first light source unit includes m (m&lt;n, m and n is a natural number) partial light sources, the second light source unit includes partial light source which is equal to or greater than one and equal to or less than n-m. The first light source unit is arranged along a central axis of the optical unit, and the second light source unit is arranged to deviate the central axis. The first light source unit and the second light source unit further include an additional optical unit covering a light source mounted on the substrate, and a cross-sectional shape of the additional optical unit is curved or flat with respect to a direction of a light. The first light source unit and the second light source unit further include an additional optical unit covering a light source mounted on the substrate, and the additional optical unit performs a function of a Fresnel lens. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The objects, features and advantages of the present disclosure will be more apparent from the following detailed description in conjunction with the accompanying drawings, in which: 
           [0011]      FIG. 1  illustrates an implementation of an endoscope system according to an embodiment of the present disclosure; 
           [0012]      FIG. 2  and  FIG. 3  illustrate an endoscope system according to a first embodiment of the present disclosure; 
           [0013]      FIG. 4  and  FIG. 7  illustrate an endoscope system according to a second embodiment of the present disclosure; 
           [0014]      FIG. 5  and  FIG. 6  illustrate a modification of the endoscope system according to the second embodiment of the present disclosure; 
           [0015]      FIG. 8  and  FIG. 9  illustrate an operation of a controller of the endoscope system according to the first embodiment of the present disclosure; 
           [0016]      FIG. 10  to  FIG. 12  illustrate an operation of a controller of the endoscope system according to the second embodiment of the present disclosure; 
           [0017]      FIG. 13  illustrates a cross-sectional shape of a substrate; 
           [0018]      FIG. 14  to  FIG. 16  illustrate a first light source unit and a second light source unit of an endoscope system according to a third embodiment of the present disclosure; 
           [0019]      FIG. 17  illustrates a comparative example of the endoscope system according to the third embodiment of the present disclosure; 
           [0020]      FIG. 18  illustrates a cross-section of the first light source unit and the second light source unit; 
           [0021]      FIG. 19  illustrates an additional optical unit; and 
           [0022]      FIG. 20  is a block diagram illustrating an endoscope system according to embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0023]    Exemplary embodiments of the present disclosure are described with reference to the accompanying drawings in detail. The same reference numbers are used throughout the drawings to refer to the same or like parts. Detailed descriptions of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of the present disclosure. 
         [0024]    The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. 
         [0025]    In the present disclosure, the terms such as “include” and/or “have” may be construed to denote a certain characteristic, number, step, operation, constituent element, component or a combination thereof, but may not be construed to exclude the existence of or a possibility of addition of one or more other characteristics, numbers, steps, operations, constituent elements, components or combinations thereof. 
         [0026]      FIG. 1  illustrates an implementation of an endoscope system according to an embodiment of the present disclosure. 
         [0027]    Referring to  FIG. 1 , the endoscope system according to an embodiment of the present disclosure may include a light emitting unit  10 , a light guide unit  20 , an image sensing unit  30 , and an image signal processing unit  40 . 
         [0028]    The light emitting unit  10  may emit light of various wavelengths such as visible light, ultraviolet rays, and infrared rays. 
         [0029]    The configuration of the light emitting unit  10  is described in more detail later. 
         [0030]    The light guide unit  20  may derive the light generated by the light emitting unit  10  to the inside of a target object. The target object may be a person, an animal, a product, or the like, but it is not limited thereto. 
         [0031]    The image sensing unit  30  may sense the light which is reflected from the target object and convert the sensed light into an image signal. To this end, the image sensing unit  30  may include a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS), but it is not limited thereto. 
         [0032]    The image signal processing unit  40  may process the image signal to display on a display unit (not shown) such as a monitor or TV. 
         [0033]    Next, the endoscope system according to an embodiment of the present disclosure is described with reference to the drawings. In the following drawings, the light emitting unit  10  is mainly shown for the convenience of explanation. The light emitting unit  10  may include a first light source unit  100  and a second light source unit  200 , and may further include a third light source unit  700  and a fourth light source unit  800 . 
         [0034]    As shown in  FIG. 2 , the endoscope system according to a first embodiment of the present disclosure may include the first light source unit  100 , the second light source unit  200 , an optical unit  300 , and the light guide unit  20 . 
         [0035]    The first light source unit  100  may be installed on a substrate  400 . 
         [0036]    The second light source unit  200  may be installed on the substrate  400  and emit light when the first light source unit  100  does not emit light. At this time, the second light source unit  200  may be installed close to the first light source unit  100 , but it is not limited thereto. In  FIG. 2 , the number of the second light source unit  200  is four, but it is not limited thereto and may be equal to or greater than one. 
         [0037]    The first light source unit  100  and the second light source unit  200  may include an LED, but it is not limited thereto. In  FIG. 2 , it is illustrated that the first light source unit  100  and the second light source unit  200  include a single LED but may include a plurality of LEDs. In addition, in the following drawings, it is illustrated that the first light source unit  100  and the second light source unit  200  include a single LED but may include a plurality of LEDs. 
         [0038]    The first light source unit  100  and the second light source unit  200  may, as if a white light, emit light of various wavelengths such as visible light, ultraviolet rays, and infrared rays. 
         [0039]    The light of the first light source unit  100  or the second light source unit  200  may pass through the optical unit  300 . At this time, a central axis may be a central axis  300  of the optical unit  300 . 
         [0040]    At this time, the optical unit  300  may include a collimator, but it is not limited thereto, and may include various lenses according to the needs of design. 
         [0041]    The installation location of the optical unit  300  may be installed in an area where the light emitting unit  10  and an optical fiber  15  are connected, but it is not limited thereto. The optical fiber  15  may provide a path where a light passed through the optical unit  300  progresses to the light guide unit  20 . 
         [0042]    To this end, the optical fiber  15  may be connected to a handle  25 , and the handle  25  may be connected to the light guide unit  20 , but it is not limited to this structure. A doctor or an operator may operate the endoscope system according to an embodiment of the present disclosure through the handle  25 . 
         [0043]    The light guide unit  20  may guide a light passed through the optical unit  300  into the inside of the target object. 
         [0044]    As this time, as shown in  FIG. 2 , when the light of the first light source unit  100  is not emitted, the light of the second light source unit  200  may pass through the optical unit  300  in the state in which the substrate  400  does not move at all. 
         [0045]    Thus, the second light source unit  200  may emit light when the first light source unit  100  does not emit light due to failure after emitting light, such that it is possible to accomplish a stable operation of the endoscope system. 
         [0046]    For example, when a doctor performs a treatment or a surgery through a general endoscope system, if a light is not emitted from the endoscope system, the treatment or the surgery may not be performed smoothly. 
         [0047]    On the other hand, even if the first light source unit  100  does not emit light due to a failure or the like, the endoscope system according to an embodiment of the present disclosure may emit light through the second light source unit  200 , such that doctor may perform the treatment or the surgery more stably. 
         [0048]    In addition, since there is no movement of the substrate  400 , a drive system for moving the substrate  400  is not necessary, so that the endoscope system may be simply configured. On the other hand, as shown in  FIG. 2 , the first light source unit  100  may be arranged based on a central axis of the optical unit  300 , and the second light source unit  200  may be placed to get out of the central axis. 
         [0049]    The first light source unit  100  may be arranged based on the central axis of the optical unit  300  so as to supply a sufficient amount of light to the light guide unit  20  while the endoscope system of the present disclosure is operating normally. 
         [0050]    On the other hand, when an abnormal operation that the first light source unit  100  does not emit light is accomplished, the substrate  400  does not move, such that the second light source unit  200  may provide an amount of light that can respond to the abnormal operation of the endoscope system although it stray out of the central axis. 
         [0051]    As shown in  FIG. 3 , the substrate  400  may include a first substrate  410  and a second substrate  430 . The first light source unit  100  may be installed in the first substrate  410  and the second light source unit  200  may be installed in the second substrate  430 . 
         [0052]    When the first light source unit  100  is not operated normally, the first substrate  410  may be separated from the second substrate  430  to be replaced with a new first substrate  410  in the maintenance/repair procedure of the endoscope system. 
         [0053]    The first substrate  410  may be pressed in the hole of the second substrate  430 , but the combination and the separation of the first substrate  410  and the second substrate  430  may be implemented through various configurations. 
         [0054]    Meanwhile,  FIG. 4  and  FIG. 7  illustrate an endoscope system according to a second embodiment of the present disclosure. As shown in  FIG. 4  and  FIG. 7 , the endoscope system according to a second embodiment of the present disclosure may include the first light source unit  100 , the second light source unit  200 , the optical unit  300 , a driver  500 , and the light guide unit  20 . 
         [0055]    The first light source unit  100  and the second light source unit  200  may be installed on the substrate  400 . The first light source unit  100  and the second light source unit  200  may emit, as if white light, a light of various wavelengths such as visible light, ultraviolet rays, and infrared rays. 
         [0056]    The light of the first light source unit  100  may pass through the optical unit  300 . Since the optical unit  300  is described above in detail, an explanation thereof is omitted. 
         [0057]    The driver  500  may move the substrate  400  so that the light of the second light source unit  200  may pass through the optical unit  300  when the first light source unit  100  does not emit light. 
         [0058]    The driver  500  may be connected with a drive shaft, and the drive shaft may be connected with the substrate  400 . Accordingly, the driver  500  may rotate the substrate  400  through the drive shaft, and, for this purpose, may include a motor. 
         [0059]    The light guide unit  20  may guide the light of the first light source unit  100  or the second light source unit  200  which has passed through the optical unit  300  into the inside of the target object. 
         [0060]    As described above, when the first light source unit  100  is unable to perform a normal operation, the driver  500  may move the substrate  400  such that the light of the second light source unit  200  may pass through the optical unit  300 . Thus, a stable operation of the endoscope system may be achieved. 
         [0061]    The method of moving the substrate  400  may include various schemes such as a rotation scheme and a sliding scheme. The driver  500  of the endoscopic system of  FIG. 4  may operate according to a rotation scheme, and the driver  500  of the endoscopic system of  FIG. 7  may operate according to a sliding scheme. 
         [0062]    The rotation scheme is described first and then the sliding scheme is described. 
         [0063]    As shown in  FIG. 4 , when the first light source unit  100  emit light, the first light source unit  100  may be arranged along the optical unit  300  and a central axis. At this time, the central axis may be a central axis of the optical unit  300 . 
         [0064]    When the first light source unit  100  does not emit light due to failure or the like, the driver  500  may rotate the substrate  400 , so that the second light source unit  200  may be arranged along the optical unit  300  and the central axis. 
         [0065]    In the meantime, as shown in  FIG. 5 , the endoscope system according to a second embodiment of the present disclosure may further include an additional substrate  600 , and a third light source unit  700  and a fourth light source unit  800  which are installed in the additional substrate  600 . 
         [0066]    The third light source unit  700  and the fourth light source unit  800  may emit the light of a different wavelength from the first light source unit  100  and the second light source unit  200 . For example, when the first light source unit  100  and the second light source unit  200  emit a white light, the third light source unit  700  and the fourth light source unit  800  may emit ultraviolet rays or infrared rays. 
         [0067]    When the third light source  700  does not emit light, the driver  500  of  FIG. 5  may move the additional substrate  600  so that the light of the fourth light source unit  800  may pass through the optical unit  300 , and the light of the third light source unit  700  or the fourth light source  800  may pass through the optical unit  300  through a groove ( 400   a ) or a hole ( 400   a ) formed in the substrate  400 . 
         [0068]    At this time, the first light source unit  100  and the third light source unit  700  may emit a light of a different wavelength simultaneously, and, when the first light source unit  100  and the third light source unit  700  do not emit light, the second light source unit  200  and the fourth light source unit  800  may emit a light of a different wavelength simultaneously. 
         [0069]    When the first light source unit  100  and the third light source unit  700  emit a light of different wavelength simultaneously, or when the second light source unit  200  and the fourth light source unit  800  emit a light of different wavelength simultaneously, a composite image which is obtained by synthesizing an image corresponding to each wavelength may be displayed through a display unit. 
         [0070]    In the case of the endoscope system of  FIG. 5 , a single rotation shaft may be connected to the substrate  400  and the additional substrate  600 . On the other hand, a rotation shaft of the substrate  400  and a rotation shaft of additional substrate  600  may be separately provided. 
         [0071]    In the meantime, the endoscope system of  FIG. 6  may also further include the substrate  600 , and the third light source unit  700  and the fourth light source unit  800  which are installed in the additional substrate  600 . 
         [0072]    The first light source unit  100  and the third light source unit  700  that emit light may be located closer to the central axis of the optical unit  300  in comparison with the second light source unit  200  and the fourth light source unit  400  respectively. 
         [0073]    At this time, when the first light source unit  100  does not emit light, the driver  500  may rotate the substrate  400  so that the second light source unit  200  may be located closer to the central axis in comparison with the first light source unit  100 . 
         [0074]    In addition, when the third light source unit  700  does not emit light, the driver  500  may rotate the additional substrate  600  so that the fourth light source unit  800  may be located closer to the central axis in comparison with the third light source unit  700 . 
         [0075]    Accordingly, light may pass through the optical unit  300  as much as possible in the state in which the first light source unit  100  to the fourth light source unit  800  are not arranged in the central axis of the optical unit  300 . 
         [0076]    The wavelength of the light of the first light source unit  100  may be different from the wavelength of the light of the third light source unit  700  and the fourth light source unit  800 , and the wavelength of the light of the second light source unit  200  may also be different from the wavelength of the light of the third light source unit  700  and the fourth light source unit  800 . 
         [0077]    In the endoscope system of  FIG. 6 , the first light source unit  100  and the third light source unit  700  may emit light of a different wavelength simultaneously, and, when the first light source unit  100  and the third light source unit  700  does not emit light, the second light source unit  200  and the fourth light source unit  800  may emit light of a different wavelength simultaneously. 
         [0078]    As shown in  FIG. 5  and  FIG. 6 , the driver  500  may be connected to the rotation axis of the substrate  400  and the additional substrate  600  to rotate the substrate  400  and the additional substrate  600 . 
         [0079]    Next, the sliding scheme which is different from the rotation scheme is described. 
         [0080]    As shown in  FIG. 7 , when the first light source unit  100  emits light, the first light source unit  100  may be arranged along the optical unit  300  and the central axis. When the first light source unit  100  does not emit light, the driver  500  may move the substrate  400  linearly such that the second light source unit  200  may be arranged along the optical unit  300  and the central axis. 
         [0081]    In the case of the rotation scheme, the driver  500  may be connected to the rotation axis of the substrate  400  or the additional substrate  600 . In the case of the sliding scheme, the driver  500  may move the substrate  400  by making a piston to perform a linear motion, but it is not limited thereto, and may apply various structures for the linear motion of the substrate  400 . 
         [0082]    Next, a controller according to the first embodiment and the second embodiment of the present disclosure is described with reference to the drawings. 
         [0083]    As shown in  FIG. 8  and  FIG. 9 , the endoscope system according to the first embodiment of the present disclosure may further include a controller  900 . 
         [0084]    As shown in  FIG. 8 , a power supply (PWR) may supply power to the first light source unit  100  and the second light source unit  200 , and the controller  900  may sense whether power is supplied to the first light source unit  100 . 
         [0085]    For example, when the first light source unit  100  includes an LED, the controller  900  may sense a current supplied to the first light source unit  100 . 
         [0086]    When the first light source unit  100  is unable to emit light due to failure, power may not be supplied to the first light source unit  100 . Accordingly, the controller  900  may turn a switching unit (S) on by sensing the stop of the supply of the power. 
         [0087]    At this time, one end of the switching unit (S) may be connected with the second light source unit  200 , and the other end of the switching unit S may be connected with the power supply (PWR), but the connection relation of the switching unit (S) is not limited thereto and may be changed according to a design. 
         [0088]    Accordingly, the second light source unit  200  may be supplied with power and may emit light. 
         [0089]    Meanwhile, as shown in  FIG. 9 , the first light source unit  100  which is supplied with power to emit light may be connected to a first resistor R 1 , and the second light source unit  200  may be connected to a second resistor R 2  have. At this time, the resistance value of the first resistor R 1  may be smaller in comparison with the second resistor R 2 . 
         [0090]    Since the resistance value of the first resistor R 1  is smaller in comparison with the second resistor R 2 , a current flowing in the first light source unit  100  may be larger than a current flowing in the second light source unit  200 . 
         [0091]    At this time, the ratio of the resistance value of the first resistor R 1  and the second resistor R 2  may be set in such a manner that the first light source unit  100  emits light in a normal operation state, and the second light source unit  200  does not emit light. 
         [0092]    When the first light source unit  100  is unable to emit light due to failure, the resistance of the first light source unit  100  may be largely increased, such that the magnitude of current flowing into the first resistor R 1  may be decreased or the flow of the current may be stopped and the magnitude of the current flowing into the second resistor R 2  may be increased. 
         [0093]    When the first light source unit  100  is unable to emit light, the power of the power supply (PWR) may be supplied to the second light source unit  200  through the second resistor R 2 , and thus the second light source unit  200  may emit light. 
         [0094]    As shown in  FIG. 10  to  FIG. 13 , the endoscope system according to the second embodiment of the present disclosure may further include the controller  900 . 
         [0095]    As shown in  FIG. 10  to  FIG. 13 , when at least one of the first light source unit  100  and the third light source unit  700  is unable to emit light, the power of the power supply (PWR) may not be supplied to at least one of the first light source unit  100  and the third light source unit  700 . 
         [0096]    Accordingly, the controller  900  may sense the stop of the supply of power to the at least one of the first light source unit  100  and the third light source unit  700 , and, by controlling the switching unit (S), may supply the power of the power supply (PWR) to the second light source unit  200  when the supply of power to the first light source unit  100  is stopped, and may supply the power of the power supply (PWR) to the fourth light source unit  800  when the supply of power to the third light source unit  700  is stopped. 
         [0097]    That is, as shown in  FIG. 10  and  FIG. 11 , the power of the power supply (PWR) may be supplied to the first light source unit  100  and the third light source unit  700 , and the controller  900  may check whether the power of the power supply (PWR) is supplied to the first light source unit  100  and the third light source unit  700 . 
         [0098]    In  FIG. 10 , the first light source unit  100  and the third light source unit  700  may receive the power of the power supply (PWR) through a wire, and the first light source unit  100  and the third light source unit  700  of  FIG. 11  may receive the power of the power supply (PWR) through a separate wire. 
         [0099]    For example, when the first light source unit  100  and the third light source unit  700  include a LED, the controller  900  may sense the current supplied to the first light source unit  100  and the third light source unit  700 . 
         [0100]    When the first light source unit  100  is unable to emit light due to failure, the power of the power supply (PWR) may not be supplied to the first light source unit  100  and the third light source unit  700 . Accordingly, the controller  900  may turn the switching unit (S) on by sensing the stop of the supply of the power. 
         [0101]    At this time, as shown in  FIG. 10 , one end of the switching unit (S) may be connected with the second light source unit  200  and the fourth light source unit  800 , and the other end of the switching unit (S) may be connected with the power supply (PWR). 
         [0102]    Accordingly, when the first light source unit  100  and the third light source unit  700  are unable to emit light, the switching unit (S) may be turned on according to the control of the controller  900  such that the second light source unit  200  and the fourth light source unit  800  may be supplied with the power of the power supply (PWR) to emit light. 
         [0103]    At this time, the controller  900  may output a driving control signal for moving the substrate  400  or the additional substrate  600  to the driver  500 . 
         [0104]    Alternatively, as shown in  FIG. 11 , the switching unit (S) may include a first switch (sw 1 ) and a second switch (sw 2 ). One end and the other end of the first switch (sw 1 ) may be connected with the second light source unit  200  and the power supply (PWR) respectively, and one end and the other end of the second switch (sw 2 ) may be connected with the fourth light source unit  800  and the power supply (PWR) respectively. 
         [0105]    The connection relation of the switching unit (S) is not limited thereto and may be changed according to the design. For example, the number of switches included in the switching unit (S) may be changed according to the number of the second light source unit  200  and the fourth light source unit  800 . 
         [0106]    Accordingly, when at least one of the first light source unit  100  and the third light source  700  is unable to emit light, the controller  900  may sense that the power of the power supply (PWR) is not supplied to at least one of the first light source unit  100  and the third light source unit  700 . 
         [0107]    Based on the sensing result, the controller  900  may turn on at least one of the first switch (SW 1 ) and the second switch (SW 2 ) to supply the power of the power supply (PWR) to at least one of the second light source unit  200  and the fourth light source unit  800 . 
         [0108]    At this time, the controller  900  may output a driving control signal for moving the substrate  400  or the additional substrate  600  to the driver  500 . 
         [0109]    Meanwhile, as shown in  FIG. 12 , the first light source unit  100  and the third light source unit  700  may be connected to the first resistor R 1 , and the second light source unit  200  and the fourth light source unit  800  may be connected to the second resistor R 2 . 
         [0110]    At this time, the resistance value of the first resistor R 1  may be smaller than that of the second resistor R 2 . At this time, the first light source unit  100  and the second light source unit  200  may be installed on the substrate  400  one by one, and the third light source unit  700  and the fourth light source unit  800  may be installed on the additional substrate  600  one by one. 
         [0111]    Since the resistance value of the first resistor R 1  is smaller than the second resistor R 2 , the current flowing in the first light source unit  100  or the third light source unit  700  may be greater than the current flowing in the second light source unit  200  or the fourth light source unit  800 . 
         [0112]    At this time, the ratio of the resistance value of the first resistor R 1  and the second resistor R 2  may be set in such a manner that the first light source unit  100  or the third light source unit  700  emits light in a normal operation state, and the second light source unit  200  or the fourth light source unit  800  does not emit light. 
         [0113]    When the first light source unit  100  and the third light source unit  700  are unable to emit light due to failure or damage, the resistance of the first light source unit  100  and the third light source unit  700  may be largely increased, such that the magnitude of the current flowing into the first resistor R 1  may be decreased and the magnitude of the current flowing into the second resistor R 2  may be increased. 
         [0114]    Thus, the second light source unit  200  and the fourth light source unit  800  may emit light. That is, when the first light source unit  100  and the third light source unit  700  are unable to emit light, the power of the power supply (PWR) may be supplied to the second light source unit  200  and the fourth light source unit  800  through the second resistor R 2 . 
         [0115]    The controller  900  may sense the magnitude of the current flowing in the first resistor R 1  and the second resistor R 2  and may output a drive control signal to the driver  500  so that it is possible to move the substrate  400  or the additional substrate  600 . 
         [0116]    Meanwhile, as shown in  FIG. 13 , the cross-sectional shape of the substrate  400  of  FIG. 1  may be recessed with respect to the optical unit  300 . Accordingly, even if the second light source unit  200  is not arranged in the central axis of the second light source unit  200 , light may be inputted to the optical unit  300  as much as possible. 
         [0117]    Next, the endoscope system according to a third embodiment of the present disclosure is described with reference to the drawings. 
         [0118]      FIG. 14  to  FIG. 16  illustrate a first light source unit and a second light source unit of an endoscope system according to a third embodiment of the present disclosure, and omit the optical unit  300  for the convenience of explanation. 
         [0119]    The endoscope system according to the third embodiment of the present disclosure may include the first light source unit  100 , the second light source unit  200 , the optical unit  300 , and the light guide unit  20 . 
         [0120]    The first light source unit  100  may be installed on the substrate  400 , and may be provided with a first terminal  150 . 
         [0121]    The second light source unit  200  may be installed on the substrate  400  and may be provided with a second terminal  250  in a non-boundary area which is not a boundary area with the first light source unit  100  and may emit light when the first light source unit  100  does not emit light. 
         [0122]    At this time, the first terminal  150  and the second terminal  250  may include a positive (+) electrode and a negative (−) electrode. 
         [0123]    Like the comparative example of  FIG. 17  which is different from the third embodiment of the present disclosure, when the first terminal  150  and the second terminal  250  exist in the boundary area of the first light source unit  100  and the second light source unit  200 , it can be seen that a gap (G) between the first light source unit  100  and the second light source unit  200  increases in comparison with the third embodiment of the present disclosure. 
         [0124]    Unlike the above comparative example, the third embodiment of the present disclosure may reduce the gap between the first light source unit  100  and the second light source unit  200  as the first terminal  150  and the second terminal  250  do not exist in the boundary area of the first light source unit  100  and the second light source unit  200 . Thus, the size of the substrate  400  may be reduced, and the light emitting unit  10  may also be reduced. 
         [0125]    The light of the first light source unit  100  and the second light source unit  200  may pass through the optical unit  300 . The light guide unit  20  may guide the light which passed through the optical unit  300  into the inside of a target object. Since the optical unit  300  and the light guide unit  20  are described in detail in the above through the first embodiment and the second embodiment, the description thereof is omitted. 
         [0126]    Meanwhile, the first light source unit  100  and the second light source unit  200  may include total n partial light sources, and, when the first light source unit  100  includes m (m&lt;n, m and n is a natural number) partial light sources, the second light source unit  200  may include partial light source which is equal to or greater than one and equal to or less than n−m. 
         [0127]    The endoscope system of  FIG. 14 ,  FIG. 15 , and  FIG. 16  may have two (=n), three (=n), and four (=n) total partial light sources, respectively. In addition, the first light source unit  100  of  FIG. 15 ,  FIG. 16 , and  FIG. 17  may have one (=m), two (=m), and two (=m) total partial light sources, respectively. 
         [0128]    When n=3 and m=1, the partial light sources of the second light source unit  200  may be one or two. 
         [0129]    In addition, when n=4 and m=1, the partial light source of the second light source unit  200  may be one, two, or three. When m=3, the partial light source of the second light source unit  200  may be one. 
         [0130]    Thus, the number of partial light sources of the first light source unit  100  and the second light source unit  200  may be changed depending on the design. 
         [0131]    Meanwhile, the first light source unit  100  may be arranged along the central axis of the optical unit  300 , and the second light source unit  200  may deviate from the central axis. For example, in the case in which the first light source unit  100  and the second light source unit  200  include a single partial light source respectively, when the partial light source of the first light source unit  100  is arranged on the central axis, the partial light source of the second light source unit  200  may be disposed on the substrate  400  in a different location from the partial light source of the first light source unit  100 , such that it deviates from the central axis. 
         [0132]    Thus, since the second light source unit  200  deviates from the central axis, even if the light amount transmitted to the light guide unit  20  is reduced, a clinician may perform a response in accordance with the abnormal operation of the endoscope system such as the failure of the first light source unit  100 . 
         [0133]    In addition, the number of partial light sources of the second light source unit  200  is set to be greater than the number of partial light sources of the first light source unit  100 , it is possible to compensate the reduced amount of light caused by the disposition deviated from the central axis. 
         [0134]    Meanwhile, as shown in  FIG. 18 , the first light source unit  100  and the second light source unit  200  may further include an additional optical unit  350  covering a light source mounted on the substrate  400 . The light source may be LED, but it is not limited thereto. The additional optical unit  350  may be implemented by a resin, but it is not limited thereto. A radiator (HR) may be arranged between the light source and the substrate  400 . 
         [0135]    When the cross-sectional shape of the additional optical unit  350  may be curved or flat with respect to the direction of light. For example, it may be convex as shown in (a) of  FIG. 19  or, on the contrary, may be concave, and may be flat as shown in (b) of  FIG. 19 . 
         [0136]    In addition, the additional optical unit  350  may perform the function of the Fresnel lens as shown in (c) of  FIG. 19 . 
         [0137]    The progress direction of the light may be controlled according to the design of the endoscope system by variously setting the shape of the additional optical unit  350 .  FIG. 20  is a block diagram illustrating an endoscope system according to embodiments of the present disclosure. As shown in  FIG. 20 , the endoscope system according to an embodiment of the present disclosure may include an endoscope  50  which can observe the light of a specific wavelength, an image signal processing unit  40  for driving the endoscope  50  and performing a signal processing of an image picked up by the endoscope  50 , and a display unit  60  for displaying the pickup image of the target object. 
         [0138]    The endoscope  50  may include a flexible or rigid insertion unit  50   a  which is inserted into the target object where light hardly reaches, a handle  25  provided to the insertion unit  50   a , and a universal cord unit  50   c  extended from the side part of the handle  25 , and may be electrically connected to the image signal processing unit  40  through the universal cord unit  50   c.    
         [0139]    In addition, a main body unit of the endoscope  50  may be mainly configured of the insertion unit  50   a  and the handle  25 , and the pickup image signal and the control signals may be transmitted to the image signal processing unit  40  through a cable  1   a ,  3   a.    
         [0140]    An image sensing unit  30  such as CMOS or CCD, a motion detection sensor  1  such as a gyro sensor or an acceleration sensor, and a forceps hole may be provided to the end of the insertion unit  50   a . Since the forceps hole is well known, a description thereof is omitted. 
         [0141]    The image sensing unit  30  may be connected to an image sensor driver through the cable  3   a  which bundled a plurality of signal wires  3   a , and the motion detection sensor  1  may also be connected through the cable  1   a.    
         [0142]    The light guide  20  may be connected to the image signal processing unit  40  through the universal cord unit  50   c  in the insertion unit  30   a . The light guide  20  may guide the light emitted from the light emitting unit  10  to output to the end of the insertion unit  50   a.    
         [0143]    The image signal processing unit  40  is described only for the components related to the image pickup, and a description of the other common components needed for driving is omitted. 
         [0144]    The image signal processing unit  40  may include, at least, an image sensor driver, a gain amplifier, an analog-to-digital converter unit (ADC), a digital signal processing unit (DSP), a digital-to-analog converter unit (DAC), and a CPU. 
         [0145]    The light emitting unit  10  may be driven by receiving power by the driver, and the driver may be controlled by the CPU. 
         [0146]    The endoscopic system according to an embodiment of the present disclosure may generate a stable image as a second light source unit supplies a light when a first light source unit operates abnormally. 
         [0147]    Hereinabove, although the present disclosure has been described with reference to exemplary embodiments and the accompanying drawings, the present disclosure is not limited thereto, but may be variously modified and altered by those skilled in the art to which the present disclosure pertains without departing from the spirit and scope of the present disclosure claimed in the following claims.