Abstract:
A light source apparatus includes: a first light source unit; a second light source unit; and a light source control section that, divides a plurality of light sources in the first light source unit into a first light source group, light from which enters near an optical axis, and a second light source group surrounding the first light source group, and divides a plurality of light sources in the second light source unit into a third light source group, light from which enters near the optical axis, and a fourth light source group surrounding the third light source group, and performs control to decrease an output of the second light source group to be lower than an output of the first light source group and decrease an output of the fourth light source group to be lower than an output of the third light source group.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation application of PCT/JP2012/051819 filed on Jan. 27, 2012 and claims benefit of Japanese Application No. 2011-018498 filed in Japan on Jan. 31, 2011, the entire contents of which are incorporated herein by this reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a light source apparatus, and specifically relates to a light source apparatus that performs control of a light source based on endoscope information. 
         [0004]    2. Description of the Related Art 
         [0005]    Conventionally, when, e.g., an observation via an endoscope is performed, a light source apparatus that supplies illuminating light for illuminating a site to be examined to, e.g., a light guide provided in the endoscope is used.  FIG. 11A  is a diagram illustrating a configuration of a conventional light source apparatus where a large-diameter light guide is connected thereto, and  FIG. 11B  is a diagram illustrating a configuration of a conventional light source apparatus where a small-diameter light guide is connected thereto. 
         [0006]    As illustrated in  FIG. 11A , a conventional light source apparatus  100  includes a light source  101  such as a xenon lamp, a light source group control section  102  that performs turning-on control of the light source  101 , and an optical system  103  including a plurality of lenses  103   a  and  103   b,  the optical system  103  collecting illuminating light from the light source  101 . Such light source apparatus  100  is attachable/detachable to/from an endoscope, and a different type of endoscope is connected to the light source apparatus  100  depending on, e.g., the procedure, the observed site and/or the state of the patient. 
         [0007]    In the example in  FIG. 11A , an endoscope including a large-diameter light guide  104  is connected to the light source apparatus  100 . The illuminating light from the light source  101 , which has been collected by the optical system  103 , enters an end face on the proximal end side of the large-diameter light guide  104 . 
         [0008]    On the other hand, as illustrated in  FIG. 11B , where an endoscope including a small-diameter light guide  105  is connected to the light source apparatus  100 , the illuminating light from the light source  101 , which has been collected by the optical system  103 , does not entirely enter an end face on the proximal end side of the small-diameter light guide  105 . 
         [0009]    Therefore, light source units for an electronic endoscope that when an electronic endoscope including a memory with information relating to a diameter size of a light guide recorded therein is connected thereto, reads the information relating to the diameter size of the light guide, and adjusts a position of the light source unit including a plurality of LEDs based on the read information have been proposed (see, for example, Japanese Patent Application Laid-Open Publication No. 2002-177218). 
         [0010]    Such proposed light source units for an electronic endoscope each adjust the position of the light source unit relative to an entrance end of the light guide according to the diameter size of the light guide so that illuminating light efficiently enters the light guide. 
       SUMMARY OF THE INVENTION 
       [0011]    A light source apparatus according to an aspect of the present invention provides a light source apparatus connectable to a proximal end-side input end of a light guiding channel in an endoscope, the endoscope including an endoscope information storing section that stores endoscope information, the light guiding channel that guides light from the proximal end side to a distal end side, and image pickup means for picking up an image of an object illuminated by illuminating light guided by the light guiding channel, the light source apparatus including: a first light source unit including a plurality of light sources arranged therein, the plurality of light sources each emitting illuminating light in a first wavelength band; a second light source unit including a plurality of light sources arranged therein, the plurality of light sources each emitting illuminating light in a second wavelength band; an in-light source light guiding channel that guides the light emitted from the first light source unit and the light emitted from the second light source unit to the proximal end-side input end of the light guiding channel in the endoscope; and a light source control section that, based on the endoscope information from the endoscope information storing section, divides the plurality of light sources in the first light source unit into a first light source group, light from which enters a vicinity of an optical axis of the proximal end-side input end of the light guiding channel in the endoscope, and a second light source group in a periphery of the first light source group, and divides the plurality of light sources in the second light source unit into a third light source group, light from which enters the vicinity of the optical axis of the proximal end-side input end of the light guiding channel in the endoscope, and a fourth light source group in a periphery of the third light source group, and performs control to decrease an output of the second light source group to be lower than an output of the first light source group and decrease an output of the fourth light source group to be lower than an output of the third light source group. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a diagram illustrating a configuration of an endoscope system including a light source apparatus according to a first embodiment; 
           [0013]      FIG. 2  is a diagram for describing an example of a detailed configuration of a light source unit; 
           [0014]      FIG. 3A  is a diagram for describing an example of a lighting state of a light source unit where a large-diameter light guide is connected thereto; 
           [0015]      FIG. 3B  is a diagram for describing an example of a lighting state of a light source unit where a small-diameter light guide is connected thereto; 
           [0016]      FIG. 4  is a diagram illustrating a configuration of an endoscope system including a light source apparatus according to a second embodiment; 
           [0017]      FIG. 5  is a diagram for describing an example configuration of a detailed configuration of a light source unit; 
           [0018]      FIG. 6  is a diagram for describing an example of a lighting state of a light source unit; 
           [0019]      FIG. 7  is a diagram for describing an example of light adjustment control by a light source unit; 
           [0020]      FIG. 8A  is a diagram for describing an example of another arrangement of LEDs; 
           [0021]      FIG. 8B  is a diagram for describing an example of another arrangement of LEDs; 
           [0022]      FIG. 8C  is a diagram for describing an example of another arrangement of LEDs; 
           [0023]      FIG. 9  is a diagram for describing an example of a light source unit including three light source groups; 
           [0024]      FIG. 10  is a diagram for describing an example of a light source apparatus including a plurality of light source units; 
           [0025]      FIG. 11A  is a diagram illustrating a configuration of a conventional light source apparatus where a large-diameter light guide is connected thereto; and 
           [0026]      FIG. 11B  is a diagram illustrating a configuration of a conventional light source apparatus where a small-diameter light guide is connected thereto. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    Embodiments of the present invention will be described below with reference to the drawings. 
       First Embodiment 
       [0028]      FIG. 1  is a diagram illustrating a configuration of an endoscope system including a light source apparatus according to a first embodiment. 
         [0029]    As illustrated in  FIG. 1 , an endoscope system  1  includes an endoscope  2  that picks up an image of an object inside a living body, and a light source apparatus  3  that supplies illuminating light for illuminating the object to the endoscope  2 . 
         [0030]    The endoscope  2  can be attached/detached to/from the light source apparatus  3  via, e.g., a non-illustrated connector. The endoscope  2  includes, in its inside, a light guide  4  inserted from the proximal end side to the distal end side, the light guide  4  guiding illuminating light from the light source apparatus  3 , and an endoscope information storing section  5  with diameter information relating to a diameter size of the light guide  4  (hereinafter also referred to as “endoscope information”) stored therein. 
         [0031]    An end face on the light entrance side (hereinafter also referred to as “proximal end-side input end”) of the light guide  4  is arranged on the proximal end side of the endoscope  2 , and an end face on the light exit side (hereinafter also referred to as “distal end-side output end”) of the light guide  4  is arranged on the distal end side of the endoscope  2 . Where the endoscope  2  is connected to the light source apparatus  3 , the proximal end-side input end of the light guide  4  is connected to the light source apparatus  3 . The light guide  4 , which serves as a light guiding channel, guides illuminating light inputted to the proximal end-side input end to the distal end-side output end. With such configuration as described above, illuminating light emitted from the light source apparatus  3  enters the proximal end-side input end and then exits from the distal end-side output end of the light guide  4 , and illuminates an object inside a living body. 
         [0032]    The light source apparatus  3  includes an endoscope information reading section  11 , an LED control section  12 , a light source unit  13  including a plurality of LEDs, and an optical system  14  including lenses  14   a  and  14   b.    
         [0033]    The endoscope information reading section  11  reads the endoscope information relating to the diameter size of the light guide  4  from the endoscope information storing section  5  in the endoscope  2  connected to the light source apparatus  3 , and outputs the read endoscope information to the LED control section  12 . 
         [0034]    Note that, in the present embodiment, although the endoscope information storing section  5  with the endoscope information relating to the diameter size of the light guide  4  stored therein is provided in the endoscope  2 , the endoscope information storing section  5  may be provided in the light source apparatus  3 . In this case, information relating to types of endoscopes  2  (endoscope ID) and endoscope information relating to diameter sizes of light guides  4  are stored in a storage section in the light source apparatus  3  in association with each other. When an endoscope  2  is connected to the light source apparatus  3 , the light source apparatus  3  reads information relating to the type of the connected endoscope  2  (endoscope ID) and outputs endoscope information relating to a diameter size of a corresponding light guide  4  to the LED control section  12 . 
         [0035]    The LED control section  12 , which serves as a light source control section, performs control to turn on or off the LEDs, which serve as a plurality of light sources in the light source unit  13 , based on the endoscope information inputted from the endoscope information reading section  11 . 
         [0036]    In the light source unit  13 , the plurality of LEDs which emit illuminating light of a same color, that is, illuminating light in a same wavelength band are arranged. Note that details of an arrangement of the plurality of LEDs will be described with reference to  FIG. 2 . The plurality of LEDs in the light source unit  13  are turned on/off according to the control by the LED control section  12 . Illuminating light from one or more LEDs turned on according to the control by the LED control section  12  enters the optical system  14 . 
         [0037]    The lenses  14   a  and  14   b  in the optical system  14  collect the illuminating light emitted from the light source unit  13  and makes the illuminating light enter the proximal end-side input end of the light guide  4 . As described above, the optical system  14  provides an in-light source light guiding channel that guides light emitted from the light source unit  13  to the proximal end-side input end of the light guide  4  in the endoscope  2 . The illuminating light that has entered the proximal end-side input end of the light guide  4  exits from the distal end-side output end and illuminates an object. 
         [0038]    Here, a detailed configuration of the light source unit  13  in the light source apparatus  3  configured as described above and a lighting state of the light source unit  13  will be described. 
         [0039]      FIG. 2  is a diagram for describing an example of a detailed configuration of a light source unit,  FIG. 3A  is a diagram for describing an example of a lighting state of a light source unit where a large-diameter light guide is connected thereto, and  FIG. 3B  is a diagram for describing an example of a lighting state of a light source unit where a small-diameter light guide is connected thereto. 
         [0040]    As illustrated in  FIG. 2 , the light source unit  13  includes an LED substrate  21 , and a plurality of LEDs  22  and  23  arranged on the LED substrate  21 . The LED  22 , which serves as a first light source group, is arranged in a substantial center of the LED substrate  21 , and the LEDs  23 , which serve as a second light source group, include six LEDs  23 , and are arranged on the LED substrate  21  substantially annularly with the LED  22  as a center. 
         [0041]    Illuminating light from the LED  22 , which serves as the first light source group, enters a vicinity of an optical axis (center axis) of the proximal end-side input end of the light guide  4 . Illuminating light from the LEDs  23 , which serve as the second light source group arranged in the periphery of the first light source group, enters a periphery of the optical axis (center axis) of the proximal end-side input end of the light guide  4  relative to the illuminating light from the LED  22 . Note that, although the first light source group includes one LED  22 , the first light source group may include two or more LEDs. Therefore, although only one LED  22  is provided here, the LED  22  is referred to as “first light source group”. 
         [0042]    The LED control section  12  is connected to the light source unit  13  via two control wires, i.e., a control wire A and a control wire B. For example, the control wire A is a control wire for controlling turning-on or off of the LED  22 , which serves as the first light source group, and the control wire B is a control wire for controlling turning-on or off of the LEDs  23 , which serve as the second light source group. 
         [0043]    The LED control section  12  performs control to turn on or off the LED  22 , which serves as the first light source group, and the LEDs  23 , which serve as the second light source group, via the control wire A and the control wire B based on the endoscope information read from the endoscope  2 . 
         [0044]    Where a large-diameter light guide  4   a  is connected as illustrated in  FIG. 3A , the LED control section  12  performs control to turn on the LED  22 , which serves as the first light source group, and the LEDs  23 , which serve as the second light source group. On the other hand, where a small-diameter light guide  4   b  is connected as illustrated in  FIG. 3B , the LED control section  12  performs control to turn on the LED  22 , which serves as the first light source group, and turn off the LEDs  23 , which serve as the second light source group, arranged in the periphery of the first light source group. 
         [0045]    As described above, where it is determined based on endoscope information read from the endoscope information storing section  5  that the small-diameter light guide  4   b  is connected, the LED control section  12  performs control to stop an output of the LEDs  23 , which serve as the second light source group. Note that, where it is determined that the small-diameter light guide  4   b  is connected, the LED control section  12  may perform control to decrease the output of the LEDs  23 , which serves as the second light source group, to be lower than an output of the first light source group. 
         [0046]    As described above, the light source apparatus  3  is configured to control to turn on or off the LED  22 , which serves as the first light source group, and the LEDs  23 , which serve as the second light source group, based on endoscope information relating to a diameter size of a light guide  4  in an endoscope  2  connected thereto. Consequently, the number of LEDs turned on according to the diameter size of the light guide  4  can be controlled, that is, the control to turn on the first light source group and the control to turn on the second light source group can be performed individually, enabling suppression of wasted light generation and temperature increase. 
         [0047]    Accordingly, a light source apparatus according to the present embodiment enables reduction of noise of a cooling fan due to heat generation. 
       Second Embodiment 
       [0048]    Next, a second embodiment will be described. 
         [0049]      FIG. 4  is a diagram illustrating a configuration of an endoscope system including a light source apparatus according to a second embodiment. Note that in  FIG. 4 , components that are the same as those in  FIG. 1  are provided with reference numerals that are the same as those in  FIG. 1 , and a description thereof will be omitted. 
         [0050]    As illustrated in  FIG. 4 , an endoscope system la includes an endoscope  2   a,  a light source apparatus  3   a  and a processor  30 . 
         [0051]    At a distal end of the endoscope  2   a,  a non-illustrated objective lens for forming an optical image of an illuminated object is provided. At a position where an image is formed via the objective lens, an image pickup device  6  such as a CCD is provided. The image pickup device  6  photoelectrically converts the formed optical image to generate an image pickup signal. The image pickup device  6  is connected to a processor  30  via a signal wire, and outputs the generated image pickup signal to the processor  30  via the signal. 
         [0052]    The processor  30  includes a brightness information calculating section  31 , and the image pickup signal from the image pickup device  6  is supplied to the brightness information calculating section  31 . 
         [0053]    The brightness information calculating section  31  calculates brightness information on the picked-up image from the image pickup signal supplied from the image pickup device  6 . Note that the brightness information is not limited to picked-up image information and may be, for example, numerical value data of luminance information. The brightness information calculating section  31  outputs the calculated brightness information to an LED control section  12   a  in the light source apparatus  3   a.    
         [0054]    The LED control section  12   a  performs control to turn on or off an LED  22 , which serves as a first light source group, and LEDs  23 , which serve as a second light source group, as well as light adjustment control for the LED  22  and the LEDs  23 , based on endoscope information from an endoscope information reading section  11  and the brightness information from the brightness information calculating section  31 . The rest of the configuration is similar to that of the first embodiment. 
         [0055]    Here, a detailed configuration of a light source unit  13  in the light source apparatus  3   a  configured as described above and a lighting state and light adjustment control for the light source unit  13  will be described. 
         [0056]      FIG. 5  is a diagram for describing an example of a detailed configuration of a light source unit,  FIG. 6  is a diagram for describing an example of a lighting state of a light source unit, and  FIG. 7  is a diagram illustrating an example of light adjustment control by a light source unit. 
         [0057]    As illustrated in  FIG. 5 , a configuration of the light source unit  13  is similar to that of the first embodiment. In the present embodiment, in addition to endoscope information, brightness information is inputted to the LED control section  12   a,  which serves as brightness information input means. Brightness information is information calculated from an image pickup signal obtained by the image pickup device  6  in the endoscope  2 , which has been supplied to the brightness information calculating section  31  in the processor  30 . 
         [0058]    The LED control section  12   a  performs control to turn on or off the LED  22 , which serves as the first light source group, and the LEDs  23 , which serve as the second light source group, and light adjustment control for the LED  22  and the LEDs  23 , based on the inputted endoscope information and brightness information. 
         [0059]    As illustrated in  FIG. 6 , in the case of the LEDs  23 , which serve as the second light source group arranged in the periphery of the LED  22 , which serves as the first light source group, also, illuminating light generated at a position close to a center of an LED substrate  12  enters a proximal end-side input end of a small-diameter light guide  4   b.  Accordingly, the LED control section  12   a  performs light adjustment control for the LED  22  (first light source group) and the LEDs  23  (second light source group) according to a light adjustment ratio calculated based on brightness information. In particular, the LED control section  12   a  controls a current value and a pulse width (duty ratio) of each of the current supplied to the LED  22  (first light source group) and the current supplied to the LEDs  23  (second light source group), according to the light adjustment ratio. 
         [0060]    As illustrated in  FIG. 7 , the LED control section  12   a  controls the current value and the duty ratio of each of the current supplied to the LED  22  (first light source group) and the current supplied to the LEDs  23  (second light source group) based on brightness information. For example, in the case of a light adjustment of 20%, the LED control section  12   a  controls the current value of the current supplied to the LED  22  (first light source group) to 50% and controls the duty ratio of the same to 30%, and controls the current value of the current supplied to the LEDs  23  (second light source group) to 0% and the duty ratio of the same to 0%. Also, for example, in the case of a light adjustment of 100%, the LED control section  12   a  controls the current value of the current supplied to the LED  22  (first light source group) to 100% and the duty ratio of the same to 100%, and the current value of the current supplied to the LEDs  23  (second light source group) to 80% and the duty ratio of the same to 70%. 
         [0061]    As described above, when the LED control section  12   a  reduces illuminating light emitted from the light source unit  13  based on brightness information, the LED control section  12   a  performs control to decrease an output of the LEDs  23 , which serve as the second light source group, in preference to the LED  22 , which is the first light source group. 
         [0062]    As described above, the light source apparatus  3   a  according to the present embodiment is configured to perform turning-on and light adjustment control for the first light source group and the second light source group based on brightness information in addition to endoscope information relating to a diameter size of a light guide  4 . Consequently, the lighting and light adjustment control for the first light source group and the lighting and light adjustment control for the second light source group can be performed individually, enabling suppression of wasted light generation and temperature increase. 
         [0063]    Accordingly, as with the first embodiment, a light source apparatus according to the present embodiment enables reduction of noise of a cooling fan due to heat generation. 
       Modification 
       [0064]    Light source apparatuses according to embodiments of the present invention are not limited to the light source apparatuses  3  and  3   a  according to the above-described first and second embodiments. For example, it is not necessary that an arrangement of an LED  22 , which serves as a first light source group, and LEDs  23 , which serve as a second light source group, be the arrangement in  FIG. 2 . 
         [0065]      FIGS. 8A ,  8 B and  8 C are diagrams each illustrating an example of another arrangement of LEDs. 
         [0066]    A light source unit  13   a,  which is illustrated in  FIG. 8A , includes five LEDs  22 , which serve as a first light source group arranged in a substantial center of an LED substrate  21  and above, below and on the left and right of the substantial center, and eight LEDs  23 , which serve as a second light source group arranged in a substantially rhombic shape in the periphery of the first light source group. 
         [0067]    A light source unit  13   b,  which is illustrated in  FIG. 8B , includes one LED  22 , which serves as a first light source group arranged at a substantial center of an LED substrate  21 , and eight LEDs  23 , which serve as a second light source group arranged in a substantially quadrangular shape in the periphery of the first light source group. 
         [0068]    A light source unit  13 , which is illustrated in  FIG. 8C , includes two LEDs  22 , which serve as a first light source group arranged on the left and right of a substantial center of an LED substrate  21 , and eight LEDs  23 , which serve as a second light source group arranged in a substantially oval shape in the periphery of the first light source group. 
         [0069]    As described above, the first and second light source group arrangement is not limited to the first and second light source group arrangement illustrated in  FIG. 2 . 
         [0070]    Also, although the light source units  13  according to the first and second embodiments each have a configuration including an LED  22 , which serves as a first light source group, and LEDs  23 , which serve as a second light source group, a configuration including three or more light source groups may be employed. 
         [0071]      FIG. 9  is a diagram illustrating an example of a light source unit including three light source groups. 
         [0072]    As illustrated in  FIG. 9 , an arrangement of LEDs in a light source unit  13   d  is similar to that in  FIG. 8A . 
         [0073]    The light source unit  13   d  includes one LED  22 , which serves as a first light source group arranged in a substantial center of an LED substrate  21 , four LEDs  23 , which serve as a second light source group arranged above, below and on the left and right of the first light source group, and eight LEDs  24 , which serve as a third light source group arranged in a substantially rhombic shape in the periphery of the second light source group. 
         [0074]    In such light source unit  13   d  including three light source groups (in one including three or more light source groups as well), the first light source group, the second light source group and the third light source group are arranged in this order from a center of an optical axis, in other words, a center of the LED substrate  21 . Also, where control for three light source groups is performed, a control wire C is provided between the LED control section  12  and the light source unit  13  in addition to the control wire A and the control wire B described above, control to turn on and off the LEDs  24 , which serve as the third light source group, is performed using the control wire C. 
         [0075]    Furthermore, although the light source apparatuses  3  according to the first and second embodiments each have a configuration including one light source unit  13 , a configuration including two or more light source units may be employed. 
         [0076]      FIG. 10  is a diagram for describing an example of a light source apparatus including a plurality of light source units. 
         [0077]    As illustrated in  FIG. 10 , a light source apparatus  3  includes a light source unit  13   e  in addition to a light source unit  13 . The light source unit  13   e,  which has a configuration similar to that of the light source unit  13 , includes an LED  22   a,  which serves as a first light source group, and LEDs  23   a  which serve as a second light source group, on an LED substrate  21   a.  Although these LED  22   a  and LEDs  23   a  emit illuminating light in a same wavelength band, an LED  22   a  and LEDs  23   a  emit illuminating light in different wavelength bands from those of LED  22  and LED  23 . 
         [0078]    Also, an optical system  14  includes a lens  14   c  that collects illuminating light from the light source unit  13   e  and a dichroic filter  32  that combines an optical path of illuminating light from the light source unit  13  and an optical path of illuminating light from the light source unit  13   e,  in addition to lenses  14   a  and  14   b.    
         [0079]    The dichroic filter  32  transmits illuminating light emitted from the light source unit  13  and reflects illuminating light emitted from the light source unit  13   e , whereby the optical path of the illuminating light from the light source unit  13  and the optical path of the illuminating light from the light source unit  13   e  are combined. 
         [0080]    As described above, where a plurality of light source units  13  and  13   e  are provided, it is only necessary to change a relevant optical path using, e.g., a dichroic filter  32 . 
         [0081]    The present invention is not limited to the above-described embodiments and modification, and various variations, alterations and the like are possible without departing from the spirit of the present invention.