Light source apparatus

A light source apparatus includes: 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 a proximal end-side input end of a light guiding channel in an endoscope; and a light source control section that, based on endoscope information from an 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.

BACKGROUND OF THE INVENTION

1. Field of the Invention

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.

2. Description of the Related Art

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. 11Ais a diagram illustrating a configuration of a conventional light source apparatus where a large-diameter light guide is connected thereto, andFIG. 11Bis a diagram illustrating a configuration of a conventional light source apparatus where a small-diameter light guide is connected thereto.

As illustrated inFIG. 11A, a conventional light source apparatus100includes a light source101such as a xenon lamp, a light source group control section102that performs turning-on control of the light source101, and an optical system103including a plurality of lenses103aand103b, the optical system103collecting illuminating light from the light source101. Such light source apparatus100is attachable/detachable to/from an endoscope, and a different type of endoscope is connected to the light source apparatus100depending on, e.g., the procedure, the observed site and/or the state of the patient.

In the example inFIG. 11A, an endoscope including a large-diameter light guide104is connected to the light source apparatus100. The illuminating light from the light source101, which has been collected by the optical system103, enters an end face on the proximal end side of the large-diameter light guide104.

On the other hand, as illustrated inFIG. 11B, where an endoscope including a small-diameter light guide105is connected to the light source apparatus100, the illuminating light from the light source101, which has been collected by the optical system103, does not entirely enter an end face on the proximal end side of the small-diameter light guide105.

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).

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

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.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is a diagram illustrating a configuration of an endoscope system including a light source apparatus according to a first embodiment.

As illustrated inFIG. 1, an endoscope system1includes an endoscope2that picks up an image of an object inside a living body, and a light source apparatus3that supplies illuminating light for illuminating the object to the endoscope2.

The endoscope2can be attached/detached to/from the light source apparatus3via, e.g., a non-illustrated connector. The endoscope2includes, in its inside, a light guide4inserted from the proximal end side to the distal end side, the light guide4guiding illuminating light from the light source apparatus3, and an endoscope information storing section5with diameter information relating to a diameter size of the light guide4(hereinafter also referred to as “endoscope information”) stored therein.

An end face on the light entrance side (hereinafter also referred to as “proximal end-side input end”) of the light guide4is arranged on the proximal end side of the endoscope2, and an end face on the light exit side (hereinafter also referred to as “distal end-side output end”) of the light guide4is arranged on the distal end side of the endoscope2. Where the endoscope2is connected to the light source apparatus3, the proximal end-side input end of the light guide4is connected to the light source apparatus3. The light guide4, 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 apparatus3enters the proximal end-side input end and then exits from the distal end-side output end of the light guide4, and illuminates an object inside a living body.

The light source apparatus3includes an endoscope information reading section11, an LED control section12, a light source unit13including a plurality of LEDs, and an optical system14including lenses14aand14b.

The endoscope information reading section11reads the endoscope information relating to the diameter size of the light guide4from the endoscope information storing section5in the endoscope2connected to the light source apparatus3, and outputs the read endoscope information to the LED control section12.

Note that, in the present embodiment, although the endoscope information storing section5with the endoscope information relating to the diameter size of the light guide4stored therein is provided in the endoscope2, the endoscope information storing section5may be provided in the light source apparatus3. In this case, information relating to types of endoscopes2(endoscope ID) and endoscope information relating to diameter sizes of light guides4are stored in a storage section in the light source apparatus3in association with each other. When an endoscope2is connected to the light source apparatus3, the light source apparatus3reads information relating to the type of the connected endoscope2(endoscope ID) and outputs endoscope information relating to a diameter size of a corresponding light guide4to the LED control section12.

The LED control section12, 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 unit13, based on the endoscope information inputted from the endoscope information reading section11.

In the light source unit13, 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 toFIG. 2. The plurality of LEDs in the light source unit13are turned on/off according to the control by the LED control section12. Illuminating light from one or more LEDs turned on according to the control by the LED control section12enters the optical system14.

The lenses14aand14bin the optical system14collect the illuminating light emitted from the light source unit13and makes the illuminating light enter the proximal end-side input end of the light guide4. As described above, the optical system14provides an in-light source light guiding channel that guides light emitted from the light source unit13to the proximal end-side input end of the light guide4in the endoscope2. The illuminating light that has entered the proximal end-side input end of the light guide4exits from the distal end-side output end and illuminates an object.

Here, a detailed configuration of the light source unit13in the light source apparatus3configured as described above and a lighting state of the light source unit13will be described.

FIG. 2is a diagram for describing an example of a detailed configuration of a light source unit,FIG. 3Ais a diagram for describing an example of a lighting state of a light source unit where a large-diameter light guide is connected thereto, andFIG. 3Bis a diagram for describing an example of a lighting state of a light source unit where a small-diameter light guide is connected thereto.

As illustrated inFIG. 2, the light source unit13includes an LED substrate21, and a plurality of LEDs22and23arranged on the LED substrate21. The LED22, which serves as a first light source group, is arranged in a substantial center of the LED substrate21, and the LEDs23, which serve as a second light source group, include six LEDs23, and are arranged on the LED substrate21substantially annularly with the LED22as a center.

Illuminating light from the LED22, 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 guide4. Illuminating light from the LEDs23, 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 guide4relative to the illuminating light from the LED22. Note that, although the first light source group includes one LED22, the first light source group may include two or more LEDs. Therefore, although only one LED22is provided here, the LED22is referred to as “first light source group”.

The LED control section12is connected to the light source unit13via 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 LED22, 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 LEDs23, which serve as the second light source group.

The LED control section12performs control to turn on or off the LED22, which serves as the first light source group, and the LEDs23, 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 endoscope2.

Where a large-diameter light guide4ais connected as illustrated inFIG. 3A, the LED control section12performs control to turn on the LED22, which serves as the first light source group, and the LEDs23, which serve as the second light source group. On the other hand, where a small-diameter light guide4bis connected as illustrated inFIG. 3B, the LED control section12performs control to turn on the LED22, which serves as the first light source group, and turn off the LEDs23, which serve as the second light source group, arranged in the periphery of the first light source group.

As described above, where it is determined based on endoscope information read from the endoscope information storing section5that the small-diameter light guide4bis connected, the LED control section12performs control to stop an output of the LEDs23, which serve as the second light source group. Note that, where it is determined that the small-diameter light guide4bis connected, the LED control section12may perform control to decrease the output of the LEDs23, which serves as the second light source group, to be lower than an output of the first light source group.

As described above, the light source apparatus3is configured to control to turn on or off the LED22, which serves as the first light source group, and the LEDs23, which serve as the second light source group, based on endoscope information relating to a diameter size of a light guide4in an endoscope2connected thereto. Consequently, the number of LEDs turned on according to the diameter size of the light guide4can 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.

Accordingly, a light source apparatus according to the present embodiment enables reduction of noise of a cooling fan due to heat generation.

Next, a second embodiment will be described.

FIG. 4is a diagram illustrating a configuration of an endoscope system including a light source apparatus according to a second embodiment. Note that inFIG. 4, components that are the same as those inFIG. 1are provided with reference numerals that are the same as those inFIG. 1, and a description thereof will be omitted.

As illustrated inFIG. 4, an endoscope system la includes an endoscope2a, a light source apparatus3aand a processor30.

At a distal end of the endoscope2a, 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 device6such as a CCD is provided. The image pickup device6photoelectrically converts the formed optical image to generate an image pickup signal. The image pickup device6is connected to a processor30via a signal wire, and outputs the generated image pickup signal to the processor30via the signal wire.

The processor30includes a brightness information calculating section31, and the image pickup signal from the image pickup device6is supplied to the brightness information calculating section31.

The brightness information calculating section31calculates brightness information on the picked-up image from the image pickup signal supplied from the image pickup device6. 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 section31outputs the calculated brightness information to an LED control section12ain the light source apparatus3a.

The LED control section12aperforms control to turn on or off an LED22, which serves as a first light source group, and LEDs23, which serve as a second light source group, as well as light adjustment control for the LED22and the LEDs23, based on endoscope information from an endoscope information reading section11and the brightness information from the brightness information calculating section31. The rest of the configuration is similar to that of the first embodiment.

Here, a detailed configuration of a light source unit13in the light source apparatus3aconfigured as described above and a lighting state and light adjustment control for the light source unit13will be described.

FIG. 5is a diagram for describing an example of a detailed configuration of a light source unit,FIG. 6is a diagram for describing an example of a lighting state of a light source unit, andFIG. 7is a diagram illustrating an example of light adjustment control by a light source unit.

As illustrated inFIG. 5, a configuration of the light source unit13is similar to that of the first embodiment. In the present embodiment, in addition to endoscope information, brightness information is inputted to the LED control section12a, which serves as brightness information input means. Brightness information is information calculated from an image pickup signal obtained by the image pickup device6in the endoscope2a, which has been supplied to the brightness information calculating section31in the processor30.

The LED control section12aperforms control to turn on or off the LED22, which serves as the first light source group, and the LEDs23, which serve as the second light source group, and light adjustment control for the LED22and the LEDs23, based on the inputted endoscope information and brightness information.

As illustrated inFIG. 6, in the case of the LEDs23, which serve as the second light source group arranged in the periphery of the LED22, which serves as the first light source group, also, illuminating light generated at a position close to a center of an LED substrate12enters a proximal end-side input end of a small-diameter light guide4b. Accordingly, the LED control section12aperforms light adjustment control for the LED22(first light source group) and the LEDs23(second light source group) according to a light adjustment ratio calculated based on brightness information. In particular, the LED control section12acontrols a current value and a pulse width (duty ratio) of each of the current supplied to the LED22(first light source group) and the current supplied to the LEDs23(second light source group), according to the light adjustment ratio.

As illustrated inFIG. 7, the LED control section12acontrols the current value and the duty ratio of each of the current supplied to the LED22(first light source group) and the current supplied to the LEDs23(second light source group) based on brightness information. For example, in the case of a light adjustment ratio of 20%, the LED control section12acontrols the current value of the current supplied to the LED22(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 LEDs23(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 ratio of 100%, the LED control section12acontrols the current value of the current supplied to the LED22(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 LEDs23(second light source group) to 80% and the duty ratio of the same to 70%.

As described above, when the LED control section12areduces illuminating light emitted from the light source unit13based on brightness information, the LED control section12aperforms control to decrease an output of the LEDs23, which serve as the second light source group, in preference to the LED22, which is the first light source group.

As described above, the light source apparatus3aaccording 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 guide4. 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.

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.

Light source apparatuses according to embodiments of the present invention are not limited to the light source apparatuses3and3aaccording to the above-described first and second embodiments. For example, it is not necessary that an arrangement of an LED22, which serves as a first light source group, and LEDs23, which serve as a second light source group, be the arrangement inFIG. 2.

FIGS. 8A,8B and8C are diagrams each illustrating an example of another arrangement of LEDs.

A light source unit13a, which is illustrated inFIG. 8A, includes five LEDs22, which serve as a first light source group arranged in a substantial center of an LED substrate21and above, below and on the left and right of the substantial center, and eight LEDs23, which serve as a second light source group arranged in a substantially rhombic shape in the periphery of the first light source group.

A light source unit13b, which is illustrated inFIG. 8B, includes one LED22, which serves as a first light source group arranged at a substantial center of an LED substrate21, and eight LEDs23, which serve as a second light source group arranged in a substantially quadrangular shape in the periphery of the first light source group.

A light source unit13, which is illustrated inFIG. 8C, includes two LEDs22, which serve as a first light source group arranged on the left and right of a substantial center of an LED substrate21, and eight LEDs23, which serve as a second light source group arranged in a substantially oval shape in the periphery of the first light source group.

As described above, the first and second light source group arrangement is not limited to the first and second light source group arrangement illustrated inFIG. 2.

Also, although the light source units13according to the first and second embodiments each have a configuration including an LED22, which serves as a first light source group, and LEDs23, which serve as a second light source group, a configuration including three or more light source groups may be employed.

FIG. 9is a diagram illustrating an example of a light source unit including three light source groups.

As illustrated inFIG. 9, an arrangement of LEDs in a light source unit13dis similar to that inFIG. 8A.

The light source unit13dincludes one LED22, which serves as a first light source group arranged in a substantial center of an LED substrate21, four LEDs23, 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 LEDs24, which serve as a third light source group arranged in a substantially rhombic shape in the periphery of the second light source group.

In such light source unit13dincluding 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 substrate21. Also, where control for three light source groups is performed, a control wire C is provided between the LED control section12and the light source unit13in addition to the control wire A and the control wire B described above, control to turn on and off the LEDs24, which serve as the third light source group, is performed using the control wire C.

Furthermore, although the light source apparatuses3according to the first and second embodiments each have a configuration including one light source unit13, a configuration including two or more light source units may be employed.

FIG. 10is a diagram for describing an example of a light source apparatus including a plurality of light source units.

As illustrated inFIG. 10, a light source apparatus3includes a light source unit13ein addition to a light source unit13. The light source unit13e, which has a configuration similar to that of the light source unit13, includes an LED22a, which serves as a first light source group, and LEDs23awhich serve as a second light source group, on an LED substrate21a. Although these LED22aand LEDs23aemit illuminating light in a same wavelength band, an LED22aand LEDs23aemit illuminating light in different wavelength bands from those of LED22and LED23.

Also, an optical system14includes a lens14cthat collects illuminating light from the light source unit13eand a dichroic filter32that combines an optical path of illuminating light from the light source unit13and an optical path of illuminating light from the light source unit13e, in addition to lenses14aand14b.

The dichroic filter32transmits illuminating light emitted from the light source unit13and reflects illuminating light emitted from the light source unit13e, whereby the optical path of the illuminating light from the light source unit13and the optical path of the illuminating light from the light source unit13eare combined.

As described above, where a plurality of light source units13and13eare provided, it is only necessary to change a relevant optical path using, e.g., a dichroic filter32.

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.