JP4575565B2 - Endoscope light source unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light source for supplying irradiation light to an observation site when observing a body cavity of a patient with an endoscope.
[0002]
[Prior art]
Conventionally, a xenon lamp, a halogen lamp, a metal halide lamp, or the like is used as a light source provided in a light source device connected to a fiberscope or a processor connected to an electronic endoscope. When these lamps are used as a light source, there are problems such as an adverse effect due to noise caused by the discharge of the lamp and a problem that a predetermined circuit block for controlling the discharge tube is required and the entire light source device is enlarged. In order to solve such a problem, Japanese Patent Laid-Open No. 11-216114 proposes a light source device using a white LED as a light source.
[0003]
[Problems to be solved by the invention]
Since the amount of light of the white LED alone is lower than that of the above xenon lamp or the like, a plurality of white LEDs must be prepared in order to supply sufficient irradiation light to the observation site. On the other hand, the light emitted from the white LED is parallel light. Therefore, in the light source device disclosed in the publication, a condensing lens for condensing light emitted from the plurality of white LEDs to the incident end of the light guide is interposed. However, since a predetermined distance must be secured between the white LED and the light guide, there is a problem that the entire light source device cannot be reduced in size.
[0004]
In addition, the publication discloses a configuration in which a plurality of white LEDs are arranged on a curved mounting board as an example in which no condensing lens is interposed. In this configuration, the center of curvature of the curved surface of the mounting substrate must coincide with the incident end of the light guide in order to collect the emitted light of each white LED to the incident end of the light guide. That is, accuracy is required for the curved surface of the mounting substrate and the mounting angle of the white LED. Therefore, there exists a problem that manufacture is difficult.
[0005]
An object of the present invention is to solve the above problems, and to provide a light source unit for an endoscope that can be easily manufactured and can save space.
[0006]
[Means for Solving the Problems]
An endoscope light source unit according to the present invention is a light source unit that supplies a light source of irradiation light that irradiates an observation object via a light guide provided in a scope of an endoscope, and includes a plurality of light emitting elements and A first light emitting means having a planar holding member for holding a plurality of light emitting elements; and a reflecting member having a concave curved surface as a reflecting surface, wherein the reflecting member has a concave curved surface for emitting light from the plurality of light emitting elements. The light guide is provided so as to be incident on the holding member, and the light guide is provided so that the incident end surface thereof faces the concave curved surface.
[0007]
The concave curved surface of the reflecting member is, for example, a paraboloid, and the light guide is preferably provided so that the central axis of the paraboloid intersects the incident end face, and more preferably the incident end face is located near the focal point of the paraboloid. It is arranged to do.
[0008]
Preferably, the parabolic surface includes second light emitting means arranged so that the emitted light is incident on the incident end face of the light guide, and more preferably, the second light emitting means is the first light emitting element on the parabolic surface. The second light emitting means is preferably arranged at a position where the central axis of the paraboloid intersects with the paraboloid. It has an element.
[0009]
Preferably, the holding member is provided at a position farther from the paraboloid than the focal point of the paraboloid.
[0010]
The light guide is preferably arranged so as to pass through a hole formed at a position where the central axis of the paraboloid intersects in the holding member.
[0011]
The concave curved surface of the reflecting member may be, for example, a part of a spherical surface or a part of an elliptical curved surface.
[0012]
As described above, according to the present invention, an optical element such as a condensing lens is provided on the optical path of the light emitted from the light emitting element so as to collect the light emitted from the light emitting element of the first light emitting unit on the incident end surface of the light guide. There is no need to intervene the system. Therefore, space saving of the light source unit can be achieved.
[0013]
Further, since the light emitting element is held by the planar holding member in the first light emitting means, the manufacture is easy.
[0014]
By disposing the second light emitting means on the parabolic surface of the reflecting member at a position facing the incident end surface of the light guide, the amount of light incident on the light guide is increased. Furthermore, if at least one light emitting element is disposed at a position where the central axis of the paraboloid intersects on the paraboloid, the amount of light can be increased more effectively.
[0015]
The holding member is provided at a position farther from the paraboloid than the focal point of the parabolic mirror, or the light guide is arranged to pass through a hole formed at a position where the central axis of the paraboloid intersects the holding member. By doing so, since the light beam incident on the light guide is not shielded by the holding member, the light collection efficiency is increased.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an electronic endoscope to which the first embodiment according to the present invention is applied. The scope 10 has a flexible conduit (flexible tube) and is detachably connected to the image signal processing unit 20.
An imaging sensor 11 is provided on the distal end side of the scope 10. The imaging sensor 11 includes an objective lens 110, a CCD image sensor 111 including a color chip filter, and a diaphragm 112 interposed between the objective lens 110 and the CCD image sensor 111. A light guide 12 is inserted into the scope 10, and its emission end extends to the tip of the scope 10.
[0017]
The system controller 21 of the image signal processing unit 20 is a microcomputer that controls the electronic endoscope as a whole. That is, the system controller 21 is a central processing unit (CPU), a program for executing various routines, a read only memory (ROM) for storing constants, and a write / readable memory (temporarily storing data). RAM).
[0018]
When the scope 10 is connected to the image signal processing unit 20, the image sensor 11 is connected to the video signal processing circuit 22 via a CCD circuit (not shown) provided in the scope 10. Further, the incident end of the light guide 12 is optically connected to a light source unit 23 provided in the image signal processing unit 20.
[0019]
The image signal processing unit 20 is provided with a front panel 24, and the front panel 24 is provided with various indicator lamps and various switches. A main power source (not shown) of the image signal processing unit 20 is switched on / off by a power switch (SW) 241, and lighting of the light source unit 23 is controlled by a lighting switch (SW) 242.
[0020]
Based on the signal from the lighting SW 242, the system controller 21 outputs a control signal to the lamp power circuit 25. In accordance with a control signal from the system controller 21, the power supply to the light source unit 23 is appropriately controlled by the lamp power circuit 25. When the power supply to the light source unit 23 is started, white light is emitted as will be described later, and the object is irradiated through the light guide 12. The lamp power circuit 25 is connected to a commercial power source via a plug (not shown).
[0021]
The image signal read from the image sensor 11 is sent to the video signal processing circuit 22 via a transmission buffer (not shown) in the scope 10. In the video signal processing circuit 22, processing such as sampling, clamping, blanking, and amplification is performed in the process circuit block 221 to generate a luminance signal (Y) and color difference signals (RY, BY). The luminance signal and the color difference signal are each subjected to predetermined image processing such as gamma correction, converted into a digital image signal by the A / D converter 222, and stored in the image memory 224, respectively.
[0022]
The digitized luminance signal and color difference signal are read from the image memory 224 and subjected to processing such as enlargement, reduction, noise reduction, etc. in the image signal processing circuit 223, and then an analog signal is output from the D / A converter 225. Is converted to The luminance signal and the analog signal of the color difference signal are decoded by the RGB decoder 227 into RGB video signals corresponding to the three primary colors red (R), green (G), and blue (B), while the encoder 226 performs luminance. The S video signal (Y / C) is generated by encoding the signal (Y) and the color signal (C). These RGB video signal and S video signal are added with a horizontal synchronizing signal and a vertical synchronizing signal, and sent to an external TV monitor (not shown) connected to the image signal processing unit 20. The TV monitor displays an image on the screen based on the transmitted S video signal or RGB signal.
[0023]
Note that the timing controller 26 controls conversion timing, generation of a horizontal synchronization signal, vertical synchronization signal, and the like in the A / D converter 222 and the D / A converter 225.
[0024]
FIG. 2 is a partial cross-sectional view showing the light source unit 23 in an enlarged manner from the side. A plurality of white LEDs 232 (light emitting elements) are attached to the flat portion 231A of the flat holding plate 231 by soldering. The parabolic mirror 233 is disposed to face the holding plate 231 so that the light emitted from the plurality of white LEDs 232 is incident on a concave curved parabolic surface 233A that is a reflecting surface. FIG. 3 is a front view showing the holding plate 231 from the parabolic mirror 233 side. Note that the white LED 232 is omitted in FIG. 3 in order to clearly show the configuration of the holding plate 231, but actually, it is attached over the entire area of the flat portion 231 </ b> A. As shown in FIG. 3, the holding plate 231 has a disk shape, and a hole 231B is formed at the center thereof. The holding plate 231 and the parabolic mirror 233 are arranged so that the center of the hole 231B of the holding plate 231 is positioned on the central axis R of the parabolic surface 233A of the parabolic mirror 233.
[0025]
As shown in FIG. 2, the light guide 12 is inserted into the hole 231B of the holding plate 231 so that the incident end faces the parabolic mirror 233 side. The light guide 12 is arranged such that the central axis R of the paraboloid 233A intersects the incident end face thereof, and the incident end face is positioned in the vicinity of the focal point of the parabolic mirror 233. In the first embodiment, the incident end surface of the light guide 12 is located closer to the parabolic mirror 233 than the focal point of the parabolic mirror 233, but the present invention is not limited to this. It may be located on the holding plate 231 side. In other words, the incident end surface of the light guide 12 has a predetermined range including the focal point of the parabolic mirror 233 along the central axis R of the parabolic surface 233A so as not to reduce the light collection efficiency of the emitted light of the white LED 232. It suffices if it is positioned within.
[0026]
The flat portion 231A of the holding plate 231 has a diameter that is substantially the same as the diameter of the opening of the parabolic surface 233A of the parabolic mirror 233. Accordingly, all of the light emitted from the white LED 232 attached to the entire region except the hole 231B in the flat portion 231A is reflected by the parabolic surface 233A of the parabolic mirror 233 and guided to the incident end of the light guide 12.
[0027]
As described above, in the electronic endoscope to which the first embodiment is applied, image processing is performed by the color simultaneous method, but the present invention is not limited to this. For example, instead of the white LED 232, RGB three-color LEDs are arranged on the holding plate 231 so that the light quantity distribution is uniform, each LED is sequentially pulsed for each RGB, and a monochrome CCD image sensor is used to generate an image signal. It is also possible to perform image processing by the processing unit 20 in a frame sequential manner. Further, the white LED 232 is disposed on the holding plate 231, and an RGB rotation filter that rotates at a predetermined rotation frequency is provided between the parabolic mirror 233 and the incident end of the light guide 12. It is also possible to perform image processing by the method.
[0028]
FIG. 4 is a partial sectional view showing the light source unit 27 to which the second embodiment according to the present invention is applied from the side, and the same members as those of the light source unit 23 of the first embodiment are denoted by the same reference numerals. ing. The relative positions of the holding plate 231, the light guide 12, and the paraboloid 237 </ b> A that is the reflecting surface of the parabolic mirror 237 in the light source unit 27 of the second embodiment are the same as those in the first embodiment. As described above, since the hole 231 </ b> B through which the light guide 12 is inserted is formed at the center of the holding plate 231, there is an area where the white LED 232 cannot be attached to the flat portion 231 </ b> A of the holding plate 231. That is, the parabolic surface 237A of the parabolic mirror 237 has a region where the light emitted from the white LED 232 does not enter. In the second embodiment, the white LED 238 (second light emitting means) is disposed at a position facing the incident end surface of the light guide 12 in the region where the light emitted from the white LED 232 on the paraboloid 237A is not incident. FIG. 5 is a front view showing the parabolic mirror 237 of FIG. 4 from the holding plate 231 side. As apparent from FIGS. 4 and 5, the white LED 238 is provided to emit toward the incident end face of the light guide 12 at a position where the central axis R of the paraboloid 237A intersects the paraboloid 237A.
[0029]
FIG. 6 is a partial cross-sectional view showing a light source unit according to a modification of the second embodiment from the side, and FIG. 7 is a front view showing the parabolic mirror 237 from the holding plate 231 side. The relative positions of the holding plate 231, the light guide 12, and the paraboloid 237A of the parabolic mirror 237 are the same as those in the first embodiment, and the configuration in which the white LEDs 232 and 238 are disposed is also the same.
In this modification, a plurality of white LEDs 239 are arranged around the white LED 238 over substantially the entire region where the light emitted from the white LED 232 on the paraboloid 237A is not incident.
[0030]
In the first and second embodiments, the parabolic mirror 233 whose reflecting surface is a parabolic surface is used as the reflecting member. However, the present invention is not limited to this, and the reflecting surface is a part of a spherical surface or an elliptic curved surface. A part of the reflective member may be used.
[0031]
The light source units 23 and 27 of the first and second embodiments are configured to be provided in the processor of the electronic endoscope. However, the present invention is not limited to this and can be applied to a light source device to which a fiberscope is connected.
[0032]
【The invention's effect】
As described above, according to the present invention, a light source unit that is easy to manufacture and compact can be obtained. That is, in the light source unit, a plurality of white LEDs are attached to a planar holding member instead of a curved holding member, so that the manufacture thereof is easy, and automation of assembly can be easily handled. Further, since the light emitted from the white LED is reflected by the reflecting surface which is a concave curved surface and is incident on the light guide, an expensive condensing lens is not required, and the manufacturing cost can be reduced and the space can be saved.
[Brief description of the drawings]
FIG. 1 is a block diagram of an electronic endoscope processor including a light source unit to which a first embodiment according to the present invention is applied.
FIG. 2 is a partial cross-sectional view showing an enlarged view from the side of the light source unit of the first embodiment.
FIG. 3 is a front view showing a holding plate to which a white LED is attached from the radiation mirror side.
FIG. 4 is an enlarged view showing a light source unit to which a second embodiment according to the present invention is applied from the side.
5 is a front view showing a paraboloid of the parabolic mirror of FIG. 4. FIG.
FIG. 6 is an enlarged view showing a modification of the light source unit of the second embodiment from the side.
7 is a front view showing a paraboloid of the parabolic mirror of FIG. 6. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Scope 12 Light guide 20 Image signal processing unit 21 System controller 22 Video signal processing circuit 23, 27 Light source unit 24 Front panel 25 Lamp power supply circuit 231 Holding plate 232 White LED
233, 237 Parabolic mirror 238, 239 White LED

Claims (10)

A light source unit that supplies a light source of irradiation light that irradiates an object to be observed through a light guide provided in an endoscope scope,
A first light emitting means having a plurality of light emitting elements and a planar holding member for holding the plurality of light emitting elements;
A reflective member having a concave curved surface that is a reflective surface;
The reflecting member, the plurality of Rutotomoni emitted light of the light emitting element is provided opposite to the holding member so as to be incident on the concave curved surface, wherein the light guide is provided such that the incident end surface is opposed to the concave curved surface It is,
The plane of the holding member is orthogonal to the central axis of the concave curved surface, and a hole is provided in the holding member at a position where the central axis intersects the plane, and the light guide is inserted through the hole and the incident end surface thereof is An endoscope light source unit, which is disposed so as to be orthogonal to the central axis in the vicinity of the focal point of the concave curved surface . 2. The endoscope light source unit according to claim 1 , further comprising: a second light emitting unit disposed on the concave curved surface so that emitted light is incident on an incident end surface of the light guide. 3. The endoscope light source unit according to claim 2 , wherein the second light emitting unit is disposed in a region where the light emitted from the first light emitting unit is not incident on the concave curved surface . It said second light emitting means for endoscope according to claim 3, characterized in that it comprises at least one light-emitting element in which the central axis of the concave curved surface in the concave curved surface is disposed at the intersection Light source unit. The holding member, than the focal point of the concave curved surface, an endoscope light source unit according to claim 1, characterized in that provided at a position which is distant from the concave curved surface. The endoscope light source unit according to claim 5, wherein the hole is formed at a center of the plane. The endoscope light source unit according to claim 6, wherein the holding member has a disk shape. The light source unit for an endoscope according to any one of claims 1 to 7, wherein the concave curved surface of the reflecting member is a paraboloid. The endoscope light source unit according to claim 1 , wherein the concave curved surface of the reflecting member is a part of a spherical surface. The endoscope light source unit according to claim 1 , wherein the concave curved surface of the reflecting member is a part of an elliptical curved surface.

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