JP2015029756A - Light source device for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device for endoscope which is compatible with a general-purpose scope and is capable of adjusting the illumination range (light distribution).SOLUTION: A light source device for endoscope comprises: a lamp for emitting illumination light; a luminous flux diameter adjustment part for adjusting the luminous flux diameter of the illumination light emitted from the lamp; a holding part for holding a light guide of an endoscope; and a condenser lens which condenses the illumination light of which luminous flux diameter is adjusted by the luminous flux diameter adjustment part, and lets the condensed illumination light enter the incident end of the light guide held by the holding part.

Description

  The present invention relates to an endoscope light source device that supplies illumination light for illuminating a subject such as a lesion to an endoscope.

  An endoscope system for observing a subject such as a lesion is used in a medical field. The endoscope system includes a light source device that illuminates a body cavity where natural light does not reach through a light guide such as an electronic scope or a fiberscope. A specific configuration of this type of light source device is described in Patent Document 1, for example.

  The light source device described in Patent Document 1 causes illumination light emitted from a lamp to enter a ride guide via a converging lens. The light source device described in Patent Document 1 slides the converging lens in the optical axis direction, and the amount of light incident on the light guide that forms the illumination optical system for the wide area and the amount of light incident on the ride guide that forms the illumination optical system for the central area. By changing the balance, the substantial illumination range (light distribution) to the subject is changed.

JP 2009-22375 A

  However, the light source device described in Patent Document 1 only supports a special scope including a wide-area illumination optical system and a central-area illumination optical system. Therefore, in the present invention, an endoscope light source device corresponding to a general-purpose scope, which can change an illumination range (light distribution) is provided.

  An endoscope light source device according to an embodiment of the present invention is connected to an endoscope light guide, and adjusts a lamp that emits illumination light and a light beam diameter of illumination light emitted from the lamp. A light beam diameter adjusting unit, a holding unit that holds the light guide, and the illumination light whose light beam diameter is adjusted by the light beam diameter adjusting unit are collected, and the condensed illumination light is incident on the light guide held in the holding unit. And a condensing lens incident on the end.

  The light beam after the light beam diameter adjustment emitted from the light beam diameter adjusting unit is, for example, parallel light.

  The beam diameter adjusting unit converts the illumination light emitted from the lamp into parallel light, and makes the converted parallel light incident on the condenser lens, and a slide unit that holds the collimate lens slidably in the optical axis direction It is good also as a structure which has. In this configuration, the diameter of the parallel light emitted from the collimating lens changes as the slide portion slides the collimating lens in the optical axis direction.

  According to the embodiment of the present invention, an endoscope light source device corresponding to a general-purpose scope that can change an illumination range (light distribution) is provided.

1 is an external view of an electronic endoscope system according to an embodiment of the present invention. 1 is a block diagram of an electronic endoscope system according to an embodiment of the present invention. It is a figure which shows the structure of the light source unit with which the electronic endoscope system of embodiment of this invention is equipped. It is sectional drawing of the slide mechanism with which the light source unit of embodiment of this invention is equipped. It is a figure which shows the state of a light source unit when a movable lens is slid to two mutually different positions in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, an electronic endoscope system will be described as an example of an embodiment of the present invention.

[Overall configuration of electronic endoscope system 1]
FIG. 1 is an external view of an electronic endoscope system 1 according to the present embodiment. As shown in FIG. 1, the electronic endoscope system 1 of this embodiment includes an electronic scope 10 and a processor 20.

  As shown in FIG. 1, the electronic scope 10 includes an insertion portion flexible tube 11 covered with a flexible sheath. The distal end portion (bent portion 13) of the insertion portion flexible tube 11 bends in response to a remote operation from the hand operation portion 14 connected to the proximal end of the insertion portion flexible tube 11. The bending mechanism is a well-known mechanism incorporated in a general endoscope, and bends the bending portion 13 by pulling the operation wire in conjunction with the rotation operation of the bending operation knob of the hand operation portion 14. The proximal end of the distal end portion 12 covered with a hard resin housing is connected to the distal end of the bending portion 13. When the direction of the distal end portion 12 changes according to the bending operation by the rotation operation of the bending operation knob, the imaging region by the electronic scope 10 moves. A universal cable 15 extends from the hand operation unit 14 and a connector unit 16 is connected to the base end thereof.

  The connector portion 16 includes a connector case 16a formed of a hard synthetic resin. The connector case 16a is composed of a front side case and a back side case having a substantially symmetrical shape. The connector case 16a accommodates and holds various parts such as an electronic circuit board in a closed space defined by fitting the front side case and the back side case. Protects from impact. The connector case 16a holds an electrical connection plug 16b and an optical connection plug 16c.

  A connector portion is provided on the front panel surface of the housing 20 a of the processor 20. The connector section includes an electrical connection jack 20b and an optical connection jack 20c. The electrical connection jack 20b is electrically connected to an image processing device built in the processor 20, and the optical connection jack 20c is optically connected to a light source device built in the processor 20. .

  The electrical connection jack 20b has a connection structure corresponding to the electrical connection plug 16b, and the optical connection jack 20c has a connection structure corresponding to the optical connection plug 16c. By connecting the electrical connection plug 16b and the optical connection plug 16c to the electrical connection jack 20b and the optical connection jack 20c, respectively, the electronic scope 10 and the processor 20 are electrically and optically connected.

  FIG. 2 is a block diagram showing a configuration of the electronic endoscope system 1 of the present embodiment. As shown in FIG. 2, a monitor 30 is connected to the electronic endoscope system 1.

  As shown in FIG. 2, the processor 20 includes a system controller 202, a timing controller 204, a memory 206, an operation panel 208, an image processing circuit 210, and a light source unit 220.

  The system controller 202 performs overall control of the entire electronic endoscope system 1 by executing various programs stored in the memory 206. Further, the system controller 202 changes various settings of the electronic endoscope system 1 in accordance with instructions from the user (surgeon or assistant) input to the operation panel 208. The timing controller 204 outputs a clock pulse for adjusting the operation timing of each unit to each circuit in the electronic endoscope system 1.

  The optical connection jack 20c holds a light guide (LCB: Light Carrying Bundle) 102 that is an optical fiber bundle provided in the optical connection plug 16c. Illumination light emitted from the light source unit 220 is incident on the incident end of the LCB 102 held by the optical connection jack 20c.

  Illumination light that has entered the LCB 102 from the incident end propagates through the LCB 102, is emitted from the exit end of the LCB 102 disposed in the distal end portion of the electronic scope 10, and is irradiated onto the subject via the light distribution lens 104. Thus, the electronic scope 10 of the present embodiment is not a special scope having a plurality of illumination optical systems divided for each use (light distribution) such as a wide area illumination optical system and a central area illumination optical system, The scope has a general configuration having a common illumination optical system that is not divided for each application.

The reflected light from the subject forms an optical image on the light receiving surface of the solid-state image sensor 108 via the objective lens 106. The solid-state image sensor 108 is an IR (Infra
Red) A single-plate color CCD (Charge-Coupled Device) image sensor in which various filters such as a cut filter 108a and a Bayer array color filter 108b are arranged on the light receiving surface, and R (in accordance with an optical image formed on the light receiving surface) Red, G (Green), and B (Blue) primary color signals are generated.

  A driver signal processing circuit 112 is provided in the connector section 16 of the electronic scope 10. The driver signal processing circuit 112 performs predetermined signal processing such as color interpolation, matrix calculation, and Y / C separation on the primary color signal input from the solid-state image sensor 108 to generate an image signal (luminance signal Y, color difference signal Cb, Cr) is generated, and the generated image signal is output to the image processing circuit 210 of the processor 20. In addition, the driver signal processing circuit 112 accesses the memory 114 and reads the unique information of the electronic scope 10. The unique information of the electronic scope 10 recorded in the memory 114 includes, for example, the number of pixels and sensitivity of the solid-state imaging device 108, an operable frame rate, a model number, and the like. The driver signal processing circuit 112 outputs the unique information read from the memory 114 to the system controller 202.

  The system controller 202 performs various calculations based on the unique information of the electronic scope 10 and generates a control signal. The system controller 202 uses the generated control signal to control the operation and timing of each circuit in the processor 20 so that processing suitable for the electronic scope 10 connected to the processor 20 is performed.

  The timing controller 204 supplies clock pulses to the driver signal processing circuit 112 and the image processing circuit 210 in accordance with timing control by the system controller 202. The driver signal processing circuit 112 controls driving of the solid-state imaging device 108 at a timing synchronized with the frame rate of the video processed on the processor 20 side in accordance with the clock pulse supplied from the timing controller 204.

  The image processing circuit 210 generates a video signal for monitor-displaying an endoscopic image or the like based on the image signal input from the driver signal processing circuit 112 under the control of the system controller 202, and the generated video signal Is output to the monitor 30. Thereby, the surgeon can perform diagnosis in the digestive tract or the like through the endoscopic image displayed on the display screen of the monitor 30.

[Configuration of Light Source Unit 220]
Next, the configuration of the light source unit 220 will be described in detail. FIG. 3 is a diagram illustrating a configuration of the light source unit 220. As shown in FIG. 3, the light source unit 220 includes a lamp 222, a front group lens 224, a movable lens (collimator lens) 226, and a rear group lens (condensing lens) 228 as an optical configuration.

  The lamp 222 emits white illumination light after being started by a lamp power igniter (not shown). As the lamp 222, a high-intensity lamp such as a xenon lamp, a halogen lamp, a mercury lamp, or a metal halide lamp is suitable. The illumination light emitted from the lamp 222 is once condensed by the front group lens 224, diverged from the condensing point, and enters the movable lens 226. The illumination light incident on the movable lens 226 is converted into parallel light by the movable lens 226. The illumination light converted into parallel light is incident on the rear group lens 228. The illumination light (parallel light) incident on the rear group lens 228 is condensed by the rear group lens 228 and incident on the incident end of the LCB 102 located near the condensing point.

  The light source unit 220 includes a slide mechanism 230 that slides the movable lens 226 in the optical axis AX direction. FIG. 4 shows a cross-sectional view of the slide mechanism 230. As shown in FIG. 4, the slide mechanism 230 includes a base 232, a ball screw 234, a holding frame 236, and a motor 238.

  The base 232 supports the ball screw 234 by a bearing 232a so as to be rotatable around an axis (optical axis AX). A part of the holding frame 236 (nut 236a) is connected to the middle of the ball screw 234. A motor 238 is connected to one end of the ball screw 234. The ball screw 234 rotates around the axis as the motor 238 is driven. As the ball screw 234 rotates around the axis, the nut 236a connected to the ball screw 234 advances and retreats in the optical axis AX direction. As the nut 236a advances and retreats in the optical axis AX direction, the movable lens 226 held by the holding frame 232 slides in the optical axis AX direction. The slide mechanism 230 slides the movable lens 226 in the direction of the optical axis AX by a distance corresponding to the amount of operation of the operation panel 208 by the user.

  5A and 5B show a state of the light source unit 220 when the movable lens 226 is slid to different positions. In the example of FIG. 5A, the movable lens 226 is close to the rear group lens 228. Hereinafter, the position of the movable lens 226 in FIG. 5A is referred to as a “first position”. In the example of FIG. 5B, the movable lens 226 is separated from the first position with respect to the rear group lens 228. Hereinafter, the position of the movable lens 226 in FIG. 5B is referred to as a “second position”.

  As shown in FIG. 5A, in a state where the movable lens 226 is slid to the first position, the illumination light is emitted from the lamp 222 and once condensed by the front group lens 224, and then from the condensing point. The light is diverged and enters almost the entire effective diameter of the movable lens 226. The movable lens 226 converts the incident divergent light into parallel light having a light beam diameter approximately the same as the effective diameter of the movable lens 226, and causes the converted parallel light to enter the rear group lens 228. On the other hand, as shown in FIG. 5B, in a state where the movable lens 226 is slid to the second position, the illumination light is emitted from the lamp 222 and once condensed by the front lens group 224. The light is diverged from the point and is incident on a region about half the effective diameter of the movable lens 226. The movable lens 226 converts the incident divergent light into parallel light having a light beam diameter that is about half the effective diameter of the movable lens 226, and causes the converted parallel light to enter the rear group lens 228.

  As can be seen from a comparison between FIG. 5A and FIG. 5B, the beam diameter of illumination light (parallel light) emitted from the movable lens 226 becomes smaller as the position of the movable lens 226 becomes farther from the rear lens group 228. Become.

The angle at which the illumination light emitted from the rear group lens 228 is collected depends on the beam diameter of the illumination light (parallel light) incident on the rear group lens 228. Specifically, the angle increases as the luminous flux diameter of the illumination light increases. In the example of FIG. 5, collection angle alpha ₁ is to be greater than the collection angle alpha ₂ which is shown in FIG. 5 (b) shown in Figure 5 (a).

In the example of FIG. 5 (a), the illumination light is incident at an incident angle alpha ₁ to LCB102, advances while being repeatedly reflected at the same reflection angle in the LCB102, are emitted at the same angle alpha ₁ to the incident angle alpha _1. On the other hand, in the example of FIG. 5B, the illumination light is incident on the LCB 102 at the incident angle α ₂ , proceeds while being repeatedly reflected at the same reflection angle in the LCB 102, and is emitted at the same angle α ₂ as the incident angle α _2. The The exit angle α ₁ is larger than the exit angle α ₂ . Therefore, in the example of FIG. 5A, a wide range of subjects is illuminated, and in the example of FIG. 5B, a narrow range of subjects is illuminated.

  Consider the case of observing a luminal organ such as the large intestine. While observing a luminal organ, when the distal end portion 12 faces the luminal path, the luminal path appears in the central region of the observation visual field, and the tube wall appears in the peripheral region of the observation visual field.

  For example, when the illumination range (light distribution) is wide and the distance between the light distribution lens 104 and the tube wall is short, halation occurs in the peripheral region of the observation field by illuminating the tube wall with illumination light with high illuminance. There is. When strong halation occurs, the amount of illumination light is excessively reduced by the automatic dimming function, leading to underexposure and it may be difficult to observe the lumen path.

  In order to solve the above problem, it is conceivable to reduce the illumination angle (light distribution) by reducing the emission angle of the illumination light by sliding the movable lens 226 away from the rear lens group 228. Thereby, it is possible to prevent halation by reducing the illuminance on the tube wall in the peripheral region of the observation visual field without causing insufficient exposure to the lumen path in the central region of the observation visual field.

  In addition, for example, when the illumination range (light distribution) is narrow and the distance between the light distribution lens 104 and the tube wall is long, exposure may be insufficient in the peripheral region of the observation field. In this case, it can be considered that the movable lens 226 is slid in the direction approaching the rear lens group 228 to increase the emission angle of illumination light and widen the illumination range (light distribution). Thereby, the illuminance with respect to the tube wall in the peripheral region of the observation visual field can be secured, and the insufficient exposure can be solved.

  As described above, according to the present embodiment, it is possible to make the subject suitable for observation by adjusting the illumination range (light distribution) according to the state of the subject being photographed.

  The above is the description of the exemplary embodiments of the present invention. Embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical idea of the present invention. For example, the embodiment of the present application also includes an embodiment that is exemplarily specified in the specification or a combination of obvious embodiments and the like as appropriate.

DESCRIPTION OF SYMBOLS 1 Electronic endoscope system 10 Electronic scope 20 Processor 220 Light source unit 222 Lamp 224 Front group lens 226 Movable lens 228 Rear group lens 230 Slide mechanism

Claims (3)

In an endoscope light source device connected to an endoscope light guide,
A lamp that emits illumination light;
A light beam diameter adjusting unit that adjusts a light beam diameter of illumination light emitted from the lamp;
A holding unit for holding the light guide;
A condensing lens that condenses the illumination light whose light beam diameter is adjusted by the light beam diameter adjusting unit, and makes the collected illumination light enter an incident end of a light guide held by the holding unit;
Comprising
Endoscope light source device. The light beam after the light beam diameter adjustment emitted from the light beam diameter adjustment unit is parallel light,
The endoscope light source device according to claim 1. The luminous flux diameter adjusting unit is
A collimating lens that converts the illumination light emitted from the lamp into parallel light, and enters the converted parallel light into the condenser lens;
A slide part for holding the collimating lens slidably in the optical axis direction;
Have
When the slide portion slides the collimating lens in the optical axis direction, the beam diameter of parallel light emitted from the collimating lens changes.
The endoscope light source device according to claim 2.

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