JP5797031B2 - Optical scanning endoscope device - Google Patents

Description

  The present invention relates to an endoscope apparatus that images a subject such as an inner wall of an organ with a scope and displays an observation image on a monitor, and more particularly, to a structure at a distal end portion of the endoscope apparatus by optical scanning.

  In an endoscope apparatus (also referred to as SFE) provided with a scanning optical fiber, the distal end portion of the optical fiber provided in the scope is held by a piezoelectric actuator. The actuator can two-dimensionally vibrate and resonate the fiber tip. Specifically, the fiber tip is helically driven while modulating and amplifying the vibration amplitude. As a result, the illumination light is scanned spirally with respect to the observation site.

  A plurality of photosensors are provided around the optical fiber at the distal end of the scope, and the light reflected from the observation site is sequentially detected by the photosensor in time series, and an image signal is generated. By repeating the spiral motion of the fiber tip periodically (for example, at intervals of 1/30 seconds), an image signal for one frame is sequentially detected, and a circle-shaped image is displayed on the monitor (for example, Patent Documents 1 and 2).

  On the other hand, instead of driving the tip of the optical fiber to scan the illumination light, it is also possible to provide an LED at the tip of the scope and deflect and scan the light from the light source (see Patent Document 3).

JP 2008-165236 A JP 2008-43763 A JP 2009-240621 A

  When the optical scanning is started with the start of the endoscopic work, the temperature of the actuator constituted by the piezoelectric element or the like suddenly rises after a while due to the heat generated by the actuator from the initial low temperature state. Due to this unstable temperature change, an unstable time occurs after the spiral scanning starts, and misalignment occurs at the irradiation position. In particular, when an LED is attached to the tip of the probe-like support and the light is scanned, it is difficult to scan accurately because a weight is applied to the tip.

  Therefore, it is required to accurately scan the illumination light without being affected by the temperature change.

  An endoscope apparatus according to the present invention is an endoscope apparatus that scans illumination light by providing an LED at a distal end portion of a scope, and extends along an LED provided at the distal end portion of the scope and an axis of the distal end portion of the scope. , A holding member that holds the LED at one end thereof (scope tip side), and a driving unit that drives the holding member to scan illumination light emitted from the LED.

  The holding member may be a material whose tip can draw a scanning orbit by a force from the driving unit, such as a linear or elongated elastic member. For example, a piezoelectric actuator or the like can be applied to the driving unit, and the holding member can be scanned so as to perform spiral scanning. The photosensor can be provided, for example, around the drive unit.

  Furthermore, the endoscope apparatus of the present invention includes a photosensor that receives reflected light from a subject and an image processing unit that generates an image signal based on a pixel signal from the photosensor. The wiring connected to the LED is wound around at least a part of the driving unit.

  In the present invention, the wiring connected to the LED, such as the drive current supply, is wound around a part of the outer surface of the drive unit, etc., so heat is generated from the wiring with the start of optical scanning, and the heat is in a wound state. It is transmitted directly from the wiring to the drive unit, and the temperature of the drive unit and its surroundings immediately rises. Therefore, there is no sudden temperature increase after the start of scanning, and stable optical scanning is performed.

  The number of windings of the wiring, the winding method, the pitch interval, and the like can be determined by the arrangement of the drive unit, the structure of the scope tip, the length of the wiring, and the like. It is possible to wind the entire drive unit, or it is possible to wind only a part that is easily affected by temperature changes.

  In order to prevent the wiring from being disturbed during scanning, it is desirable to wind the wiring around a holding member. For example, it is possible to wind the wiring around at least the drive unit side end of the holding member and to further transfer the heat to the drive unit.

  Since a rapid temperature change affects the operation of the photosensor, it is desirable that the temperature change be stable even in the vicinity of the photosensor. In the case where a photosensor is provided around the drive unit, it is preferable that the wiring is wound around the drive unit along the scope distal end axis to a position near the photosensor.

  In order to further generate heat, it is possible to provide a resistor for transferring heat to the drive unit in the drive substrate of the photosensor.

  The scanning endoscope according to the present invention includes an LED provided at a distal end portion, a holding member extending along an axis of the distal end portion, and holding the LED at the end portion, and an end portion of the holding member. A drive unit that scans illumination light emitted from the LED by driving, and a wiring connected to the LED is wound around at least a part of the drive unit.

  As described above, according to the present invention, in the scanning endoscope apparatus in which the LED is provided at the distal end portion of the scope, the illumination light can be continuously and accurately scanned without being affected by heat.

It is a block diagram of the endoscope apparatus which is this embodiment. It is a typical internal block diagram of a scope front-end | tip part.

  Hereinafter, the electronic endoscope apparatus according to the present embodiment will be described with reference to the drawings.

  FIG. 1 is a block diagram of an endoscope apparatus according to this embodiment.

  The endoscope apparatus includes a video scope (hereinafter referred to as a scope) 10 including a plurality of photosensors 14 and a processor 40 to which the scope 10 is detachably attached, and a monitor 50 is connected to the processor 40. . A scanning unit 13 to which an LED (Light Emitting Diode) 12 is attached is provided at the scope distal end portion 10B.

  The LED illumination circuit 42 provided in the processor 40 is a circuit that supplies a drive current to the LED 12 of the scope distal end portion 10B, and a current is supplied to the LED 12 through the signal lines CB0 and CB3. The scanning unit 13 scans the light emitted from the LED 12 in a spiral shape toward the observation site.

  The light reflected at the observation site enters the scope tip 10B and enters a plurality of photosensors 14 provided at the scope tip 10B. In the plurality of photosensors 14 in which R, G, and B color elements are arranged on the light receiving surface, pixel signals generated by photoelectric conversion are sequentially read out, and image signal processing in the processor 40 is performed via the signal cable CB1. It is sent to the circuit 44.

  In the image signal processing circuit 44, signal processing such as amplification processing, color adjustment, and pixel position correction processing is performed on the image signal to generate a video signal. By outputting the video signal to the monitor 50, a color observation image is displayed on the monitor 50.

  The controller 46 controls the entire operation of the processor 40 and outputs a control signal to the scanning unit 13 via the signal cable CB2. The timing controller (not shown) outputs a clock pulse signal that synchronizes the readout timing of the pixel signal with the scanning timing by the scanning unit 13 to the drive unit (not shown) of the photosensor 14.

  FIG. 2 is a schematic internal configuration diagram of the distal end portion of the scope.

  The scanning unit 13 provided inside the housing 16 of the cylindrical scope distal end portion 10B includes a piezoelectric actuator 15A made of a piezoelectric element such as PTZ piezoelectric ceramic, and an elongated holding member 15B having a probe shape. The cylindrical piezoelectric actuator 15A fixed by the support member 15C is coaxially disposed along the scope axis L, and the holding member 15B is coaxially attached to the piezoelectric actuator 15A.

  The elastic holding member 15B extends along the scope axis L and is held in a cantilever shape by the piezoelectric actuator 15A. The LED 12 is fixed to the distal end portion 15T of the holding member 15B with an adhesive or the like, and the emission direction of the LED 12 faces the distal end direction of the scope.

  On the distal end side (observation site side) of the scope distal end portion 10B, an optical system 17 having two lenses including an objective lens is fixedly disposed by a fixed frame 13C, and illumination light emitted from the LED 12 is transmitted to the scope distal end portion. Irradiate from 10B toward the observation site. The optical axis E of the optical system 17 coincides with the scope axis L.

  The piezoelectric actuator 15A is deformed by an inverse piezo effect and drives the holding member 15B two-dimensionally. That is, the holding member 15B is vibrated based on a biaxial coordinate system orthogonal to each other. At this time, the amplitude of the holding member 15B is modulated and amplified so that the tip 15T of the holding member 15B draws a spiral trajectory. As a result, the illumination light emitted from the LED 12 irradiates the observation site as light having a periodic spiral pattern.

  As the observation site is illuminated by the spiral motion of the holding member tip 15T, the reflected light sequentially enters the plurality of photosensors 14. Pixel signals detected by the photosensor 14 are read out from the photosensor 14 in time series and sent to the processor 40. Each photodiode has a color filter of any one of R, G, and B arranged on the light receiving surface, and is assigned so that the ratio of R, G, and B is generally equal.

  In the image signal processing circuit 44 (FIG. 1), the irradiation position in the spiral motion is associated with the pixel position of the detected pixel signal. As a result, images for one frame are sequentially generated. The color of each pixel is detected based on the color component of the detected pixel signal. For example, when the R component pixel signal is greater than the G and B component pixel signals, the pixel color is determined to be reddish.

  Here, the configuration of the substrate / wiring at the distal end will be described. The flexible substrate 21 arranged along the inner peripheral surface of the scope distal end 10B has both the drive circuit for the photosensor 14 and the drive circuit for the LED 12 provided side by side. It is a substrate and is connected to the signal cables CB0 and CB1. The signal cable CB2 is connected to a flexible substrate (not shown) for the piezoelectric actuator.

  A wiring CB3 for supplying a driving current to the LED 12 is connected to the substrate 21 and is connected to the LED 12 as a winding. As shown in FIG. 2, the wiring CB3 is wound around the entire holding member 15B so as not to move during scanning, and is also spirally wound around the piezoelectric actuator 15A to the vicinity of the photosensor 14. Yes. The number of windings and the winding pitch are set at predetermined intervals.

  When the piezoelectric actuator 15A is driven by the start of the endoscopic operation and the LED 12 is turned on, the holding member 15B spirally moves and a drive current flows through the wiring CB3. When the drive current flows, heat is generated from the wiring CB3.

  By generating heat from the wiring CB3, the ambient temperature of the piezoelectric actuator 15A quickly increases immediately after the start of driving. As a result, the internal temperature of the distal end of the scope, particularly the ambient temperature of the piezoelectric actuator 15A and the photosensor 14, immediately rises immediately after the start of work, and then becomes substantially constant and stable.

  Due to space limitations, it is difficult to install a heat source device such as a heater at the scope tip, but in this embodiment, the temperature at the scope tip is increased immediately after the start without placing such a device. It is possible to prevent unstable driving of the piezoelectric actuator due to a sudden temperature change.

  Also, the photosensor may interfere with accurate pixel signal detection due to an unstable temperature change. However, since the wiring CB3 is wound to the vicinity of the photosensor, the photosensor does not become unstable. Can maintain an appropriate temperature.

  Further, a resistor 19 for generating heat is provided in the vicinity of the photosensor on the substrate 21. This makes it easier for the temperature to rise. However, it may be configured without providing a heat generating resistor. In that case, it is possible to generate sufficient heat by increasing the winding pitch, the number of turns, and the like of the wiring.

  As described above, according to the present embodiment, in the scanning endoscope apparatus in which the LED 12 is provided at the distal end of the scope and the scanning unit 13 scans the illumination light, the piezoelectric actuator 15A spirals the elastic holding member 15B extending in the longitudinal direction. To drive. Then, the wiring CB3 connected to the LED 12 attached to the holding member tip 15T is wound around the holding member 15B and the piezoelectric actuator 15A.

  Considering only raising the ambient temperature of the piezoelectric actuator 15A, the wiring CB3 may be wound only around the actuator. Various winding methods can be applied instead, and multiple windings or winding without gaps may be used. It is possible to wind densely or sparsely in consideration of heat generation.

  The material and configuration of the holding member may be any material that can scan light spirally. Moreover, it is also possible to configure so as to scan with a pattern other than the spiral pattern.

  In the present embodiment, the LEDs are arranged in the video scope, but the present invention can also be applied to a probe type scope that can be inserted into a forceps channel provided in a video scope having an image sensor such as a conventional CCD.

10 Scope 13 Scanning Unit 14 Photosensor 15A Piezoelectric Actuator 15B Holding Member CB3 Wiring

Claims (5)

An LED provided at the distal end of the scope;
An elastic holding member extending along the axis of the scope tip and holding the LED at one end thereof;
By the holding member attached to said holding member and coaxially held cantilevered, driving the holding member, and an actuator to scan the illumination light emitted from the LED,
A photo sensor that receives reflected light from the subject;
An image processing unit that generates an image signal based on a pixel signal from the photosensor,
An endoscope apparatus, wherein a wire connected to the LED is wound around at least a part of the actuator . The photosensor is provided around the actuator ;
The endoscope apparatus according to claim 1, wherein the wiring is wound around the actuator along a scope distal end axis to a position in the vicinity of the photosensor. The endoscope apparatus according to claim 1, wherein the wiring is further wound around at least an actuator side end of the holding member. The endoscope apparatus according to any one of claims 1 to 3, wherein a resistor that conducts heat to the actuator is provided in a driving substrate of the photosensor. An LED provided at the tip,
An elastic holding member extending along the axis of the tip and holding the LED at one end thereof;
Holding the holding member attached coaxially with the holding member in cantilever, by driving the holding member, and an actuator to scan the illumination light emitted from the LED,
A scanning scope, wherein a wire connected to the LED is wound around at least a part of the actuator .

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