JP4864494B2 - Endoscope device with infrared cut filter - Google Patents

Description

  The present invention relates to an endoscope apparatus that observes an affected area using a light source such as a lamp, and more particularly to an infrared cut filter provided around a light source.

  In the endoscope apparatus, in order to illuminate an observation site in a body cavity, light emitted from the lamp is guided to the distal end of the scope by a light guide provided in the scope and emitted from the distal end of the scope. In order to improve the color reproducibility of the observed image by eliminating long-wavelength light (infrared rays) other than visible light contained in the lamp light, or the observation site is affected by heat due to the infrared component having a heating action. In order to prevent this, an infrared cut filter is provided between the lamp and the light guide.

If the infrared cut filter is damaged by direct illumination light, an infrared component may be applied to the observation site, which may adversely affect the scope tip or observation site. For example, an ultraviolet cut filter is placed between the infrared cut filter and the light source. Thus, damage to the infrared cut filter is prevented (see Patent Document 1).
Japanese Patent Laid-Open No. 5-232387

  The infrared cut filter may be damaged by causes other than heat, such as external impacts. If the operator does not notice the damage to the infrared cut filter and continues endoscopic work such as surgery, the tip of the scope including the image sensor The effect of heat occurs on the part and the observation site.

  An endoscope apparatus according to the present invention is an endoscope apparatus that is safe for a subject against damage to an infrared cut filter and prevents a failure of the apparatus. A light source that emits illumination light and a light source are driven. A light source driving unit, an infrared cut filter arranged in the optical path of the illumination light and blocking light in the long wavelength region, a light shielding plate, an aperture for adjusting the amount of illumination light, and the brightness of the subject image are appropriate In order to maintain the brightness, an aperture driving unit is provided that drives the aperture to place the light shielding plate in the optical path and changes the position of the light shielding plate.

  As a configuration of the diaphragm, for example, a diaphragm that provides a light-shielding plate at the end and rotates a support portion that supports the light-shielding plate may be used, and the optical path of the light that travels toward the distal end of the scope is partially The diaphragm rotates so as to shield it. In this case, the diaphragm driving unit rotates the diaphragm. As the configuration of the diaphragm driving unit, an actuator for driving a diaphragm such as a motor and an actuator driving unit for driving the actuator are provided. The infrared cut filter may be disposed between the diaphragm and the light source.

  In the endoscope apparatus of the present invention, the infrared cut filter is provided with a conductor pattern, and light from the light source passes through the infrared cut filter having the conductor pattern. The conductor pattern is configured as a part of a driving signal circuit of the light source driving unit or the diaphragm driving unit. For example, a conductive pattern may be formed on the infrared cut filter by depositing a conductive film. When the infrared cut filter is damaged due to external impact or the like, the conductor pattern is damaged accordingly, and the drive signal circuit is disconnected. Therefore, a driving signal is not output from the aperture driving unit to the aperture (here, referred to as an aperture non-driving state).

  In the endoscope apparatus of the present invention, the diaphragm is supported by the driving force from the diaphragm driving unit, and in addition to supporting the diaphragm, the driving force is supplied to the diaphragm so as to change the position of the light shielding plate. The endoscope apparatus includes a positioning member that positions the light shielding plate at a light shielding position that blocks light from the light source when the diaphragm is brought into a non-driven state due to the disconnection of the conductor pattern. Since the light-shielding plate is placed at the light-shielding position, illumination light containing light in the long wavelength region is not transmitted to the scope tip and the observation site, and no thermal problem occurs. In addition, since the illumination light is not irradiated to the observation site, the operator can immediately recognize the breakage of the infrared cut filter during the endoscopic work.

  When the conductor pattern is configured as a part of the circuit of the aperture driving unit, for example, the conductor pattern may be connected to the driving signal circuit in the actuator driving unit. On the other hand, when the conductor pattern is configured as a part of the light source driving unit, the conductor pattern may be connected to the driving signal circuit in the light source driving unit.

  As a configuration of the positioning means, for example, the diaphragm driving unit is driven while supporting the diaphragm so as to oppose the dead weight of the diaphragm, and is stopped at the light-shielding position when the diaphragm is naturally moved by the dead weight of the diaphragm in the non-driven state. It is sufficient to provide a support plate that is positioned by contacting the diaphragm at the light shielding position. Alternatively, the diaphragm is urged in a certain direction by an urging member such as a spring, and the diaphragm drive unit is driven while supporting the diaphragm so as to oppose the force of the urging member. It may be configured to start moving at the light shielding position.

  The endoscope dimming device of the present invention has an infrared cut filter disposed in the optical path of illumination light from a light source, a light blocking plate, a diaphragm for adjusting the amount of illumination light, and a non-driven state of the diaphragm. A positioning member that positions the light shielding plate at a light shielding position for blocking illumination light, and the infrared cut filter is a part of a signal circuit for driving the light source driving unit or the diaphragm driving unit, and is in the optical path of the illumination light. It has the conductor pattern located, It is characterized by the above-mentioned.

  ADVANTAGE OF THE INVENTION According to this invention, when an infrared cut filter is damaged, it can respond safely, without having a bad influence on a test subject and an endoscope apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram of an electronic endoscope apparatus according to the first embodiment.

  The electronic endoscope apparatus includes a video scope 10 and a processor 20, and the video scope 10 is detachably connected to the processor 20. The processor 20 is connected with a monitor 60 and a keyboard (not shown).

  The processor 20 is provided with a lamp 22 that emits white light, such as a halogen lamp or a xenon lamp, and a lamp power source 23 drives the lamp 22 to light. The illumination light emitted from the lamp 22 is incident on the incident end 12 </ b> A of the light guide 12 via the infrared cut filter 25 and the condenser lens 27. The light guide 12 that is an optical fiber bundle guides light from the lamp 22 to the distal end portion of the video scope 10, and the light emitted from the light guide 12 exits from the distal end portion of the scope via the light distribution lens 14. Thereby, illumination light is irradiated to the subject.

  The light reflected by the subject irradiated with the illumination light reaches the light receiving surface of the CCD 17 through the objective lens 15, and a subject image is formed on the light receiving surface of the CCD 17. A complementary color mosaic filter (not shown) is disposed in front of the CCD 17 corresponding to each pixel, and an analog image signal corresponding to the subject image is photoelectrically converted based on the light passing through the filter of each color element. appear. The image signals are sequentially read out one field at a time interval (here, 1/60 seconds) in accordance with a TV standard such as the NTSC system and sent to the video signal processing circuit 30 of the processor 20. The CCD 17 is driven by an image sensor driving circuit 31 of the processor 20.

  The video signal processing circuit 30 amplifies and digitizes the analog image signal and performs various signal processing such as white balance adjustment and gamma correction to generate a video signal such as an NTSC signal. Is done. The video signal is sent to the monitor 60, whereby the color observation image is displayed on the monitor 60 as a moving image. The video signal output from the video signal processing circuit 30 is sequentially sent to the dimming circuit 28.

  The system control circuit 33 including the timing controller 32 controls the operation of the processor 20 and outputs a control signal to the lamp power source 23. The timing controller 32 outputs a clock pulse signal for adjusting the timing of signal processing to the image sensor driving circuit 31 and the like. The light control circuit 28 is configured by a DSP (Digital Signal Processor) and outputs a control signal to the motor 24. The dimming circuit 28 sequentially detects luminance values indicating the brightness of the subject image based on video signals sent at 1/60 second intervals. Then, a difference between the actual luminance value of the subject image and the reference luminance value is detected, and a control signal is output to the motor 24 in accordance with the luminance level difference. The reference luminance value indicates the appropriate brightness of the subject image, and is set in advance by the operator through a keyboard operation or the like.

  The diaphragm 26 provided between the infrared cut filter 25 and the condensing lens can be rotated about the axis of the motor 24 so that the brightness of the subject image is maintained at an appropriate brightness. Then, the diaphragm 26 is rotated based on the control signal. The positioning plate 29 is fixed below the diaphragm 26 and positions the diaphragm 26 at the light shielding position.

  FIG. 2 is a diagram showing the infrared cut filter 25. FIG. 3 is a diagram showing the spectral transmission characteristics of the infrared cut filter.

  A conductive film 25CP serving as a conductor pattern is formed on the surface 25S of the infrared cut filter 25 by vapor deposition, and connection portions 25PT are provided at both ends. Both ends of the connection portion 25PT are connected to the dimming circuit 28, and the conductive film 25CP is configured as a part of the driving signal circuit of the dimming circuit 28. That is, a driving signal for driving the motor 24 is output to the motor 24 via the conductive film 25CP. The infrared cut filter 25 is disposed in the optical path of the illumination light of the lamp 22, and the light emitted from the lamp 22 passes through the surface 25S on which the conductive film 25CP is formed and enters the light guide 12. As shown in FIG. 3, the infrared cut filter 25 here blocks light having a wavelength of 700 nm or more, that is, infrared rays (including light in the near infrared region).

  FIG. 4 is a control block diagram of automatic light control processing.

  When a luminance difference signal, which is a difference between a preset reference luminance value and a luminance value detected by the luminance detector 28S, is sent to the driving unit 28T, a driving signal corresponding to the luminance level difference is output. The drive signal is output to the motor 24 via the conductive film 25CP of the infrared cut filter 25 between the drive unit 28T and the motor 24. The motor 24 rotates a predetermined amount to rotate the diaphragm 26.

  FIG. 5 shows the arrangement of the diaphragm 26.

  The diaphragm 26 has a light shielding plate 26 </ b> B at an end thereof, and is attached around the axis C of the motor 24. The diaphragm 26 is rotated by the rotation of the motor 24 and is movable in a range from the retracted position of the light beam LB of the light from the lamp 22 to the light shielding position where the light beam LB is completely blocked. The diaphragm 26 blocks the light beam LB, that is, a part of the optical path so that the brightness of the subject image displayed on the monitor 60 is maintained at an appropriate brightness.

  The rotation axis C of the diaphragm 26 is not located along the vertical direction from the light beam LB, and the diaphragm 26 is supported by the driving force of the motor 24. That is, an attempt to rotate the shaft by the dead weight of the diaphragm 26 is suppressed, and the light shielding plate 26B is moved to a predetermined position for light quantity adjustment while supporting the diaphragm 26.

  When the infrared cut filter 25 is damaged by applying an external force or the like to the electronic endoscope apparatus, the conductive film 25CP is disconnected and a drive signal is not output to the motor 24. As a result, the diaphragm 26 is not supported by the driving force and starts to move like a pendulum by its own weight. The positioning plate 29 is a member that positions the light shielding plate 26B at a light shielding position, that is, a position that blocks substantially the entire light beam LB, and the diaphragm 26 stops when the light shielding plate 26B hits the positioning plate 29. When the infrared cut filter 25 is damaged and the diaphragm 26 is stopped by the positioning plate 29, the illumination light hardly reaches the subject because of the light shielding plate 26B.

  As described above, according to the first embodiment, the infrared cut filter 25 is disposed between the diaphragm 26 and the lamp 22, and the conductive film 25 </ b> CP is formed on the surface 25 </ b> S of the infrared cut filter 25. The conductive film 25CP is configured as a part of the driving signal circuit of the dimming circuit 28. A positioning plate 29 for positioning the diaphragm 26 is fixed at a light shielding position where the light beam LB is completely shielded by the light shielding plate 26B.

  Thereby, after the infrared cut filter 25 is damaged, light in a long wavelength region such as infrared rays is not irradiated to the observation site, and the influence of heat does not occur. In addition, since the amount of illumination light suddenly significantly decreases, the operator can immediately detect the breakage of the infrared cut filter. Further, since the diaphragm 26 which is a light amount adjusting member is also used to prevent irradiation of illumination light including infrared rays, the configuration is simplified.

  Next, the electronic endoscope apparatus according to the second embodiment will be described with reference to FIG. In the second embodiment, the diaphragm is biased. About another structure, it is the same as 1st Embodiment.

  FIG. 6 is a diagram showing the arrangement of stops in the second embodiment.

  The diaphragm 26 is biased by a spring 37 in a direction in which the light beam LB is present, that is, a direction in which the amount of illumination light is reduced. The motor 24 supports the diaphragm 24 so as to oppose the force of the spring 37, and the diaphragm 26 rotates on the axis between the retracted position and the light shielding position. The positioning plate 29 is attached at a position where the light shielding plate 26B is stopped at the light shielding position.

  When the infrared cut filter 25 is damaged, the drive signal is not transmitted to the motor 24 due to the damage of the conductive film 25CP, and as a result, the diaphragm 26 is axially rotated to the light beam LB side by the elastic force of the spring 37. Then, the light shielding plate 26B hits the positioning plate 29, and the diaphragm 26 stops. Thereby, the illumination light does not reach the observation site. The elastic force of the spring 37 may be set so that the light shielding plate 26B is positioned at the light shielding position.

  Next, an electronic endoscope apparatus according to a third embodiment will be described with reference to FIGS. In the third embodiment, the conductive film 25CP of the infrared filter is configured as a part of the circuit of the lamp power supply 23 ′, and when the infrared cut filter 25 is damaged, the conductive film 25CP is disconnected and the lamp is turned off. The power source 23 'operates. About another structure, it is the same as 1st Embodiment.

  FIG. 7 is a partial block diagram of an electronic endoscope apparatus according to the third embodiment. FIG. 8 is a control block diagram according to the third embodiment.

  The conductive film 25CP of the infrared cut filter 25 is interposed between the lamp power source 23 ′ and the lamp 22, and is configured as a part of the driving signal circuit supplied to the lamp 22, and the driving signal is supplied to the conductive film 25CP. Is output to the lamp 22 via. When the infrared cut filter 25 is damaged, the driving signal is not transmitted from the lamp power source to the lamp 22 by cutting the conductive film CP, and as a result, the lamp 22 is turned off.

  The configuration of actuators such as an aperture and a motor may be other than the first and second embodiments. Moreover, you may provide a conductor pattern in an infrared cut filter other than vapor deposition of a electrically conductive film. Moreover, you may apply to the light source device for fiberscopes.

It is a block diagram of the electronic endoscope apparatus which is 1st Embodiment. It is the figure which showed the infrared cut filter. It is the figure which showed the spectral transmission characteristic of the infrared cut filter. It is a control block diagram of automatic light control processing. It is the figure which showed arrangement | positioning of an aperture_diaphragm | restriction. It is the figure which showed arrangement | positioning of the aperture_diaphragm | restriction in 2nd Embodiment. It is a partial block diagram of the electronic endoscope apparatus in 3rd Embodiment. It is a control block diagram in a 3rd embodiment.

Explanation of symbols

10 Videoscope 20 Processor 22 Lamp (light source)
23 Lamp power supply 24 Motor 25 Infrared cut filter 25CP Conductive film (conductor pattern)
26 Diaphragm 26B Light shielding plate 28 Light control circuit 29 Positioning plate (positioning member)

Claims (9)

A light source that emits illumination light;
A light source driving unit for driving the light source;
An infrared cut filter disposed in the optical path of the illumination light;
A diaphragm having a light shielding plate and adjusting the amount of illumination light;
An aperture drive unit that drives the aperture and arranges the light shielding plate in the optical path of the illumination light so as to maintain the brightness of the subject image at an appropriate brightness;
A positioning member that positions the light shielding plate at a light shielding position that blocks illumination light in a non-driving state of the diaphragm, in which a driving signal is not output from the diaphragm driving unit to the diaphragm;
The diaphragm is supported by a driving force from the diaphragm driving unit,
The infrared cut filter is a part of the driving signal circuit of the diaphragm driving unit, and has a conductor pattern located in the optical path of the illumination light,
The endoscope apparatus according to claim 1, wherein the diaphragm is brought into a non-driven state when the conductor pattern is damaged along with the damage of the infrared cut filter. The aperture drive unit is
An actuator for driving the diaphragm;
An actuator driving unit for driving the actuator,
The endoscope apparatus according to claim 1, wherein the conductor pattern is connected to a driving signal circuit in the actuator driving unit.   The endoscope apparatus according to claim 1, wherein the infrared cut filter blocks light having a wavelength of 700 nm or more. The infrared cut filter has a conductive film;
The endoscope apparatus according to claim 1, characterized in that the conductive material pattern is formed as the conductive film.   The endoscope apparatus according to claim 1, wherein the diaphragm is provided with the light shielding plate at an end thereof and is rotatable about an axis. The positioning member has a support plate that positions the diaphragm by contacting the diaphragm at the light shielding position;
The endoscope apparatus according to claim 1, wherein the diaphragm is positioned at the light shielding position by its own weight when the diaphragm is not driven. The positioning member has a biasing member that biases the diaphragm to the light shielding position,
The endoscope apparatus according to claim 1, wherein the diaphragm is positioned at the light shielding position by the biasing member when the diaphragm is not driven.   The endoscope apparatus according to claim 1, wherein the infrared cut filter is disposed between the diaphragm and the light source. An infrared cut filter disposed in the optical path of the illumination light from the light source;
A diaphragm having a light shielding plate and adjusting the amount of illumination light;
An aperture drive unit that drives the aperture and arranges the light shielding plate in the optical path of the illumination light so as to maintain the brightness of the subject image at an appropriate brightness;
A positioning member that positions the light shielding plate at a light shielding position that blocks illumination light in a non-driving state of the diaphragm, in which a driving signal is not output from the diaphragm driving unit to the diaphragm;
The diaphragm is supported by a driving force from the diaphragm driving unit,
The infrared cut filter is a part of the driving signal circuit of the diaphragm driving unit, and has a conductor pattern located in the optical path of the illumination light,
The dimmer for an endoscope, wherein the diaphragm is brought into a non-driven state when the conductor pattern is damaged along with the damage of the infrared cut filter.

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