JP2001314367A - Wide band laser cut-off filter and endoscopic instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wide band laser cut-off filter for reducing a plurality of types of near infrared lasers and an endoscopic instrument. SOLUTION: The wide band laser cut-off filter 14 has a thickness of 1 mm or less and a transmittance of a light having a wavelength region of 800 to 1,070 nm of 0.05% or less. This filter 14 is associated with the endoscopic instrument. The endoscope comprises a CCD 15, an objective 13 for forming an image of a subject on an imaging surface of the CCD 15, and the wide band laser cut-off filter 14 inserted between the CCD 15 and the objective 13. Since the near infrared laser used to a laser treatment is reduced by the filter 14, the CCD 15 can always normally acquire a subject's image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a broadband laser cut filter and an endoscope apparatus having the filter.

[0002]

2. Description of the Related Art Conventionally, an endoscope apparatus has been used for observation and diagnosis in a living body. Recently, an endoscope device (electronic endoscope device) in which a CCD (charge-coupled device) is embedded in the distal end portion of the endoscope has been developed. This type of endoscope apparatus can capture an image of a body cavity wall or the like, which is a subject, using the CCD, and display the captured image on a monitor.

[0003] Further, the endoscope apparatus is used not only for observation and diagnosis, but also for treatment. As one of the treatment methods, a laser treatment method is known. In this laser treatment method, a surgeon irradiates a tissue to be treated with a laser beam using a laser probe protruding from the end of an endoscope, thereby incising and cutting the tissue.
It is to coagulate.

[0004] For this laser treatment, a YAG laser is often used. When an operator performs laser treatment under endoscopic observation, the YAG laser used for the treatment is reflected by living tissue and enters the CCD. Then, since the charges are excessively accumulated in each pixel of the CCD, an image of the subject cannot be obtained during the laser treatment.

Therefore, an endoscope apparatus has been developed in which a laser cut filter is inserted in an optical path from a subject to a CCD so that an image of the subject can be obtained even during laser treatment. FIG. 5 is a graph showing the spectral transmission characteristics of a conventional laser cut filter. As shown in FIG.
The laser cut filter is 1064 by YAG laser.
The light in the wavelength range around nm is reduced.

For this reason, YA injected during laser treatment
Light reflected by the G laser is reduced by a laser cut filter before reaching the CCD. Therefore, even during the laser treatment, the CCD can acquire an image of the subject.

[0007]

To date, YAG lasers have been most widely used for laser treatment, but other near-infrared lasers are also used. In particular, inexpensive semiconductor lasers have been used.
There are many types of semiconductor lasers used for medical purposes,
The wavelength range varies from about 800 nm to 950 nm.

As shown in FIG. 5, in the conventional laser cut filter, only the light from the YAG laser is reduced, but the light from the semiconductor laser cannot be reduced. For this reason, according to the endoscope apparatus incorporating the conventional laser cut filter, the subject image cannot be obtained during the laser treatment with the semiconductor laser.

In order to reduce both the YAG laser and the semiconductor laser, a plurality of filters corresponding to respective wavelength ranges are required. However, since the distal end of the endoscope is inserted into a living body, its size cannot be increased. Therefore, the designer cannot design to store a plurality of filters in the distal end portion of the endoscope.

It is an object of the present invention to provide a broadband laser cut filter which is compact and reduces a plurality of types of near-infrared lasers, and an endoscope device incorporating this filter.

[0011]

In order to solve the above problems, the present invention employs the following configuration.

That is, the broadband laser cut filter of the present invention is disposed on an optical path between an image sensor and an objective lens for forming an image of a subject on the image sensor, and has a wavelength of 800 nm.
The transmittance for light in the wavelength range of
It is characterized by being 5% or less and transmitting visible light. This broadband laser cut filter may be formed in a single plate having a thickness of 1 mm or less.

With this configuration, the broadband laser cut filter can reduce the amount of near-infrared laser used for medical purposes. Therefore, if this broadband laser cut filter is inserted between the objective lens and the image sensor, even if a near infrared laser for medical use enters from the objective lens, the near infrared laser will Since it is reduced by the filter, it does not affect the acquisition of the subject image by the imaging device.

[0014] An endoscope apparatus according to the present invention comprises an image sensor,
An objective lens for forming an image of the subject on the imaging element;
A wide-band laser cut filter disposed on an optical path of the objective lens and the image sensor. The imaging device, the broadband laser cut filter, and the objective lens may be arranged in a distal end fixed to a distal end of an insertion section to be inserted into a living body.
Further, this endoscope apparatus has a wavelength of 800 nm to 1070 n.
A laser probe that emits a laser having a wavelength in the wavelength range of m may be provided.

[0015] The imaging device may be a CCD. Then, the endoscope apparatus may generate a color image by a plane sequential method using a rotation filter. Further, the endoscope device may generate a color image by a simultaneous method using a color CCD.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically illustrating the endoscope apparatus according to the present embodiment. As shown in FIG.
The endoscope device includes an endoscope 1, an external device 2, and a laser treatment device 3.

The endoscope 1 has a flexible insertion portion and a distal end attached to the distal end of the insertion portion.
The insertion portion and the distal end are inserted into a living body. However, FIG. 1 does not show the specific shapes of the insertion portion and the distal end portion. And in this tip,
Light distribution lens 11, light guide 12, objective lens 13,
A broadband laser cut filter 14 and a CCD area sensor (hereinafter abbreviated as CCD) 15 are incorporated.

At the end, at least three through-holes are opened, one of which is used as a forceps hole, and the other two are a light distribution lens 11 and an objective lens 13. Are sealed by being fitted. Note that a forceps insertion hole is opened at the base end side of the insertion portion, and the forceps insertion hole and the forceps hole are communicated with each other by a forceps tube (not shown).

The light guide 12 is constituted by a number of multimode optical fibers bundled densely, and both end surfaces thereof are respectively formed as an incident surface through which light is incident and an exit surface through which light is emitted. The light guide 12 has an emission surface facing the light distribution lens 11 and an end on the incident surface side is drawn into the external device 2.

The CCD 15 is provided with an endoscope 1 so that an image of a subject is formed by the objective lens 13 on the imaging surface.
Is fixed within the distal end of the Note that the CCD 15 corresponds to an image sensor. A broadband laser cut filter 14 is inserted on the optical path between the objective lens 13 and the CCD 15. The configuration of the filter 14 will be described later.

Next, the external device 2 will be described. The external device 2 includes a light source 21, an infrared cut filter 22, a diaphragm 23, a rotary filter 24, a filter driving motor 25,
And a condenser lens 26, and a control unit 27.

The light source 21 emits white light and emits the white light as substantially parallel light. And this light source 2
On the optical path of the white light emitted from 1, an infrared cut filter 22, a diaphragm 23, a rotating filter 24, and a condenser lens 26 are arranged in this order. The infrared cut filter 22
By reducing infrared rays in the white light emitted from the light source 21, the subsequent radiation of heat to the optical path is prevented. The diaphragm 23 is connected to the control unit 27. The control unit 27 can control the aperture 23 to adjust the amount of light transmitted through the infrared cut filter 22.

The rotary filter 24 has a disk shape and has three color filters of RGB (red, green, blue). This rotary filter 24 is provided with a filter driving motor 2.
5. Note that this filter drive motor 2
5 is connected to the control unit 27. And the control unit 2
Reference numeral 7 controls the filter drive motor 25 to rotate the rotary filter 24 at a constant speed, so that the RGB filters are sequentially inserted into the optical path.

The condenser lens 26 converges the light transmitted through the rotary filter 24 on the incident surface of the light guide 12. That is, the R light, the G light, and the B light are
It will be incident in order. The incident light is guided by the light guide 12, proceeds, and is emitted from the light distribution lens 11. That is, from the light distribution lens 11, the respective illumination lights of the R light, the G light, and the B light are sequentially emitted.

For this reason, in a state where the distal end portion of the endoscope 1 is arranged to face the subject, the R, G, and B lights emitted from the light distribution lens 11 are reflected by the subject. , And sequentially enters the objective lens 13. Then, the incident light is converged by the objective lens 13 and enters the broadband laser cut filter 14. As will be described later, the broadband laser cut filter 14 transmits visible light with almost no reduction.
Light emitted from the CCD 15 is hardly reduced.
Is formed in the vicinity of the image pickup plane. For this reason, the subject image by the R light, the G light, and the B light is sequentially formed on the imaging surface of the CCD 15.

The control unit 27 controls the CCD 15 via a signal line.
Is connected to Then, the CCD 15 outputs R light, G light,
The subject image by the light and the B light is sequentially converted into an image signal and transmitted to the control unit 27. The control unit 2 processes the image signals acquired during the R light emission period, the G light emission period, and the B light emission period to generate a color image signal. In addition,
The endoscope apparatus has a monitor (not shown) connected to the control unit 27. Then, the control unit 27 transmits the generated color image signal to the monitor, and causes the monitor to display the color image of the subject as a moving image.

Next, the laser treatment apparatus 3 will be described. This laser treatment device 3 has a laser light source 31 that emits a semiconductor laser, and a laser probe 32. The laser probe 32 guides a laser beam emitted from the laser light source 31 and emits the laser beam from its tip. In addition,
The laser probe 32 is drawn through the forceps insertion hole of the endoscope 1 into the insertion portion, and the tip of the laser probe 32 projects from the forceps hole at the tip of the endoscope 1.

Then, the surgeon identifies the affected part requiring treatment while observing the subject with the monitor in a state where the distal end of the endoscope 1 faces the subject. Then, the surgeon treats the affected part by causing the tip of the laser probe 32 to face the specified affected part and emitting a laser beam from the tip of the laser probe 32.

The laser beam emitted from the laser probe not only cuts and coagulates the affected part, but also enters the objective lens 13 as reflected light. However, the reflected light of the laser beam is reduced by the broadband laser cut filter 14. Hereinafter, the broadband laser cut filter 14 will be described with reference to Table 1.

[0030]

[Table 1] The broadband laser cut filter 14 is composed of one white sheet glass (refractive index: 1.520, thickness 1 mm or less) as a substrate, and a multilayer film formed on the surface of the white sheet glass. I have. This vapor-deposited film is a 54-layer film formed by alternately vapor-depositing a substance having a refractive index of 2.347 and a substance having a refractive index of 1.469.

FIG. 2 is a graph showing the spectral transmission characteristics of the broadband laser cut filter 14. As shown in FIG. 2, this broadband laser cut filter 14
Can reduce light in a wide wavelength range within the near infrared range. By comparing FIG. 2 with FIG. 5, it is understood that the broadband laser cut filter 14 can reduce near-infrared light in a wider range than the conventional laser cut filter.

FIG. 3 is a graph showing the spectral transmission characteristics of the infrared cut filter 22. As shown in FIG. 3, this infrared cut filter 22 can also reduce infrared light in a wider wavelength range than a conventional laser cut filter. However, as described below, this infrared cut filter 22 cannot be used as a laser cut filter. FIG. 4 shows the spectral transmission characteristics of the broadband laser cut filter 14 and the infrared cut filter 2.
2 is a graph showing the spectral transmission characteristics of No. 2;

As shown in FIG. 4, in the wavelength range from 800 nm to 1070 nm, the spectral transmittance of the infrared cut filter 22 is 0.1% or more, but the spectral transmittance of the broadband laser cut filter 14 is not less than 0.1%. The rate is 0.0
It is less than 5%. Therefore, if the objective lens 13
An infrared cut filter 22 on the optical path between
Is inserted, the infrared cut filter 22
Cannot reduce the light emitted from the laser probe 32 and reflected by the subject to a sufficient level.

On the other hand, the endoscope apparatus of the present embodiment
Since the broadband laser cut filter 14 is inserted on the optical path between the objective lens 13 and the CCD 15, light emitted from the laser probe 32 and reflected by the subject can be sufficiently reduced. Therefore, even when the laser beam is emitted from the laser probe 32, the CCD 15 normally generates an image signal. Therefore, the control unit 27 can display the subject image on the monitor even during the laser treatment.

In the above description, a semiconductor laser is used as the laser treatment device 3, but a YAG laser or other near-infrared laser may be used instead. That is, the broadband laser cut filter 14 is
In almost all wavelength ranges of near-infrared lasers used for medical purposes, the transmittance is 0.05% or less, so the operator can use a semiconductor laser, a YAG laser, and other near-infrared lasers for medical use. Can be freely selected and used according to the purpose and situation.

This endoscope apparatus is always provided with a medical near-infrared laser,
A normal subject image can be displayed on the monitor. Therefore, the surgeon can always perform the treatment while observing the subject. Further, the laser cut filter 14
Is 1 mm or less in thickness, the distal end of the endoscope 1 is configured to be short and compact.

[0037]

The broadband laser cut filter according to the present invention configured as described above can reduce the near-infrared laser used for medical purposes. Therefore, the endoscope apparatus having the broadband laser cut filter can acquire an image of the subject even when various medical near-infrared lasers are emitted to the subject.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an endoscope apparatus according to an embodiment of the present invention.

FIG. 2 is a graph showing a spectral transmission characteristic of a broadband laser cut filter.

FIG. 3 is a graph showing a spectral transmission characteristic of an infrared cut filter.

FIG. 4 is a diagram illustrating a comparison between a broadband laser cut filter and an infrared cut filter.

FIG. 5 is a graph showing the spectral transmission characteristics of a conventional laser cut filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Endoscope 13 Objective lens 14 Broadband laser cut filter 15 CCD area sensor 32 Laser probe

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiro Yamada 2-36-9 Maeno-cho, Itabashi-ku, Tokyo Asahi Gaku Kogyo Co., Ltd. F-term (reference) 2H040 BA14 CA22 DA56 GA02 2H048 GA01 GA14 GA36 GA53 4C026 AA01 BB07 FF32 FF53 FF55 FF58 GG06 HH23 4C061 CC06 FF40 FF47 HH56 LL01 MM03 NN01 PP12 RR04 RR14

Claims (5)

[Claims] An image pickup device is disposed on an optical path between an image pickup device and an objective lens for forming an image of a subject on the image pickup device. The light transmittance in a wavelength range of 800 nm to 1070 nm is 0.05% or less. A broadband laser cut filter characterized by having visible light transmitted therethrough. 2. The broadband laser cut filter according to claim 1, wherein the filter is formed in a single plate having a thickness of 1 mm or less. 3. The broadband laser cut according to claim 1, wherein an image pickup device, an objective lens for forming an image of a subject on the image pickup device, and an optical path between the objective lens and the image pickup device are provided. An endoscope device comprising a filter. 4. The apparatus according to claim 3, wherein the image pickup device, the broadband laser cut filter, and the objective lens are disposed in a distal end fixed to a distal end of an insertion portion to be inserted into a living body. Endoscope device. 5. The endoscope apparatus according to claim 3, further comprising a laser probe that emits a laser beam having a wavelength in a wavelength range from 800 nm to 1070 nm.