KR102056908B1 - Non-contacted axial resolution measuring apparatus of objective lens for confocal endo-microscope - Google Patents

Abstract

The present invention relates to a non-contact vertical resolution measuring device of an object lens for a confocal endoscopic microscope capable of measuring a vertical resolution of an ultra-small object lens used in a medical endoscopic microscope without damage in a non-contact manner, and evaluating a performance of the object lens based on thereof. The vertical resolution measuring device of the present invention comprises: a fixed jig for fixing the object lens to be tested and a relay lens for relaying a focus of the object lens; a mirror for reflecting an incident light while being finely moved in a Z-axis direction at one end of the fixing jig; a sensor for detecting an amount of light changed according to a change of position of the mirror; and a control IC for measuring the vertical resolution of the object lens on the basis of the light amount change data of the sensor.

Description

Non-contacted axial resolution measuring apparatus of objective lens for confocal endo-microscope

The present invention relates to an objective lens for confocal endoscopy, and more particularly, to measure the vertical resolution of a confocal endoscope microscope lens mounted on a medical probe inserted into a human body, without contactlessly damaging the performance of the objective lens. An apparatus for measuring vertical resolution of an objective lens that can be evaluated.

Confocal microscope is a microscope with depth resolution. It is used to observe the three-dimensional microstructure of semiconductor component materials in addition to cell structure research. It refers to a microscope that can acquire a high resolution image of the unit and diagnose the disease early. The confocal endoscope microscope refers to a high resolution endoscope microscope capable of acquiring three-dimensional images by integrating the confocal function and the function of the endoscope microscope.

The objective lens 10 is assembled to the lens housing as shown in Figure 1, the medical objective lens is mounted in front of the endoscope to observe the polyp formed in the organs such as esophagus, large intestine, etc. Resolution is a very important factor. In other words, it can be said that the performance of the medical endoscope is determined by the performance of the objective lens.

Therefore, it is very important to mount an objective lens that satisfies the initial design performance to a medical probe such as an endoscope. Because the objective lens is very small, it is very difficult to attach and detach the medical probe. If the objective lens coupled to the medical probe does not meet the performance and wants to be removed for repair, there is a reason for loss due to the very small size.

For this reason, performance evaluation of an objective lens mounted on an actual medical probe should be made in advance.

However, there have been no devices or methods for evaluating the performance of such miniature objective lenses. The performance evaluation of the objective lens can be made in measuring the vertical resolution, and therefore should be measured while moving the mirror in the front-back direction at the focus of the medical objective lens. However, when the vertical resolution of the objective lens is measured, the working distance is very short, about tens to hundreds of micrometers, which may damage the objective lens by contacting the objective lens while the mirror moves. It is very difficult to repair a very small medical objective lens in case of damage.

In addition, since the performance evaluation of the objective lens was difficult for the manufacturer of the objective lens, the objective lens was satisfactorily satisfied as intended even though the entire component of the medical probe or the endoscope microscope did not operate normally due to a defect in other components or components. It was true that the argument for providing performance was difficult.

Therefore, the need for a method of measuring and evaluating the vertical resolution of an objective lens used in a medical confocal endoscope has been steadily raised.

Accordingly, an object of the present invention is to solve the above problems, and to measure the vertical resolution of the ultra-compact objective lens used in the medical endoscope without contact damage without damage and to evaluate the performance of the objective lens based on this objective lens It is to provide a vertical resolution measuring device of.

In addition, this purpose is to effectively test the objective lens manufacturer by mounting the objective lens in the endoscope after being tested and evaluated in advance whether the objective lens satisfies the desired performance.

The present invention for achieving the above object is a light source; A polarization beam splitter (PBS) for transmitting only P waves of incident light generated from the light source; A second lens group for entering the transmitted P-wave incident light into an objective lens installed in a fixed jig; A mirror reflecting the P-wave incident light passing through the second lens group while moving in the z-axis direction by an actuator to measure the resolution of the objective lens; A fourth lens group positioned between the objective lens and the mirror to relay a focus position of the objective lens; A wavelength plate converting the P-wave reflected light reflected by the mirror into the S-wave reflected light and transferring it to the polarization beam splitter; A third lens group for focusing the S-wave reflected light reflected at a predetermined angle by the dividing surface of the polarizing beam splitter; A pin hole passing through the S-wave reflected light focused by the third lens group and having a specific size determined for measuring vertical resolution of the objective lens; A sensor for detecting a change in the amount of light of the S-wave reflected light transmitted through the pin hole according to a change in position of the mirror; And a control IC measuring a vertical resolution of the objective lens based on the light amount change data sensed by the sensor.

A first lens group for converting the incident light generated by the light source in parallel may be further included.

A polarizer for polarizing the incident light may be further included between the first lens group and the polarization beam splitter.

An aperture diaphragm or a ND filter (neutral density filter) for adjusting the light amount of the incident light may be further located at the front or rear end of the polarizer.

The first lens group includes a collimator lens in which one or more lenses are combined for parallel light, the second lens group includes an aspherical lens, and the third lens group includes one or more combined lenses for focusing. Here, the second lens group may be a combination of one or more lenses matching a vergence suitable for the objective lens.

The mirror moves while being spaced apart from one end of the fourth lens group.

According to the non-contact vertical resolution measuring device of the confocal endoscope microscope of the present invention as described above, by providing a device for measuring the non-contact vertical resolution of the microscopic objective lens used in the medical endoscope microscope, It can be installed in products such as medical probes after being tested and evaluated in advance without damaging the objective lens.

Therefore, it is possible to evaluate the performance of the objective lens before mounting on the medical probe.

In addition, since the objective lens, which has been evaluated for performance, is mounted on the medical probe, even if malfunctions or defects are caused by other components of the medical probe, there is also a possibility of minimizing damages only to the objective lens manufacturer.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a perspective view of a medical miniature objective lens for explaining the present invention
2 is an overall configuration diagram of a non-contact vertical resolution measuring apparatus of the objective lens for confocal endoscopy according to a preferred embodiment of the present invention
3 is an actual configuration of the non-contact vertical resolution measuring apparatus of FIG.
4 is an exemplary graph showing a vertical resolution measurement result of a general confocal microscope

DETAILED DESCRIPTION The following detailed description of the invention refers to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention are different, but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein may be embodied in other embodiments without departing from the spirit and scope of the invention with respect to one embodiment. In addition, it is to be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention, if properly described, is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled. Like reference numerals in the drawings refer to the same or similar functions throughout the several aspects.

The present invention proposes an apparatus for measuring vertical resolution of an objective lens for an endoscope microscope that can measure the vertical resolution of an ultra-small objective lens used in a medical endoscope microscope and evaluate the performance thereof. The invention will be described in more detail.

In the vertical resolution measuring apparatus 100, various lens groups, filters, and mirrors are disposed along a moving path of a light source, and a sensor measuring vertical resolution is disposed in a vertical direction in a moving path of light. In addition, in the description of the present invention, the light transmitted from the light source to the mirror will be referred to as incident light, and the light reflected from the mirror will be referred to as reflected light.

2 and 3, the vertical resolution measuring apparatus 100 includes a light source 101, a collimator lens 110, a polarizer 120, and a polarization beam splitter (PBS). beam spliter 130, waveplate 140, aspheric lens 150, test objective 160 and fixed jig 300 equipped with objective lens, relay optics (relay optics) module 200, the mirror 170 is disposed, the focusing lens 180, the pinhole 190, the sensor 400 in the vertical direction in the polarization beam splitter 130 is arranged in order . Also included is a control IC 500 that measures the vertical resolution of the objective lens 160 based on the information measured by the sensor 400.

In the drawing, light generated from the light source 101 is transmitted from left to right, and the coordinate system is in the + Z axis direction.

The configuration of the vertical resolution measuring apparatus 100 will be described. The light source 101 may be a fiber laser, a laser, an LED, or the like. In this embodiment, an optical fiber laser is used.

The collimator lens 110 converts the incident light irradiated by the fiber laser 101 in parallel. That is, the collimator lens 110 is configured to include a plurality of lens groups to allow incident light to be incident in parallel to the polarization beam splitter 130. In the embodiment, this is called a first lens group. The lenses and shapes included in the first lens group may vary according to the type of the light source 101.

In the present invention, such a first lens group does not necessarily need to be installed. In other words, since the embodiment uses a fiber laser, a collimator lens for converting in parallel is required, but it is not necessary to convert the incident light in the form of parallel light by using another light source.

The polarizer 120 that receives incident light in parallel from the collimator lens 110 generates polarized light of the incident light. In place of the polarizer, the ND filter 120 which reduces the amount of incident light may be used. In addition, the ND filter 120 and the polarizer may be used together. The location does not matter if the two configurations are used together. That is, it is possible to arrange the ND filter in front of or behind the polarizer 120.

The polarizing beam splitter 130 has a polarizing beam splitting surface 132 and is a light splitting element that splits a light source according to the polarization component of incident light. According to the exemplary embodiment, the polarization beam splitter 130 passes only P-primary waves along the Z axis. That is, the incident light incident on the polarization beam splitter 130 is a non-polarized state, but transmits only P waves. Light transmitted through only P waves is called P-wave incident light.

The wavelength plate 140 uses a 1/4 lambda wavelength plate and serves to form left circle polarization by rotationally polarizing P-wave incident light. That is, it functions as a phase retarder that causes the polarization of the light source to be incident (i.e., incident light) and reflected again (i.e., reflected light) to be switched. Therefore, as will be described below, the reflected light is converted into the S wave at the wavelength plate 140, and because of the S py, the reflected light may not be transmitted through the polarization beam splitter 130 and may be reflected from the dividing surface 132 toward the sensor 400. .

Aspheric lens 150 is a second lens group for producing light suitable for the objective lens.

The fixing jig 300 is a mechanism for fixing the test objective lens 160. The fixing jig 300 should have a fixed state of the objective lens 160 while measuring the vertical resolution of the objective lens 160 and manufactured accordingly. In the embodiment, the fixing jig 300 is formed to protrude in a form surrounding the fixing plate 301 of a predetermined length, the through hole 302 through which P-wave incident light passes, and the through hole 302 on one surface of the fixing plate 301. And a holder part 303 which substantially fixes the objective lens 160. The holder portion 303 may be manufactured in any configuration that can be fixed without damaging the objective lens.

According to the present embodiment, the holder part 303 has a predetermined length. Preferably, when the objective lens 160 is fixed, the length of the objective lens 160 to prevent the lens on the outermost side (ie, opposite the fixing plate) from directly contacting the relay optical module 200 or the mirror 170. It may be better to stay the same or slightly longer.

The relay optics module 200 includes one or more combined lenses to relay the focusing position of the objective lens 160 and will be referred to as a fourth lens group. The relay optical module 200 is necessary for measuring vertical resolution without damage when the working distance is very short, such as an objective lens for a confocal endoscopy microscope, and has a long working distance. It does not need to be used to measure the lens.

The mirror 170 is configured to be moved in the left and right directions (ie, the Z-axis position change) for measuring the vertical resolution of the objective lens 160. This mirror 170 is installed in the dark room 171 as shown in FIG. Although not shown in the drawing, an actuator for moving the mirror 170 should be configured. This actuator is driven under the control of the control IC 500 described later.

The focusing lens 180 focuses the focus of the S-wave reflected light reflected from the mirror 170 to the pinhole 190. Therefore, two or more lenses are used for various focusing and will be referred to as a third lens group. The focusing lens 180 moves in the vertical direction in the drawing for the focusing. In this case, the P-wave reflected light reflected from the mirror 170 is converted into the S-wave reflected light from the wavelength plate 140, and the S-wave reflected light is reflected from the dividing surface 132 of the polarization beam splitter 130 to the focusing lens 180. You are guided.

The pinhole 190 may be a hole through which the S-wave reflected light passes, and may have a specific size determined for measuring the vertical resolution of the objective lens 160. For example, the size of the pinhole 190 may be a length of the diameter of the pinhole 190. The pinhole 190 is disposed in front of the sensor 400.

The sensor 400 detects the degree of change in the amount of light so that the vertical resolution can be measured using the S-wave reflected light reflected and transmitted from the mirror 170 as the mirror 170 moves. The amount of light detected by the sensor 400 may be determined based on the size of the pinhole 190.

The control IC 500 measures the vertical resolution of the objective lens 160 using the information detected by the sensor 400.

Next, an operation of measuring the vertical resolution of the objective lens 160 using the vertical resolution measuring apparatus 100 having such a configuration will be described. In order to measure the vertical resolution, the objective lens 160 to be tested is first fixed to the holder 303 of the fixing jig 300.

If the laser light is generated from the light source 101 while moving the mirror 170 in the Z-axis direction in this state, the laser incident light is incident on the collimator lens (first lens group 110).

The collimator lens 110 changes the incident light generated by the light source 101 in parallel and transmits the light to the polarizer 120. Then, the polarizer 120 creates the polarization of the light source. In this case, the ND filter may be positioned at the front end or the rear end of the polarizer 120. Therefore, the amount of light of the light source can be reduced to some extent by the ND filter. The reason for adjusting the amount of light is that if a large amount of light is applied to the sensor 400, the sensor 400 may be damaged and may not function properly. At this time, since the ND filter serves to adjust the amount of light, the aperture stop may be provided to adjust the amount of light.

However, according to the present exemplary embodiment, the configuration of the polarizer 120, the ND filter, and the aperture is not necessarily required. Therefore, incident light emitted from the collimator lens 110 may be directly transmitted to the polarization beam splitter 130.

The incident light is transmitted through the polarization beam splitter 130 to transmit the P-wave only to the wavelength plate 140, and the left circularly polarized light is formed on the wavelength plate 140 and transmitted to the aspherical lens (second lens group 150). The aspherical lens 150 generates incident light suitable for the objective lens 160 and guides the objective lens 160 to the test objective lens 160. The incident light passing through the objective lens 160 passes through the relay optical module (fourth lens group 200). Passed to and transmitted to the mirror 170.

Since the mirror 170 is changed in position in the Z-axis direction by the actuator, the reflected light reflected from the mirror 170 will change according to the position change of the mirror 170 when it is transmitted to the sensor 400. . The reflected light is transmitted to the wavelength plate 140 through the relay optical module 200, the objective lens 160, the aspherical lens 150 in a direction opposite to the transmission path of the incident light, and the P wave at the wavelength plate 140 is S Since the wave is converted into a wave, the S wave in the polarization beam splitter 130 is reflected corresponding to the angle of the dividing surface 132. The reflected S-wave reflected light is incident on the sensor 400 through the focusing lens (third lens group 180) and the pinhole 190.

As such, the sensor 400 continuously receiving the reflected light in which the amount of light changes according to the positional change of the mirror 170 may detect a change state of the amount of light. That is, while the mirror 170 is moving, it is possible to detect the extent that the amount of light decreases when the position is changed in the z-axis direction assuming that the light amount is at the peak when the mirror 170 is in the focal position.

The control IC 500 fits the data sensed by the sensor 400 into a Gaussian distribution to calculate a full width at half maximum (FWHM). An example of the measurement result of the half width is as shown in FIG. 4. 4 is a measurement result of the vertical resolution of a general confocal microscope, the control IC 500 of the present embodiment also based on the light amount change data detected by the sensor 400 by the movement of the mirror 170 and FIG. By creating the same graph and calculating the half width, the vertical resolution can be measured.

As described above, the present invention uses a non-contact vertical resolution measuring apparatus 100 equipped with a fixing jig 300 to which the objective lens 160 can be coupled without damaging the performance of the objective lens 160 to be mounted on the medical endoscope microscope. Since it can be tested and evaluated in advance, it can be seen that the objective lens showing the desired performance can be used, and thus, sufficient performance of the medical endoscope microscope can be guaranteed.

Although described with reference to the illustrated embodiment of the present invention as described above, this is merely exemplary, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the invention It will be apparent that other variations, modifications and equivalents are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

100: vertical resolution measuring device 101: light source
110: collimator lens (first lens group) 120: polarizer
130: polarization beam splitter (PBS) 140: wavelength plate
150: aspherical lens (second lens group) 160: test objective lens
170: mirror 171: darkroom
180: focusing lens (third lens group) 190: pinhole
200: relay optical module (fourth lens group) 300: fixing jig 301: fixing plate 302: through hole 303: holder 400: sensor
500: control IC (500)

Claims (5)

Light source;
A polarization beam splitter (PBS) for transmitting only P waves of incident light generated from the light source;
A second lens group for entering the transmitted P-wave incident light into an objective lens installed in a fixed jig;
A mirror reflecting P-wave incident light passing through the second lens group while moving in a z-axis direction to measure the resolution of the objective lens;
An actuator for moving the mirror;
A fourth lens group positioned between the objective lens and the mirror and including one or more combined lenses to relay a focal position of the objective lens;
A wavelength plate converting the P-wave reflected light reflected by the mirror into the S-wave reflected light and transferring it to the polarization beam splitter;
A third lens group for focusing the S-wave reflected light reflected at a predetermined angle by the dividing surface of the polarizing beam splitter;
A pin hole passing through the S-wave reflected light focused by the third lens group and having a specific size determined for measuring vertical resolution of the objective lens;
A sensor for detecting a change in the amount of light of the S-wave reflected light transmitted through the pin hole according to a change in position of the mirror; And
Non-contact vertical resolution measuring device of the confocal endoscope microscope including a control IC for measuring the vertical resolution of the objective lens based on the light amount change data sensed by the sensor. The method of claim 1,
Non-contact vertical resolution measuring device of the confocal endoscope objective lens further comprises a first lens group for converting the incident light generated in the light source in parallel. The method of claim 2,
Non-contact vertical resolution measuring device of the objective lens for a confocal endoscope microscope further comprises a polarizer for polarizing the incident light between the first lens group and the polarizing beam splitter. The method of claim 3, wherein
Non-contact vertical resolution measuring device of the confocal endoscope microscope for the aperture or ND filter (neutral density filter) for adjusting the light amount of the incident light at the front or rear end of the polarizer. The method of claim 2,
The first lens group is a collimator lens in which one or more lenses are combined for parallel light, the second lens group is an aspherical lens, and the third lens group includes one or more combination lenses for focusing. Non-contact vertical resolution measuring device of objective lens.

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