JP6484485B2 - Stripe scanning position compensation structure and endoscope apparatus having the same - Google Patents

Description

  The present invention projects the interference fringes formed by the interference fringe forming means through the fiber transmission path onto the object plane, and detects and corrects the displacement of the interference fringes due to the disturbance in the endoscope that scans the interference fringes. The present invention relates to a fringe scanning position compensation structure and an endoscope apparatus including the same.

  Conventionally, as an endoscope that projects interference fringes through a fiber transmission path, for example, there is an endoscope described in Patent Document 1 below.

JP-A-5-211988

  By the way, in the endoscope apparatus as described above, the rotation of the polarization plane is caused by changes in the external environment such as temperature and humidity, and physical stress that the fiber transmission path receives when the direction of the endoscope is changed. As a result, the phase of the interference fringe (the position of light and dark) changes, so the accuracy of the measurement value using the interference fringe cannot be guaranteed. However, the conventional endoscope apparatus accurately grasps the change in the phase of the interference fringes due to the change in the external environment and the physical stress as described above, and feeds back to the measurement value. It could not be fixed at the desired position.

  According to some aspects of the present invention, there has been proposed in order to solve the above-described conventional problems, and a fiber when the external environment such as temperature and humidity changes or the direction of the endoscope is changed. A fringe scanning position compensation structure capable of monitoring the phase shift (brightness / darkness position) of the interference fringes with respect to the physical stress applied to the transmission path, and further fixing the interference fringe position at a desired position; An object of the present invention is to provide an endoscope apparatus provided with the same.

  To achieve the above object, a fringe scanning position compensation structure according to an aspect of the present invention includes a laser light source, a polarization plane holding fiber that transmits light from the laser light source, and the polarization plane that is emitted from the laser light source. An endoscope for projecting the interference fringes formed by the projection interference fringe forming means on an object plane, comprising: an interference fringe forming means for forming an interference fringe using light passing through the holding fiber; An optical multiplexing / demultiplexing unit disposed between the polarization plane holding fiber and an optical path from the laser light source to enter the polarization plane holding fiber and to the incident plane of the projection interference fringe forming unit Return light information detecting means for detecting information on the return light reflected by a predetermined optical surface disposed on the optical path and passing through the optical multiplexing / demultiplexing means.

  An endoscope apparatus according to an aspect of the present invention includes a fringe scanning position compensation structure according to an aspect of the present invention.

  According to the present invention, the phase of the interference fringes (the position of light and darkness) shifts with respect to changes in the external environment such as temperature and humidity, and physical stress experienced by the fiber transmission path when the direction of the endoscope is changed. Further, a fringe scanning position compensation structure capable of fixing the position of the interference fringes at a desired position and an endoscope apparatus including the same are obtained.

It is explanatory drawing which shows schematic structure of the compensation structure of the fringe scanning position concerning 1st Embodiment of this invention. It is explanatory drawing which shows schematic structure of the compensation structure of the fringe scanning position concerning 2nd Embodiment of this invention, (a) is a figure which shows the example, (b) is a figure which shows another example. It is explanatory drawing which shows schematic structure of the compensation structure of the fringe scanning position concerning 3rd Embodiment of this invention, (a) is a figure which shows the example, (b) is a figure which shows another example. It is explanatory drawing which shows schematic structure of the compensation structure of the fringe scanning position concerning 4th Embodiment of this invention, (a) is a figure which shows the example, (b) is a figure which shows another example. It is explanatory drawing which shows schematic structure of the compensation structure of the fringe scanning position concerning 5th Embodiment of this invention. It is explanatory drawing which shows schematic structure of the compensation structure of the fringe scanning position concerning the modification of 4th Embodiment and 5th Embodiment of this invention, (a) is a figure which shows the modification of 4th Embodiment, (b) These are figures which show the modification of 5th Embodiment. It is explanatory drawing which shows schematic structure of the compensation structure of the fringe scanning position concerning 6th Embodiment of this invention. It is explanatory drawing which shows schematic structure of the compensation structure of the fringe scanning position concerning 7th Embodiment of this invention. It is explanatory drawing which shows schematic structure of the compensation structure of the fringe scanning position concerning 8th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described. The embodiment described below does not unduly limit the contents of the present invention described in the claims. In addition, all the configurations described in the following embodiments are not necessarily essential configuration requirements in the present invention.

  The compensation structure of the fringe scanning position according to the embodiment of the present invention uses a laser light source, a polarization plane holding fiber that transmits light from the laser light source, and light that is emitted from the laser light source and passes through the polarization plane holding fiber. An endoscope for projecting the interference fringes formed by the projection interference fringe forming means onto an object plane, wherein the laser light source and the polarization plane holding fiber are Optical multiplexing / demultiplexing means disposed between the optical source and the predetermined optical element disposed on the optical path from the laser light source to enter the polarization plane holding fiber and to the incident surface of the projection interference fringe forming means Return light information detection means for detecting information of the return light reflected by the surface and passed through the optical multiplexing / demultiplexing means.

  As a result of repeated trial and error studies, the inventor of the present invention provided a laser including a projection interference fringe forming unit that emits an interference fringe using light emitted from a laser light source and passed through the polarization plane holding fiber. Not all of the light emitted from the light source and passing through the polarization-maintaining fiber is emitted from the polarization-maintaining fiber toward the projection interference fringe forming means, but a part of the light reaches the incidence plane of the projection interference fringe forming means. Focusing on the fact that the light is reflected by a predetermined optical surface (for example, the exit surface of the polarization-maintaining fiber, etc.) disposed on the optical path and returns in the opposite direction, the information of this return light is detected. The compensation structure of the fringe scanning position was conceived.

  Like the fringe scanning position compensation structure of the embodiment of the present invention, the optical multiplexing / demultiplexing means disposed between the laser light source and the polarization-maintaining fiber, and the light emitted from the laser light source and incident on the polarization-maintaining fiber And return light information detecting means for detecting information of the return light reflected by a predetermined optical surface arranged on the optical path to the incident surface of the projection interference fringe forming means and passing through the optical multiplexing / demultiplexing means. In this case, for example, the return light information detecting means includes a monitor interference fringe forming means for forming an interference fringe using the return light, and an interference fringe detecting element for detecting the interference fringe formed by the monitor interference fringe forming means. By using the return light from the polarization plane holding fiber, the phase shift of the interference fringes that are emitted from the laser light source and formed through the projection plane fringe forming means via the polarization plane holding fiber is formed. The reference position of the interference fringe phase It can be grasped on the basis of the amount of deviation. In addition, since the return light is twice affected by the disturbance passing through the polarization-maintaining fiber, it is easy to clearly grasp the amount of deviation from the reference position of the phase of the interference fringes formed using the return light. Furthermore, if information on the return light from the polarization-maintaining fiber (for example, interference fringes formed using the return light) is detected, the information on the return light is displayed in the endoscope instead of the distal end portion of the endoscope. It can be grasped at the hand side of the mirror. And, for example, a phase shifter disposed between the laser light source and the polarization-maintaining fiber, and based on the amount of deviation from the reference position of the phase of the interference fringe formed using the return light, for example, By adjusting the phase shift amount via a phase shifter or the like on the hand side of the endoscope, the phase of the interference fringes projected on the object plane via the projection interference fringe forming means is adjusted to a desired position. Is possible. Further, for example, using the return light information detected by the return light information detection means, the amount of deviation from the reference position of the phase of the interference fringes formed by the projection interference fringe forming means is calculated, and the calculated deviation amount The phase of the interference fringes projected on the object plane via the projection fringe forming means can be fixed at a desired position by having a feedback controller that controls the driving amount of the phase shifter based on Become.

  Therefore, according to the fringe scanning position compensation structure of the embodiment of the present invention, the phase of the interference fringes projected on the object plane via the projection interference fringe forming means due to changes in the external environment or physical stress. Can be accurately grasped and fed back to the measurement value of the interference fringes projected on the object plane obtained via the measurement optical system provided in the endoscope, and the phase of the interference fringes can be obtained at a desired position. It becomes possible to fix to.

The fringe scanning position compensation structure according to the embodiment of the present invention preferably further includes a phase shifter disposed between the laser light source and the polarization-maintaining fiber.
In the fringe scanning position compensation structure according to the embodiment of the present invention, it is preferable that the projection interference fringe forming unit further uses the return light information detected by the return light information detecting unit. A feedback controller that calculates a shift amount of the phase of the interference fringe from the reference position and controls the drive amount of the phase shifter based on the calculated shift amount.
In this way, changes in the phase of the interference fringes projected onto the object plane via the projection interference fringe forming means due to changes in the external environment or physical stress can be grasped in real time, and the phase at which the drive amount is controlled The shifter can automatically adjust in real time so that the phase of the interference fringes is fixed at a desired position.

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

It is explanatory drawing which shows schematic structure of the compensation structure of the fringe scanning position concerning 1st Embodiment of this invention.
The endoscope including the fringe scanning position compensation structure 1-1 according to the first embodiment includes a laser light source 11, a polarization plane holding fiber 12, a projection interference fringe forming unit 13, and a projection lens. .
The polarization-maintaining fiber 12 is composed of a fiber having different refractive indexes in the vertical direction and the horizontal direction, for example, a so-called PANDA fiber, which keeps the polarization plane from rotating by an external force, and from the laser light source 11. Transmit light.
The projection interference fringe forming means 13 includes a birefringent plate 13a and a polarizing plate 13b.
The birefringent plate 13a is disposed on the exit end side of the polarization plane holding fiber 12, and divides and emits incident light into two linearly polarized light components having different polarization directions.
The polarizing plate 13b is disposed on the output end side of the birefringent plate 13a, and transmits only the light of the linearly polarized light component polarized in a specific direction among the incident light.
Then, the projection interference fringe forming means 13 forms an interference fringe using light emitted from the laser light source 11 and passed through the polarization plane holding fiber 12.
The projection lens 14 projects the interference fringes 50 formed by the projection interference fringe forming means 13 onto the object plane.
Although not shown, the endoscope includes a conventionally known measurement optical system. The measurement optical system is configured to acquire the interference fringe 50 projected on the object plane and measure the object plane based on the acquired information of the interference fringe 50.
The laser light source 11 is preferably composed of a laser diode with a Peltier element temperature controller. If the laser light source 11 is composed of a laser diode with a Peltier element temperature controller, the influence of temperature change is reduced and stable laser light in a constant state can be emitted.

The fringe scanning position compensation structure 1-1 according to the first embodiment includes an optical multiplexer / demultiplexer 15 as optical multiplexing / demultiplexing means, a monitor interference fringe forming means 16 as return light information detecting means, and interference fringes. A detection element 17 is provided.
The optical multiplexer / demultiplexer 15 is composed of a fiber coupler and is disposed between the laser light source 11 and the polarization-maintaining fiber 12.
The monitor interference fringe forming means 16 includes a birefringent element 16a and a polarizing plate 16b.
The birefringent plate 16a is disposed on the other optical path that is not optically connected to the laser light source 11 on the laser light source 11 side in the optical multiplexer / demultiplexer 15, and the incident light is polarized in the polarization direction. The light is divided into two different linearly polarized light components.
In the example of FIG. 1, the laser light source 11 is optically connected to one end of the optical multiplexer / demultiplexer 15 via the fiber 20, and the birefringent plate 16 a is optically multiplexed / demultiplexed via the fiber 21. It is optically connected to the other end of the device 15 on the laser light source 11 side.
The polarizing plate 16b is disposed on the exit end side of the birefringent plate 16a, and transmits only the light of the linearly polarized light component polarized in a specific direction among the incident light.
The monitor interference fringe forming means 16 emits from the laser light source 11 and enters the polarization plane holding fiber 12, and does not exit from the polarization plane holding fiber 12 but reflects from the emission end face. Interference fringes are formed using the light that has passed through.
The interference fringe detection element 17 is composed of a line sensor. Then, the interference fringe detecting element 17 detects the interference fringe 51 formed by the monitoring interference fringe forming means 16.
In addition, in the fringe scanning position compensation structure of the first embodiment, the interference fringe detection element 17 is connected to, for example, a display device (not shown), and the interference fringe 51 detected by the interference fringe detection element 17 is not shown. It is configured to display on the device.

Using the endoscope having the fringe scanning position compensation structure of the first embodiment configured as described above, the projection of the interference fringes on the object surface and the grasp of the phase change of the interference fringes are as follows. Done.
The light emitted from the laser light source 11 enters the polarization plane holding fiber 12 through the fiber 21 and the optical multiplexer / demultiplexer 15. The light incident on the polarization plane holding fiber 12 passes through the inside while being held so that the plane of polarization does not rotate, most of the light exits from the exit end, and enters the birefringent plate 13a. The light that has entered the birefringent plate 13a is divided into two linearly polarized light components having different polarization directions, and is emitted to enter the polarizing plate 13b. Of the light incident on the polarizing plate 13b, only the linearly polarized light polarized in a specific direction passes through the polarizing plate 13b. At this time, interference fringes 50 are formed.
The interference fringes 50 formed by passing through the polarizing plate 13b are projected onto an object plane (not shown) by the projection lens 14.

In addition, a small amount of light that has entered the polarization plane holding fiber 12 and has passed through the inside while reaching the output end while being held so that the polarization plane does not rotate is birefringent from the output end of the polarization plane holding fiber 12. The light is not emitted toward the plate 13a but is reflected at the emission end face.
The return light reflected by the exit end face of the polarization-maintaining fiber 12 follows the optical path in the opposite direction, exits from the end face on the optical multiplexer / demultiplexer 15 side, and enters the optical multiplexer / demultiplexer 15. Of the return light incident on the optical multiplexer / demultiplexer 15, the return light emitted from the end portion on the side optically connected to the birefringent plate 16a enters the birefringent plate 16a via the fiber 22. The return light that has entered the birefringent plate 16a is divided into two linearly polarized light components having different polarization directions and then exits and enters the polarizing plate 16b. Of the light incident on the polarizing plate 16b, only the linearly polarized light polarized in a specific direction passes through the polarizing plate 16b. At this time, interference fringes 51 are formed. The formed interference fringe 51 is detected by the interference fringe detection element 17 and displayed on a display device (not shown).

  According to the fringe scanning position compensation structure 1-1 of the first embodiment, the optical multiplexer / demultiplexer 15 disposed between the laser light source 11 and the polarization-maintaining fiber 12, and the laser light source emits the polarization. Return light information detecting means (monitor interference fringes) for detecting the information of the return light that has entered the wavefront holding fiber 12 and reflected from the output end face without exiting from the polarization holding fiber 12 and passed through the optical multiplexer / demultiplexer 15. The interference fringe 50 is emitted from the laser light source 11 and formed through the projection interference fringe forming means 13 via the polarization plane holding fiber 12. The phase shift can be grasped based on the shift amount from the reference position of the phase of the interference fringe 51 formed by using the return light from the polarization plane holding fiber 12 displayed on a display device (not shown). In addition, since the return light is twice affected by the disturbance passing through the polarization plane holding fiber 12, it becomes easy to clearly grasp the amount of deviation from the reference position of the phase of the interference fringe 51 formed using the return light. Further, since the interference fringe 51 formed using the return light is detected as the information on the return light from the polarization plane holding fiber 12, the information on the return light is displayed on the endoscope, not on the distal end portion of the endoscope. It can be grasped at the hand side of the mirror. And, for example, by having a phase shifter disposed between the laser light source and the polarization-maintaining fiber, based on the amount of deviation from the reference position of the phase of the interference fringe 51 formed using the return light, for example, The phase of the interference fringe 50 projected on the object plane via the projection interference fringe forming means 13 is adjusted to a desired position by adjusting the amount of phase deviation via a phase shifter or the like on the proximal side of the endoscope. It becomes possible to adjust to. Further, for example, the amount of deviation from the reference position of the phase of the interference fringe 50 formed by the projection interference fringe forming unit 13 is calculated by using the information of the return light detected by the return light information detection unit, and calculated. By having a feedback controller that controls the driving amount of the phase shifter based on the amount of deviation, the phase of the interference fringe 50 projected onto the object plane via the projection interference fringe forming means 13 is fixed at a desired position. It becomes possible.

  Therefore, according to the fringe scanning position compensation structure 1-1 of the first embodiment, the interference fringe 50 projected onto the object plane via the projection interference fringe forming means 13 due to a change in the external environment or physical stress. Can be accurately grasped and fed back to the measurement value of the interference fringe 50 projected on the object plane, which is obtained via a measurement optical system (not shown) provided in the endoscope. It becomes possible to fix the phase of the stripe 50 at a desired position.

In the above example, the light reflected by the exit end face without being emitted from the polarization plane holding fiber 12 to the return light to be formed with the interference fringe 51 by the monitoring interference fringe forming means 16 in the return light information detecting means. However, the return light from which the interference fringe 51 is formed by the monitoring interference fringe forming means 16 is reflected by a predetermined optical surface arranged on the optical path to the incident surface of the projection interference fringe forming means 13. Any light reflected by any optical surface can be applied.
For example, light reflected by the incident surface of the projection interference fringe forming unit 13 (here, the incident surface of the birefringent plate 13a) is converted into return light to be formed by the monitor interference fringe forming unit 16 as an interference fringe 51 formation target. It may be used. For example, when an optical member is disposed between the exit end face of the polarization-maintaining fiber 12 and the incident face of the projection interference fringe forming means 13, the light reflected by the entrance face or the exit face of the optical member is reflected. Alternatively, it may be used for the return light that is the target for forming the interference fringe 51 by the monitoring interference fringe forming means 16.

Second Embodiment FIGS. 2A and 2B are explanatory views showing a schematic configuration of a fringe scanning position compensation structure according to a second embodiment of the present invention. FIG. 2A is a diagram showing an example thereof, and FIG. 2B is a diagram showing another example. . In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.
The fringe scanning position compensation structure 1-2 in the example of FIG. 2A further includes a phase shifter 18 in addition to the configuration of FIG.
The phase shifter 18 is disposed between the laser light source 11 and the optical multiplexer / demultiplexer 15.
Other configurations are substantially the same as the fringe scanning position compensation structure 1-1 of the first embodiment shown in FIG.
The compensation structure 1-2 ′ for the fringe scanning position in the example of FIG. 2B further includes a feedback controller 19 in addition to the configuration of FIG.
The feedback controller 19 uses the position information of the interference fringe 51 as the information of the return light detected by the return light information detection means (monitoring interference fringe forming means 16 and interference fringe detection element 17), and uses the interference fringe for projection. A shift amount from the reference position of the phase of the interference fringe 50 formed by the forming unit 13 is calculated, and the drive amount of the phase shifter 18 is controlled based on the calculated shift amount.

According to the fringe scanning position compensation structure 1-2 in FIG. 2 (a), the phase shifter 18 disposed between the laser light source 11 and the optical multiplexer / demultiplexer 15 is configured. The phase shifter 18 is driven in accordance with the amount of deviation from the reference position of the phase of the interference fringe 51 as information of the return light detected by the optical information detection means (the interference fringe forming means 16 for monitoring, the interference fringe detection element 17). Thus, the phase deviation of the interference fringe 51 from the reference position can be corrected, thereby adjusting the phase of the interference fringe 50 projected on the object plane via the projection interference fringe forming means 13 to a desired position. it can.
According to the fringe scanning position compensation structure 1-2 ′ of FIG. 2B, the interference fringes 50 projected onto the object plane via the projection interference fringe forming means 13 due to changes in the external environment or physical stress. The phase change can be grasped in real time, and the phase shifter 18 whose drive amount is controlled can be automatically adjusted in real time so that the phase of the interference fringe 50 is fixed at a desired position.
The phase shifter 18 is driven not only to correct the phase shift of the interference fringe 51 from the reference position as described above, but also to change the phase of the interference fringe 50 projected onto the object plane by 90 degrees, for example. It can also be used to shift and scan the object plane.
However, according to the fringe scanning position compensation structure 1-2 ′ of FIG. 2B, when the object plane is scanned through the phase shifter 18, the deviation of the phase of the interference fringe 51 from the reference position is corrected. However, the phase of the interference fringe 50 can be shifted to a desired position.
Other functions and effects are substantially the same as the fringe scanning position compensation structure 1-1 of the first embodiment shown in FIG.

Third Embodiment FIG. 9 is an explanatory diagram showing a schematic configuration of a fringe scanning position compensation structure according to a third embodiment of the present invention, in which (a) is a diagram illustrating an example thereof, and (b) is a diagram illustrating another example. . In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.
The fringe scanning position compensation structure 1-3 in the example of FIG. 3A further includes a phase shifter 18 ′ in addition to the configuration of FIG.
The phase shifter 18 ′ is disposed between the optical multiplexer / demultiplexer 15 and the polarization-maintaining fiber 12.
The fringe scanning position compensation structure 1-3 ′ of the example of FIG. 3B further includes a feedback controller 19 ′ in addition to the configuration of FIG.
The feedback controller 19 ′ uses the position information of the interference fringe 51 as the information of the return light detected by the return light information detecting means (the interference fringe forming means 16 for monitoring, the interference fringe detecting element 17). The amount of deviation from the reference position of the phase of the interference fringe 50 formed by the fringe forming means 13 is calculated, and the drive amount of the phase shifter 18 ′ is controlled based on the calculated amount of deviation.
Other configurations are substantially the same as the fringe scanning position compensation structure 1-1 of the first embodiment shown in FIG.

According to the fringe scanning position compensation structure 1-3 in FIG. 3A, the phase shifter 18 ′ disposed between the optical multiplexer / demultiplexer 15 and the polarization-maintaining fiber 12 is configured. Therefore, in accordance with the amount of deviation from the reference position of the phase of the interference fringe 51 as the information of the return light detected by the return light information detecting means (monitor interference fringe forming means 16, interference fringe detecting element 17), the phase shifter 18 'can be driven to correct the phase shift of the interference fringe 51 from the reference position, whereby the phase of the interference fringe 50 projected onto the object plane via the projection interference fringe forming means 13 is desired. The position can be adjusted.
According to the fringe scanning position compensation structure 1-3 ′ of FIG. 3B, the interference fringes 50 projected onto the object plane via the projection interference fringe forming means 13 due to changes in the external environment or physical stress. The phase change can be grasped in real time, and the phase shifter 18 'whose drive amount is controlled can be automatically adjusted in real time so that the phase of the interference fringe 50 is fixed at a desired position.
The phase shifter 18 ′ is driven to correct the phase shift of the interference fringe 51 from the reference position as described above, and the phase of the interference fringe 50 projected onto the object plane is set to 90 degrees, for example. It can also be used to scan the object plane by shifting each time.
However, according to the fringe scanning position compensation structure 1-3 ′ of FIG. 3B, the phase deviation of the interference fringe 51 from the reference position is corrected when the object plane is scanned through the phase shifter 18 ′. However, the phase of the interference fringe 50 can be shifted to a desired position.
Other functions and effects are substantially the same as the fringe scanning position compensation structure 1-1 of the first embodiment shown in FIG.

Fourth Embodiment FIGS. 4A and 4B are explanatory views showing a schematic configuration of a fringe scanning position compensation structure according to a fourth embodiment of the present invention. FIG. 4A shows an example thereof, and FIG. 4B shows another example. FIG. In addition, about the structure similar to 3rd Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.
In addition to the configuration of FIG. 3A, the fringe scanning position compensation structure 1-4 in the example of FIG. 4A further includes a second laser light source 23 and second optical multiplexing / demultiplexing means. The second optical multiplexer / demultiplexer 24 is configured.
The second laser light source 23 is configured to emit light having a wavelength λ2 that is longer than the light having the wavelength λ1 emitted from the laser light source 11.
The second optical multiplexer / demultiplexer 24 is disposed between the laser light source 11 and the second laser light source 23 and the optical multiplexer / demultiplexer 15. The laser light source 11 and the second laser light source 23 are optically connected to different end portions on the same side in the second optical multiplexer / demultiplexer 24, respectively.
The fringe scanning position compensation structure 1-4 ′ in the example of FIG. 4B further includes a feedback controller 19 ″ in addition to the configuration of FIG.
The feedback controller 19 ″ emits from the second laser light source 23, enters the polarization plane holding fiber 12 through the second optical multiplexer / demultiplexer 24, the optical multiplexer / demultiplexer 15, and the phase shifter 18 ′. The reflected light is not emitted from the polarization plane holding fiber 12 but reflected by the emission end face, and the interference fringe 51 is formed by the monitor interference fringe forming means 16 via the phase shifter 18 ′ and the optical multiplexer / demultiplexer 15. Using the phase information of the interference fringe 51 detected by the interference fringe detection element 17, the amount of deviation from the reference position of the phase of the interference fringe 50 formed by the projection interference fringe forming means 13 is calculated, and the calculated amount of deviation Is configured to control the driving amount of the phase shifter 18 ′.
Other configurations are substantially the same as the fringe scanning position compensation structures 1-3 and 1-3 ′ of the third embodiment shown in FIGS. 3 (a) and 3 (b).

With the fringe scanning position compensation structures 1-4 and 1-4 ′ of the fourth embodiment configured as described above, when grasping the phase change of the interference fringe 50 projected onto the object plane, the second The laser light source 23 is turned on and the laser light source 11 is turned off.
The light emitted from the second laser light source 23 enters the polarization plane holding fiber 12 through the second optical multiplexer / demultiplexer 24, the optical multiplexer / demultiplexer 15, and the phase shifter 18 ′. Of the light that is incident on the polarization-maintaining fiber 12 and passes through the interior and reaches the output end while being held so that the polarization plane is not rotated, a small amount of light is transmitted from the output end of the polarization-maintaining fiber 12 to the birefringent plate 13a. Reflected at the exit end face without exiting toward.
The return light reflected by the exit end face of the polarization-maintaining fiber 12 follows the optical path in the opposite direction, exits from the end face on the phase shifter 18 'side, and enters the optical multiplexer / demultiplexer 15 through the phase shifter 18'. Of the return light incident on the optical multiplexer / demultiplexer 15, the return light emitted from the end on the birefringent plate 16 a side passes through the fiber 22, the birefringent plate 16 a, and the polarizing plate 16 b, thereby causing the interference fringe 51 to pass. Form. The formed interference fringe 51 is detected by the interference fringe detection element 17 and displayed on a display device (not shown).
Further, in the fringe scanning position compensation structure 1-4 ′ of FIG. 4B, the feedback controller 19 ″ uses the phase information of the interference fringe 51 detected by the interference fringe detection element 17 to project the interference fringe for projection. The amount of deviation from the reference position of the phase of the interference fringe 50 formed by the forming means 13 is calculated, and the drive amount of the phase shifter 18 ′ is controlled based on the calculated amount of deviation. The positional deviation of the phase when 50 is projected is corrected in real time.

When the interference fringe 50 is projected onto the object surface, the second laser light source 23 is turned off and the laser light source 11 is turned on.
The light emitted from the laser light source 11 enters the polarization plane holding fiber 12 through the optical multiplexer / demultiplexer 24, the optical multiplexer / demultiplexer 15, and the phase shifter 18 ′. The light incident on the polarization plane holding fiber 12 passes through the inside while being held so that the plane of polarization does not rotate, and most of the light is emitted from the emission end. The emitted light forms interference fringes 50 by passing through the birefringent plate 13a and the polarizing plate 13b. The formed interference fringes 50 are projected onto an object plane (not shown) by the projection lens 14.

In general, the longer of the two wavelengths, the phase change with respect to the disturbance is more gradual, and it is easier to grasp the phase change.
However, according to the compensation for fringe scanning positions 1-4 and 1-4 ′ of the fourth embodiment, the second laser light source 23 that emits light having a wavelength λ2 longer than the light having the wavelength λ1 emitted from the laser light source 11. And the second optical multiplexer / demultiplexer 24 disposed between the laser light source 11 and the second laser light source 23 and the optical multiplexer / demultiplexer 15. Exits, passes through the second optical multiplexer / demultiplexer 24, optical multiplexer / demultiplexer 15, and phase shifter 18 ′, enters the polarization plane holding fiber 12, and exits from the polarization plane holding fiber 12 without exiting. The interference fringes 51 formed using the return light having the wavelength λ2 longer than the light having the wavelength λ1 reflected by the phase shifter 18 ′ and the optical multiplexer / demultiplexer 15 can be detected. As a result, the shift amount from the reference position of the phase of the interference fringe 51 formed using the return light having the wavelength λ2 longer than the light having the wavelength λ1 can be grasped more accurately. Then, by adjusting the phase shift amount via the phase shifter 18 ′ based on the phase shift amount from the reference position of the phase of the interference fringe 51 formed using the return light having the wavelength λ2, the projection interference fringe is adjusted. It becomes easy to accurately fix the phase of the interference fringes projected onto the object plane through the forming means at a desired position.
Other functions and effects are substantially the same as the fringe scanning position compensation structures 1-3 and 1-3 ′ of the third embodiment shown in FIGS. 3 (a) and 3 (b).

Fifth Embodiment FIG. 5 is an explanatory diagram showing a schematic configuration of a fringe scanning position compensation structure according to a fifth embodiment of the present invention. In addition, about the structure similar to 3rd Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.
In addition to the configuration of FIG. 3A, the fringe scanning position compensation structure 1-5 of the fifth embodiment further includes a second laser light source 23 and a second optical multiplexing / demultiplexing unit. , An optical multiplexer / demultiplexer 24 ', a second phase shifter 25, and a feedback controller 19 "'.
The second laser light source 23 is configured to emit light having a longer wavelength than the light having the wavelength emitted by the laser light source 11.
The second optical multiplexer / demultiplexer 24 ′ is disposed between the second laser light source 23 and the monitoring interference fringe forming means 16 (the birefringent plate 16 a in the same) and the optical multiplexer / demultiplexer 15. Yes. The second laser light source 23 and the monitoring interference fringe forming means 16 (in the birefringent plate 16a) are optically connected to different ends on the same side of the second optical multiplexer / demultiplexer 24 ', respectively. It is connected to the.
The second phase shifter 25 is disposed between the laser light source 11 and the optical multiplexer / demultiplexer 15. The second phase shifter 25 is used to scan the object plane by shifting the phase of the interference fringes projected onto the object plane, for example, by 90 degrees.
The feedback controller 19 ″ ′ emits from the second laser light source 23, passes through the second optical multiplexer / demultiplexer 24 ′, the optical multiplexer / demultiplexer 15, and the phase shifter 18 ′, and passes through the polarization plane holding fiber 12. Is incident on the polarization-maintaining fiber 12 and is reflected by the exit end face, passes through the phase shifter 18 ′, the optical multiplexer / demultiplexer 15, and the second optical multiplexer / demultiplexer 24 ′, and is monitored. By using the phase information of the interference fringe 51 formed by the interference fringe forming means 16 and detected by the interference fringe detecting element 17, the phase of the interference fringe 50 formed by the projection interference fringe forming means 13 is detected. The amount of deviation from the reference position is calculated, and the drive amount of the phase shifter 18 ′ is controlled based on the calculated amount of deviation.
Other configurations are substantially the same as the fringe scanning position compensation structure 1-3 of the third embodiment shown in FIG.

In the fringe scanning position compensation structure 1-5 of the fifth embodiment configured as described above, the second laser light source 23 is turned on when grasping the phase change of the interference fringe 50 projected onto the object plane. Then, the laser light source 11 is turned off.
The light emitted from the second laser light source 23 enters the polarization plane holding fiber 12 through the second optical multiplexer / demultiplexer 24 ′, the optical multiplexer / demultiplexer 15, and the phase shifter 18 ′. Of the light that is incident on the polarization-maintaining fiber 12 and passes through the interior and reaches the output end while being held so that the polarization plane is not rotated, a small amount of light is transmitted from the output end of the polarization-maintaining fiber 12 to the birefringent plate 13a. Reflected at the exit end face without exiting toward.
The return light reflected by the exit end face of the polarization-maintaining fiber 12 follows the optical path in the opposite direction, exits from the end face on the phase shifter 18 'side, and enters the optical multiplexer / demultiplexer 15 through the phase shifter 18'. Of the return light incident on the optical multiplexer / demultiplexer 15, the return light emitted from the end on the second optical multiplexer / demultiplexer 24 ′ side is the second optical multiplexer / demultiplexer 24 ′, fiber 22, the interference fringes 51 are formed through the birefringent plate 16a and the polarizing plate 16b. The formed interference fringe 51 is detected by the interference fringe detection element 17 and displayed on a display device (not shown).
The feedback controller 19 ″ ′ uses the phase information of the interference fringe 51 detected by the interference fringe detecting element 17 to shift the phase of the interference fringe 50 formed by the projection interference fringe forming unit 13 from the reference position. And the driving amount of the phase shifter 18 ′ is controlled based on the calculated shift amount, whereby the phase position shift when the interference fringe 50 is projected onto the object plane is corrected in real time.

When the interference fringe 50 is projected onto the object surface, the second laser light source 23 is turned off and the laser light source 11 is turned on.
The light emitted from the laser light source 11 enters the polarization plane holding fiber 12 through the second phase shifter 25, the optical multiplexer / demultiplexer 24, the optical multiplexer / demultiplexer 15, and the phase shifter 18 '. The light incident on the polarization plane holding fiber 12 passes through the inside while being held so that the plane of polarization does not rotate, and most of the light is emitted from the emission end. The emitted light forms interference fringes 50 by passing through the birefringent plate 13a and the polarizing plate 13b. The formed interference fringes 50 are projected onto an object plane (not shown) by the projection lens 14.

In the present invention, the phase shifter is used for correcting the phase shift of the phase of the interference fringes projected on the object plane. As described above, the phase shifter is also used to scan the object plane by shifting the phase of the interference fringes projected onto the object plane by 90 degrees, for example.
By the way, when one phase shifter is configured to serve both as a correction of the phase shift of the phase of the interference fringe projected on the object plane and a phase shift for scanning the object plane, Each time the phase is shifted, in order to correct the positional deviation of the phase of the interference fringes projected on the object plane at that time, it is necessary to finely adjust the driving amount of the phase shifter, and the operation becomes complicated.
However, according to the fringe scanning position compensation structure 1-5 of the fifth embodiment, in addition to the phase shifter 18 ′, the second phase shifter 25 is provided, and the interference fringe 50 projected onto the object plane by the phase shifter 18 ′. The phase shift for scanning the object plane by the second phase shifter 25 is performed independently of the correction of the phase shift of the interference fringe 50 by the phase shifter 18 ′. Therefore, fine adjustment of the driving amount of the phase shifter 25 for shifting the phase for scanning the object surface is not necessary, and the operation becomes easy.

Further, according to the fringe scanning position compensation 1-5 of the fifth embodiment, the second laser light source 23 that emits light having a wavelength λ2 longer than the light having the wavelength λ1 emitted from the laser light source 11; Since the second optical multiplexer / demultiplexer 24 ′ is disposed between the laser light source 23 and the interference fringe forming means 16 for monitoring (the birefringent plate 16a) and the optical multiplexer / demultiplexer 15, The light is emitted from the second laser light source 23, passes through the second optical multiplexer / demultiplexer 24 ′, the optical multiplexer / demultiplexer 15, and the phase shifter 18 ′, enters the polarization plane holding fiber 12, and is polarized plane holding fiber. 12 is reflected at the exit end face without being emitted from 12, and returned through the phase shifter 18 ', the optical multiplexer / demultiplexer 15, and the second optical multiplexer / demultiplexer 24', and the return of the wavelength λ2 longer than the light of wavelength λ1. The interference fringe 51 formed using light can be detected.
However, in general, the longer of the two wavelengths, the phase change with respect to the disturbance is more gradual, and it is easier to grasp the phase change.
As a result, the shift amount from the reference position of the phase of the interference fringe 51 formed using the return light having the wavelength λ2 longer than the light having the wavelength λ1 can be grasped more accurately. Then, by adjusting the phase shift amount via the phase shifter 18 ′ based on the phase shift amount from the reference position of the phase of the interference fringe 51 formed using the return light having the wavelength λ2, the projection interference fringe is adjusted. It becomes easy to accurately fix the phase of the interference fringes projected onto the object plane through the forming means at a desired position.
Other functions and effects are substantially the same as those of the fringe scanning position compensation structure 1-3 ′ of the third embodiment shown in FIG.

Modified Example of Fourth Embodiment and Fifth Embodiment FIG. 6 is an explanatory view showing a schematic configuration of a fringe scanning position compensation structure according to a modified example of the fourth embodiment and the fifth embodiment. FIG. The figure which shows the modification of embodiment, (b) is a figure which shows the modification of 5th Embodiment. In addition, about the structure similar to 4th Embodiment or 5th Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.
The fringe scanning position compensation structure 1-4 ″ of the modification of the fourth embodiment shown in FIG. 6A is the polarization plane maintaining in the fringe scanning position compensation structure 1-4 ′ shown in FIG. 4B. A wavelength selective film 40 is attached to the emission end face of the fiber 12.
The wavelength selective film 40 has a transmission / reflection characteristic with high reflectivity with respect to the wavelength λ 2 of the light emitted from the second laser light source 23.
The wavelength-selective film 40 is not transparent to the wavelength λ2 of the light emitted from the second laser light source 23, and has a high transmittance for the wavelength λ1 of the light emitted from the first laser light source 11. It preferably has reflective properties.
The other configuration is substantially the same as the fringe scanning position compensation structure 1-4 ′ of the fourth embodiment shown in FIG. 4B.

6B, the fringe scanning position compensation structure 1-5 ′ according to the modification of the fifth embodiment is emitted from the polarization-maintaining fiber 12 in the fringe scanning position compensation structure 1-5 shown in FIG. A wavelength selective film 40 is attached to the end face.
The wavelength selective film 40 has a transmission / reflection characteristic with high reflectivity with respect to the wavelength λ 2 of the light emitted from the second laser light source 23.
The wavelength-selective film 40 is not transparent to the wavelength λ2 of the light emitted from the second laser light source 23, and has a high transmittance for the wavelength λ1 of the light emitted from the first laser light source 11. It preferably has reflective properties.
Other configurations are substantially the same as the fringe scanning position compensation structure 1-5 of the fifth embodiment shown in FIG.

  According to the fringe scanning position compensation structures 1-4 ″ and 1-5 ′ of the modification of the fourth embodiment and the fifth embodiment thus configured, the second end surface of the polarization-maintaining fiber 12 is Since the wavelength-selective film 40 having transmission / reflection characteristics with high reflectivity with respect to the wavelength of light emitted from the laser light source 23 is attached, the amount of return light can be increased, and return light information detecting means (here) Then, the information of the return light (here, the phase information of the interference fringe 51) obtained via the monitor interference fringe forming means 16 and the interference fringe detection element 17) can be grasped more clearly, and as a result, for projection. The amount of deviation from the reference position of the phase of the interference fringe 50 formed by the interference fringe forming means 13 can be grasped more clearly and the deviation can be corrected more accurately.

In addition, in the fringe scanning position compensation structures 1-4 ″ and 1-5 ′ of the modification examples of the fourth embodiment and the fifth embodiment, the wavelength selective film 40 is further emitted from the second laser light source 23. If the first laser light source 11 and the second laser light source 11 are configured so as not to transmit light with respect to the wavelength λ 2, and to have transmission / reflection characteristics with high transmittance with respect to the wavelength λ 1 of light emitted from the first laser light source 11. The projection of the interference fringe 50 onto the object surface and the return light information detection means (here, the formation of the interference fringe for monitoring) in a state where both the light sources are turned on without switching the ON / OFF of the laser light source 23 At the same time, the phase change of the interference fringe 50 projected onto the object plane is grasped based on the information of the return light (here, the phase information of the interference fringe 51) obtained via the means 16 and the interference fringe detection element 17). As a result Feedback controller 19 ", 19"', the phase shifter 18' the displacement amount of understanding and correction of deviation from the phase reference position of the interference fringes 50 via can be performed in real time.
Other operational effects include the fringe operation position compensation structure 1-4 ′ of the fourth embodiment shown in FIG. 4B and the fringe operation position compensation structure 1-5 of the fifth embodiment shown in FIG. It is almost the same.

Sixth Embodiment FIG. 7 is an explanatory view showing a schematic configuration of a fringe scanning position compensation structure according to a sixth embodiment of the present invention. In addition, about the structure similar to 3rd Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.
In the fringe scanning position compensation structure 1-6 of the sixth embodiment, the return light information detection means is constituted by a light detection device 26 including a polarization beam splitter 26a and light detectors 26b and 26c.
The polarization beam splitter 26 a is disposed on the optical path of the return light that has passed through the optical multiplexer / demultiplexer 15 and the fiber 22.
The photodetectors 26b and 26c are disposed on the respective optical paths divided by the polarization beam splitter 26a. The photodetectors 26b and 26c detect the intensity of each polarized light split by the polarization beam splitter 26a.
The fringe scanning position compensation structure 1-6 of the sixth embodiment includes a feedback controller 19 "" and a display device 27.
The feedback controller 19 "" uses the intensity information of the two polarizations detected by the two photodetectors 26b and 26c to shift the phase of the interference fringe 50 formed by the interference fringe forming means 13 from the reference position. The amount is calculated, and the drive amount of the phase shifter 18 ′ is controlled based on the calculated shift amount.
The display device 27 includes a display screen that displays the intensity of each polarization detected by the two photodetectors 26b and 26c on, for example, two-dimensional coordinates.
Other configurations are substantially the same as the fringe scanning position compensation structure 1-3 of the third embodiment shown in FIG.

In the fringe scanning position compensation structure 1-6 of the sixth embodiment configured as described above, the return light reflected by the exit end face of the polarization-maintaining fiber 12 follows the optical path in the opposite direction, and is on the phase shifter 18 ′ side. The light is emitted from the end face and enters the optical multiplexer / demultiplexer 15 through the phase shifter 18 ′. Of the return light incident on the optical multiplexer / demultiplexer 15, the return light emitted from the end on the birefringent plate 16 a side enters the polarization beam splitter 26 a via the fiber 22 and is divided into two polarized lights. . The respective polarized lights divided by the polarization beam splitter 26a are detected by the photodetectors 26b and 26c. Then, the respective polarization intensities detected by the two photodetectors 26 b and 26 c are displayed on the two-dimensional coordinates on the display screen of the display device 27.
The feedback controller 19 "" uses the intensity information of the two polarizations detected by the two photodetectors 26b and 26c to shift the phase of the interference fringe 50 formed by the interference fringe forming means 13 from the reference position. The amount is calculated, and the drive amount of the phase shifter 18 ′ is controlled based on the calculated shift amount. Thereby, the positional deviation of the phase when the interference fringe 50 is projected onto the object plane is corrected in real time.
The other operations are substantially the same as the fringe scanning position compensation structure 1-3 of the third embodiment shown in FIG.

  According to the fringe scanning position compensation 1-6 of the sixth embodiment, substantially the same effect as the fringe scanning position compensation structure 1-3 'of the third embodiment shown in FIG.

Seventh Embodiment FIG. 8 is an explanatory diagram showing a schematic configuration of a fringe scanning position compensation structure according to a seventh embodiment of the present invention. In addition, about the structure similar to 3rd Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.
The fringe scanning position compensation structure 1-7 according to the seventh embodiment includes a second configuration that is arranged between the laser light source 11 and the optical multiplexer / demultiplexer 15 in addition to the configuration of FIG. The phase shifter 25 is provided.
In the fringe scanning position compensation structure 1-7 according to the seventh embodiment, the return light detecting means includes a fiber 28 as a first optical transmission fiber, a fiber 22 as a second optical transmission fiber, and optical path synthesis. The interferometer includes a member 29 and an interference fringe detector 30.
The fiber 28 is one of the two ends from which the light emitted from the laser light source 11 and incident on the optical multiplexer / demultiplexer 15 through the second phase shifter 25 is branched and emitted by the optical multiplexer / demultiplexer 15. The emitted light is connected to the end where it does not enter the phase shifter 18 ′.
The fiber 22 is emitted from the laser light source 11, passes through the second phase shifter 25, the optical multiplexer / demultiplexer 15, and the phase shifter 18 ′, enters the polarization plane holding fiber 12, and exits from the polarization plane holding fiber 12. The return light reflected by the emission end face and incident on the optical multiplexer / demultiplexer 15 via the phase shifter 18 'is branched out by the optical multiplexer / demultiplexer 15 and emitted from the two ends. The return light is connected to the end where it does not enter the second phase shifter 25.
The optical path combining member 29 is composed of a beam splitter disposed so as to combine the optical path of the light passing through the fiber 28 and the optical path of the returning light passing through the fiber 22.
The interference fringe detector 30 is arranged on the optical path synthesized by the optical path synthesis member 29 and detects an interference fringe formed using two lights passing through the synthesized optical path.
Further, the fringe scanning position compensation structure 1-7 of the seventh embodiment has a feedback controller 19 ""'.
The feedback controller 19 ″ ″ ′ uses the interference fringe phase information detected by the interference fringe detector 30 to shift the phase of the interference fringe 50 formed by the projection interference fringe forming means 13 from the reference position. And the drive amount of the phase shifter 18 ′ is controlled based on the calculated shift amount.
Other configurations are substantially the same as the fringe scanning position compensation structure 1-3 of the third embodiment shown in FIG.

  In the fringe scanning position compensation structure 1-7 of the seventh embodiment configured as described above, the light emitted from the laser light source 11 is emitted from the second phase shifter 25, the optical multiplexer / demultiplexer 15, and the phase shifter 18 '. Then, the light enters the polarization-maintaining fiber 12. The light incident on the polarization plane holding fiber 12 passes through the inside while being held so that the plane of polarization does not rotate, and most of the light is emitted from the emission end. The emitted light forms interference fringes 50 by passing through the birefringent plate 13a and the polarizing plate 13b. The formed interference fringes 50 are projected onto an object plane (not shown) by the projection lens 14.

Of the light that is incident on the polarization-maintaining fiber 12 and passes through the interior and reaches the output end while being held so that the polarization plane is not rotated, a small amount of light is transmitted from the output end of the polarization-maintaining fiber 12 to the birefringent plate 13a. Reflected at the exit end face without exiting toward. The return light reflected by the exit end face of the polarization-maintaining fiber 12 follows the optical path in the opposite direction, exits from the end face on the phase shifter 18 'side, and enters the optical multiplexer / demultiplexer 15 through the phase shifter 18'.
The return light incident on the optical multiplexer / demultiplexer 15 is branched into two optical paths. Then, the return light emitted from the end portion that does not enter the second phase shifter 25 enters the optical path combining member 29 through the fiber 22.
In addition, out of the light emitted from the laser light source 11 and incident on the optical multiplexer / demultiplexer 15 through the second phase shifter 25, the light is branched by the optical multiplexer / demultiplexer 15, and is then transmitted to the phase shifter 18 '. The light emitted from the non-incident end enters the optical path combining member 29 through the fiber 28.
The light that has entered the optical path combining member 29 through the fiber 28 and the return light that has entered the optical path combining member 29 through the fiber 22 are combined by the optical path combining member 29 to form interference fringes. The formed interference fringes are detected by the interference fringe detector 30 and displayed on a display device (not shown).
The feedback controller 19 ″ ″ ′ uses the interference fringe phase information detected by the interference fringe detector 30 to shift the phase of the interference fringe 50 formed by the projection interference fringe forming means 13 from the reference position. And the driving amount of the phase shifter 18 ′ is controlled based on the calculated shift amount. Thereby, the positional deviation of the phase when the interference fringe 50 is projected onto the object plane is corrected in real time.

According to the fringe scanning position compensation structure 1-7 of the seventh embodiment, in addition to the phase shifter 18 ′, the second phase shifter 25 is provided, and the phase of the interference fringe 50 projected onto the object plane by the phase shifter 18 ′. The phase shift for scanning the object plane by the second phase shifter 25 is performed independently from the correction of the phase shift of the interference fringe 50 by the phase shifter 18 ′. As a result, fine adjustment of the driving amount of the phase shifter 25 for shifting the phase for scanning the object surface is unnecessary, and the operation becomes easy.
Other functions and effects are substantially the same as those of the fringe scanning position compensation structure 1-3 ′ of the third embodiment shown in FIG.

Eighth Embodiment FIG. 9 is an explanatory diagram showing a schematic configuration of a fringe scanning position compensation structure according to an eighth embodiment of the present invention. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected to a structural member and detailed description is abbreviate | omitted.
In the eighth embodiment, the fringe scanning position compensation method 1-8 includes a polarizing plate 31, a first wave plate 32, an optical multiplexing / combining device disposed between the laser light source 11 and the polarization-maintaining fiber 12. Demultiplexing means 34 and a second wave plate 33 are provided.
The first wave plate 32 and the second wave plate 33 are each composed of a λ / 4 plate that is rotatably provided.
The optical multiplexing / demultiplexing means 34 includes a first beam splitter 34a, a second beam splitter 34b, a mirror 34c, and a third beam splitter 34d.
The first beam splitter 34a emits from the laser light source 11, and separates the light that has passed through the polarizing plate 31 and the first wave plate 32 into light that passes through two-way optical paths.
The second beam splitter 34 b emits from the laser light source 11, passes through the polarizing plate 31, the first wave plate 32, the first beam splitter 34 a, the second beam splitter 34 b, and the second wave plate 33, and has a polarization plane. The light that enters the holding fiber 12, is reflected by the emission end face without being emitted from the polarization plane holding fiber 12, and the return light that has passed through the second wave plate 33 is separated into light that passes through two-way optical paths.
The mirror 34c deflects the return light reflected by the second beam splitter 34b.
The third beam splitter 34d combines the optical path of the return light deflected by the mirror 34c and the optical path of the light reflected from the first beam splitter 34a.

Further, the fringe scanning position compensation method 1-8 of the eighth embodiment further includes an interference fringe detector 30 'as a return light detection means and a feedback controller 19 """.
The interference fringe detector 30 ′ is disposed on the optical path synthesized by the third beam splitter 34d, and passes through the synthesized optical path. The two lights (the return light deflected by the mirror 34c and the first beam splitter). The interference fringes formed using the light reflected by 34a) are detected.
The feedback controller 19 """uses the interference fringe phase information detected by the interference fringe detector 30 'to shift the phase of the interference fringe 50 formed by the projection interference fringe forming means 13 from the reference position. The amount is calculated, and the rotation direction and the rotation amount of the second wave plate 33 are controlled based on the calculated shift amount.

  In the fringe scanning position compensation structure 1-8 of the eighth embodiment configured as described above, the light emitted from the laser light source 11 passes through the polarizing plate 31 and the first wave plate 32, and then passes through the first beam splitter 34a. Is incident on. Of the light incident on the first beam splitter 34 a, the light transmitted through the first beam splitter 34 a is incident on the polarization plane holding fiber 12 through the second beam splitter 34 b and the second wavelength plate 33. The light incident on the polarization plane holding fiber 12 passes through the inside while being held so that the plane of polarization does not rotate, and most of the light is emitted from the emission end. The emitted light forms interference fringes 50 by passing through the birefringent plate 13a and the polarizing plate 13b. The formed interference fringes 50 are projected onto an object plane (not shown) by the projection lens 14.

Of the light that is incident on the polarization-maintaining fiber 12 and passes through the interior and reaches the output end while being held so that the polarization plane is not rotated, a small amount of light is transmitted from the output end of the polarization-maintaining fiber 12 to the birefringent plate 13a. Reflected at the exit end face without exiting toward.
The return light reflected by the exit end face of the polarization-maintaining fiber 12 follows the optical path in the opposite direction, exits from the end face on the second wave plate 33 side, passes through the second wave plate 33, and enters the second beam splitter 34b. Incident. Of the return light incident on the second beam splitter 34b, the return light reflected on the second beam splitter 34b is deflected by the mirror 34c and incident on the third beam splitter 34d.
Of the light emitted from the laser light source 11 and incident on the first beam splitter 34a through the polarizing plate 31 and the first wave plate 32, the light reflected by the first beam splitter 34a is the third light. The light enters the beam splitter 34d.
The light reflected from the first beam splitter 34a and the return light deflected by the mirror 34c are combined in the optical path by the third beam splitter 34d to form interference fringes. The formed interference fringes are detected by the interference fringe detector 30 ′ and displayed on a display device (not shown).
The feedback controller 19 """uses the interference fringe phase information detected by the interference fringe detector 30 'to shift the phase of the interference fringe 50 formed by the projection interference fringe forming means 13 from the reference position. The amount of rotation is calculated, and the rotation direction and amount of rotation of the second wave plate 33 are controlled based on the calculated amount of deviation, whereby the phase displacement when the interference fringe 50 is projected onto the object plane is real-time. It is corrected.

According to the fringe scanning position compensation structure 1-8 of the eighth embodiment, the first wave plate 32 and the second wave plate 33 are provided, and the interference wave pattern 50 projected onto the object plane by the second wave plate 33 is provided. Phase shift correction is performed, and the phase shift for scanning the object plane by the first wave plate 32 is independent of the phase shift correction of the interference fringes 50 by the second wave plate 33. Since it can be performed, fine adjustment of the driving amount of the first wavelength plate 32 for shifting the phase for scanning the object surface is not necessary, and the operation becomes easy.
Other functions and effects are substantially the same as those of the fringe scanning position compensation structure 1-3 ′ of the third embodiment shown in FIG.

  As mentioned above, although embodiment of this invention and its modification were demonstrated, this invention is not limited to a structure as described in each embodiment and its modification, In the implementation stage, the summary of invention is changed. The constituent elements can be modified and embodied within a range not to be performed. In addition, various inventions can be derived by appropriately combining a plurality of constituent elements described in each embodiment or its modification. For example, some constituent elements may be deleted from all the constituent elements described in each embodiment or its modification, or the constituent elements described in different embodiments or its modifications may be appropriately combined. Thus, various modifications and applications are possible without departing from the scope of the invention.

  INDUSTRIAL APPLICABILITY The fringe scanning position compensation structure and the endoscope apparatus including the same according to the present invention are useful in a field where measurement is required by projecting interference fringes onto an object using an endoscope.

1-1, 1-2, 1-2 ′, 1-3, 1-3 ′, 1-4, 1-4 ′, 1-4 ″, 1-5, 1-5 ′, 1-6, 1 -7, 1-8 Compensation structure for fringe scanning position 11 Laser light source 12 Polarization plane maintaining fiber 13 Interference fringe forming means 13a Birefringence plate 13b Polarizing plate 14 Projection lens 15 Optical multiplexer / demultiplexer 16 Formation of interference fringes for monitoring Means 16a Birefringent element 16b Polarizing plate 17 Interference fringe detecting element 18, 18 'Phase shifters 19, 19', 19 ", 19"', 19 "", 19 ""', 19 """Feedback controllers 21, 22 , 28 Fiber 23 Second laser light source 24, 24 'Second optical multiplexer / demultiplexer 25 Second phase shifter 26 Photodetector 26a Polarization beam splitter 26b, 26c Photodetector 27 Display device 29 Optical path combining member 30 , 30 'interference fringe detector 31 polarizing plate 32 first wave plate 33 Wave plate 34 optical multiplexing-demultiplexing means 34a of the two first beam splitter 34b second beam splitter 34c mirror 34d third beam splitter 40 wavelength-selective membrane 50 projecting fringe 51 for monitoring the interference pattern

Claims (26)

A laser light source; a polarization plane holding fiber that transmits light from the laser light source; and a projection interference fringe forming unit that forms an interference fringe using the light emitted from the laser light source and passed through the polarization plane holding fiber. In the endoscope for projecting the interference fringes formed by the projection interference fringe forming means on the object plane,
Optical multiplexing / demultiplexing means disposed between the laser light source and the polarization-maintaining fiber;
The light is emitted from the laser light source, is incident on the polarization plane holding fiber, is reflected by a predetermined optical surface arranged on the optical path to the incident surface of the projection interference fringe forming unit, and the optical multiplexing / demultiplexing unit is Return light information detecting means for detecting information of the return light that has passed;
A fringe scanning position change compensation structure characterized by comprising:   The fringe scanning position change compensation structure according to claim 1, further comprising a phase shifter disposed between the laser light source and the polarization-maintaining fiber.   Further, using the return light information detected by the return light information detection means, the amount of deviation from the reference position of the phase of the interference fringe formed by the projection interference fringe formation means is calculated, and the calculated deviation amount The fringe scanning position change compensation structure according to claim 2, further comprising: a feedback controller that controls a driving amount of the phase shifter based on the phase shifter. The return light information detecting means is
An interference fringe forming means for monitoring that forms an interference fringe using the return light;
An interference fringe detecting element for detecting the interference fringes formed by the monitor interference fringe forming means;
The fringe scanning position change compensation structure according to claim 1, wherein the fringe scanning position change compensation structure comprises:   Furthermore, using the phase information of the interference fringes detected by the interference fringe detection element, the amount of deviation from the reference position of the phase of the interference fringes formed by the interference fringe forming means for projection is calculated, and the calculated amount of deviation 5. The fringe scanning position change compensation structure according to claim 4, further comprising a feedback controller configured to control a driving amount of the phase shifter based on the phase shifter.   6. The fringe scanning position change compensation structure according to claim 2, wherein the phase shifter is disposed between the laser light source and the optical multiplexing / demultiplexing means.   6. The fringe scanning position change compensation structure according to claim 2, wherein the phase shifter is disposed between the optical multiplexing / demultiplexing means and the polarization plane holding fiber. further,
A second laser light source that emits light having a longer wavelength than the light emitted by the laser light source;
8. The fringe scanning position according to claim 7, further comprising: second optical multiplexing / demultiplexing means disposed between the laser light source and the second laser light source and the optical multiplexing / demultiplexing means. Change compensation structure.   The feedback controller emits light from the second laser light source, enters the polarization plane holding fiber through the second optical multiplexing / demultiplexing means, the optical multiplexing / demultiplexing means, and the phase shifter. Interference fringes reflected by the predetermined optical surface, passed through the phase shifter, the optical multiplexing / demultiplexing means, and formed by the interference fringe forming means for monitoring and detected by the interference fringe detecting element Is used to calculate the amount of deviation from the reference position of the phase of the interference fringes formed by the projection interference fringe forming means, and to control the driving amount of the phase shifter based on the calculated amount of deviation. 9. The fringe scanning position change compensation structure according to claim 8, which is dependent on claim 5. further,
A second laser light source that emits a longer wavelength than the light emitted by the laser light source;
A second optical multiplexing / demultiplexing means disposed between the second laser light source and the monitoring interference fringe forming means and the optical multiplexing / demultiplexing means;
The fringe scanning position change compensation structure according to claim 7, further comprising a second phase shifter disposed between the laser light source and the optical multiplexing / demultiplexing unit. .   The feedback controller emits light from the second laser light source, enters the polarization plane holding fiber through the second optical multiplexing / demultiplexing means, the optical multiplexing / demultiplexing means, and the phase shifter. Is reflected by the predetermined optical surface, passes through the phase shifter, the optical multiplexing / demultiplexing means, and the second optical multiplexing / demultiplexing means, and has interference fringes formed by the monitor interference fringe forming means. Using the interference fringe phase information detected by the interference fringe detecting element, the amount of deviation from the reference position of the phase of the interference fringe formed by the projection interference fringe forming means is calculated, and based on the calculated amount of deviation 11. The fringe scanning position change compensation structure according to claim 10, which is dependent on claim 5, wherein the driving amount of the phase shifter is controlled. The return light information detecting means is
A polarizing beam splitter disposed on the optical path of the return light that has passed through the optical multiplexing / demultiplexing means;
Two photodetectors arranged on the respective optical paths divided by the polarization beam splitter for detecting the intensity of each polarization;
The fringe scanning position change compensation structure according to claim 1, comprising:   The fringe scanning position change compensation structure according to claim 12, further comprising a phase shifter disposed between the optical multiplexing / demultiplexing means and the polarization-maintaining fiber.   Further, using the intensity information of the two polarized lights detected by the two photodetectors, the amount of deviation from the reference position of the phase of the interference fringes formed by the projection interference fringe forming means is calculated and calculated. The fringe scanning position change compensation structure according to claim 13, further comprising a feedback controller that controls a drive amount of the phase shifter based on a shift amount. A phase shifter disposed between the optical multiplexing / demultiplexing unit and the polarization-maintaining fiber; and a second phase shifter disposed between the laser light source and the optical multiplexing / demultiplexing unit. Have
The return light information detecting means is
Out of the two ends where the light emitted from the laser light source and incident on the optical multiplexing / demultiplexing means via the second phase shifter is branched and emitted by the optical multiplexing / demultiplexing means A first optical transmission fiber connected to an end not incident on the phase shifter;
The laser beam is emitted from the laser light source, passes through the second phase shifter, the optical multiplexing / demultiplexing means, and the phase shifter, is incident on the polarization plane holding fiber, is reflected by the predetermined optical surface, and the phase shifter is Out of the two ends where the return light incident on the optical multiplexing / demultiplexing means is branched and emitted by the optical multiplexing / demultiplexing means, the end where the returned return light does not enter the second phase shifter A second optical transmission fiber connected to the section;
An optical path combining member that combines an optical path of light passing through the first optical transmission fiber and an optical path of return light passing through the second optical transmission fiber;
An interference fringe detector which is disposed on the optical path synthesized by the optical path synthesis member and detects an interference fringe formed using two lights passing through the synthesized optical path;
The fringe scanning position change compensation structure according to claim 1, comprising:   Further, using the phase information of the interference fringe detected by the interference fringe detector, the amount of deviation from the reference position of the phase of the interference fringe formed by the projection interference fringe forming means is calculated, and the calculated amount of deviation The fringe scanning position change compensation structure according to claim 15, further comprising: a feedback controller that controls a driving amount of the phase shifter based on the phase shifter.   The fringe scanning position change compensation structure according to claim 1, wherein the optical multiplexing / demultiplexing means includes a fiber coupler. further,
A polarizing plate and a rotatable first wave plate disposed between the laser light source and the optical multiplexing / demultiplexing means;
A rotatable second wave plate disposed between the optical multiplexing / demultiplexing means and the polarization-maintaining fiber;
The optical multiplexing / demultiplexing means is
A first beam splitter that emits light from the laser light source and passes through the polarizing plate and the first wave plate into light in two directions;
Light emitted from the laser light source, enters the polarization plane holding fiber through the polarizing plate, the first wave plate, the optical multiplexing / demultiplexing means, and the second wave plate, and is reflected by the predetermined optical surface A second beam splitter for separating the return light that has passed through the second wave plate into light in two directions;
A mirror for deflecting the return light reflected from the second beam splitter;
A third beam splitter that combines the optical path of the return light deflected by the mirror and the optical path of the light reflected from the first beam splitter;
Consists of
The return light information detecting means is
2. An interference fringe detector that is disposed on an optical path synthesized by the third beam splitter and detects an interference fringe formed by using two lights passing through the synthesized optical path. 2. The fringe scanning position change compensation structure according to 1.   Further, using the phase information of the interference fringe detected by the interference fringe detector, the amount of deviation from the reference position of the phase of the interference fringe formed by the projection interference fringe forming means is calculated, and the calculated amount of deviation 19. The fringe scanning position change compensation structure according to claim 18, further comprising: a feedback controller that controls a rotation direction and an amount of rotation of the second wave plate based on the above.   The said predetermined optical surface is equipped with the wavelength-selective film | membrane which has a transmission / reflection characteristic with a high reflectance with respect to the wavelength of the light radiate | emitted from the said 2nd laser light source, The Claims 8-11 characterized by the above-mentioned. 18. The fringe scanning position change compensation structure according to claim 17, which is dependent on any one of items 8 to 11.   The wavelength selective film further has transmission / reflection characteristics that are not transmissive to the wavelength of the light emitted from the second laser light source and have high transmittance for the wavelength of the light emitted from the first laser light source. The fringe scanning position change compensation structure according to claim 20.   The fringe scanning position change compensation structure according to any one of claims 1 to 21, wherein the predetermined optical surface is an output end surface of the polarization plane holding fiber.   The fringe scanning position change compensation structure according to any one of claims 1 to 21, wherein the predetermined optical surface is an incident surface of the projection interference fringe forming unit.   The predetermined optical surface is an incident surface of an optical member disposed between an output end surface of the polarization plane holding fiber and an incident surface of the projection interference fringe forming unit. A change compensation structure for a fringe scanning position according to any one of the above.   The predetermined optical surface is an output surface of an optical member disposed between an output end surface of the polarization plane holding fiber and an incident surface of the projection interference fringe forming unit. A change compensation structure for a fringe scanning position according to any one of the above.   An endoscope apparatus comprising the fringe scanning position change compensation structure according to any one of claims 1 to 25.

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