JPH04118618A - Optical scanner - Google Patents

Abstract

PURPOSE:To obtain information in a sample at a high speed in a short time by providing a rotatable mirror which reflects a light beam and a 1st and a 2nd reflection part which are arranged annularly. CONSTITUTION:The sample 6 is arranged at the center position of the 1st and 2nd reflection parts 2 and 3. Then when a light emitting means 5 emits a light beam 5a to the mirror, the light beam 5a is reflected by the mirror 12 and 1st reflection part 2 to reach the sample 6. The light beam passed through the sample 6 is reflected by the 2nd reflection art 3 and reaches a photodetecting means 4. The photodetecting means 4 receives the light beam which is changed according to the state of the sample 6 and measures its intensity, so the state of the sample 6 can be known from the received light beam. This measuring operation is carried on over a 360 deg. ranges while the mirror is rotated to scan the sample 6 in the direction of 360 deg.. In this case, a large-sized member needs not to be rotated and only the rotary mirror is rotated to obtain information on the sample 6 at a high speed in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical scanning device, and particularly to an optical scanning device that uses a light beam to obtain information inside a translucent object.

[Prior Art] A conventional optical scanning device, for example, a CT device using a laser beam, is disclosed in Japanese Patent Application Laid-Open No. 1-56411, which has a rotatable gantry (drum) in which a subject is placed in the center. It is shown. Inside the gantry, a reflecting mirror and a light-receiving section placed at a position facing the reflecting mirror with the subject in between are provided. The reflecting mirror and the light receiving section are fixed to the gantry and rotate as the gantry rotates. Laser light from an externally provided laser unit is incident on the reflecting mirror.

In the above-mentioned optical scanning device, the laser beam from the laser unit 7) is converted into a fan beam with a fan-like spread by a reflecting mirror, and is irradiated onto the object, and the transmitted light from the fan beam is received by a light receiving section arranged in an array. Obtain internal information about the subject. By performing this detection operation while rotating the gantry, it is possible to inspect the subject from 360 degrees.

[Problem to be solved by the invention]

In the conventional configuration, it is necessary to rotate the gantry, which is a large member, with high precision. For this reason, the gantry cannot be rotated at high speed, and
It takes a long time to perform the inspection from the angle direction. As a result, it takes l time from the start to the end of the test.

An object of the present invention is to provide an optical scanning device that can obtain information inside a subject at high speed and in a short time.

[Means to solve the problem]

The optical scanning device according to the present invention is a device that obtains information inside a subject using a light beam. This device includes a light emitting means, a mirror, a light receiving means, and first and second reflecting parts.

The light emitting means is a means for emitting a light beam.

The mirror is a rotatable member that is disposed on the optical axis of the light beam and reflects the light beam in a direction intersecting the optical axis. The light receiving means is a means for measuring the intensity of incident light. The first reflecting section is a member arranged in an annular shape that receives the light beam reflected by the mirror and reflects it into a plane intersecting the optical axis. The second reflecting section is a member that is arranged concentrically with the first reflecting section and in an annular shape, and receives the light beam from the first reflecting section and reflects it toward the light receiving means.

[Effect]

In the optical scanning device according to the present invention, the subject is placed at the center of the first and second reflecting sections.

Then, when the light emitting means emits a light beam towards the mirror,
The light beam is reflected by the mirror and the first reflecting section and reaches the subject. The light beam that has hit the subject is reflected by the second reflection section and reaches the light receiving means. The light receiving means receives a light beam that changes depending on the condition of the subject and measures its intensity, so it is possible to know the condition of the subject based on the received light beam.

This measurement operation can be performed 360° by rotating the mirror.
If the angles are successively scanned, the object can be scanned from 360 degrees. Here, information on the subject can be obtained at high speed and in a short time by rotating a rotating mirror without rotating a large member.

[Example] Figs. 1 and 2M show optical CT as an example of the present invention.
Show the device.

In these figures, the optical CT apparatus includes a cylindrical drum-shaped gantry 1, a pair of primary and secondary reflecting devices 2°3 arranged concentrically within the gantry 1, and a primary reflecting device 2. The gantry 1 includes a reflection/light receiving unit 4 disposed at the center of the gantry 1, and a laser unit 5 concentrically disposed at the rear of the gantry 1 (to the right in FIG. 1). In addition, reflection
The central axis of rotation of the light receiving unit 40 and the optical axis of the output light of the laser unit 5 coincide.

The gantry 1 has a hole 10 in one end wall 1a into which a subject 6 (for example, a human head) is inserted, and a hole 11 in the other end wall through which the laser beam 5a from the laser unit 5 passes. 1b. Note that the center of hole 10.11 is
It coincides with the center of gantry 1 itself.

The primary reflecting device 2 includes a mirror group 2 consisting of a large number of flat mirrors 12a arranged in an annular shape, and a mirror group 1.
The shutter group 13 includes a large number of liquid crystal shutters 13a arranged concentrically and annularly on the inner circumferential side of the liquid crystal display 2. The mirror group 12 and the shank group 13 form part of a conical surface that is inclined at an angle of 45'' with respect to its center line and has its center on the laser unit 5 side.

The liquid crystal shanks 13a of the shutter group 13 are respectively switched between an ON state and an OFF state under control from a control section to be described later. The liquid crystal shutter 13a is ON
When it is in the OFF state, it becomes a surface reflection state, and when it is in an OFF state, it becomes a translucent state. On the other hand, the secondary reflecting device 3 also includes a mirror group 14 and a shank group 15 similar to those of the primary reflecting device 2. However, in the secondary reflection device 3, the mirror group 14
The plane mirror 14a and the liquid crystal shank 15a of the shank group 15 form part of a conical surface having its center on the hole 10 side, and its inclination angle is 45 degrees.

The primary reflecting device 2 and the secondary reflecting device 3 are each arranged concentrically with the gantry 1, with the inner surfaces of the reflecting devices 2 and 3 facing each other.

The reflection/light receiving unit 4 includes a reflection/light receiving unit 20 and a reflection/light receiving unit 4.
It has a driving device 21 including a stepping motor for rotationally driving the light receiver 20.

A rotation shaft 22 of the drive device 21 is arranged concentrically with the gantry 1, and a reflector/light receiver 20 is fixed to the tip thereof. As shown in Figures 3Δ to 3C, the reflector/light receiver 20 includes a mirror 23 having an inclination of 45@ with respect to the center line of the rotation axis 22, and a light receiving section 24 disposed on the back side of the mirror 23. It has The light receiving section 24 includes a light receiving window 25 having an arcuate surface, and a light receiving window 25 in the reflection/light receiver 20.
The photomultiplier tube (photomultiplier) (not shown) is arranged to face the photomultiplier tube 5. Note that one photomultiplier tube may be provided, or a plurality of photomultiplier tubes may be provided so that each channel can receive light.

For example, the laser unit 5 has an output of several tens of mW to
Multiple types of semiconductor laser systems with different laser wavelengths of 100 mW are built-in, and wavelength selection is possible. Further, a collimating lens is provided within the laser unit 5. Note that other configurations may be adopted as the laser unit 5 as long as a pencil beam can be realized.

Furthermore, this optical CT apparatus has a control section 30 as shown in FIG. The control unit 30 includes a CPU 31, a ROM
32 and a microcomputer with RAM 33. The I10 boat 34 of the control unit 30 includes the control unit 3
a keyboard 35 for inputting commands to the 01;
A CRT 36 that displays a clear image based on the operating state and hack projection processing (described later) and a printer 37 that prints out measurement result data and the like are connected. Furthermore, the I10 port 34 has a laser unit 5, a reflection/light receiving unit 4, and a shutter group 13.15.
and other input/output sections 16 are connected. In addition,
The other input/output unit 16 also includes a drive device for a bed (not shown) for moving the subject 6 in the direction of the center line of the gantry 1.

Next, the operation of the above embodiment will be explained according to the control flowcharts shown in FIGS. 5A and 5B.

When the program starts, step S1 in FIG. 5A
, the laser unit 5 is activated and the reflector/receiver 2
Initial settings such as setting 0 to the initial position are performed.

In step S2, it is determined whether the measurement start key on the keyboard 35 has been pressed. In step S3, it is determined whether the projection start key on the keyboard 35 has been pressed. In step S4, it is determined whether the print start key has been pressed. Then, in step S5, predetermined processes other than the processes related to input keys in steps 32 to S4 are executed. When the process in step S5 is completed, the process returns to step S2.

Assuming that the operator sets the subject 6 in the gantry 1 as shown in FIG. 1 and presses the 1st constant start key on the keyboard 35, the program moves from step S2 to step S6 and proceeds to step S6 as shown in FIG. 5B. Execute the measurement subroutine. In step S7 of FIG. 5B, the laser unit 5
A command to start laser emission is issued to the target. by this,
The laser unit 5 starts emitting laser light 5a.

In step S8, the reflector/light receiver 20 of the reflector/light receiver unit 4 is set to the unit initial position. The unit here is the range in which a scanning operation is performed using one mirror 12a of the mirror group 12. And, as the unit initial position,
For example, this is the position of the mirror 23 set so that the laser beam 5a passes along the dashed line A in FIG.

In addition, FIG. 6 shows the mirror group 12.14 and the shutter group 1.
3.15 is an exploded partial view. Mirror group 12.1
4 mirrors 12a, 14a and shutter group 13.15
The black circles shown in each liquid crystal shutter 13.15a are reflection points of the laser beam 5a.

In step S9 of FIG. 5B, it is determined whether the reflector/receiver 20 has made one rotation (360° rotation). This determination is made based on the amount of rotation of the stepping motor within the drive device 21. If it has not rotated once, step SI
Move to O.

In step SIO, five liquid crystal shutters 13a and five liquid crystal shutters 15a receive the laser beam 5a reflected by the mirror 12a opposite to the mirror 23 of the reflection/receiver 20.
is in the ON state, and the other liquid crystal shutters 13a, 1
5a is turned off. As a result, the liquid crystal shutters 13a and 1'5a that are in the ON state become in a specular reflection state, and the remaining liquid crystal shutters 13a and 15a become in a transmissive state. Therefore, the laser beam 5 exiting the laser unit 5
a is refracted in the radial direction by the mirror 23 of the reflector/receiver 20, passes through the liquid crystal shutter 13a, and is reflected by the mirror 12a.
It is reflected in a direction parallel to the center line. Furthermore, the laser beam 5
The light a passes through the liquid crystal mirror 15a, is reflected by the mirror 14a, and enters the subject 6. The laser beam 5a that has passed through the subject 6 is reflected by the liquid crystal shutter 15a that is in the ON state, further reflected by the liquid crystal shank 13a that is in the ON state, and enters the light receiving section 24 of the reflector/light receiver 20.

The path of the laser beam 5a at this time is indicated by a dashed line A in FIG.

The intensity of the laser beam incident on the light receiving section 24 is determined in step 31.
1, the voltage value from the photomultiplier tube of the light receiving section 24 is inputted to the control section 30. In step S12, the measured value is stored in the RAM 33 together with the measured angle.

In step S13, the reflection/light receiving unit 4 is rotated by minute units. As a result, the mirror 23 of the reflector/receiver 20 is in a position to reflect the laser beam 5a in the direction of the dashed line B in FIG.

In step S14, one mirror 12a (that is, one
It is determined whether all measurements regarding the measured vehicle position have been completed. Here, for example, as shown in FIG.
It is designed to measure five routes of -E, and -
The program returns to step S11 until the measurement of the route indicated by the dashed dotted line E is completed, and thereafter repeats the above process. As a result, within one measurement vehicle position, the subject 6 is scanned in a fan shape by the slight rotation of the reflector/light receiver 20 (step 513). However, as is clear from FIG. 6, the liquid crystal shutter 15a of the shutter group 15 is
It is arranged in a posture that makes the path of the fan-shaped laser beam 5a parallel. Also, the liquid crystal shutter 1 of the shutter group 13
3a is arranged in a posture that focuses the path of the parallel laser beam 5a onto the light receiving section 24. Therefore, the laser light 5a that scans the subject 6 in a fan shape is detected at one point on the light receiving section 24.

When the measurement is completed for the five routes indicated by the dashed-dotted line A-H at one measurement vehicle position, the process returns from step S14 to step S8, and the reflector/light receiver 20 is set at the initial position of the next measurement unit. Then, the processes from step S8 to step S14 are repeated until it is determined in step S9 that the reflection/light receiving unit 4 has rotated once. As a result, the subject 6
Scanning is repeated in a fan-like manner at an angle of 360° with respect to the image data, and each data is stored in the RAM 33 of the control unit 30. Here, the laser beam reflected by the reflection/light receiving unit 4 is transmitted to the mirror group 12 due to the difference in the incident angle when moving one mirror 12a (plane) of the mirror group 12.
It spreads out in a fan shape from the shutter group 15 to the shutter group 15. Therefore, reflection
If the light-receiving unit 4 continues to rotate, the object 6 will be scanned over its entire circumference by the fan-shaped laser light. Since the speed of this scanning is determined by the rotational speed of the reflection/light receiving unit 4, it is possible to measure the entire circumference of the subject 6 at high speed.

If the determination in step S9 is Yes, step S1
5, and the laser emission from the laser unit 5 is stopped. The program then returns to the main routine of FIG. 5A. At this stage, data on the amount of laser light absorption obtained by fan-shaped scanning for each measurement unit is stored in the RAM 33.

Next, a tomographic image (CT image) of the subject 6 is created based on the measurement results.
If the operator wishes to obtain the desired result, the operator presses the projection start key on the keyboard 35. As a result, the program moves from step S3 to step S16, and executes the projectidine subroutine. Note that the processing here is performed based on arithmetic processing such as data preprocessing, convolution, and pack projection, as in the -C type CT packing apparatus, so a detailed explanation will be omitted. here,
The tomographic image is displayed on the CRT 36 in, for example, 16 levels of gray scale. Note that each part can also be enlarged. When the processing in step 5l-6 is completed, the program returns to the main routine.

If the operator wishes to print out the obtained data, etc., the operator presses the print start key on the keyboard 35. As a result, the program moves from step S4 to step S17.
and executes the print subroutine. The processing here is also similar to that of a normal OCT apparatus, so the explanation will be omitted. When the process in step 317 is completed, the program returns to the main routine.

In this way, according to this embodiment, the liquid crystal shutters 13a and 1 can be moved without rotating large members such as the gantry 1.
Since measurement is performed by turning on and off the sensor 5a and rotating the reflection/light receiving unit 4, fan-shaped scanning of the object 6 can be performed over the entire circumference at high speed and in a short time.

Note that instead of rotating the reflection/light receiving unit 4, the object 6
A projection image (CR image) obtained by moving a bed (not shown) on which the object is placed may be taken.

11''A FIG. 7 shows another embodiment of the invention.

In FIG. 7, this optical CT apparatus includes a cylindrical drum-shaped gantry 40, a reflection device 41 arranged concentrically within the gantry 40, a reflection/light receiving unit 42, and a rear part of the gantry 40 (right side in FIG. 7). The laser unit 43 is arranged concentrically in both directions. In addition, reflection
The central axis of rotation of the light receiving unit 42 and the laser unit 4
The optical axis of the output light of No. 3 coincides with the optical axis of the output light of No. 3.

The gantry 40 has a hole 45 into which the subject 44 is inserted in one end wall 40a, similar to that shown in the first embodiment described above.
The laser beam 43 from the laser unit 43
The other end wall 40b has a hole 46 through which the rays a pass.

As shown in FIG. 8, the reflecting device 41 includes a mirror group 4 made up of a large number of flat mirrors 47a arranged in an annular shape.
7, and a shutter group 48 composed of a large number of liquid crystal shutters 48a arranged concentrically and annularly on the inner peripheral side of the mirror group 47. The mirror group 47 and the shutter group 48 are inclined with respect to their center lines so as to form part of a conical surface. The liquid crystal shutter 48a of the shutter group 48 is controlled between the ON state and the OF state by control from the control section.
It is possible to switch between the F state and the F state. The liquid crystal shack 48a is in a surface reflection state when it is in an ON state, and is in a transmissive state when it is in an OFF state.

The reflection/light receiving unit 42 includes a reflection/light receiving device 49 and a driving device 50 including a stepping motor for rotationally driving the reflecting/light receiving device 49. The rotation shaft 51 of the drive device f50 is arranged concentrically with the gantry 40,
A reflector/light receiver 49 is fixed to its tip. Reflection/
A mirror 49a is attached to one side of the light receiver 49,
The mirror 49a is attached slightly inclined with respect to the center line of the rotating shaft 50. The inclination angle φ of the mirror 49a is
It is determined that the light from the laser unit 43 is reflected toward the mirror group 47. A light receiving section 52 is provided on the back side of the reflector/light receiver 49.

The light receiving section 52 is provided with a light receiving window and a photomultiplier tube (not shown). Further, each liquid crystal shutter 48a of the shutter group 48 is arranged in a posture such that the incident light from each plane mirror 47a of the mirror group 47 is reflected toward the reflection/light receiving unit 42 and focused on the light receiving section 52.

Note that the laser unit 43 has the same configuration as the laser unit 5 shown in the above-described first embodiment, and the description thereof will be omitted here. Further, this optical CT apparatus has a control section having the same configuration as the control section 30 of Example 10. This device is controlled by this control section.

Next, the operation will be explained.

As mentioned above, the device of this embodiment has a configuration in which one of the reflecting devices is omitted from that shown in Embodiment 1, and the operation of this embodiment is generally the same as that of Embodiment 1 described above. Therefore, detailed explanation will be omitted here. Note that during measurement, the liquid crystal shank 48a of the shutter group 48, through which the reflected light from the reflection/light receiving unit 42 enters, is turned off, and the shutter group 48a, through which the laser beam transmitted through the object 44 enters, is in the OFF state. The liquid crystal shutter 48a is turned on. As a result, the liquid crystal shutter 48a that is in the OFF state becomes a light-transmitting state, and the liquid crystal shutter 48a that is in an ON state becomes a specular reflection state.

In this case, the laser beam 4 emitted by the laser unit 43
3a is reflected by the mirror 49a of the reflector/receiver 49. The reflected light from the reflection/receiver 49 passes through the liquid crystal shutter 48a, is reflected by the mirror 47a in a direction perpendicular to the center line, and enters the subject 44. The laser beam 43a transmitted through the object 44 is transmitted to the liquid crystal shutter 4 which is in the ON state.
It is reflected by 8a and enters the light receiving section 52 of the reflection/light receiver 49. Then, the intensity of the incident laser light is measured by the light receiving section 24. Therefore, by rotating the reflection east/light receiving unit 42 by 3606 rotations, the subject 44 can be scanned in a fan shape from all directions, and a CT image can be obtained. Note that the reflected light reflected by one plane mirror 47a has a fan shape, and the locus of the incident point on the liquid crystal shutter 48a becomes a curve, causing an error, but this is within a practically acceptable range.

In this case as well, as in the first embodiment described above, the liquid crystal
Since measurements are performed by turning on and off the ivy 48a and rotating the reflection/light receiving unit 42, fan-shaped scanning can be performed over the entire circumference of the subject 44 at high speed and in a short time. Moreover, since one of the reflecting devices is omitted compared to the device of Example 1, the structure is simplified and costs can be reduced.

Implementation ■ Main FIG. 9 shows yet another embodiment of the invention.

In FIG. 9, a gantry 601 reflecting/receiving unit 63. The laser unit 64 and the laser unit 64 have the same configuration as that shown in the second embodiment described above, and detailed description thereof will be omitted here.

Inside the gantry 60 are primary and secondary reflectors 61.
．． 62 are arranged. The primary reflecting device 61 is the eighth
It has the same configuration as the mirror group 47 shown in the figure, and includes a large number of plane mirrors arranged in an annular shape. The secondary reflecting device 62 is arranged concentrically with the primary reflecting device 61, but they are not overlapped. Secondary reflector 6
2 has a plurality of curved mirrors arranged at predetermined intervals on the circumference. The curvature of each curved mirror reflects the incident light from each plane mirror of the primary reflecting device 6I.
It is formed so as to be reflected toward the light receiving unit 63 and focused on the light receiving section 67 .

In this case, the retarser beam 64a emitted from the laser unit 64 is reflected by the mirror 65a of the reflection/receiver 65 and enters the primary reflection device 61. Then, the reflected light reflected by the plane mirror of the primary reflection device 61 passes through the subject 66 and enters the secondary reflection device 62 . The reflected light reflected by the curved mirror of the secondary reflection device 62 is detected by the light receiving section 67 of the reflection/light receiving unit 63. In this embodiment as well, the entire circumference of the subject 66 is scanned while the reflection/light receiving unit 63 is rotated in the same manner as in the above-described embodiment 1.2.

In this case, as in the first and second embodiments described above, reflection and reflection can be performed without rotating large members such as the gantry 60.
Since measurement is performed by rotating the light receiving unit 63, fan-shaped scanning of the entire circumference of the subject 66 can be performed at high speed and in a short time. Moreover, unlike Embodiment 1.2, each reflecting device is constituted by only mirrors without using an expensive liquid crystal screen, so a cheaper device can be realized.

10 to 12 show still other embodiments of the present invention.

This optical CT apparatus includes a reflective bag W71 disposed within a gantry 70, a mirror 72, a light receiving section 73, and a laser unit 74. Here, laser unit 7
4 is the object 75 and the mirror 72 in the gantry 70.
It differs from each of the above-mentioned embodiments in that it is arranged between. In this way, the unit 7 is placed inside the gantry 70.
4, the entire device can be made compact. Further, compared to the devices of Examples 2 and 3, there is an advantage that the angle of incidence θ of the laser beam on the mirror 72 can be made smaller, thereby making it easier to adjust each part. Note that Fig. 10 shows the case where the incident angle θ is θ = 30°, and Fig. 11 shows the case where the incident angle θ is 30°.
FIG. 12 shows the one with θ>306.

The reflecting device 71 is a device similar to the reflecting device 41 (FIG. 8) shown in the second embodiment, and includes a mirror group 76 and a mirror group 7.
A shutter group 77 is arranged concentrically on the inner peripheral side of the shutter 6. These mirror group 76 and shutter group 77
are the mirror group 47 and shutter group 48 in FIG. 8, respectively.
It corresponds to Note that in FIGS. 10 and 11, the mirror group 76 and the shutter group 77 have different inclination angles with respect to the center line.

A drive device 78 for rotationally driving the mirror 72 is arranged on the back side of the mirror 72 (on the right side in each figure). A rotating shaft 79 of the drive device 7 is arranged concentrically with the gantry 70, and a mirror 72 is fixed to the tip thereof.

Furthermore, in the device shown in the 10th article, a light receiving section 73 is provided on the side of the mirror 720. This is because the reflected laser light reflected by the shutter group 77 enters the side of the mirror 72. In the apparatus shown in FIG. 11, a light receiving section 73 is arranged in a ring shape around a mirror 72 in a gantry 70. As shown in FIG. This is because the laser beam reflected by the shutter group 77 is incident on the reflective surface of the mirror 72, so that the laser beam reflected by the mirror 72 is detected. In the 121st M1 device, since the laser beam reflected by the shutter group 77 is incident on the back side of the mirror 72, the light receiving section 73
is provided on the back side of the mirror 72.

Next, the operation will be explained.

As mentioned above, the device of this embodiment is the device shown in Example 2 (
7), the laser unit 43 is connected to the gantry 40.
The operation of this embodiment is generally the same as that of the second embodiment described above, and detailed explanation will be omitted here. Note that during measurement, the liquid crystal shutter of the shutter group 77, on which the light reflected by the mirror 72 enters, is set to O.
The liquid crystal shutters of the shutter group 77, on which the laser light transmitted through the subject 75 is incident, are set to the FF state and enter a light-transmitting state, and are set to the ON state and enter a specular reflection state.

The laser beam emitted by the laser unit 74 is reflected by the mirror 72. This reflected laser light is transmitted to the shutter group 77.
The light passes through the liquid crystal shutter, is reflected by the mirrors of the mirror group 76 in a direction perpendicular to the center line, and enters the subject 75. The laser beam transmitted through the object 75 is turned on when the shutter group 77 is turned on.
The light is reflected by the liquid crystal shutter in the current state and enters the light receiving section 73. Then, the intensity of the incident laser beam is measured by this light receiving section 73. Further, in the same manner as in each of the above-described embodiments, the mirror 72 is rotated by the drive device 78 while the subject 75 is being rotated.
Scanning is performed over the entire circumference.

In this case as well, since the measurement is performed by rotating the mirror 72 without rotating a large member such as the gantry 70, the fan-shaped scan of the object 75 can be performed over the entire circumference at high speed and in a short time. Furthermore, unlike the above embodiments, the laser unit 74 is disposed within the gantry 70 between the subject 75 and the mirror 72, so the apparatus can be made compact. Further, since the incident angle θ of the laser beam incident on the mirror 72 from the laser unit 74 can be made small, adjustment of each part can be easily performed.

fire flame l FIG. 13 shows yet another embodiment of the invention.

In FIG. 13, Example 4 shown in FIGS. 10 to 12
The same reference numeral indicates the same or equivalent item. In the apparatus of this embodiment as well, the laser unit 74 is disposed within the gantry 70 between the subject 75 and the mirror 72, as in the apparatus of the fourth embodiment, making the apparatus more compact and making it easier to adjust each part. is planned. Furthermore, in the device of this embodiment, a reflection device 80 that reflects light reflected by the mirror 72 is different from that shown in the fourth embodiment.

This reflecting device 80 is a device similar to the reflecting device shown in Example 3 (FIG. 9), and includes a primary reflecting device 81 and a secondary reflecting device 81.
It is composed of a secondary reflection device 82. The primary reflecting device 81 corresponds to the primary reflecting device 61 in FIG. 9, and the secondary reflecting device 82 corresponds to the secondary reflecting device 62 in the same figure. Note that the light receiving section 73 is arranged in an annular shape on the side of the reflecting device 80.

Next, the operation will be explained.

In this case, as in the case of the third embodiment, the laser beam emitted from the L-the unit 74 is transmitted to the primary reflection device 8.
1, passes through the object 75 and passes through the secondary reflection device 82.
The reflected laser light from the secondary reflection device 82 is detected by the light receiving section 73 . Then, in the same manner as in each of the embodiments described above, scanning is performed over the entire circumference of the subject 75 while rotating the mirror 72.

Even in this case, there is no need to rotate a large member such as the gantry 70, and fan-shaped scanning of the entire circumference of the subject 75 can be performed at high speed and in a short time. Moreover, since the laser unit 74 is arranged inside the gantry 70, the entire apparatus can be made compact and each part can be easily adjusted. Furthermore, since the reflecting device 80 is configured only with mirrors, it is possible to realize an inexpensive device.

〔Effect of the invention〕

In the optical scanning device according to the present invention, the above-mentioned mirror and the first . Since the second reflecting section is provided, the entire circumference of the object can be measured at high speed without rotating a large member. Therefore, according to the present invention, it is possible to realize an optical scanning device that can obtain information inside a subject at high speed and in a short time.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view of an embodiment of the present invention, FIG. 2 is an exploded schematic diagram thereof, and FIGS. 3A, 3B, and 3C are front, side, and bottom views of the reflector/receiver. , FIG. 4 is a schematic block diagram of a control unit according to an embodiment of the present invention, FIGS. 5A and 5B are control flowcharts thereof, FIG. 6 is a developed partial diagram of a laser beam path, and FIG. 7 is a schematic block diagram of a control unit according to an embodiment of the present invention. FIG. 8 is a schematic vertical cross-sectional view of another embodiment of the invention, and FIG. 9 is an exploded schematic view of the reflecting device. FIGS. 10, 11, 12, and 13 are schematic vertical cross-sectional views of different embodiments. 4.42.63...Reflection/reception unit, 23°72
...Mirror, 5,43,64.78...Laser unit, 5a, 43a, 64a...Laser light, 6°44
．． 66.75...Subject, 12.14.47°61.
76.81...Mirror group, 12a, 14a. 47 a-Mirror 13,15.48.11...C+
Ivy group, 13a, 15a, 48a...liquid crystal shutter,
24.52, 67.73... Light receiving section, 62.82...
・Secondary reflector. Fig. 2b 4...Reflection/light receiving unit 5...Laser unit 5a...Laser beam 12...Mirror group 2a...Mirror 13...No^ Ivy group 3a...Liquid crystal Noteta 23 ...Mirror 24...Light receiving part 6...Subject 1 PjflsA Figure 581 Figure 7 Figure 8

Claims (1)

[Claims] (1) An optical scanning device that obtains information inside a subject using a light beam, the device comprising: a light emitting unit that emits a light beam; and a light emitting device that is arranged on the optical axis of the light beam and that extends in a direction that intersects with the optical axis. a rotatable mirror that reflects a light beam; a light receiving unit that measures the intensity of the incident light; and a ring-shaped mirror that receives the light beam reflected by the mirror and reflects the light beam into a plane intersecting the optical axis. a second reflecting section that receives a light beam from the first reflecting section and reflects it toward the light receiving means, and is arranged concentrically with the first reflecting section and in an annular shape. Device.