JPH06110003A - Optical scanning device - Google Patents

Abstract

PURPOSE:To obtain information on a body to be inspected at a high speed in a short time by providing a 1st and a 2nd reflection parts which reflect the light reflected by a rotatable mirror and are annularly arranged. CONSTITUTION:This optical scanning device is equipped with a couple of primary and secondary reflecting devices 2 and 3 which are arranged annularly and concentrically in a gantry 1, a reflection and light receiving unit 4 which is arranged at the center position of the primary reflecting device 1, and a laser unit 5. The center axis of rotation of the reflection and light receiving unit 4 is aligned with the optical axis of output light of the laser unit 5. The laser light 5a emitted by the laser unit 5 is radially refracted by the mirror of a reflector light receiving unit 20 and reflected by the mirrors 12 and 14 of the primary and secondary reflecting devices 2 and 3 to become parallel light, which is made incident on the body 6 to be inspected; and the transmitted laser beam 5a is reflected by the liquid crystal shutters 15 and 13 of the secondary and primary devices 3 and 2 and made incident on a light receiving part 24, which measures its intensity. This measuring operation is carried on covering a 360 deg. angle while the reflector light receiving unit 20 is rotated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device, and more particularly to an optical scanning device for obtaining information in a light-transmissive subject by using a light beam.

[0002]

2. Description of the Related Art As a conventional optical scanning device, for example, a CT device using laser light, Japanese Patent Application Laid-Open No. 1-56411 discloses:
It is shown to have a rotatable gantry (drum) with the subject placed in the center. In the gantry,
A reflection mirror and a light receiving unit arranged at a position facing the reflection mirror through the subject are provided. The reflecting mirror and the light receiving unit are fixed to the gantry and rotate according to the rotation of the gantry. Laser light from a laser unit provided outside is incident on the reflection mirror.

In the above-mentioned optical scanning device, a laser beam from the laser unit is made into a fan beam having a fan-shaped spread by a reflection mirror and irradiated onto a subject, and the transmitted light from there is received by a light receiving section arranged in an array. By receiving
Obtain internal information about the subject. By performing this detection operation while rotating the gantry,
The inspection can be performed from the direction of 0 °.

[0004]

SUMMARY OF THE INVENTION In the above conventional configuration,
It is necessary to rotate the gantry, which is a large member, with high accuracy. Therefore, the gantry cannot be rotated at a high speed, and it takes a long time to inspect the subject from the direction of 360 °. As a result, it takes time from the start to the end of the inspection.

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

[0006]

An optical scanning device according to the present invention is a device for obtaining information in a subject by using a light beam. This device comprises a light emitting means, a mirror, a light receiving means,
The first and second reflecting portions are provided.

The light emitting means is means for emitting a light beam. The mirror is a rotatable member that is arranged 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 means for measuring the intensity of incident light. The first reflecting portion is a member having a parabolic reflecting surface that is arranged in an annular shape and that receives the light beam reflected by the mirror and reflects it into a plane that intersects the optical axis. The second reflecting portion is a member that receives the light beam from the first reflecting portion and reflects it toward the light receiving means, and is arranged concentrically with the first reflecting portion and in an annular shape.

[0008]

In the optical scanning device according to the present invention, the subject is placed at the center positions of the first and second reflecting portions. Next, when the light emitting means emits a light beam toward the mirror, the light beam is reflected by the mirror and the first reflecting portion and reaches the subject. The light beam that has passed through the subject is reflected by the second reflecting section and reaches the light receiving means. The light receiving means receives the light beam that has changed according to the state of the subject and measures its intensity, so that the state of the subject can be known based on the received light beam.

If such a measuring operation is successively performed for the angle of 360 ° while rotating the mirror, the object can be scanned from the direction of 360 °. Here, the information of the subject can be obtained at high speed and in a short time by rotating the rotating mirror without rotating a large member.

Further, since the first reflecting portion has a parabolic reflecting surface, all the light reflected by the first reflecting portion becomes parallel light and enters the subject. As a result, the time for processing the information from the subject can be shortened, and the processing can be performed in a shorter time.

[0011]

Embodiment 1 FIGS. 1 and 2 show an optical CT apparatus as an embodiment of the present invention. In these figures, this optical CT apparatus is composed of a cylindrical drum-shaped gantry 1, a pair of primary and secondary reflecting devices 2 and 3 concentrically arranged in the gantry 1, and a primary reflecting device. The reflection / light receiving unit 4 is arranged at the center position of the laser beam 2, and the laser unit 5 is arranged concentrically behind the gantry 1 (on the right side of FIG. 1). The central axis of rotation of the reflection / light receiving unit 4 and the optical axis of the output light of the laser unit 5 coincide with each other.

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 the other hole 11 through which the laser beam 5a from the laser unit 5 passes. It has on the end wall 1b. The holes 10, 1
The center of 1 corresponds to the center of the gantry 1 itself.

The primary reflection device 2 includes a mirror group 12 composed of a large number of plane mirrors 12a arranged in an annular shape.
And a shutter group 13 including a large number of liquid crystal shutters 13a arranged concentrically and annularly on the inner peripheral side of the mirror group 12. The mirror group 12 and the shutter group 13 form a part of a conical surface that is inclined at an angle of 45 ° with respect to its center line and has a vertex on the laser unit 5 side. The liquid crystal shutters 13a of the shutter group 13 are
The ON state and the OFF state are controlled by the control unit described later.
The states can be switched between. LCD shutter 1
3a is in a surface reflection state when it is in an ON state, and is in a translucent state when it is in an OFF state.

On the other hand, the secondary reflecting device 3 has a mirror group 14 composed of a large number of parabolic mirrors 14a arranged in an annular shape. Each parabolic mirror 14a is curved inward (see FIG. 3) and has a reflecting surface 16 inside. The reflecting surface 16 is formed in a parabolic shape in a cross section in the AA direction, and the focus of this parabolic surface is on the mirror 23 of the reflection receiver 20 via the corresponding plane mirrors 12a of the mirror group 12. It is located in. Thereby, the incident light from each plane mirror 12a becomes all parallel light after being reflected by each parabolic mirror 14a. On the inner circumference side of the mirror group 14,
Many liquid crystal shutters 15a arranged concentrically and annularly
A shutter group 15 is provided. The mirror group 14 and the shutter group 15 constitute the secondary reflecting device 3. Further, in the secondary reflecting device 3,
Parabolic mirror 14a of mirror group 14 and shutter group 15
The liquid crystal shutter 15a is arranged on a conical surface having an apex on the hole 10 side, and its inclination angle is 45 °.
The primary reflection device 2 and the secondary reflection device 3 are arranged concentrically with the gantry 1, and the inner side surfaces of the two devices 2 and 3 are opposed to each other.

The reflection / light receiving unit 4 includes a reflection / light receiving unit 2.
0, and a driving device 21 including a stepping motor for rotating the reflection / light receiver 20. The rotary shaft 22 of the drive device 21 is arranged concentrically with the gantry 1, and the reflection / light receiver 20 is fixed to the tip thereof.
As shown in FIGS. 4 to 6, the reflection / 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 portion 24 arranged on the back side of the mirror 23. The light receiving section 24 has a light receiving window 25 having an arc surface.
And a photomultiplier (photomultiplier) (not shown) arranged so as to face the light receiving window 25 in the reflection / light receiver 20. One photomultiplier tube may be provided, or a plurality of photomultiplier tubes may be provided so that light can be received for each channel.

The laser unit 5 contains, for example, a plurality of types of semiconductor laser systems each having an output of several 10 mW to 100 mW and different laser wavelengths, and wavelength selection is possible. Further, a collimator lens is provided in the laser unit 5. The laser unit 5 may have another configuration as long as it can realize a pencil beam.

Further, this optical CT apparatus has a control section 30 as shown in FIG. The control unit 30 includes the CPU 3
1. It includes a microcomputer having a ROM 32 and a RAM 33. In the I / O port 34 of the control unit 30, a keyboard 35 for inputting a command to the control unit 30, a CRT 36 for displaying an image based on an operation state and back projection processing (described later), and data of measurement results A printer 37 for printing out etc. is connected. Further, the I / O port 34 is connected to the laser unit 5, the reflection / light receiving unit 4, the shutter groups 13 and 15, and other input / output units 16. 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 described with reference to the control flowcharts shown in FIGS. When the program starts, in step S1 of FIG.
The laser unit 5 is activated, and initial settings such as setting the reflection / light receiver 20 to the initial position are performed. Step S
In 2, it is determined whether or not the measurement start key of the keyboard 35 has been pressed. In step S3, it is determined whether or not the projection start key of the keyboard 35 has been pressed. In step S4, it is determined whether the print start key has been pressed. Then, in step S5, a predetermined process other than the process related to the input key in steps S2 to S4 is executed. When the processing in step S5 ends, the process returns to step S2. When the operator sets the subject 6 in the gantry 1 as shown in FIG. 1 and presses the measurement start key of the keyboard 35, the program moves from step S2 to step S6 and executes the measurement subroutine of FIG. To do. In step S7 of FIG. 9, a laser emission start command is issued to the laser unit 5. As a result, the laser unit 5 starts emitting the laser light 5a.

In step S8, the reflection / light receiving unit 4
The reflection / light receiver 20 is set to the unit initial position. The unit here is a range in which the scanning operation is performed by using one mirror 12a of the mirror group 12. The unit initial position is, for example, the position of the mirror 23 set so that the laser beam 5a passes along the alternate long and short dash line A in FIG. Note that FIG. 10 is a developed partial view of the mirror groups 12 and 14 and the shutter groups 13 and 15. The black circles shown in the mirrors 12a and 14a of the mirror groups 12 and 14 and the liquid crystal shutters 13 and 15a of the shutter groups 13 and 15 are reflection points of the laser beam 5a.

In step S9 of FIG. 9, the reflection / light receiver 2
It is determined whether 0 has made one rotation (360 ° rotation).
This determination is made based on the rotation amount of the stepping motor in the drive device 21. If one rotation has not been performed, the process proceeds to step S10.

In step S10, the five liquid crystal shutters 13a and the five liquid crystal shutters 15a that receive the laser light 5a reflected by the mirror 12a facing the mirror 23 of the reflection / light receiver 20 are turned on, and the other liquid crystal shutters are turned on. 13a and 15a are turned off. As a result, the liquid crystal shutters 13a and 15a that are in the ON state are in a specular reflection state, and the remaining liquid crystal shutters 13a and 15a are in the state.
Becomes transparent. Therefore, the laser light 5a emitted from the laser unit 5 is refracted in the radial direction by the mirror 23 of the reflection / light receiver 20, passes through the liquid crystal shutter 13a, and is reflected by the mirror 12a in the direction parallel to the center line. Further, the laser light 5a passes through the liquid crystal shutter 15a and is reflected by the mirror 14a. In the mirror 14a, all the reflected light from the corresponding mirror 12a becomes parallel light and enters the subject 6 as shown in FIG. The laser beam 5a that has passed through the subject 6 has the liquid crystal shutter 15 in the ON state.
liquid crystal shutter 13a which is reflected by a and is in the ON state
And is incident on the light receiving portion 24 of the reflection / light receiver 20. The path of the laser beam 5a at this time is the one-dot chain line A in FIG.
Is.

The intensity of the laser light incident on the light receiving section 24 is
In step S11, the voltage value from the photomultiplier tube of the light receiving unit 24 is input to the control unit 30. Step S
At 12, the measured value is stored in RAM 33 along with the measured angle.

In step S13, the reflection / light receiving unit 4 is rotated by a minute unit. As a result,
The mirror 23 of the light receiver 20 is in a posture of reflecting the laser light 5a in the direction of the alternate long and short dash line B in FIG. Step S14
Then, it is determined whether or not the measurement is completed for one mirror 12a (that is, one measurement unit). here,
For example, as shown in FIG. 10, the measurement is performed on the five paths of the alternate long and short dash lines A to E, and the program proceeds to step S until the measurement of the route of the alternate long and short dash line E is completed.
Returning to step 11, the subsequent processing is repeated. This allows
Within one measurement unit, the subject 6 is scanned by the minute rotation of the reflection / light receiver 20 (step S13). As is clear from FIG. 10, the liquid crystal shutters 13a of the shutter group 13 are arranged in such a posture that the parallel paths of the laser light 5a are focused on the light receiving section 24.
Therefore, the laser light 5 a that scans the subject 6 in a fan shape is detected at one point on the light receiving unit 24.

When the measurement is completed for the five paths of the alternate long and short dash lines A to E in one measurement unit, the process returns from step S14 to step S8, and the reflection / light receiver 20 is set at the initial position of the next measurement unit. Then, the processes of steps S8 to S14 are repeated until it is determined in step S9 that the reflection / light receiving unit 4 has rotated once. As a result, the scanning is repeated with respect to the subject 6 at an angle of 360 °, and the respective data are stored in the RAM 33 of the control unit 30. Here, the laser light reflected by the reflection / light receiving unit 4 is one mirror 12 a of the mirror group 12.
Due to the difference in the incident angle when moving on the (plane), it spreads in a fan shape from the mirror group 12 to the mirror group 14.
It becomes a parallel beam at 4. Therefore, the reflection / light reception unit 4
If the rotation of the
Will be scanned over the entire circumference. Since the speed of this scanning is determined by the rotation speed of the reflection / light receiving unit 4, it is possible to measure at high speed over the entire circumference of the subject 6.

If the determination in step S9 is Yes,
The process moves to step S15 and the laser emission from the laser unit 5 is stopped. Then, the program returns to the main routine of FIG. At this stage, the data of the laser light absorption amount obtained by the scanning for each measurement unit is stored in the RAM 33.
It will be stored inside.

Next, in order to obtain a tomographic image (CT image) of the subject 6 based on the measurement result, the operator uses the keyboard 3
Press the projection start key of 5. by this,
The program proceeds from step S3 to step S16 and executes the projection subroutine. In addition,
Since the processing here is performed based on arithmetic processing such as data preprocessing, convolution, and back projection as in a general CT apparatus, detailed description will be omitted. Here, a tomographic image is displayed on the CRT 36 in, for example, 16-step gray scale. It should be noted that each part can be enlarged.

Further, in the present apparatus, since the mirror group 14 is composed of a plurality of parabolic mirrors 14a as described above, the reflected light from each point on the reflecting surface 16 of the parabolic mirror group 14a is reflected. All become parallel light and enter the subject 6.
On the other hand, when the mirror group 14 is composed of a large number of flat mirrors, the reflected laser light spreads in a fan shape as the laser light incident point on the flat mirror moves and moves toward the end. As a result, extra processing such as creating intermediate data using an interpolation method or the like is required for image processing, and the processing time becomes long. In this respect, in the present device, the reflected light from the mirror group 14 becomes parallel light, so that the calculation time can be shortened and the image quality can be improved. The program returns to the main routine when the processing in step S16 is completed.

To print out the obtained data or the like, the operator presses the print start key of the keyboard 35. As a result, the program moves from step S4 to step S17 and executes the print subroutine. Since the processing here is also similar to that of a normal CT apparatus, the description is omitted. When the processing in step S17 ends, the program returns to the main routine.

As described above, according to this embodiment, the measurement is performed by turning on / off the liquid crystal shutters 13a and 15a and rotating the reflection / light receiving unit 4 without rotating a large member such as the gantry 1. The fan-shaped scanning of the subject 6 can be performed over the entire circumference at high speed and in a short time.

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

In the above embodiment, the mirror group 14 is composed of a large number of parabolic mirrors 14a. However, the application of the present invention is not limited to this, and the mirror group 12 is composed of a large number of paraboloids. The mirror group 14 may be composed of plane mirrors and a large number of plane mirrors. In this case,
The focal points of the parabolic mirrors of the mirror group 12 are made to coincide with the mirror 23 of the reflection / light receiver 20. Mirror 2
The reflected light from 3 becomes parallel light after being reflected by each parabolic mirror of the mirror group 12 and enters the mirror group 14. And
The parallel beam from the mirror group 14 enters the subject 6.

Embodiment 2 FIG. 12 shows another embodiment of the present invention. In FIG. 12, the optical CT device is a gantry 4 having a cylindrical drum shape.
0 and the reflector 4 arranged concentrically in the gantry 40
1, a reflection / light receiving unit 42, and a laser unit 43 arranged concentrically behind the gantry 40 (on the right side in FIG. 12). The central axis of rotation of the reflection / light receiving unit 42 and the optical axis of the output light of the laser unit 43 coincide with each other.

The gantry 40 has a hole 45 in one end wall 40a into which the subject 44 is inserted, similar to the one shown in the first embodiment, so that the laser beam 43a from the laser unit 43 can be emitted. The other end wall 40b has a hole 46 passing therethrough.

As shown in FIG. 13, the reflecting device 41 has a mirror group 47 composed of a large number of parabolic mirrors 47a arranged in an annular shape, and a concentric and annular shape on the inner peripheral side of the mirror group 47. The shutter group 48 includes a large number of liquid crystal shutters 48a arranged. The parabolic mirror 47a is a mirror similar to the parabolic mirror 14a shown in FIG. Further, the focus of each parabolic mirror 47a is
Both are arranged on a mirror 49a (described later). The mirror group 47 and the shutter group 48 are inclined with respect to their center lines so as to form a part of a conical surface having an apex on the hole 45 side. Liquid crystal shutter 48a of shutter group 48
Is switched between an ON state and an OFF state under the control of the control unit. The liquid crystal shutter 48a is in a surface reflection state when it is in the ON state, and is in a transmission state when it is in the OFF state.

The reflection / light receiving unit 42 has a reflection / light receiving unit 49 and a drive unit 50 including a stepping motor for rotating the reflection / light receiving unit 49. The rotating shaft 51 of the driving device 50 is arranged concentrically with the gantry 40, and the reflection / light receiver 49 is fixed to the tip thereof. A mirror 49a is mounted on one surface of the reflection / light receiver 49, and the mirror 49a is mounted at a slight inclination with respect to the center line of the rotating shaft 50. The tilt angle θ of the mirror 49a is set such that the light from the laser unit 43 is reflected by the mirror group 47.
It is decided to reflect toward. Reflector / receiver 49
A light receiving portion 52 is provided on the back side of the. The light receiving portion 52 is provided with a light receiving window and a photomultiplier tube, which are not shown. In addition, each liquid crystal shutter 48 of the shutter group 48
The a is arranged in such a posture that the incident light from each flat mirror 47a of the mirror group 47 is reflected to the reflection / light receiving unit 42 side and focused on the light receiving portion 52.

The laser unit 43 has the same structure as that of the laser unit 5 shown in the first embodiment, and the description thereof is omitted here. Moreover, this optical CT apparatus has a control unit having the same configuration as the control unit 30 of the first embodiment. This device is controlled by this control unit.

Next, the operation will be described. As described above, the apparatus of the present embodiment has a configuration in which one of the reflecting devices is omitted from that shown in the first embodiment, and the operation of the present embodiment is substantially the same as the operation of the above-described first embodiment. Therefore, detailed description is omitted here. During the measurement, the liquid crystal shutter 48a of the shutter group 48 on which the reflected light from the reflection / light receiving unit 42 enters is turned off, and the liquid crystal of the shutter group 48 on which the laser light transmitted through the subject 44 enters. The shutter 48a is turned on.
As a result, the liquid crystal shutter 48a turned off.
Is in the translucent state, and the liquid crystal shutter 48 is in the ON state.
a is in a specular reflection state.

In this case, the laser beam 43a emitted by the laser unit 43 is reflected by the mirror 49a of the reflection / light receiver 49.
Reflected by. The reflected light from the reflection / light receiver 49 passes through the liquid crystal shutter 48a, is reflected by the mirror 47a in the direction orthogonal to the center line, and enters the subject 44. The laser beam 43 a that has passed through the subject 44 is reflected by the liquid crystal shutter 48 a in the ON state 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 unit 24. Therefore, the reflection
By rotating the light receiving unit 42 by 360 °, the subject 44 can be scanned with parallel beams from all directions, and a CT image can be obtained.

Also in this case, as in the first embodiment, the measurement is performed by turning on / off the liquid crystal shutter 48a and rotating the reflection / light receiving unit 42 without rotating the large member such as the gantry 40. , Subject 4
The fan-shaped scanning for 4 can be performed at high speed and in a short time over the entire circumference. Further, since the reflected light from each parabolic mirror 47a of the mirror group 47 becomes parallel light and enters the subject 44,
Processing can be performed in a shorter time. Moreover, as compared with the device of the first embodiment, one of the reflecting devices is omitted, so that the structure can be simplified and the cost can be reduced.

Embodiment 3 FIG. 14 shows still another embodiment of the present invention. Figure 1
4, the gantry 60, the reflection / light reception unit 6
3 and the laser unit 64 have the same configurations as those shown in the above-described second embodiment, and detailed description thereof will be omitted here.

Inside the gantry 60, primary and secondary reflecting devices 61 and 62 are arranged. The primary reflection device 61 has the same configuration as the mirror group 47 shown in FIG. 13, and has a large number of parabolic mirrors arranged in an annular shape. The focal points of the parabolic mirrors are all arranged on the mirror 65a of the reflection light receiver 65. The secondary reflecting device 62 is arranged concentrically with the primary reflecting device 61, but is not superposed. The secondary reflection device 62 is
It has a plurality of curved mirrors arranged at predetermined intervals on the circumference. The curvature of each curved mirror is formed so that the incident light from each plane mirror of the primary reflection device 61 is reflected to the reflection / light receiving unit 63 side and focused on the light receiving portion 67.

In this case, the laser light 64a emitted from the laser unit 64 is reflected by the mirror 65a of the reflection / light receiver 65 and enters the primary reflection device 61. The parallel light reflected by the parabolic mirror of the primary reflection device 61 passes through the subject 66 and the secondary reflection device 6
Incident on 2. The reflected light reflected by the curved mirror of the secondary reflecting device 62 is detected by the light receiving section 67 of the reflecting / light receiving unit 63. Also in this embodiment, the above-described first and second embodiments
In the same manner as above, scanning is performed over the entire circumference of the subject 66 while rotating the reflection / light receiving unit 63.

Also in this case, the above-described first and second embodiments
Similarly, since the measurement is performed by rotating the reflection / light receiving unit 63 without rotating a large member such as the gantry 60, the parallel beam scanning of the object 66 can be performed over the entire circumference at high speed and in a short time. Moreover, unlike the first and second embodiments, since each reflecting device is configured only by the mirror without using an expensive liquid crystal shutter, a more inexpensive device can be realized.

Embodiment 4 FIGS. 15 to 17 show still another embodiment of the present invention. The optical CT device includes a reflecting device 71 arranged in the gantry 70, a mirror 72, a light receiving section 73, and a laser unit 74. Here, the laser unit 74 is arranged in the gantry 70 between the subject 75 and the mirror 72, which is different from the above-described embodiments. By disposing the laser unit 74 in the gantry 70 in this way, the entire apparatus can be made compact. Further, as compared with the devices of Examples 2 and 3, the mirror 7
There is an advantage that the incident angle θ of the laser light on 2 can be made small, which facilitates adjustment of each part. The first
The incident angle θ is θ = 30 ° in Fig. 0 and θ <in Fig. 11.
30 °, and FIG. 12 shows θ> 30 °.

The reflecting device 71 is similar to the reflecting device 41 (FIG. 13) shown in the second embodiment, and includes a mirror group 76 composed of a large number of parabolic mirrors and an inner peripheral side of the mirror group 76. And a shutter group 77 arranged concentrically with each other. The mirror group 76 and the shutter group 77 correspond to the mirror group 47 and the shutter group 48 of FIG. 13, respectively. 15 to 16, the mirror group 76 and the shutter group 77 have different inclination angles with respect to the center line.

On the rear side of the mirror 72 (on the right side of each drawing),
A drive device 78 for rotationally driving the mirror 72 is arranged. The rotating shaft 79 of the drive device 78 is a gantry 70.
And the mirror 72 is fixed to the tip thereof. In addition, in the device shown in FIG.
A light receiving portion 73 is provided on the side portion of. This is because the reflected laser light reflected by the shutter group 77 enters the side portion of the mirror 72. In the device of FIG. 16, the light receiving unit 73 is arranged in a ring shape around the mirror 72 in the gantry 70. This is because the reflected laser light from the shutter group 77 is incident on the reflecting surface of the mirror 72, so that the reflected laser light from the mirror 72 is detected. In the device of FIG. 17, since the laser light reflected by the shutter group 77 is incident on the back side of the mirror 72, the light receiving unit 7
3 is provided on the back side of the mirror 72.

Next, the operation will be described. As described above, the apparatus of the present embodiment has a configuration in which the laser unit 43 is arranged in the gantry 40 in the apparatus (FIG. 12) shown in the second embodiment, and the operation of the present embodiment is the same as that of the second embodiment. Since the operation is substantially the same as that of 1., detailed description will be omitted here. During the measurement, the liquid crystal shutters of the shutter group 77 on which the reflected light from the mirror 72 enters are turned off and are in the translucent state, and the liquid crystal of the shutter group 77 on which the laser light transmitted through the subject 75 enters. The shutter is turned on and enters a specular reflection state.

The laser light emitted from the laser unit 74 is
It is reflected by the mirror 72. The reflected laser light passes through the liquid crystal shutters of the shutter group 77, is reflected by the mirrors of the mirror group 76 in the direction orthogonal to the center line, and enters the subject 75. The laser light that has passed through the subject 75 is reflected by the liquid crystal shutters in the ON state of the shutter group 77 and enters the light receiving unit 73. Then, the intensity of the incident laser light is measured by the light receiving unit 73. Further, similarly to each of the above-described embodiments, the mirror 72 is rotated by the driving device 78 and scanning is performed over the entire circumference of the subject 75.

Also in this case, since the measurement is performed by rotating the mirror 72 without rotating the large member such as the gantry 70, the scanning of the object 75 by the parallel beam can be performed over the entire circumference at high speed and in a short time. Moreover, unlike the above-described respective embodiments, the laser unit 74 is arranged between the subject 75 and the mirror 72 in the gantry 70, so that the apparatus can be made compact. Also,
Since the incident angle θ of the laser light incident on the mirror 72 from the laser unit 74 can be reduced, adjustment of each part can be easily performed.

Embodiment 5 FIG. 18 shows still another embodiment of the present invention. Figure 1
8, the same reference numerals as those in the fourth embodiment shown in FIGS. 15 to 17 indicate the same or corresponding parts. Also in the apparatus of the present embodiment, as in the apparatus of the fourth embodiment, the laser unit 74 is arranged between the subject 75 and the mirror 72 in the gantry 70, which makes the apparatus compact and facilitates adjustment of each part. Is being pursued. Further, in the apparatus of this embodiment,
The reflecting device 80 for reflecting the light reflected by the mirror 72 is different from that shown in the fourth embodiment.

This reflecting device 80 is similar to the reflecting device (FIG. 14) shown in the third embodiment, and is composed of a primary reflecting device 81 and a secondary reflecting device 82. The primary reflection device 81 is similar to the primary reflection device 61 of FIG.
The secondary reflecting device 82 corresponds to the secondary reflecting device 62 shown in FIG. The light receiving portion 73 is arranged in a ring shape on the side of the reflecting device 80.

Next, the operation will be described. In this case, as in the case of the third embodiment, the laser light emitted from the laser unit 74 is reflected by the primary reflection device 81,
The laser light reflected by the secondary reflecting device 82 after passing through the subject 75 and entering the secondary reflecting device 82 is received by the light receiving portion 73.
Detected in. Then, the mirror 72 is rotated in the same manner as in the above-described respective embodiments, and scanning is performed over the entire circumference of the subject 75.

Also in this case, it is not necessary to rotate a large member such as the gantry 70, and the scanning of the subject 75 can be performed over the entire circumference at high speed and in a short time. Moreover,
Since the laser unit 74 is arranged in the gantry 70, the entire device can be made compact and each part can be easily adjusted. Further, since the reflecting device 80 is composed of only the mirror, an inexpensive device can be realized.

[0054]

Since the optical scanning device according to the present invention is provided with the above-described mirror and the first and second reflecting portions, the subject can be measured at high speed over the entire circumference without rotating a large member. it can. Therefore, according to the present invention, it is possible to realize an optical scanning device capable of obtaining information in the subject at high speed and in a short time.

Moreover, since the first reflecting portion has a parabolic reflecting surface, the incident light on the subject becomes a parallel beam, which allows the processing to be further speeded up.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of an embodiment of the present invention.

FIG. 2 is an exploded schematic diagram thereof.

FIG. 3 is a perspective view of a parabolic mirror.

FIG. 4 is a front view of a reflection / light receiver.

FIG. 6 is a side view of a reflection / light receiver.

FIG. 6 is a bottom view of the reflection / light receiver.

FIG. 7 is a schematic block diagram of a control unit according to an embodiment of the present invention.

FIG. 8 is a control flowchart thereof.

FIG. 9 is a control flowchart thereof.

FIG. 10 is a developed partial view of a path of laser light.

FIG. 11 is a diagram showing a reflection state on a parabolic mirror.

FIG. 12 is a schematic vertical sectional view of another embodiment of the present invention.

FIG. 13 is an exploded schematic view of the reflecting device.

FIG. 14 is a schematic vertical sectional view of another embodiment.

FIG. 15 is a schematic vertical sectional view of another embodiment.

FIG. 16 is a schematic vertical sectional view of another embodiment.

FIG. 17 is a schematic vertical sectional view of another embodiment.

FIG. 18 is a schematic vertical sectional view of another embodiment.

[Explanation of symbols]

 4, 42, 63 Reflecting / receiving unit 23, 72 Mirror 5, 43, 64, 78 Laser unit 5a, 43a, 64a Laser light 6, 44, 66, 75 Specimen 12, 14, 47, 61, 76, 81 Mirror Group 12a, 14a, 47a Mirror 13, 15, 48, 77 Shutter group 13a, 15a, 48a Liquid crystal shutter 24, 52, 67, 73 Light receiving part 62, 82 Secondary reflection device

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[Procedure amendment]

[Submission date] September 1, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of an embodiment of the present invention.

FIG. 2 is an exploded schematic diagram thereof.

FIG. 3 is a perspective view of a parabolic mirror.

FIG. 4 is a front view of a reflection / light receiver.

FIG. 5 is a side view of a reflection / light receiver.

FIG. 6 is a bottom view of the reflection / light receiver.

FIG. 7 is a schematic block diagram of a control unit according to an embodiment of the present invention.

FIG. 8 is a control flowchart thereof.

FIG. 9 is a control flowchart thereof.

FIG. 10 is a developed partial view of a path of laser light.

FIG. 11 is a diagram showing a reflection state on a parabolic mirror.

FIG. 12 is a schematic vertical sectional view of another embodiment of the present invention.

FIG. 13 is an exploded schematic view of the reflecting device.

FIG. 14 is a schematic vertical sectional view of another embodiment.

FIG. 15 is a schematic vertical sectional view of another embodiment.

FIG. 16 is a schematic vertical sectional view of another embodiment.

FIG. 17 is a schematic vertical sectional view of another embodiment.

FIG. 18 is a schematic vertical sectional view of another embodiment.

[Explanation of Codes] 4,42,63 Reflecting / Receiving Unit 23,72 Mirrors 5,43,64,78 Laser Units 5a, 43a, 64a Laser Light 6,44,66,75 Subject 12,14,47,61 , 76, 81 Mirror group 12a, 14a, 47a Mirror 13, 15, 48, 77 Shutter group 13a, 15a, 48a Liquid crystal shutter 24, 52, 67, 73 Light receiving part 62, 82 Secondary reflection device

Claims (1)

[Claims] 1. An optical scanning device for obtaining information within a subject by using a light beam, comprising: a light emitting means for emitting the light beam; and a light emitting means arranged on the optical axis of the light beam, in a direction intersecting the optical axis. A rotatable mirror for reflecting the light beam; a light receiving means for measuring the intensity of incident light; and a circular ring-shaped arrangement for receiving the light beam reflected by the mirror and reflecting it in a plane intersecting the optical axis, and A first reflecting portion having a parabolic reflecting surface; and a first reflecting portion which receives the light beam from the first reflecting portion and reflects the light beam toward the light receiving means, and which is arranged concentrically with the first reflecting portion and in an annular shape. An optical scanning device comprising: two reflectors.