Beam limiting device for CBCT (cone beam computed tomography)

Abstract

The utility model discloses a beam limiting device for CBCT, which relates to the technical field of beam limiting devices and comprises a bottom plate, a filtering portion, a shading portion, a mainboard portion and a circuit board portion are mounted on the bottom plate, the mainboard portion comprises a second mounting plate, a first lead hinge fitting, a second lead hinge fitting and a third lead hinge fitting, the second mounting plate is mounted on the bottom plate through a bi-pass hexagonal stud, and the second lead hinge fitting is mounted on the bottom plate through the bi-pass hexagonal stud. A first lead hinge assembly and a second lead hinge assembly are arranged on one side face of the second installation plate in the X direction in a sliding mode, and two third lead hinge assemblies are arranged on the other side face of the second installation plate in the Y direction in a sliding mode. According to the mode that the independent lead screw motor drives the lead hinge assembly, the lead hinges limiting the X-rays in the four directions of the beam limiting device independently and continuously move according to a system program, and meanwhile the purpose that the center of the X-ray range deviates from the center of the beam limiting device is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of beam limiters, in particular to a beam limiter used for CBCT. Background Art

[0002] The full name of CBCT is Cone beam Computer Tomography, which is a cone beam computer tomography system. Its principle is that the X-ray generator uses a low radiation dose (usually the tube current is about 10 mA) to perform circular digital projection around the projection object, and the data obtained by "intersecting" after multiple (180-360 times) digital projections around the projection object is "reconstructed" in the computer to obtain a three-dimensional image. Its X-ray generating device is mainly composed of a high-voltage generator, a tube and a beam limiter. The beam limiter is usually located under the tube, and the X-rays emitted by the tube are irradiated onto the object to be examined through the beam limiter.

[0003] The beam limiter, also known as "line blocker", "light shrinker" or "beamer", is used to limit the irradiation range of X-rays emitted from the tube, so as to minimize the dose of X-rays received by the inspection object. The beam limiter generally includes a base plate, a filter part, a light shielding part, a main board part and a shell. The base plate, the filter part, the light shielding part and the main board part are installed in the shell. The filter part can be rotated by the program to automatically select different aluminum equivalent filters. The light shielding part can prevent X-ray leakage and protect the operator and the projection object. The main board part is used to control the size of the beam limiter opening, thereby determining the irradiation range of the X-rays.

[0004] However, the existing technology has the following shortcomings and deficiencies. Since the CBCT-DR system requires the X-ray generator to "reconstruct" the data obtained by "intersection" after multiple (180-360 times) digital projections around the projection object in the computer, the lead sheet that limits the X-ray in the four directions of the beam limiter needs to move independently and continuously according to the system program, and at the same time, the center of the X-ray range deviates from the center of the beam limiter. The old beam limiter can only allow the lead sheet to move relatively, and cannot move independently and continuously, while the center of the X-ray range is consistent with the center of the beam limiter. Utility Model Content

[0005] In view of the shortcomings of the prior art, the utility model provides a beam limiter for CBCT, which changes the original beam limiter that can only allow the lead sheet to move relatively in a single direction, and at the same time realizes that the center of the X-ray range deviates from the center of the beam limiter.

[0006] To achieve the above objectives, the utility model is implemented through the following technical solutions: A beam limiter for CBCT, comprising a bottom plate, on which a filtering part, a light shielding part, a main board part, and a circuit board part are installed;

[0007] The light shielding part comprises a mounting plate 1 and a light shielding tube assembly, wherein the mounting plate 1 is fixedly mounted on the bottom plate via a supporting copper column, and the light shielding tube assembly is fixedly mounted on the mounting plate 1, wherein the light shielding tube assembly is riveted together by two half tubes, and two protective plates are fixedly arranged on the outer walls of the two half tubes;

[0008] The main board portion includes a mounting plate 2, a lead sheet joint 1, a lead sheet joint 2, and a lead sheet joint 3. The mounting plate 2 is mounted on the bottom plate by means of a double-through hexagonal stud. The lead sheet joint 1 and the lead sheet joint 2 are slidably arranged on one side of the mounting plate 2 along the X direction. Two lead sheet joints 3 are slidably arranged on the other side of the mounting plate 2 along the Y direction. The lead sheet 1 is installed in the lead sheet joint 1, the lead sheet 2 is installed in the lead sheet joint 2, and the lead sheet 3 is installed in the lead sheet joint 3. A motor joint 1 for driving the lead sheet joint 1 to move is installed on one side of the mounting plate 2, and a motor joint 2 for driving the lead sheet joint 2 to move is installed on one side of the lead sheet joint 1 and one side of the lead sheet joint 2 and the two lead sheet joints 3 on the mounting plate 2.

[0009] Preferably, linear guide rails are arranged on both side surfaces of the second mounting plate, and the first lead sheet joint, the second lead sheet joint, and the two third lead sheet joints are respectively mounted on the sliders of the linear guide rails.

[0010] Preferably, the motor assembly one includes a screw motor one and a support seat one, the support seat one is screwed onto the screw of the screw motor one, the screw motor one is fixedly mounted on the mounting plate two through the motor seat, the motor assembly two includes a screw motor two and a support seat two, the support seat two is screwed onto the screw of the screw motor two, the screw motor two is fixedly mounted on the mounting plate two through the motor seat, the screw motor one.

[0011] Preferably, the lead sheet joint 1 and the lead sheet joint 2 have the same structure, both comprising a lead sheet clamping plate 1, a lead sheet pressure plate 1, a connecting plate 1 and a baffle 1. The connecting plate 1 is fixedly connected to the lead sheet clamping plate 1 through the upper end positioning holes of the lead sheet and the lead sheet pressure plate 1 by means of pan head screws. The baffle 1 is fixedly connected to the lead sheet clamping plate 1 through the lower end positioning holes of the lead sheet and the lead sheet pressure plate by means of pan head screws. The connecting plate 1 and the baffle 1 are fixedly connected to the slider in the linear guide rail. The connecting plate 1 in the lead sheet joint 1 and the lead sheet joint 2 are respectively connected to the support seat 1 and the support seat 2. An optical coupler 1 is fixedly provided on the mounting plate 2 located on one side of the lead sheet joint 1 and the lead sheet joint 2. When the lead sheet joint 1 or the lead sheet joint 2 moves, the baffle 1 can slide across the optical coupler 1.

[0012] Preferably, the lead sheet joint part three includes lead sheet clamping plate two, lead sheet three, lead sheet pressure plate two, connecting plate two, and baffle plate two. The connecting plate two is fixed to the lead sheet clamping plate two by pan head screws through the upper end positioning holes of the lead sheet three and the lead sheet pressure plate two. The baffle plate two is fixedly connected to the lead sheet clamping plate two by pan head screws through the lower end positioning holes of the lead sheet three and the lead sheet pressure plate two. The connecting plate two and the baffle plate two are fixedly connected to the slider in the linear guide rail. The connecting plate two is connected to the support seat two. Optical couplers two are fixedly provided on the mounting plates two located on one side of the two lead sheet joint parts three. When the lead sheet joint part three moves, the baffle plate two can slide over the optical couplers two.

[0013] Preferably, the filtering part includes a filtering gear, a filter plate, a circular hole, and a stepper motor. A filtering shaft is fixedly arranged on the bottom plate, the filtering gear is rotatably mounted on the filtering shaft, the filter plate is fixedly mounted on the filtering gear, a stepper motor is fixedly arranged on the bottom plate at one side of the filtering gear through a filtering motor bracket, and a driving gear meshing with the filtering gear is fixedly mounted on the driving end of the stepper motor.

[0014] Preferably, a gear optical coupler is fixedly arranged on the bottom plate, and a circular hole is opened on the filtering gear, and the circular hole can pass through the gear optical coupler notch when the filtering gear rotates.

[0015] Preferably, the circuit board portion includes a CBCT circuit board, an insulating spacer column, and a support plate. The CBCT circuit board is fixed to the support plate by means of pan head screws passing through the center holes of the insulating spacers, and the support plate is fixedly connected to the base plate by means of countersunk screws.

[0016] Beneficial Effects

[0017] The utility model provides a beam limiter for CBCT, which has the following beneficial effects: by redesigning the movement mode of the lead sheet of the main board assembly, that is, by driving the lead sheet assembly through an independent screw motor, the lead sheets for limiting X-rays in four directions of the beam limiter can move independently and continuously according to the system program, and at the same time, the center of the X-ray range can deviate from the center of the beam limiter. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the main internal structure diagram of the utility model;

[0019] Figure 2 is a three-dimensional diagram of the filtration unit;

[0020] Figure 3 A three-dimensional diagram of a filter disc assembly;

[0021] Figure 4 is a three-dimensional diagram of a stepper motor;

[0022] Figure 5is a three-dimensional diagram of a stepper motor;

[0023] Figure 6 is a three-dimensional diagram of the light-shielding portion;

[0024] Figure 7 It is a three-dimensional diagram of the circuit board part;

[0025] Figure 8 The main board is three-dimensional Figure 1 ;

[0026] Fig. 9 The main board is three-dimensional Figure 2 ;

[0027] Fig.10 A three-dimensional diagram of a lead sheet assembly;

[0028] Fig.11 It is a three-dimensional diagram of the motor assembly 1;

[0029] Fig.12 is a three-dimensional diagram of the lead screw support;

[0030] Fig.13 is a stereogram of an optical coupler 1;

[0031] Fig.14 It is a three-dimensional diagram of lead sheet assembly 2;

[0032] Fig.15 It is a three-dimensional diagram of the second motor assembly;

[0033] Fig.16 It is a three-dimensional diagram of lead sheet assembly 3;

[0034] Fig.17 This is a three-dimensional diagram of the bottom plate optocoupler 2.

[0035] In the figure: 1, bottom plate assembly; 11, connecting ring; 12, bottom plate; 13, filter shaft; 2, filter part; 21, filter disc assembly; 211, filter gear; 212, filter plate; 213, filter sleeve; 214, round hole; 22, filter motor assembly; 221, stepper motor; 222, filter motor bracket; 223, driving gear; 23, gear optical coupling; 24, optical coupling pressure plate; 3, shading part; 31, shading cylinder assembly; 311, half cylinder; 312, protective plate; 32, mounting plate 1; 33, supporting copper column; 4, double-pass hexagonal stud; 5, main board; 51, mounting plate 2; 52, lead sheet assembly 1; 521, lead sheet clamp 1; 522, lead sheet 1; 523, lead sheet pressure plate 1; 524, connecting plate 1; 525, baffle 1; 53, motor assembly 1; 531, screw motor 1; 532, support seat 1; 54, linear guide; 55, screw bracket assembly; 551, screw bracket; 552, adjustment plate; 56, optical coupler 1; 561, optical coupler pad; 562, slotted optical coupler; 57, lead sheet assembly 2; 572, lead sheet 2; 58, guide rail baffle; 59, motor assembly 2; 591, screw motor 2; 592, support seat 2; 510, optical coupler 2; 511, lead sheet assembly 3; 5111, lead sheet clamp 2; 5112, lead sheet 3; 5113, lead sheet pressure plate 2; 5114, connecting plate 2; 5115, baffle 2; 6, circuit board; 61, CBCT circuit board; 62, insulating pad column; 63, support plate; 7, shell; 71, front cover. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0037] See also Figure 1-17 The utility model provides a technical solution: a beam limiter, which includes: a bottom plate assembly 1, a filtering part 2, a shading part 3, a supporting copper column 4, a circuit board part 5, a circuit board part 6, and a shell part.

[0038] As an embodiment of the present utility model, Figure 1 , Figure 2 As shown. The bottom plate assembly 1 includes a ring 11, a bottom plate 12, and a filter shaft 13. The filter shaft 13 is welded to the bottom plate 12 for rotating the filter part 2. The ring 11 is connected to the bottom plate 12 by a countersunk screw to ensure that the limiter is located at a relative position inside the tube.

[0039] As an embodiment of the present utility model, Figure 3 As shown, the filter unit 2 is composed of a filter disc assembly 21, a filter motor assembly 22, a gear optical coupler 23, and an optical coupler pressure plate 24. The filter disc assembly 21 is composed of Figure 4As shown, the filter disc assembly 21 is composed of a filter gear 211, a filter sheet 212, and a filter sleeve 213. The filter sheets 212 of three material thicknesses are fixed to the filter gear 211 by metal glue and hollow rivets. The filter sleeve 213 is fixed to the filter gear 211 by a pan head screw. The filter disc assembly 21 passes the center hole of the filter sleeve 213 through the filter shaft 13, and the upper end is fixed with a copper gasket and an open retaining ring, so that the filter disc assembly 21 can rotate freely on the shaft without falling off.

[0040] As an embodiment of the present utility model, Figure 5 As shown, the filter motor assembly 22 consists of a stepper motor 221, a filter motor bracket 222, and a driving gear 223. The stepper motor 221 is fixed to the filter motor bracket 222 by a countersunk screw, and the filter gear 223 is fixed to the stepper motor 221 by a set screw. The filter motor assembly 222 is fixed to the base plate 12 by a hexagon socket head screw, and the driving gear 223 is meshed with the filter gear 211, and the stepper motor 221 drives the filter gear 211 to rotate.

[0041] As an embodiment of the present utility model, Figure 3 As shown, the gear optical coupler 23 is installed on the countersunk hole of the bottom plate 12, and the optical coupler pressure plate 24 is installed on the upper end, and fixed to the bottom plate 12 by countersunk screws. The filter disc assembly 21 rotates on the filter shaft 13, and a circular hole 214 of φ1 is provided on the filter gear 211 to ensure that the circular hole φ1 passes through the gap of the gear optical coupler 23 when the filter gear 211 rotates. The stepper motor 221 is connected to the motor control system through electrical control. The filter part 2 can be automatically controlled by the motor control system. The CBCT circuit board 61 gives an electrical signal, the filter disc assembly 21 is reset, the circular hole 214 on the gear 211 passes through the gear optical coupler 23, and the hollowed-out part of the filter disc assembly 21 is aligned with the light inlet hole of the bottom plate 12. The CBCT circuit board 61 gives a signal, the filter disc assembly 21 rotates, and according to the number of signal pulses, the filter 212 makes the filter of the corresponding material thickness face the light inlet hole of the bottom plate 11.

[0042] As an embodiment of the present utility model, Figure 6 As shown, the light shielding part 3 is composed of a light shielding cylinder assembly 31, a mounting plate 1 32, and a supporting copper column 33. The light shielding cylinder assembly 31 is composed of a half cylinder 311 and a protective plate 312. The two ends of the two half cylinders 311 are electrically riveted together, and the two protective plates 312 are bonded to the outer wall. The light shielding cylinder assembly 31 is fixed to the mounting plate 1 32 by countersunk screws. The mounting plate 1 32 is fixed to the upper end of the supporting copper column 33 by countersunk screws, and the lower end of the supporting copper column 33 is fixed to the bottom plate 12 by countersunk screws.

[0043] As an embodiment of the present utility model, Figure 1As shown, four double-pass hexagonal studs 4 are fixed to the bottom plate 12 by countersunk screws. The main plate portion 5 is fixed to the double-pass hexagonal studs 4 by countersunk screws.

[0044] As an embodiment of the present utility model, Figure 7 As shown, the circuit board part 6 is composed of a CBCT circuit board 61, an insulating column 62, and a support plate 63. The CBCT circuit board 61 is fixed to the support plate 63 by a pan head screw passing through the center hole of the insulating column 62. The support plate 63 is fixed to the base plate 12 by a countersunk screw.

[0045] As an embodiment of the present utility model, Figure 8 , Fig. 9 As shown, the main board part 5 is composed of a mounting plate 2 51, a lead sheet assembly 1 52, a motor assembly 1 53, a linear guide rail 54, a lead screw bracket assembly 55, an optical coupler 1 56, a lead sheet assembly 2 57, a guide rail baffle 58, a motor assembly 2 59, an optical coupler 2 510, and a lead sheet assembly 3 511.

[0046] In the X1 direction, the linear guide rail 54 is fixed to the mounting plate 2 51 by means of pan head screws, and the guide rail baffles 58 at both ends are fixed by means of pan head screws. Fig.10 As shown, the lead sheet assembly 52 is composed of a lead sheet clamp 521, a lead sheet 522, a lead sheet pressure plate 523, a connecting plate 524, and a baffle 525. The connecting plate 524 is fixed to the lead sheet clamp 521 with a pan head screw through the upper positioning holes of the lead sheet 522 and the lead sheet pressure plate 523. The baffle 525 is fixed to the lead sheet clamp 521 with a pan head screw through the lower positioning holes of the lead sheet 522 and the lead sheet pressure plate 523. The lead sheet assembly 52 is fixed to the slider of the linear guide 54 through the positioning holes on both sides of the connecting plate 524 and the baffle 525. Ensure that the lead sheet assembly 52 slides freely and parallel on the linear guide 54. By Fig.11 As shown, the motor assembly 53 is composed of a screw motor 531, a motor seat, and a support seat 532. The support seat 532 is screwed onto the screw of the screw motor 531. When the screw rotates, the support seat 532 can move along its axial direction. The screw motor 531 is fixed to the motor seat by countersunk screws. The motor seat is fixed to the mounting plate 51 by countersunk screws. Fig.12As shown, the screw support assembly 55 is composed of a screw support 551 and an adjustment plate 552. The adjustment plate 552 is fixed to the screw support 551 by a pan head screw, and the screw support 551 is fixed to the mounting plate 251 by a countersunk screw through the threaded hole at the lower end. Adjust the pan head screw on the adjustment plate 552 so that the shaft end of the screw motor 1531 passes through the positioning hole of the adjustment plate 552, so that the support seat 1532 can only move between the motor seat and the screw support assembly 55. The lead leaf assembly 152 is connected to the support seat 1532 by a pan head screw through the threaded hole on the connecting plate 1524, ensuring that when the screw motor 1531 is running, the support seat 1532 moves evenly on the screw, driving the lead leaf assembly 152 to move at a uniform speed. Fig.13 As shown, the optical coupler 156 is composed of an optical coupler pad 561 and a slot optical coupler 562. The slot optical coupler 562 is fixed to the optical coupler pad 561 by a pan head screw, and the optical coupler pad 561 is fixed to the mounting plate 251 by a pan head screw. When the lead sheet joint 152 is ensured to move at a uniform speed, the baffle 1525 passes through the slot optical coupler 562. The lead screw motor 1531 is connected to the CBCT circuit board 61 through a cable. In the X1 direction, the CBCT circuit board 61 gives a signal, the lead screw motor 1531 rotates, and the support seat 1532 moves, driving the lead sheet joint 152 to move independently. According to the number of electrical signal pulses, the lead sheet joint 152 moves to the set position according to the corresponding number of steps, that is, the position where the X-ray deviates from the center line. The electrical signal changes direction, causing the lead sheet joint 152 to run to the farthest end, and the baffle 1525 passes through the gap of the slot optical coupler 562, and the lead sheet is reset to the maximum in the X1 direction.

[0047] In the X2 direction, the linear guide rail 54 is fixed to the mounting plate 2 51 by means of pan head screws, and the guide rail baffles 58 at both ends are fixed by means of pan head screws. Fig.14 As shown, the lead sheet assembly 2 57 is composed of a lead sheet clamp 1 521, a lead sheet 572, a lead sheet pressure plate 1 523, a connecting plate 1 524, and a baffle 1 525. The connecting plate 1 524 is fixed to the lead sheet clamp 1 521 with a pan head screw through the upper positioning holes of the lead sheet 2 572 and the lead sheet pressure plate 1 523. The baffle 1 525 is fixed to the lead sheet clamp 1 521 with a pan head screw through the lower positioning holes of the lead sheet 2 572 and the lead sheet pressure plate 1 523. The lead sheet assembly 2 57 is fixed to the slider of the linear guide 54 through the positioning holes on both sides of the connecting plate 1 524 and the baffle 1 525. It is ensured that the lead sheet assembly 2 57 slides freely and parallelly on the linear guide 54. By Fig.15It indicates that the motor assembly 259 is composed of a screw motor 2591, a motor seat, and a support seat 2592. The support seat 2592 is screwed onto the screw of the screw motor 2591, and the screw motor 2591 is fixed to the motor seat by countersunk screws. The motor seat is fixed to the mounting plate 251 by countersunk screws. The screw support assembly 55 is fixed to the mounting plate 251 by countersunk screws through the threaded holes at the lower end. The pan head screw on the adjustment plate 552 is adjusted so that the shaft end of the screw motor 2591 passes through the positioning hole of the adjustment plate 552, so that the support seat 2592 can only move between the motor seat and the screw support assembly 55. The lead sheet assembly 257 is connected to the support seat 2592 by pan head screws through the threaded holes on the connecting plate 1524, ensuring that when the screw motor 2591 is running, the support seat 2592 moves evenly on the screw, driving the lead sheet assembly 257 to move at a uniform speed. The optical coupling 56 is fixed to the mounting plate 251 by pan head screws. When ensuring that the lead sheet joint 2 57 moves at a uniform speed, the baffle 1 525 passes through the slotted optical coupler 562. The lead screw motor 2 591 is connected to the CBCT circuit board 61 through a cable. In the X2 direction, the CBCT circuit board 61 gives a signal, the lead screw motor 2 591 rotates, the support seat 2 592 moves, and the lead sheet joint 2 57 moves independently. According to the number of electrical signal pulses, the lead sheet joint 2 57 moves to the set position according to the corresponding number of steps, that is, the position where the X-ray deviates from the center line. The electrical signal changes direction, causing the lead sheet joint 2 57 to run to the farthest end, and the baffle 1 525 passes through the notch of the slotted optical coupler 562, and the lead sheet is reset to the maximum in the X2 direction.

[0048] In the Y1 direction, the linear guide rail 54 is fixed to the mounting plate 2 51 by means of pan head screws, and the guide rail baffles 58 at both ends are fixed by means of pan head screws. Fig.16As shown, the lead sheet assembly 3 511 is composed of the lead sheet clamping plate 2 5111, the lead sheet 3 5112, the lead sheet pressure plate 2 5113, the connecting plate 2 5114, and the baffle 2 5115. The connecting plate 2 5114 is fixed to the lead sheet clamping plate 2 5111 by pan head screws through the upper positioning holes of the lead sheet 3 5112 and the lead sheet pressure plate 2 5113. The baffle 2 5115 is fixed to the lead sheet clamping plate 2 5111 by pan head screws through the lower positioning holes of the lead sheet 3 5112 and the lead sheet pressure plate 2 5113. The lead sheet assembly 3 511 is fixed to the slider of the linear guide 54 through the positioning holes on both sides of the connecting plate 2 5114 and the baffle 2 5115. Ensure that the lead sheet assembly 511 slides freely and parallelly on the linear guide 54. The motor assembly 2 59 is fixed to the mounting plate 2 51 by countersunk screws. The lead screw support assembly 55 is fixed to the mounting plate 2 51 through the threaded hole at the lower end using a countersunk screw. Adjust the pan head screw on the adjustment plate 552 so that the shaft end of the lead screw motor 2 591 passes through the positioning hole of the adjustment plate 552, so that the support seat 2 592 can only move between the motor seat and the lead screw support assembly 55. The lead leaf assembly 3 511 is connected to the support seat 2 592 through the threaded hole on the connecting plate 1 524 using a pan head screw to ensure that when the lead screw motor 2 591 is running, the support seat 2 592 moves evenly on the lead screw, driving the lead leaf assembly 3 511 to move at a uniform speed. Fig.17 As shown, the optical coupler 2 510 is composed of an optical coupler pad 5101 and a slot optical coupler 5102. The slot optical coupler 5102 is fixed to the optical coupler pad 5101 by a pan head screw, and the optical coupler pad 5101 is fixed to the mounting plate 2 51 by a pan head screw. When the lead sheet joint 3 511 is ensured to move at a uniform speed, the baffle 2 5115 passes through the slot optical coupler 5102. The lead screw motor 2 591 is connected to the CBCT circuit board 61 through a cable. In the Y1 direction, the CBCT circuit board 61 gives a signal, the lead screw motor 2 591 rotates, and the support seat 2 592 moves, driving the lead sheet joint 3 511 to move independently. According to the number of electrical signal pulses, the lead sheet joint 3 511 moves to the set position according to the corresponding number of steps. The electrical signal changes direction, so that the lead sheet joint 3 511 runs to the farthest end, and the baffle 2 5115 passes through the notch of the slot optical coupler 5102, and the lead sheet is reset to the maximum in the Y1 direction.

[0049] In the Y2 direction, the linear guide 54 is fixed to the mounting plate 2 51 by pan head screws, and the guide baffles 58 at both ends are fixed by pan head screws. The lead leaf joint 3 511 is fixed to the slider of the linear guide 54 through the positioning holes on both sides of the connecting plate 2 5114 and the baffle 2 5115. Ensure that the lead leaf joint 511 slides freely and parallelly on the linear guide 54. The motor joint 2 59 is fixed to the mounting plate 2 51 by countersunk screws. The screw bracket joint 55 is fixed to the mounting plate 2 51 by countersunk screws through the threaded holes at the lower end. Adjust the pan head screw on the adjustment plate 552 so that the shaft end of the screw motor 2 591 passes through the positioning hole of the adjustment plate 552, so that the support seat 2 592 can only move between the motor seat and the screw bracket joint 55. The lead sheet joint part 3 511 is connected to the support seat 2 592 through the threaded hole on the connecting plate 1 524 with a pan head screw, ensuring that when the lead screw motor 2 591 is running, the support seat 2 592 moves evenly on the lead screw, driving the lead sheet joint part 3 511 to move at a uniform speed. The optical coupler 2 510 is fixed to the mounting plate 2 51 by a pan head screw. When ensuring that the lead sheet joint part 3 511 moves at a uniform speed, the baffle 2 5115 passes through the slotted optical coupler 5102. The lead screw motor 2 591 is connected to the CBCT circuit board 61 through a cable. In the Y2 direction, the CBCT circuit board 61 gives a signal, the lead screw motor 2 591 rotates, the support seat 2 592 moves, and the lead sheet joint part 3 511 moves independently. According to the number of electrical signal pulses, the lead leaf closing piece 3 511 moves to the set position according to the corresponding number of steps, and the electrical signal changes direction, so that the lead leaf closing piece 3 511 moves to the farthest end, and the baffle 2 5115 passes through the notch of the slot-type optical coupler 5102, and the lead leaf is reset to the maximum in the Y2 direction.

[0050] As an embodiment of the present utility model, Figure 1 As shown, the housing portion is composed of a front cover 71, a housing portion 2, and a rear cover 73. The housing portion 2 is fixed to the bottom plate assembly 1 by pan head screws. The front cover 71 is fixed to the housing portion 2 by pan head screws, and the rear cover 73 is fixed to the housing portion 2 by pan head screws.

[0051] Through the personnel in this field, all the electrical components in this case are connected to their corresponding power supplies through wires, and a suitable controller should be selected according to the actual situation to meet the control requirements. The specific connection and control sequence should refer to the following working principle, and the electrical connection between the electrical components is completed in the order of working in sequence. The detailed connection means are well-known technologies in this field. The following mainly introduces the working principle and process, and no longer explains the electrical control.

[0052] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A beam limiter for CBCT, characterized in that: It comprises a bottom plate (12), on which a filtering part (2), a light shielding part (3), a main board part (5), and a circuit board part (6) are installed; The light-shielding portion (3) comprises a mounting plate (32) and a light-shielding tube assembly (31); the mounting plate (32) is fixedly mounted on the bottom plate (12) via a supporting copper column (33); the light-shielding tube assembly (31) is fixedly mounted on the mounting plate (32); the light-shielding tube assembly (31) is composed of two half tubes (311) riveted together; two protective plates (312) are fixedly arranged on the outer walls of the two half tubes (311); The main board part (5) comprises a second mounting plate (51), a first lead sheet joint (52), a second lead sheet joint (57), and a third lead sheet joint (511). The second mounting plate (51) is mounted on the bottom plate (12) via a double-through hexagonal stud (4). The first lead sheet joint (52) and the second lead sheet joint (57) are slidably arranged on one side surface of the second mounting plate (51) along the X direction. Two third lead sheet joints (511) are slidably arranged on the other side surface of the second mounting plate (51) along the Y direction. A lead sheet one (522) is installed in the first component (52), a lead sheet two (572) is installed in the second lead sheet joint component (57), a lead sheet three (5112) is installed in the third lead sheet joint component (511), a motor joint component one (53) for driving the movement of the first lead sheet joint component (52) is installed on one side of the first lead sheet joint component (52) on the second mounting plate (51), and a motor joint component two (59) for driving the movement of the second lead sheet joint component (57) and the two third lead sheet joint components (511) are installed on one side of the second mounting plate (51).

2. A beam limiter for CBCT according to claim 1, characterized in that: Linear guide rails (54) are arranged on both side surfaces of the second mounting plate (51), and the first lead sheet joint (52), the second lead sheet joint (57), and the two third lead sheet joints (511) are respectively mounted on the sliders of the linear guide rails (54).

3. A beam limiter for CBCT according to claim 2, characterized in that: The motor assembly (53) comprises a screw motor (531) and a support seat (532), wherein the support seat (532) is screwed onto the screw of the screw motor (531), and the screw motor (531) is fixedly mounted on the mounting plate (51) via the motor seat. The motor assembly (59) comprises a screw motor (591) and a support seat (592), wherein the support seat (592) is screwed onto the screw of the screw motor (591), and the screw motor (591) is fixedly mounted on the mounting plate (51) via the motor seat.

4. A beam limiter for CBCT according to claim 3, characterized in that: The lead sheet joint part 1 (52) and the lead sheet joint part 2 (57) have the same structure, and both include a lead sheet clamping plate 1 (521), a lead sheet pressure plate 1 (523), a connecting plate 1 (524), and a baffle 1 (525). The connecting plate 1 (524) is fixedly connected to the lead sheet clamping plate 1 (521) by pan head screws through the upper positioning holes of the lead sheet and the lead sheet pressure plate 1 (523). The baffle 1 (525) is fixedly connected to the lead sheet clamping plate 1 (521) by pan head screws through the lower positioning holes of the lead sheet and the lead sheet pressure plate 1 (523). The connecting plate 1 (524) and the Baffle 1 (525) is fixedly connected to the slider in the linear guide rail (54); the connecting plate 1 (524) in the lead sheet joint 1 (52) and the lead sheet joint 2 (57) are respectively connected to the support seat 1 (532) and the support seat 2 (592); an optical coupler 1 (56) is fixedly arranged on the mounting plate 2 (51) located on one side of the lead sheet joint 1 (52) and the lead sheet joint 2 (57); when the lead sheet joint 1 (52) or the lead sheet joint 2 (57) moves, the baffle 1 (525) can slide across the optical coupler 1 (56).

5. The beam limiter for CBCT according to claim 3, characterized in that: The lead sheet assembly part 3 (511) comprises a lead sheet clamping plate 2 (5111), a lead sheet 3 (5112), a lead sheet pressing plate 2 (5113), a connecting plate 2 (5114), and a baffle 2 (5115). The connecting plate 2 (5114) is fixed to the lead sheet clamping plate 2 (5111) by means of pan head screws through the upper end positioning holes of the lead sheet 3 (5112) and the lead sheet pressing plate 2 (5113). The baffle 2 (5115) is fixed to the lead sheet clamping plate 2 (5111) by means of pan head screws through the lower end positioning holes of the lead sheet 3 (5112) and the lead sheet pressing plate 2 (5113). The screws are fixedly connected to the lead sheet clamp plate 2 (5111), the connecting plate 2 (5114) and the baffle plate 2 (5115) are fixedly connected to the slider in the linear guide rail (54), the connecting plate 2 (5114) is connected to the support seat 2 (592), and the optical coupler 2 (510) is fixedly arranged on the mounting plate 2 (51) located on one side of the two lead sheet joints 3 (511), and when the lead sheet joint 3 (511) moves, the baffle plate 2 (5115) can slide over the optical coupler 2 (510).

6. The beam limiter for CBCT according to claim 1, characterized in that: The filtering part (2) comprises a filtering gear (211), a filter plate (212), a circular hole (214), and a stepping motor (221); a filtering shaft (13) is fixedly arranged on the bottom plate (12); the filtering gear (211) is rotatably mounted on the filtering shaft (13); the filter plate (212) is fixedly mounted on the filtering gear (211); a stepping motor (221) is fixedly arranged on one side of the filtering gear (211) on the bottom plate (12) via a filtering motor bracket (222); a driving gear (223) meshing with the filtering gear (211) is fixedly mounted on the driving end of the stepping motor (221).

7. The beam limiter for CBCT according to claim 6, characterized in that: A gear optical coupler (23) is fixedly arranged on the bottom plate (12), and a circular hole (214) is opened on the filtering gear (211). When the filtering gear (211) rotates, the circular hole (214) can pass through the notch of the gear optical coupler (23).

8. The beam limiter for CBCT according to claim 1, characterized in that: The circuit board portion (6) comprises a CBCT circuit board (61), an insulating spacer column (62), and a support plate (63); the CBCT circuit board (61) is fixed to the support plate (63) by means of pan head screws passing through the center holes of the insulating spacer columns (62); and the support plate (63) is fixedly connected to the base plate (12) by means of countersunk screws.

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