JP2024030865A - Signal transmitter and x-ray ct scanner - Google Patents

Abstract

To precisely transmit low-frequency signals without increasing the size of a device.SOLUTION: The signal transmitter according to an embodiment is a signal transmitter which transmits a signal to one of a rotation unit and a fixation unit to the other by contactless communication, and includes a ring-shaped housing, a first substrate, and a second substrate. The ring-shaped housing has a metal surface and an opening unit and is set in one of the rotation unit and the fixation unit. The first substrate is arranged in the opening unit and has a first transmission line for transmitting a signal output from a signal source and a reference potential conductor for providing a reference potential of the first transmission line. The second substrate is arranged in an end surface of the ring-shaped housing in a peripheral surface and has a second transmission line folded at the opening unit. The reference potential is on the metal surface. The first transmission line and the second transmission line are electrically connected together. The first substrate has a region in contact with the metal surface.SELECTED DRAWING: Figure 6C

Description

Embodiments disclosed in this specification and the drawings relate to a signal transmission device and an X-ray CT device.

2. Description of the Related Art Communication systems that perform wireless communication between adjacent devices using electromagnetic coupling are known. For example, a signal transmission device is known that performs data communication at high speed between a rotating frame and a fixed frame. Also, a device is known in which power is supplied to a ring-shaped transmission line using a line coupler.

However, in a device that supplies power to a transmission line using a line coupler, for example, when trying to transmit a signal in the baseband band, that is, when transmitting a low frequency signal, the wavelength becomes long, so the scale of the device becomes large. , requiring large space.

US Patent No. 7212077 US Patent No. 8,594,480

One of the problems to be solved by the embodiments disclosed in this specification and the drawings is to accurately transmit low frequency signals without increasing the scale of the device. However, the problems solved by the embodiments disclosed in this specification and the drawings are not limited to the above problems. Problems corresponding to the effects of each configuration shown in the embodiments described later can also be positioned as other problems.

The signal transmission device according to the present embodiment is a signal transmission device that transmits a signal from one of a rotating part and a fixed part to the other by non-contact communication, and includes a ring-shaped housing, a first substrate, a second substrate, and a ring-shaped housing. and a substrate. The ring-shaped housing has a metal surface and an opening, and is installed on one of the rotating part and the fixed part. The first substrate includes a first transmission line that is disposed in the opening and transmits a signal output from a signal source, and a reference potential conductor that provides a reference potential of the first transmission line. The second substrate is disposed on a circumferential end face of the ring-shaped housing, has a second transmission line bent at the opening, and has the metal surface as a reference potential. The first transmission line and the second transmission line are electrically connected. The first substrate has a region in contact with the metal surface.

FIG. 1 is a diagram showing an example of the configuration of an X-ray CT apparatus to which a communication system forming a signal transmission apparatus according to the present embodiment is applied. FIG. 2 is a diagram schematically showing a communication system that constitutes the signal transmission device according to this embodiment. FIG. 3 is a diagram illustrating an example of the configuration of a communication system that constitutes the signal transmission device according to the present embodiment. FIG. 4A is a diagram illustrating another example of the configuration of a communication system that constitutes the signal transmission device according to this embodiment. FIG. 4B is a plan view of the ring-shaped housing for five lanes when viewed near the power feeding section. FIG. 4C is a perspective view of the ring-shaped casing for three lanes seen near the power supply unit in the broken line region R of FIG. 4B. FIG. 5 is a perspective view of a configuration in which a rigid board is arranged in a ring-shaped housing for three lanes, as viewed near the power feeding section. FIG. 6A is a perspective view of the ring-shaped housing for one lane when viewed near the power feeding section. FIG. 6B is a perspective view of a configuration in which a rigid board is arranged in a ring-shaped housing for one lane, as viewed near the power feeding section. FIG. 6C is a perspective view of a configuration in which a rigid board and a flexible printed circuit board are arranged in a ring-shaped housing for one lane, when viewed near the power supply unit. FIG. 7A is a sectional view taken along the line A-A' in FIG. 6C. FIG. 7B is a sectional view taken along the line B-B' in FIG. 6C. FIG. 7C is a sectional view taken along the line C-C' in FIG. 6C. FIG. 7D is a sectional view taken along the line D-D' in FIG. 6C. FIG. 8A shows a configuration in which a rigid board and a flexible printed circuit board are arranged in a ring-shaped housing for one lane near the power supply part as the structure of this embodiment (simulation model of this embodiment) for executing a simulation. It is a perspective view when seen. Figure 8B shows a structure of a comparative example (simulation model of a comparative example) for executing a simulation, in which a rigid board and a flexible printed circuit board are arranged in a ring-shaped housing for one lane, as seen near the power supply section. FIG. FIG. 9A is a sectional view taken along the line E-E' in FIG. 8B. FIG. 9B is a sectional view taken along the line F-F' in FIG. 8B. FIG. 9C is a sectional view taken along the line GG' in FIG. 8B. FIG. 10A is a diagram showing electromagnetic field simulation results of input reflection characteristics by simulation models of the present embodiment and the comparative example, as simulation results of the structure of the present embodiment and the comparative example. FIG. 10B is a diagram showing electromagnetic field simulation results of input reflection characteristics by simulation models of the present embodiment and the comparative example, as simulation results of the structure of the present embodiment and the comparative example. FIG. 11A is a perspective view of a configuration in which a rigid board and a flexible printed circuit board are arranged in a ring-shaped housing for one lane, as seen near the power supply part, as a structure for explaining the difference in the position of the connection part. be. FIG. 11B is a sectional view taken along the line H-H' in FIG. 11A. FIG. 12 is an enlarged view of FIG. 7C (cross-sectional view taken along the line C-C' in FIG. 6C).

Hereinafter, embodiments of a signal transmission device and an X-ray CT device will be described in detail with reference to the drawings. Note that the embodiments are not limited to the following embodiments. Moreover, the content described in one embodiment is similarly applied to other embodiments in principle.

The communication system that constitutes the signal transmission device according to this embodiment is applied to, for example, an X-ray computed tomography (CT) device.

FIG. 1 is a diagram showing an example of the configuration of an X-ray CT apparatus 1 to which a communication system forming a signal transmission apparatus according to the present embodiment is applied. The X-ray CT apparatus 1 collects CT image data of a subject. Specifically, the X-ray CT apparatus 1 rotates the X-ray tube and the X-ray detector approximately around the subject, detects the X-rays that have passed through the subject, and collects projection data. Then, the X-ray CT apparatus 1 generates CT image data based on the collected projection data. As shown in FIG. 1, the X-ray CT apparatus 1 includes a gantry device 10, a bed device 30, and a console device 40.

In this embodiment, the rotation axis of the rotating frame 13 in a non-tilted state or the longitudinal direction of the top plate 33 of the bed device 30 is defined as the Z-axis direction. Further, the axial direction that is orthogonal to the Z-axis direction and horizontal to the floor surface is defined as the X-axis direction. Further, the axial direction that is orthogonal to the Z-axis direction and perpendicular to the floor surface is defined as the Y-axis direction. Note that FIG. 1 depicts the gantry apparatus 10 from multiple directions for explanation, and shows a case where the X-ray CT apparatus 1 has one gantry apparatus 10.

The gantry device 10 includes an X-ray tube 11, an X-ray detector 12, a rotating frame 13, an X-ray high voltage device 14, a control device 15, a wedge 16, a collimator 17, and a data acquisition system (Data Acquisition System). System: DAS) 18 and a fixed frame 19.

The X-ray tube 11 is a vacuum tube that has a cathode (filament) that generates thermoelectrons and an anode (target) that generates X-rays upon collision with the thermoelectrons. The X-ray tube 11 generates X-rays to irradiate the subject P by irradiating thermoelectrons from the cathode to the anode by applying a high voltage from the X-ray high voltage device 14 . For example, the X-ray tube 11 includes a rotating anode type X-ray tube that generates X-rays by irradiating a rotating anode with thermoelectrons.

The wedge 16 is a filter for adjusting the amount of X-rays irradiated from the X-ray tube 11. Specifically, the wedge 16 transmits and attenuates the X-rays emitted from the X-ray tube 11 so that the X-rays emitted from the X-ray tube 11 to the subject P have a predetermined distribution. This is a filter that For example, the wedge 16 is a wedge filter or a bow-tie filter, and is a filter made of aluminum or the like so as to have a predetermined target angle and a predetermined thickness.

The collimator 17 is a lead plate or the like for narrowing down the irradiation range of the X-rays that have passed through the wedge 16, and forms a slit by combining a plurality of lead plates or the like. Note that the collimator 17 is sometimes called an X-ray diaphragm. Further, although FIG. 1 shows a case where the wedge 16 is arranged between the X-ray tube 11 and the collimator 17, it is also a case where the collimator 17 is arranged between the X-ray tube 11 and the wedge 16. Good too. In this case, the wedge 16 transmits and attenuates the X-rays irradiated from the X-ray tube 11 and whose irradiation range is limited by the collimator 17.

The X-ray detector 12 has a plurality of detection elements that detect X-rays. Each detection element in the X-ray detector 12 detects the X-rays emitted from the X-ray tube 11 and passed through the subject P, and outputs a signal corresponding to the detected X-ray dose to the DAS 18. The X-ray detector 12 has, for example, a plurality of detection element rows in which a plurality of detection elements are arranged in a channel direction along one circular arc centered on the focal point of the X-ray tube 11. The X-ray detector 12 has, for example, a structure in which a plurality of detection element rows in which a plurality of detection elements are arranged in a channel direction are arranged in a column direction (slice direction, row direction).

For example, the X-ray detector 12 is an indirect conversion type detector that includes a grid, a scintillator array, and a photosensor array. A scintillator array has multiple scintillators. The scintillator has a scintillator crystal that outputs light with an amount of photons corresponding to the amount of incident X-rays. The grid is disposed on the X-ray incident side of the scintillator array and has an X-ray shielding plate that absorbs scattered X-rays. Note that the grid is sometimes called a collimator (one-dimensional collimator or two-dimensional collimator). The optical sensor array has a function of converting into an electrical signal according to the amount of light from the scintillator, and includes optical sensors such as photodiodes, for example. Note that the X-ray detector 12 may be a direct conversion type detector having a semiconductor element that converts incident X-rays into electrical signals.

The X-ray high voltage device 14 has electric circuits such as a transformer and a rectifier, and includes a high voltage generator that generates a high voltage to be applied to the X-ray tube 11 and an X-ray generator that generates a high voltage to be applied to the X-ray tube 11. and an X-ray control device that controls the output voltage according to the The high voltage generator may be of a transformer type or an inverter type. Note that the X-ray high voltage device 14 may be provided on the rotating frame 13 or the fixed frame 19. Here, the fixed frame 19 is a frame that rotatably supports the rotating frame 13 and has a rotation mechanism for rotating the rotating frame 13. The rotating frame 13 and the fixed frame 19 are examples of a rotating part and a fixed part, respectively.

The DAS 18 collects X-ray signals detected by each detection element included in the X-ray detector 12. For example, the DAS 18 includes an amplifier that performs amplification processing on the electrical signal output from each detection element and an A/D converter that converts the electrical signal into a digital signal, and generates detection data. DAS18 is realized by a processor, for example. DAS 18 is an example of a data collection device.

The rotating frame 13 is an annular frame that supports the X-ray tube 11 and the X-ray detector 12 facing each other, and allows the X-ray tube 11 and the X-ray detector 12 to be rotated by the control device 15. For example, the rotating frame 13 is cast from aluminum. Note that, in addition to the X-ray tube 11 and the X-ray detector 12, the rotating frame 13 can also support an X-ray high voltage device 14, a wedge 16, a collimator 17, a DAS 18, and the like. Furthermore, the rotating frame 13 may further support various configurations not shown in FIG.

The rotating frame 13 and the fixed frame 19, which is a non-rotating portion of the gantry device 10, are each provided with a signal transmission device. For example, data generated by the DAS 18 (collected X-ray signals) is transmitted from a signal transmission device provided on the rotating frame 13 to a signal transmission device provided on the fixed frame 19 by wireless communication, and then sent to the console device 40. will be forwarded to. Further, for example, a control signal for the rotating frame 13 transmitted by the console device 40 is transmitted from a signal transmitting device provided in the fixed frame 19 to a signal transmitting device provided in the rotating frame 13 by wireless communication. Note that the signal transmission device provided on the rotating frame 13 and the signal transmission device provided on the fixed frame 19 constitute a communication system 600, which will be described later.

The control device 15 includes a processing circuit including a CPU (Central Processing Unit), and a drive mechanism such as a motor and an actuator. The control device 15 receives input signals from the input interface 43 and controls the operations of the gantry device 10 and the bed device 30. For example, the control device 15 controls the rotation of the rotating frame 13, the tilt of the gantry device 10, the operation of the bed device 30 and the top plate 33, and the like. For example, as a control for tilting the gantry device 10, the control device 15 rotates the rotation frame 13 about an axis parallel to the X-axis direction based on input inclination angle (tilt angle) information. Note that the control device 15 may be provided on the gantry device 10 or may be provided on the console device 40.

The bed device 30 is a device on which a subject P to be photographed is placed and moved, and includes a base 31, a bed driving device 32, a top plate 33, and a support frame 34. The base 31 is a casing that supports the support frame 34 movably in the vertical direction. The bed driving device 32 is a drive mechanism that moves the top plate 33 on which the subject P is placed in the longitudinal direction of the top plate 33, and includes a motor, an actuator, and the like. The top plate 33 provided on the upper surface of the support frame 34 is a plate on which the subject P is placed. In addition to the top plate 33, the bed driving device 32 may move the support frame 34 in the longitudinal direction of the top plate 33.

The console device 40 has a memory 41, a display 42, an input interface 43, and a processing circuit 44. Although the console device 40 will be described as being separate from the gantry device 10, the gantry device 10 may include the console device 40 or a part of each component of the console device 40.

The memory 41 is realized by, for example, a RAM (Random Access Memory), a semiconductor memory element such as a flash memory, a hard disk, an optical disk, or the like. The memory 41 stores, for example, projection data and CT image data. Further, for example, the memory 41 stores a program for a circuit included in the X-ray CT apparatus 1 to realize its function. Note that the memory 41 may be realized by a server group (cloud) connected to the X-ray CT apparatus 1 via a network.

The display 42 displays various information. For example, the display 42 displays various images generated by the processing circuit 44 and displays a GUI (Graphical User Interface) for accepting various operations from an operator. For example, the display 42 is a liquid crystal display or a CRT (Cathode Ray Tube) display. Note that the display 42 may be provided on the gantry device 10. Further, the display 42 may be of a desktop type, or may be configured with a tablet terminal or the like that can communicate wirelessly with the console device 40 main body.

The input interface 43 receives various input operations from an operator, converts the received input operations into electrical signals, and outputs the electrical signals to the processing circuit 44 . For example, the input interface 43 receives input operations from the operator, such as reconstruction conditions when reconstructing CT image data and image processing conditions when generating post-processed images from CT image data. For example, the input interface 43 may include a mouse, a keyboard, a trackball, a switch, a button, a joystick, a touchpad that performs input operations by touching the operation surface, a touchscreen that integrates a display screen and a touchpad, and an optical sensor. This is realized by using a non-contact input circuit, a voice input circuit, etc. Note that the input interface 43 may be provided in the gantry device 10. Furthermore, the input interface 43 may be configured with a tablet terminal or the like that can communicate wirelessly with the main body of the console device 40. Furthermore, the input interface 43 is not limited to one that includes physical operation parts such as a mouse and a keyboard. For example, an electric signal processing circuit that receives an electric signal corresponding to an input operation from an external input device provided separately from the console device 40 and outputs this electric signal to the processing circuit 44 is also an example of the input interface 43. included.

The processing circuit 44 controls the overall operation of the X-ray CT apparatus 1 . For example, the processing circuit 44 executes a system control function 440, a scan control function 441, a preprocessing function 442, a reconstruction processing function 443, and a display control function 444.

The system control function 440 controls various functions of the processing circuit 44 based on input operations received from the operator via the input interface 43.

The scan control function 441 executes a scan of the subject P using X-rays. For example, the scan control function 441 controls scanning based on an input operation received from an operator via the input interface 43. Specifically, the scan control function 441 controls the output voltage from the high voltage generator by transmitting a control signal to the X-ray high voltage device 14 based on the input operation. The scan control function 441 also controls data collection by the DAS 18 by transmitting a control signal to the DAS 18 .

The preprocessing function 442 performs preprocessing on the X-ray detection data transmitted from the DAS 18 to generate preprocessed data. Specifically, the preprocessing function 442 generates preprocessed data by performing correction processes such as logarithmic conversion processing, offset correction, sensitivity correction, and beam hardening correction. Note that the data before preprocessing (X-ray detection data) and the data after preprocessing may be collectively referred to as projection data.

The reconstruction processing function 443 reconstructs the projection data generated by the preprocessing function 442 using various reconstruction methods (for example, a back projection method such as FBP (Filtered Back Projection), a successive approximation method, etc.). Generate CT image data. Furthermore, the reconstruction processing function 443 stores the generated CT image data in the memory 41.

The display control function 444 causes the display 42 to display various images generated by the processing circuit 44. For example, the display control function 444 causes the display 42 to display the CT image data generated by the reconstruction processing function 443.

In the X-ray CT apparatus 1 shown in FIG. 1, each processing function is stored in the memory 41 in the form of a program executable by a computer. The processing circuit 44 is a processor that reads programs from the memory 41 and executes them to implement functions corresponding to each program. In other words, the processing circuit 44 in a state where each program has been read has a function corresponding to the read program.

The word "processor" used in the above description means, for example, a circuit such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an Application Specific Integrated Circuit (ASIC). Furthermore, the word "processor" means a circuit such as a programmable logic device. Examples of the programmable logic device include a simple programmable logic device (SPLD) and a complex programmable logic device (CPLD). Further, as a programmable logic device, for example, a field programmable gate array (FPGA) can be mentioned. When the processor is, for example, a CPU, the processor realizes its functions by reading and executing a program stored in the memory 41. On the other hand, if the processor is, for example, an ASIC, instead of storing the program in the memory 41, the program is directly incorporated into the processor's circuitry. Note that each processor of this embodiment is not limited to being configured as a single circuit for each processor, but may also be configured as a single processor by combining multiple independent circuits to realize its functions. good. Furthermore, a plurality of components in FIG. 1 may be integrated into one processor to realize its functions.

Next, the principle of wireless communication of the communication system to which the signal transmission device according to the present embodiment is applied will be explained.

FIG. 2 is a diagram schematically showing a communication system that constitutes the signal transmission device according to this embodiment. As shown in FIG. 2, the communication system includes a transmitting side signal transmission device 100 and a receiving side signal transmission device 200.

The signal transmission device 100 on the transmitting side is configured to be long in one direction, and has a function as a transmitting coupler that transmits wireless signals. The signal transmission device 100 includes a set of transmission lines 101 for differential transmission, a signal source 102, a differential transmission buffer 103, a termination section 104 that is a termination resistor, a metal section 105, and a flexible printed circuit board 107. Equipped with

One set of transmission lines 101 for differential transmission is two linear conductor members arranged side by side, and is a transmission line on the transmission side that transmits a wireless signal. The transmission line 101 is formed as a pattern on the flexible printed circuit board 107. Data output from the signal source 102 is input as a differential signal via a differential transmission buffer 103 connected to one end of the transmission line 101. Here, the configuration of the signal source 102 and the differential transmission buffer 103 is explained as an example of the circuit configuration on the transmission side, but the configuration is not limited to the configuration shown in FIG. A power supply circuit, a distributor, various filters, and electronic components such as an amplifier and an attenuator may be installed. The other end of the transmission line 101 is terminated at a termination section 104 having an impedance substantially equal to the characteristic impedance of the transmission line 101 on the transmission side.

The metal portion 105 has a substantially U-shaped cross-sectional structure including a pair of sidewall portions and a bottom portion. The pair of side wall portions of the metal portion 105 function as a support portion that supports the flexible printed circuit board 107 by being in contact with the flat surface of the flexible printed circuit board 107 . The metal part 105 and the flexible printed circuit board 107 form a space surrounded by the pair of side walls and the bottom of the metal part 105 and the flexible printed circuit board 107. Note that the transmission line 101 has two conductor members arranged in parallel along the longitudinal direction, and the inner surface of the flexible printed circuit board 107 is connected to the metal part 105 to be grounded (reference potential). This constitutes a transmission line for dynamic transmission, a so-called differential microstrip line.

The signal transmission device 200 on the reception side is arranged at a distance from the signal transmission device 100 on the transmission side, and has a function as a reception coupler that receives wireless signals. The signal transmission device 200 includes a substrate 201, a differential coupler 202, and a receiving circuit 203.

The signal transmission device 200 on the reception side corresponds to an example of a device that communicates with the signal transmission device 100 on the transmission side. The differential coupler 202 (hereinafter simply referred to as coupler 202) is two linear conductor members arranged side by side, and is a transmission line on the receiving side that receives a wireless signal from the transmission line 101. The coupler 202 is formed as a pattern on the substrate 201. The coupler 202 is movable substantially parallel to the longitudinal direction of the transmission line 101 . At least a portion of the coupler 202 and the transmission line 101 are viewed from a direction perpendicular to the moving direction of the signal transmission device 200 on the receiving side and a direction perpendicular to the direction in which the two conductor members are adjacent to each other. They overlap. The signal output from the coupler 202 is detected as a received signal by the receiving circuit 203.

The signal output from the signal source 102 is a digital signal of "1" or "0". Here, when the input impedance of the receiving circuit 203 is low, the signal output from the coupler 202 becomes an edge signal that depends on rising and falling edges. In this case, by using a comparator with a hysteresis voltage in the receiving circuit 203, the original "1" or "0" signal can be demodulated from the edge signal. Further, when the input impedance of the receiving circuit 203 is high, a waveform similar to the signal waveform propagated to the transmission line 101 is output from the coupler 202. In this case, by using an amplifier or the like in the receiving circuit 203 to amplify the signal to a size that allows digital signal processing, wireless communication becomes possible.

Next, a configuration of a communication system 600 using the above-described principle will be described. Note that configurations similar to those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 3 is a diagram illustrating an example of the configuration of a communication system 600 that constitutes the signal transmission device according to the present embodiment. The communication system 600 includes a signal transmission device 300 on the transmission side and a signal transmission device 200 on the reception side.

The signal transmission device 300 on the transmitting side is configured in an annular shape and functions as a transmitting coupler (long coupler) that transmits a wireless signal. Here, the signal transmission device 300 corresponds to the signal transmission device 100 in FIG. 2.

The signal transmission device 300 on the transmitting side includes flexible printed circuit boards 301a and 301b, transmission lines 303a and 303b, a ring-shaped housing 304, and a substrate 305 on the input side. Transmission lines 303a and 303b are formed on flexible printed circuit boards 301a and 301b, respectively. Note that a plurality of transmission lines may be arranged so as to run parallel to the transmission line 303a and the transmission line 303b, and in this case, multi-channel signal transmission is possible. Here, each of the flexible printed circuit boards 301a and 301b corresponds to the flexible printed circuit board 107 in FIG. 2, and each of the transmission lines 303a and 303b corresponds to a set of transmission lines 101 for differential transmission in FIG. .

Further, the flexible printed circuit board 301a and the flexible printed circuit board 301b are formed so as to wrap the transmission line 303a and the transmission line 303b around the ring-shaped housing 304 in an annular manner. The ring-shaped housing 304 has a substantially U-shaped cross-sectional structure including a pair of side walls and a bottom. Here, the ring-shaped housing 304 corresponds to the metal part 105 in FIG.

As shown in FIG. 3, when communicating using the outer circumference side surface (outer circumferential surface) of the ring-shaped housing 304, flexible printing is used to form transmission lines 303a and 303b on the outer circumferential surface of the ring-shaped housing 304. Substrates 301a and 301b are arranged on the outer peripheral surface of the ring-shaped housing 304 along the circumferential direction. Note that a support member on the ring-shaped housing 304 is also formed on the outer peripheral surface of the ring-shaped housing 304, and the support member supports the flexible printed circuit board. Conversely, when communicating using the inner peripheral side surface (inner peripheral surface) of the ring-shaped housing 304, the transmission lines 303a and 303b are formed as a pattern on the inner peripheral surface of the ring-shaped housing 304.

Transmission lines 303a and 303b are formed along the longitudinal direction of flexible printed circuit boards 301a and 301b, respectively. The transmission line 303a and the transmission line 303b are arranged substantially linearly along the circumferential direction of the ring-shaped housing 304 without overlapping each other. Specifically, the transmission line 303a is arranged along approximately half the circumference (approximately 180°) of one of the entire circumferences of the ring-shaped case 304, and the transmission line 303b is arranged along the other half of the entire circumference of the ring-shaped case 304. It is arranged along approximately half the circumference (approximately 180°).

Further, one end (starting end) of the transmission lines 303a, 303b in the circumferential direction is connected to a power feeding section into which a signal is input, and the other end is terminated with terminating resistors 310a, 310b (terminating end), respectively. be done. The starting end and the ending end of the transmission lines 303a and 303b are arranged to face each other with the rotation axis O of the rotation mechanism 400 interposed therebetween. Here, a shield plate 320 for blocking interference signals is arranged between the terminating resistor 310a and the terminating resistor 310b. Each of the termination resistors 310a and 310b corresponds to the termination section 104 in FIG. 2.

With the arrangement shown in FIG. 3, the direction of the signal transmitted along the transmission line 303a and the direction of the signal transmitted along the transmission line 303b are opposite to each other. Note that the transmission lines 303a and 303b each have two conductor members arranged in parallel along the longitudinal direction, and the inner surface of the ring-shaped housing 304 is used as a ground (reference potential). The transmission line constitutes a so-called differential microstrip line.

The input-side substrate 305 is placed close to the power feeding portions of the transmission lines 303a and 303b. A differential amplifier and the like are mounted on the substrate 305 on the input side. Here, the differential amplifier corresponds to the differential transmission buffer 103 in FIG.

The signal transmission device 200 on the receiving side moves relatively along the circumferential direction of the transmission lines 303a, 303b while maintaining a constant distance from the transmission lines 303a, 303b of the signal transmission device 300 on the transmitting side. Since the signal transmission device 200 has the same configuration as the signal transmission device 200 in FIG. 2, detailed explanation will be omitted.

In this embodiment, the rotating part is connected to the signal transmission device 300 on the transmitting side, and the fixed part is connected to the signal transmitting device 200 on the receiving side. Therefore, since the signal transmission device 300 on the transmitting side is rotatable around the rotation axis O, the signal transmitting device 300 on the transmitting side and the signal transmitting device 200 on the receiving side perform communication while rotating relative to each other. be able to. Here, the signal transmission device 300 on the transmission side connected to the rotating section corresponds to the signal transmission device provided in the rotating frame 13 of the X-ray CT apparatus 1 in FIG. Further, the receiving side signal transmission device 200 connected to the fixed portion of the rotation mechanism 400 corresponds to the signal transmission device provided in the fixed frame 19 of the X-ray CT apparatus 1 in FIG.

Note that the rotating portion may be connected to the signal transmission device 200 on the receiving side, and the fixed portion of the rotating mechanism 400 may be connected to the signal transmission device 300 on the transmitting side. Further, the first rotating section is connected to the receiving side signal transmission device 200, the second rotating section is connected to the sending side signal transmission device 300, and the sending side signal transmission device 300 and the receiving side signal transmission device 200 may be independently rotatable around the rotation axis O.

Further, a shield plate may be placed between the end of the flexible printed circuit board 301a where the transmission line 303a is formed and the end of the flexible printed circuit board 301b where the transmission line 303b is formed.

Furthermore, in this embodiment, a transmission system with one channel has been described, but in a multi-channel transmission system, the transmission lines 303a and 303b are not approximately 180 degrees apart, but have an interval of 90 degrees or less than 90 degrees. Alternatively, a plurality of power feeding sections may be provided. Moreover, it is also possible to arrange a plurality of transmission lines so as to run parallel to the transmission lines 303a and 303b. Furthermore, in the above-described embodiments, the case where the signal transmission device 300 is the transmitting side and the signal transmitting device 200 is the receiving side has been described, but the present invention is not limited to this case. The transmission device 200 may be on the transmitting side. Furthermore, the signal transmission devices 200 and 300 may be able to transmit and receive signals.

Although the transmission line described above is an example of a differential microstrip line, it is not limited to this, and other types of differential transmission lines such as a differential coplanar line, a differential coplanar line with a ground, etc. It may be. Further, although the above-mentioned transmission line is a differential transmission line, the transmission line is not limited to this, and may not be differential as long as external noise and unnecessary radiation are not a problem.

The communication system that constitutes the signal transmission device according to this embodiment has been described above. With such a configuration, the signal transmission device according to this embodiment transmits low-frequency signals with high accuracy without increasing the device scale.

For example, when feeding power to a ring-shaped transmission line, if you are trying to transmit a signal in the baseband band, specifically if you are transmitting a low frequency signal, the wavelength becomes long, so the equipment scale becomes large. and requires a large amount of space. On the other hand, in the signal transmission device according to this embodiment, as shown in FIG. 3, a long coupler is used as the signal transmission device 300 on the transmitting side, so there is no need to increase the scale of the device. Therefore, the signal transmission device according to the present embodiment has the following configuration in order to accurately transmit a low frequency signal by optimizing the reflection characteristics.

Specifically, the signal transmission device according to the present embodiment is a signal transmission device that transmits a signal from one of a rotating part (rotating frame 13) and a fixed part (fixed frame 19) to the other by non-contact communication. , a ring-shaped housing, a first substrate, and a second substrate. The ring-shaped housing has a metal surface and an opening, and is installed on one of the rotating part and the fixed part. The first substrate has a first transmission line that is disposed in the opening and transmits the signal output from the signal source 102, and a reference potential conductor that provides a reference potential of the first transmission line. The second substrate is disposed on the circumferential end face of the ring-shaped housing, has a second transmission line bent at the opening, and has a metal surface as a reference potential. The first transmission line and the second transmission line are electrically connected. The first substrate has a region in contact with the metal surface.

Here, in the example shown in FIG. 3, the ring-shaped housing 304 is arranged at the rotating part. In this case, the signal source 102 is the DAS 18, and the signal output from the signal source 102 is an X-ray signal collected by the DAS 18.

First, the ring-shaped housing will be explained using FIGS. 4A to 4C and FIG. 6A.

FIG. 4A is a diagram illustrating another example of the configuration of a communication system 600 that constitutes the signal transmission device according to this embodiment. In the example shown in FIG. 4A, contrary to the example shown in FIG. 3, communication is performed using the inner peripheral surface of the ring-shaped housing 304. That is, in the example shown in FIG. 4A, the flexible print of the signal transmission device 300 on the transmission side is formed such that the transmission lines 303a and 303b of the signal transmission device 300 on the transmission side are formed as a pattern on the inner peripheral surface of the ring-shaped housing 304. Substrates 301a and 301b are arranged on the inner peripheral surface of the ring-shaped housing 304 along the circumferential direction. Hereinafter, a case where communication is performed using the inner peripheral surface of the ring-shaped housing 304 will be described as an example.

4B and 4C are enlarged views showing an example of the configuration of the ring-shaped housing 304 near the power feeding section. FIG. 4B is a plan view of the ring-shaped housing 304 for five lanes when viewed near the power feeding section. Here, FIG. 4C is a perspective view of the ring-shaped casing 304 for three lanes seen near the power feeding section in the broken line region R of FIG. 4B. As shown in FIGS. 4B and 4C, the ring-shaped casing 304 has a plurality of ring-shaped walls arranged at intervals in the axial direction, and the walls have divided regions divided in the circumferential direction. have The ring-shaped housing 304 has a metal surface and an opening, and the opening is formed by arranging a plurality of walls so that the divided regions are at the same position in the circumferential direction.

FIG. 6A is a perspective view of the ring-shaped housing 304 for one lane when viewed near the power feeding section. As shown in FIG. 6A, the ring-shaped housing 304 includes a base body 304A that is a metal member, support members 304B and 304C that constitute metal surfaces on the base body 304A, and an opening 304D. The support members 304B and 304C are wall portions and correspond to a pair of side wall portions of the metal portion 105. Further, the base body 304A corresponds to the bottom of the metal portion 105. The opening 304D shown in FIGS. 4B, 4C, and 6A is formed by the support members 304B, 304C, and the region where the base body 304A is divided.

Next, the first substrate will be explained using FIG. 5, FIG. 6B, FIG. 6C, FIG. 7A, and FIG. 7B.

FIG. 5 is a perspective view of a configuration in which the rigid board 111 is arranged in the ring-shaped housing 304 for three lanes, as seen near the power supply section. FIG. 6B is a perspective view of a configuration in which the rigid board 111 is arranged in the ring-shaped housing 304 for one lane, as seen near the power feeding section. FIG. 6C is a perspective view of a configuration in which the rigid board 111 and the flexible printed circuit board 107 are arranged in the ring-shaped housing 304 for one lane, when viewed near the power supply section. Here, FIG. 7A is a sectional view taken along the line A-A' in FIG. 6C. FIG. 7B is a sectional view taken along the line B-B' in FIG. 6C. The rigid substrate 111 is an example of a first substrate.

As shown in FIGS. 5, 6B, and 6C, the rigid substrate 111 is arranged approximately in the normal direction to the ring-shaped housing 304. As shown in FIG. 6B, the rigid substrate 111 has transmission lines 111a and 111b that are arranged in the opening 304D and transmit the signal output from the signal source 102. Further, as shown in FIGS. 5, 6B, and 7A, the rigid substrate 111 has a GND wiring 121 that provides a reference potential for the transmission lines 111a and 111b. The transmission lines 111a and 111b are examples of first transmission lines, and the GND wiring 121 is an example of a reference potential conductor.

As shown in FIG. 7A, the rigid board 111 has two main surfaces 111-1 and 111-2, and two side surfaces 111-3 and 111-4 that connect the two main surfaces 111-1 and 111-2. has. The two side surfaces 111-3 and 111-4 are parallel to the signal transmission direction. The transmission lines 111a and 111b are arranged on one main surface 111-1 of the two main surfaces 111-1 and 111-2, and the GND wiring 121 is arranged on the other main surface 111-1 of the two main surfaces 111-1 and 111-2. It is placed on the surface 111-2.

Here, as shown in FIGS. 6B and 6C, the rigid substrate 111 has a region R1 in contact with the support members 304B and 304C, which are metal surfaces. Specifically, the rigid substrate 111 has a region R1 sandwiched between two adjacent wall portions (support members 304B, 304C). For example, as shown in FIG. 7B, in region R1, two side surfaces 111-3 and 111-4 are in contact with support members 304B and 304C, respectively. Note that the GND wiring 121 is also formed up to the region between two adjacent wall portions (supporting members 304B, 304C).

Next, the second substrate will be explained using FIG. 6C, FIG. 7C, and FIG. 7D.

As described above, FIG. 6C is a perspective view of the structure in which the rigid board 111 and the flexible printed circuit board 107 are arranged in the ring-shaped housing 304 for one lane, as seen near the power supply section. Here, FIG. 7C is a sectional view taken along the line C-C' in FIG. 6C. FIG. 7D is a sectional view taken along the line D-D' in FIG. 6C. The flexible printed circuit board 107 is an example of a second board.

As shown in FIG. 6C, the flexible printed circuit board 107 is arranged on the circumferential end surface of the ring-shaped housing 304, has transmission lines 101a and 101b bent at an opening 304D, and has metal surfaces (supporting member 304B, 304C) as the reference potential. The flexible printed circuit board 107 corresponds to the flexible printed circuit board 107 in FIG. 2 and the flexible printed circuit boards 301a and 301b in FIG. 3. The transmission lines 101a and 101b correspond to the set of transmission lines 101 for differential transmission in FIG. 2 and the transmission lines 303a and 303b in FIG. 3. Furthermore, the transmission lines 101a and 101b are examples of second transmission lines.

As shown in FIGS. 6C and 7D, the support members 304B and 304C are members for supporting the flexible printed circuit board 107. The characteristic impedance of the transmission lines 101a and 101b of the flexible printed circuit board 107 is determined using the ring-shaped housing 304 as a reference potential (ground). The other ends of the transmission lines 101a and 101b are terminated at termination portions (terminal resistors 310a and 310b in FIG. 3) having an impedance substantially equal to the characteristic impedance. Further, the transmission lines 101a and 101b are optimized to obtain the electric field coupling necessary for wireless communication.

As shown in FIGS. 6C and 7C, the transmission lines 111a and 111b of the rigid board 111 and the transmission lines 101a and 101b of the flexible printed circuit board 107 are electrically connected. Specifically, as shown in FIG. 6C, the transmission lines 111a and 111b and the transmission lines 101a and 101b have a connecting portion R2 that is electrically connected on the rigid substrate 111. The connection portion R2 corresponds to a power feeding portion. The connection portion R2 is located at or near the region R1 where the rigid substrate 111 contacts the support members 304B and 304C. The vicinity of region R1 refers to a position downstream of region R1 in the signal transmission direction.

For example, as shown in FIG. 6C, the flexible printed circuit board 107 is supported by the radial end faces of two adjacent walls (supporting members 304B and 304C), so that the flexible printed circuit board 107 is supported along the circumferential direction of the ring-shaped housing 304. Further, the support members 304B and 304C are bent in the radial direction at the separated positions. As a result, the transmission lines 101a and 101b of the flexible printed circuit board 107 have an extending portion 110a extending in a direction (radial direction) different from the longitudinal direction (circumferential direction) of the transmission lines 101a and 101b at the connection portion R2, 110b. At the connection portion R2, the transmission lines 111a and 111b and the extension portions 110a and 110b are electrically connected on the rigid substrate 111.

Further, as shown in FIG. 6C, the line width of the transmission lines 101a and 101b formed in the circumferential direction of the ring-shaped housing 304 and the line width of the transmission line (extending parts 110a and 110b) formed in the connecting part R2 Different from width. When connecting transmission lines with different line widths, there is a possibility that the signal input at the connection part R2 will be reflected and the communication quality will deteriorate. Therefore, the line widths of the extensions 110a and 110b are set to be approximately equal to the line widths of the transmission lines 111a and 111b of the rigid board 111. Note that the transmission lines 111a and 111b formed on the rigid substrate 111 are designed so that their reflection characteristics are optimized.

In this embodiment, the structure shown in FIGS. 4B, 4C, 5, 6A to 6C, and 7A to 7D allows the reference potential to gradually shift from the GND wiring 121 on the rigid board 111 to the ring-shaped housing 304. Transition to. That is, in the structure of the present embodiment, since the rigid substrate 111 has the region R1 in contact with the metal surface (supporting members 304B and 304C of the ring-shaped housing 304), the reference potential is lowered as shown in FIGS. 7A to 7D. smoothly transitions from the GND wiring 121 on the rigid board 111 to the ring-shaped housing 304.

In the cross section shown in FIG. 7A, the transmission lines 111a and 111b of the rigid substrate 111 have the GND wiring 121 of the rigid substrate 111 as a reference potential.

In the cross section shown in FIG. 7B, the ring support members 304B and 304C extend to the surface layer of the rigid substrate 111. Therefore, the transmission lines 111a and 111b of the rigid board 111 have both the GND wiring 121 of the rigid board 111 and the ring-shaped housing 304 as reference potentials.

In the cross section shown in FIG. 7C, the transmission lines 111a and 111b of the rigid board 111 and the transmission lines 101a and 101b of the flexible printed circuit board 107 are based on both the GND wiring 121 of the rigid board 111 and the ring-shaped housing 304. It is set as electric potential.

In the cross section shown in FIG. 7D, the transmission lines 101a and 101b of the flexible printed circuit board 107 have the ring-shaped housing 304 as a reference potential.

As described above, in the structure of the present embodiment, since the rigid substrate 111 has the region R1 in contact with the metal surface (the supporting members 304B and 304C of the ring-shaped housing 304), the reference potential is adjusted to the GND wiring on the rigid substrate 111. 121 to the ring-shaped housing 304 smoothly. Therefore, with the structure of this embodiment, it is possible to reduce the amount of reflection and loss between transmission lines having different reference potentials.

The reason for this will be explained using this embodiment and a comparative example.

FIG. 8A shows a power supply configuration in which a rigid board 111 and a flexible printed circuit board 107 are arranged in a ring-shaped housing 304 for one lane, as a structure of this embodiment (simulation model of this embodiment) for executing a simulation. FIG. Here, the cross-sectional view taken along the line AA', the cross-sectional view taken along the line B-B', the cross-sectional view taken along the line CC', and the cross-sectional view taken along the line D-D' in FIG. 8A are respectively shown in FIGS. This is the same as the cross-sectional view shown in FIG.

As described above, in the structure of the present embodiment, the rigid substrate 111 has the region R1 in contact with the metal surface (the supporting members 304B, 304C of the ring-shaped housing 304), so that the reference potential is equal to the GND on the rigid substrate 111. There is a smooth transition from the wiring 121 to the ring-shaped housing 304.

FIG. 8B shows a configuration in which a rigid board 1111 and a flexible printed circuit board 1107 are arranged in a ring-shaped housing 1304 for one lane near the power supply part as a structure of a comparative example (simulation model of a comparative example) for executing a simulation. FIG. 9A to 9C are a cross-sectional view along the line E-E', a cross-sectional view along the line F-F', and a cross-sectional view along the line G-G' in FIG. 8B, respectively.

In the structure of the comparative example, the rigid substrate 1111 does not have a region in contact with the metal surface (support members 1304B and 1304C of the ring-shaped housing 1304). Therefore, in the structure of the comparative example, in the cross section shown in FIG. 9A, the transmission lines 1111a and 1111b of the rigid board 1111 operate with the GND wiring 1121 of the rigid board 1111 as a reference potential, and also in the cross section shown in FIG. 9B, As in the case of FIG. 9A, the transmission lines 1111a and 1111b of the rigid board 1111 operate with the GND wiring 1121 of the rigid board 1111 as a reference potential. However, in the cross section shown in FIG. 9B, the ring support members 1304B and 1304C do not extend to the surface of the rigid board 1111, so the transmission lines 1111a and 1111b of the rigid board 1111 are connected to the ring-shaped housing 304 (ring support member 304B). , 304C) is not used as the reference potential. In the cross section shown in FIG. 9C, the transmission lines 1101a and 1101b of the flexible printed circuit board 1107 operate with the ring-shaped housing 1304 (ring support members 304B and 304C) as a reference potential. In this way, in the structure of the comparative example, since the rigid board 1111 does not have a region in contact with the metal surface, the reference potential does not smoothly transition from the GND wiring 1121 on the rigid board 1111 to the ring-shaped housing 1304. .

10A and 10B are diagrams showing electromagnetic field simulation results of input reflection characteristics by simulation models of the present embodiment and the comparative example, as simulation results of the structure of the present embodiment and the comparative example.

In FIG. 10A, the solid line is the result of analysis using the simulation model of this embodiment, and the broken line is the result of analysis using the simulation model of the comparative example. In FIG. 10A, the horizontal axis shows the frequency, and the vertical axis shows the differential input reflection amount. The smaller the amount of reflection, the better the communication quality. In FIG. 10A, in the frequency range of 6 GHz or less, both models have -20 dB or less, but it can be seen that the amount of reflection is particularly smaller in the simulation model of this embodiment than in the simulation model of the comparative example. . From the viewpoint of error rate, it is required that the reflection be as small as possible, which shows the superiority of this embodiment.

Further, FIG. 10B is a diagram showing electromagnetic field simulation results of transfer characteristics. Similar to FIG. 10A, the solid line is the result of analysis using the simulation model of this embodiment, and the broken line is the result of analysis using the simulation model of the comparative example. In FIG. 10B, the horizontal axis represents frequency, and the vertical axis represents differential transmission amount. In FIG. 10B, it can be seen that the simulation model of this embodiment has a smaller amount of reflection, so that the signal is transmitted to the transmitting coupler without loss.

As described above, in the structure of the present embodiment, it is possible to suppress the influence on communication due to reflection from low frequencies based on the reflection characteristics and transfer characteristics, and to suppress a decrease in communication accuracy.

In addition, in the structure of this embodiment, by having the connection portion R2 where the transmission lines 111a, 111b and the transmission lines 101a, 101b are electrically connected on the rigid board 111, differential impedance is established as follows. It is also possible to suppress the effects of

FIG. 11A shows a structure in which a rigid board 111 and a flexible printed circuit board 107 are arranged in a ring-shaped housing 304 for one lane when viewed near the power supply part, as a structure for explaining the difference in the position of the connection part. FIG. FIG. 11B is a sectional view taken along the line H-H' in FIG. 11A. In the example shown in FIGS. 11A and 11B, transmission lines 111a and 111b and transmission lines 101a and 101b are electrically connected on flexible printed circuit board 107.

As shown in FIG. 11B, the transmission lines 101a and 101b of the flexible printed circuit board 107 arranged on the ring-shaped housing 304 communicate with the signal transmission device 200 on the receiving side by electric field coupling, so the transmission line width and The distance between transmission line widths is set. In the case of differential transmission lines, if electromagnetic fields generated from electronic devices in the environment interlink between the differential transmission lines, the differential circuit cannot cancel them, resulting in a decrease in communication performance. Therefore, the spacing between the differential transmission lines is set relatively small. Therefore, as shown in FIG. 11B, when the flexible printed circuit board 107 is connected to the rigid board 111 using an electrical connection member such as solder or an anisotropic conductive film (ACF), the connection member , the distance between the differential transmission lines is shortened, and impedance disturbances are more likely to occur. In addition, when connecting to the rigid board 111 on the flexible printed circuit board 107, the thickness at the connection part is different from that of other transmission line parts, so the gap with the signal transmission device 200 on the receiving side may be shortened at the connection part. is high. In communication using electric field coupling, the signal level changes depending on the distance between the transmitting and receiving couplers, which can be a factor that reduces communication performance.

FIG. 12 is an enlarged view of FIG. 7C (cross-sectional view taken along the line C-C' in FIG. 6C). In the example shown in FIG. 12, transmission lines 111a and 111b and transmission lines 101a and 101b are electrically connected on rigid substrate 111 in this embodiment.

As shown in FIG. 12, in the rigid substrate 111, transmission signals from differential transmission buffers and amplifiers are transmitted through transmission lines 111a and 111b. Alternatively, a differential transmission buffer and an amplifier are directly mounted on the rigid substrate 111, and the signal is transmitted through the transmission lines 111a and 111b. Here, the transmission lines 111a and 111b are designed as transmission lines that match the output impedance of a coaxial connector or an amplifier, so most of them are transmission lines with a characteristic impedance of 50Ω. Therefore, the distance between the transmission line 111a and the transmission line 111b does not need to be close, and can be designed independently. In other words, the distance between the transmission lines 111a and 111b of the rigid board 111 is wider than the distance between the transmission lines 101a and 101b of the flexible printed circuit board 107. Therefore, when transmission lines are connected to each other on the rigid substrate 111, the influence of connection members such as solder on differential impedance is almost eliminated, so that the influence on communication can be reduced. Furthermore, since the transmission lines 111a, 111b and the transmission lines 101a, 101b are connected on the rigid board 111, the thickness of the connection part R2 may affect the change in the gap with the signal transmission device 200 on the receiving side. It disappears.

In this way, the structure of this embodiment can also suppress the influence on differential impedance.

Note that in the above-described embodiment, the case is assumed in which the ring-shaped housing 304 is placed in the rotating part, the signal source 102 is the DAS 18, and the signal output from the signal source 102 is an X-ray signal collected by the DAS 18. Although the explanation has been given as an example, the invention is not limited to this.

For example, the ring-shaped housing 304 is placed on the fixed part. In this case, the signal source 102 is the console device 40 of the X-ray CT apparatus 1, and the signal output from the signal source 102 is a control signal for the rotating part (rotating frame 13) transmitted by the console device 40.

Alternatively, the ring-shaped housing 304 includes a first ring-shaped housing disposed on the rotating part and a second ring-shaped housing disposed on the fixed part. In this case, in the first ring-shaped housing, the signal source 102 is the DAS 18, and the signal output from the signal source 102 is an X-ray signal collected by the DAS 18. In the second ring-shaped housing, the signal source 102 is the console device 40 of the X-ray CT apparatus 1, and the signal output from the signal source 102 is a control signal for the rotating section transmitted by the console device 40.

Further, in the above-described embodiments, the case where the application is applied to an X-ray CT apparatus was explained as an example, but for example, an application that includes a rotating part and a fixed part and requires large-capacity (multi-channel) communication If so, it is not limited to an X-ray CT apparatus. For example, the embodiments described above can also be applied to network cameras, on-hand cameras of robots, and the like.

According to at least one embodiment described above, low frequency signals can be transmitted with high precision without increasing the scale of the device.

Although several embodiments have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, changes, and combinations of embodiments can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

100, 200, 300 signal transmission device 101a, 101b transmission line 107 flexible printed circuit board 111 rigid board 111a, 111b transmission line 304 ring-shaped housing 304B, 304C support member 304D opening

Claims (13)

A signal transmission device that transmits a signal from one of a rotating part and a fixed part to the other by non-contact communication,
a ring-shaped housing having a metal surface and an opening and installed on one of the rotating part and the fixed part;
a first substrate having a first transmission line disposed in the opening and transmitting a signal output from a signal source; and a reference potential conductor providing a reference potential of the first transmission line;
a second substrate disposed on a circumferential end surface of the ring-shaped housing, having a second transmission line bent at the opening, and having the metal surface as a reference potential;
Equipped with
the first transmission line and the second transmission line are electrically connected,
the first substrate has a region in contact with the metal surface;
Signal transmission equipment. The ring-shaped housing has a plurality of ring-shaped walls that constitute the metal surface and are arranged at intervals in the axial direction,
The wall portion has a divided region divided in the circumferential direction,
The opening is formed by arranging a plurality of the walls so that the divided regions are at the same position in the circumferential direction,
The second substrate is disposed along the circumferential direction by being supported by the radial end faces of the two adjacent wall portions, and is further bent in the radial direction at a position where the wall portions are separated,
The first substrate has, as the region, a region sandwiched between two adjacent wall portions,
The signal transmission device according to claim 1. The first substrate has two main surfaces and two side surfaces connecting the two main surfaces,
The first transmission line is arranged on one of the two main surfaces,
The reference potential conductor is arranged on the other of the two main surfaces,
In the region, each of the two side surfaces contacts each of the two adjacent wall portions,
The signal transmission device according to claim 2. The first transmission line and the second transmission line have a connection part that is electrically connected on the first substrate,
The signal transmission device according to claim 1. The connecting portion is located in the area or near the area,
The signal transmission device according to claim 4. In the second transmission line, the line width of the transmission line formed in the circumferential direction of the ring-shaped housing is different from the line width of the transmission line formed in the connection part,
The signal transmission device according to claim 4. The line width of the transmission line formed in the connection part is set to be equal to the line width of the first transmission line,
The signal transmission device according to claim 6. The first substrate is arranged in a direction substantially normal to the ring-shaped casing.
The signal transmission device according to claim 1. The rotating section includes an X-ray tube, an X-ray detector that detects X-rays emitted from the X-ray tube, and a data acquisition device that collects signals of the X-rays detected by the X-ray detector. death,
The fixed part has a rotation mechanism for rotating the rotating part,
The signal transmission device according to claim 1. The ring-shaped housing is arranged in the rotating part,
the signal source is the data collection device,
The signal is an X-ray signal collected by the data collection device,
The signal transmission device according to claim 9. The ring-shaped housing is arranged on the fixed part,
The signal source is a console device of an X-ray CT device,
The signal is a control signal for the rotating section transmitted by the console device,
The signal transmission device according to claim 9. The ring-shaped casing includes a first ring-shaped casing arranged in the rotating part and a second ring-shaped casing arranged in the fixed part,
In the first ring-shaped housing,
the signal source is the data collection device,
The signal is an X-ray signal collected by the data collection device,
In the second ring-shaped housing,
The signal source is a console device of an X-ray CT device,
The signal is a control signal for the rotating section transmitted by the console device,
The signal transmission device according to claim 9. a rotating part having an X-ray tube, an X-ray detector that detects X-rays emitted from the X-ray tube, and a data acquisition device that collects signals of the X-rays detected by the X-ray detector;
a fixed part having a rotation mechanism for rotating the rotating part;
a ring-shaped housing having a metal surface and an opening and installed on one of the rotating part and the fixed part;
a first substrate having a first transmission line disposed in the opening and transmitting a signal output from a signal source; and a reference potential conductor providing a reference potential of the first transmission line;
a second substrate disposed on a circumferential end surface of the ring-shaped housing, having a second transmission line bent at the opening, and having the metal surface as a reference potential;
Equipped with
the first transmission line and the second transmission line are electrically connected,
the first substrate has a region in contact with the metal surface;
X-ray CT device.

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