JPH06261003A - Data transmission equipment - Google Patents

Abstract

PURPOSE:To send lots of data with a simple configuration and excellent reliability and to facilitate the maintenance. CONSTITUTION:Plural light emitting elements 12 and light receiving elements 17 are provided extending over the entire part of a rotor 10, and each one light receiving element 15 and light emitting element 19 are provided to a part of a stator 11 with respect to the rotor 10. Thus, the maintenance is easily executed by removing part of the stator 11, that is, the part to which the light receiving element 15 and the light emitting element 19 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for transmitting data between two members whose positions are relatively changed, for example, between a rotating part and a fixed part in a gantry of an X-ray CT scanner. The present invention relates to a data transmission device that transmits data.

[0002]

2. Description of the Related Art Generally, in an X-ray CT scanner, a slip ring is used to exchange data between a rotating part and a fixed part in a gantry. That is, a conductive metal is arranged in a ring shape on the rotating part side, and a brush made of a conductive material is also arranged on the fixed part side. Regardless of whether the rotating part is rotated or stopped, the brush is always attached to the ring. Configured to touch. The contact between the brush and the ring realizes an electrical connection between the rotating portion and the fixed portion, so that data can be exchanged between the rotating portion and the fixed portion even during rotation.

However, in such a slip ring system, since the brush is always in mechanical contact with the ring,
The mechanical wear of both is inevitable. Therefore, it is necessary to perform regular maintenance, which is troublesome.

Data transmission may be momentarily stopped (temporarily interrupted) due to poor contact between the ring and the brush or contact resistance, and there are problems in reliability and data transmission quality. Furthermore, since the amount of data that can be transmitted depends on the number of rings and the transmission capacity (rate) between the ring and the brush,
There is a limit in rate, and it is necessary to increase the number of rings in order to increase the transmission amount beyond that, and there is a drawback that the mechanism becomes large.

There is also a data transmission device for bidirectionally transmitting data between a rotating part and a fixed part of an X-ray CT scanner. FIG. 16 is a configuration diagram of such an apparatus. A plurality of light emitting elements 2 are arranged on the inner circumference side of the ring-shaped rotating section 1 and a light receiving element is provided at a predetermined position on the outer circumference side thereof. 3-1 and 3-2 are arranged.

A plurality of light emitting elements 5 are arranged on the outer peripheral side of the ring-shaped fixing portion 4, and light receiving elements 6-1 and 6-2 are arranged at predetermined positions on the inner peripheral side thereof. Has been done.

With such a structure, the rotating part 1 is fixed to the fixed part 4
The mutual position is changed by rotating with respect to each other, and in this state, data is transmitted between the light emitting element 2 and each of the light receiving elements 6-1 and 6-2 through light, and the light emitting element 5 Data is transmitted between the light receiving elements 3-1 and 3-2 through light.

However, in such a device, since the rotating portion 1 and the fixed portion 4 are arranged so as to face each other, maintenance cannot be performed unless either the rotating portion 1 or the fixed portion 4 is removed at the time of maintenance. There is a problem.

[0009]

With the bidirectional data transmission structure as described above, maintenance cannot be performed unless, for example, either the rotating unit 1 or the fixed unit 4 of the X-ray CT scanner is removed. Therefore, an object of the present invention is to provide a data transmission device which can easily transmit a large amount of data with a simple structure and can be easily maintained.

[0010]

According to a first aspect of the present invention, there is provided a data transmission device for bidirectionally transmitting data between a first member and a second member, the positions of which relatively change.
A plurality of first optical transmitting / receiving elements provided over the entire member and at least one portion provided on the second or first member and transmitting / receiving data to / from each of the first optical transmitting / receiving elements via light. And a second optical transmission / reception element to achieve the above object.

According to a second aspect of the present invention, in the data transmission device for bidirectionally transmitting data between the first and second members whose relative positions change periodically, the data transmission device is provided on the first or second member. A plurality of optical transmission / reception element groups driven according to a plurality of data, and at least one which is provided on the second or first member and transmits / receives data to / from the optical transmission / reception element group via light.
A plurality of optical transmission / reception elements are provided so that predetermined transmission data is transmitted / received between the one optical transmission / reception element and the predetermined optical transmission / reception elements irrespective of changes in the relative positions of the first and second members. And a means for switching the transmission data in each cycle of the change in the relative position of the first and second members, thereby achieving the above object.

According to the third aspect, the first member formed in the ring shape, the arc-shaped second member moving on the circumference of the first member, and the first member on the circumference of the first member. A plurality of first optical transmitter-receiver elements provided over the second member,
A data transmission device, which comprises at least one second optical transmission / reception element that transmits / receives data to / from each first optical transmission / reception element, to achieve the above object.

According to a fourth aspect of the present invention, a ring-shaped first member, an arc-shaped second member that periodically moves on the circumference of the first member, and a circle of the first member. At least one second optical transceiver for transmitting and receiving data to and from the plurality of first optical transceiver elements provided along the circumference and the first optical transceiver element group provided on the second member. Element,
A plurality of transmission data supplied to each optical transmission / reception element is transmitted so that predetermined transmission data is transmitted / received to / from each predetermined optical transmission / reception element irrespective of a change in relative position of the first and second members. , And a means for switching in each cycle of the change of the relative position of the second member, which is a data transmission apparatus for achieving the above object.

[0014]

According to the present invention, a plurality of first optical transmitting / receiving elements are provided over the entire first or second member, and the position of the first optical transmitting / receiving element changes relative to the first or second member. The second optical transmitting / receiving element is provided on a part of the second or first member. Accordingly, maintenance work can be easily performed by removing a part of the second optical transmitting / receiving element of the second or first member.

According to the second aspect of the present invention, even in the case of a device for bidirectionally transmitting data between the first and second members whose relative positions change periodically, the entire first or second member. Since the plurality of first optical transmitter / receiver elements are provided over the second optical transmitter / receiver element and the second optical transmitter / receiver element is provided in a part of the second or first member, the maintenance work is performed in the second or a part of the second member. This can be easily done by removing the optical transceiver element.

According to a third aspect of the invention, a plurality of arc-shaped second members that move on the circumference of the ring-shaped first member are provided over the circumference of the first member. Since the second optical transmitting / receiving element for transmitting / receiving data to / from the first optical transmitting / receiving element of
This can be easily done by removing the arc-shaped second member.

Further, according to claim 4, even in the device for bidirectionally transmitting data between the first and second members whose relative positions change periodically, the arc-shaped second member is removed. This can be done easily.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

Here, for convenience of explanation, an embodiment used for transmitting a control signal, an X-ray detection signal and the like between the rotating portion and the fixed portion of the X-ray CT scanner will be described. But,
INDUSTRIAL APPLICABILITY The present invention can be applied to any data transmission device that transmits data between first and second members whose positions change relatively.

FIG. 1 is a block diagram of a data transmission device applied to an X-ray CT scanner, and is a view of the gantry portion of the CT scanner as seen from the front. A rotary unit 10 including an X-ray tube, a detector, etc. (not shown) is inserted into a hole provided at the center of the fixed unit 11 and rotatably held with respect to the fixed unit 11.

The axis of rotation of the rotating section 10 is in a direction orthogonal to the plane of FIG. Although not shown, the rotating unit 10
Has a donut-shaped housing, and the subject is placed in the center space so that the body axis of the subject coincides with the rotation axis.

A large number of light emitting elements (for example, light emitting diodes) 121, 122, ... 12n are arranged at regular intervals on the outer peripheral surface (opposing the fixed portion 11) of the housing of the rotating portion 10. These light emitting diodes 121, 122, ...
12n emits infrared light so that data transmission is not affected by natural light.

These light emitting elements 121, 122, ... 12n
Are uniformly driven by the driver 13 provided in the rotating unit 10 according to the transmission data 14, and transmit the same data via light. The number n of each light emitting element is determined according to the outer peripheral length of the housing of the rotating portion 10 and the distance d between the outer peripheral surface of the rotating portion housing and the wall surface of the hole of the fixed portion 11, as described later. .

A fixed portion 11 facing the outer peripheral surface of the rotating portion 10.
The light emitting elements 121, 122, ...
One light receiving element (for example, a photodiode) 15 that receives light from n is provided.

The output of the light receiving element 15 is supplied to the receiving section 16 provided in the fixed section 11 and detected as received data. As a result, data such as X-ray detection data is transmitted from the rotating unit 10 to the fixed unit 11 using light as a medium.

Here, each of the light emitting elements 121, 122, ... 1
2n has a predetermined irradiation angle, but the light emitting elements 121, 122, so that the irradiation areas of the light emitting elements 121, 122, ... 12n overlap on the wall surface of the hole of the fixed portion 11.
The arrangement interval of 12n is set. Therefore, the light receiving element 15 always receives the light from any one or two light emitting elements during the rotation of the rotating unit 10, and all the light emitting elements 121, 122, ... 12n have the same transmission data. Therefore, the transmission data is not interrupted in the light receiving element 15 even if the rotating unit 10 is rotating, because the data is driven simultaneously.

On the other hand, a large number of light receiving elements (for example, photodiodes) 171, 172, ... 17n are arranged at regular intervals on the outer peripheral surface of the housing of the rotating portion 10. The light receiving elements 171, 172, ... 17n are arranged on the same plane as the arrangement surface of the light emitting elements 121, 122, ... 12n, and are arranged at positions slightly deviated in the rotation axis direction of the rotating unit 10. Has been done. These light receiving elements 171 and 1
A receiving unit 18 is commonly connected to 72, ..., 17n, and is detected by the receiving unit 18 as received data.

Further, one light emitting element (eg, light emitting diode) 19 is provided on the wall surface of the hole of the fixed portion 11 facing the outer peripheral surface of the rotating portion 10. This light emitting element 19
Is driven by the driver 20 provided in the fixed unit 11 according to the transmission data 21, and transmits the data via light.

By the way, the light receiving element 15 and the light emitting element 19 provided on the fixed portion 11 are provided in a member which is not shown but has a circular arc shape and is removable. Therefore, maintenance is difficult at the portion where the arc-shaped member and the rotating portion 10 face each other, but at other portions, the light-emitting elements 121 and 12 of the rotating portion 10 are not removed without removing the arc-shaped member.
2, ... 12n and light receiving elements 171, 172, ... 17n
Is ready for maintenance.

As described above, in the first embodiment, the plurality of light emitting elements 121, 122, ...
2n is provided and a plurality of light receiving elements 171, 172,
17n are provided, and on the other hand, one light receiving element 15 and one light emitting element 19 are provided on the fixed portion 11, so that each one light receiving element 15 and one light emitting element 19 provided on the fixed portion 11 are provided even while the rotating portion 10 is rotating. By transmitting and receiving light to and from the rotating unit 10, data can be transmitted by light between the rotating unit 10 and the fixed unit 11 with a simple configuration.

Moreover, since the fixing portion 11 is provided with one light receiving element 15 and one light emitting element 19, each light emitting element and each light receiving element can be provided by providing these light receiving element 15 and light emitting element 19 in an arc-shaped member. Maintenance work can be done easily.

Further, each of the light emitting elements 121 to 12n irradiates the light receiving element 15 directly with light, and the light received by the light receiving element 15 is not interrupted even during rotation. Since 121 to 12n are provided,
The light emitting elements 121 to 12n and the light receiving element 15 can be brought close to each other. Since the distance between the light emitting element and the light receiving element is short, optical means such as light converging is not always necessary, and as a result, the configuration of the optical system is simple and the light utilization efficiency is high, so that it is inexpensive. The device can be realized using a light emitting diode.

Furthermore, since non-contact data transmission is carried out using light as a medium, periodical maintenance, which is necessary in the conventional slip ring system, such as replacement of parts is unnecessary, and contact failure and contact resistance are eliminated. There is no problem and the data transmission quality and reliability are improved. Also, since it is optical transmission, the speed of data transmission is increased,
Transmission time is reduced. Further, the transmission accuracy is high because it is not affected by electromagnetic noise.

It should be noted that, here, the rotating portion 10 to the fixed portion 1
Although the transmission of the X-ray detection data to 1 has been shown, a large number of light emitting elements and light receiving elements are provided in the fixed part 11, and the rotating part 10 is provided with one each.
Even if one light receiving element and one light emitting element are provided, the X-ray exposure control signal can be transmitted by light as in the above. Next, an embodiment in which a plurality of transmission channels are provided so that a plurality of data can be transmitted simultaneously and the transmission efficiency is improved will be described.

FIG. 2 shows an X to which the second embodiment of the present invention is applied.
It is a block diagram which shows the circuit structure of a line CT scanner. As shown in FIGS. 3 and 4, X-rays are radiated from an X-ray tube 31 arranged in a rotating part 30 surrounded by a donut-shaped housing, and a subject 32 arranged in the central space of the rotating part 30.
The X-rays that have passed through face the X-ray tube 31 and face the X-ray tube 31 as well.
It is detected by the detector 33 arranged at 0. Although FIG. 3 shows a third generation CT scanner, the present invention is not limited to this and can be applied to any generation CT scanner.

In FIG. 2, the output from each channel of the detector 33 is collected by a data acquisition system (DAS) 34 and supplied to a parallel / serial (P / S) converter 35 as a parallel digital signal. This P
The serial data output from the / S converter 35 is supplied to the switching unit / driver 36.

A unit controller 37 for controlling each part of the rotary unit is provided in the rotary unit 30, and the output of the unit controller 37 is supplied to the X-ray tube 31, the DAS 34, and the switching unit / driver 36. .

The switching unit / driver 36 includes a plurality of light emitting elements (electrical / optical conversion elements; E / O) 381, 382 ,.
It has a function of dividing n into a predetermined number of light emitting element groups T1 to T12 and driving each group T1 to T12 according to either the first or second transmission data. Thereby, the rotating unit 30
Therefore, two transmission channels from the fixed unit 40 to the fixed unit 40 are provided. Here, the X-ray detection signal is transmitted on one channel, and various control signals are transmitted on other channels.

In the first embodiment described above, the transmission direction of the light for transmitting the data is the radial direction of the gantry, but in the second embodiment, the light is transmitted in the axial direction of the rotating portion 30 as shown in FIG. . Therefore, a large number of light emitting elements 381, 382, ... 38n are provided on the end surface of the rotating portion 30 at a predetermined interval, and two light receiving elements for receiving the first and second transmission data are provided on the end surface of the fixed portion 40 opposed thereto. Element group (optical / electrical conversion element; O /
E) 411 and 412 are provided.

FIG. 5 schematically shows the arrangement of the light emitting element and the light receiving element, and the state of transmission from the rotating portion 30 to the fixed portion 40 is shown in the center thereof. As shown in the figure, the respective light receiving element groups 411 and 412 are arranged so as to be offset from each other by 180 ° in a part of the fixed portion.

In order to transmit data from the fixed portion 40 to the rotating portion 30, each light emitting element group 4 is also provided on the end surface of the fixed portion 40.
21 and 422 are provided 180 degrees apart from each other, and a plurality of light receiving element groups 391, 392, ... 39n for receiving the first and second transmission data are arranged on the end surface of the rotating portion 30 which faces them. Then, these light receiving element groups 391, 392,
The output of 39n is supplied to the unit controller 37.

FIG. 6 shows details of the light emitting element and the light receiving element.
Light emitting elements 381, 382, ... 38n or 421, 422
Is used so that the light emitting surface spreads in the circumferential direction, as shown in FIG. However, since the element having weak directivity relatively increases the amount of attenuation of the light emission power, the distance between the light emitting element and the light receiving element needs to be several cm or less.

Further, in order to prevent diffusion in directions other than the circumferential direction and block light from the light emitting elements 421, 422 or 381, 382, ... 38n for transmission in the reverse direction,
A hood 50 is provided in each of the light receiving element groups 421 and 422. The surface of the hood 50 may be anything as long as it has a high reflectance. The hood 50 also acts as a means for blocking outside light. Each light receiving element group 411, 412
Is, as shown in FIG. 7, two light receiving elements 41a and 41b.
Consists of.

As described above, a plurality of light emitting elements and light receiving elements are grouped together to emit light and receive light.
Data transmission is not affected even if any of the light receiving elements is damaged. For example, in the case of FIG.
Data transmission is performed until one light receiving element 41a or 41b and two non-adjacent light emitting elements 38i-1 and 38i + 1 are damaged. Therefore, the reliability of the entire system is improved.

The light emitting elements 381, 382, ... 38n or 421, 422 are arranged at intervals, the rotating portion 30 and the fixed portion 40.
The interval between the light emitting elements 381, 391, 392, ... 39n on the light receiving elements 41a, 41b or 391, 392, ... 39n is the same as in the first embodiment so that the transmission data is not interrupted during the rotation of the rotating unit 30. 382, ... 38n or 391, 392,
The irradiation areas of 39n are set to overlap.

The first transmission data output from the light receiving element group 411 is converted into parallel digital data by the S / P converter 43, and is input to the image reconstruction unit 44 as X-ray detection data (projection data). It The image reconstructed by the image reconstructing unit 44 is displayed on the monitor 45.

A unit controller 46 for controlling each part of the fixed part is also provided in the fixed part 40, and the light receiving element group 4 is provided.
The second transmission data output from 12 is supplied to the unit controller 46.

The unit control section 46 supplies two data to be transmitted from the fixed section 40 to the rotating section 30 to the switching section / driver 47. The switching unit / driver 47 drives each of the light emitting elements 421 and 422 according to either the first or second transmission data. As a result, two transmission channels from the fixed portion 40 to the rotating portion 30 are provided.
Various control signals are transmitted from the fixed unit 40 to the rotating unit 30 using two channels. Next, the operation of simultaneously transmitting two data according to this embodiment will be described. here,
A case of transmitting data from the rotating unit 30 to the fixed unit 40 will be described. As shown in FIG. 8, each of the light emitting elements 381, 382, ...
It is divided into two light emitting element groups T1 to T12.

The switching unit / driver 36 is provided for each of the groups T1 to T12.
(I = 1 to 12) are driven separately, and the fixed portion 40
Separate signals are transmitted to the respective light receiving element groups 411 and 412 on the side. However, since the light emitting element groups capable of irradiating light to the respective light receiving element groups 411 and 412 change with the rotation of the rotating section 30, the data given to the respective light emitting element groups Ti are supplied to the rotating section 3.
It is necessary to switch in conjunction with the rotation of 0. In order to detect the rotation angle of the rotating part 30, an optical sensor 51 is attached to the rotating part 30, and slits S1 to S12 for driving the optical sensor 51 are arranged on the fixed part 40 side. . That is, the optical sensor 51 outputs a detection pulse every time it passes through the slit position. Although not shown, the detection pulse is supplied to the switching unit / driver 36.

FIG. 9 shows how the transmission data applied to each light emitting element is switched. In each of the light emitting element groups T1 to T12, the transmission data is switched every half rotation of the rotating unit 30 (that is, every time six detection pulses are output from the optical sensor 51). For example, the light-emitting element group T1 is supplied with transmission data (second transmission data) to the light-receiving element group 412 in response to the second detection pulse output, and when the light-receiving element group 412 passes in front of the second transmission pulse, the second transmission data is transmitted. It emits light according to the data. After that, in accordance with the eighth detection pulse output, the light receiving element group 41
When the data is switched to the transmission data for 1 (first transmission data) and passes in front of the light receiving element group 411, light emission is performed according to the first transmission data.

In this way, each light emitting element group T1, T2, ...
T12 switches the transmission data in response to the rotation detection pulse from the optical sensor 51, so that predetermined signals are always transmitted to the light receiving element groups 321 and 322 as a whole. In the upper part of FIG. 9, the horizontal axis represents time, and the vertical axis represents movement on the rotating portion side as viewed from the fixed portion side. Each light emitting element group shown in the lower part of FIG. 9 emits data to the light receiving element group 411 at the position shown by the solid line, and emits data to the light receiving element group 412 at the position shown by the broken line.

As described above, according to the second embodiment, data can be bidirectionally transmitted between the rotating portion 10 and the fixed portion 11 with a simple structure. Further, since the light receiving element groups 411 and 412 and the light emitting element groups 421 and 422 are provided in a part of the fixed part, each light emission blocking in the rotating part 30 except the rotating part 30 facing the light receiving elements and the light emitting elements. Also, maintenance of the light receiving element can be performed. In this case, of course, the maintenance can be easily performed without removing the rotating portion 30.

Further, by increasing the number of data that can be transmitted at the same time, there is an effect that the data transmission speed becomes faster and the mounting space does not increase even if the number of transmission channels is increased. Further, in the above description, all the light emitting element groups within the rotational position range of the slits S5 to S11 emit light according to the first transmission data, and all the light emitting element groups within the rotational position range of the slits S11 to S5 are included. Although the light is emitted according to the second transmission data, in reality, only the light emitting element group within the rotational position range of the slits S3 to S1 or S9 to S7 contributes to the transmission. Therefore, power consumption can be reduced by not driving the light emitting element groups that are not included in the rotational position range and are not involved in transmission.

The rotation angle of the rotating portion may be detected by using a dedicated rotary encoder, or by using the rotation position data from another unit that recognizes the rotation position. . For convenience of explanation, the case of transmitting two pieces of data is shown, but if more data needs to be transmitted, the light emitting portions may be further divided or the timing of switching may be finer. In this way, it is possible to send data up to half the number of light emitting elements. In order to transmit a plurality of data at the same time, it is necessary to provide the same number of light receiving element groups as the number of transmitted data.

Next, FIG. 10 shows a modification of the second embodiment.
There is a configuration shown in. In the second embodiment, the light transmission direction is the direction along the rotation axis of the rotating part. However, as shown in the figure, the light receiving element and the light emitting element are attached to the circumferential surface, and each fixed piece having an arc shape in the radial direction. The light emitting and light receiving elements may be opposed to 52 and 52. As a result, the maintenance work can be facilitated as in the first embodiment. The hood is omitted in FIG.

By the way, in the above-mentioned embodiment, the level of the transmission signal may vary when the rotating section 30 rotates. This is because the relative positional relationship between the light emitting element and the light receiving element changes, so that the level of the optical signal received by the light receiving element changes. That is, the transmission signal undergoes amplitude modulation according to the rotation of the rotating unit. Generally, in order to deal with such amplitude modulation, it is necessary for the receiving circuit to have a wide dynamic range. But,
The dynamic range has a trade-off relationship with the S / N, and it has heretofore been difficult to realize a wide dynamic range while securing the S / N. Therefore, a third embodiment will be described below, which can deal with the fluctuation of the signal level due to the rotation of the rotating portion without the need to widen the dynamic range.

FIG. 11 is a schematic view of the third embodiment.
The third embodiment is almost the same as that of the first embodiment shown in FIG. 3 and is different only in that a plurality of (here, two) light receiving elements 151 and 152 are provided. However, unlike the second embodiment, these light receiving elements 151, 152 are provided adjacent to each other, and the light emitting element 121
, 122, ... 12n are emitted by the same transmission data. That is, although a plurality of light receiving elements are provided, there is only one transmission channel.

The distance between these light receiving elements 151 and 152 (D
/ 2) is set to half of the interval D of the light emitting elements 121, 122, ... 12n arranged at equal intervals on the outer periphery of the rotating portion 10 as shown in FIG. As a result, when one light receiving element 151 faces one of the light emitting elements 121, the other light receiving element 152 is located at an intermediate position between the adjacent light emitting elements 122.

The outputs of these light receiving elements 151 and 152 are
The receiving unit 16 combines the signals as shown in FIG. 13 to form one received signal. Optical signals from the light emitting elements 121, 122, ... 12n driven according to the transmission data are received by the light receiving elements 151, 152, respectively, and current signals is1, is1, respectively.
converted to is2. The current signals is1 and is2 are input to the current / voltage conversion amplifier A1 having an addition function. If the feedback resistance is Rf, the output Vs of the amplifier A1 is Rs.
It becomes f (is1 + is2). This output Vs is compared with the reference voltage Vref in the comparator A2 at the next stage and converted into a digital signal. Alternatively, current / voltage conversion may be performed for each light receiving element, and then the received signals obtained there may be added and converted into a digital signal.

As described above, the output current signals is1 and is2 of the light receiving elements 151 and 152 are shown in FIG.
As shown in FIG. 4, it fluctuates in a sine wave shape. This period is equal to the distance D / 2 between the light receiving elements 151 and 152. Here, since both light receiving elements 151 and 152 have a phase difference of 180 ° as shown in FIG. 12, when one output signal becomes maximum, the other output signal becomes minimum. Therefore, the output Vs of the amplifier A1 for adding both signals is an average value of both and becomes constant.

By thus averaging the outputs of the two light receiving elements, the light receiving unit outputs can be averaged, the amplitude modulation of the light receiving unit outputs can be suppressed, and the current / voltage conversion can always be performed with the optimum gain. can do. Therefore, it is not necessary to widen the dynamic range, as a result, S / N is improved, bit errors due to noise at low level signals can be prevented, and bit error rate, which is reliability of data transmission, is improved. You can

As described above, according to the third embodiment,
In addition to the effects of the second embodiment, the output of the light receiving unit can always be kept constant regardless of the change in the relative positional relationship between the light emitting element and the light receiving element due to the rotation of the rotating unit, and correct data can be obtained. Can be transmitted. When the third embodiment is applied to the second embodiment, the light receiving parts 411, 412 and 39 of the second embodiment are used.
Each of 1 to 39n may be composed of a plurality of light receiving elements. The present invention is not limited to the above-described embodiments, and may be modified without departing from the scope of the invention. For example, in the above description, the example applied to the X-ray CT scanner has been described, but the present invention is not limited to this.

Further, as shown in FIG. 15, an arc-shaped fixing plate 60 is provided on the side of the fixing portion, and a plurality of light emitting elements 61 and light receiving elements 62 are arranged on the fixing plate 60.
You may comprise so that the predetermined | prescribed angle area | region of 0 may be covered.

By forming the fixing plate 60 in this manner, the light emitting elements 71 and the light receiving elements 7 arranged on the rotating portion 70.
The number of 2 can be reduced. Also in this case, two types of data can be transmitted by providing the fixing portion 60 at two places.

Even with such a construction, the maintenance work can be facilitated by forming either the rotating portion or the fixed portion in an arc shape as in the above-described embodiments.

[0066]

As described above, according to the present invention, it is possible to provide a data transmission device which can transmit a large amount of data with a simple structure and can be easily maintained.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of a data transmission device according to the present invention.

FIG. 2 is a block diagram showing a configuration of a second embodiment of a data transmission device according to the present invention.

FIG. 3 is a front view of a gantry according to a second embodiment.

FIG. 4 is a diagram showing a light transmission direction according to a second embodiment.

FIG. 5 is a diagram showing an arrangement of light emitting elements and light receiving elements in a rotating portion and a fixed portion in the second embodiment.

FIG. 6 is a view showing a hood attached to a light receiving element in the second embodiment.

FIG. 7 is a diagram showing a relationship between an arrangement interval of the light emitting elements and an interval between the light receiving elements in the second embodiment.

FIG. 8 is a diagram for explaining an operation when two data are simultaneously transmitted in the second embodiment.

FIG. 9 is a diagram showing a switching timing of a light emitting element and a light receiving element in the operation of the second embodiment.

FIG. 10 is a diagram showing a modification in which the optical transmission direction is changed in the second embodiment.

FIG. 11 is a configuration diagram showing an outline of a third embodiment of a data transmission device according to the present invention.

FIG. 12 is a diagram showing an arrangement relationship between a light emitting element and a light receiving element of the third embodiment.

FIG. 13 is a circuit diagram of a light receiving circuit according to a third embodiment.

FIG. 14 is a signal waveform diagram of the light receiving circuit of the third embodiment.

FIG. 15 is a diagram showing a modified example of the present invention.

FIG. 16 is a block diagram of a conventional device.

[Explanation of symbols]

10 ... Rotating part, 11 ... Fixed part, 121 to 12n ... Light emitting element, 13 ... Driver, 15 ... Light receiving element, 151, 152
... light receiving element, 16 ... receiving section, 171 to 17n ... light receiving element, 18 ... receiving section, 19 ... light emitting element, 20 ... fixing section, 3
0 ... Rotating unit, 31 ... X-ray tube, 32 ... Subject, 33 ... Detector, 34 ... Data acquisition system, 35 ... Parallel / serial converter, 36 ... Switching unit / driver, 37 ... Unit control unit, 381 ... 38n ... Light emitting element, 40 ... Fixed part, 4
11, 41 2 ... Light receiving element group, 421, 422 ... Light emitting element group, 391-39n ... Light receiving element group, 50 ... Hood.

Claims (4)

[Claims] 1. A data transmission device for bidirectionally transmitting data between a first member and a second member, the positions of which relatively change, wherein a plurality of members are provided over the entire first or second member. At least one second optical transceiver element which is provided in a part of the second or first member and which transmits and receives the data to and from each of the first optical transceiver elements through light. A data transmission device comprising: 2. The first and second relative positions that periodically change.
In a data transmission device for bidirectionally transmitting data to and from a member, a plurality of optical transmission and reception element groups provided in the first or second member and driven according to a plurality of the data; At least one optical transmission / reception element that is provided in the first member and transmits / receives the data to / from the optical transmission / reception element group through light, and a predetermined value regardless of a change in relative positions of the first and second members. Of the plurality of transmission data supplied to each of the optical transmission / reception elements so that the transmission data of each of the transmission / reception elements of the first and second members are changed in each cycle. A data transmission device comprising: a switching unit. 3. A ring-shaped first member, an arc-shaped second member that moves on the circumference of the first member, and a plurality of members provided on the circumference of the first member. A first optical transmitter / receiver device, and at least one second optical transmitter / receiver device provided on the second member and transmitting / receiving the data to / from each of the first optical transmitter / receiver devices via light. A data transmission device characterized by. 4. A ring-shaped first member, an arc-shaped second member that periodically moves on the circumference of the first member, and a first member that is provided on the circumference of the first member. A plurality of first optical transmission / reception element groups, and at least one second optical transmission / reception element, which is provided on the second member and transmits / receives the data to / from the first optical transmission / reception element group, A plurality of transmission data supplied to each optical transmission / reception element so that predetermined transmission data is transmitted / received to / from each predetermined optical transmission / reception element irrespective of changes in relative positions of the first and second members. And a means for switching at each cycle of the change of the relative positions of the first and second members, and a data transmission device.