JP2005253797A - Receiver, transmitter and transmitting/receiving system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely select and switch an optimum antenna with great intensity of receiving electric field by a simple structure. <P>SOLUTION: A selection control part C1 switches receiving antennas A1-An one by one in a horizontal blanking period when dummy pulses for measuring the intensity of receiving electric field is added, and makes the respective antennas detect the intensity of receiving electric field. Then, the selection control part switches the antenna to the receiving antenna A1-An which detected the greatest intensity of receiving electric field, and makes the antenna receive a picture signal in a picture line period. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a transmission device that transmits an imaged video signal, a reception device that receives the video signal using a plurality of antennas, and a transmission / reception system that includes the transmission device and the reception device. The present invention relates to a transmission / reception system that receives a radio video signal transmitted from a capsule endoscope using a plurality of antennas outside a subject.

  In recent years, swallowable capsule endoscopes have appeared in the field of endoscopes. This capsule endoscope is provided with an imaging function and a wireless communication function. Capsule endoscopes are peristaltic in the body cavity, for example, the stomach, small intestine, etc., after being swallowed from the patient's mouth for observation (examination) and before being spontaneously discharged from the human body. It has the function to move according to and to image sequentially.

  While moving inside the body cavity, image data imaged inside the body by the capsule endoscope is sequentially transmitted to the outside by wireless communication and stored in a memory provided in an external receiver. When the patient carries the receiver having the wireless communication function and the memory function, the patient can freely act even during the period from swallowing the capsule endoscope until it is discharged. Thereafter, the doctor or nurse can make a diagnosis by displaying an organ image on the display based on the image data stored in the memory.

  Generally, a receiver distributes a plurality of antennas for receiving a video signal transmitted from a capsule endoscope outside the body, and selects and receives one antenna with few reception errors of the video signal. ing. In Patent Document 1, reception switching of a plurality of antennas arranged outside the body is performed, and the position of the capsule endoscope in the body, which is a transmission source of the video signal, based on the electric field intensity received by each antenna. A receiver for detecting is described.

Japanese Patent Laid-Open No. 2003-19111

  However, in the conventional receiver, when one antenna is selectively switched from a plurality of antennas and one receiving unit (tuner) is used, the received electric fields of the plurality of antennas are received within a reception field strength measurement period such as a preamble. There was a problem that the strength had to be measured.

  Here, when the number of antennas increases, in order to measure the received field strength of all antennas within the received field strength measurement period described above, a changeover switch capable of high-speed switching of antennas and high-speed received field strength measurement processing are realized. There was a problem that a circuit configuration to be required.

  The present invention has been made in view of the above, and provides a receiving device, a transmitting device, and a transmission / reception system capable of reliably selecting and switching an optimum antenna having a large received electric field strength with a simple configuration. Objective.

  In order to solve the above-described problems and achieve the object, a receiving apparatus according to claim 1 is a wireless signal transmitted from a moving transmitting apparatus and includes at least an information main body including an information main body and information for synchronization. In a receiving apparatus that receives a frame-structured radio signal including an additional unit using a plurality of antennas, a dummy signal for measuring reception intensity is provided in an empty portion in the information main body in which an arrangement position is determined in advance. Each antenna is sequentially switched in the vacant portion of the added wireless signal to detect the received electric field strength of each antenna, and the antenna other than the vacant portion is switched to the antenna that has detected the largest received electric field strength. Control means for performing control to receive a radio signal of the main body is provided.

  The receiving device according to claim 2 is characterized in that, in the above-mentioned invention, the control means sequentially detects each received antenna intensity of each antenna including a part of the additional unit. To do.

  According to a third aspect of the present invention, in the above invention, the control means measures the received electric field strengths of a plurality of antennas in at least a part of the empty part of the information main body part and a part of the additional part. It is characterized by doing.

  According to a fourth aspect of the present invention, in the above invention, the information body is a video signal, and the empty portion is a horizontal blanking period.

  According to a fifth aspect of the present invention, there is provided a transmission apparatus that transmits a video signal obtained by imaging as a radio signal, and causes a reception apparatus including a plurality of antennas to receive the video signal. During the blanking period, each antenna of the receiving apparatus is sequentially switched and received, and a dummy signal for measuring the received electric field strength for detecting the received electric field strength at each antenna is added and transmitted.

  A transmission / reception system according to claim 6 is a transmission / reception system including a transmission device that transmits a video signal obtained by imaging as a radio signal, and a reception device that receives the video signal using a plurality of antennas. The transmission device includes dummy signal addition means for adding and transmitting a dummy signal during a horizontal blanking period in the video signal, and the reception device sequentially switches the antennas during the horizontal blanking period to transmit the dummy signal. Control means for detecting the received electric field strength at each of the antennas, switching to the antenna that has detected the largest received electric field strength, and controlling the antenna to receive a video signal other than the horizontal blanking period. Features.

  In the transmission / reception system according to claim 7, in the above invention, the control means sequentially switches each antenna including a reception signal strength measurement synchronization signal period added to the video signal to increase the reception field strength. It is made to detect.

  In the receiving apparatus according to the present invention, the control means sets each antenna in the empty portion of the radio signal in which a dummy signal for measuring reception intensity is added to the empty portion in the information main body portion where the arrangement position is determined in advance. Switch sequentially to detect the received field strength of each antenna, and switch to the antenna that detected the largest received field strength to control the antenna to receive the radio signal of the information body portion other than the empty portion. As a result, it is not necessary to add a new period for measuring the received electric field strength to the adding unit, so that the transmission time of the radio signal can be shortened, the power consumption on the transmitter side can be reduced, and the dummy signal can be When it is provided in the blanking period, the antenna switching can be reliably synchronized, so that the antenna switching accuracy is improved.

  Hereinafter, a wireless in-vivo information acquiring system including a receiving device, a transmitting device, and a transmission / reception system, which is the best mode for carrying out the present invention, will be described.

(Embodiment)
This wireless intra-subject information acquisition system corresponds to a transmission / reception system, and uses a capsule endoscope as an example of a transmission device (intra-subject introduction device).

  FIG. 1 is a schematic diagram showing an overall configuration of a wireless in-vivo information acquiring system. As shown in FIG. 1, the wireless in-vivo information acquisition system includes a receiving device 2 having a wireless receiving function, and a body cavity image that is introduced into the body of the subject 1 to capture an image of the body cavity. A capsule endoscope (intra-subject introduction device) 3 that wirelessly transmits data such as signals. In addition, the wireless in-vivo information acquiring system performs data exchange between the display device 4 that displays the intra-body cavity image based on the video signal received by the receiving device 2 and the receiving device 2 and the display device 4. The portable recording medium 5 is provided. The receiving device 2 includes a receiving jacket 2a worn by the subject 1 and an external device 2b that performs processing of a radio signal received through the receiving jacket 2a.

  The display device 4 is for displaying an in-vivo image captured by the capsule endoscope 3, and has a configuration such as a workstation that displays an image based on data obtained by the portable recording medium 5. Have Specifically, the display device 4 may be configured to directly display an image by a CRT display, a liquid crystal display, or the like, or may be configured to output an image to another medium such as a printer.

  The portable recording medium 5 can be attached to and detached from the external device 2b and the display device 4, and has a structure capable of outputting or recording information when being inserted into both. Specifically, the portable recording medium 5 is inserted into the external device 2 b and transmitted from the capsule endoscope 3 while the capsule endoscope 3 is moving in the body cavity of the subject 1. Record the data. Then, after the capsule endoscope 3 is ejected from the subject 1, that is, after imaging of the inside of the subject 1 is finished, the capsule endoscope 3 is taken out from the external device 2b and inserted into the display device 4 to be attached to the display device. The data recorded by 4 is read out. When data is transferred between the external device 2b and the display device 4 by a portable recording medium 5 such as a compact flash (registered trademark) memory, and the external device 2b and the display device 4 are connected by wire. In addition, the subject 1 can freely operate during imaging in the body cavity, and also contributes to shortening of data transfer time with the display device 4. Here, the portable recording medium 5 is used for data transfer between the external device 2b and the display device 4. However, the present invention is not limited to this, and the external device 2b has another built-in recording device. In order to exchange data with the display device 4, both may be connected by wire or wirelessly.

  Here, the capsule endoscope 3 will be described. FIG. 2 is a block diagram schematically showing the configuration of the capsule endoscope 3. As shown in FIG. 2, the capsule endoscope 3 includes an LED 19 for irradiating an imaging region when photographing the inside of the subject 1, an LED driving circuit 20 for controlling the driving state of the LED 19, and the LED 19. It comprises a CCD 21 as an imaging means for imaging the irradiated area, and a signal processing circuit 22 that processes the image signal output from the CCD 21 into imaging information of a desired format. The capsule endoscope 3 includes a CCD driving circuit 25 that controls the driving state of the CCD 21 and an RF transmission unit that generates an RF signal by modulating image data captured by the CCD 21 and processed by the signal processing circuit 22. 23, a transmission antenna unit 24 that transmits an RF signal output from the RF transmission unit 23, and a system control circuit 26 that controls the operation of the LED drive circuit 20, the CCD drive circuit 25, and the RF transmission unit 23. The CCD 21, the signal processing circuit 22, and the CCD driving circuit 25 are collectively referred to as an imaging circuit 27.

  By providing these mechanisms, the capsule endoscope 3 acquires image information of the region to be examined illuminated by the LED 19 by the CCD 21 while being introduced into the subject 1. The acquired image information is signal-processed into a video signal by the signal processing circuit 22, and this video signal is converted into an RF signal in the RF transmission unit 23 and then transmitted to the outside via the transmission antenna unit 24.

  Here, the signal processing circuit 22 includes a dummy signal adding unit 22a. The dummy signal adding unit 22a synchronizes with the horizontal synchronizing signal and the vertical synchronizing signal of the video signal, and receives each of the receptions described later within the horizontal blanking period. A dummy pulse for measuring the received intensity used when the received electric field intensity at each antenna is detected from the radio signal received by the antenna is added. For example, a counter synchronized with the horizontal synchronization signal and the vertical synchronization signal is provided, and a dummy pulse is generated using the count value of this counter as a reference and embedded in the horizontal blanking period. The position and frequency of this dummy pulse are arbitrary as long as they are within the horizontal blanking period. Further, it is not necessary to add a dummy pulse in all horizontal blanking periods, and a dummy pulse may be added only in a horizontal blanking period at a necessary location.

  In addition, the capsule endoscope 3 includes a sensor unit 35 that detects a signal such as predetermined magnetism, light, and radio waves, and an LED driving circuit, a CCD driving circuit 25, based on the value detected by the sensor unit 35, An RF transmission unit 23 and a drive control unit 34 that controls driving of a system control circuit 26 that controls the overall processing of each unit are provided. The sensor unit 35 is realized by, for example, a pH sensor, and detects whether or not the capsule endoscope 3 has reached a predetermined position in the subject. Based on this result, the drive control unit 34 performs the control of each unit. Control the drive. Thereby, power consumption can be suppressed.

  Further, the drive control unit 34 receives power supplied from the battery 40 as an energy supply source via the power switch 33 in the power switch circuit 30. The battery 40 is realized by a button type battery such as silver oxide. The power switch 33 is a main power switch of the capsule endoscope 3 so to speak. The power switch circuit 30 further includes a signal detection circuit 31 and a switch control circuit 32. A signal detection circuit 31 as an external signal detection means for detecting a signal from the outside of the capsule endoscope 3 is realized by a reed switch, and is turned on and off by the proximity and separation of the magnet 50 with respect to the reed switch. In other words, the switch control circuit 32 that performs an on / off operation depending on whether or not a magnetic force acts on the reed switch is configured to toggle the on / off of the power switch 33 based on the control signal from the signal detection circuit 31, that is, the on / off signal. Control. The power switch 33 is turned on and off by the magnet 50 before being introduced into the subject, and an operation check of the capsule endoscope 3 is performed.

  Here, the receiving apparatus 2 will be described with reference to FIG. The receiving device 2 has a function of receiving in-vivo image data wirelessly transmitted from the capsule endoscope 3. FIG. 3 is a block diagram schematically showing the configuration of the receiving device 2. As shown in FIG. 3, the receiving device 2 has a shape that can be worn by the subject 1, a receiving jacket 2a having receiving antennas A1 to An, and an external device that processes received radio signals and the like. 2b. Each of the receiving antennas A1 to An may not be provided in the receiving jacket 2a so as to be directly attached to the outer surface of the subject, and may be detachable from the receiving jacket 2a.

  The external device 2b has a function of processing a radio signal transmitted from the capsule endoscope 3. Specifically, as shown in FIG. 3, the external device 2b is connected to the selector switch SW for switching the connection of the receiving antennas A1 to An and the subsequent stage of the selector switch SW, and is connected by the selector switch SW. The receiving circuit 11 amplifies and demodulates the radio signals from the receiving antennas A1 to An, and a signal processing circuit 12 and a sample hold circuit 15 are connected to the subsequent stage of the receiving circuit 11. An A / D converter 16 is further connected to the subsequent stage of the sample hold circuit 15. The control unit C includes a selection control unit C1 as control means, and includes a signal processing circuit 12, an A / D conversion unit 16, a storage unit 13 corresponding to the portable storage medium 5, a display unit 14, and a switching control unit SC. Connecting. The switching control unit SC has strength receiving antenna number information N1 and video receiving antenna number information N2. Based on these number information, the switching control unit SC issues a switching instruction of the changeover switch SW, and the sample hold circuit 15, A / D Instruct the processing timing of the conversion unit 16 and the selection control unit C1. The power supply unit 17 supplies power to each unit described above, and is realized by, for example, a battery.

  The change-over switch SW of the external device 2b selectively switches any one of the receiving antennas A1 to An based on the switching instruction from the switching control unit SC, and the radio signal from the switched receiving antennas A1 to An. Is output to the receiving circuit 11.

  As described above, the receiving circuit 11 amplifies the radio signal, outputs the demodulated video signal S1 to the signal processing circuit 12, and also receives the received intensity signal S2 that is the received electric field intensity of the amplified radio signal as the sample hold circuit 15. Output to. The video data processed by the signal processing circuit 12 is stored in the storage unit 13 by the control unit C and displayed and output by the display unit 14. The signal sampled and held by the sample and hold circuit 15 is converted into a digital signal by the A / D conversion unit 16 and taken into the control unit C. The selection control unit C1 of the control unit C performs a part of a synchronization period described later and The receiving antenna that has received the largest received electric field strength among the received electric field strengths received during the horizontal blanking period within the video signal period is selected as the receiving antenna for the video signal period, and other than the selected receiving antenna. Are sequentially selected as reception antennas in a part of the synchronization period and in the horizontal blanking period in the video signal period, and the respective reception antenna numbers are designated as video reception antenna number information N2 and intensity reception antenna number information. The signal S4 for N1 is output to the switching control unit SC. In addition, the control unit C selects the reception electric field strength in the horizontal blanking period in a part of the synchronization period and the video signal period, and the reception electric field strength in the video reception period excluding at least the horizontal blanking period at that time. The image is stored in the storage unit 13 together with the video data in association with the receiving antenna. The stored received electric field strength of each receiving antenna becomes information for calculating the position of the capsule endoscope 3 in the body when the video data is received.

  The switching control unit SC holds the strength receiving antenna number information N1 and the video receiving antenna number information N2 instructed by the selection control unit C1, and the strength is used in a part of the synchronization period and the horizontal blanking period in the video signal period. The changeover switch SW is instructed to selectively connect the receiving antennas A1 to An corresponding to the receiving antenna number information N1, and at least the reception corresponding to the video receiving antenna number information N2 is received during the video receiving period excluding the horizontal blanking period. A signal S5 for instructing the changeover switch SW to selectively connect the antennas A1 to An is output to the changeover switch SW, and a signal S3a for instructing a sample hold timing by the sample hold circuit 15 and A by the A / D conversion unit 16 / D conversion timing signal S3b, selection control timing by selection control unit C1 And outputs a signal S3c instructing grayed.

  Here, with reference to FIG. 4 and FIG. 5, a detailed configuration of the sample hold circuit 15 and the changeover switch SW will be described. First, in FIG. 4, a sample and hold circuit 15 includes a pulse generator 15a that generates a sample and hold pulse, an intensity reception sample and hold that samples and holds the received electric field strength during a horizontal blanking period within a part of the synchronization period and the video reception period. A circuit 15b, and a video reception sample / hold circuit 15c that samples and holds the received electric field intensity during the video reception period excluding the horizontal blanking period.

  The pulse generator 15a generates a pulse SH_KYODO and a pulse SH_EIZO that indicate the timing and period of sample hold by the intensity reception sample hold circuit 15b based on the signal S3a input from the switching control unit SC. The pulse SH_KYODO and the pulse SH_EIZO are output to the switch SW1 of the intensity reception sample / hold circuit 15b and the switch SW2 of the video reception sample / hold circuit 15c, respectively.

  The intensity reception sample / hold circuit 15b buffers the reception intensity signal S2 input from the reception circuit 11 by the amplifier Amp1. On the other hand, the switch SW1 is turned on for the period indicated from the timing indicated by the pulse SH_KYODO, and the signal buffered by the amplifier Amp1 is accumulated by the charge being accumulated in the capacitor C1 and being turned off. The electric charge is buffered by the amplifier Amp2, and is output to the A / D converter 16 as a signal KYODO_LVL indicating the received electric field strength during a part of the synchronization period and the horizontal blanking period within the video reception period.

  On the other hand, the video reception sample / hold circuit 15c receives the signal amplified by the amplifier Amp1 from the intensity reception sample / hold circuit 15b. The switch SW2 is turned on for a period indicated from the timing indicated by the pulse SH_EIZO, and the signal buffered by the amplifier Amp1 is stored in the capacitor C2, and the accumulated voltage The value is buffered by the amplifier Amp3 and output to the A / D converter 16 as a signal EIZO_LVL indicating the received electric field strength in the video reception period excluding the horizontal blanking period.

  Next, a detailed configuration of the changeover switch SW will be described. In FIG. 5, the selector switch SW is connected to a decoder D1 that decodes a 3-bit signal S5 input from the switching controller SC into an 8-bit signal S51, and reception antennas A1 to A4. Of the signals Sa and Sb respectively connected to the switch SW11 that selects the switch SW11 and the receiving antennas A5 to A8, connected to the switch SW12 that selects any one of the switches SW11 and SW12, and output from the switches SW11 and SW12, respectively. The switch SW13 that selects and outputs one of them and the inverting circuit I1 that ensures the exclusive logic of the switch SW13 based on the most significant bit input to the decoder.

  The signal S5 is input to the decoder D1 as a 3-bit signal for selecting one of the eight receiving antennas A1 to A8. The 3-bit signal S5 is a signal ANT_SELECT [0], a signal ANT_SELECT [1], and a signal ANT_SELECT [2], and a signal indicating the most significant bit is a signal ANT_SELECT [2]. The decoder D1 decodes the 3-bit signal S5 into the 8-bit signal S51, outputs the lower 4-bit signal S51a to the switch SW11 that switches the lower-order receiving antennas A1 to A4, and receives the upper-order signal. The upper 4-bit signal S51b is output to the switch SW12 that switches the antennas A5 to A8. The switches SW11 and SW12 select one of the receiving antennas A1 to A8 according to the signals S51a and S51b, respectively. The switch SW13 selects one of the signals Sa and Sb output from the switches SW11 and SW12 based on the most significant bit signal ANT_SELECT [2]. Here, when the switch SW11 selects any one of the receiving antennas A1 to A4, the switch SW12 does not select the receiving antennas A5 to A8. However, in order to increase the selection accuracy, the inversion is performed. An inversion signal of the most significant bit signal ANT_SELECT [2] from the circuit I1 is input to perform exclusion processing. The signals of the receiving antennas A1 to A8 finally selected by the switch SW13 are output to the receiving circuit 11. Here, the receiving antennas A1 to An are described as eight receiving antennas A1 to A8. The antenna numbers of the receiving antennas A1 to A8 are identification information unique to each antenna, and “1” to “8” are “0” to “7” for information processing.

  Next, the synchronization period and the video reception period described above with reference to FIGS. 6 and 7, that is, the frame configuration of the radio signal, and the selection switching process of the receiving antennas A <b> 1 to An will be described. The radio signal sent from the capsule endoscope 3 is sent in units of frames. As shown in FIG. 6, this frame is an information body part including a synchronization period TS as an additional part including information for synchronization and an information body. As a video signal period TM. The synchronization period TS is a period corresponding to a preamble signal period for reception adjustment. The video signal period TM is a period for receiving a video signal. The video signal is a horizontal blanking period inserted between the video line period TH and the video line period TH in which the video line signal for each line is transmitted. And Th. In the horizontal blanking period Th, the dummy pulse P added by the dummy signal adding unit 22a is inserted as described above. In addition to the horizontal video signal itself, the video signal period TM can include a control signal necessary for receiving the video signal. Note that the synchronization period and the video reception period may be provided as independent periods, or may be provided as overlapping periods.

  Each frame is sent as shown in FIG. 7, and there may be a no-signal state between the frames, or each frame may be sent continuously. Considering the effective use of the battery of the capsule endoscope 3, the frame period TT of the frame transmission is shortened in an imaging region to be noticed or a region where the capsule endoscope 3 is moving fast, and the frame cycle TT is short or long. Is flexibly adjusted.

  As shown in FIG. 7, in the nth frame (n), the receiving antenna is switched at the timing tc in the synchronization period TS, and the receiving antenna is switched between the video line period TH and the horizontal blanking period Th. Can be switched. Here, the video receiving antenna is a receiving antenna that receives in the period TSH after the timing tc in the synchronization period TS, the video line period TH of the first line, and each video line period TH after the second line. Say. The strength receiving antenna refers to a receiving antenna that is received in the period TSS before the timing tc in the synchronization period TS and in each horizontal blanking period Th. The selection control unit C1 measures the received electric field strength during the period of switching to the strength receiving antenna, and uses the receiving antenna having the largest receiving electric field strength including the received electric field strength of the current video receiving antenna as the next video receiving antenna. Select and switch as a receiving antenna in the switching period, and select an intensity receiving antenna excluding at least the immediately preceding video receiving antenna in the period for switching to the next intensity receiving antenna. By such repetition, the receiving antenna having the highest received electric field strength at that time is selected as the video receiving antenna.

  It should be noted that the timing for selecting the receiving antenna with the highest received electric field strength may be selected after a predetermined number of received electric field strength measurements, and the video receiving antenna selected last time may be selected during that time. For example, the video receiving antenna may be selected and determined for each frame. In this case, the video receiving antenna selected and determined in frame (n) is used as the video receiving antenna for the next frame (n + 1).

  Further, in FIG. 7, the received electric field strength measurement is performed once in the period TSS before the timing tc in the synchronization period TS and in each horizontal blanking period Th. Reception field strength measurement may be performed, and in this case, reception field strength measurement of a plurality of different reception antennas may be performed. Note that timings to to t2 and tt1 to tt3 are pulses generated by the pulse generator 15a. Here, the received electric field strength is measured in the horizontal blanking period Th to which the dummy pulse P is added. Even if the dummy pulse is added to all the horizontal blanking periods Th, all the horizontal blanking periods Th are measured. However, it is not necessary to measure the received electric field strength.

  Note that the antenna switching between the video line period TH and the horizontal blanking period Th can use the synchronization of horizontal blanking, so that switching with high accuracy is possible.

  In this embodiment, a reception pulse strength measurement dummy pulse P is added to the horizontal blanking period Th in the video signal period TM, and reception for selecting a video receiving antenna is performed within the horizontal blanking period Th having a long total period. Since the electric field strength measurement is performed, the optimum video receiving antenna having the maximum received electric field strength can be selected with high accuracy and fineness.

  In the above-described embodiment, antenna switching is performed at timing tc within the synchronization period TS. However, sufficient reception field strength measurement for selecting an optimal video reception antenna should be performed only in the horizontal blanking period Th. Therefore, as shown in FIG. 8, it is preferable to delete the synchronization period TSS and set the synchronization period TSH only for the period TSH necessary for synchronization of video signal reception. In this case, the synchronization period can be shortened, and as a result, the transmission time in the frame is shortened, so that the power saving of the capsule endoscope 3 can be achieved.

1 is a schematic diagram showing an overall configuration of a wireless in-vivo information acquiring system according to an embodiment of the present invention. It is a block diagram which shows the structure of the capsule type endoscope 3 shown in FIG. It is a block diagram which shows the structure of the receiver shown in FIG. FIG. 4 is a block diagram showing a detailed configuration of a sample and hold circuit shown in FIG. 3. FIG. 4 is a block diagram illustrating a detailed configuration of a changeover switch illustrated in FIG. 3. It is a figure which shows the frame format of the radio signal sent from the capsule type endoscope shown in FIG. 3 is a time chart showing reception electric field strength measurement and antenna switching processing by the reception apparatus shown in FIG. 1. 7 is a time chart showing a modification of received electric field strength measurement and antenna switching processing by the receiving apparatus shown in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Subject 2 Reception apparatus 2a Reception jacket 2b External apparatus 3 Capsule endoscope 4 Display apparatus 5 Portable recording medium 11 Reception circuit 12 Signal processing circuit 13 Memory | storage part 14 Display part 15 Sample hold circuit 15a Pulse generator 15b Intensity reception Sample hold circuit 15c Video reception sample hold circuit 16 A / D conversion unit 17 Power supply unit 19 LED
20 LED drive circuit 21 CCD
DESCRIPTION OF SYMBOLS 22 Signal processing circuit 22a Dummy signal addition part 23 RF transmission unit 24 Transmission antenna part 25 CCD drive circuit 26 System control circuit 27 Imaging circuit 30 Power switch circuit 31 Signal detection circuit 32 Switch control circuit 33 Power switch 34 Drive control part 35 Sensor part 50 Magnet C Control Unit C1 Selection Control Unit SC Switching Control Unit D1 Decoder I1 Inversion Circuit SW Switch SW11, SW12, SW13 Switch N1 Strength Reception Antenna Number Information N2 Video Reception Antenna Number Information A1 to An Reception Antenna

Claims (7)

Reception for receiving a radio signal transmitted from a moving transmission apparatus and having a frame structure having at least an information body including an information body and an additional unit including information for synchronization using a plurality of antennas In the device
The reception electric field strength of each antenna is detected by sequentially switching each antenna in the empty portion of the wireless signal in which a dummy signal for measuring reception intensity is added to the empty portion in the information main body where the arrangement position is determined in advance. And a control unit that performs control to switch to the antenna that has detected the highest received electric field strength and to cause the antenna to receive a radio signal of the information main body portion other than the empty portion.   The receiving apparatus according to claim 1, wherein the control unit sequentially switches each antenna including a part of the adding unit to detect a received electric field strength of each antenna.   3. The receiving apparatus according to claim 1, wherein the control unit measures reception electric field strengths of a plurality of antennas in at least a part of an empty part of the information main body part and a part of the additional part. .   The receiving apparatus according to claim 1, wherein the information main body is a video signal, and the empty portion is a horizontal blanking period. In a transmission device that transmits a video signal obtained by imaging as a radio signal and causes a reception device including a plurality of antennas to receive the video signal.
In a horizontal blanking period in the video signal, a dummy signal for measuring a received electric field strength that detects a received electric field strength at each antenna by sequentially switching and receiving each antenna of the receiver is transmitted. A transmitter characterized by the above. In a transmission / reception system having a transmission device that transmits a video signal obtained by imaging as a wireless signal and a reception device that receives the video signal using a plurality of antennas,
The transmitter is
A dummy signal adding means for adding and transmitting a dummy signal during a horizontal blanking period in the video signal;
The receiving device is:
Each antenna is sequentially switched during the horizontal blanking period to detect the received electric field strength at each antenna from the dummy signal, and the antenna that detects the largest received electric field strength is switched to the antenna other than the horizontal blanking period. A transmission / reception system comprising control means for performing control for receiving a video signal.   The transmission / reception system according to claim 6, wherein the control means detects the received electric field intensity by sequentially switching each antenna including a synchronization signal period for measuring the received electric field intensity added to the video signal.

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