JP2010093543A - Image pickup device, transmission method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pickup device composed of a CCU and a CHU which are connected via a cable, which realizes a high image quality of captured image data while improving the degree of freedom in arranging the CCU and CHU. <P>SOLUTION: A clock signal generation section 26 generates a clock signal and supplies it to a CHU 13 through a clock signal transmission path 12f. A cable length detection section 27 detects a cable length of a cable 12. A timing control section 29 advances a phase of a synchronization signal outputted by an image data processing section 34 to output the signal to a synchronization signal transmission section 31. A time for which a phase of the synchronization signal is advanced by the timing control section 29 is determined by acquiring a delay time and the like corresponding to a cable length notified from the cable length detection section 27, from a reference table 30. The present invention can be applied to an industrial camera composed of the CCU and CHU connected through a cable. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging device, a transmission method, and a program, and in particular, for example, in an industrial camera, a camera head unit including an imaging element such as a CMOS (Complementary Metal-Oxide Semiconductor), and image data obtained as a result of imaging The present invention relates to an imaging apparatus, a transmission method, and a program that are suitable for use when a camera control unit that records, edits, displays, and controls a camera head unit is connected by a long and thin cable.

  2. Description of the Related Art Conventionally, there is an imaging apparatus configured as shown in FIG. 1 as an industrial camera employed in, for example, a medical examination apparatus or a surgical apparatus (for example, see Patent Document 1).

  That is, FIG. 1 shows an external view of an imaging device as a conventional industrial camera. The imaging apparatus 1 is configured by connecting a camera control unit (hereinafter referred to as CCU) 2 and a camera head unit (hereinafter referred to as CHU) 4 by a cable 3.

  The CCU 2 controls the CHU 4, records, edits and displays image data captured by the CHU 4, and outputs it externally.

  The cable 3 combines a transmission path for transmitting control information from the CCU 2 to the CHU 4, a supply path for supplying power from the CCU 2 to the CHU 4, a transmission path for transmitting image data from the CHU 4 to the CCU 2, and the like. The cable 3 has a diameter of about 10 to 15 mm, for example, and its length is determined according to the application.

  The CHU 4 incorporates an imaging device such as a CMOS, and transmits image data obtained as a result of imaging to the CCU 2 via the cable 3.

  In such an industrial camera, it is desired to improve the image quality of captured image data, and the cable 3 is also required to be extended and reduced in diameter in order to improve the degree of freedom of arrangement of the CCU 2 and the CHU 4. ing.

JP 2004-101683 A

  When the cable length is extended, it takes a long time to supply image data from the CHU 4 to the CCU 2 in response to a request from the CCU 2.

  In addition, as a method for improving the image quality of captured image data, a method of capturing image data of two systems (0ch (channel) and 1ch) with the CHU 4 and supplying the image data to the CCU 2 is conceivable. Here, the image data for two systems means data obtained by imaging the same subject under different conditions.

  For example, a standard quality image can be obtained from image data for one system, and a high quality image can be obtained from image data for two systems. Further, for example, an interlaced image can be obtained from image data for one system, and a progressive image can be obtained from image data for two systems.

  As described above, when image data for two systems is transmitted from the CHU 4 to the CCU 2, the time until it is supplied to the CCU 2 differs between systems (between 0ch and 1ch). Will occur. In particular, the delay amount changes depending on the cable length of the cable 3 to the highest extent, so that it is necessary to correct the delay according to the cable length.

  The present invention has been made in view of such a situation. In an imaging apparatus including a CCU and a CHU connected via a cable, the CCU and the CHU are realized while achieving high image quality of captured image data. The degree of freedom of arrangement is improved.

  An imaging apparatus according to a first aspect of the present invention is an imaging apparatus including a CCU and a CHU connected via a cable. The CCU determines a cable length of the cable as a transmission path for image data and an image synchronization signal. Detecting means for detecting, generating means for generating the image synchronization signal for acquiring the image data from the CHU, control means for controlling the transmission timing of the image synchronization signal based on at least the cable length, and control In accordance with the transmission timing, the phase of the generated image synchronization signal is advanced and transmitted to the CHU via the cable, and according to the transmitted image synchronization signal, from the CHU to the Image data receiving means for receiving the image data supplied via a cable, and the CHU transmits from the CCU via the cable Image synchronization signal receiving means for receiving the received image synchronization signal, image data generating means for performing imaging in accordance with the received image synchronization signal, and generating the image data as an imaging result, and the generated image data And image data transmitting means for transmitting to the CCU via the cable.

  The control means controls transmission timing of the image synchronization signal based on transmission time in the cable length, processing by the image synchronization signal transmission means, processing by the image synchronization signal reception means, and processing by the image data transmission means. can do.

  In the imaging apparatus according to the first aspect of the present invention, the CCU further includes buffering means for buffering the received image data, and the control means is buffered in the buffering means. Image data read timing can also be controlled.

  The image data generation unit generates a plurality of channels of image data, and the image data transmission unit transmits the plurality of channels of image data to the CCU via a plurality of image data transmission paths provided in the cable. The buffering means can distinguish and buffer the image data of the plurality of channels.

  The detection means can detect the cable length based on information recorded in a connector of the cable.

  A transmission method according to a first aspect of the present invention is a transmission method of an imaging apparatus composed of a CCU and a CHU connected via a cable. The transmission method of the cable as a transmission path for image data and an image synchronization signal by the CCU. A detection step of detecting a cable length, a generation step of generating the image synchronization signal for acquiring the image data from the CHU, and a control step of controlling the transmission timing of the image synchronization signal based on at least the cable length In accordance with the transmission timing to be controlled, the phase of the generated image synchronization signal is advanced and transmitted to the CHU via the cable, and according to the transmitted image synchronization signal, the image synchronization signal An image data receiving step for receiving the image data supplied from the CHU via the cable; An image synchronization signal receiving step for receiving the image synchronization signal transmitted from the CCU via a cable; and an image data generation step for performing imaging according to the received image synchronization signal and generating the image data as an imaging result; An image data transmission step of transmitting the generated image data to the CCU via the cable.

  A program according to the first aspect of the present invention is a program for controlling an image pickup apparatus composed of a CCU and a CHU connected via a cable, and is used as a transmission path for image data and an image synchronization signal by the CCU. A detection step for detecting a cable length of the cable, a generating means for generating the image synchronization signal for acquiring the image data from the CHU, and a transmission timing of the image synchronization signal based on at least the cable length A control step for transmitting, an image synchronization signal transmission step for transmitting a phase of the generated image synchronization signal to the CHU via the cable in accordance with the transmission timing to be controlled, and the transmitted image synchronization signal. In response, the image data receiving step of receiving the image data supplied from the CHU via the cable, and the CHU An image synchronization signal receiving step for receiving the image synchronization signal transmitted from the CCU via the cable, and image data for performing imaging according to the received image synchronization signal and generating the image data as an imaging result The computer of the imaging apparatus is caused to execute a process including a generation step and an image data transmission step of transmitting the generated image data to the CCU via the cable.

  In the first aspect of the present invention, the cable length of a cable as a transmission path for image data and an image synchronization signal is detected by the CCU, and an image synchronization signal for acquiring image data from the CHU is generated. The transmission timing of the image synchronization signal is controlled based on the length, and in accordance with this control, the phase of the generated image synchronization signal is advanced and transmitted to the CHU via the cable. Further, imaging is performed by the CHU according to the image synchronization signal transmitted from the CCU, image data is generated as an imaging result, and the generated image data is transmitted to the CCU via a cable.

  An imaging apparatus according to a second aspect of the present invention is an imaging apparatus including a CCU and a CHU connected via a cable. The CCU generates a clock signal and transmits the clock signal to the CHU via the cable. Means, generating means for generating an image synchronization signal for acquiring the image data from the CHU, and image synchronization signal transmitting means for transmitting the generated image synchronization signal to the CHU via the cable; Image data receiving means for receiving the image data supplied from the CHU via the cable in response to the transmitted image synchronization signal, the CHU being transmitted from the CCU via the cable A clock signal receiving means for receiving the clock signal and generating a clock signal for CHU; and an image receiving the image synchronization signal transmitted from the CCU via the cable. A signal receiving unit; an image data generating unit configured to perform imaging in accordance with the CHU clock signal and the received image synchronization signal; and generate the image data as an imaging result; and the generated image data to the cable Image data transmitting means for transmitting to the CCU via

  The image data generation unit generates a plurality of channels of image data, and the image data transmission unit transmits the plurality of channels of image data to the CCU via a plurality of image data transmission paths provided in the cable. can do.

  A transmission method according to a second aspect of the present invention is a transmission method of an imaging apparatus including a CCU and a CHU connected via a cable, wherein a clock signal is generated by the CCU and is transmitted to the CHU via the cable. A generation step for transmitting, a generation step for generating an image synchronization signal for acquiring the image data from the CHU, and an image synchronization signal transmission for transmitting the generated image synchronization signal to the CHU via the cable. An image data receiving step of receiving the image data supplied from the CHU via the cable according to the transmitted image synchronization signal, and the CHU being transmitted from the CCU via the cable. A clock signal receiving step for receiving the clock signal and generating a clock signal for CHU, and transmitted from the CCU via the cable. An image synchronization signal receiving step for receiving the image synchronization signal, an image data generation step for performing imaging according to the CHU clock signal and the received image synchronization signal, and generating the image data as an imaging result, and generation An image data transmission step of transmitting the image data to the CCU via the cable.

  In the second aspect of the present invention, a clock signal is generated by the CCU and transmitted to the CHU via a cable. Also, an image synchronization signal for acquiring image data from the CHU is generated and transmitted to the CHU via a cable. In addition, a CHU clock signal is generated from the transmitted clock signal by the CHU, imaging is performed according to the generated CHU clock signal and the received image synchronization signal, and the image data is generated as an imaging result. Then, the generated image data is transmitted to the CCU via the cable.

According to the first aspect of the present invention, in an imaging device composed of a CCU and a CHU connected via a cable, the degree of freedom of arrangement of the CCU and the CHU is achieved while realizing high image quality of the image data to be captured. Can be improved.
wear.

  According to the second aspect of the present invention, in an imaging device composed of a CCU and a CHU connected via a cable, the degree of freedom of arrangement of the CCU and the CHU is achieved while realizing high image quality of the image data to be captured. Can be improved.

  Hereinafter, the best mode for carrying out the invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.

[Configuration example of imaging device]
FIG. 2 shows an example of the configuration of an imaging apparatus according to an embodiment of the present invention. This imaging device 10 is composed of a CCU 11 and a CHU 13 connected to the CCU 11 by a cable 12 in the same manner as the conventional imaging device 1 shown in FIG.

  The CCU 11 supplies power and a clock signal to the CHU 13 via the cable 12 and transmits control information to control the CHU 13. The CCU 11 records, displays, and externally outputs image data transmitted from the CHU 13 via the cable 12.

  The CCU 11 includes a control unit 21, a power supply unit 25, a clock signal generation unit 26, a cable length detection unit 27, a control information communication unit 28, a timing control unit 29, and a synchronization signal transmission unit 31. Furthermore, the CCU 11 includes an image data receiving unit 32, a FIFO 33, an image data processing unit 34, an image data output unit 35, an image display unit 36, and an image recording unit 37.

  The control unit 21 includes a CPU 22, a RAM 23, and a ROM 24. The CPU 22 loads the control program recorded in the ROM 24 in advance into the RAM 23 and executes it, thereby controlling each unit of the CCU 11.

  The power supply unit 25 supplies drive power to each unit of the CCU 11 using an AC power supply or a battery (both not shown) as a power supply, and also supplies drive power to the CHU 13 via the power supply path 12g of the cable 12.

  The clock signal generation unit 26 generates a clock signal, supplies the generated clock signal to each unit of the CCU 11, and supplies the generated clock signal to the CHU 13 through the clock signal transmission path 12 f of the cable 12.

  The cable length detection unit 27 detects the cable length of the cable 12 connecting the CCU 11 and the CHU 13 and notifies the timing control unit 29 of the detection result. As a specific method for detecting the cable length, the cable length is detected by reading information indicating the cable length from the connector of the cable 12.

  The control information communication unit 28 communicates various control information with the CHU 13 via the high-speed signal transmission paths 12 d and 12 e of the cable 12.

  The timing control unit 29 advances the phase of the synchronization signal (frame synchronization signal, vertical synchronization signal, and horizontal synchronization signal) output from the image data processing unit 34 and outputs it to the synchronization signal transmission unit 31. The timing control unit 29 controls the read timing of the image data held in the FIFO 33. About the time (henceforth precedent time) which advances the phase of a synchronizing signal by the timing control part 29, the delay time etc. corresponding to the cable length notified from the cable length detection part 27 are acquired from the reference table 30, and are determined. (Details will be described later).

  The reference table 30 includes a transmission variable (delay time) corresponding to each cable length of the cable 12, a time required to transmit image data inside the CCU 11, and a time required to transmit image data inside the CHU 13. Is recorded in advance.

  The synchronization signal transmission unit 31 transmits the synchronization signal from the timing control unit 29 to the CHU 13 via the high-speed signal transmission path 12 c of the cable 12.

  The image data receiving unit 32 receives 0ch image data from the CHU 13 via the ultrahigh-speed signal transmission path 12a of the cable 12, and 1ch image data from the CHU13 via the ultrahigh-speed signal transmission path 12b of the cable 12. Receive. Further, the image data receiving unit 32 outputs the received 0ch image data to the FIFO 33a to control the writing timing, and outputs the received 1ch image data to the FIFO 33b to control the writing timing.

  The FIFO 33 is divided into a 0ch FIFO 33a and a 1ch FIFO 33b. Further, the FIFO 33a and the FIFO 33b are divided into three corresponding to the three primary colors RGB.

  The image data processing unit 34 performs predetermined image processing on the image data output from the FIFO 33 and outputs the image data to the image data output unit 35. The image data output unit 35 supplies the image data after the image processing to the image display unit 36 and the image recording unit 37. The image data output unit 35 outputs the image data after image processing to the outside of the imaging device 10.

  The image display unit 36 displays an image based on the image data from the image data output unit 35 on a display (not shown). The image recording unit 37 encodes the image data from the image data output unit 35 according to a predetermined method, and records the encoded signal obtained as a result on a recording medium (not shown).

  The cable 12 is attachable to and detachable from the CCU 11 and the CHU 13 and has a diameter of about 7 mm. There are several types of cable lengths (for example, 5, 10, 15, 20 m) depending on the application. It is prepared. In the connector of the cable 12, information indicating the cable length is recorded at the manufacturing stage (details will be described later).

  The cable 12 includes ultra-high-speed signal transmission paths 12a and 12b for transmitting image data, a high-speed signal transmission path 12c for transmitting a synchronization signal, high-speed signal transmission paths 12d and 12e for transmitting control information, a clock signal transmission path 12f, And a power supply path 12g.

  The ultra high-speed signal transmission path 12a transmits 0ch image data output from the CHU 13 to the image signal receiving unit 32 of the CCU 11 at, for example, about several Gbps. The ultra high-speed signal transmission path 12b transmits the 1ch image data output from the CHU 13 to the image signal receiving unit 32 of the CCU 11 at, for example, about several Gbps.

  Note that the cable lengths of the ultrahigh-speed signal transmission path 12a and the ultrahigh-speed signal transmission path 12b do not necessarily match due to a twist or the like in the cable 12. This minute difference in cable length affects the difference in transmission time between 0ch image data and 1ch image data.

  The high-speed signal transmission path 12c transmits a synchronization signal output from the synchronization signal device unit 31 of the CCU 11 to the CHU 13 at, for example, about 100 Mbps. The high-speed signal transmission path 12d transmits the control information transmitted from the control information communication unit 28 of the CCU 11 to the CHU 13 at, for example, about 150 Mbps. The high-speed signal transmission path 12e transmits the control information that the CHU 13 transmits to the control information communication unit 28 of the CCU 11 at, for example, about 150 Mbps.

  The clock signal transmission path 12 f transmits the 74 MHz clock signal generated by the clock signal generation unit 26 of the CCU 11 to the CHU 13. The power supply path 12g transmits drive power supplied from the power supply unit 25 of the CCU 11 to the CHU 13.

  The CHU 13 captures images according to the control from the CCU 11 based on the driving power and the clock signal supplied from the CCU 11, and the 0ch and 1ch image data obtained as the imaging results are transmitted through the ultrahigh-speed signal transmission paths 12 a and 12 b of the cable 12. And output to the CCU 11.

  The CHU 13 includes a power control unit 51, a clock signal reception unit 52, a control information communication unit 53, a synchronization signal reception unit 54, a CMOS image sensor 55, a defect correction ROM 58, and an image data transmission unit 59.

  The power control unit 51 supplies driving power supplied from the power supply unit 25 of the CCU 11 via the power supply path 12 g to each unit of the CHU 13. The clock signal receiving unit 52 receives a clock signal transmitted from the clock signal generation unit 26 of the CCU 11 via the clock signal transmission path 12f, divides the received clock signal to the operating frequency of the CHU 13, and transmits a control information communication unit 53.

  The control information communication unit 53 receives control information transmitted from the control information communication unit 28 of the CCU 11 via the high-speed signal transmission path 12d. The control information communication unit 53 controls the CMOS image sensor 55 according to the control information from the CCU 11 based on the clock signal from the clock signal receiving unit 52 and the synchronization signal from the synchronization signal receiving unit 54. Further, the control information communication unit 53 generates control information to be notified to the CCU 11, and transmits the control information to the control information communication unit 28 of the CCU 11 via the high-speed signal transmission path 12e.

  The synchronization signal reception unit 54 receives the synchronization signal from the synchronization signal transmission unit 31 of the CCU 11 via the high-speed signal transmission path 12 c and supplies the received synchronization signal to the control information communication unit 53.

  Among the three primary colors RGB, the CMOS image sensor 55 includes an image sensor 56R and a temperature sensor 57R corresponding to R, an image sensor 56G and a temperature sensor 57G corresponding to G, an image sensor 56B and a temperature sensor 57B corresponding to B, and a defect. It consists of a correction ROM 58. The CMOS image sensor 55 generates 0ch and 1ch image data and supplies them to the image data transmission unit 59.

  The image data transmission unit 59 receives 0ch image data from the CMOS image sensor 55 via the ultra high speed signal transmission path 12a and 1ch image data from the CMOS image sensor 55 via the ultra high speed signal transmission path 12b. The data is transmitted to the image data receiving unit 32.

[Overview of image pickup device operation]
FIG. 3 is a block diagram illustrating some of the components of the imaging apparatus 10 that are necessary for explaining the outline of the operation of the imaging apparatus 10.

  That is, in the imaging apparatus 10, the image data processing unit 34 generates a synchronization signal corresponding to the image data transmitted from the CHU 13 and outputs the synchronization signal to the timing control unit 29. The timing control unit 29 takes the transmission delay of the image data into consideration and advances the phase of this synchronization signal and outputs it to the synchronization signal transmission unit 31. The synchronization signal transmission unit 31 multiplexes the synchronization signals (frame synchronization signal F, vertical synchronization signal V, and horizontal synchronization signal H), and transmits them to the synchronization signal reception unit 54 of the CHU 13 via the high-speed signal transmission path 12c.

  The synchronization signal receiver 54 of the CHU 13 receives the multiplexed synchronization signal, demultiplexes (separates) it into the frame synchronization signal F, the vertical synchronization signal V, and the horizontal synchronization signal H, and supplies it to the CMOS image sensor 55. . In accordance with the supplied synchronization signal, the CMOS image sensor 55 outputs image data (CH0R, CH0G, CH0B) and strobe (STRB) signals for each color of 0ch, and image data (CH1R, CH1G, CH1B) and strobe signals for each color of 1ch. Is output to the image data transmission unit 59. The image data transmission unit 59 multiplexes the image data (CH0R, CH0G, CH0B) of each color of 0ch and the strobe signal, and transmits the multiplexed data to the image data reception unit 32 of the CCU 11 via the ultrahigh-speed signal transmission path 12a. Further, the image data transmission unit 59 multiplexes the image data (CH1R, CH1G, CH1B) of each color of 1ch and the strobe signal, and transmits them to the image data reception unit 32 of the CCU 11 via the ultrahigh-speed signal transmission path 12b.

  The image data receiving unit 32 of the CCU 11 receives the multiplexed image data of each color of 0ch, demultiplexes (separates) the image data of each color and the strobe signal, and outputs the image data of each color (CH0R, CH0G, CH0B). ) To the FIFO 33a, and buffering is performed by a write command according to the strobe signal. The image data receiving unit 32 receives the multiplexed image data of each color of 1ch, demultiplexes (separates) the image data of each color and the strobe signal, and outputs the image data of each color (CH1R, CH1G, CH1B). ) To the FIFO 33b, and buffering is performed by a write command in accordance with the strobe signal.

  Thereafter, the timing control unit 29 simultaneously outputs a read command to the 0ch FIFO 33a and the 1ch FIFO 33b, and causes the image data processing unit 34 to output the image data buffered respectively.

[Detailed operation of the imaging device]
Next, a series of operations of the imaging apparatus 10 will be described in detail with reference to timing charts shown in FIGS.

  However, in FIGS. 4 to 6, the CCU 11 includes the control unit 21 as hardware, the control unit 21 as software realized by the CPU 22 executing the control program, the image data processing unit 34, and the power supply unit. 25 and others (among the components of the CCU 11, the control unit 21 as hardware, the control unit 21 as software realized by the CPU 22 executing the control program, the image data processing unit 34, and the power supply unit) Each of the processes is shown by being divided into those other than 25). Each process is shown by dividing the CHU 13 into a CM0S image sensor 55 and others (components of the CHU 13 other than the CM0S image sensor 55).

  When a power button provided in the control unit 21 is turned on, power is supplied to each unit of the CCU 11 by the power supply unit 25, and the CPU 22 executes a control program to activate the control unit 21 as software. Further, the reset of the image data processing unit 34 and the power supply unit 25 is released.

  Next, the power supply unit 25 requests the cable length detection unit 27 to detect the cable length of the cable 12. In response to this request, the cable length detection unit 27 detects the cable length of the cable 12 and notifies the timing control unit 29 of the detection, and notifies the power supply unit 25 of the completion of the detection of the cable length.

  Next, the power supply unit 25 requests the control information communication unit 28 to detect whether or not the CHU 13 is connected to the end of the cable 12. In response to this request, the control information communication unit 28 detects the presence of the CHU 13 and notifies the power supply unit 25 of the detection result. As a result of this detection, when the CHU 13 does not exist at the end of the cable 12, a series of processing is terminated at this point.

  On the other hand, when the CHU 13 exists at the end of the cable 12, the power supply unit 25 notifies the control unit 21 that the CHU 13 exists, and then supplies the drive power to the CHU 13 via the power supply path 12g. Start. Further, the clock signal supply unit 26 supplies the generated clock signal to the CHU 13 via the clock signal transmission path 12f. When the driving power and the clock signal are supplied, the rest of the CCU 11 and other than the CMOS image sensor 55 of the CHU 13 release the reset and execute the configuration. The CMOS image sensor 55 releases the reset.

  Thereafter, the control unit 21 as software controls the image data processing unit 34 to acquire 0ch and 1ch image data, temperature sensor values, and defect correction ROM information from the CMOS image sensor 55. In response to this control, the image data processing unit 34 generates control information for requesting the CMOS image sensor 55 to transmit 0ch and 1ch image data, temperature sensor values, and defect correction ROM information, and performs control information communication. To the unit 28. The control information communication unit 28 packetizes the control information input from the image data processing unit 34 as shown in FIG. 7, for example, and then performs predetermined data packing processing (for example, parallel serial conversion processing, NRZ or NRZI, etc. (Encoding process, scramble process, CRC process, etc.) are performed and transmitted to the control information communication unit 53 of the CHU 13 via the high-speed signal transmission path 12d.

  The control information communication unit 53 of the CHU 13 acquires the temperature sensor value and the defect correction ROM information from the CMOS image sensor 55 according to the received control information, and generates control information. Further, the control information communication unit 53 packetizes the generated control information as shown in FIG. 8, for example, and then performs predetermined data packing processing (for example, scrambling processing, encoding processing such as NRZ or NRZI, CRC processing, Parallel serial conversion processing) is performed, and is transmitted to the control information communication unit 28 of the CCU 11 via the high-speed signal transmission path 12e. The control information communication unit 28 of the CCU 11 decodes the received control information on which data packing processing is performed and supplies the decoded control information to the image data processing unit 34.

  Next, the image data processing unit 34 generates a synchronization signal and outputs it to the timing control unit 29. The timing control unit 29 advances the phase of the input synchronization signal and outputs it to the synchronization signal transmission unit 31. The synchronization signal transmission unit 31 multiplexes the synchronization signal whose phase has been advanced, packetizes it as shown in FIG. 9, for example, and then performs predetermined data packing processing (for example, code such as parallel serial conversion processing, NRZ or NRZI). Processing, scramble processing, CRC processing, etc.), and transmits to the synchronization signal receiving unit 54 of the CHU 13 via the high-speed signal transmission path 12c. The synchronization signal receiver 54 of the CHU 13 demultiplexes (separates) the received multiplexed synchronization signal and supplies it to the CMOS image sensor 55.

  In accordance with the supplied synchronization signal, the CMOS image sensor 55 outputs image data (CH0R, CH0G, CH0B) and strobe (STRB) signals for each color of 0ch, and image data (CH1R, CH1G, CH1B) and strobe signals for each color of 1ch. Is output to the image data transmission unit 59. The image data transmission unit 59 multiplexes the 0ch image data (CH0R, CH0G, CH0B) and the strobe signal into packets, and performs predetermined data packing processing (for example, scrambling processing, encoding processing such as NRZ or NRZI, CRC processing, parallel serial conversion processing, etc.) are performed and transmitted to the image data receiving unit 32 of the CCU 11 via the ultra high-speed signal transmission path 12a. Similarly, the image data (CH1R, CH1G, CH1B) of each color of 1ch is transmitted to the image data receiving unit 32 of the CCU 11 via the ultrahigh-speed signal transmission path 12b.

  The image data receiving unit 32 of the CCU 11 receives the multiplexed image data of each color of 0ch, demultiplexes (separates) the image data of each color and the strobe signal, and outputs the image data of each color (CH0R, CH0G, CH0B). ) To the FIFO 33a, and buffering is performed by a write command according to the strobe signal. The image data receiving unit 32 receives the multiplexed image data of each color of 1ch, multiplexes and demultiplexes (separates) the image data of each color and the strobe signal, and outputs the image data of each color (CH1R, CH1G). , CH1B) is supplied to the FIFO 33b, and buffering is performed by a write command in accordance with the strobe signal.

  Thereafter, the timing control unit 29 simultaneously outputs a read command to the 0ch FIFO 33a and the 1ch FIFO 33b, and causes the image data processing unit 34 to output the image data buffered respectively.

  The image data processing unit 34 performs predetermined image processing on the image data input from the FIFO 33. The image data of the predetermined image processing is displayed on the display by the image display unit 36, recorded on a recording medium by the image recording unit 37, or externally output by the image data output unit 35. Above, description of a series of operation | movement of the imaging device 10 is complete | finished.

[Image data transmission delay and countermeasures]
Next, a time until a synchronization signal is output from the image data processing unit 34 and image data is input to the image data processing unit 34 accordingly, that is, a transmission delay of the image data and a countermeasure for eliminating the transmission delay. Will be described.

  FIG. 10 shows the cause of transmission delay of image data. FIG. 11 shows how to deal with transmission delay. FIG. 12 shows the concept that the transmission delay is absorbed by the FIFO 33.

  That is, the synchronization signal output from the image data processing unit 34 is delayed by the multiplexing process in the synchronization signal transmitting unit 31 of the CCU 11, delayed depending on the cable length of the high-speed signal transmission path 12 c, and supplied to the CHU 13. . Further, it is delayed by the demultiplexing (separation) processing in the synchronization signal receiver 54 of the CHU 13 and supplied to the CMOS image sensor 55.

  The image data of each color of 0ch and 1ch output from the CMOS image sensor 55 according to the synchronization signal is delayed by the amount of multiplexing processing by the image data transmission unit 59.

  The delay time up to this point is common to 0ch and 1ch. The common delay time is compensated by the timing control unit 29 by advancing the phase of the synchronization signal output from the image data processing unit 34.

  The multiplexed image data of 0ch and 1ch is transmitted through the ultrahigh-speed signal transmission lines 12a and 12b, but is delayed depending on the cable length of the ultrahigh-speed signal transmission lines 12a and 12b. Further, the image data of 0ch and 1ch are delayed by the demultiplexing (separation) process in the image data receiving unit 32.

  However, since the cable lengths of the ultrahigh-speed signal transmission lines 12a and 12b do not necessarily match due to the twist of the cable or the like, the delay time is not included in the 0ch and 1ch image data when the image data receiving unit 32 receives them. Variations can occur. The delay time that may cause the variation between 0ch and 1ch is absorbed by the timing control unit 29 controlling the read timing of the FIFO 33.

  As described above, the delay time common to 0ch and 1ch among the delay times of the image data is compensated by the timing control unit 29 by advancing the phase of the synchronization signal output from the image data processing unit 34. In addition, the delay time that may vary between 0ch and 1ch is absorbed by controlling the read timing of the FIFO 33 by the timing control unit 29.

  FIG. 13 is a flowchart for explaining a main process for dealing with a transmission delay of image data. This main process is started before the synchronization signal is output from the image data processing unit 34 in the series of processes of the imaging apparatus 1 described above with reference to FIGS.

  In step S <b> 1, the timing control unit 29 acquires the cable length of the cable 12 from the cable length detection unit 27.

  In step S <b> 2, the timing control unit 29 refers to the reference table 30, so that the transmission variable (delay time) X, MUX constant (delay time) E, MUX constant F, and DeMux constant depending on the acquired cable length. (Delay time) G is acquired.

  FIG. 14 shows an example of the reference table 30. The reference table 30 holds transmission variables (delay time) X, MUX constant (delay time) E, MUX constant F, and DeMux constant (delay time) G corresponding to a plurality of cable lengths assumed in advance. Has been.

  The transmission variable X is a delay time that depends on the cable length. The MUX constant E is a fixed delay time required for the synchronization signal multiplexing process by the synchronization signal transmission unit 31. The MUX constant F is a fixed delay time required for multiplexing the image data of each color by the image data transmission unit 59. The DeMux constant (delay time) G is a fixed delay time required for the synchronization signal demultiplexing (separation) process by the synchronization signal receiving unit 54.

  In this embodiment, the transmission variable (delay time) X corresponding to the cable length is held as the reference table 30, but may be held as a function having the cable length as a variable. If held as a function, cable lengths other than the assumed length can be accommodated. The function may include the dielectric constant of the cable material as a variable other than the cable length.

  Further, the processes of steps S1 and S2 may be executed only when the cable 12 is newly connected to the CCU 11.

  Returning to FIG. In step S3, the timing control unit 29 advances the phase of the synchronization signal output from the image data processing unit 34 for the delay time common to 0ch and 1ch among the transmission delays of the image data (hereinafter referred to as synchronization signal). This is compensated for by the preceding output process. Further, the delay time that may cause variation between 0ch and 1ch is absorbed by controlling the read timing of the FIFO 33 by the timing control unit 29 (hereinafter referred to as reception variation absorption processing).

  FIG. 15 is a flowchart for explaining the synchronization signal preceding output process.

  In step S11, the timing control unit 29 adds the transmission variable X, MUX constant E, MUX constant F, and DeMux constant G acquired in step S2, and sets the addition result as the output preceding time. In step S <b> 12, the timing control unit 29 advances the phase of the synchronization signal output from the image data processing unit 34 by an amount corresponding to the output preceding time set in step S <b> 11 and outputs it to the synchronization signal transmission unit 31.

  FIG. 16 is a flowchart for explaining the reception variation absorbing process. In step S21, the timing control unit 29 transmits a read command to the FIFOs 33a and 33b at the same time, and causes the image data processing unit 34 to output the buffered image data.

  This is the end of the description of the transmission delay of the image data and the countermeasure.

[Detection of cable length]
FIG. 17 shows an example of a connector specification composed of 36 terminals of the cable 12. For example, 2-bit information can be held by appropriately short-circuiting the 17th terminal ID1 and the 18th terminal ID0 with the GND terminal in the connector for holding cable length information. Thereby, four types of cable lengths, such as 5m, 10m, 15m, or 20m, can be distinguished, for example.

  The cable length information is not held in the connector of the cable 12, but a predetermined pulse wave is transmitted from the CCU 11 to the CHU 13, and the CHU 13 that has received the pulse wave promptly returns the same pulse wave. The cable length may be detected based on the time required to return.

  As described above, according to the imaging apparatus 10 to which the present invention is applied, high-resolution image data is transmitted from the CHU 13 to the CCU 11 through the relatively long and thin cable 12 while suppressing deterioration in image quality. be able to. Note that the imaging apparatus 10 can be configured by using an existing imaging apparatus in which CCU and CHU are not separated. Therefore, the imaging device 10 can be manufactured at a reduced manufacturing cost.

  By the way, the above-described processing can be executed by hardware or can be executed by software. When the above-described processing is executed by software, a program constituting the software is installed from a program recording medium and executed on a computer incorporated in dedicated hardware.

  The program executed by the computer may be a program that is processed in time series in the order described in this specification, or in parallel or at a necessary timing such as when a call is made. It may be a program for processing.

  The program may be processed by a single computer, or may be distributedly processed by a plurality of computers. Furthermore, the program may be transferred to a remote computer and executed.

  The embodiment of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

It is an external view of an imaging device composed of CCU and CHU. It is a block diagram which shows the structural example of the imaging device to which this invention is applied. It is a figure for demonstrating the operation | movement outline | summary of an imaging device. It is a timing chart explaining a series of processings of an imaging device. It is a timing chart explaining a series of processings of an imaging device. It is a timing chart explaining a series of processings of an imaging device. It is a figure which shows an example of the data structure of the control information transmitted from CCU to CHU. It is a figure which shows an example of the data structure of the control information transmitted to CCU from CHU. It is a figure which shows an example of the data structure of the synchronizing signal transmitted from CCU to CHU. It is a figure explaining the factor of transmission delay of image data. It is a figure explaining the countermeasure to the transmission delay of image data. It is a figure explaining operation | movement of FIFO as a countermeasure to a transmission delay. It is a flowchart explaining a main process. It is a figure which shows an example of a reference table. It is a flowchart explaining a synchronous signal preceding output process. It is a flowchart explaining a reception variation absorption process. It is a figure which shows an example of the connector specification of a cable.

Explanation of symbols

  10 imaging device, 11 CCU, 12 cable, 13 CHU, 21 control unit, 25 power supply unit, 26 clock signal generation unit, 27 cable length detection unit, 28 control information communication unit, 29 timing control unit, 30 reference table, 31 Synchronization signal transmission unit, 32 image data reception unit, 33 FIFO, 34 image data processing unit, 35 image data output unit, 51 power control unit, 52 clock signal reception unit, 53 control information communication unit, 54 synchronization signal reception unit, 55 CMOS image sensor, 56 imager, 57 temperature sensor, 58 defect correction ROM, 59 image data transmitter

Claims (10)

In an imaging device consisting of a CCU (camera control unit) and CHU (camera head unit) connected via a cable,
The CCU is
Detection means for detecting a cable length of the cable as a transmission path of image data and an image synchronization signal;
Generating means for generating the image synchronization signal for acquiring the image data from the CHU;
Control means for controlling the transmission timing of the image synchronization signal based on at least the cable length;
In accordance with the transmission timing to be controlled, image synchronization signal transmission means for advancing the phase of the generated image synchronization signal and transmitting it to the CHU via the cable;
Image data receiving means for receiving the image data supplied from the CHU via the cable in response to the transmitted image synchronization signal, and
The CHU is
Image synchronization signal receiving means for receiving the image synchronization signal transmitted from the CCU via the cable;
Image data generation means for performing imaging according to the received image synchronization signal and generating the image data as an imaging result;
An image data transmitting means for transmitting the generated image data to the CCU via the cable. The control means controls transmission timing of the image synchronization signal based on transmission time in the cable length, processing by the image synchronization signal transmission means, processing by the image synchronization signal reception means, and processing by the image data transmission means. The imaging apparatus according to claim 1. The CCU is
Buffering means for buffering the received image data;
The imaging apparatus according to claim 2, wherein the control unit also controls a read timing of the image data buffered in the buffering unit. The image data generating means generates image data of a plurality of channels,
The image data transmitting means transmits the image data of the plurality of channels to the CCU via a plurality of image data transmission paths provided in the cable,
The imaging apparatus according to claim 3, wherein the buffering unit distinguishes and buffers the image data of the plurality of channels. The imaging device according to claim 2, wherein the detection unit detects the cable length based on information recorded in a connector of the cable. In the transmission method of the imaging device consisting of CCU (camera control unit) and CHU (camera head unit) connected via a cable,
By the CCU,
A detection step of detecting a cable length of the cable as a transmission path of image data and an image synchronization signal;
Generating the image synchronization signal for obtaining the image data from the CHU; and
A control step of controlling transmission timing of the image synchronization signal based on at least the cable length;
In accordance with the transmission timing to be controlled, the phase of the generated image synchronization signal is advanced and transmitted to the CHU via the cable; and
In response to the transmitted image synchronization signal, an image data receiving step of receiving the image data supplied from the CHU via the cable;
By the CHU,
An image synchronization signal receiving step for receiving the image synchronization signal transmitted from the CCU via the cable;
An image data generation step of performing imaging according to the received image synchronization signal and generating the image data as an imaging result;
An image data transmitting step of transmitting the generated image data to the CCU via the cable. A program for controlling an imaging device comprising a CCU (camera control unit) and a CHU (camera head unit) connected via a cable,
By the CCU,
A detection step of detecting a cable length of the cable as a transmission path of image data and an image synchronization signal;
Generating the image synchronization signal for obtaining the image data from the CHU; and
A control step of controlling transmission timing of the image synchronization signal based on at least the cable length;
In accordance with the transmission timing to be controlled, the phase of the generated image synchronization signal is advanced and transmitted to the CHU via the cable; and
In response to the transmitted image synchronization signal, an image data receiving step for receiving the image data supplied from the CHU via the cable;
By the CHU,
An image synchronization signal receiving step for receiving the image synchronization signal transmitted from the CCU via the cable;
An image data generation step of performing imaging according to the received image synchronization signal and generating the image data as an imaging result;
An image data transmission step of transmitting the generated image data to the CCU via the cable. In an imaging device consisting of a CCU (camera control unit) and CHU (camera head unit) connected via a cable,
The CCU is
Generating means for generating a clock signal and transmitting it to the CHU via the cable;
Generating means for generating an image synchronization signal for acquiring the image data from the CHU;
Image synchronization signal transmitting means for transmitting the generated image synchronization signal to the CHU via the cable;
Image data receiving means for receiving the image data supplied from the CHU via the cable in response to the transmitted image synchronization signal, and
The CHU is
Clock signal receiving means for receiving the clock signal transmitted from the CCU via the cable and generating a clock signal for CHU;
Image synchronization signal receiving means for receiving the image synchronization signal transmitted from the CCU via the cable;
Image data generating means for performing imaging according to the CHU clock signal and the received image synchronization signal, and generating the image data as an imaging result;
An image data transmitting means for transmitting the generated image data to the CCU via the cable. The image data generating means generates image data of a plurality of channels,
The imaging apparatus according to claim 8, wherein the image data transmission unit transmits the image data of the plurality of channels to the CCU through a plurality of image data transmission paths provided in the cable. In the transmission method of the imaging device consisting of CCU (camera control unit) and CHU (camera head unit) connected via a cable,
By the CCU,
Generating a clock signal and transmitting to the CHU via the cable;
Generating step for generating an image synchronization signal for acquiring the image data from the CHU;
An image synchronization signal transmission step of transmitting the generated image synchronization signal to the CHU via the cable;
In response to the transmitted image synchronization signal, an image data receiving step for receiving the image data supplied from the CHU via the cable;
By the CHU,
A clock signal receiving step for receiving the clock signal transmitted from the CCU via the cable and generating a clock signal for CHU;
An image synchronization signal receiving step for receiving the image synchronization signal transmitted from the CCU via the cable;
An image data generation step of performing imaging according to the CHU clock signal and the received image synchronization signal, and generating the image data as an imaging result;
An image data transmitting step of transmitting the generated image data to the CCU via the cable.

Images