JP2006067446A - Camera system, camera main body, and camera head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera system capable of receiving a correct image signal, and a camera head and a camera main body for each configuring the camera system. <P>SOLUTION: The image signal is to be transmitted to a camera main body 1b side via a fast speed serial I/F 150a after being added a check code at its tail end by an error detection code processing unit 141a provided on the camera head 1a side. The image signal and the check code are to be received by the camera min body 1b via the fast speed serial I/F 150b. A detection whether an error occurs or not in the image signal is made by a communication detecting unit 152b based on the check code, then re-transmission request is to be transmitted to the camera head 1a side via the 3 wired serial I/F if occurrence of the error is detected. The image signal is to be re-transmitted after receiving the re-transmission request by the camera head 1a side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a camera system including a camera head including a photographic optical system and an image sensor, a camera body to which the camera head is detachably attached, and receives an image signal from the camera head and performs signal processing, and the camera The present invention relates to a camera body and a camera head constituting a system.

  When a plug-in unit in which an image sensor and a photographing optical system are integrated is attached to the camera body, information on the plug-in unit is transmitted to the camera body side, and photographing is performed with the photographing optical system included in the plug-in unit. A camera system has been proposed (see Patent Document 1). When a camera system that replaces the photographic optical system, that is, the photographic lens, is realized simply by attaching the plug-in unit to the camera body, the handling of the camera system becomes very simple, and specialized knowledge can be obtained. Even people who do not have it can easily change the photographic lens.

  Similarly, there is a camera system including a camera head including a photographing optical system and an image sensor, and a camera body that is detachably mounted and receives an image signal from the camera head and performs signal processing (for example, Patent Document 2).

  By the way, when the signal is transmitted from the transmitter side to the receiver side through the transmission path regardless of wired / wireless, the signal transmitted from the transmitter side is correctly transmitted through the transmission path and is received by the receiver. In some cases, test data is added to the signal so that it can be checked whether it has been received or not. As such inspection data, checksum and CRC are well known.

  When such inspection data is added to a signal on the transmission side, even if a change occurs in the signal being transmitted due to noise in the transmission path while the signal is being transmitted, the change is received on the receiver side. Is detected as an error. By making a request for retransmission to the transmitter by this detection, it is possible to request retransmission as many times as necessary until a correct signal is received.

  Some of the above camera systems are provided with such an error detection function (see Patent Document 3). However, the camera system of Patent Document 3 uses a control signal exchanged between the camera body and the camera head. The inspection code as described above is applied, not the image signal itself.

  In general, the transmission time of an image signal is longer than that of a control signal, in other words, the length of an image signal representing a subject becomes very long with respect to the time axis, so the probability of error occurrence is considerably larger than that of a control signal. It has become. Thus, if a change occurs in any part of the image signal whose length becomes longer with respect to the time axis, the correct image signal cannot be received on the receiver side.

Some camera systems are deployed to obtain electrical coupling when the camera head is attached to the camera body, assuming that such changes are caused by wraparound from the power supply line. Among many contact points, there is also one in which a contact point for electric power and a contact point for communication are separated from each other (for example, see Patent Document 4).
JP-A-8-172561 JP 2000-175089 A JP-A-11-125860 JP 2004-53876 A

  In view of the above circumstances, an object of the present invention is to provide a camera system that can receive a correct image signal, a camera head that constitutes the camera system, and a camera body.

The camera system of the present invention that achieves the above object includes a camera head having a photographing optical system and an image sensor, a camera body that is detachably mounted, receives an image signal from the camera head, and performs signal processing. In a camera system equipped with
The camera head includes a transmission unit that transmits the image signal to the camera body,
The transmission unit includes an adding means for adding inspection data so that it can be checked later whether or not there is an error in the transmitted image signal when transmitting the image signal to the camera body,
The camera body includes a receiving unit that receives an image signal transmitted from the transmitting unit,
The receiving unit receives the image signal transmitted from the transmitting unit, and also receives the inspection data and detects whether there is an error in the received image signal based on the inspection data. When this is detected, a retransmission request is made to the camera head side.

  In the camera system of the present invention that achieves the above object, both the image signal and the inspection data transmitted from the transmission unit of the camera head are received by the reception unit of the camera body, and the image signal is based on the inspection data. Error is detected. When an error is detected in the image signal in the receiving unit, a retransmission request is transmitted to the camera head, and when the image signal is retransmitted from the camera head in response to the retransmission request, the image is again received on the camera body side. Signal error detection is performed. If no error is detected from the image signal, the image signal is processed assuming that a correct received signal is received. If an error is detected again, a retransmission request is made.

  In this way, a camera system that can receive a correct image signal is realized.

  Here, it is preferable to use a checksum as the inspection data.

  If a checksum that is often used as an error detection code is used as the inspection data, for example, addition and subtraction can be performed using an arithmetic circuit in the CPU, so that an error detection function can be provided in the camera system relatively easily. Can be given.

The camera body constituting such a camera system is
A camera body that is detachably mounted with a camera head including an imaging optical system and an image sensor, receives an image signal from the camera head, and performs signal processing,
The camera head includes a transmission unit that transmits the image signal to the camera body,
The transmission unit is provided with an adding means for adding inspection data so that it can be checked later whether there is an error in the transmitted image signal when transmitting the image signal to the camera body,
The camera body includes a receiving unit that receives the image signal transmitted from the transmitting unit,
The receiving unit receives the image signal transmitted from the transmitting unit of the camera head, and also receives the inspection data and detects whether the received image signal has an error based on the inspection data. When it is detected that there is an error, it is preferable to make a request for retransmission to the camera head side, and it is preferable to use a checksum as the check data as described above.

Furthermore, the camera head constituting the camera system is
A camera head comprising a photographic optical system and an image sensor, detachably mounted on a camera body that receives an image signal and performs signal processing, and transmits the image signal to the camera body,
The camera head includes a transmission unit that transmits the image signal to the camera body,
The transmission unit includes an adding unit that adds inspection data so that it can be checked later whether or not there is an error in the transmitted image signal when transmitting the image signal to the camera body. It is preferable that the checksum is used as the inspection data as described above.

  As described above, a camera system that can receive a correct image signal, a camera head that constitutes the camera system, and a camera body are realized.

  Embodiments of the present invention will be described below.

  FIG. 1 is a diagram showing a camera system according to an embodiment of the present invention.

  As shown in FIG. 1, the camera system 1 of this embodiment includes a camera head 1a and a camera body 1b. FIG. 1 shows a camera head 1a having a photographing optical system and an image sensor, and a camera body 1b to which the camera head 1a is detachably attached and receives an image signal from the camera head 1a and performs signal processing. Yes.

  The appearance of the camera head 1a is the same as that of a conventional interchangeable lens.

  In the center of the camera body 1b, a head mount 10b having a large number of mount contacts is provided. A similar mount portion is also formed on the camera head 1a side, and when the camera head 1a is mounted on the camera body 1b along the alternate long and short dash line in the drawing so that the positions of both mount contacts match, The mount contacts are connected to each other, and the camera head 1a and the camera body 1b are electrically connected.

  Each of the mount contacts is assigned for communication and power supply, and communication from the camera body 1b to the camera head 1a is performed, or from the camera head 1a to the camera body 1b. In addition, power is supplied from the camera body 1b side to the camera head 1a side.

  An AWB sensor 11b is provided above the head mount 10b, and a light source type at the time of photographing is detected by the AWB sensor 11b. The light source type is, for example, whether it is sunlight or a fluorescent lamp. This light source type is detected by an AWB sensor, and an appropriate color temperature is set in a digital signal processing unit to be described later. White balance is adjusted. A flash light emission window 12b is provided beside the AWB sensor 11b, and a flash light emission device that emits flash light through the flash light emission window 12b is provided in the camera body 1b. Further, a release button 13b and a mode dial 14b are provided on the upper surface of the camera body 1b. The mode dial 14b selects a shooting mode and a playback mode. In the shooting mode, a still image shooting mode or a moving image shooting mode is further selected.

  Here, the internal configuration of the camera system shown in FIG. 1 will be described with reference to FIG.

  FIG. 2 is a block diagram showing an internal configuration of the camera system when the camera head 1a is mounted on the camera body 1b.

  The configuration of the camera head 1a is shown on the upper side of FIG. 2, and the configuration of the camera body 1b is shown on the lower side of FIG.

  First, the configuration around the power supply of this camera system will be briefly described.

  The DC / DC converter 101a on the camera head 1a side and the DC / DC converter 141b on the main body side operate by receiving the power supply of the battery of the camera main body. The power control unit 100a on the camera head side, the camera main body side Are respectively controlled by the power supply control unit 140b.

  When a power-on instruction is issued by a user operation by operating the mode dial 14b when the camera head 1a is attached to the camera body 1b, the DC / DC converter is supplied from the power control unit 140b on the camera body side. An instruction is issued to 141b, and power from the battery is supplied to each part in the camera body 1b. When the power from the battery is supplied to each part of the camera body in this way, the power control unit 140b on the camera body 1b side, the latch unit 160b, and the I / O unit 161b are also passed to the power control unit 100a on the camera head 1a side. The power supply instruction is transmitted, and the battery power is supplied to each part on the camera head 1a side via the DC / DC converter 101a.

  When the camera head 1a is attached to the camera body 1b, a low signal (ground level) is supplied from the camera head 1a side to the power control unit 140b on the camera body 1b side. When an instruction to turn on the power is issued by the mode dial 14b, the latch unit 160b is switched from low to high or from high to low by the power control unit 140b on the camera body 1b, and is latched as it is. A latch signal is supplied to the / O unit 161b. Further, the latch signal is transmitted as a power-on instruction from the I / O unit 161b to the power supply control unit 140b on the camera head 1b side. That is, when the mode dial is operated and the power switch 14b is turned on, power is supplied to each part from the DC / DC converter 140b on the camera body 1b side and the DC / DC converter 101a on the camera head 1a side, and this entire camera system. Is designed to start up as a camera system.

  Next, the flow of an image signal transmitted from the camera head 1a to the camera body 1b when the power is turned on and the camera system operates to take a picture will be described.

  First, the configuration on the camera head 1a side will be described.

  As shown in FIG. 2, a camera head 1a constituting the camera system 1 is provided with a photographing optical system 11a and an image pickup device (hereinafter referred to as a CCD because a CCD solid-state image pickup device is used) 12a. . In the photographing optical system 11a, a photographing lens, a diaphragm and the like are provided. The subject is imaged on the CCD 12a by the photographing lens in the photographing optical system 11a, and image data is generated by the CCD 12a. The image data generated by the CCD 12a is output to the analog signal processing unit 13a and subjected to noise reduction processing by the analog signal processing unit 13a. Then, the analog signal image signal is converted into a digital signal by the A / D unit 14a at the subsequent stage. The image signal is converted into the image signal and supplied to the error detection code processing unit 141a. The error detection code processing unit 141a supplies an image signal to which a check code, here a sum check code is added, to the high-speed serial I / F 150a, and passes through the high-speed serial I / F 150a and the high-speed serial I / F 150a of the camera body. An image signal converted into a digital signal is transmitted to the camera 1b main body side. Here, image signals output one after another from the CCD 12a side are supplied to the error detection code processing unit 141a, and the error detection code processing unit 141a divides each block into a plurality of blocks. Then, the high-speed serial I / F 150a is used for transmission to the camera body 1b. In this way, if a series of image signals is divided into small blocks by the error detection code processing unit 141a to create a packet, the communication detection unit 152b on the camera body side detects errors for each small block. Can be performed. Then, in order to receive a correct image signal on the camera body 1b side, it is only necessary to send a retransmission request for the image signal for each small block to the camera head 1a side, and an error is detected from the camera head 1a side in response to this retransmission request. It is only necessary to transmit the image signal of only the small block portion.

  In the camera head of this embodiment, an image memory is provided in the high-speed serial I / F so that an image signal for each block can be transmitted to the camera body in response to a retransmission request. When there is a retransmission request from the above, the image signal of the block for which the retransmission request has been made can be transmitted again. The error detection code processing unit 141a and the high-speed serial I / F 150a correspond to the transmission unit referred to in the present invention.

  Among the image signals transmitted to the camera body side, an object captured by the photographing lens in the photographing optical system when any photographing mode is selected by the mode dial 14b is displayed on the LCD panel (not shown). The still image obtained by operating the release button 13b when the image signal for the through image (hereinafter referred to as the through image signal) to be displayed on the screen or the still image shooting mode in the shooting mode is selected. An image signal representing an image (hereinafter referred to as a still image signal) or an image signal representing a moving image obtained by operating the release button 13b when the moving image mode in the shooting mode is selected (hereinafter referred to as a moving image signal). There are three image signals.

  Note that the image signal converted into a digital signal by the A / D unit 14a is also supplied to an integration circuit 16a provided at a subsequent stage of the A / D unit 14a. The integration circuit 16a performs an AF function (hereinafter referred to as AF) and an AE function (hereinafter referred to as AE). The integration circuit 16a uses the integration circuit 16a to measure the field luminance and activate the AF function. The subject distance is measured. The subject distance and the field luminance measured by the integrating circuit 16a are supplied to the aperture / focus / zoom control unit 17a via the data bus 192a, and the aperture / focus / zoom control unit 17a uses the aperture in the photographing optical system. Or the position of the focus lens in the photographing optical system is adjusted. In this way, each time the lens in the photographic optical system provided in the camera head 1a is directed to a different subject, AF and AE are activated and the focus and brightness are adjusted immediately to represent the subject in focus. Data is generated by the CCD 12a and output from the CCD 12a.

  The above is the configuration on the camera head 1a side.

  Next, the configuration on the camera body side will be described.

  As described above, when the image signal generated on the camera head side is supplied to the camera body 1b via the high-speed serial I / Fs 150a and 150b, it is first transmitted from the camera head 1a side by the communication detection unit 152b of the camera body 1b. It is checked whether there is an error in the incoming image signal. Here, based on the inspection code added to the tail of the image signal by the error detection code processing unit 141a, it is checked whether there is an error in the received image signal before receiving the inspection code. If an error is detected by the communication detection unit 152b, a retransmission request is transmitted to the camera head side through the 3-wire serial I / F 151b under the control of the main body CPU 100b. In response to this retransmission request, the image signal stored in the image memory in the high-speed serial I / F 150a is read out and retransmitted to the camera body 1b. When the image signal is retransmitted from the camera head 1a to the camera body 1b in this manner, the communication detection unit 152b detects the error again. If there is no error, the image signal is supplied to the digital signal processing unit 103b. . The main body side CPU 100b, the high-speed serial I / F 150b, the communication detection unit 152b, and the three-wire serial I / F 151b correspond to the receiving unit according to the present invention.

  In the present embodiment, as described above, since any one of the three types of image signals of the through image signal, the still image signal, and the moving image signal is transmitted from the camera head 1a, is there any error in those image signals? Whether or not the communication detection unit 152b is all checked. If the communication detection unit 152b determines that there is no error in the image signal, for example, if the image signal is a through image signal, the through image signal is processed by the digital signal processing unit 103b and the processing is performed. The received image signal is supplied to the LCD control unit 105b and the LCD 1050b via the frame memory 104b, and a through image based on the through image signal is displayed on the LCD display screen. Since information from the OSD (On Screen Display) 1051b side is also supplied to the LCD control unit 105b, a selection menu and the like are displayed together with the through image.

  As described above, since the packet is generated for each block, if an error is detected by the communication detection unit, a request for retransmission of the image signal of the portion where the error is detected is sent to the camera head through the 3-wire serial 151b. Sent to 1a. Upon receiving this retransmission request, the camera head 1a side transmits the image signal of the portion where the error is detected to the camera body 1b side, and causes the communication detection unit on the receiver side to perform error detection again. Here, the communication detector 152b checks again whether or not there is an error in the image signal. If it is determined that there is no error, a through image is displayed based on the image signal without the error. In the present embodiment, instead of the entire image signal, the image signal is blocked into a packet so that only the image signal in the packet can be retransmitted, and the packet is instantaneously transmitted to the camera body. By doing so, the processing time is shortened as much as possible.

  When the release button 13b is pressed while viewing the through image, when the still image signal generated by the CCD 12a is transmitted to the camera body via the high-speed I / F, the communication detection unit 152b determines each block. If an error is detected in all the blocks and no error is detected in all blocks, the signal processing is performed by the digital signal processing unit 103b in the same manner as the through image signal, and the signal is further loaded into the memory card slot 107b via the card I / F 106b. JPEG-compressed still image signal is recorded on the memory card 108b.

  When the digital signal processing unit 103b further processes the moving image signal, an MPEG-compressed image signal, for example, is recorded on the memory card 108b loaded in the memory card slot 107b via the card I / F 106b. .

  The image signal to which the inspection code is added is transmitted to the camera body side by the high-speed serial I / F, and the transmitted image signal is received by the high-speed serial I / F. Whether or not there is an error is checked by the communication detection unit 152b.

  The above is the flow of the image signal.

  Finally, the configuration of other components provided in the camera body 1b will be described.

  The camera body 1b includes a portion for processing image signals, a timer 110b for generating data for displaying time and date information on the LCD screen via the OSD 1051b, a calendar clock 111b, and other external devices. A USB I / F 131b for connection and a USB connector 130b, a switch / LED 132b for giving an operation instruction to the camera system and performing a simple display are also provided. This switch operation instruction or the like is supplied to the main body CPU 100b via the I / O 133b, and the main body CPU 100b performs processing according to the operation instruction. However, the release button 13b is directly connected to the interrupt terminals of both the main body CPU 100b and the head CPU 19a. When the release button 13b is pressed, both the CPUs 19a and 100b are interrupted and a still image processing program or a moving image program is executed. It is supposed to be activated.

  Here, the configuration of one packet among a plurality of packets generated by being divided into small blocks by the camera head will be described with reference to FIG.

  FIG. 3 is a diagram illustrating the configuration within one packet 2.

  A packet id 21 is added to the head of the packet 2 as an identification number so that it can be identified which one of the plurality of packets. An image signal 22 is arranged following the packet id, and an inspection code 23 here is added with a checksum at the end.

  Here, assuming that the image signal 22 is composed of a code string expressed as, for example, 1EFF in hexadecimal, the error detection code processing unit 141a adds them to 1 + E + F + F +. Furthermore, a value (C) obtained by subtracting the total from a predetermined value, for example, 100 is added as the check code for the sum check at the end and transmitted to the camera body via the high-speed I / F. I am doing so. Upon receiving this transmission, the communication detector 152b on the camera body side determines whether or not 1 + E + F + F +... + C = 100 and if it does not reach 100, a retransmission request is made through the 3-wire serial I / F 151b as an error has occurred. Transmission is made to the camera head 1a side.

  FIG. 4 is a flowchart illustrating a processing procedure that the main body CPU 100b on the camera main body 1b side causes the high-speed serial I / F 151b and the communication detection unit 152b to perform.

  In step S401, the high-speed communication I / F 151b receives the image signal and the inspection code (sum check) transmitted from the camera head 1a. In the next step S402, the communication detection unit 152b is caused to detect an error in the image signal based on the inspection code. If the communication detection unit detects that there is no error, it determines that there is no error in the image signal and proceeds to the OK side to end the processing of this flow. If it determines that there is an error in step S402, it proceeds to the NG side and proceeds to the packet. A retransmission request is transmitted to the camera head 1a by controlling the 3-wire serial I / F 151b.

  When the image signal is retransmitted from the camera head 1a side, the high-speed serial I / F 151b receives the image signal, and when the communication detection unit determines that there is no error in the received image signal, the processing of this flow ends. If it is determined here that there is an error, the processes in steps S403 and S404 are repeated.

  As described above, the camera system that can receive a correct image signal, the camera head that constitutes the camera system, and the camera body are realized.

  In the present invention, an error detection code is used because it is easy to configure and error detection can be performed reliably. However, if there is an error correction code that can obtain a corresponding correction capability, error correction is used instead of the error detection code. A sign may be used. Then, by receiving the image signal transmitted with the error correction code at the receiving side, it is possible to perform error correction of the image signal at the receiver side without making a retransmission request to the transmitting side and causing retransmission. .

It is a figure which shows the camera system which is one Embodiment of this invention. It is a block diagram which shows the internal structure of a camera system when the camera head 1a is in the state with which the camera main body 1b was mounted | worn. FIG. 3 is a diagram illustrating a configuration within one packet 2. It is the flowchart which showed the process sequence which main body CPU100b by the side of the camera main body 1b performs with the high-speed serial I / F151b and the communication detection part 152b.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera system 1a Camera head 100a Power supply control part 101a DC / DC converter 11a Image pick-up optical system 12a CCD
13a Analog signal processing unit 14a A / D unit 141a Error detection code processing unit 150a High-speed serial driver 151a 3-wire serial driver 16a Integration circuit 17a Aperture / focus / zoom control unit 18a TG
19a Head CPU
190a System memory (ROM / RAM)
191a Non-volatile memory 192a Data bus 1b Camera body 10b Head mount 100b Body CPU
101b System memory 102b Non-volatile memory 103b Digital signal processing unit 104b Frame memory 105b LCD control unit 1050b LCD
106b Card I / F
107b Memory card slot 108b Memory card 150b High-speed serial driver 151b 3-wire serial driver 152b Communication detector

Claims (6)

In a camera system comprising: a camera head provided with an imaging optical system and an image sensor; and a camera body that is detachably mounted and receives an image signal from the camera head and performs signal processing;
The camera head includes a transmission unit that transmits the image signal to the camera body,
The transmission unit includes an adding unit for adding inspection data so that it can be checked later whether or not there is an error in the transmitted image signal when transmitting the image signal to the camera body,
The camera body includes a receiving unit that receives an image signal transmitted from the transmitting unit,
The receiving unit receives the image signal transmitted from the transmitting unit, and also receives the inspection data, detects whether there is an error in the received image signal based on the inspection data, and has an error. And a camera system which makes a retransmission request to the camera head side when it is detected.   The camera system according to claim 1, wherein a checksum is used as the inspection data. In a camera body that is detachably mounted with a camera head including a photographing optical system and an image sensor, receives an image signal from the camera head, and performs signal processing.
The camera head includes a transmission unit that transmits the image signal to the camera body,
The transmission unit includes an adding unit that adds inspection data so that the transmitted image signal can be checked later for an error in transmitting the image signal to the camera body,
The camera body includes a receiving unit that receives an image signal transmitted from the transmitting unit,
The receiving unit receives the image signal transmitted from the transmitting unit, and also receives the inspection data, detects whether there is an error in the received image signal based on the inspection data, and has an error. And a camera body which makes a retransmission request to the camera head side when it is detected.   4. The camera body according to claim 3, wherein a checksum is used as the inspection data. In a camera head that includes a photographic optical system and an image sensor, is detachably attached to a camera body that receives an image signal and performs signal processing, and transmits the image signal to the camera body.
The camera head includes a transmission unit that transmits the image signal to the camera body,
The transmission unit includes an adding means for adding inspection data so that it can be checked later whether or not there is an error in the transmitted image signal when transmitting the image signal to the camera body. A camera head characterized by   6. The camera head according to claim 5, wherein a checksum is used as the inspection data.

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