JP5725999B2 - Camera system - Google Patents

Description

  The present invention relates to a camera system that transfers image data from a camera body to a host device by packet communication.

  There are solder printing equipment, component mounting equipment, reflow equipment, board inspection equipment, etc., as board production equipment that produces boards with a large number of electronic components mounted on them. There are many cases. In general, a solder inspection device or an appearance inspection device used as a substrate inspection device includes an inspection camera for imaging a substrate. The inspection camera receives a command from the control computer (higher-order apparatus), images a predetermined area on the substrate, and transfers image data of the captured image to the control computer. The control computer performs predetermined image processing on the received image data, for example, comparison processing with good reference image data, and determines pass / fail. In addition, the component mounting apparatus includes a substrate camera that captures the position of the reference mark and the ID number of the positioned substrate, and a component camera that captures the state of the electronic component that is attracted to the suction nozzle of the component mounting head. It is common. The substrate camera and the component camera also operate in response to a command from the control computer, and transfer image data to the control computer.

  A camera incorporated in this type of substrate production apparatus captures an image based on a command and transfers image data to a control computer, and it can be understood that a camera system is configured by the camera body and the control computer. . In this camera system, image data is transferred in a short time by high-speed wired packet communication in order to increase substrate production efficiency. For example, the data transfer rate of an I / O serial interface (a type of expansion bus) called “PCI-Express 1.0” is 2.5 Gbps per lane (gigabit per second), and the maximum data is available for a camera system using 4 lanes. The transfer rate is 10 Gbps. In this packet communication, the packet size can be changed, and the transfer time and power consumption change according to the size of the packet size. On the other hand, the camera body includes an imaging unit and a data storage unit, and executes output of image data from the imaging unit to the data storage unit and transfer of image data from the data storage unit to the control computer in parallel. The time (reciprocal of the frame rate) can be reduced.

  However, in the parallel operation at the time of imaging described above, the peak power in the camera system tends to increase. An increase in peak power not only simply reduces the margin ratio of the power supply capacity, but also affects reliability such as temperature rise and noise generation, and can contribute to unstable operation and malfunction of the system. For this reason, reduction of the peak power of the camera system is a big problem, and related technical examples are disclosed in Patent Documents 1 and 2.

  The image processing apparatus disclosed in Patent Literature 1 has a problem of reducing the weight, size, and power consumption of the apparatus, and has been read by a reading unit that reads an image signal of a subject from a sensor unit (imaging unit) for each field. Processing means for processing the image signal and drive means for controlling to read out all the fields in the longest readout time are provided. As a result, the image signal is read out from the sensor unit at the same timing regardless of whether or not the resolution is changed. For example, it is not necessary to provide a frame memory, and the processed image signal can be output without troublesome correction. It can be done.

  The imaging apparatus of Patent Literature 2 reduces the power consumption of the detection unit that detects an operation start instruction to the imaging function unit and the wireless function unit that transfers image data before the power consumption of the imaging function unit increases ( And control means for shifting to the low power consumption mode. Thus, the maximum current capacity during the operation of the imaging function unit can be relaxed.

JP 2003-32541 A JP 2008-5212 A

  By the way, since the technique of the image processing apparatus of Patent Document 1 related to the reduction of peak power is directly connected to the sensor unit (imaging unit) and the processing unit, the image data is transferred to a higher-level device separated by packet communication. Not applicable to Further, the function similar to the low power consumption mode of the wireless function unit disclosed in the imaging apparatus of Patent Document 2 is not provided in a communication device that performs wired packet communication, and is also difficult to apply.

  On the other hand, in a camera system incorporated in a board production apparatus, it is not always necessary to transfer image data of the entire captured image by packet communication. For this reason, a part of the captured image required by the control computer (higher level device) is set in the captured image effective area, and only the image data (transfer image data) in the area is transferred, thereby reducing the transfer image size. Transfer time can be reduced. At this time, it is preferable to set the packet size appropriately according to the imaging interval time (reciprocal of the frame rate) and the transfer image size. If the packet size is set too small, the transfer time becomes excessive, the frame rate is automatically corrected to be small, the imaging interval time is extended, and the production efficiency of the board is lowered. Also, if the packet size is set excessively, the power consumption required for transfer becomes excessive and the peak power increases.

  The above problem is the same in camera systems for uses other than board production. Patent Documents 1 and 2 do not disclose a solution for reducing the peak power during imaging with a camera system having a packet communication unit.

  The present invention has been made in view of the above problems of the background art, and appropriately determines the packet size of packet communication in accordance with the setting of the frame rate indicating the frequency of obtaining image data and the effective area of the captured image, and captures the image. It is an object to be solved to provide a camera system that reduces peak power at the time.

  An invention of a camera system according to claim 1 that solves the above problem includes an imaging unit that captures an image of a subject and obtains image data of the captured image, and image data of a captured image effective area that is all or part of the captured image. A data storage unit for storing transfer image data output from the imaging unit, a host device to which the transfer image data is transferred, and the transfer image data from the data storage unit to the host device by packet communication with a variable packet size A camera system including a packet communication unit for transferring, wherein a setting means for setting a frame rate indicating the frequency of obtaining the image data and the captured image effective area, and transfer determined by the size of the captured image effective area Based on the relationship between the image size and the packet size and the transfer time required to transfer the transfer image data, Determining means for determining the packet size so as to increase the transfer time as much as possible within a range not exceeding the imaging interval time indicated by the reciprocal of the frame rate, and a frame rate at which the image data of the captured image is set by the imaging unit And executing means for storing the transfer image data in the data storage unit and transferring the transfer image data in the packet size determined from the data storage unit to the host device by the packet communication unit.

  The invention according to claim 2 is the camera system according to claim 1, wherein the execution unit outputs the transfer image data from the imaging unit to the data storage unit and the transfer by the packet communication unit. The image data transfer is executed in parallel.

  The invention according to claim 3 is the camera system according to claim 1 or 2, wherein the packet communication unit sets a communication device capable of variably setting a maximum payload size representing a maximum packet size in packet communication. The maximum payload size of one of the communication units on the data storage unit side and the host device side is set in advance to an allowable maximum value, and the data storage unit side and host device side respectively. The packet size determined by the determining means is set in the other maximum payload size of the communication device.

  The invention according to claim 4 is the camera system according to any one of claims 1 to 3, and is incorporated in a board production apparatus that produces a board on which electronic components are mounted.

  In the invention of the camera system according to claim 1, the frame rate and the captured image effective area are set, and the transfer time is set as much as possible within the range not exceeding the imaging interval time based on the relationship between the transfer image size and the packet size and the transfer time. The packet size is determined so as to increase, and the transfer image data is transferred with the determined packet size. In general, in packet communication, the transfer time increases as the transfer image size increases, and the transfer time decreases as the packet size increases. Further, as the packet size increases, the power consumption required for transfer increases. Furthermore, when the transfer time becomes excessive and the set frame rate is not maintained, the frame rate is automatically corrected to be small so as to secure the transfer time (in other words, the imaging interval time is greatly corrected). There are many. Therefore, according to the present invention, it is possible to determine the packet size as small as possible within a range that does not affect the frame rate, to reduce the power consumption required for transfer, and to reduce the peak power during imaging.

  In the invention according to claim 2, the peak power is obtained by adding the power consumption required for outputting the transfer image data to the data storage unit and the power consumption required for transferring the transfer image data by the packet communication unit. Here, the power consumption of the former is substantially constant regardless of the captured image effective area (transfer image size), and the required output time becomes longer as the captured image effective area becomes larger. The latter power consumption is reduced if the packet size is reduced even if the captured image effective area is constant, and the transfer time depends on the captured image effective area and the packet size. Therefore, by appropriately determining the packet size, the peak power during imaging can be reduced, and the frame rate is not affected.

  In the invention according to claim 3, the maximum payload size of one of the communication devices on the data storage unit side and the host device side is set in advance to an allowable maximum value, and the determined packet size is set as the other maximum payload size. To do. In general, when the values of both of the maximum payload sizes are different in the packet communication in which the communication device capable of variably setting the maximum payload size is opposed, the packet size is adjusted to the smaller value of the maximum payload size. Therefore, according to this claim, the packet size can be freely changed only by the other of the opposing communication devices, and the setting change operation is simple. Moreover, since the packet communication is immediately reflected when the packet size is set to the other maximum payload size, the setting can be changed even during continuous imaging in which a plurality of image data are continuously obtained. In addition, packet communication is not interrupted by the setting change, and it is not necessary to restart the camera system when the setting is changed.

  In the invention according to claim 4, the camera system is incorporated in a board production apparatus for producing a board on which electronic components are mounted. Since the packet size is determined to be as small as possible without affecting the frame rate, the peak power can be reduced, and the board and electronic components mounted on the board can be imaged at a high frame rate. Thereby, it can contribute to the improvement of the production efficiency of a board | substrate.

It is an external view which shows the apparatus structure of the camera system of embodiment. It is a functional block diagram which shows the function structure of the camera system of embodiment. It is a figure of the timing chart which shows the imaging operation of the camera system of embodiment. It is a figure which illustrates the image of the packet in packet communication typically, (1) has a large packet size, (2) has shown the case where a packet size is small. FIG. 4 is a timing chart illustrating an imaging operation when the packet size is changed to be smaller than in FIG. 3 and other conditions are the same. It is a figure explaining the imaging control flow of the camera system of an embodiment. It is a figure of the oscilloscope waveform which measured the effect of the camera system of an embodiment, (1) shows the case where a packet size is large, and (2) shows the case where a packet size is small.

  A camera system 1 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an external view illustrating a device configuration of a camera system 1 according to the embodiment. The camera system 1 includes a camera body 2, a host device 3, and a communication cable 4. The camera system 1 is incorporated in a component mounting apparatus that mounts electronic components on a substrate. In this case, the camera body 2 is used as a board camera that images the board positioned at the component mounting position. Alternatively, the camera body 2 can be used as a component camera for imaging the state of the electronic component sucked by the suction nozzle of the component mounting head, and two sets of camera bodies 2 can be used as the board camera and the component camera. it can. In either case, the host apparatus 3 is also used as a control computer that controls the operation of the component mounting apparatus.

  The camera system 1 can also be incorporated in a board inspection apparatus that inspects a board on which electronic components are mounted. In this case, the camera body 2 is used as an inspection camera that images the substrate. Furthermore, the camera system 1 can also be used for purposes other than board production. In this case, a general-purpose personal computer or a dedicated image processing board can be used as the host device 3.

  FIG. 2 is a functional block diagram illustrating a functional configuration of the camera system 1 according to the embodiment. As illustrated, the camera body 2 includes an image sensor 21, a volatile memory (DRAM) 22, a flash memory (FROM) 23, a communication device 24, a CPU 29, and the like. On the other hand, the host device 3 includes a communication device 31, a memory 32, a display unit 33, a CPU 39, and the like.

  The image sensor 21 of the camera body 2 corresponds to the imaging unit of the present invention, and for example, a CMOS image sensor can be used. The image sensor 21 captures a subject and obtains image data of the captured image. The volatile memory (DRAM) 22 corresponds to the data storage unit of the present invention, and stores transfer image data output from the image sensor 21. The transfer image data is image data of a captured image effective area that is all or part of the captured image, and the effective area is variably set as will be described later. The flash memory (FROM) 23 stores and holds various information necessary for control. The information held in the flash memory 23 can be changed by rewriting and does not disappear even when the power is turned off. The communication device 24 corresponds to a part of the packet communication unit of the present invention, and the maximum payload size representing the maximum packet size in the packet communication can be variably set. The CPU 29 controls each unit 21 to 24 of the camera body 2.

  The information held by the flash memory 23 is specifically information on a captured image effective area, maximum payload information, frame rate information, relational expressions described later, and information on an imaging sequence. The information of the captured image effective area is information for variably setting all or part of the captured image obtained by capturing the subject. By setting the effective area of the captured image, only necessary portions of the captured image data can be selected as transfer image data, and the transfer image size can be reduced to reduce output and transfer loads. The max payload information stores the setting value of the max payload size. The frame rate information stores frame rate setting values. The frame rate is an index representing how many images are captured and transferred per unit time, and the reciprocal of the frame rate is the imaging interval time Tf.

  On the other hand, the communication device 31 of the host device 3 corresponds to a part of the packet communication unit of the present invention, and the maximum payload size representing the maximum packet size in the packet communication can be variably set. The memory 32 stores the transferred image data, and the display unit 33 displays the transferred image data. The CPU 39 controls each unit 31 to 33 of the higher-level device 3.

  The communication device 24 on the camera body 2 side and the communication device 31 on the host device 3 side are connected by the communication cable 4 and face each other to form a packet communication unit. The packet communication unit transfers the transfer image data by packet communication with a variable packet size. That is, the transfer image data is read from the volatile memory 22 of the camera body 2, transferred via the communication cable 4, and written in the memory 32 of the higher-level device 3. Note that the packet size of the packet communication is adapted to a smaller value of the maximum payload size of the two communication devices 24 and 31 facing each other.

  Next, the imaging operation of the camera system 1 of the embodiment configured as described above will be described. FIG. 3 is a timing chart illustrating an imaging operation of the camera system 1 according to the embodiment. In the figure, the horizontal axis indicates the common time t, and the upper chart indicates the exposure signal E. The middle chart shows the power consumption P1 required to output the transfer image data from the image sensor 21 to the volatile memory 22, and the lower chart shows the transfer image data from the camera body 2 to the host device 3 by the packet communication unit. The power consumption P2 required for the transfer is shown.

  In FIG. 3, when the exposure signal E rises and is turned on at time t1, a shutter (not shown) of the camera body 2 is opened and imaging by the image sensor 21 is started. When the exposure signal E falls at time t2 and is turned off, the shutter is closed and the imaging by the image sensor 21 is completed. At the same time, in response to the fall of the exposure signal E, the output of transfer image data from the image sensor 21 to the volatile memory 22 is started. Further, the transfer of the transfer image data by the packet communication unit is started with a slight delay.

  The output of the transfer image data to the volatile memory 22 ends at time t3, and power consumption P11 is generated during the output time T1 from time t2 to time t3. Thereafter, the transfer of the transfer image data by the packet communication unit ends at time t4, and power consumption P21 is generated during the transfer time T21 from time t2 to time t4. This completes one imaging operation. Next, when the exposure signal E rises again at time t7, the next imaging operation is started and repeated thereafter. The time between time t1 and time t7 is the interval between the current imaging and the next imaging, that is, the imaging interval time Tf. Also, the time during which transfer image data is not transferred, that is, the time between the current transfer end time t4 and the next transfer start time t8 is the transfer free time Tw1. The transfer idle time Tw1 is not necessary for the operation of the camera system 1 and is a wasteful function.

  Here, the power consumption of the camera system 1 is not so large from time t1 to time t2 when the exposure signal E is on. Therefore, the peak power Pp1 of the camera system 1 is generated between the times t2 and t3 when the output and transfer of the transfer image data are performed in parallel. Further, peak power Pp1≈power consumption P11 + power consumption P21. Although it is clear that the peak power Pp1 can be reduced if the transfer image data is output and transferred in series without being parallel, the peak power Pp1 can be reduced, but this is not adopted in this embodiment because the frame rate may be lowered. .

  Next, consider a case where the packet size of packet communication is changed to be small. FIG. 4 is a diagram schematically illustrating an image of a packet in packet communication. (1) shows a case where the packet size SL is large and (2) shows a case where the packet size SS is small. As shown in the figure, the packet image is composed of a header part Sh and a data part Sd. The header portion Sh is a portion of incidental information necessary for packet communication, and has a constant size independent of the packet sizes SL and SS. On the other hand, the data part Sd is a part obtained by dividing the transfer image data, and has a remaining size obtained by subtracting the header part Sh from the packet sizes SL and SS.

  For this reason, when the packet size SS of (2) is small, the overhead, that is, the ratio of the header part Sh to the whole packet increases. In addition, since one piece of transfer image data is divided and transferred, the total number of packets increases, and the total sum of pause times Sx between packets also increases. Therefore, when the packet size SS is small, the transfer time becomes long. Further, when the packet size SS is small, the power consumption P2 decreases due to an increase in the ratio of the pause time Sx.

  FIG. 5 is a timing chart illustrating an imaging operation when the packet size is changed smaller than in FIG. 3 and the other conditions are the same. As shown in the figure, the operation is the same as that in FIG. 3 until imaging by the image sensor 21 is started at time t1, and imaging is finished at time t2 and output and transfer of transfer image data are started. Further, the output image data output to the volatile memory 22 ends at time t3 (output time T1), and the power consumption P11 is generated during this time. The output time T1 required to output the transfer image data is determined by the setting of the captured image effective area, in other words, the transfer image size, and the power consumption P11 is substantially constant regardless of the transfer image size. Further, the output time T1 and the power consumption P11 are not affected by the setting conditions and operation status of the packet communication unit.

  On the other hand, the transfer of the transfer image data by the packet communication unit is completed until time t5 later than that in FIG. That is, the transfer time T22 when the packet size SS of FIG. 5 is small is longer than the transfer time T21 when the packet size SL of FIG. 3 is large. The power consumption P22 generated during the transfer time T22 from time t2 to time t5 is smaller than the power consumption P21 in FIG. Accordingly, the peak power Pp2 (≈power consumption P11 + power consumption P22) when the packet size is changed to be smaller is smaller than the peak power Pp1 in FIG. Also, the transfer available time Tw2 when the packet size is changed to be smaller is smaller than the transfer available time Tw1 in FIG.

  As apparent from the above description, it is preferable to reduce the packet size in order to reduce the peak power. However, if the packet size is set too small, the transfer time becomes too long and there is no transfer free time. Then, since the frame rate is automatically corrected to be small so as to secure the transfer time, the imaging interval time Tf is increased, which causes a problem that the production efficiency of the substrate is lowered. Therefore, it is preferable to determine the packet size appropriately so that the peak power can be reduced within a range that does not affect the frame rate.

  Here, the transfer time of the packet communication unit is determined by using two factors of transfer image size and packet size as parameters. This relationship depends on the performance of the communication devices 24 and 31. In the present embodiment, the relationship between the transfer image size and packet size determined by the size of the captured image effective area and the transfer time required to transfer the transfer image data is obtained in advance, and is stored in the flash memory 23 of the camera body 2 as relational expression information. Store it. Then, the determining unit described later determines the packet size using this relational expression. Instead of the relational expression, a table in a list form may be stored in the flash memory 23 and used.

  Next, the imaging control flow of the camera system 1 will be described. FIG. 6 is a diagram illustrating an imaging control flow of the camera system 1 according to the embodiment. The imaging control flow is mainly performed by the CPU 29 of the camera body 2, and execution is controlled in cooperation with the CPU 39 of the host apparatus 3. In step S1 of FIG. 6, the CPU 29 of the camera body 2 sets the maximum payload size of the communication device 24 to an allowable maximum value when the power is turned on. This maximum value is determined in advance depending on the packet communication standard and the performance of the communication device 24. If the default value of the maximum payload size is the maximum value in the initial setting of the communication device 24, the maximum value is automatically set when the power is turned on, so the setting operation can be omitted.

  In the next step S2, an imaging sequence is commanded from the host device 3 to the camera body 2 via the packet communication unit. The imaging sequence is information including the imaging order of a plurality of captured images, the frame rate, the captured image effective area, and the like. Based on this information, the camera body 2 performs a continuous imaging operation. Information on the imaging sequence is stored and held in the flash memory 23 of the camera body 2. In the next step S3, the imaging operation is started when the condition of the subject is satisfied. In the present embodiment, the camera system 1 is incorporated in a component mounting apparatus, and when the board is loaded and positioned at a predetermined component mounting position, the camera body 2 is driven to a desired position on the upper surface of the board to perform an imaging operation. Is started.

  In the imaging operation, first, in step S4, a frame rate and a captured image effective area are set. Specifically, the CPU 29 of the camera body 2 reads out the frame rate of the captured image to be captured this time and information on the captured image effective area from the flash memory 23 and transmits the information to the image sensor 21. In addition, the same information is transmitted to the host device 3. Step S4 corresponds to setting means of the present invention.

  Next, in step S5, the packet size is determined. The CPU 29 determines the packet size using a relational expression or table that represents the relationship between the transfer image size and the packet size stored in the flash memory 23 and the transfer time. The determined packet size is the smallest value within a range that does not affect the frame rate, in other words, the value that can minimize the transfer idle time and reduce the power consumption to the minimum. Further, the CPU 29 stores and holds the determined packet size in the flash memory 23 and transmits it to the host device 3.

  In step S <b> 6, the CPU 39 of the higher-level device 3 sets the transmitted packet size to the maximum payload size of the communication device 31. As a result, the maximum payload size of the packet communication unit becomes the maximum value in the communication device 24 on the camera body 2 side and the packet size determined by the communication device 31 on the host device 3 side. Therefore, the packet size used for communication is adjusted to the determined packet size on the smaller side, and the packet communication unit is ready for transfer. Steps S5 and S6 correspond to the determining means of the present invention.

  Next, in step S7, the exposure signal E rises, the shutter of the camera body 2 is opened, and the image sensor 21 performs imaging. In step S8 after the exposure is completed, the transfer image data from the image sensor 21 to the volatile memory 22 is output. In parallel with step S8, in step S9, the transfer image data is transferred from the camera body 2 to the host apparatus 3 by the packet communication unit. Steps S7 to S9 correspond to execution means of the present invention.

  Next, in step S10, it is confirmed whether or not all the captured images in the imaging sequence have been captured. If all captured images have not been captured, the process returns to step S7 to move to the next imaging, and if all captured images have been captured, the imaging sequence ends. If at least one of the frame rate and the captured image effective area is changed during the imaging sequence, the process returns to step S4 to reset them.

  Next, effects of the camera system 1 will be described. FIG. 7 is a diagram of an oscilloscope waveform obtained by actually measuring the effect of the camera system 1 of the embodiment. (1) shows a case where the packet size SL is large, and (2) shows a case where the packet size SS is small. The horizontal axis of the waveform indicates time t, the vertical axis indicates the power consumption of the camera system 1, and the reference numerals in the waveform are attached corresponding to FIGS. As illustrated, the transfer time T22 when the packet size SS of (2) is small is longer than the transfer time T21 of (1), and the power consumption P22 required for the transfer of (2) is the power consumption P21 of (1). Smaller than. As a result, the peak power Pp2 in (2) is reduced by several percent from the peak power Pp1 in (1).

  According to the camera system 1 of the embodiment, the power consumption P22 required for transfer can be reduced by determining the packet size as small as possible within a range that does not affect the frame rate. Thereby, peak power Pp2 which added power consumption P11 required for the output to the volatile memory 22 (data storage part) can be reduced. That is, the peak power Pp2 can be reduced without changing the imaging conditions such as the frame rate and the captured image effective area.

  Further, the maximum payload size of the communication device 24 on the camera body 2 side is set in advance to the maximum value, and the determined packet size is set to the maximum payload size of the communication device 31 on the host device 3 side, which is used for packet communication. The packet size can be freely changed, and the setting change operation is simple. Further, since the packet size is immediately reflected when the packet size is set in the communication device 31 on the host device 3 side, the setting can be changed even during continuous imaging in which a plurality of pieces of image data are continuously obtained. In addition, the packet communication is not interrupted by the setting change, and it is not necessary to restart the camera system 1 when the setting is changed.

  The camera system 1 is incorporated in a component mounting apparatus that mounts electronic components on a substrate, and can quickly capture images of the substrate and the electronic components mounted on the substrate at a large frame rate while suppressing peak power. Thereby, it can contribute to the improvement of production efficiency.

  In the waveform example (2) in FIG. 7, since the transfer waiting time Tw2 is large, it can be expected that the packet size SS is further reduced to increase the transfer time T22 and the peak power Pp2 is further reduced. Alternatively, it can be expected that the frame rate is increased to perform a higher-speed imaging operation. Moreover, although the communication devices 24 and 31 of the embodiment employ “PCI-Express 1.0” described in the background art, the packet communication method is not limited to this. In addition, the present invention can be variously applied and modified.

1: Camera system 2: Camera body 21: Image sensor 22: Volatile memory (DRAM) (data storage unit)
23: Flash memory (FROM) 24: Communication device 29: CPU
3: Host device 31: Communication device 32: Memory 33: Display unit 39: CPU
4: Communication cable E: Exposure signal P1, P2, P11, P21, P22: Power consumption Pp1, Pp2: Peak power Tf: Imaging interval time T1: Output time T21, T22: Transfer time Tw1, Tw2: Transfer free time SL, SS: Packet size Sh: Header part Sd: Data part Sx: Pause time

Claims (4)

An imaging unit that captures a subject and obtains image data of the captured image; a data storage unit that stores transfer image data output from the imaging unit as image data of a captured image effective area that is all or part of the captured image; A camera system comprising: a host device to which the transfer image data is transferred; and a packet communication unit that transfers the transfer image data from the data storage unit to the host device by packet communication having a variable packet size,
A setting means for setting a frame rate indicating the frequency of obtaining the image data, and the captured image effective area;
Based on the transfer image size determined by the size of the captured image effective area and the relationship between the packet size and the transfer time required to transfer the transfer image data, a range that does not exceed the imaging interval time indicated by the reciprocal of the frame rate Determining means for determining the packet size so as to increase the transfer time as much as possible;
The imaging unit obtains the image data of the captured image at a set frame rate, stores the transfer image data by the data storage unit, and transfers the transfer image data from the data storage unit by the packet communication unit. Execution means for transferring to the device at the determined packet size;
Camera system equipped with. The camera system according to claim 1,
The execution unit is a camera system that executes the output of the transfer image data from the imaging unit to the data storage unit and the transfer of the transfer image data by the packet communication unit in parallel. The camera system according to claim 1 or 2,
The packet communication unit has a communication device that can variably set the maximum payload size representing the maximum packet size in packet communication on each of the data storage unit side and the host device side,
Preset the maximum payload size of one of the data storage unit side and higher-level device side communication devices to the maximum allowable value,
A camera system that sets the packet size determined by the determining means to the other maximum payload size of the communication device on the data storage unit side and the host device side.   The camera system according to any one of claims 1 to 3, wherein the camera system is incorporated in a board production apparatus for producing a board on which electronic components are mounted.

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