JP2006093968A - Image data transmission system, image data transmitter, image data receiver, image data transmission method and image data receiving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image data transmission system capable of accurately transmitting image data, an image data transmitter, and an image data receiver; and an image data transmitting method capable of exactly transmitting the image data, an image data transmitting method, a data receiver and image data receiving method. <P>SOLUTION: The image data transmission system is composed of a sending side apparatus for transmitting image data showing images and a receiving side apparatus for receiving the image data sent by the sending side apparatus. The sending side apparatus comprises a clock generator 132 for generating the reference clock of a specified frequency and a sender 133 for sending the image data synchronously with the reference clock of the image data. The receiving side apparatus comprises a send indicator 233 for periodically sending send indication signals to the transmitter of the send side apparatus for indicating the sending timing of image data upon giving a request to send the image data to the sending side apparatus. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image data transmission system for exchanging image data representing an image, an image data transmitting apparatus for transmitting image data, an image data receiving apparatus for receiving image data, an image data transmitting method for exchanging image data, and an image The present invention relates to an image data transmission method for transmitting data and an image data reception method for receiving image data.

Conventionally, various transmission methods for transmitting electronic data between two different devices have been proposed (see, for example, Patent Documents 1 to 11). Here, in many transmission systems, electronic data is sent in synchronization with some reference clock. For example, consider an image forming system that includes an image forming apparatus such as a copier or a printer, and a transmission source that transmits image data to the image forming apparatus. Conventionally, in many of such image forming systems, first, an image data transmission request is sent from an image forming apparatus to an image data transmission source, and a reference clock having a frequency that can be processed by the image forming apparatus is transmitted. The transmission source performs processing such as transmitting image data in synchronization with the reference clock.
JP-A-7-321841 (pages 10-49, FIG. 14) JP-A-8-18535 (page 4-6, FIG. 3) JP-A-9-284745 (page 5-16, FIG. 1) JP-A-9-284746 (page 5-16, FIG. 1) JP-A-9-284747 (page 4-19, FIG. 1) Japanese Patent Laid-Open No. 9-284748 (page 4-19, FIG. 1) JP-A-10-108161 (page 4-14, FIG. 1) JP 2000-209457 A (page 3-10, FIG. 13) JP 2001-339554 A (page 5-10, FIG. 4) JP 2001-339555 A (Page 5-10, FIG. 4) JP 2002-288073 A (page 3-7, FIG. 7)

  However, in the above-described image forming system, the reference clock received by the image data transmission source from the image forming apparatus that is the image data transmission destination is the so-called jitter or duty collapse caused by disturbances during transmission. There is a high possibility that the waveform quality will be degraded, and the reliability of image data transmission may be significantly reduced.

  In the above description, the problem of a decrease in data transmission reliability in an image forming system including an image forming apparatus and a transmission source that transmits image data to the image forming apparatus has been described. However, this problem is generally caused by an image data transmission system that exchanges image data, including an image reading system including a scanner that reads a document and obtains image data and an apparatus that can send image data from the scanner. Image data transmitting apparatus in general for transmitting data, image data receiving apparatus in general for receiving image data, image data transmitting method in general for exchanging image data, image data transmitting method in general for transmitting image data, and image data This is a problem that occurs in the same manner for the general image data receiving method when receiving the image data.

  In view of the above circumstances, the present invention provides an image data transmission system, an image data transmission device, an image data reception device, an image data transmission method capable of accurately transmitting image data, and image data. It is an object of the present invention to provide a transmission method and an image data reception method.

An image data transmission system of the present invention that achieves the above object includes an image data receiving device that receives image data representing an image, and the image data is sent to the image data in response to a transmission request for the image data from the image data receiving device. In an image data transmission system comprising an image data transmission device for transmitting to a data reception device,
The image data transmitting device is
A clock generator for generating a reference clock having a predetermined frequency;
And a transmission unit that transmits the image data in synchronization with the reference clock.

  According to the image data transmission system of the present invention, the image data is transmitted using the reference clock generated internally in the image data transmission device. For this reason, it is suppressed that the reference clock used for transmission is subjected to disturbance and the like, and image data can be transmitted using the reference clock with high waveform quality. That is, according to the image data transmission system of the present invention, image data can be transmitted accurately.

  In addition, when the image data is transmitted, the reference clock is also transmitted to the image data receiving apparatus. According to the image data transmission system of the present invention, the transmission path for the reference clock is the image data transmitting apparatus. Only in one direction from the camera to the image data receiving apparatus. As a result, the transmission path is simplified. For example, the cost for configuring the transmission path with a cable, a connector, or the like is suppressed. Further, it is generally known that a cable through which a clock signal passes becomes a noise source of electromagnetic noise. However, according to the image data transmission system of the present invention, the transmission path related to the reference clock is simplified. Noise is reduced.

  Further, the image data may be handled in a state of being synchronized with a clock having a frequency different from the reference clock until it is transmitted. As a method of transmitting such image data in synchronization with the reference clock, for example, an image A method is known in which data is temporarily stored in a memory and then image data is transmitted from the memory in synchronization with a reference clock. This method requires memory design in accordance with both the frequency of the clock with which the image data before transmission is synchronized and the frequency of the reference clock. Here, if the reference clock is sent from the image data receiving device as in the prior art, the frequency of the reference clock may be different depending on the type of the image data receiving device. Therefore, it is necessary to design a memory with a margin, assuming a certain frequency range as the frequency of the reference clock. However, according to the image data transmission system of the present invention, since the frequency of the reference clock is uniquely determined, the above memory design and peripheral clock synchronization design are simplified. Therefore, the degree of design freedom of the image data transmitting apparatus is increased and the cost is reduced by the simplification of the memory design and the peripheral clock synchronization design.

  Furthermore, when designing an image data transmission system in which an existing device such as a fax machine is handled as the image data transmission device, according to the image data transmission system of the present invention, the existing clock generator in the device is The cost can be reduced by using the design convenience such as the clock generation unit.

Here, in the image data transmission system of the present invention, “This image data transmission system transmits and receives the image data according to a predetermined communication standard,
The image data receiving apparatus includes a processing unit that performs data processing on the received image data at a predetermined processing speed,
The clock generation unit generates a reference clock having a frequency corresponding to both the communication standard and the processing speed of the processing unit, or
“The image data transmitting device and the image data receiving device are connected by a predetermined communication cable,
The image data receiving apparatus includes a processing unit that performs data processing on the received image data at a predetermined processing speed,
A form in which the clock generation unit generates a reference clock having a frequency corresponding to both the length of the communication cable and the processing speed of the processing unit is a preferable mode.

  According to the image data transmission system of these preferred embodiments, the image data transmission device has a frequency suitable for processing in the processing unit of the image data reception device according to the communication standard or the length of the communication cable. Image data synchronized with the reference clock can be transmitted.

In the image data transmission system of the present invention, “when the image data receiving device makes a transmission request for the image data to the image data transmitting device, a transmission instruction signal for instructing the transmission timing of the image data. Is provided with a transmission instruction unit that periodically transmits to the transmission unit of the image data transmission device,
The form that the transmission unit transmits image data every time the transmission instruction signal is received is a preferable form.
The image data transmission system of this preferred form is: “This image data transmission system transmits and receives pixel value data representing pixel values of a plurality of two-dimensionally arranged pixels each having a pixel value as the image data. Is to perform
Each time the transmission unit of the image data transmission apparatus receives the transmission instruction signal, the transmission unit transmits pixel value data for one row in which pixel values of pixels for one row are combined. May be.

  In an image forming apparatus such as a copying machine or a printer, a process of forming an image composed of a plurality of pixels arranged two-dimensionally for each predetermined pixel group such as one row or two rows is executed. In such an apparatus, it is desirable that pixel value data in which the pixel values of the pixels constituting the predetermined unit pixel group are collected is sent. According to the preferred embodiment of the image data transmission system, it is possible to easily realize such desirable image data transmission in which the image forming apparatus is the image data receiving apparatus.

  Further, in the image data transmission system according to the preferred embodiment, “the image data receiving device includes a transmission interruption unit that temporarily interrupts transmission of the transmission instruction signal in the transmission instruction unit”. The form is a more preferred form.

  According to this more preferable form of the image data transmission system, for example, when the image data receiving apparatus becomes very busy, and the image data transmitted from the transmission unit cannot be temporarily processed, etc. Efficiency such as interrupting transmission of the transmission instruction signal by the transmission interrupting unit, temporarily stopping transmission of image data from the image data transmitting device, and causing the image data receiving device to intensively perform its busy processing. Operations can be performed.

In the image data transmission system according to the preferred embodiment, “the image data receiving device instructs the amount of image data transmitted by the transmitting unit every time the transmitting unit receives the transmission instruction signal. An image data amount instruction unit for transmitting a signal to the transmission unit of the image data transmission device,
The transmission unit of the image data transmission device transmits data having a data amount that may further include a quantitative error in the data amount indicated by the image data amount instruction signal.
The image data receiving device, when image data having a data amount exceeding the data amount indicated by the image data amount instruction signal is transmitted from the transmission unit at one transmission timing, A form of “including an excess image data discarding unit that discards excess image data” is also a more preferable form.

  For example, depending on the image data transmission method such as compressing and transmitting image data from the image data transmitting device to the image data receiving device, data including a quantitative error in the data amount indicated by the image data amount instruction signal An amount of image data may be transmitted. According to the image data transmission system of the further preferred embodiment, the excess image data among the image data including such errors is discarded, so that the image data receiving apparatus can process the image data more accurately. Can do.

  In the image data transmission system according to the further preferred embodiment, “the image data receiving device receives image data having a data amount smaller than the data amount instructed by the image data amount instruction signal from the image data transmitting device. When the image data is transmitted at one transmission timing, the data amount of the received image data is added to the data amount of the image data by adding a data amount corresponding to the difference between the two to the image data amount. A form that includes an image data adding unit that matches the data amount indicated by the instruction signal is a more preferable form.

  Depending on the error that occurs when the image data is transmitted in the image data transmission device, the data amount of the image data is the minimum when the image formation is performed in the image forming device, for example, as indicated by the image data amount instruction signal. There are cases where the amount of data such as a processing unit is not satisfied. According to the image data transmission system of the above-mentioned more preferable form, even in such a case, the data amount of the received image data is determined by the method such as adding data representing a blank to the received image data. The amount of data can be matched.

In the image data transmission system according to the present invention, “the image data transmitting device indicates which image data among the image data transmitted by the transmitting unit at one transmission timing is valid image data. An effective image data instruction unit for transmitting an image data instruction signal to the image data receiving device;
Image data other than the image data indicated by the effective image data instruction signal among the image data transmitted from the transmission unit at one transmission timing by the image data receiving device. Is also a preferable mode. "

  According to the image data transmission system of this preferred form, for example, data other than effective image data such as noise included in the effective image data transmitted by the image data transmitting apparatus and effective image data are clearly distinguished. In the image data transmitting apparatus, valid image data can be accurately received.

The image data transmitting apparatus of the present invention that achieves the above object transmits the image data to the image data receiving apparatus in response to a transmission request for the image data from the image data receiving apparatus that receives the image data representing the image. In the image data transmission device to
A clock generator for generating a reference clock having a predetermined frequency;
And a transmission unit that transmits the image data in synchronization with the reference clock.

An image data receiving apparatus of the present invention that achieves the above object is an image data receiving apparatus that receives image data representing an image.
A transmission request unit that performs only a transmission request among a transmission request of the image data and a transmission of a reference clock synchronized with the image data to an image data transmission device that transmits the image data;
The image data transmitting apparatus includes a receiving unit that receives image data transmitted in synchronization with a reference clock internally generated in the image data transmitting apparatus in response to the transmission request.

  According to the image data transmitting apparatus or the image data receiving apparatus of the present invention, it is possible to transmit or receive image data using a reference clock having a high waveform quality generated internally in the image data transmitting apparatus. That is, according to the image data transmitting device of the present invention or the image data receiving device of the present invention, image data can be transmitted accurately.

  It should be noted that the image data transmitting apparatus of the present invention or the image data receiving apparatus of the present invention is shown here only for its basic form, but this is merely for avoiding duplication, and the image data transmitting apparatus of the present invention. Alternatively, the image data receiving apparatus of the present invention includes not only the above basic form but also various forms corresponding to the above-described forms of the image data transmission system of the present invention.

An image data transmission method that achieves the above-described object includes an image data receiving device that receives image data representing an image, and the image data in response to a transmission request for the image data from the image data receiving device. In an image data transmission method with an image data transmission device to be transmitted to a reception device,
A clock generation process for generating a reference clock having a predetermined frequency in the image data transmitting device;
A transmission process of transmitting the image data in synchronization with the reference clock;
It has a reception process of receiving image data transmitted in synchronization with the reference clock in the transmission process.

An image data transmission method that achieves the above object is a method of transmitting image data to the image data receiving apparatus in response to a request for transmitting the image data from an image data receiving apparatus that receives image data representing an image. In the transmission method,
A clock generation process for generating a reference clock of a predetermined frequency;
A transmission step of transmitting the image data in synchronization with the reference clock.

An image data receiving method for achieving the above object is an image data receiving method for receiving image data representing an image.
A transmission request process for performing only a transmission request among a transmission request for the image data and a transmission of a reference clock synchronized with the image data to the image data transmission apparatus that transmits the image data;
The image data transmitting apparatus has a receiving process of receiving image data transmitted in synchronization with a reference clock internally generated in the image data transmitting apparatus in response to the transmission request.

  According to the image data transmission method of the present invention, the image data transmission method of the present invention, or the image data reception method of the present invention, image data using a reference clock having a high waveform quality generated internally in the image data transmission device. Can be transmitted or received. That is, according to the image data transmission method of the present invention, the image data transmission method of the present invention, or the image data reception method of the present invention, image data can be transmitted accurately.

  The image data transmission method according to the present invention, the image data transmission method according to the present invention, or the image data reception method according to the present invention is shown only in its basic form here, but this is merely to avoid duplication. Thus, the image data transmitting apparatus or the image data receiving apparatus of the present invention includes not only the above basic form but also various forms corresponding to the above-described forms of the image data transmission system of the present invention.

  As described above, according to the present invention, the image data transmission system, the image data transmitting device, the image data receiving device, the image data transmitting method capable of accurately transmitting the image data, and the image can be transmitted. A data transmission method and an image data reception method can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, an embodiment of the image data transmission method of the present invention will be described.

  FIG. 1 is a flowchart showing an embodiment of an image data transmission method of the present invention.

  The image data transmission process shown in this flowchart is performed between an image data transmitting device and an image data receiving device, which will be described later, an image data amount instruction process (step S101), a cable length acquisition process (step S102), It consists of a clock generation process (step S103), a transmission interruption process (step S104), a transmission instruction process (step S105), a transmission process (step S106), a valid data instruction process (step S107), and a reception processing process (step S108). .

  Here, the cable length acquisition process (step S102), the clock generation process (step S103), the transmission process (step S106), and the valid data instruction process (step S107) are processes executed by the image data transmission device. An embodiment of the image data transmission method of the present invention is configured. Further, the clock generation process (step S103) and the transmission process (step S106) correspond to examples of the clock generation process and the transmission process according to the present invention. The image data amount instruction process (step S101), the transmission interruption process (step S104), the transmission instruction process (step S105), and the reception process (step S108) are processes executed by the image data receiving apparatus. An embodiment of the image data receiving method of the present invention is configured. Further, the transmission instruction process (step S105) and the reception processing process (step S108) correspond to examples of the transmission request process and the reception process according to the present invention, respectively.

  The processing content of each step of the image data transmission method shown in the flowchart of FIG. 1 will be described together with the following embodiments of the image data transmission system of the present invention.

  First, a first embodiment of the image data transmission system of the present invention will be described.

  FIG. 2 is a schematic diagram showing the first embodiment of the image data transmission system of the present invention.

  The image data transmission system 10 shown in FIG. 2 includes an image data supply system 100 and an image forming apparatus 200.

  An image data supply system 100 shown in FIG. 2 includes a computer 110, a network 120, and an external controller 130. An image forming apparatus 200 includes an IIT (Image Input Terminal) 210 and an IPS (Image Processing System). Processing section) 220 and image forming section 230. The external controller 130 and the image forming unit 230 are connected to each other by a communication cable 300.

  In the external controller 130, first, image data stored in the computer 110 of the image data supply system 100 is transmitted to the image forming unit 230 via the communication cable 300. At this time, the image forming unit 230 receives this image data. In this case, the external controller 130 corresponds to an embodiment of the image data transmitting apparatus of the present invention, and the image forming unit 230 corresponds to an embodiment of the image data receiving apparatus of the present invention. The communication cable 300 corresponds to an example of the communication cable according to the present invention.

  In the IIT 210, red (R), green (G), and blue (B) three-color image data is acquired by reading a document. This image data is sent to the IPS 220 and converted into yellow (Y), magenta (M), cyan (C), and black (K) four-color image data suitable for image formation in the image forming unit 230. The image forming unit 230 performs image formation based on the YMCK four-color image data. Here, in transmission of RGB three-color image data from the IIT 210 to the IPS 220, the IIT 210 corresponds to an embodiment of the image data transmitting apparatus of the present invention, and the IPS 220 corresponds to an embodiment of the image data receiving apparatus of the present invention. To do. In the transmission of YMCK four-color image data from the IPS 220 to the image forming unit 230, the IPS 220 corresponds to an embodiment of the image data transmitting device of the present invention, and the image forming unit 230 of the image data receiving device of the present invention. This corresponds to one embodiment. Further, the RGB three-color image data passes through the IPS 220 and the image forming unit 230 and is transmitted to the external controller 130 via the communication cable 300 when instructed by the operator. In the external controller 130, the image data is received by the external controller 130. In this case, the IIT 210 corresponds to an embodiment of the image data transmitting apparatus of the present invention, and the external controller 130 corresponds to an embodiment of the image data receiving apparatus of the present invention.

  Next, a second embodiment of the image data transmission system of the present invention will be described.

  FIG. 3 is a schematic diagram showing a second embodiment of the image data transmission system of the present invention.

  Here, the image data transmission system 50 shown in FIG. 3 includes the internal controller 610 shown in FIG. 3 as an element that plays the role of the external controller 130 in the image data transmission system 10 shown in FIG. 2 is composed of elements equivalent to those of the image data transmission system 10 shown in FIG. Therefore, here, elements equivalent to those shown in FIG. 2 are denoted by the same reference numerals as those in FIG.

  The image data transmission system 50 shown in FIG. 3 includes an image data supply system 500 including a computer 110 and a network 120, and an image forming apparatus 600 including an IIT 210, an IPS 220, an image forming unit 230, and an internal controller 610. ing. In this image data transmission system 50, image data is transmitted from the internal controller 610 to the image forming unit 230, image data is transmitted from the IIT 210 to the IPS 220, image data is transmitted from the IPS 220 to the image forming unit 230, and The present invention is applied to an inter-module interface in the image forming apparatus 600 such as transmission of image data to the controller 610.

  Here, the internal controller 610, which is the difference between the first and second embodiments of the image data transmission system outlined with reference to FIGS. 2 and 3, is the same as the external controller 130 shown in FIG. The external controller 130 has the same function as that of the external controller 130 except that it is connected to the image forming unit 230 via the communication cable 300 but directly connected to the image forming unit 230. Therefore, in the following, details of the first and second embodiments will be described using the image data transmission system 10 of FIG. 2 as the first embodiment as a representative example. Further, matters specific to the image data transmission system 50 of FIG. 3 as the second embodiment will be supplemented as appropriate.

  First, the image data transmission system 10 will be described with reference to an example in which image data is transmitted from the external controller 130 to the image forming unit 230. Again, in this example, the external controller 130 corresponds to an embodiment of the image data transmitting apparatus of the present invention, and the image forming unit 230 corresponds to an embodiment of the image data receiving apparatus of the present invention.

  FIG. 4 is a functional block diagram showing details of the external controller and the image forming unit shown in FIG. 2 focusing on elements that operate when image data is transmitted from the external controller to the image forming unit.

  The external controller 130 in FIG. 4 transmits the image data V included in the computer 110 shown in FIG. 2 to the image forming unit 230. In FIG. A control unit 131, a clock generation unit 132, a transmission unit 133, an effective image data instruction unit 134, and a cable length acquisition unit 135 related to transmission are shown. Here, the clock generation unit 132, the transmission unit 133, and the effective image data instruction unit 134 correspond to examples of the clock generation unit, the transmission unit, and the effective image data instruction unit according to the present invention, respectively. Further, in the clock generation unit 132, the transmission unit 133, the effective image data instruction unit 134, and the cable length acquisition unit 135, the clock generation process (step S103), the transmission process (step S106), and the effective data instruction in the flowchart of FIG. A process (step S107) and a cable length acquisition process (step S102) are executed.

  4 executes an image forming process based on the image data V transmitted from the external controller 130. The image forming unit 230 includes a control unit 231, a transmission interruption unit 232, a transmission instruction unit 233, A reception processing unit 234 and a processing unit 235 are provided. Here, the control unit 231, the transmission interruption unit 232, and the processing unit 235 correspond to examples of the image data amount instruction unit, the transmission interruption unit, and the processing unit according to the present invention, respectively, and the transmission instruction unit 233 The reception processing unit 234 corresponds to an example of serving as both a transmission instruction unit and a transmission request unit according to the invention, and includes a reception unit, an excess image data discarding unit, an image data adding unit, and an invalid image data discarding unit according to the present invention. This is equivalent to one example. Further, the control unit 231, the transmission interruption unit 232, the transmission instruction unit 233, and the reception processing unit 234, respectively, the image data amount instruction process (step S101), the transmission interruption process (step S104), and the transmission instruction process in the flowchart of FIG. (Step S105) and a reception process (Step S108) are executed.

  First, prior to transmission of the image data V from the external controller 130 to the image forming unit 230, the following information is exchanged between the control unit 131 of the external controller 130 and the control unit 231 of the image forming unit 230. Done.

  In this embodiment, if the image data V representing an image composed of a plurality of two-dimensionally arranged pixels each having a pixel value is, for example, an A type image forming unit, it corresponds to an array of pixels for two rows. Data amount corresponding to the type of the image forming unit, such as a data amount corresponding to the arrangement of the pixels for one row, and so on. Is transmitted. Therefore, first, the type of the image forming unit is transmitted from the control unit 231 of the image forming unit 230 to the control unit 131 of the external controller 130. That is, the control unit 231 of the image forming unit 230 sends a data amount corresponding to the number of rows of pixels in one transmission according to the type of the image forming unit to the control unit 131 of the external controller 130. An image data amount instruction signal J1 instructing whether to transmit data is sent. The image data amount instruction signal J1 corresponds to an example of the image data amount instruction signal according to the present invention. Further, at this time, the control unit 231 of the image forming unit 230 sends information indicating the processing speed of the processing unit 235 that executes the image forming process in the image forming unit 230 to the control unit 131 of the external controller 130. Device information J2 indicating the type of the unit 230, that is, the clock frequency range necessary for transmitting the data format and image data is also sent.

  In this embodiment, a plurality of communication cables 300 having different lengths are prepared in advance, and the external controller 130 and the image forming unit 230 are connected by the communication cable 300 appropriately selected by the user from among them. Is done. Here, the predetermined two contacts in the connector on the external controller 130 side of each communication cable 300 are electrically connected to each other in the connector, and which contact is electrically connected to each other differs depending on each communication cable 300. ing.

  In the cable length acquisition unit 135 shown in FIG. 4, which contact is conductive in the connector of the communication cable 300 currently connected to the external controller 130 is detected as information indicating the length of the communication cable 300. The detection result J3 is transmitted to the control unit 131.

  The control unit 131 of the external controller 130 first determines the clock frequency based on the device information J2, the detection result J3 in the cable length acquisition unit 135, and the data format of the image data V to be transmitted. A storage unit (not shown) of the control unit 131 stores a plurality of combinations of device information J2, a detection result J3, and a data format with different contents, and a clock frequency corresponding to each combination on a one-to-one basis. Thus, the control unit 131 searches the storage unit using the three pieces of input information, and selects a clock frequency corresponding to the three pieces of information.

  Here, the clock frequency corresponding to each combination described above, which is stored in a storage unit (not shown) of the control unit 131, is obtained as follows when the external controller 130 is designed.

  The detection result J3 is information corresponding to the length of each of the plurality of communication cables 300 having different lengths prepared in advance in the image data transmission system 10 shown in FIG. The upper limit value of the clock frequency is obtained from a predetermined communication standard adopted in the data transmission system 10. The device information J2 is information corresponding to the processing speed of the processing unit 235 of the image forming unit 230, and the lower limit value of the clock frequency is obtained from this information and the data format. The clock frequency corresponding to the three pieces of information of the device information J2, the detection result J3, and the data format can take any value between the upper limit value and the lower limit value obtained from these three pieces of information. A central value between the upper limit value and the lower limit value is employed. Then, the clock frequency is obtained for each of a plurality of combinations having the above three information and different contents.

  On the other hand, from the image data amount instruction signal J1 input to the control unit 131 together with the device information J2, the data amount of the image data V sent by the transmission unit 133 at one time is obtained as follows. That is, from the size of the image represented by the image data V to be transmitted and the information such as how many rows of pixels are to be transmitted at one transmission indicated by the image data amount instruction signal J1, The number of pixels of image data V to be transmitted at one transmission is calculated.

  As described above, the control unit 131 determines the clock frequency and the number of pixels to be transmitted at one transmission, and sends them to the clock generation unit 132 and the transmission unit 133, respectively.

  In the clock generation unit 132, the reference clock CL having the above clock frequency is generated and sent to the transmission unit 133.

  In this embodiment, the reference clock CL is generated in the apparatus that transmits the image data V in this way. Thereby, since the reference clock in which the deterioration of the waveform quality is suppressed can be used for the transmission of the image data V, the image data V can be transmitted accurately. In this embodiment, as will be described later, the reference clock CL is also transmitted together with the image data V. The transmission path for the reference clock CL is a reception process of the image forming unit 230 from the transmission unit 133 of the external controller 130. Only one direction toward the part 234 is sufficient. As a result, the transmission path is simplified. For example, the cost for configuring the transmission path with a cable, a connector, or the like is suppressed. Further, with the simplification of the transmission path for the reference clock, electromagnetic noise related to the reference clock is reduced. Further, when designing the external controller 130 in the present embodiment, various information such as the clock frequency of the reference clock CL used for transmission of the image data V can be easily obtained from the built-in clock generation unit 132, and the design work is simplified. Design cost can be reduced.

  With the processing described so far, the preparation for transmission of the image data V in the external controller 230 is completed.

  On the other hand, in the control unit 231 of the image forming unit 230, after the image data amount instruction signal J1 and the device information J2 are sent to the control unit 131 of the external controller 130, the external controller 130 performs the data transmission preparation process. After the time estimated to be required has elapsed, an instruction is sent to the transmission instruction 233 to send the following signal to the transmission unit 133 of the external controller 130.

  That is, the transmission instruction unit 233 receives two instructions from the control unit 231 and requests the transmission unit 133 of the external controller 130 to transmit the image data V in two ways, such as the page sync signal PS and the line sync signal LS. The signal is sent to the transmission unit 133. Here, a combination of these two signals corresponds to an example of a transmission instruction signal according to the present invention. Hereinafter, these two signals will be described with reference to other drawings. In the following description, the constituent elements shown in FIG. 4 will be referred to without particularly referring to the figure numbers.

  FIG. 5 is a schematic diagram showing a page sync signal and a line sync signal.

  The page sync signal PS shown in FIG. 5 is a negative logic signal, and is sent to the transmission unit 133 of the external controller 130 during the period AS (assertion period) in which the level of the page sync signal PS is low. This is a signal for instructing to transmit image data V to a line sync signal LS, which will be described later. The assert period AS in the page sync signal PS corresponds to a period in which the line sync signal LS corresponding to the transmission instruction for the image data V for one page is transmitted.

  The line sync signal LS shown in FIG. 5 is also a negative logic signal similar to the page sync signal PS, and is composed of a plurality of periodically generated pulses. The line sync signal LS is a signal that instructs the transmission unit 133 of the external controller 130 to transmit the image data V at the falling timing τ of each pulse constituting the line sync signal LS. For example, when the image data amount instruction signal J1 transmits image data V having a data amount corresponding to the pixel arrangement for one row at one transmission, the line sync signal LS rises. At each downstream timing τ, image data V having a data amount corresponding to the arrangement of pixels for one row is transmitted from the transmission unit 133 of the external controller 130.

  The time interval between the pulses in the respective signals PS and LS when the transmission instructing unit 233 sends the page sync signal PS and the line sync signal LS to the transmission unit 133 of the external controller 130 as described above is the present implementation. In the embodiment, the time interval is set such that the processing unit 235 of the image forming unit 230 can sufficiently execute the image forming process. Accordingly, the image forming unit 230 can receive the image data V at time intervals according to the processing capability of the image forming unit 230.

  Returning again to FIG. 4, the description will be continued.

  When the page sync signal PS and the line sync signal LS are transmitted from the transmission instruction unit 233 of the image forming unit 230 to the transmission unit 133 of the external controller 133, the reception processing of the image forming unit 230 is performed from the transmission unit 133. Image data V is transmitted toward the unit 234 at the timing instructed by these both signals. At this time, the image data V is transmitted to the reception processing unit 234 in synchronization with the reference clock CL transmitted from the clock generation unit 132. At this time, the reference clock CL is also transmitted to the reception processing unit 234 together with the image data V. Further, the data amount of the image data V transmitted at each falling timing τ of the line sync signal LS is obtained by the control unit 131 of the external controller 133 based on the image data amount instruction signal J1. This is the amount of data corresponding to the number of pixels transmitted during one transmission.

  As described above, when the transmission of the image data V is started from the transmission unit 133, the valid image data instruction unit 134 generates the following valid signal VA based on the instruction of the control unit 131, and the image data V And the reference clock CL are transmitted to the reception processing unit 234 of the image forming unit 230. Here, the valid signal VA corresponds to an example of an effective image data instruction signal according to the present invention. Hereinafter, details of the image data V, the reference clock CL, and the valid signal VA transmitted to the reception processing unit 234 will be described with reference to the accompanying drawings. In the following description, the constituent elements shown in FIG. 4 will be referred to without particularly referring to the figure numbers.

  FIG. 6 is a schematic diagram showing image data, a reference clock, and a valid signal together with a line sync signal. FIG. 7 is a schematic diagram showing a relationship between the image data and the image.

  FIG. 6 shows the image data V, the reference clock CL, and the valid signal VA transmitted at one falling timing τ in the line sync signal LS. Here, hereinafter, for convenience of explanation, the data amount of the image data V transmitted at one timing τ is described as a data amount corresponding to the number of pixels for one row.

  Image data V shown in FIG. 6 represents an image composed of a plurality of pixels arranged two-dimensionally each having a pixel value, and is a pixel signal Vs which is a digital signal of a predetermined bit representing each pixel value. Are arranged. FIG. 7 schematically shows an image G composed of a plurality of pixels Gs. However, each pixel signal Vs constituting the image data V in FIG. 6 corresponds to the density of each pixel Gs shown in FIG. Print) data.

  As described above, the image data V is synchronized with the reference clock CL, and each pixel signal Vs constituting the image data V corresponds to each clock pulse Cp constituting the reference clock CL. That is, each pixel signal Vs is transmitted according to the falling timing τC of each clock pulse Cp in the reference clock CL, which is a negative logic signal.

  Further, as described above, in the example of FIG. 6, image data V having a data amount corresponding to the pixel array GL for one row in FIG. 7 is transmitted at each timing τ. Then, a valid signal VA indicating which portion of the image data V that is the array of the pixel signals Vs corresponds to the pixel array GL for one row shown in FIG. 7 is generated and transmitted by the effective image data instruction unit 134. . In the present embodiment, in the reception processing unit 234 of the image forming unit 230, the arrangement of the pixel signals Vs sent during the period VAe in which the level of the valid signal VA that is a negative logic signal is low is represented by the image data V Are recognized as valid parts.

  Returning again to FIG. 4, the description will be continued.

  As described above, in the image forming unit 230, the transmission instruction unit 233 receives the line sync signal LS that instructs the transmission unit 133 of the external controller 130 to transmit the image data V at the falling timing of the negative logic pulse. Sent from In the transmission interruption unit 232 provided in the image forming unit 230, the transmission instruction unit 233 is instructed to interrupt transmission of the line sync signal LS. Hereinafter, the operation of the transmission interruption unit 232 will be described with reference to another drawing. In the following description, FIG. 4 will be referred to without changing the figure number.

  FIG. 8 is a diagram illustrating a state in which transmission of the line sync signal is interrupted.

  FIG. 8 shows the page sync signal PS and the line sync signal LS also shown in FIG. 5. In FIG. 8, the transmission of the pulse in the line sync signal LS is the first in the figure. It is shown that the operation is interrupted at the timing T1 and resumed at the second timing T2. However, even if transmission of the line sync signal LS is interrupted, the page sync signal PS continues to be transmitted in the low level state (asserted state). As a result, the transmission unit 133 of the external controller 130 transmits the image data V in the line corresponding to the pulse P1 immediately before the interruption in the line sync signal LS until the next pulse P2 is transmitted. Is stopped and the restart pulse P2 is sent, the image data V corresponding to the next row of the row corresponding to the previous pulse P1 is sent.

  As described above, the processing by the transmission interrupting unit 232 described above is, for example, that the processing of components (not shown) in the image forming unit 230 becomes very busy, and the image data V transmitted from the transmitting unit 133 of the external controller 130 is temporarily stored. This is executed based on an instruction from the control unit 231 when processing cannot be performed automatically.

  Returning again to FIG. 4, the description will be continued.

  As described above, the reception processing unit 234 of the image forming unit 230 is instructed by the above-described image data amount instruction signal J1 such as corresponding to one row of pixels at each falling timing in the line sync signal LS. The image data V having the data amount thus received is received. Here, as described above, the data amount of the image data V transmitted by the transmission unit 133 of the external controller 130 at a time is calculated by the control unit 131 of the external controller 130 based on the image data amount instruction signal J1. At this time, a calculation error may occur in the calculation process in the control unit 131. Based on the calculation result, the data amount of the image data V transmitted by the transmission unit 133 of the external controller 130 at a time is the image data amount. The amount of data indicated by the instruction signal J1 is not necessarily exactly the same.

  In this embodiment, depending on the image data to be transmitted, when the transmission unit 133 transmits the image data V, a transmission method such as performing compression processing for each image data of a predetermined number of pixels is used. Sometimes. In this case, the data amount of the image data V transmitted by the transmission unit 133 of the external controller 130 at a time is inevitably a data amount corresponding to the number of pixels that is an integral multiple of the predetermined number of pixels, and the image data amount instruction is not necessarily provided. The amount of data indicated by the signal J1 is not always transmitted accurately.

  In the present embodiment, the following processing is executed when the reception processing unit 234 receives image data V having a data amount different from the data amount instructed by the image data amount instruction signal J1 for the reasons described above. The Hereinafter, processing executed in the reception processing unit 234 will be described with reference to another drawing. In this description, the elements shown in FIG.

  FIG. 9 is a diagram for explaining processing executed by the reception processing unit when image data having a data amount different from the data amount instructed by the image data amount instruction signal is received.

  In FIG. 9, three examples of the image data V having a data amount different from the data amount indicated by the image data amount instruction signal J1 are shown together with the valid signal VA.

  First, part (A) of FIG. 9 shows an example in which an extra pixel signal Vs for two pixels is transmitted even though the low level period VAe in the valid signal VA has ended. In this case, the reception processing unit 234 discards the extra pixel signal Vsn for two pixels as invalid image data.

  Further, in part (B) of FIG. 9, the image data V is transmitted in a state where the pixel signal for two pixels is insufficient, even though the low level period VAe in the valid signal VA continues. It is shown. In this case, in the reception processing unit 234, predetermined image data Vsp indicating a white image is added in order to compensate for the pixel signals for the two missing pixels.

  Furthermore, in part (C) of FIG. 9, although the image data V transmitted by the transmission unit 133 is data that completely matches the valid signal VA, the data amount of the image data V is the image data. In the example, the amount instruction signal J1 exceeds the specified data amount. This example corresponds to a case where the transmission unit 133 transmits the image data V after performing the compression processing as described above. For example, when this compression processing is executed in units of 8 pixels, the transmitted image data is composed of pixel signals Vs that is an integer multiple of “8”. At this time, if the data amount indicated by the image data amount instruction signal J1 is, for example, a data amount corresponding to the pixel array of “37”, the transmission unit 133 is closest to “37” and “37”. The image data V including the pixel signal Vs of “40” that is an integer multiple of “8” larger than “8” is transmitted. Part (C) of FIG. 9 shows an example in which extra pixel signals Vsn for three pixels are transmitted as a result of such transmission processing. In this case, the reception processing unit 234 discards the extra pixel signal Vsn for three pixels as excess image data.

  Through the processing in the reception processing unit 234 described above, the processing unit of the image forming unit 230 executes the image forming process based on the image data V having the data amount exactly equal to the data amount instructed by the image data amount instruction signal J1. The

  Up to this point, the case where image data is transmitted from the external controller 130 to the image forming unit 230 in the image data transmission system 10 illustrated in FIG. 1 has been described with reference to FIGS. 4 to 9. In the image data transmission system 10, image data acquired by reading a document with the IIT 210 in FIG. 1 may be transmitted from the IIT 210 to the external controller 130. The external controller 130 includes an element that receives image data at this time.

  FIG. 10 is a functional block diagram showing details of the external controller and IIT shown in FIG. 2 by focusing on elements that operate when image data is transmitted from the IIT to the external controller.

  Here, the various functions related to the reception of the image data V in the external controller 130 were responsible for the various functions related to the reception of the image data V in the image forming unit 230 shown in FIG. 4. The transmission interruption unit 232 and the transmission instruction unit 233. , And the elements equivalent to the reception processing unit 234. The functions related to the transmission of the image data V in the IIT 210 were responsible for the functions related to the transmission of the image data V in the external controller 130. The clock generation unit 132, the transmission unit 133, and the effective image data instruction shown in FIG. It is carried by elements equivalent to the part 134 and the cable length acquisition part 135. Therefore, here, elements equivalent to those shown in FIG. 4 are denoted by the same reference numerals in FIG. 10 as those in FIG.

  In FIG. 10, the control unit 131 of the external controller 130 executes control on the transmission interruption unit 232, the transmission instruction unit 233, and the reception processing unit 234. Since it is the same as the content of the control performed in the control part 231 of the part 230, duplication description is abbreviate | omitted here. Further, the control content of the control unit 211 provided in the IIT 210 is the same as the control content executed in the external controller 130 of FIG.

  The relationship between the external controller 130 and the IIT 210 described with reference to FIG. 10 also exists between the internal controller 610 and the IIT 210 shown in FIG. 4, and the internal controller 610 is similar to the external controller 130 in the image data. Needless to say, it has various elements involved in the reception.

  Further, as described above, the RGB three-color image data acquired by the IIT 210 shown in FIG. 2 or FIG. Data is transmitted from the IPS 220 to the image forming unit 230. Here, since the transmission from the IIT 210 to the IPS 220 and the transmission from the IPS 220 to the image forming unit 230 are directly connected without using a communication cable or the like, the internal controller 610 shown in FIG. This is the same as the transmission of image data at the interface between modules in the image forming apparatus 600 such as between the image forming unit 230 and the IIT 210. Hereinafter, as an example of transmission of image data in such an inter-module interface, transmission from the IPS 220 to the image forming unit 230 is given, and elements involved in such transmission are shown in another figure.

  FIG. 11 is a functional block diagram showing details of the IPS and the image forming unit shown in FIG. 2 or FIG. 3, focusing on elements that operate when image data is transmitted from the IPS to the image forming unit also shown in FIG. FIG.

  Functions related to the transmission of the image data V in the IPS 220 are assigned to elements equivalent to the clock generation unit 132, the transmission unit 133, and the effective image data instruction unit 134 among the elements included in the external controller 130 illustrated in FIG. It has been broken. These elements are also elements responsible for various functions relating to transmission of the image data V in the internal controller 610 shown in FIG. Therefore, here, elements equivalent to those shown in FIG. 4 are denoted by the same reference numerals in FIG. 11 as those in FIG.

  As described above with reference to FIGS. 1 to 11, according to the embodiment of the image data transmission method of the present invention and the image data transmission systems 10 and 50 of the first and second embodiments of the present invention. For example, the reference clock generated by the clock generation unit built in the image data transmission side and suppressed in the deterioration of the waveform quality is used for the transmission of the image data, so that the image data can be transmitted accurately. Furthermore, according to these embodiments, by incorporating the reference clock generation unit on the image data transmission side in this way, the transmission path related to the reference clock is simplified, and the cost is reduced, and the reference clock is involved. Various effects such as reduction of electromagnetic noise and reduction of design cost associated with simplification of design work can also be obtained.

  In the above description, the transmission instruction unit 233 that transmits the line sync signal LS composed of a plurality of periodically generated pulses has been described as an example of the transmission instruction unit according to the present invention. It is not limited to. The transmission instruction unit of the present invention may be, for example, a unit that changes the transmission speed on the image data transmission side by changing the generation period of each pulse constituting the line sync signal LS. In this example, for example, if the generation period of each pulse is shortened, the transmission speed on the transmission side is increased, and if the generation period of each pulse is increased, the transmission speed on the transmission side is decreased.

  Further, in the above description, as an example of the transmission instruction unit according to the present invention, transmission for transmitting the line sync signal LS to the image data transmission side unless there is an interruption instruction from the transmission interruption unit according to the present invention. Although the instruction unit has been illustrated and described, the present invention is not limited to this. For example, the transmission instruction unit of the present invention transmits a line sync signal only when the receiving side of the image data is in a state where the received image data can be reliably processed. For example, the transmission of the line sync signal may not be interrupted until the transmission of the image data is completed.

It is a flowchart which shows one Embodiment of the image data transmission method of this invention. 1 is a schematic diagram showing a first embodiment of an image data transmission system of the present invention. It is a schematic diagram which shows 2nd Embodiment of the image data transmission system of this invention. FIG. 3 is a functional block diagram showing details of an external controller and an image forming unit shown in FIG. 2 by focusing on elements that operate when image data is transmitted from the external controller to the image forming unit. It is a schematic diagram which shows a page sync signal and a line sync signal. It is a schematic diagram which shows image data, a reference clock, and a valid signal with a line sync signal. It is a schematic diagram which shows the relationship between image data and an image. It is a figure which shows a mode that transmission of the line sync signal was interrupted. It is a figure explaining the process performed when the image data of the data amount different from the data amount which the reception process part instruct | indicated with the image data amount instruction | indication signal was received. FIG. 3 is a functional block diagram showing details of the external controller and the IIT shown in FIG. 2 by focusing on elements that operate when image data is transmitted from the IIT to the external controller. FIG. 4 is a functional block diagram showing details of the IPS and the image forming unit shown in FIG. 2 or 3 by focusing on elements that operate when image data is transmitted from the IPS to the image forming unit also shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image data transmission system 100 Image data supply system 110 Computer 120 Network 130 External controller 131 Control part 132 Clock generation part 133 Transmission part 134 Effective image data instruction part 135 Cable length acquisition part 200 Image forming apparatus 210 IIT
211 Control unit 220 IPS
230 Image forming unit 231 Control unit 232 Transmission interruption unit 233 Transmission instruction unit 234 Reception unit 235 Processing unit 500 Image data supply system 600 Image forming apparatus 610 Internal controller

Claims (14)

An image data receiving apparatus that receives image data representing an image, and an image data transmitting apparatus that transmits the image data to the image data receiving apparatus in response to a transmission request for the image data from the image data receiving apparatus In data transmission systems,
The image data transmitting device is
A clock generator for generating a reference clock having a predetermined frequency;
An image data transmission system comprising: a transmission unit that transmits the image data in synchronization with the reference clock. This image data transmission system performs transmission / reception of the image data in accordance with a predetermined communication standard,
The image data receiving apparatus includes a processing unit that performs data processing on the received image data at a predetermined processing speed,
2. The image data transmission system according to claim 1, wherein the clock generation unit generates a reference clock having a frequency corresponding to both the communication standard and the processing speed of the processing unit. The image data transmitting device and the image data receiving device are connected by a predetermined communication cable,
The image data receiving apparatus includes a processing unit that performs data processing on the received image data at a predetermined processing speed,
2. The image data transmission system according to claim 1, wherein the clock generation unit generates a reference clock having a frequency corresponding to both the length of the communication cable and the processing speed of the processing unit. When the image data receiving apparatus makes a transmission request for the image data to the image data transmitting apparatus, a transmission instruction signal for instructing the transmission timing of the image data is periodically transmitted to the transmitting unit of the image data transmitting apparatus. Is provided with a transmission instruction section to transmit to
The image data transmission system according to claim 1, wherein the transmission unit transmits image data every time the transmission instruction signal is received. This image data transmission system performs transmission / reception of pixel value data representing pixel values of a plurality of pixels arranged two-dimensionally each having a pixel value as the image data,
Each time the transmission unit of the image data transmission device receives the transmission instruction signal, the transmission unit transmits pixel value data for one row in which pixel values of pixels for one row are collected. The image data transmission system according to claim 4.   5. The image data transmission system according to claim 4, wherein the image data receiving apparatus includes a transmission interruption unit that temporarily interrupts transmission of the transmission instruction signal in the transmission instruction unit. An image in which the image data receiving device transmits an image data amount instruction signal for instructing an amount of image data to be transmitted by the transmitting unit to the transmitting unit of the image data transmitting device every time the transmitting unit receives the transmission instruction signal. A data amount indicating unit,
The transmission unit of the image data transmission device transmits data having a data amount that may further include a quantitative error in the data amount indicated by the image data amount instruction signal.
The image data receiving device, when image data having a data amount exceeding the data amount indicated by the image data amount instruction signal is transmitted from the transmission unit at one transmission timing, 5. The image data transmission system according to claim 4, further comprising an excess image data discarding unit that discards excess image data.   When the image data receiving device transmits image data having a data amount smaller than the data amount indicated by the image data amount instruction signal from the transmission unit of the image data transmitting device at one transmission timing, An image data adding unit for adding the data amount corresponding to the difference between the two to the data amount of the image data to match the data amount of the received image data with the data amount indicated by the image data amount instruction signal; 8. The image data transmission system according to claim 7, wherein the image data transmission system is an image data transmission system. The image data transmitting apparatus transmits an effective image data instruction signal indicating which image data is valid image data among the image data transmitted by the transmitting unit at one transmission timing to the image data receiving apparatus. With an effective image data instruction unit
Image data other than the image data indicated by the effective image data instruction signal among the image data transmitted from the transmission unit at one transmission timing by the image data receiving device. 2. The image data transmission system according to claim 1, further comprising an invalid image data discarding unit that discards the image as invalid image data. In an image data transmitting apparatus for transmitting the image data to the image data receiving apparatus in response to a transmission request for the image data from an image data receiving apparatus for receiving image data representing an image,
A clock generator for generating a reference clock having a predetermined frequency;
An image data transmission apparatus comprising: a transmission unit that transmits the image data in synchronization with the reference clock. In an image data receiving apparatus for receiving image data representing an image,
A transmission request unit that performs only a transmission request among a transmission request of the image data and a transmission of a reference clock synchronized with the image data to an image data transmission device that transmits image data;
The image data transmitting device includes a receiving unit that receives image data transmitted in synchronization with a reference clock internally generated in the image data transmitting device in response to the transmission request. Receiver device. Between an image data receiving apparatus that receives image data representing an image and an image data transmitting apparatus that transmits the image data to the image data receiving apparatus in response to a transmission request for the image data from the image data receiving apparatus In the image data transmission method,
A clock generation process for generating a reference clock having a predetermined frequency in the image data transmitting device;
A transmission process of transmitting the image data in synchronization with the reference clock;
An image data transmission method comprising: a reception process of receiving image data transmitted in synchronization with the reference clock in the transmission process. In an image data transmitting method for transmitting the image data to the image data receiving apparatus in response to a transmission request for the image data from an image data receiving apparatus that receives image data representing an image,
A clock generation process for generating a reference clock of a predetermined frequency;
And a transmission process of transmitting the image data in synchronization with the reference clock. In an image data receiving method for receiving image data representing an image,
A transmission request process for performing only a transmission request among a transmission request for the image data and a transmission of a reference clock synchronized with the image data to an image data transmission apparatus that transmits image data;
An image data receiving method comprising: a receiving process in which the image data transmitting apparatus receives image data transmitted in synchronization with a reference clock internally generated in the image data transmitting apparatus in response to the transmission request. .

Images