Printing apparatus, printing method, and computer program

Abstract

To provide a printing apparatus capable of suppressing a decrease in efficiency of a transmitting process of image data, and to provide a printing method and a computer program.SOLUTION: There is provided a printing apparatus including: a main control circuit; and sub-control circuits connected in series to each other and configured to transmit print data transmitted by the main control circuit, from upstream to downstream. Each of the sub-control circuits is configured to: store information indicating transmitting methods of the print data; and transmit the print data downstream, by the one of the transmitting methods indicated by the information, in a case where the print data is received.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present technology relates to a printing apparatus, a printing method, and a computer program including a main control circuit and a plurality of sub-control circuits connected in series.

Background Art

[0002] A droplet ejection apparatus including a plurality of head substrates for driving a head and a plurality of head control substrates (sub-control circuits) for controlling the plurality of head substrates has been proposed. The plurality of head control substrates are connected in a daisy chain. A main controller (main control circuit) transmits image data (print data) to the head control substrate located at the upstream end. Each head control substrate transmits the print data downstream and controls each head substrate (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When each head control substrate receives image data from upstream, it stores the image data corresponding to itself and transmits the image data not corresponding to itself downstream. If the efficiency of the transmission process of the image data decreases, printing may take a long time.

[0005] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a printing apparatus, a printing method, and a computer program capable of suppressing a decrease in the efficiency of the transmission process of image data.

Means for Solving the Problems

[0006] A printing apparatus according to an embodiment of the present disclosure includes a main control circuit and a plurality of sub-control circuits connected in series to transmit printing data transmitted by the main control circuit from upstream to downstream. Each sub-control circuit stores information indicating a transmission method of the printing data, and when receiving the printing data, transmits the printing data downstream according to the transmission method indicated by the information.

[0007] A printing method according to an embodiment of the present disclosure is a printing method executed by a printing apparatus including a main control circuit and a plurality of sub-control circuits connected in series to transmit printing data transmitted by the main control circuit from upstream to downstream. Each sub-control circuit stores information indicating a transmission method of the printing data, and when receiving the printing data, transmits the printing data downstream according to the transmission method indicated by the information.

[0008] A computer program according to an embodiment of the present disclosure is a computer program executed by a printing apparatus including a main control circuit and a plurality of sub-control circuits connected in series to transmit printing data transmitted by the main control circuit from upstream to downstream. Each sub-control circuit is caused to store information indicating a transmission method of the printing data, and when receiving the printing data, execute a process of transmitting the printing data downstream according to the transmission method indicated by the information.

Advantages of the Invention

[0009] In the printing apparatus, printing method, and computer program according to an embodiment of the present disclosure, information indicating a transmission method of printing data is stored, and when receiving the printing data, the printing data is transmitted downstream according to the transmission method indicated by the information. For example, when the information indicates a method of transmitting the printing data without storing it, the sub-control circuit, when receiving the printing data from upstream, transmits it downstream without storing it in its own storage unit, and can suppress a decrease in the efficiency of the printing data transmission process.

Brief Description of the Drawings

[0010]

Figure 1

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Figure 17

Mode for Carrying Out the Invention

[0011] (Embodiment 1) Hereinafter, the present invention will be described based on the drawings showing the printing apparatus 1 according to Embodiment 1. FIG. 1 is a schematic plan view of the printing apparatus 1. In FIG. 1, the conveyance direction of the recording paper 100 corresponds to the front-rear direction of the printing apparatus 1. Also, the width direction of the recording paper 100 corresponds to the left-right direction of the printing apparatus 1. The recording paper 100 corresponds to a recording medium. Also, the direction orthogonal to the front-rear direction and the left-right direction, that is, the direction perpendicular to the paper surface of FIG. 1 corresponds to the up-down direction of the printing apparatus 1.

[0012] As shown in FIG. 1, the printing apparatus 1 includes a platen 3 housed in a case 2, four inkjet heads 4, two conveyance rollers 5 and 6, and a control device 7 and the like. The upper surface of the platen 3 is passed through by the recording paper 100. The four inkjet heads 4 are arranged in the conveyance direction above the platen 3. Each inkjet head 4 is a so-called line type head. Ink is supplied to the inkjet head 4 from an ink tank (not shown). Different colors of ink are supplied to the four inkjet heads 4.

[0013] As shown in FIG. 1, the two conveyance rollers 5 and 6 are respectively arranged on the rear side and the front side with respect to the platen 3. The two conveyance rollers 5 and 6 are respectively driven by a motor (not shown) and convey the recording paper 100 on the platen 3 forward. The two conveyance rollers 5 and 6 correspond to a conveyance unit. The control device 7 controls the printing apparatus 1 based on a control program. The control device 7 is connected to an external device 9 such as a PC so as to be capable of data communication, and drives each part of the printing apparatus 1 based on the print data transmitted from the external device 9 to execute printing.

[0014] FIG. 2 is a plan perspective view of the inkjet head 4. The inkjet head 4 includes a plurality of heads 42. The heads 42 correspond to head units. The plurality of heads 42 are arranged in two rows in the front-rear direction. In the front row, four heads 42 are arranged along the left-right direction, and in the rear row, five heads are arranged along the left-right direction. A plurality of nozzles 42a are provided on the lower surface of the head 42. Note that the number and the number of rows of the heads 42 are not limited and can be changed.

[0015] FIG. 3 is a block diagram of the control device 7 and the inkjet head 4. The control device 7 includes a main control circuit 7a. The main control circuit 7a includes a control unit 7b, a main storage unit 7c, an auxiliary storage unit 7d, and a communication interface (I / F) 7e. The control unit 7b includes a logic circuit, such as an FPGA or an ASIC. Note that the control unit 7b may include a processor, such as a CPU, an MPU, or a GPU. The main storage unit 7c is, for example, a RAM.

[0016] Examples of the main storage unit include a RAM. Examples of the auxiliary storage unit include a ROM and a rewritable storage medium, such as an EEPROM, an EPROM, a hard disk, etc. A control program, a predetermined capacity, etc. to be described later are stored in the auxiliary storage device. The control unit 7b reads out and executes a control program from the auxiliary storage unit to the main storage unit, for example. The control program may be installed in the auxiliary storage unit from a recording medium 70 (see FIG. 1), such as an optical disk or a portable flash memory. Note that the control program may be downloaded to the auxiliary storage unit from a server connected to the printing device 1 via a communication network. The communication I / F 7d is connected to a communication cable 50. The control device 7 controls the printing device 1 based on the control program.

[0017] The inkjet head 4 includes a plurality of head modules 40. The plurality of head modules 40 are arranged in a line, for example, in the left - right direction. The plurality of head modules 40 have, for example, a first head module 40(1), a second head module 40(2), ···, an nth head module 40(n) (n is a natural number). The first head module 40(1) is located at the leftmost position, and the nth head module 40(n) is located at the rightmost position. The first head module 40(1) is at the position closest to the control device 7 among all the head modules 40, and the nth head module 40(n) is at the position farthest from the control device 7 among all the head modules 40.

[0018] Each of the first head module 40(1) to the nth head module 40(n) includes a sub - control circuit 41, a head 42, an upstream - side I / F 43a, and a downstream - side I / F 43b. The plurality of heads 42 correspond to a head group. The sub - control circuit 41 includes a control unit 41a, a main memory unit 41b, and an auxiliary memory unit 41c. The sub - control circuit 41 includes, for example, an ASIC or an SoC. The plurality of sub - control circuits 41 correspond to a sub - control circuit group.

[0019] The control unit 41a controls the operation of the sub - control circuit 41. The control unit 41a may include a processor such as a CPU, or may include a logic circuit such as an FPGA. The main memory unit 41b is, for example, a RAM. The main memory unit 41b includes a storage area 45.

[0020] The auxiliary memory unit 41c is a rewritable non - volatile memory such as a flash ROM or an EEPROM. Hereinafter, the sub - control circuits 41 of the first head module 40(1) to the nth head module 40(n) are also referred to as sub - control circuits 41(1) to sub - control circuits 41(n), and the storage areas 45 of the first head module 40(1) to the nth head module 40(n) are also referred to as storage areas 45(1) to storage areas 45(n).

[0021] Each of the I / Fs 7e, 43a, and 43b is a bidirectional communication-capable interface and is connected in series by a connector and a communication cable 50. The I / F 7e transmits print data to the I / F 43a of the sub-control circuit 41(1). The I / F 43b of the sub-control circuit 41(1) transfers the print data to the I / F 43a of the sub-control circuit 41(2), and the I / F 43b of the sub-control circuit 41(2) transmits it to the I / F 43a of the sub-control circuit 41(3). In this way, the print data is sequentially transferred up to the I / F 43a of the sub-control circuit 41(n). Each sub-control circuit 41 drives the head 42 based on the print data and ejects ink.

[0022] FIG. 4 is a conceptual diagram showing the storage area 45 of the sub-control circuit 41. The storage area 45 includes a first storage area 45a that stores information indicating the transmission method of print data and a second storage area 45b that stores print data.

[0023] The transmission method of print data includes, for example, a first transmission method in which when the k-th sub-control circuit (k is a natural number from 1 to n - 1) receives print data, it stores the k-th data included in the received print data and transmits the remaining print data excluding the k-th data to the downstream side, and a second transmission method in which the entire received print data is transmitted to the downstream side as it is. For example, the information indicating the first transmission method is 0, and the information indicating the second transmission method is 1. When 0 is stored in the first storage area 45a, the sub-control circuit 41 transmits the print data to the downstream side by the first transmission method, and when 1 is stored in the first storage area 45a, the sub-control circuit 41 transmits the print data to the downstream side by the second transmission method.

[0024] The main control circuit 7a transmits the print data of multiple lines to the sub-control circuit 41(1) in order for each line. The main control circuit 7a divides the print data of one line into a plurality of data units, that is, generates a plurality of data units from the print data of one line, and transmits each data unit to the sub-control circuit 41(1) in order. In other words, the print data of one line includes a plurality of data units, and the main control circuit 7a transmits each data unit to the sub-control circuit 41(1) in order. Note that the division process of dividing the print data of one line into a plurality of data units is executed at an appropriate timing. For example, when receiving print data from the external device 9, the division process may be executed at all times, or when the free capacity of the main storage unit 41b of each sub-control circuit 41 is equal to or greater than a predetermined capacity, the division process is not executed, and when the free capacity of the main storage unit 41b is less than the predetermined capacity, the division process may be executed.

[0025] In this embodiment, the main control circuit 7a transmits the print data for 9 lines. In the initial state, the main control circuit 7a divides the print data for one line into two data units. That is, the print data for one line includes a first data unit and a second data unit. In the initial state, the data amount of the first data unit is smaller than the free capacity of the second storage area 45b of the sub-control circuit 41(1), and the data amount of the second data unit is smaller than the free capacity of the second storage area 45b of the sub-control circuit 41(1). Note that the main control circuit 7a may transmit the print data for 10 lines or more or 8 lines or less. The main control circuit 7a may divide the print data for one line into three or more data units, or may make the print data for one line into one data unit without division.

[0026] Also, in this embodiment, the number of sub-control circuits 41 is nine. That is, n = 9. The first data unit includes data D1 to data D5 corresponding to the sub-control circuits 41(1) to 41(5). The second data unit includes data D6 to data D9 corresponding to the sub-control circuits 41(6) to 41(9). That is, the main control circuit 7a generates the first data unit and the second data unit.

[0027] The second data unit is a data unit that includes the most upstream data D6 from the remaining print data obtained by excluding the generated data unit (the first data unit) from one line of print data. Data D1 corresponds to the first data. Data D6 corresponds to the s-th data.

[0028] After the main control circuit 7a executes the transmission process of the first data unit, that is, data D1 to data D5, it executes the transmission process of the second data unit, that is, data D6 to data D9. In other words, the main control circuit 7a executes a transmission process of transmitting data D1 to data D9 from the upstream data to the sub-control circuit 41(1). Note that the number of sub-control circuits 41 may be 8 or less or 10 or more.

[0029] The transmission process of the print data in each sub-control circuit 41 will be described. FIG. 5 is a conceptual diagram showing the storage area 45(1) of the most upstream sub-control circuit 41(1) when receiving the print data of the first line. As shown in FIG. 5(1), in the initial state, 0 is stored in the first storage area 45a of the storage area 45(1).

[0030] When the sub-control circuit 41(1) receives the first data unit of the first line from the main control circuit 7a, it stores data D1 to data D5 in the second storage area 45b (see FIG. 5(2)). Note that the free capacity of the second storage area 45b is larger than the data amount of the first data unit.

[0031] Since 0 is stored in the first storage area 45a, the sub-control circuit 41(1) stores the data D1 corresponding to itself. Hereinafter, the data of the k-th line stored is also referred to as data Lk (k = 1 to 9). That is, the sub-control circuit 41(1) stores data L1. Also, the sub-control circuit 41(1) rewrites the information stored in the first storage area 45a. That is, it rewrites from 0 to 1 (see FIG. 5(3)).

[0032] The sub-control circuit 41(1) reads out the print data that is the first data unit excluding the data L1, i.e., the data D2 to D5, which is the data corresponding to itself, from its second storage area 45b, transmits it to the downstream side, and deletes it from the second storage area 45b (see Fig. 5(4)). When the sub-control circuit 41(1) receives the second data unit of the first line from the main control circuit 7a, it stores the data D6 to D9 in the second storage area 45b (see Fig. 5(5)). Note that the free capacity of the second storage area 45b is larger than the data amount of the second data unit.

[0033] Since 1 is stored in the first storage area 45a of the sub-control circuit 41(1), the entire second data unit, i.e., the data D6 to D9, is transmitted to the downstream side and deleted from the second storage area 45b (see Fig. 5(6)).

[0034] Fig. 6 is a conceptual diagram showing the storage area 45 of the sub-control circuit 41 excluding the uppermost and lowermost sub-control circuits 41 when receiving the print data of the first line. Note that Fig. 6 shows the storage area 45(2) of the sub-control circuit 41(2) located one downstream from the uppermost sub-control circuit 41(1) as an example of the storage area 45 of the sub-control circuit 41 excluding the uppermost and lowermost sub-control circuits 41. As shown in Fig. 6(1), in the initial state, 0 is stored in the first storage area 45a of the storage area 45(2).

[0035] When the sub-control circuit 41(2) receives the first data unit of the first line from the sub-control circuit 41(1), it stores the data D2 to D5 in the second storage area 45b (see Fig. 6(2)). Note that the free capacity of the second storage area 45b is larger than the data amount of the first data unit.

[0036] Since 0 is stored in the first storage area 45a of the sub-control circuit 41(2), it stores the data D2 of the first line corresponding to itself, i.e., the data L1. Also, the sub-control circuit 41(1) rewrites the information stored in the first storage area 45a. That is, it rewrites from 0 to 1 (see Fig. 6(3)).

[0037] The sub-control circuit 41(2) reads out the print data D3 to D5, which are the print data excluding the data L1, that is, the print data excluding the data corresponding to itself, from its second storage area 45b, transmits it downstream, and deletes it from the second storage area 45b (see Fig. 6(4)). When the sub-control circuit 41(2) receives the second data unit of the first line from the sub-control circuit 41(1), it stores the data D6 to D9 in the second storage area 45b (see Fig. 6(5)). Note that the free capacity of the second storage area 45b is larger than the data amount of the second data unit.

[0038] Since 1 is stored in the first storage area 45a of the sub-control circuit 41(2), the entire second data unit, that is, the data D6 to D9, is transmitted downstream and deleted from the second storage area 45b (see Fig. 6(6)).

[0039] Similarly, the sub-control circuits 41(3) to 41(8) also store the print data corresponding to themselves and transmit the print data excluding the data corresponding to themselves downstream. Note that the sub-control circuit (5) stores the data D5 and does not transmit one data unit downstream, so the sub-control circuits (6) to (9) receive only the second data unit from the upstream side.

[0040] Fig. 7 is a conceptual diagram showing the storage area 45(9) of the most downstream sub-control circuit 41(9) when receiving the print data of the first line. As shown in Fig. 7(1), in the initial state, 0 is stored in the first storage area 45a of the storage area 45(9). When the sub-control circuit 41(9) receives the second data unit of the first line from the sub-control circuit 41(8), that is, when receiving the data D9, it stores the data D9 in the second storage area 45b (see Fig. 7(2)). Note that the free capacity of the second storage area 45b is larger than the data amount of the second data unit.

[0041] Since the sub-control circuit 41(9) has 0 stored in the first storage area 45a, it stores the data D9 on the first line corresponding to itself, that is, the data L1. Also, the sub-control circuit 41(9) rewrites the information stored in the first storage area 45a. That is, it rewrites from 0 to 1 (see Fig. 7(3)). The sub-control circuit 41(9) is the sub-control circuit 41 located at the most downstream. Therefore, it cannot transfer print data downstream from itself.

[0042] The sub-control circuit 41(9) rewrites the information stored in the first storage area 45a. That is, it rewrites from 1 to 0 (see Fig. 7(4)), and sends a notification indicating that it rewrites the information stored in the first storage area 45a to the upstream side. That is, it sends a notification indicating that it rewrites 1, which is the information stored in the first storage area 45a of each sub-control circuit 41(1) to 41(8), to 0. In other words, when the sub-control circuit 41 located at the most downstream receives the print data corresponding to itself, it sends a notification to the upstream side indicating that it rewrites 1, which is the information indicating the second transmission method, to 0, which is the information indicating the first transmission. Note that the sub-control circuit 41(9) may store 0 without rewriting the information stored in the first storage area 45a, store the data L1, and send a notification to the upstream side.

[0043] Each of the sub-control circuits 41(8) to 41(1) transfers the received notification to the upstream side and rewrites 1 stored in its own first storage area 45a to 0. The sub-control circuit 41(1) located most upstream among the plurality of sub-control circuits 41 sends the free capacity of its own second storage area 45b to the main control circuit 7a together with the notification.

[0044] When the main control circuit 7a receives a notification from the sub-control circuit 41(1), it sends the print data of the next line to the downstream side. When the main control circuit 7a receives a notification, each sub-control circuit 41 has already stored the print data for one line. That is, the reception of the notification in the main control circuit 7a indicates that the transmission of the print data for one line is completed, and after the main control circuit 7a completes the transmission of the print data for one line, it sends the print data of the next line to the downstream side.

[0045] When the free capacity of the second storage area 45b of the sub-control circuit 41(1) is less than a predetermined capacity, the main control circuit 7a changes the data amount of each data unit (the first data unit and the second data unit), that is, reduces the data amount, so as not to exceed the free capacity of the second storage area 45b, and transmits the print data of the next line to the downstream side. Examples of methods for reducing the data amount include a method of dividing data or a method of compressing data.

[0046] FIG. 8 is a conceptual diagram showing the storage area 45(1) of the uppermost upstream sub-control circuit 41(1) when receiving print data of the second line. After receiving the print data of the first line and before receiving the print data of the second line, the uppermost upstream sub-control circuit 41(1) stores 1 in the first storage area 45a and stores L1 in the second storage area 45b (see FIG. 8(1)). When the sub-control circuit 41(1) receives a notification from the sub-control circuit 41(2), that is, a notification indicating that the information stored in the first storage area 45a is to be rewritten, it rewrites 1 in the first storage area 45a to 0 (see FIG. 8(2)).

[0047] When the sub-control circuit 41(1) receives the first data unit of the second line from the main control circuit 7a, it stores data D1 to data D5 in the second storage area 45b (see FIG. 8(3)). Note that the free capacity of the second storage area 45b is larger than the data amount of the first data unit.

[0048] Since 0 is stored in the first storage area 45a, the sub-control circuit 41(1) stores the data D1 of the second line corresponding to itself, that is, data L2. The sub-control circuit 41(1) also rewrites the information stored in the first storage area 45a. That is, it rewrites from 0 to 1 (see FIG. 8(4)).

[0049] The sub-control circuit 41(1) transmits the print data from the data D2 to the data D5, which is the first data unit excluding the data L2, i.e., the print data excluding the data corresponding to itself, to the downstream side and deletes it from the second storage area 45b (see Fig. 8(5)). When the sub-control circuit 41(1) receives the second data unit on the second line, i.e., the data D6 to the data D9, from the main control circuit 7a, it stores the data D6 to the data D9 in the second storage area 45b (see Fig. 8(6)). Note that the free capacity of the second storage area 45b is larger than the data amount of the second data unit.

[0050] Since 1 is stored in the first storage area 45a in the sub-control circuit 41(1), the entire second data unit, i.e., the data D6 to the data D9, is transmitted to the downstream side and deleted from the second storage area 45b (see Fig. 8(7)).

[0051] In Fig. 5, the data D1 (data L1) is the print data corresponding to the sub-control circuit 41(1), and the data D2 to D9 are the print data excluding the data D1 corresponding to itself. The second storage area 45b is the same storage area that stores the data D1 and the data D2 to D9. That is, the sub-control circuit 41(1) has the same storage area that stores the data D1 and the print data excluding the data D1 (data D2 to D9). Similarly, the sub-control circuits 41(2) to 41(9) also have the same storage area (second storage area) that stores the print data corresponding to themselves and the print data excluding the print data corresponding to themselves.

[0052] The main control circuit 7a transmits the print data for all lines as described above. The sub-control circuits 41(2) to 41(9) store the print data for each line as described above. The sub-control circuits 41(1) to 41(9) execute printing at an appropriate timing for printing, that is, at the printing timing. For example, every time all the sub-control circuits 41(1) to 41(9) store the print data for three lines, the sub-control circuits 41(1) to 41(9) read out the print data corresponding to themselves from their second storage areas 45b, transmit it to the heads 42 corresponding to themselves, and execute printing. As described above, the sub-control circuits 41(1) to 41(8) read out the print data excluding the print data corresponding to themselves from their second storage areas 45b and transmit it to the downstream side.

[0053] For example, when the main control circuit 7a receives three notifications indicating that it rewrites 1 transmitted from the sub-control circuit 41(9) at the most downstream to 0, it determines that all the sub-control circuits 41(1) to 41(9) have stored the print data for three lines, and transmits a print execution command to all the sub-control circuits 41(1) to 41(9). The sub-control circuits 41(1) to 41(9) that have received the print execution command execute printing. The sub-control circuits 41(1) to 41(9) delete the print data for which printing has been executed, that is, the data Lk for which printing has been executed, from each second storage area 45b. Note that the printing timing is not limited to the case where all the sub-control circuits 41(1) to 41(9) store the print data for three lines, and may also be the case where all the sub-control circuits 41(1) to 41(9) store the print data for one line, two lines, or four or more lines.

[0054] FIG. 9 is a flowchart for explaining the data transmission process by the main control circuit 7a. The control unit 7b of the main control circuit 7a determines whether or not a print start signal has been received (S1). For example, when the user operates the print start switch, a print start signal is input to the main control circuit 7a. If the print start signal has not been received (S1: NO), the control unit 7b returns the process to step S1. When the print start signal is received (S1: YES), the control unit 7b generates data units for one line, for example, the first data unit and the second data unit (S2), and sequentially transmits each data unit (S3). The control unit 7b transmits the first data unit and then transmits the second data unit. In steps S2 and S3, after generating and transmitting the first data unit, the second data unit may be generated and transmitted.

[0055] The control unit 7b determines whether or not all the print data for all lines has been transmitted (S4). If it is determined that not all the print data for all lines has been transmitted (S4: NO), the control unit 7b determines whether or not it has received a notification indicating that the information stored in the first storage area 45a is rewritten from 1 to 0 and the free capacity of the second storage area 45b of the sub-control circuit 41(1) (S5). If it is determined that the notification and the free capacity have not been received (S5: NO), the control unit 7b returns the process to step S5.

[0056] If it is determined that the notification and the free capacity have been received (S5: YES), the control unit 7b determines whether or not the free capacity is equal to or greater than a predetermined capacity (S6). The predetermined capacity is, for example, a predetermined multiple of the data amount of the data unit. For example, it is p times the data amount of the data unit. p is a value greater than 1, for example, 1.5 or more. The data amount of the data unit is the data amount of the data unit transmitted in step S2, and when a plurality of data units are transmitted, it is the data amount of the largest data unit.

[0057] When it is determined that the free capacity is equal to or greater than a predetermined capacity (S6: YES), the control unit 7b returns the process to step S2. When it is determined that the free capacity is not equal to or greater than the predetermined capacity (S6: NO), that is, when it is determined that the free capacity is less than the predetermined capacity, the control unit 7b changes the data amount of the data unit so as to be smaller than the free capacity of the second storage area 45b of the sub-control circuit 41(1) (S7). For example, the control unit 7b determines the data amount of the data unit (the first data unit and the second data unit) based on the value obtained by dividing the free capacity by q. q is a value greater than 1, for example, 3 or more. q may be any value as long as the free capacity becomes equal to or greater than the predetermined capacity in step S6.

[0058] In step S3, when it is determined that the print data for all lines has been transmitted (S4: YES), the control unit 7b ends the process.

[0059] FIG. 10 is a flowchart for explaining the data transmission process by the control units 41a of the sub-control circuits 41(1) to 41(8) excluding the sub-control circuit 41(9) at the most downstream. The control unit 41a determines whether or not it has received the data unit for the k-th line from the upstream side (S11). When the data unit for the k-th line has not been received (S11: NO), the control unit 41a returns the process to step S11. When the data unit has been received (S11: YES), the control unit 41a determines whether or not 0 is stored in the first storage area 45a (S12).

[0060] When it is determined that 0 is stored in the first storage area 45a (S12: YES), the control unit 41a stores the data corresponding to itself in the k-th line, that is, data Lk (S13), and rewrites the data in the first storage area 45a from 0 to 1 (S14). The control unit 41a transmits the remaining data units excluding the data Lk to the downstream side (S15). The control unit 41a determines whether or not it has received a notification from the downstream side indicating that the data in the first storage area 45a is to be rewritten from 1 to 0 (S17).

[0061] When it is determined that no notification has been received (S17: NO), the control unit 41a returns the process to step S11. When it is determined that a notification has been received (S17: YES), the control unit 41a rewrites the data in the first storage area 45a from 1 to 0 (S18), and transmits a notification indicating that the data in the first storage area 45a is rewritten from 1 to 0 to the upstream side, or transmits a notification indicating that the data in the first storage area 45a is rewritten from 1 to 0 and the free capacity of the second storage area 45b in its own sub-control circuit 41 to the upstream side (S19). The control unit 41a of the most upstream sub-control circuit 41(1) transmits the notification and the free capacity to the upstream side, and the control units 41a of the sub-control circuits 41(2) to 41(8) excluding the most upstream sub-control circuit 41(1) transmit the notification to the upstream side. The control unit 41a returns the process to step S11.

[0062] In step S12, when it is determined that 0 is not stored in the first storage area 45a (S12: NO), that is, when it is determined that 1 is stored, the control unit 41a transmits the entire data unit to the downstream side without saving the data (S16), and proceeds to step S17.

[0063] FIG. 11 is a flowchart for explaining data transmission processing by the control unit 41a of the most downstream sub-control circuit 41(9). In the initial state, 0 is stored in the first storage area 45a of the sub-control circuit 41(9).

[0064] The control unit 41a determines whether it has received the data unit of the k-th line from the upstream side (S21). If it has not received the data unit of the k-th line (S21: NO), the control unit 41a returns the process to step S21. When it has received the data unit (S21: YES), the control unit 41a stores the data corresponding to itself in the k-th line, that is, data Lk (S22), and rewrites the data in the first storage area 45a from 0 to 1 (S23). The control unit 41a rewrites the data in the first storage area 45a from 1 to 0 (S24), sends a notification indicating that the data in the first storage area 45a is rewritten from 1 to 0 to the upstream side (S25), and returns the process to step S21. Note that the control unit 41a of the sub-control circuit 41(9) does not have to execute the processes of steps S23 and S24.

[0065] FIG. 12 is a flowchart for explaining the printing process by the control unit 7b of the main control circuit 7a. The control unit 7b determines whether it is the printing timing (S31). If it determines that it is not the printing timing (S31: NO), the control unit 7b returns the process to step S31. When it determines that it is the printing timing (S31: YES), the control unit 7b sends a print execution command to the sub-control circuit 41(1) (S32). The print execution command is transferred to the sub-control circuit 41(9) at the most downstream. The sub-control circuits 41(1) to 41(9) send the print data to the head 42 and execute printing. The sub-control circuits 41(1) to 41(9) delete the printed print data from each second storage area 45b.

[0066] The control unit 7b determines whether the printing has been completed (S33). For example, when it has received a notification indicating that the printing has been completed from the sub-control circuits 41(1) to 41(9) for all the print data received from the external device 9, or when a print stop signal is input from the print stop switch, it determines that the printing has been completed. When it determines that the printing has not been completed (S33: NO), the control unit 7b returns the process to step S31. When it determines that the printing has been completed (S33: YES), the control unit 7b ends the process.

[0067] In the printing apparatus 1 according to Embodiment 1, information indicating a method of transmitting print data is stored in the first storage area 45a of the sub-control circuit 41. When print data is received, the print data is transmitted downstream according to the transmission method indicated by the information. For example, when the information indicates a method of transmitting without storing the print data, when the sub-control circuit 41 receives print data from upstream, it transmits it downstream without storing it in its second storage area 45b, and can suppress a decrease in the efficiency of the print data transmission process. Further, since the sub-control circuit 41 transmits without storing the print data, the capacity of the main storage unit 41b can be reduced, and the cost of the components constituting the main storage unit 41b can be reduced.

[0068] Note that the main control circuit 7a may generate and transmit three or more data units in steps S2 and S3 (see FIG. 9). For example, the main control circuit 7a may generate and transmit a first data unit including data D1 to D3, a data unit including data D4 to D6 (hereinafter, the second data unit (1)), and a data unit including data D7 to D9 (hereinafter, the second data unit (2)). After generating and transmitting the first data unit, the main control circuit 7a may generate and transmit the second data unit, and after generating and transmitting the second data unit, generate and transmit the third data unit.

[0069] In this case, the second data unit (1) is a data unit including the most upstream data D4 of the remaining print data from the remaining print data obtained by excluding the generated data unit (the first data unit) from one line of print data. Data D4 corresponds to the s-th data. The second data unit (2) is a data unit including the most upstream data D7 of the remaining print data from the remaining print data obtained by excluding the generated data units (the first data unit and the second data unit (1)) from one line of print data. Data D7 corresponds to the s-th data.

[0070] That is, when generating three or more data units in step S2 (see FIG. 9), the main control circuit 7a, after the generation process of the first data unit, from the print data of one line, from the remaining print data excluding the generated data units, repeatedly generates a data unit including the most upstream data of the remaining print data, that is, the second data unit. When each sub-control circuit 41 receives a data unit such as the first data unit, the second data unit, or the third data unit, as described above, when the information stored in the first storage area 45a is 0, it stores the data corresponding to itself in the second storage area 45b, reads out the data unit excluding the data corresponding to itself from its own second storage area 45b, transmits it to the downstream side, and deletes it from the second storage area 45b. Also, the information stored in the first storage area 45a is rewritten from 0 to 1. On the other hand, when receiving a data unit, if the information stored in the first storage area 45a is 1, each sub-control circuit 41 transmits the entire received data unit to the downstream side and deletes the data unit from the second storage area 45b.

[0071] In addition, when the free capacity of the second storage area 45b of the sub-control circuit 41(1) is equal to or more than a predetermined capacity, the main control circuit 7a changes the data amount of each data unit (the first data unit and the second data unit) so as not to exceed the free capacity of the second storage area 45b, that is, increases the data amount, and transmits the print data of the next line to the downstream side. Examples of the method of increasing the data amount include a method of not dividing the data or a method of reducing the number of divisions of the data.

[0072] (Embodiment 2) The following will be described based on the drawings showing the printing apparatus according to Embodiment 2 of the present invention. Among the configurations of the printing apparatus 1 according to Embodiment 2, the same configurations as those in Embodiment 1 are denoted by the same reference numerals, and detailed descriptions thereof are omitted. In Embodiment 1, the control unit 7b determines whether or not it has received the free capacity of the second storage area 45b of the sub-control circuit 41(1), but in Embodiment 2, the sub-control circuit 41(1) is inquired about the free capacity of the second storage area 45b. FIG. 13 is a flowchart for explaining the data transmission process by the main control circuit 7a. Steps S41 to S44, S48, and S49 in FIG. 13 are the same processes as steps S1 to S4, S6, and S7 in FIG. 9, and thus detailed descriptions thereof are omitted. Here, the processes of steps S45 to S47 will be mainly described.

[0073] In step S44, when it is determined that the print data for all lines has not been transmitted (S44: NO), the control unit 7b determines whether or not it has received a notification indicating that the information stored in the first storage area 45a is rewritten from 1 to 0 (S45). When it is determined that the notification has not been received (S45: NO), the control unit 7b returns the process to step S45.

[0074] When it is determined that the notification has been received (S45: YES), the control unit 7b inquires the uppermost sub-control circuit 41(1) about the free capacity of the second storage area 45b (S46). The control unit 7b determines whether or not it has received the free capacity of the sub-control circuit 41(1) (S47). When it is determined that the free capacity of the sub-control circuit 41(1) has not been received (S47: NO), the control unit 7b returns the process to step S47. When it is determined that the free capacity of the sub-control circuit 41(1) has been received (S47: YES), the control unit 7b proceeds to step S48.

[0075] FIG. 14 is a flowchart for explaining the data transmission process by the control units 41a of the sub-control circuits 41(1) to 41(8) excluding the lowermost sub-control circuit 41(9). Steps S51 to S58 in FIG. 14 are the same processes as steps S11 to S18 in FIG. 10, and thus detailed descriptions thereof are omitted. Here, the processes of steps S59 to S61 will be mainly described.

[0076] The control unit 41a transmits a notification indicating that the data in the first storage area 45a is rewritten from 1 to 0 to the upstream side (S59). The control unit 41a determines whether it has received an inquiry about the free capacity of the second storage area 45b from the main control circuit 7a (S60). If it is determined that the inquiry has not been received (S60: NO), the control unit 41a returns the process to step S51. Note that the sub-control circuits 41(2) to 41(8) do not receive an inquiry from the main control circuit 7a.

[0077] If it is determined that the inquiry has been received (S60: YES), the control unit 41a transmits the free capacity to the main control circuit 7a (S61), and returns the process to step S51. When the sub-control circuit 41(1) receives an inquiry from the main control circuit 7a, it transmits the free capacity to the main control circuit 7a.

[0078] (Embodiment 3) Hereinafter, the present invention will be described based on the drawings showing the printing apparatus according to Embodiment 3. Among the configurations of the printing apparatus 1 according to Embodiment 3, the same configurations as those in Embodiment 1 or 2 are denoted by the same reference numerals, and detailed descriptions thereof are omitted. In Embodiment 1, the control unit 7b determines whether it has received the free capacity of the second storage area 45b of the sub-control circuit 41(1), but in Embodiment 3, it determines whether it has received a request to change the data amount of the data unit from the sub-control circuit 41(1). FIG. 15 is a flowchart for explaining the data transmission process by the main control circuit 7a. Steps S71 to S75 in FIG. 15 are the same processes as steps S41 to S45 in FIG. 13, and thus detailed descriptions thereof are omitted. Here, the processes of steps S76 and S77 will be mainly described.

[0079] When the control unit 7b receives a notification indicating that the information stored in the first storage area 45a is rewritten from 1 to 0 (S75: YES), it determines whether or not it has received a request to change the data amount of the data unit from the sub-control circuit 41(1) (S76). If it determines that no change request has been received (S76: NO), the control unit 7b returns the process to step S72. If it determines that a change request has been received (S76: YES), the control unit 7b changes the data amount of the data unit (S77) and returns the process to step S72.

[0080] As will be described later, when the free capacity of the second storage area 45b in any of the sub-control circuits 41 becomes equal to or smaller than the data amount of the data unit, that sub-control circuit 41 transmits a change request to the upstream side. The change request is transferred up to the main control circuit 7a. The control unit 7b changes the data amount of the data unit so that it becomes sufficiently smaller than the free capacity of the second storage area 45b. For example, when the main control circuit 7a receives a change request after transmitting the first data unit including data D1 to D5, in steps S72 and S73, the main control circuit 7a generates and transmits the first data unit including data D6 to D7 and the second data unit including data D8 to D9. Note that the main control circuit 7a may generate and transmit three or more data units.

[0081] FIG. 16 is a flowchart for explaining the data transmission process by the control units 41a of the sub-control circuits 41(1) to 41(8) excluding the most downstream sub-control circuit 41(9). Steps S81 to S89 in FIG. 16 are the same processes as steps S51 to S59 in FIG. 14, so detailed description thereof is omitted. Here, mainly the processes of steps S90 and S91 will be described.

[0082] The control unit 41a determines whether or not the free capacity of the second storage area 45b in its own sub-control circuit 41 is equal to or less than a predetermined capacity (S90). The predetermined capacity is, for example, a predetermined multiple of the data amount of the data unit. For example, it is r times the data amount of the data unit. r is a value of 1 or more, for example, 1.05 or more. If it is determined that the free capacity is not equal to or less than the predetermined capacity (S90: NO), the control unit 41a returns the process to step S81. If it is determined that the free capacity is equal to or less than the predetermined capacity (S90: YES), the control unit 41a transmits a change request for the data amount of the data unit to the upstream side (S91), and returns the process to step S81. When each sub-control circuit 41 receives a change request from the downstream side, it transfers the change request to the main control circuit 7a.

[0083] (Embodiment 4) Hereinafter, the present invention will be described based on the drawings showing the printing apparatus according to Embodiment 4. Among the configurations of the printing apparatus 1 according to Embodiment 4, the same configurations as those in Embodiments 1 to 3 are denoted by the same reference numerals, and detailed descriptions thereof are omitted. In Embodiment 1, the control unit 7b determines whether or not it has received the free capacity of the second storage area 45b of the sub-control circuit 41(1). In Embodiment 4, however, the free capacity in the second storage area 45b of each sub-control circuit 41 is calculated, and it is determined whether or not the minimum free capacity is equal to or less than a predetermined capacity. FIG. 17 is a flowchart for explaining the data transmission process by the main control circuit 7a. Steps S101 to S105 in FIG. 17 are the same processes as steps S41 to S45 in FIG. 13, and thus detailed descriptions thereof are omitted. Here, the processes of steps S106 to S108 will be mainly described.

[0084] When the control unit 7b receives a notification indicating that the information stored in the first storage area 45a is to be rewritten from 1 to 0 (S105: YES), it calculates the free capacity in the second storage area 45b of each sub-control circuit 41 (S106). The storage capacity of the second storage area 45b of each sub-control circuit 41 is stored in advance in the auxiliary storage unit 7d. The control unit 7b calculates the free capacity in the second storage area 45b of each sub-control circuit 41 based on the data amount of the print data transmitted downstream from the main control circuit 7a and the data amount of the print data that has been printed by the print execution command and deleted from the second storage area 45b of each sub-control circuit 41.

[0085] The control unit 7b determines whether the minimum free capacity among the free capacities in the second storage area 45b of each sub-control circuit 41 is less than or equal to a predetermined capacity (S107). The predetermined capacity is, for example, a predetermined multiple of the data amount of a data unit. For example, it is t times the data amount of a data unit. t is a value of 1 or more, for example, 1.5 or more. If it is determined that the minimum free capacity is not less than or equal to the predetermined capacity (S107: NO), the control unit 7b returns the process to step S102. If it is determined that the minimum free capacity is less than or equal to the predetermined capacity (S107: YES), the control unit 7b changes the data amount of the data unit (S108) and returns the process to step S102.

[0086] The computer program can be deployed to be executed on a single computer, or placed at one site, or distributed across multiple sites and executed on multiple computers interconnected by a communication network.

[0087] The main control circuit 7a may include a plurality of control units 7b. The main control circuit 7a may perform distributed processing of a single process using a plurality of control units 7b, or may perform parallel processing of a plurality of processes using a plurality of control units 7b. The sub-control circuit 41 may include a plurality of control units 41a. The sub-control circuit 41 may perform distributed processing of a single process using a plurality of control units 41a, or may perform parallel processing of a plurality of processes using a plurality of control units 41a.

[0088] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present invention is intended to include all modifications within the scope of the claims and the scope equivalent to the claims. The matters described in each embodiment can be combined with each other. Further, the independent claims and dependent claims described in the claims can be combined with each other in all possible combinations regardless of the citation form. Furthermore, although the claims use a form (multi-claim form) of describing a claim that cites two or more other claims, it is not limited thereto. It may be described using a form of describing a multi-claim (multi-multi-claim) that cites at least one multi-claim.

Explanation of Signs

[0089] 1 Printing device 7 Control device 7a Main control circuit 7b Control unit 7c Main storage unit 7d Auxiliary storage unit 41 Sub-control circuit 41a Control unit 41b Main storage unit 41c Auxiliary storage unit 42 Head 45 Storage area 45a First storage area 45b Second storage area

Claims

1. A main control circuit, a plurality of sub-control circuits connected in series with each other and transmitting print data transmitted by the main control circuit from upstream to downstream, and comprising: each sub-control circuit stores information indicating a transmission method of the print data, and when receiving the print data, transmits the print data downstream according to the transmission method indicated by the information. A printing apparatus.

2. The plurality of sub-control circuits include a first sub-control circuit which is the uppermost-stream sub-control circuit to an nth sub-control circuit which is the lowermost-stream sub-control circuit (n is a natural number of 2 or more), the print data includes first data to nth data corresponding to the first sub-control circuit to the nth sub-control circuit, the information stored in the kth sub-control circuit (k is a natural number from 1 to n - 1) indicates a first transmission method of storing the kth data included in the received print data and transmitting the print data excluding the kth data to the downstream side, or a second transmission method of transmitting the entire received print data to the downstream side, the main control circuit executes a transmission process of transmitting the first data to the nth data from upstream data to the first sub-control circuit, in an initial state, the information stored in the kth sub-control circuit indicates the first transmission method, when the kth sub-control circuit receives the print data, after storing the kth data, the kth sub-control circuit transmits the print data excluding the kth data to the downstream side and rewrites the information to information indicating the second transmission method. The printing apparatus according to Claim 1.

3. When the information stored in the kth sub-control circuit is the second transmission method and the kth sub-control circuit receives the print data, the kth sub-control circuit transmits the entire received print data to the downstream side without storing the print data. The printing apparatus according to Claim 2.

4. The print data includes a plurality of data units, the main control circuit executes a first generation process of generating a first data unit including the first data from the print data, a second generation process of generating a second data unit including the s-th data which is the uppermost-stream data of the remaining print data from the remaining print data which is the print data excluding the generated data units (s is a natural number of 2 or more), a first transmission process of transmitting the generated first data unit to the first sub-control circuit, and a second transmission process of transmitting the generated second data unit to the first sub-control circuit. and executes. In the transmission process, after executing the first transmission process, the main control circuit executes the second transmission process. The printing apparatus according to claim 2 or 3.

5. After executing the first generation process, the main control circuit repeats the second generation process. The printing apparatus according to claim 4.

6. The first sub-control circuit includes a storage unit. Based on the free capacity in the storage unit, the main control circuit determines the data amounts of the first data unit and the second data unit. The printing apparatus according to claim 4.

7. The main control circuit acquires the free capacity of the storage unit from the first sub-control circuit. The printing apparatus according to claim 6.

8. The first sub-control circuit includes a storage unit. Based on the capacity of the storage unit and the data amount transmitted to the first sub-control circuit, the main control circuit changes the data amounts of the first data unit and the second data unit. The printing apparatus according to claim 4.

9. Comprising a plurality of heads corresponding to the plurality of sub-control circuits. The k-th sub-control circuit has the same storage area for storing the k-th data and the print data excluding the k-th data. The k-th sub-control circuit reads out the k-th data from the storage area, transmits it to the head corresponding to itself, reads out the print data excluding the k-th data from the storage area, and transmits it downstream. The printing apparatus according to claim 2 or 3.

10. In a printing method executed by a printing apparatus including a main control circuit and a plurality of sub-control circuits connected in series for transmitting print data transmitted by the main control circuit from upstream to downstream. Each sub-control circuit stores information indicating the transmission method of the print data, and when receiving the print data, transmits the print data downstream according to the transmission method indicated by the information. Printing method.

11. In a computer program executed by a printing apparatus including a main control circuit and a plurality of sub-control circuits connected in series for transmitting print data transmitted by the main control circuit from upstream to downstream. In each sub-control circuit stores information indicating the transmission method of the print data, and when receiving the print data, transmits the print data downstream according to the transmission method indicated by the information. A computer program for executing the process.

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