JP3624046B2 - Image forming apparatus, video controller, option controller, and control method in option sheet feeding apparatus - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an image forming apparatus that includes a video controller that develops a code signal for printing received from a host computer into an image signal, and an engine controller that controls a printer engine, to which an optional sheet feeding device can be connected. The video controller relates to a method of controlling the printer engine and the optional paper feeder.
[0002]
[Prior art]
Conventionally, when a paper processing device such as a paper discharge unit such as a paper feed deck or a finisher is connected to the image forming apparatus, the image forming control device in the image forming apparatus performs all paper transport control in an integrated manner. .
[0003]
[Problems to be solved by the invention]
However, in the above conventional example, when the image forming apparatus is changed or the option unit is changed, it cannot be used in combination. This is because of differences in the paper transport speed, paper transport path (path), option unit paper transport speed, paper transport path, option unit paper processing time, such as finisher stapling, It depends on differences in processing time for folding paper and sorting time for sorters.
[0004]
It is not impossible to program all of these conceivable information in the CPU memory of the image forming control apparatus. However, since the optional unit is not always installed, the image forming control apparatus bears an extra load. As a result, the cost of the image forming control apparatus is increased. Furthermore, there are many possible variations of the optional unit, but it is very difficult to cover all of them because the memory capacity increases. Although it is conceivable to provide the image information control device with control of the option unit, the image information control device must process image information to be printed at high speed. Has the disadvantage of slowing down the time.
[0005]
Accordingly, a first object of the present invention is to reduce the paper management burden of the CPU of the engine controller (image formation control device) and video controller (image information control device), and speed up the printing operation inherent in the image formation device. It is to provide a control method that can be achieved.
[0006]
The second object of the present invention is to minimize the change of the engine controller and the video controller when a paper processing device such as a paper feeding device or a paper discharging device is optionally connected to the image forming device, and a combination thereof. It is in providing the control method which can choose freely.
[0007]
A third object of the present invention is to provide a dedicated CPU for the option controller to manage the movement of paper in the image forming apparatus and the movement of paper in the option unit. Provides a control method that allows the option controller to determine the optimal print timing according to the paper transport speed, paper transport path length, paper length, and paper mode in the device and optional unit, and achieve the fastest throughput. There is to do.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises a video controller that develops a code signal for printing received from a host computer into an image signal, and an engine controller that controls a printer engine. In a connectable image forming apparatus, the video controller controls the printer engine and the optional paper feeding device, and when the paper is fed from a paper feeding cassette of the main body of the image forming apparatus, printing is performed on the engine controller. Instructing the engine controller to cause the engine controller to feed paper from the paper feed cassette of the image forming apparatus main body and start printing. When feeding from the optional paper feeder, the engine controller performs printing. Prior to instructing the start, the engine controller By specifying to feed the paper from the optional paper feeding device without going through a roller, the paper is fed from the optional paper feeding device,
Waiting for the notification that printing can be started, which is output in response to detection of the fed paper by the paper sensor connected to the controller of the optional paper feeder, prints to the engine controller The start is instructed to cause the engine controller to start printing.
[0013]
【Example】
Next, embodiments of the present invention will be described with reference to the drawings.
[0014]
(Example 1)
FIG. 1 is a schematic cross-sectional view showing the configuration of the entire image forming apparatus. In FIG. 1, 1 is an image forming apparatus main body, 2 is an optional paper feed deck, and 3 is an optional finisher having a stapler. In the image forming apparatus main body 1, a paper feed cassette 4, a paper feed roller 5, a registration roller 6, a photosensitive drum 7, and a fixing device 8 are arranged on a paper transport path 8. In the inside of the paper feed deck 2, paper is stacked on a lifter, and the paper is sent out by a paper feed roller 9. Inside the finisher 3, a paper reversing unit 10 and a stapler 11 are provided, and three paper discharge trays 12 are movably arranged so that paper can be placed while the trays are moving. It has become.
[0015]
FIG. 3 is a block diagram of the main control circuit. In FIG. 3, reference numeral 15 denotes an engine controller (image formation control device) that performs control of the image forming process of the image forming apparatus 1 and paper feed control of the paper feed cassette 4. Reference numeral 16 denotes a video controller (image information control device) which develops a code signal for printing received from a host computer into an image signal. Reference numeral 17 denotes an optional controller (paper transport control device) that controls the paper feed deck 2 and the finisher 3 in an integrated manner. A paper feed deck controller 18 controls the paper feed deck 2. Reference numeral 19 denotes a finisher controller that controls the finisher 3.
[0016]
The video controller 16 is connected to the option controller 17 by a serial option controller interface. In addition, the paper feed deck controller 18 and the finisher controller 19 are connected to the option controller 17 by an serially connected option interface of serial communication.
[0017]
FIG. 2 is a circuit diagram of the option controller 17. The main communication lines with the video controller 16 are / CLK, / TX, / RX, / STROBE, and / CKEN. / CLK is a serial communication clock line, / TX is a transmission data line output from the video controller 16, / RX is a reception data line output from the option controller 17, and / STROBE is a communication strobe line. When this signal is active, a serial signal is transmitted. / CKEN is a clock enable signal. When this signal is active, the option controller 17 is informed that the video controller 16 is ready to receive a clock. / Indicates that the signal is low active.
[0018]
Next, signals to be taken into the option controller 17 in the video interface will be described.
/ PRNT, / VSYNC signal:
The above two signals are printing control signals that the video controller 16 originally outputs to the engine controller 15. When the option controller 17 is used, the above two signals are branched in hardware in the video controller 16 and output to both the engine controller 15 and the option controller 17. Among them, / PRNT is a print command to the main body 1 and instructs the start of the print operation, and instructs the start of paper feed when paper is fed from the cassette 4. The / VSYNC signal is a paper start instruction signal for waiting for the registration roller 6.
/ PDLV, / SPCHG, / PFED signals:
The above three signals are signals output from the engine controller 15. This is a signal for notifying the discharge timing from the engine body (image forming apparatus body) 1. When the option controller 17 is used, it passes through the video controller 16 and is output to the option controller 17. The option controller 17 uses the above three signals to control paper conveyance between the engine main body 1 and paper feed options (paper feed deck controller and finisher controller) 18 and 19.
[0019]
Next, the inside of the option controller 17 will be described. A central processing unit CPU 30 includes a RAM 32, a ROM, an I / O port, and a serial port 33. Note that RAM and ROM can be added outside the CPU. 31 is a buffer circuit for serial communication with the controllers 18 and 19 of the option unit. Reference numeral 20 denotes a buffer circuit for serial communication with the video controller 16. Reference numeral 21 denotes a reception buffer for taking in five of the signals in the video interface between the engine controller 15 and the video controller 16 into the option controller 17. The communication mode between the video controller 16 and the option controller 17 is performed by a system in which the RAM 32 in the CPU 30 is a shared memory. That is, information to be communicated with each other is written in the RAM at a specified address and read out. Therefore, the TX signal from the video controller 16 attaches a 2-byte address designation signal immediately before sending 1-byte data.
[0020]
Such an interface sharing a RAM has a collision problem in which two CPUs simultaneously access the same address. As a means for solving this problem, a method having a dual port RAM having an arbitration function is conceivable. However, since the dual port RAM is expensive, in the present invention, a RAM is accessed under the control of the CPU 30 using a serial port built into the CPU 30.
[0021]
The procedure is as follows. When 8-bit data is transmitted from the video controller 16 to the serial port 33, the serial port 33 interrupts the CPU 30. Then, the CPU 30 takes in the contents of the serial port 33. The first two bytes of the TX data from the video controller 16 are the address of the RAM 32 and a read / write instruction. If it is a write instruction, the third byte is written to the designated address of the RAM 32, and if it is a read instruction, the contents of the RAM 32 of the designated address are set in the serial port, and the video controller 16 is connected via the RX line with the clock of the third byte. Send data to. The CPU 30 analyzes the data (command) from the video controller 16 written to the designated address of the RAM 32, starts the next operation, and writes the status to be sent to the video controller 16 to the designated address for status. Since the CPU 30 manages the RAM 32, the problem of simultaneous access to the two CPUs does not occur.
[0022]
FIG. 4 is a timing chart showing communication timing and data arrangement between the video controller 16 and the option controller 17. Details of timing and data are as follows.
(1) The data is LSB first.
(2) The parity is odd parity (indicated by P in the drawing).
(3) A0 to A10 (vertical writing in the drawing) indicate addresses of the shared memory. WD0 to WD7 (vertical writing in the drawing) indicate write data. RD0 to RD7 (vertical writing in the drawing) indicate read data from the shared memory.
(4) R / W (vertical writing in the drawing) indicates writing when 1 (Low), and reading when 0 (High).
(5) When PERR-ADL (vertical writing in the drawing) is 1 (Low), it indicates that a parity error has occurred in the received address information.
(6) WOK and ROK are set to 1 (Low) when the option controller succeeds in writing and reading data.
(7) UK (vertical writing in the drawing) indicates an indefinite value.
[0023]
Next, paper conveyance control will be described. FIG. 5 shows the dimensions from the paper feed unit to the photosensitive drum. FIG. 6 is a timing chart regarding paper feeding. This will be described below with reference to FIGS.
[0024]
When code data to be printed is sent from the host computer to the video controller 16, the video controller 16 issues a print command PRNT signal to the engine controller 15. When the PRNT signal becomes true (true), the engine controller 15 starts paper feeding and initializes the photosensitive drum 7. If the paper feed cassette 4 is designated as the paper feed source, the paper feed roller 5 rotates and feeds the paper.
[0025]
The paper advances along the conveyance path and reaches the registration roller 6. The moving distance of the leading edge of the paper at this time is L. When the transport speed is S, the time t ₁ until reaching the registration roller 6 is
t ₁ = L / S
It becomes.
Here, after the paper reaches the registration roller 6, a loop is formed on the paper so that the paper is surely brought into contact with the registration roller 6 and the leading edge of the paper is aligned. The movement amount for this purpose is called a loop amount, and its length is P. When the time from receiving the PRNT signal to the formation of the loop is finished and _{t 2,} a t 2 = (L + P) / S.
[0026]
When the loop formation is completed, the engine controller 15 sets the / VSREQ signal to true. The / VSREQ signal is one of video interface signals sent from the engine controller 15 to the video controller 16. When the / VSREQ signal becomes true, the paper conveyance is temporarily stopped.
[0027]
Next, when the video controller 16 detects the true of the / VSREQ signal, the video controller 16 sets the / VSYNC signal to true. As a result, the engine controller 15 activates the registration roller 6. When the length of the paper is A, the time t ₃ when the paper passes the registration roller 6 is
t ₃ = A / S
It becomes.
[0028]
Furthermore, in order to feed the next paper, it is necessary to provide a distance Q between the previous paper and the paper. In this case, the time t ₄ from the leading end of the / VSYNC signal to the next paper feed timing is t ₄ = (t ₃ + Q / S) −t ₂
It becomes.
[0029]
Next, consider sheet feeding from the sheet feeding deck 2. In the case of paper feed from the paper feed deck, the length from the registration roller 6 of the main body 1 to the paper feed start position is M + N (where N is a load on the paper feed deck 2 as can be seen from FIG. 5). It is the length from the leading edge of the printed paper to the sensor 23). The paper sensor 23 is connected to the paper feed deck controller 18. The length M + N is sufficiently longer than the length B + Q of the paper set on the paper feed deck. Therefore, if the first sheet is fed to the registration roller 6 and the next sheet is fed after the first sheet is fed by the registration roller, the gap between the sheets becomes longer than the minimum necessary gap Q. End up. Therefore, the sensor 23 is provided, and the paper is sent to the position of the sensor 23 when paper feeding from the paper feeding deck is decided.
[0030]
When it is decided to feed paper from the paper feed deck 2, the video controller 16 writes the designation of the paper feed deck in the job table in the shared memory of the option controller 17. The option controller 17 instructs the sheet feeding deck 2 to start feeding from the designation. When it is detected that the leading edge of the paper has reached the sensor 23, the paper feed deck controller 18 temporarily stops paper conveyance and notifies the option controller 17 of the arrival of the paper.
[0031]
As shown in FIG. 7, the time so far is t ₅ ,
t ₅ = N / S
It becomes. The time t _5, the paper fed by the paper feed roller 9 whether reaches the sensor 23 at a predetermined time, i.e., is also used for detection of the jam.
[0032]
The option controller 17 immediately informs the video controller 16 that printing can be started. This is notified by writing in the job table of the paper feed deck controller 18.
[0033]
The video controller 16 sets the / PRNT signal to true and instructs the start of printing. The option controller 17 detects this, restarts the paper feed deck, and restarts the paper.
[0034]
The time t ₆ from when the paper is conveyed from the sensor 23 until the registration roller 6 forms a loop is t ₆ = (M + P) / S
It becomes.
[0035]
The time t ₇ from when the / VSYNC signal becomes true and the registration roller 6 starts to move until the next / PRNT becomes true is t ₇ = (B + Q) / S−t ₆
It becomes. Note that the time t ₈ from when / VSYNC becomes true to the paper feed deck designation command for the next paper to be fed is positive in FIG. 7, but negative when N is long or B is short. Sometimes. That is, it may be necessary to start feeding from the next paper feed deck before setting / VSYNC of the previous paper to true. Here, the time from t ₁ t _8, is unique to the main body and the sheet feed deck, of which, t ₄ and t ₇ are those dependent by the paper size.
[0036]
The time t _{1 to} t ₄ related to the cassette feeding of the main body is recorded in the ROM of the CPU of the engine controller 15, and the time t _{5 to} t ₈ related to the paper feeding deck is recorded in the ROM of the CPU of the paper feeding deck controller 18. The value recorded in the ROM of the CPU of the paper feed deck controller 18 is read out and used by the option controller 17.
[0037]
When the combination of the main body 1 and the sheet feeding deck 2 is changed, there is a case where time t ₅ ~t ₈ changes. This can occur when there are two types of main bodies and the paper transport speeds are different, the paper feed deck has a speed switching function, or there are two or more types.
[0038]
Therefore, an identification number (ID number) is assigned to the main body and the paper feed deck, each ID number is stored in the engine controller 15 and the paper feed deck controller of the main body 1, and the option controller calls it to correspond to each ID number. record the option controller ROM from t ₅ the value of t ₈ by paper size, using take it out.
[0039]
Next, the paper discharge processing time will be described. A problem in stapling with the finisher is the staple driving time of the stapler 11. When stapling 10 sheets of paper together, the 10 sheets of paper are stored at the stapler position, then stapled, and ejected to the tray when the staples are finished. We call this time the paper discharge processing time t _11. This operation only needs to be brought into ends at time t ₁₀ the paper distance Q / conveying speed S, but (to over) exceeds the t ₁₀ in practice. Further, the time of paper discharge processing time t ₁₁ -t ₁₀ will be referred to as paper discharge processing overtime t ₁₂ .
[0040]
t ₁₂ must delay the time to put this much extra / PRNT signal to the print start time. The value of t ₁₂ is may be recorded in the ROM of the CPU of the finisher controller 19, option controller uses a call to its value. For example, just when the discharge process time is required, CPU option controller 17 informs the video controller 16 to add the _{t 12} to the time _{t 4} when 6, video controller 16 / PRNT signal Delays sending.
[0041]
(Example 2)
In the first embodiment, each necessary timing value is recorded in the ROM of the option controller 16 or is recorded in the ROM of the controller of the option unit, which is called and used by the option controller. By the way, as the types of main bodies and options increase, the required timing value also increases. Since the time of / VSYNC, / PRNT and the like vary depending on the paper size, the time increases by the ratio of model × paper size, which imposes the ROM capacity.
[0042]
Therefore, there is a method in which the conveyance speed and the conveyance path length are called from the main body or the option unit and the necessary timing is calculated by the option controller 17. Since the paper size value is standardized, if the option controller 17 receives only the paper size code, the numerical value of the paper length for each code can be extracted from the ROM and used.
[0043]
(Example 3)
In the first embodiment, the timing t ₄ or t ₇ of the print command is notified by writing to the shared memory of the option controller when the option controller counts the time and it is time to issue the print command. . The advantage in this case is that the video controller 16 only needs to monitor a specific address of the shared memory. However, a disadvantage is that if the monitoring period is vacant, it may be delayed from the required timing. Therefore, it is determined as a solution, the time value of _{t 4} and _{t 7} from the option controller informs the video controller 16, video controller 16 counts the time from the output by / VSYNC yourself, the output timing of the / PRNT There is a way. The advantage of this method is that the output timing of / PRNT can be output accurately.
[0044]
【The invention's effect】
The first effect is that the CPU of the option controller has the CPU load of the image forming control device and the image information control device, so that the original printing operation of the image forming device can be speeded up.
[0045]
As a second effect, since the option controller has control related to the option controller, there is almost no part of the CPU of the image forming control device or the image information control device. For this reason, even if the combination of the main body and the option is changed, there is almost no change in the image forming control device and the image information control device, and it is only necessary to provide the option controller with the necessary transport speed and paper transport path information. As a result, the combination of the main body and the option unit can be freely changed.
[0046]
As a third effect, since the option controller determines the optimum sheet conveyance timing for the main body and the option unit and thereby performs sheet conveyance control, it is possible to obtain the fastest throughput as the image forming apparatus. is there.
[Brief description of the drawings]
FIG. 1 is a schematic side view showing an overall configuration of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is a circuit diagram centering on a paper transport control device;
FIG. 3 is a block diagram of a main control circuit.
FIG. 4 is a communication timing diagram between the image information control apparatus and the sheet conveyance control apparatus.
FIG. 5 is a dimensional diagram from a paper feeding unit to a photosensitive drum.
FIG. 6 is a control timing chart in the case of using a main body paper feed cassette.
FIG. 7 is a control timing chart when a paper feed deck is used.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 2 Optional paper feed deck 3 Optional finisher 4 Paper feed cassette 5 Paper feed roller 6 of paper cassette 6 Registration roller 7 Photosensitive drum 9 Paper feed roller 10 of paper feed deck Finisher 11 Stapler 15 Image formation control device (Engine controller)
16 Image information control device (video controller)
17 Paper transport control device (optional controller)
18 Feed deck controller 19 Finisher controller 30 Optional controller CPU
32 Dunram access memory

Claims (5)

A video controller to expand the code signal for printing received from the host computer to an image signal, and a engine controller for controlling the printer engine, Oite the optional sheet feeder to the image forming apparatus connectable, the video A method in which a controller controls the printer engine and the optional paper feeder ,
When feeding from the paper cassette of the image forming device
Instructing the engine controller to start printing causes the engine controller to feed paper from the paper feed cassette of the image forming apparatus main body and start printing,
When feeding from the optional paper feeder,
Prior to instructing the engine controller to start printing, the paper is fed from the optional paper feeding device by specifying the paper feeding from the optional paper feeding device without going through the engine controller. Let paper
Waiting for the notification that printing can be started, which is output in response to detection of the fed paper by the paper sensor connected to the controller of the optional paper feeder, prints to the engine controller A control method in an image forming apparatus, characterized by instructing start and causing the engine controller to start printing . The control method according to claim 1, wherein the optional paper feeder temporarily stops paper conveyance in response to detection of paper by the paper sensor. The method of claim 2, wherein said sheet transport by the optional sheet feeder in response to a print start instruction from the video controller, characterized in Rukoto is restarted. A finisher can be connected to the image forming apparatus, and when stapling is performed by the finisher, an instruction to start printing is delayed so as to secure a time required for stapling. The control method in any one. 5. The control method according to claim 1, wherein the exchange between the video controller and the optional paper feeder is performed via an optional controller.

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