JPH0133351B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a printing paper cutting method, more specifically, a printer and a paper post-processing machine are connected via an interface, and a paper cut command (CUT/ This relates to a printing paper cutting method that detects the cut point of the paper and cuts it based on CMD).

When printing output, a printer (NIP) and paper post-processing machine (BTS) are used in a printer that controls printing on a page-by-page basis of continuous folding paper, such as an electrophotographic laser printer.
A paper buffer is provided between the two to absorb the speed difference between the two.

A paper cut command is normally issued from the NIP side when it detects that a series of printing of the same type has finished.
Based on the above cut command, the paper is cut by the blade on the BTS side. Conventionally, as a means of detecting the cutting position of the paper, a mark is printed on a part of the paper and this mark is read by the BTS. is proposed.

However, it is actually very difficult to read the marks reliably, and on the other hand, it is not preferable in terms of form preparation to provide a writing area on the printing paper exclusively for the marks.

The present invention has been made in consideration of the above points, and its purpose is to provide a print that is excellent in practical use and can issue a paper cut command without adopting the marking method proposed in the past. This paper attempts to provide a method for cutting paper.

The present invention connects a printer and a paper post-processing device via a paper buffer, and detects the cut point of paper and cuts the paper based on a paper cut command (CUT/CMD) issued from the printer side. In the printing paper cutting method, when the paper is first set, a predetermined value is stored in the memory, and at the same time as the system starts operating, 1 is added to the memory contents each time the printer advances the paper by a unit length. Each time the paper is fed by a unit length in the post-processing machine, 1 is subtracted from the contents of the memory above (this counter value is called the path length).When CUT/CMD is issued on the printer side, the path length at that time is stored in the memory. The first feature is that the paper post-processing device subtracts 1 from the contents of the memory each time the paper is fed by a unit length, and when this subtracted value reaches a predetermined value, the paper is cut. , the second feature is that the memory mentioned in the first feature is provided in a ring with multiple addresses, and the path length is stored in the first address of the memory, and the first CUT
After the CMD is issued, the second cut is made before the paper cut based on the CUT/CMD is executed.
When CUT・CMD is issued, the first CUT・CMD is stored in the second address of the ring memory.
The unit length counted up between CMD and the second CUT/CMD is memorized, and in the same manner,
Each time CUT/CMD was issued, it was issued before.
If paper cutting based on CUT/CMD is not executed, the unit length counted up between the current CUT/CMD and the previous CUT/CMD is sequentially stored in the memory at the above multiple addresses. Also, if all the paper cuts based on the previously issued CUT/CMD have been executed, the above path length is stored in the memory at the above multiple addresses, and the paper is sent by unit length by the paper post-processing machine. 1 is subtracted from the contents of the first address stored in each case, and when that value reaches a predetermined value (for example, 0), paper cut is performed, and the above path length or
If the unit length counted up between CUT and CMD is stored, each time the paper is fed by a unit length in the paper post-processing machine, 1 is subtracted from the contents of that address, and that value becomes the predetermined value. The paper cut is executed at the point when the paper is cut, and the above operation is repeated.

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

FIG. 1 is an explanatory diagram of the drive system of an electrophotographic page printer (NIP) suitable for implementing the method of the present invention and a paper finishing machine (BTS) linked thereto, and is surrounded by dotted lines. The part with code 1 is NIP,
Part 2 shows BTS. 3 is a printing paper, 4 is a NIP developing machine, 5 is a photosensitive drum, 6 is a transfer section, 7 is a NIP tractor, 8 is a fixing device, 9 and 9 are heat rollers, and 10 is a guide roller. 1
1 and 11 are buffer rollers, 12 is a paper buffer, 13 is a BTS tractor, 14 and 14 are input rollers, 15 is a paper cutting blade, 1
6 and 16 are output rollers, 17 and 17 are puller rollers, 18 is a swing fin, 19 is a stack table, and 20 is a paper guide.

In the above configuration, the print paper 3 passes through the NIP tractor 7, the fixing device 8, the heat roller 9,
9, guide roller 10, buffer roller 11,1
1, the paper is stored in the paper buffer 12, and then passes through the BTS tractor 13, input rollers 14, 14, under the blade 15, passes between the output rollers 16, 16, and is transferred to the puller rollers 17, 17. Then, it is folded onto the stack table 19 by the swing fin 18. The output rollers 16, 16 are normally open, and when the part of the print paper 3 to be cut comes under the blade 15, the feeding of the paper 3 is stopped, the output rollers 16, 16 are closed, and the blade 15 is lowered. Then, cut the paper 3 at a predetermined location.

By the way, the cut point on paper printed out by a computer is usually the perforation after a series of jobs (JOB), and the cut position command (CUT/CMD) is used to cut the paper printed out by a computer. After the printing is finished, it is usually done immediately or after sending several dummy pages. To explain this with reference to Figure 1, the CUT/
CMD is given when the perforation of the paper 3 to be cut passes through the transfer unit 6. after that,
When the JOB continues and the perforated portion subjected to CUT/CMD reaches below the blade 15, the blade 15 descends to cut the paper. In addition,
When setting the paper 3, when one perforation is located at the transfer section 6, the other perforation should be located directly below the blade 15, in other words, the length of the paper from the transfer section 6 to the blade 15 should be There is no problem with setting the length to be an integral multiple of the length of one page of paper (from one folding perforation to the next folding perforation), but if the size of the paper used is different, the length from the transfer section 6 to the blade 15 described above may be Naturally, the paper length will also differ. However, NIP
and BTS are connected via a paper buffer 12 installed in the BTS, so if the paper 3 is slackened within this paper buffer 12,
Regardless of the page length of continuous paper, the paper length from the transfer unit 6 to the blade 15 can be made an integral multiple of the length of one page of paper of each size. For example, if a sheet of paper with a page length of 11'' is used and there are 8 pages, the paper length is 11×8=88″. now
If the length of 0.5'' is expressed as 1, the paper length for the above 8 pages can be expressed as 88×2=176.
On the other hand, the NIP tractor 7 generates a 1-pulse signal every time the print paper 3 is fed by 0.5'' (this paper feed information is called a Hip signal), and the BTS tractor 1
In step 3, one pulse signal is generated every time paper 3 is fed by 0.5″ (this paper feed information is
It is called BHip signal. In addition, each pulse mentioned above is
By attaching an encoder to the motor that drives the NIP tractor 7 and the BTS tractor 13 or to each tractor shaft, the signals can be easily extracted as Hip signals and BHip signals). Therefore, when paper 3 is first set, the number 176 is stored in the memory and the system starts operating.
When the Hip signal appears, add 1 to the memory contents,
If you always perform the operation of subtracting 1 from the contents of the memory when the BHip signal is output, the value in the memory can always represent the momentary paper length (the length from the transfer unit 6 to the blade 15) (this count value is called the path length). One job as printing progresses
has finished and this JOB outputs (prints)
When the computer judges that the paper to be cut is to be cut at the perforation next or several pages after the paper (last page of the JOB), the NIP controller issues CUT/CMD when the perforation passes through the transfer unit 6. It will be done. Taking this as an opportunity, the path length at that time is read by a counter and stored in memory. and,
Every time a BHip signal is output on the BTS side, if you subtract 1 from the memory contents, when the value reaches 0, the perforation where CUT/CMD was issued first reaches the bottom of blade 15. Therefore, it is sufficient to cut the paper at this point. In addition, since the BTS tractor 13 cannot actually stop instantly,
For example, if the paper length required from high-speed paper feeding to stopping is 1'', the motor deceleration of the tractor 13 will start when the memory value reaches 2, and then the tractor 13 motor will start decelerating when the memory value reaches 0. 13
However, if the cutting speed of the blade 15 is set to high speed and the cutting operation is performed immediately when the perforation where the CUT/CMD was being output reaches the bottom of the blade, it is possible to intentionally cut the paper 3. There is no need to stop it. Since the paper length from the transfer unit 6 to the blade 15 is relatively long, after a CUT/CMD is issued due to the completion of one job, the next or next paper cut based on that CUT/CMD is not executed. subsequent
CUT/CMD may be issued (for short jobs). In such a case, it is advisable to adopt the processing method described below.

That is, in addition to the counter Cp that calculates the path length, there is provided a counter CH that adds 1 every time the Hip signal is issued after CUT/CMD is output. Also, by providing memory at multiple addresses (for example, addresses 0 to n) (n is an integer), the contents of the memory at address 0 can be
The contents of the memory at address Mo and n are represented by Mn. Furthermore, the indicator is counted up one by one from 0 to n and returns to 0 when it becomes greater than n.
Provide types (i ₁ and i ₂ ). i ₁ means CUT/CMD is 1
It is a kind of ring counter that is counted up by one every time it is counted up and returns to 0 if there is the next CUT/CMD after it becomes greater than n. _i2 designates one of the multiple addresses _M0 to Mn in the memory described above, and each time the BHip signal is output, 1 is subtracted from the memory content at the designated address. Also, i ₂ is
Similar to i ₁ , when the final address n of memory is specified (i ₂ = n), 1 is subtracted from the contents of memory Mn every time the BHip signal is output, but the contents of memory Mn become 0. This is a kind of ring counter in which when i ₂ =0, that is, the memory returns to address 0.

When paper is first set, i ₁ = 0, i ₂ = 0,
M ₀ to Mn are all set to 0, and when the system starts operating and the first CUT/CMD is issued, the contents of the counter Cp that calculates the path length are i ₁ =
It is written to the memory at address 0 indicated by 0. Then, the count is increased to i ₁ =1, and at the same time, the counter _CH is cleared (=0). Assuming that the contents of the memory at address 0 are M ₀ , M ₀ is decremented by 1 each time a BHip signal is output. Also, every time a Hip signal appears,
The contents of _CH are incremented by 1.

When the contents of the memory M ₀ indicated by the indicator i ₂ are not 0, when the second CUT/CMD is issued, the contents of the counter _CH become 1 specified by i ₁ = 1.
Written to memory _M1 at address. And i ₁ =
The count is increased to 2, and at the same time, the counter _CH is cleared again. That is, in memory M ₁ ,
The paper length (inch x 2) sent by the Nip from the time the first CUT/CMD is issued until the second CUT/CMD is issued is written. When the contents of memory _M0 indicated by indicator _i2 are not 0, when the third CUT/CMD is issued, the contents of counter _CH are written to memory _M2 at address 2 specified by _i1 =2. It will be done. Then, the count is increased to i ₁ =3, and at the same time, the counter _CH is cleared.

On the other hand, when the BHip signal is output and the contents of the memory M ₀ eventually become 0, paper cutting is executed, and at the same time, i ₂ is incremented by 1, so that i ₂ =1.

When i ₂ =1, 1 is now subtracted from the contents of memory M ₁ every time the BHip signal is output. When the contents of memory _M1 are not 0, the fourth CUT・
When CMD is issued, the contents of counter C _H are i ₁
It is written to memory _M3 at address 3 specified by =3. Then, the count is increased to i ₁ =4, and at the same time, the counter _CH is cleared.

In the above example, the fourth CUT/CMD
If it is assumed that CUT/CMD is not issued after is issued, paper cut is executed when the content of memory _M1 becomes 0, and i ₂ =2. When i ₂ = 2, 1 is subtracted from the contents of memory M ₂ every time the BHip signal is output, and when the contents of memory M ₂ reach 0, paper cutting is executed, and i ₂ = 3. Become. When i ₂ = 3, each time the BHip signal is output, 1 is extracted from the contents of memory M ₃ .
is reduced and the contents of the memory _M3 become 0, paper cutting is executed, _i2 =4, and by repeating the above operation, the contents of the memories _M0 to Mn all become 0.

In this state, when CUT/CMD is issued again, the contents of the counter Cp are written into the memory _M4 indicated by i ₁ =4, and at the same time the counter _CH is cleared.

To summarize the above, if i ₂ = i ₁ and the content of the memory specified by i ₂ is 0, the current content of the counter Cp is written to the memory specified by the indicator i ₁ , and i ₂ ≠ i If the contents of the memory specified by ₁ or _i2 are not 0, the value of the _CH counter is written to the memory at the address specified by _i1 .

The above operations can be processed by a microcomputer according to the flowcharts shown in FIGS. 2 to 4.

Next, the operation of the present invention will be explained with reference to FIG.
Explaining according to Figures 2 to 4, Figure 2 is a flowchart for calculating the time change of the paper (paper length) set across the NIP and BTS, and Figure 3 is a flowchart for calculating the time change of the paper (paper length) set between the NIP and BTS. A flowchart for storing the CUT/CMD of the paper in the memory, and FIG. 4 shows a flowchart for detecting the cut position of the paper.

In Figure 1, there is now one perforation of the printing paper 3 in the transfer section 6 of the NIP, and the other perforation is directly below the blade 15 of the BTS, and the paper 3 has a page length of that paper. The buffer length is set to meet the standard, the NIP and BTS are both in the ready state, and when the start switch is turned on, the program branches to position E in FIG. First, write 0 to all of the memories M ₀ to Mn at multiple addresses used for CUT/CMD control,
Put 0 in the memory Fc as a flag, similarly put 0 in the memory F _B as a flag, and similarly put 0 in the memory F _B as a flag.
Also set 0 to indicators i ₁ and i ₂ used for memory addressing, both are 0, counter CH is also 0, and counter C _H is also 0.
The path length Lo is stored in Cp.

The path length Lo at startup is 88", taking 8 pages of 11" paper as an example, and assuming a length of 0.5" as 1, Lo = 88
Store x2=176 (decimal number).

Hip generated every time paper 3 is fed 0.5″ on the NIP side
The signal is determined, and if there is a Hip signal, 1 is added to the contents of counters C _H and Cp, and the contents are stored in C _H and Cp respectively (C _H = C _H + 1, Cp
=Cp+1). If there is no Hip signal, C _H and Cp
They don't work together. Next, when the perforation to be cut reaches the transfer section 6, CUT/CMD is issued, but when CUT/CMD is issued, a flag is
Fc becomes 1.

On the other hand, the BTS tractor 13 judges the BHip signal that is output every time the paper 3 is fed by 0.5″, and if there is a BHip signal, it subtracts 1 from the contents of the counter Cp and stores the contents in Cp again (Cp=Cp− 1), set flag F _B to 1. Also, if the memory content Mi ₂ at the address indicated by flag i ₂ is not 0, subtract 1 from Mi ₂ and write to the same address again (Mi ₂ = Mi ₂ - 1) .
If there is no BHip signal, leave F _B in the 0 state.

Note that the flags _FB , Fc, and _FD described above are all used only to facilitate program branching.

When the computer processing shown in FIG. 2 is completed, the program branches to the flowchart shown in FIG. 3.

In FIG. 3, it is determined whether the flag Fc is 1, that is, whether CUT/CMD has been issued,
When CUT/CMD is issued, it is determined whether indicator i ₂ is equal to i ₁ or not, and if i ₂ = i ₁ , it is determined whether the memory content Mi ₂ indicated by i ₂ is 0 or not. Determine whether If i ₂ = i ₁ and Mi ₂ is 0, it means that there is no part to be cut in the current path length, so the current value of the counter Cp is stored in the memory Mi ₁ indicated by the indicator i ₁ . The contents will be written. Then, Fc=0, and at the same time the counter C _H
is cleared and the value of indicator i ₁ is i ₁ = i ₁ +
It is counted up to 1.

As shown as step 13 in Figure 3, Fc≠
When it is 1, that is, when CUT/CMD is not issued, no operation is performed in this branch.

If i ₂ ≠ i ₁ in step 14, or if i ₂ = i ₁ but Mi ₂ ≠ 0, it means that there is a part of the path length where paper cutting has not been performed yet. , the contents of counter _CH are written to Mi ₁ indicated by indicator i ₁ . and counter C _H
is cleared and the value of indicator i ₁ is i ₁ = i ₁ +
It is counted up to 1.

In addition, step 19 in Figure 3 is the indicator
It is provided to return the value of the indicator i ₁ to 0 when the value of i ₁ exceeds the maximum memory address.

When the computer processing shown in FIG. 3 is completed, the program branches to the flowchart shown in FIG. 4.

In FIG. 4, it is determined whether the flag F _B is 1 or not, that is, whether or not the BHip signal is received in step 6 of _FIG .
), branch to the Y side in step 22, and F _B =
Set to 0. After the BHip signal appears several times,
As shown in step 24, Mi ₂ =2. This is assuming that the paper length required from high-speed paper feeding to stopping is, for example, 1", and the motor deceleration of the BTS tractor shown at 13 in Fig. 1 is set 1" before the scheduled cutting position (Mi ₂ = 2). Start and motor deceleration
Stop feeding paper 3 when it has advanced 1″ and prepare to cut the paper.

As mentioned above, when the contents of memory Mi ₂ are reduced to 2, a deceleration command is issued to feed paper 3, setting F _D to 1, and then the BHip signal is issued twice.
Mi ₂ = 0, and when paper cutting is executed, _FD is set to 0, and at the same time, the value of indicator i ₂ is i ₂ = i ₂ + 1.
will be counted up. Note that when the content of flag F _B is 0 and step 22 is entered, that is, BHip
When there is no signal, no operation is performed in this branch.

On the other hand, when Mi ₂ = 2 is not reached, paper cutting is not performed, and when F _D = 1 and Mi ₂ ≠ 0, or when i ₂ ≦ n, the contents of indicator i ₂ remain unchanged. There is no need to explain this again here.

After passing through the branch shown in FIG. 4, the instruction system of the program shifts to the branch shown at step 2 in FIG. 2, and thereafter the above operations are repeated.

Next, a concrete example of the present invention will be explained while applying numerical values.

In Figure 2, the value of n in the memory Mn is, for example, if the path length is 88'', the minimum page length to be processed by the BTS is 4'', which is 22 pages, so n = 22 is sufficient. However, considering the margin, we set n = 30. Therefore, the memory Mo is set to address 0, and the memory Mn is set to 30.
The address shall be the street address. In addition, in order to simplify the explanation, 1.
Use paper with a page length of 11″, and print CUT/CMD every 4 pages.
In other words, it will appear every 4 pages x 11 11/page = 44''.

(1) When the initial setting of the paper is completed and the operation is started, each memory and counter are initialized in step 1 of Fig. 2, and the counter Cp contains 176
(=88×2) is set. On the NIP side, where paper feeding has started, CUT/CMD is issued when the Hip signal outputs 44 x 2 = 88 pulses, but at this time, it is assumed that the BTS side is feeding the paper 46 inches. , it is assumed that the BHip signal outputs 46×2=92 pulses.

Initially, indicators i ₁ =0, i ₂ =0,
Furthermore, the contents of M ₀ to M ₃₀ are all 0.

When the first CUT/CMD is issued, the contents of counter _CH shown in step 3 in Figure 2 are
88 (counter Cp will be explained later),
The program branches to the Y side at step 4, and the flag Fc becomes 1. After starting operation, when the Hip signal outputs 88 pulses on the NIP side, the BHip signal outputs 92 pulses on the BTS side, so in steps 3 and 7, the contents of the counter Cp are Cp = 176 + 88 - 92
=172. Since i ₂ remained 0 and M ₀ remained 0 until now, it branched to the side at step 8. As mentioned above, since the flag Fc=1, the process branches to the Y side at step 13 in FIG. 3, and since i ₁ = i ₂ = 0 and M ₀ = 0, M ₀ The Cp value 176 is stored in
Fc=0, and in step 17, _CH returns to 0, and in step 18, i ₁ =0+1=1.

Also, the BHip signal has been output 92 times in the past, and each time it branched to the Y side at step 22 of the fourth time, but i ₂ =
0, M ₀ ≠ 2, F _D = 0, so in step 24 N
side, it also branched to the N side at step 26.

(2) Next, the paper is fed 4 pages (=44″) on the NIP side,
When the second CUT/CMD was issued, BTS
Assume that the paper is fed 43" on the side. At this time, Fc = 1 in step 10 of Fig. 2, counter C _H = 88 in step 3, and the contents of counter Cp in steps 3 and 7 1st CUT・
The contents of counter Cp after CMD is fired until the second CUT・CMD is issued is Cp
= 172 + (44-43) x 2 = 174. The indicator i ₂ = 0, the counter Cp value is written to M ₀ as described above, and after that, BHip becomes 43 × 2.
= 86, so M ₀ = 172-86 = 86.

In FIG. 3, since i ₁ = 1, i ₂ = 0 and i ₂ ≠ i ₁ , the contents of the counter _CH , that is, 44×2=88, are written in M ₁ through step 21, and in step 17, the contents of the counter _CH
=0, and i ₁ =2 at step 18.

In FIG. 4, after 172 is written in _M0 , the program passes through the N side at step 24 and also passes through the N side at step 26.

(3) Following (2) above, 4 pages of paper (=
44"), and when the third CUT/CMD is issued, the BTS side is assumed to have fed the paper 41.5 inches. At this time, in step 3 of Figure 2, C _H = 88 ( Counter Cp will be explained later),
Since CUT/CMD is hot, in step 10 Fc=
1. The contents of the counter Cp in steps 3 and 7 (the contents of the counter Cp after the second CUT/CMD is issued until the third CUT/CMD is issued) are Cp = 174 + (44 - 41.5)×2
= 179, memory M ₀ = 86 − 41.5 × 2 = 3, i ₂ ≠ i ₁
Therefore, in step 21 of Fig. 3, memory M ₂
The content 88 of counter _CH is written to . Then, counter C _H is cleared and i ₁ is cleared in step 18.
The count is increased to =3. Regarding FIG. 4, it is the same as (2) above.

(3)′ Now, as mentioned above, the content of M ₀ has become 3, but if the paper is fed an additional 0.5″ on the BTS side,
The content of M ₀ becomes M ₀ =2. Then the fourth
At step 24 in the figure, the process branches to the Y side, and the BTS sends a command to prepare for cutting to the paper feed control system and cutting control system, and F _D =1.
After that, when BHip is issued twice on the BTS side, paper feeding is stopped and paper cutting is performed.

After M ₀ = 2, F _D = 1, so in step 26 it passes through Y and when M ₀ = 0, it passes through Y side in step 27 and becomes _FD = 0 in step 28, and i ₂ = 1. Paper feeding will resume.

(4) After the third CUT/CMD on the NIP side, the paper is fed an additional 44″, and the fourth
When CUT・CMD is issued, it is assumed that on the BTS side, the paper has been fed 20″ since the memory M ₀ =0.
When the CMD occurred, the memory M ₀ = 3, so the BHip signal was issued 3 times before M ₀ = 0 (i.e., on the BTS side, the paper was fed 1.5"). Therefore, after the third CUT/CMD came out, the fourth
By the time CUT/CMD is issued, the BTS side has sent 20 + 1.5 = 21.5" sheets of paper.
At this time, Fc = 1 at step 10 in Fig. 2, counter C _H = 88 at step 3, and the contents of counter Cp at steps 3 and 7 (the third
After the CUT/CMD, the 4th CUT/
(Contents of counter Cp until CMD is issued)
is Cp = 179 + (44 - 21.5) x 2 = 224, and the indicator i ₂ = 1, so the memory
M ₁ = 88 - 20 x 2 = 48, in step 14 of Figure 3
Since i ₂ ≠i ₁ and i ₁ =3, the contents 88 of _CH are written into memory M ₃ . Also, M ₁ ≠ 2, F _D = 0
Therefore, the program branches to the N side at steps 24 and 26 in FIG.

If the above operation continues, the indicator i ₁ will eventually count to 30, but the path length will fall between 88''±30''.
Assuming that the paper feed speed of the BTS is controlled, it will never exceed 88″ + 30″ = 118″.Meanwhile, the indicator i ₁ will count up by 1 every 44″, up to a maximum of 118/44 = 2.7 <
Since the memory three addresses before must be 0, when i ₁ =30, the memories M ₀ to M ₂₇ must be at least 0. Therefore, when i ₁ = 31 in step 18 of FIG. 3, i ₁ = 30 in step 19, so i ₁ =
It returns to 0 and can be used repeatedly by cycling through memory addresses 0 to 30. The same thing can be said about the indicator i ₂ in step 28 shown in FIG _. 4, and when i ₂ =31, in step 29 it becomes
Therefore, i ₂ returns to 0, and memory addresses 0 to 30 can be cycled through and used repeatedly.

In the above embodiment, the paper feed information (Hip signal on the NIP side and
The above example shows the case where one pulse of the BHip signal (BHip signal on the BTS side) is generated, but the unit length of the paper feed mentioned above is
The unit length is not limited to 0.5'', and may be, for example, 0.1'' or any other unit length.

In addition, if the page length of the paper used for printing differs (if there are multiple paper sizes), the cut position will differ depending on the paper size, but the path length is determined for each paper. If you do this (for example, by reading constants from ROM), you will not have any problems with your work no matter what page length you use.

As described in detail above, according to the present invention, it is possible to issue a paper cut command without adopting the conventionally proposed marking method, and the entire paper surface can be
Can be used to print JOB.

Further, according to the present invention, after a CUT/CMD is issued due to the completion of one JOB, that CUT/CMD is issued.
If the next or subsequent CUT/CMD is issued before the paper cut based on CMD is executed, that is, even if the paper feed on the NIP side and BTS side operate randomly, the paper cut will not be executed. There was no problem, and it was issued on the NIP side.
Based on CUT/CMD, the BTS can perform accurate paper cutting in sequence, making it possible to provide a highly practical printing paper cutting method.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory diagram of a drive system of a printer (electrophotographic type) suitable for implementing the method of the present invention and a paper post-processing machine linked thereto, and FIG. is the paper set between the printer and the paper post-processing machine (paper length)
FIG. 3 is a flowchart for storing the paper cut command (CUT/CMD) in memory, and FIG. 4 is a flowchart for detecting the paper cut position. 1...Printer (NIP), 2...Paper feeder (BTS), 3...Print paper, 4...Developer,
5... Photosensitive drum, 6... Transfer section, 7... NIP tractor, 8... Fixing machine, 9... Heat roller, 1
0...Guide roller, 11...Buffer roller,
12...paper buffer, 13...BTS tractor,
14... Input roller, 15... Paper cutting blade, 16... Output roller, 17...
... Puller roller, 18 ... Swing fin, 19
...Stack table, 20...Paper guide,
Cp...Counter, C _H ...Counter, _M0 ~ Mn...
...Memory contents, i ₁ ...Indicator, i ₂ ...Indicator, F _B ...Flag, Fc ...Flag, F _D
... Flag, Lo ... Length (path length) from NIP transfer section 6 to BTS blade 15, Mi ₁ ... Contents of memory indicated by indicator i ₁ , Mi ₂ ...
The contents of memory indicated by indicator i ₂ .

Claims (1)

[Scope of Claims] 1. A printer and a paper post-processing device having paper cutting means are connected via a paper buffer, and a paper cutting command is generated on the printer side when a cut fold of the paper passes a reference position of the printer. In the print paper cutting device that detects the cut fold of the paper and cuts the paper on the paper post-processing machine side, the first counting means is n-adic and increases by one count each time the cutting command is issued, and the post-processing A second n-ary counting means counts up by one each time the paper cutting operation is performed on the machine, and counts up and counts down by one each time the paper is fed by a predetermined unit amount on the printer side and finisher side, respectively. A paper path length counting means is loaded with a value obtained by converting the paper path length from the reference position of the printer to the position of the paper cutting means into a predetermined unit feeding amount of the paper at the time of setting; A third counting means increments the count by one each time the quantity is sent, and is cleared each time the cutting command is issued; When the count values of the first counting means and the second counting means are equal and when they are not equal,
The count values of the paper path length counting means and the third counting means are respectively loaded, and each time the paper is fed by the predetermined unit amount on the paper processing machine side, the count value of the address corresponding to the count value of the second counting means is loaded. a storage means that counts down by 1, and drives the paper cutting means to cut the paper when the count value of the address corresponding to the count value of the second counting means of the storage means reaches 0. Featured printing paper cutting method.