JPS6212550A - Control device for conveying feed paper - Google Patents

Abstract

PURPOSE:To prevent a sheet of paper from jamming in an intermediate conveying device by stopping said intermediate conveying device at a certain timing after a leading sheet of paper has reached a record feed roller. CONSTITUTION:The delivery of paper from a feed paper table 1 is started in accordance with a paper feeding indication from a feed paper control means, and an intermediate conveying device 2 is energized for feeding to deliver sheets of paper at a defined interval. In this case, when a record feed roller 3 is in a driven condition for feeding a sheet of paper into a recording part, the delivery of paper from the paper feed table 1 at the defined interval is continued and, when a leading sheet of paper in the intermediate conveying device 2 is in the area in front of the record feed roller 3 by the amount of a certain distance slightly longer than a distance Ld between the feed paper table 1 and the intermediate conveying device 2, the delivery of paper is stopped and, as the record feed roller 3 is stopped, the intermediate conveying device 2 is stopped after the leading sheet of paper reached a record feed roller 3.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a paper feeding and conveying device for a recording device, and in particular, the present invention relates to a paper feeding and conveying device for a recording device, and in particular, for example, a paper feeding and conveying device for a recording image forming means in which an image forming surface moves at a constant speed, such as a photoreceptor drum of a copying machine. The present invention relates to a paper feed conveyance control device for sending paper.

(2) Prior Art For example, in an electrophotographic copying machine, recording paper is selectively fed to a photosensitive drum from a plurality of paper feed trays to transfer a developed image on the drum. A paper feed conveyance system (intermediate conveyance device) is provided between each of the paper feed trays and the transfer section (recording section on paper). The paper feed interval from the paper feed table is made equal to the copy repeat interval. There is a registration roller (
This registration roller is stopped, and after the leading edge of one sheet of paper hits the registration roller, the registration roller is driven to send the paper to the photoreceptor drum. The feeding of paper from the paper feed table to the paper feed conveyance system is stopped once the paper on the paper feed table is transferred to the paper feed conveyance system, and resumed after the elapse of the repeat interval. The paper feed conveyance system is continuously energized until the set number of copies are completed. As a result, the paper is fed from the paper feed conveyance system to the registration rollers, the leading edge of one sheet hits the roller, and the registration rollers are driven at the timing when the leading edge of the paper is slightly bent. This is to prevent the paper being sent to the recording section (transfer section) from skewing and to ensure accurate alignment of the image on the photosensitive drum and the paper.

During this paper feeding, if the drive of the registration rollers is delayed after the leading edge of a sheet hits the registration rollers (or if the paper reaches the registration rollers early), the amount of slack (curvature) at the leading edge of the paper will increase, leading to folds or jams. etc. Also,
If the registration rollers are driven too quickly (or if the paper reaches the registration rollers too late), the registration rollers will not be fed or the registration will be misaligned (recorded image misalignment). In order to prevent these troubles, the paper feeding timing to the registration rollers and the drive start timing of the registration rollers are set accurately, but due to the delayed start of driving of the registration rollers in anticipation of paper slipping on the paper feed rollers. , or due to unplanned start of drive due to paper slip, etc. Even if the timing settings are accurate, registration roller drive or paper feeding may be delayed, resulting in recording paper jamming or image misalignment on recording paper. . This is particularly problematic when the paper conveyance path between the paper feed table and the registration rollers is long, since the amount of paper slip and skew becomes large. This problem can be solved by providing a clutch for each of the conveyance rollers of the intermediate conveyance device that sends the paper fed from the paper feed tray to the registration rollers, or for each predetermined group of conveyance rollers. proposed to stop after a predetermined time when the leading edge of the paper it sends hits the registration roller, and to keep the paper feeding tray side transport roller of the intermediate transport device in the paper feeding state even during this stop. According to this, it is not necessary to match the paper feeding pitch of the intermediate conveyance roller to the copy repetition pitch, and the paper can be fed to the registration rollers and stopped sufficiently before the registration rollers start driving. . When the registration rollers are driven (at the start of recording), paper is always being supplied to the registration rollers, so the probability of jamming, skewing, or image misalignment is extremely low.

However, in this case, the intermediate conveyance device requires multiple clutches that selectively connect the conveyance rollers therein to the power system (photoreceptor drum drive system). In the case where the paper feed table is provided at a position quite far from the photoreceptor drum, such as when an intermediate paper feed table is provided, the length of the intermediate conveyance device is long, and the number of clutches used therein is increased. Furthermore, as the number of clutches increases, control of the paper conveyance system becomes more complicated.

■Purpose The present invention uses an intermediate conveyance device with a simple configuration to feed paper to recording paper feed rollers such as registration rollers, and moreover, reduces the occurrence of jams on the recording paper feed rollers, and prevents skinny recording paper and misalignment of recorded images. purpose.

■Structure In order to achieve the above object, the present invention provides a paper feed control means for controlling feeding of paper from the paper feed table and feeding bias of the intermediate conveyance device: Start feeding the paper, feed the intermediate conveyance device and feed the paper at predetermined intervals, and when the recording feed roller is in the driving state to feed paper to the recording section, continue to feed the paper from the paper feed table at predetermined intervals, When the leading paper of the conveyance device is in the area in front of the recording feed roller by a predetermined distance that is slightly longer than the distance Ld between the paper feed tray and the intermediate conveyance device, the above-mentioned paper feeding is stopped, and when the recording feed roller stops, the leading paper is It is assumed that the intermediate conveyance device is stopped after the paper reaches the recording feed roller.

According to this, the intermediate conveyance device selectively connects all of the paper conveyance rollers therein to a power system, such as a photosensitive drum drive power system, by one clutch.

It has a simple configuration with few mechanical elements, and allows paper to be fed from the paper feed table at intervals shorter than the recording repetition interval, fed to a recording feed roller, for example, a registration roller, and then stopped sufficiently before the drive of the registration roller starts. , thus reducing paper jams.

It also reduces paper skew and recorded image misalignment. When the recording feed roller is stopped, feeding of paper from the paper feed tray is stopped when the leading paper of the intermediate conveyance device is within the range before the recording feed roller, so that the feed of paper from the paper feed tray is shorter than the recording repetition interval. Even if paper is fed out at short intervals, the leading edge of the paper fed out from the paper feed table will not stop between the paper feed table and the intermediate conveyance device, and misfeed from the paper feed table will not occur. In addition, when the recording feed roller is stopped, the intermediate conveyance device stops at a predetermined timing after the first sheet of paper reaches the recording feed roller, so there is a large amount of paper in the intermediate conveyance device that can cause a jam. It doesn't bite the paper. When the recording feed roller is being driven, the paper sent out from the intermediate conveyance device is sent to the recording section by the recording feed roller. When the first sheet of paper stops at the recording feed roller section, the feeding of paper from the paper feed tray to the intermediate conveyance device is stopped. No paper is added.

In a preferred embodiment of the present invention, let t2 be the interval between paper feeds from the recording feed roller to the recording unit, ta be the time it takes for the paper to reach the intermediate conveyance device from the paper feed tray, and t4 be the set margin time. It is assumed that the paper feed control means feeds paper from the paper feed table at a repeating interval of t1=t2 (ta+t4).

That is, ta is the time during which the paper fed out from the paper feed table advances by Ld, and t3+t4 is the time during which the paper advances by L in the intermediate conveyance device. Therefore, t1 to t4 are based on the count value of pulses synchronized with the constant speed rotation of the image forming means of the recording section, and the sheet feeding control means counts the pulses while the intermediate conveying device is in the feeding state. It is assumed that t1 to t4 are measured and the counting is stopped when the intermediate conveyance device stops.

According to this, 1. For example, if the recording section is the transfer section of an electrophotographic copying machine, the paper feed is controlled in synchronization with the rotation of the photoreceptor drum, and the position of each paper fed out from the paper feed table is counted. The count value of the same pulse is tracked based on the value to control the drive timing of the recording feed roller, that is, the registration roller, to control the timing of feeding the paper from the paper feed tray, and to control the timing of feeding the paper to the registration roller of the intermediate conveyance device. This can be done based on the following.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

FIG. 1 shows an outline of the mechanism of an embodiment of the present invention.

This embodiment is an electrophotographic copying machine, and a document placed on a contact glass 5 and pressed by a press plate 4 is illuminated by a lamp 6. The light reflected from the original is reflected by the first mirror 7 and the second mirror.
Mirror 8. Third mirror9. The light is projected onto the photosensitive drum 17 by the lens unit 15 and the fourth mirror 16 . The drum 17 is driven to rotate clockwise, and the main charger 18
The surface is uniformly charged. The charged surface is exposed by the light projection described above, resulting in a latent image corresponding to the m-stripe image. The latent image is developed by a developing unit 19 to become a developed image. The developed image is transferred to the recording paper fed by the registration roller (recording feed roller) 3 directly below the transfer/separation charger 20, and the transferred paper is separated from the drum 17 and fixed via the relay conveyance device 12a. It is sent to the container 10. Note that the photosensitive drum 17
The ramp 6 and the first mirror 7 are driven to the right at a speed equal to the circumferential speed multiplied by a predetermined ratio, and the second mirror 8 and the third mirror
The mirror 9 is driven to the right at half the scanning speed of the lamp 6 so that the optical path length from the document scanning position to the lens unit 15 is constant.

The paper exiting the fixing device 10 is sent to a paper output tray 22 or an intermediate cassette 1 for double-sided copying. Namely.

When the switching gate 11 is in the illustrated position, the paper is sent to the paper discharge tray 22, and when the switching gate 11 is in the position rotated about 30 degrees counterclockwise from the illustrated position, the paper is sent to the intermediate cassette l.

The main body of the copying machine has four cassettes 24C as paper feed trays.
, 25G, 26C, and 27G and the intermediate cassette 27G are installed, and between these cassettes and the registration rollers 3 there is an intermediate conveying device 2.

Paper feed roller 24 that feeds paper from each of cassettes 24C, 25C, 26C, 27C and 1 to intermediate conveyance device 2
, 25, 26, 27, and 28 are each connected to a photosensitive drum drive power system (not shown) via an electromagnetic clutch (not shown). In addition, the conveyance rollers that feed the paper at each position of the intermediate conveyance device 12 are all connected to the same power transmission means (chain or belt: not shown), and a gear or pulley (not shown) that drives this power transmission device.
(not shown) is coupled to the photosensitive drum drive power system via one electromagnetic clutch.

The switching gate 11 is rotated counterclockwise by a solenoid (not shown).

A paper feed roller 13 is located above the intermediate cassette 1 and is pivotally attached to the tip of an arm L3a. This paper feed roller 13
is connected to the photosensitive drum drive power system via an electromagnetic clutch (not shown). The rear end of the arm 13a is pivotally attached to the equipment frame, and is rotated counterclockwise by a solenoid device (not shown). When sending paper from the fixing device 10 to the cassette 1, the electromagnetic clutch for controlling the switching gate 11 is energized, the gate 11 rotates counterclockwise, and the paper is guided to the relay conveyance device 12c. L
2c is connected to the photosensitive drum drive power system by an electromagnetic clutch (not shown) and feeds the paper toward the cassette 1. When the paper falls onto the cassette 1, the solenoid device that drives the arm 13a is energized to press the roller 13 against the paper in the cassette 1, and the roller 13 is connected to the photoreceptor drum drive power system by an electromagnetic clutch. The paper is fed under the paper feed roller 28. A paper sensor 14 for determining the drive timing of the rollers 13 is disposed on the output side of the relay conveyance device 12c, and a paper sensor for detecting paper jam is installed between the registration rollers 3 and the exit of the intermediate conveyance bag [2]. 3a
is installed.

FIG. 2 shows an electrical system for controlling the energization of each part of the mechanism shown in FIG. Switches 61 such as input switches, status detection switches, and status setting switches for each part of the copying machine are as follows:
It is connected to the microprocessor 58 via buffer amplifiers 59 and 60, and also to the driver 68. Interrupt input port IN of microprocessor 58
A drum synchronization pulse generator 62 is connected to T. The pulse generator 62 includes a photosensor 62S that detects a light-transmitting slit in a rotary plate coupled to the photoreceptor drum 17. Every time the drum 17 rotates by a minute angle, the sensor 62
S detects a transparent slit and interrupts 1 pulse to input port I
Give to NT. At the A/D conversion input port AD1 of the microprocessor 58.

A temperature detection circuit 63 that detects the temperature of the fixing section of the fixing unit 10 is connected. Thermistor 63 generates a voltage corresponding to the temperature of the fixing section, and applies this to ADl. The toner concentration detection unit 36 is connected to the A/D conversion input port AD2 of the microprocessor 58. The microprocessor 58 has a ROM 67 and a RAM 6 via an address bus, a control bus, and a data bus.
6° and input/output port buffer elements 64 and 6
5 is connected. These input/output boat buffer elements 64 and 65 have drivers 68 to 71, respectively.
and drivers 72 to 75 are connected.

Driver 68 sequentially applies a switch state read signal to each of the Y scan lines of switch matrix 61 and sequentially applies a display element activation signal to each of Y scan lines of display element matrix 76.

Each signal on the X line of the switch matrix 61, ie, a signal indicating whether each switch is open or closed, is provided to the microprocessor 58 via buffers 59 and 60. Microprocessor 58 applies display element activation signals to each of the X lines of display element matrix 76 via buffers 69.70, if desired. In the display element matrix 76, the display elements to which the Y line display energizing signal and the X line display energizing signal are simultaneously applied are lit. A mechanism driving element (such as a main motor), which is not shown, is connected to the driver 71.

The driver 72 includes electrical elements of the imaging system (lamp 10,
Chargers 4, 72, etc.) are connected to the drivers 73 and 74, and electric elements (clutches and solenoids Wt) of the paper conveyance system are connected to the drivers 73 and 74. In Figure 2, 2CL is an intermediate transport bag! ! ! The electromagnetic clutch 3CL connects the power transmission means (for example, a chain) of No. 2 to the photoreceptor drum 17 drive power system, and the electromagnetic clutch 3CL connects the registration roller 3 to the photoreceptor drum 17 drive power system.

11SL is a solenoid device for rotationally driving the switching gate 11 in a counterclockwise direction, and 12CL is a relay conveyance device 12.
the conveyance roller of a, the conveyance roller or drum of the fixing device 10;
The discharge conveyance roller 12b and the relay conveyance roller 12c,
An electromagnetic clutch 13CL connects the entire set to the photoreceptor drum 17 drive power system via a power transmission means (for example, a chain), and an electromagnetic clutch 13CL connects the paper feed roller 13 to the photoreceptor drum 17 drive power system. clutch, 1
3SL is a solenoid device that rotationally drives the roller arm 13a in a counterclockwise direction; 24CL and 25CL;

26CL, 27CL and 28CL feed paper rollers 24, 25, 26, 27 and 28, respectively, to the photosensitive drum 1.
7 This is an electromagnetic clutch for connecting to the drive power system.

Connected to the driver 75 is a connector for connecting electrical elements such as devices installed in the copying machine, such as a feeder and a sorter.

The microprocessor 58 operates the drivers 68 to 68 according to the input operations of various switches and the status of each part of the copying machine.
75 with various energizing signals.

FIG. 3a shows an overview of the control operation of the microprocessor 58. To explain this, when the power is turned on, the processor 58 initializes (step 1: hereinafter referred to in parentheses as "
(omitting the word "step"). At this time, the photosensitive drum 17 is set to rotate (pre-rotation), cleaning is set, pre-rotation time is set, warm-up energization of the fixing device 10 is started, and a warm-up timer is set. mode, and proceeds to the heat-up standby mode (2), where the temperature of the fixing device 10 is detected,
When the pre-rotation time has passed, the light drum 17 is stopped.

When the temperature of the fixing device 10 reaches the set value, this heat-up standby mode (2) is exited. If the warm-up timer exceeds the set value, it is determined that an abnormality has occurred and the process proceeds to abnormal mode (23) (3). In this abnormality mode, power supply to the heater of the fixing device 10 is reset, and a lamp indicating a heater abnormality and a serviceman call lamp are turned on. If an abnormal mode cancellation instruction is input here, the lamp and flag are cleared and the process returns to the heat-up standby mode (2).

Now, when the temperature of the fixing device 10 reaches the set value before the warm-up timer times out, the non-use standby timer is set, the reading of the operation board is set, and the key-in of the operation board is waited for. A typical example of key-in is turning on the copy start key. Other typical examples include turning on the numeric keypad to set the number of copies and inputting the copy magnification. When the unused standby timer times out (4), the process advances to unused standby mode (5). When entering this non-use standby mode, first, a preheating standby timer is set, and the heater energization of the fixing unit 10 is switched to low heat generation energization for the non-use standby mode.
Wait for the preheat key to turn on (6: Monitor only the preheat key on the operation board). When the preheating key is turned on, the process proceeds to heat-up standby mode (2).

If the preheating standby timer times out without the preheating key being turned on (7), the machine advances to machine stop mode 8, where the main power relay is turned off (self-holding release of the main power relay). As a result, the entire electrical system such as the processor 58 shown in FIG. The source falls.

Now, when there is an input from the operation board while waiting for the standby timer to time out in step 4, if it is a copy condition input (number of copies, doubling ratio, density, etc.), the process goes to ready mode 10, and the input copy conditions are input. set. Also, it reads the status of each part and determines whether copying is possible, and also determines the copying magnification and paper feed size. If copying is not possible, the process goes to (11) abnormal mode 23, and if copying is possible, it is returned to error mode. Set the standby timer and wait for the copy start key to turn on.

If this is not turned on and the standby timer times out.

Proceed to unused standby mode 5. When the copy start key is turned on, the process advances to pre-copy mode 14, where the rotation of the photoreceptor drum is started (pre-copy cleaning), a timer for one rotation of the photoreceptor drum is set, and the paper feed cassette is opened. Check which paper cassette is
If it is 26G, 27G, or 1, which is relatively far from the photosensitive drum 17, paper feeding (driving of the paper feeding roller and driving of the intermediate conveying device 2) is started here, and when this is started, paper trouble detection is started. When the first paper fed reaches the registration roller 3 within a predetermined time (detected by the sensor 3a),
Proceed to copy mode 17.

If it does not reach the specified time, a paper feed error (15
) to proceed to abnormal mode 23. Paper cassette is 24G
Or, in the case of 25G, paper is not fed in the pre-copy mode 14, but paper is fed in the copy mode 17. Note that the detailed contents of the pre-copy mode 14 will be described later.

In copy mode 17, the paper feed cassette is referred to, and if the paper feed cassette is 24G or 25G, paper feeding (roller drive) is started, and the process waits until one paper is detected by the sensor 3a ( If it is not detected within a predetermined time, the process proceeds to abnormal mode 5), and a copy cycle begins. This copy cycle is generally similar to what is conventionally known. However, when the paper feed cassette is 26C, 27C, or 28, paper feeding starts in pre-copy mode 14, so there is an additional process corresponding to this, so the paper feeding control routine (pre-copy mode 14: detailed The paper feed control routine 30 is shown in FIG. 3b; details are shown in sections 3d and 3e.

3g, 3h + 3i, 3j, and 3). Also, as shown in Fig. 3m, when the registration roller 3 is on timing (141=Y), the registration roller 3 142).

For implementation of the invention, an intermediate transport bag! i! After turning on the clutch 2CL that drives the paper feed roller (143),
26, 27, or 28) in that it includes a subroutine (144) for clearing the paper feed clutch prohibition flag indicating whether driving (paper feeding) is possible. The other parts of the control aspect of the copy mode 17 are the same as the conventional one. In this copy mode 17 as well, abnormality checks such as paper jam detection are performed as in the conventional case, and if an abnormality is found (18), the process advances to abnormality mode 23. If there is no abnormality, the number of copies is accumulated, and it is checked whether the accumulated value reaches the set number of copies. When the number of copies is reached, the copy end mode 20 is activated.
Proceed to. If the set number of copies has not been reached, the process proceeds to copy mode 17 again. In the copy end mode 20, cleaning is continued and the photosensitive drum 17 continues to rotate until the transfer paper is fed into the paper discharge tray 22 or the intermediate cassette 1,
It also performs abnormality checks such as paper jam detection.

If an abnormality is detected, the process proceeds to abnormality mode 23. Note that when entering the copy end mode 20, an end timer is set and the operation board is read. When copy start key ON is read in copy end mode 20, the process advances to pre-copy mode 14. If the start key is not turned on and the end timer times out, the process advances to warm-up standby mode 2.

FIG. 3b shows the contents of the pre-copy mode 14.

In this pre-copy mode 14, initial conditions are first set (25). That is, setting or initializing various flags for executing a copy cycle.

Set the timing data. Also, the set value for the number of copies is assigned to the paper feed counter. The content of the paper feed counter is updated to a smaller value by 1 every time a sheet of paper is fed out by the paper feed roller 24, etc., and when the content of the paper feed counter reaches 0, the start key is turned on again. Until then, feeding of the paper by the paper feed roller 24 and the like is stopped.

When the initial condition setting 25 is completed, the photosensitive drum 17 drive power system is energized (26). That is, the main motor is energized to rotate the drum 17 at a constant speed.

Next, the process advances to the initial paper feeding routine 27, where the paper feeding cassette is
．． If the 4th cassette 2.6G, 27C or intermediate cassette 1 is set, paper feeding starts, and if the 1st or 2nd cassette 24C or 25C is set to feed paper, an error check is performed as is. Proceeds to routine 28, and if paper feeding has started, proceeds to abnormality check routine 27, where it checks for abnormality in paper feeding, and if there is an abnormality (2
9) Proceed to abnormal mode 23. If the condition is normal, the process proceeds to the paper feed control routine 30 (details are shown in Figure 3d), first proceeds to the copy preprocessing routine 31, and when the copy preprocessing is completed (3).
2) Proceed to copy mode 17 of the main routine (Figure 3a).

FIG. 3c shows the initial paper feeding routine 2 in the pre-copy mode 24.
7 details are shown. To detect this smell, first check which cassette is designated as the paper source.33-35)
If it is the first cassette 24C or the second cassette 25C, the pre-copy mode 24 is set so that paper is not fed here.
(proceed to step 28). When intermediate cassette 1 is designated as paper feed, set the count of counter A to the drum synchronization pulse count up to start the count.)
, when the third cassette 26G is designated as paper feed, counter B starts counting, and the fourth cassette 27G starts counting.
When C is designated for paper feeding, counting of counter C is started (36). When counting starts, the clutch 2CL for connecting the intermediate conveyance device 2 to the drum drive power system is energized (37), and the paper feed counter (in step 25) (in which the set number of copies is stored) is updated to a smaller value by 1 (38), and the paper feed rollers 28, 2.
Set the electromagnetic clutch 28CL, 26CL, or 27CL that connects 6 or 27 to the drum drive power system to bias (
39-44).

As a result, paper feeding from the cassette (1, 26C or 27C) is started. And abnormality check routine 2
Proceed to step 8. Here, when paper feeding is started, a counter is set to check for paper feeding abnormality, and conditions that affect other copying processes are referred to, and when a copying impossible condition is detected, the process proceeds to abnormality mode 23.

The contents of the paper feed control routine 30 will be explained with reference to FIG. 3d. Here, it is checked whether or not paper feeding has already started (45 to 47), and if paper feeding has not started, the process advances to the copy preprocessing routine 31.

When paper feeding starts, pulse count routine 31
(Fig. 3f), paper feed clutch off routine 49 (3rd
g) Secondary paper feed ON routine 50 (FIG. 3H), paper feed clutch inhibit routine 51 (FIG. 31), paper feed clutch ON routine 52 (FIG. 3J), and transport latch off routine 53 (FIG. 3) ) and then copy preprocessing routine 3.
1 (Figure 3b; details in Figure 3e).

In the pulse count routine 31 (Fig. 3f), a flag indicating whether or not a drum synchronization pulse has appeared from the last exit to this routine to the current entry is set in the drum synchronization pulse interrupt processing. If this flag is set, clear this flag and first set counters S and D to 1.
The count is increased, and then it is checked whether or not the intermediate conveyance device 2 is being driven, and if it is being driven, the counter A is
.

Increase B and C by 1 count. The process then proceeds to a paper feed clutch off routine 49. If the flag indicating the appearance of a drum synchronization pulse is not set, the process immediately proceeds to paper feed clutch off routine 49. In this pulse count routine 48, when the intermediate conveyance device 2 is set to drive (during paper feeding), counters A, B, and C are counted up, and the intermediate conveyance device 2! 2 is stopped, the paper is stopped in the intermediate conveyance device 2, so the counter A,
Note that B and C are not counted up.

To explain the paper feed clutch off routine 49 (3rd g), first check which cassette is set for paper feed. If it is 26C or 27C, the process advances to the next paper feed on routine.

If the cassette set to feed paper is intermediate cassette 1, in this case, counter A starts counting when paper is fed out from cassette 1, so refer to the contents of counter A (70), and it is larger than Ld. If the count value is 80 or more, which corresponds to a time corresponding to a rather long distance (the time required to transfer the paper from the cassette 1 to the device 2, taking into account slippage of the paper on the rollers 28), the paper is not accepted into the device 2. Therefore, the clutch 28CL connected to the roller 28 is deenergized (
off) (71). If the paper feed cassette is the third or fourth cassette 26C or 27G, the counter B or C starts counting.

Compare its contents with the reference value 70, which is equivalent to a time sufficient to pass the lock from the cassette 26G or 27C to the device 2 (73).
, in order to stop the roller 26 or 27 when the count value is 70 or more, the clutch 26CL or 2 connected thereto
7CL is turned off (74).

Intermediate cassette 1. Third or fourth cassette 26C or 27
Regardless of which cassette C is set to feed paper, if the contents of counters A, B, or C do not reach a count value equivalent to the roller drive time, steps 71 and 74 turn off the clutch for roller drive. Bypass the next paper feed routine 5
Go to 0. In other words, the roller drive clutch is not turned off.

In the next paper feeding routine 50 (3h), first check whether the content of the paper feeding counter is 0 (76), whether the paper feeding counter is 0 (paper has been fed out for the set number of copies), and if it is 0. If it is, the process advances to the paper feed clutch prohibition routine 51 (because paper feeding is not necessary). 77.84.85), and if it is intermediate cassette 1, it will be loaded into the intermediate cassette 1. Referring to the size of the recording paper currently in use (78, 80, 82), the counter determines whether the feeding timing is such that double feeding will not occur (whether the trailing edge of the paper sent out last time has come out of cassette 1). Please refer to the contents of A and make a decision.79,81.83)
If the value indicates the feed amount corresponding to the size of the stored recording paper, the primary paper feed clutch on request flag is set (92), and the process proceeds to the paper feed clutch prohibition routine 51. When the paper feed is set to the third or fourth cassette 26G or 27G, it is determined whether or not the next paper feed is possible by referring to the counter B or C (86 to 91), and it is possible. Then, the next paper feed clutch on request flag is set to zero (92). If it is still not possible, this flag is not set and the process proceeds to the paper feed clutch prohibition routine 51.

In the paper feed clutch prohibition routine 51 (Fig. 31), first check which paper feed setting cassette is 93, 97, 101), and if it is intermediate cassette 1, the counters A, B, and C are set. Referring to the contents, if any of the contents indicates that the paper being fed by the intermediate transport device Wt2 is in the roller feeding prohibited area (range from the registration roller 3 to before L, the count value is 535 to 535 + 80).
Check whether it is in the range (!I) (94-96
), if it is within that range, the paper feed clutch prohibition flag is set (105).In addition, in the case of paper feeding from intermediate cassette 1, the paper fed out from cassette 1 is received by device 2, and the next When paper is fed out, the contents of counter B are transferred to counter C, the contents of counter A are transferred to counter B, and counter A is counted up from 0.

The content of the counter having the count content with the largest number of counts indicates the position of the leading edge of the first paper in the intermediate conveyance device 2. For example, when one sheet of paper is fed out and the next sheet is not fed out, counters A, B, and C all indicate the same content, that is, the position of the leading edge of the paper fed to the intermediate conveyance device 2. When two sheets of paper are fed out, counter B
and C indicate the position of the leading edge of the first paper, and counter A indicates the position of the leading edge of the next paper. In addition, when three sheets of paper are fed out, counter C indicates the position of the leading edge of the first sheet of paper, counter B indicates the position of the leading edge of the second sheet of paper, and counter A indicates the position of the leading edge of the third sheet of paper. Indicates the location of When the fourth sheet of paper is fed out, counter C indicates the leading edge position of the second sheet of paper, counter B indicates the leading edge position of the third sheet of paper, and counter A indicates the leading edge position of the fourth sheet of paper. shows. Note that the first sheet of paper is sent out from the registration roller 3 to the transfer section. Therefore, the maximum value of the contents of the run, A, B, and C indicates the position of the leading edge of the foremost paper in the intermediate conveyance device 2. Note that the count value 535+80 corresponds to the length of the paper feed path from the intermediate cassette 1 to the registration roller 3.
The count value 210+80 corresponds to the length of the paper feed path from the third cassette 26G to the registration roller 3, and the count value 410+80 corresponds to the length of the paper feed path from the fourth cassette 27C to the registration roller 3. Of these length-corresponding count values, the number 80 corresponds to the paper feed roller drive prohibition area. Therefore, when the paper feed cassette is the third cassette 26C, if the content of any one of counters A, B, and C is 210 or more, the paper feed clutch prohibition flag is set. When the cassette is the fourth cassette 27C, the counter A,
If the content of either B or C is 410 or more, a paper feed clutch prohibition flag is set (101 to 104.
105). In either case, counters A, B and C
Any content of 535 or more (cassette l paper feeding), 21
If it is not 0 or more (cassette 26C paper feeding) or 410 or more (cassette 27G paper feeding), the first paper is in the prohibited area (range 80+wm before the registration roller 3, the period of the Nidrum pulse corresponds to a movement of 1m11). Since the paper feed roller can be driven, the paper feed clutch prohibition flag is not set and the process proceeds to the paper feed clutch on routine.

In addition, the conveyance device starts from the intermediate cassette 1! ! The length to the No. 2 conveyance roller is 60LIIIl, and the length to the No. 2 conveyance roller is 60LIIIl.
The length from the fourth cassette C and the fourth cassette 27C to the conveying roller of the conveying device 12 is 50 mm. Since one cycle of the drum synchronization pulse corresponds to 11, the count number 60 corresponds to the length from the intermediate cassette 1 to the conveyance roller of the conveyance device 2. The above-mentioned prohibited area 80+sm (count number 80) is the distance between the cassette 1 and the transport device 2! a60III1
This is the value obtained by adding the allowable paper feed slip length of 20 III to roller 28 or roll registration roller 3 (not included).

As will be described later, when the leading paper enters this prohibited area, new feeding from the cassette 1.26C or 27C is prohibited. This stops the conveyance device 2 when the first paper reaches the registration roller 3, but at this time the cassette 1
．． In order to prevent the paper fed out from 26C or 27G from being accepted by the conveying device 2 (if it is not accepted, paper trouble will occur in the next roller feeding), when the leading paper enters the above prohibited area, New roller feeding is prohibited.

In the paper feed clutch on routine 52 (Fig. 3j), 1 MI
& Check the clutch on request flag (10
6). With this, roller feeding (each sheet of paper) is still required (paper feeding from the cassette is required), so check whether or not roller feeding is possible by setting the paper feed clutch prohibition flag. Determination is made by checking (107). If there is no paper feed clutch on request flag, there is no need for roller feeding, and if there is a paper feed clutch prohibition flag, roller feeding is prohibited, so the process proceeds to the transport latch off routine 5°3. If the paper feed clutch on request flag is present and the paper feed clutch prohibition flag is not present, roller feeding is required and roller feeding is possible, so check which cassette is specified for paper feeding.108, 115, 1
17), If the intermediate cassette l is specified, the clutch 28CL for driving the roller 28 is set to be energized 109), If the third cassette 26C is specified, the clutch 26CL for driving the roller 26 is to be set to be energized 116) ), if the fourth cassette 27C is designated, the roller 27 and the driving clutch 27CL are energized (118). When the first or second cassette 26G or 27G is designated, the process proceeds to step 53 since paper feeding control similar to conventional paper feeding is performed in the copy mode 17. Now, the paper feed cassette is intermediate cassette 1. The third cassette 26C or the fourth cassette 27G, and the paper feed roller clutch 28CL.

When 26CL or 27CL is biased, the clutch 2CL that drives the intermediate conveyance device 2 is biased (11
0) Set the paper feed to the registration roller 3, and update the content of the paper feed counter to a number smaller by 1 to represent feeding of one sheet of paper (111).

Then, in order to allocate counter A to tracking the feeding position of the paper that has started roller feeding, the contents of counter B are transferred to counter C (112), the contents of counter A are transferred to counter B (l l 3), The contents of counter A are cleared (114). That is, the counter A is set to count up from 0.

The process then proceeds to a transport latch-off routine 53.

In the conveyance latch-off routine 53 (the third figure), first the paper sensor 3 provided on the registration roller 3 is activated.
Check whether or not a detects paper.119)
, if it is detecting paper, it checks the pulse counter S set flag to determine if it has changed from non-detection to detection (120). If this flag is not present, it will start from non-detection and then change to detection, so clear the pulse counter S (set the count to start from 0) and set it to 1.
21), set the pulse counter S set flag (
122). This means that the counter S starts counting the amount of paper feed after the leading edge of the paper reaches the sensor 3a. Then, the process advances to a paper feed waiting routine 57. When proceeding to the transport latch off routine 53, if the pulse counter S set flag is present (the paper has already reached the third registration roller), the contents of the pulse counter S are checked and if it is 20 or more. Then, the leading edge of the paper hits the registration roller 3 and is bent as desired, so the conveyance latch 2CL is deenergized to stop the intermediate conveyance bag W2 (124), and the process proceeds to the copy preprocessing routine 31.

If the content of the counter S is less than 20 in step 123, the process proceeds to the copy preprocessing routine 31 with the conveying latch 2CL kept in the energized state in order to wait for a little paper feeding. In addition,
When the transport latch off routine 53 is entered, the sensor 3
If a is a paper defect detected, the pulse counter S set flag indicating that paper is detected is cleared (125) and the process proceeds to the copy preprocessing routine 31.

In the copy pre-processing routine 31 (Fig. 3e), whether or not the pre-cleaning has ended is determined by referring to whether or not the pre-cleaning time limit timer set in the pre-cleaning process 55, which will be explained next, has timed out. Judgment 54
), the preprocessing cleaning 55 is executed if it has not been completed (the timer has not been set or the time has not expired).

In this, set the timer if it is not set,
If set, the process advances to the next step 56.

In step 56, the paper feed OK flag (second cassette 25C
Intermediate transport device i! which can be used in the same way as roller feeding. This is a flag indicating that there is paper closer to the registration roller 3 than the position at position 2, and is set in a paper feed wait routine 57 to be described later).

If there is a paper feed OK flag, pre-cleaning completion check 5
Proceed to step 8. If there is no paper feeding OK flag, the process advances to a paper feeding wait routine 57. In the paper feed waiting routine 57.

As shown in Figure 3Q, check which cassette is set for paper feed.126.130.134
), if it is intermediate cassette 1, it starts feeding paper from cassette 1, starts counting drum synchronization pulses, and then counts 431 (equivalent to the paper feeding position of second cassette 25C as seen from registration roller 3). position)
127-129),
If the paper feeding OK flag has been reached (138), the process proceeds to pre-cleaning completion check (58: Fig. 3e).

If the cassette set to feed paper is the third cassette 26G, the paper is fed out from the cassette 26G and the position at which 106 is counted after the drum synchronization pulse count starts (
Check whether the offset has reached the same position as the paper feeding position of the second cassette 25C when viewed from the registration roller 3 (131 to 133), and if so, set the paper feeding OK flag (138), and perform pre-cleaning. Completion check (58
: Proceed to Figure 3e). If the force set for paper feeding is the fourth cassette 27C, the paper is fed out from the cassette 27G and the count of drum synchronization pulses is started.
135 to 137), and if so, set the paper feeding OK flag 138 ), Proceed to pre-cleaning completion check (58: Figure 3e). If the cassette set to feed paper is the first or second cassette 24G or 25C, no matter what time you feed the paper, the photoconductor Since the paper can be fed to the drum 17 in synchronization with the latent image at a predetermined timing, it is recommended to set the paper feeding OK flag (138) and the pre-cleaning completion check (58: 3rd e).
Proceed to Figure 6) In the pre-cleaning end check 58, it is checked whether the pre-cleaning timer set in the pre-cleaning process 55 has timed out. If the time has not elapsed, proceed to the pre-copy mode completion check 32 in the pre-copy mode 14 (Figure 3b).If the time has elapsed, check the paper feeding OK flag 59), and if there is, the process will proceed to the pre-copy mode completion check 32 of the pre-copy mode 14 (Figure 3b). Since the paper can be sent to the registration roller 3 at any time, set the copy pre-processing completion flag 60), clear the pulse counter D (set the count up from 0) L (61), and copy in the pre-copy mode 14 (Figure 3b). Proceed to pre-mode completion check 32. If there is no paper feeding OK flag, the process proceeds to pre-copy mode completion check 32 without setting a completion flag.

Therefore, there is a paper feeding OK flag (the paper is at the same position as when feeding the paper from the second cassette 25C to the intermediate conveyance device!2, or at a position closer to the registration roller 3).
, because when you finish the pre-cleaning, you have completed the pre-copy mode.

Check 32 is YES, and the process proceeds to copy mode 17.

As already explained, in addition to the paper feed control routine 1 in the copy mode 17 that feeds paper from the first or second cassette 24C or 25C as in the conventional case, the above-mentioned paper feed control routine 30 is also included. include. Therefore, when paper feeding is started in the pre-copy mode 14 and the process proceeds to the copy mode 17, the paper feeding control started in the pre-copy mode 14 is similarly continuously executed in the copy mode 17. Therefore, intermediate cassette 1. 3rd cassette 26C
Alternatively, regarding only the paper feed control when the fourth cassette 27G is designated as paper feed, it is understood that the paper feed control routine shown in FIG. 3d is continuously executed even in the copy mode 17. It will be easier to understand the overall paper feed control.

In addition to the paper feed control routine 30 similar to the paper feed control routine 30 included in the copy mode 17, the copy mode 17 also includes a registration clutch on routine 140 shown in FIG. Other processing is the same as in the conventional copy mode.

To explain the registration clutch on routine 140 (Fig. 3m), in this routine, when the timing to drive the registration roller 3 in the copy mode (17) comes (141)
, energize and set the clutch 3CL that connects the registration roller 3 to the drum drive power system (142), intermediate conveyance device!
Clutch 2CL connecting 2 to the drum drive power system is energized (143), and the paper feed clutch prohibition flag is cleared (144). Note that when the registration roller 3 is stopped, the clutch 2CL is deenergized.

The outline of the paper feeding operation brought about by the paper feeding control operation explained above is as follows:
A case will be described in which A5 paper is stored in the intermediate cassette in a horizontal feeding position and the number of copies per copy is set to 5. In this case, the relationship between the position of the paper fed out from the cassette 1 in the intermediate conveying device i2 and the count contents of the counters A, B, and C is shown in FIG.

When the print key is pressed, the main motor (drum drive power system) is energized (26) in the pre-copy mode (14).
The photosensitive drum 17 is rotated at a constant speed. This generates a drum sync pulse. Next, start the drum synchronous pulse count of the pulse counter A (36), update the contents of the paper feed counter to a number 1 smaller (38), drive the intermediate conveyance bag [2] (37), and drive the paper feed roller 28. (4
0) Feed out the paper from cassette 1. Next, every time one drum synchronization pulse appears, counter A is incremented by 1 66), waits until the content of counter A reaches 80 (70), and when it reaches 80, the paper feed roller 28 is stopped 71)
, wait for the contents of counter A to become 275 or more (79
). When it reaches 275, the next paper feed clutch on request flag is set (92), and the paper feed roller 28 is driven (10
9) Feed out the second sheet of paper and set the content of the paper feed counter to 1.
Update it to a smaller value (111), move the contents of counter A to counter B, clear counter A, and start counting up the drum synchronization pulse again (113, 114).
). When the content of counter A reaches 80, the paper feed roller 28 is stopped (70), and when the content of counter B reaches 535, feeding of new paper from cassette 1 is prohibited (95,10).
5) When the sensor 3a detects the first sheet of paper (119
), then after 20 pulse counts intermediate conveyance device f!
Stop 2. When the registration roller 3 is driven (14
1, 142), drive the intermediate conveyance device 2 143, 14
4) Drive the paper feed roller 28 (109) to feed the third sheet of paper and update the content of the paper feed counter to a number smaller by 111) , set the content of counter B to counter C and the content of counter A is transferred to counter B, counter A is cleared, and counting of drum synchronization pulses is started (11
2-114). When the content of counter A reaches 80, the paper feed roller 28 is stopped, and when the content of counter B reaches 535, feeding of a new paper from the cassette 1 is prohibited, and the sensor 3a picks up the second paper. When detected (119), the intermediate conveyance device 112 is stopped after 20 pulses have been counted. When the registration roller 3 is driven (141, 14
2) , drive the intermediate conveyance device 12 L (t 43.14
4), MMko.

109) to feed out the fourth sheet of paper and update the content of the paper feed counter to a number smaller by 111).
Transfer the contents of counter B to counter C.

Transfer the contents of counter A to counter B, clear counter A, and start counting drum synchronization pulses (
112 to 114), and when the content of counter A reaches 80, the paper feed roller 28 is stopped, and the content of counter B becomes 535.
When this happens, feeding out new paper from cassette 1 is prohibited, and when sensor 3a detects the third paper (119)
, and then after 20 pulses have been counted, the intermediate conveyance device 2 is stopped. When the registration roller 3 is driven (141°1
42), intermediate conveyance device i! Drive 2 143°144
), the paper feed roller 28 is driven (109), the fifth sheet is fed out, and the content of the paper feed counter is updated to a number smaller by 1. Transfer the contents of counter B to counter C and the contents of counter A to counter B, clear counter A, and start counting drum synchronization pulses (112 to 11).
4). When the content of counter A reaches 80, the paper feed roller 28 is stopped, and when the content of counter B reaches 535, feeding of new paper from the cassette 1 is prohibited.

When the sensor 3a detects the fourth sheet of paper (119), the intermediate conveyance device 2 is stopped after 20 pulses have been counted. When the registration roller 3 is driven (141, 142
), drives the intermediate conveyance device 2 (143, 144),
Since the content of the paper feed counter is 0, proceed to step 7.
Go from 6 to 51.

The next paper feed clutch on request flag is not set, and therefore steps 109 to 114 are not executed. In other words, the paper feed roller 28 is not driven. When the sensor 3a detects the fifth sheet of paper (119), the intermediate conveyance device 2 is stopped after 20 pulses have been counted. When the registration roller 3 is driven (141, 142), the intermediate conveyance device i! 2
to drive.

As described above, the set number of sheets of paper to be copied is delivered to the intermediate conveyance device 2 by the paper feed roller 28, the intermediate conveyance bag [2 is sent to the registration rollers 3, and the registration rollers 3 are sent to the transfer section. The operation when the other cassette 26C or 27C is designated for paper feeding is also the same as the paper feeding from the cassette l described above.

However, there are differences in the distance between the cassette and the intermediate transport device.

In response to the difference in distance between the registration roller and the cassette,
The count values that determine the roller stop timing, etc. are different.

In the embodiment described above, the leading edge position of the paper in the intermediate conveyance device 2 is tracked by counters A, B, and C (program counters), and the paper fed out from the cassette is transferred to the intermediate conveyance device i! In step 2, determine the timing at which the receiver is inserted, and the first paper is the prohibited area (range L in Figure 4).
When the paper is entered, it is prohibited to feed out new paper.

In another embodiment of the invention, the intermediate transport device 2
Equipped with a paper sensor at the entrance and the boundary of the prohibited area,
Based on the paper detection signals of these paper sensors, intermediate,
Transport bag! ! ! With the acceptance of paper to 2.

It is determined whether the paper enters the prohibited area, and otherwise the paper is fed out from the cassette and the paper feeding of the intermediate conveying device 2 is controlled using the same logic as in the above embodiment. 3 shown by the two-dot chain line in Figure 1
0 is a paper sensor for detecting acceptance of paper fed out from the intermediate cassette 1 into the intermediate conveyance device 2;
29 is the intermediate conveyance device! This is a paper sensor for detecting that the paper being fed in step 2 has entered the prohibited area. FIG. 5 shows control of feeding out paper from the intermediate cassette 1 using these sensors 29 and 30. In this case, the paper feed counter increments by one count each time a sheet of paper is fed into the intermediate transport bag w2. Further, m is a value that is 1 larger than the maximum number of sheets of paper that can be sent simultaneously in the intermediate transport bag [2. Therefore, when the content of the paper feed counter is less than m (151), the intermediate conveyance device 2 is not driven when the sensor 29 does not detect paper (153) (ts4), and the sensor 30 does not detect paper. When the paper feed roller 28 is driven (158) and the sensor 3o detects paper, the paper feed roller 28 is stopped (160), a paper detection flag is set (162), and the paper feed counter is counted up by one. Thereafter, when the sensor 3o detects paper failure, the paper detection flag is cleared (159). In this way, after the content of the paper feed counter reaches the maximum number of sheets +1, that is, m, the intermediate conveyance device 2 is driven only while the registration roller 3 is being driven, and cassette paper feeding is enabled.

■Effects According to the invention explained above, the paper feed tray (1°26C,
Paper feeding from 27C) to the recording feed roller (3) is performed at a cycle shorter than the copy repetition cycle, and the paper waits at the recording feed roller section, so the paper feed is the same as the conventional copy repetition cycle. Unlike when paper is fed out from a paper feed table at regular intervals, the paper is less likely to arrive at the recording feed roller late due to slip or skew, resulting in fewer errors in feeding the recording roller or misaligned recorded images.

Further, in the conventional case where the drive timing of the recording feed roller is set late in anticipation of the occurrence of feed slip or skew, when there is little paper slip, troubles such as paper jams occur less. Not only that, but the intermediate conveying devices can be collectively driven and controlled by one clutch or motor.

The structure of the paper conveyance system is simplified, and the drive control of the mechanism is also simplified.

[Brief explanation of the drawing]

FIG. 1 is a block diagram schematically showing the mechanical structure of an embodiment of the present invention, and FIG. 2 is a block diagram schematically showing the structure of an electrical control system of the embodiment. 3a is a flowchart showing an overview of the control operation of the microprocessor 58 shown in FIG. 2, FIG. 3b is a flowchart showing an outline of the contents of the pre-copy mode (14) shown in FIG. 3a, and FIG. The initial paper feed routine shown (
27) Flowchart showing details of 3d and 3b
FIG. 3E is a flowchart showing the outline of the paper feed control routine (30) shown in FIG. 3B, FIG. 3F is a flowchart showing the contents of the copy preprocessing routine (31) shown in FIG. (48), FIG. 3g is a flowchart showing the contents of the paper feed clutch off routine (49) shown in FIG. 3d, and FIG. 3h is a flowchart showing the next paper feed ON routine (49) shown in FIG.
50) Flowchart showing the contents of 3d.
IJ! FIG. 3j is a flowchart showing the contents of the paper feed clutch inhibit routine (51) shown in FIG. 3D;
Third, the transport latch-off routine (shown in Figure 3d)
53), the flowchart showing the contents of 3Q is 3e
FIG. 3m is a flowchart showing the contents of the paper feed waiting routine (57) shown in FIG.
Resist clutch on routine (140) included in 7)
) is a flowchart showing the contents of the process. Fig. 4 shows when A5 size paper is fed out from the intermediate cassette l in a horizontal position. Intermediate conveyance device! ! 2 is a time chart showing the relationship between the position of the paper and the count value that tracks it. FIG. 5 is a flowchart showing the paper feed control operation of another embodiment of the present invention. Patent Applicant: Ricoh Co., Ltd. and 1 other person, Day 3d, Port 3e, Port 3f, Port No. 39, 1c13h, Figure 31. 3rd time

Claims (7)

[Claims] (1) A recording feed roller that sends paper to the recording section, a paper feed tray on which the paper is placed, an intermediate conveyance device that is located between the paper feed tray and the recording feed roller and sends the paper fed out from the paper feed tray to the recording feed roller;
and a paper feeding control device that controls feeding out of paper from the paper feeding tray and feeding bias of the intermediate conveyance device: feeding out the paper from the paper feeding tray in accordance with a paper feeding instruction; The paper is fed out at a predetermined interval, the intermediate conveyance device is fed and energized, and the paper is sent to the recording feed roller. When the recording feed roller is in the driving state to feed the paper to the recording section, the intermediate conveyance device is fed and energized and the paper is fed from the paper feed tray. continues to feed the paper at predetermined intervals, and when the leading paper on the intermediate conveyance device is in the area in front of the recording feed roller by a predetermined distance L, which is slightly longer than the distance Ld between the paper feed table and the intermediate conveyance device, the paper is fed out at a predetermined interval. A paper feed conveyance control device characterized by comprising the paper feed control means that stops feeding and stops the intermediate conveyance device after the leading paper reaches the record feed roller when the recording feed roller stops. (2) The paper feed tray includes one of the plurality of recording paper cassettes.
The paper feeding and conveyance control device according to claim 1, wherein the recording paper cassette is located at a position farther from the recording feeding roller and is different from the recording paper cassette closest to the recording feeding roller. (3) The paper feed tray is a paper feed cassette for double-sided recording that stores recording paper recorded on one side.
1) The paper feed conveyance control device described in item 1). (4) Set the paper feed interval from the recording feed roller to the recording unit to t_
2, the time required for the paper to reach the intermediate conveyance device from the paper feed tray is t_3, and the set margin time is t_4, then the paper feed control means moves the paper feed tray at a repeating interval of t_1=t_2−(t_3+t_4). A paper feed conveyance control device according to claim (1), which feeds out paper. (5) The paper feed conveyance control device according to claim (4), wherein t_3 is the time during which the paper fed out from the paper feed tray advances by Ld, and t_3+t_4 is the time during which the paper advances by L in the intermediate conveyance device. (6) The paper feeding and conveyance control device according to claim (4), wherein t_1 to t_4 are based on count values of pulses synchronized with constant speed rotation of the image forming means of the recording section. (7) The paper feeding control means counts the pulses to measure t_1 to t_4 while the intermediate transport device is in the feeding state, and stops the counting when the intermediate transport device stops. 6) Paper feed conveyance control device described in section 6).