JPS6313182B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides a first document exposure mode in which a document on a document table is exposed by a reciprocating optical member, and a first document exposure mode in which a sheet document is exposed while being transported by a sheet document transport mechanism and is ejected without stopping the sheet. The present invention relates to an image forming apparatus having two document exposure modes. In order to properly form an image corresponding to the original image exposed in a copying machine on a recording material being conveyed, the transportation of the recording material and the original exposure operation are executed in association with each other. However, in a copying machine equipped with a plurality of copying modes, it may be necessary to vary the image forming operation depending on the mode in which it is to be executed. That is, a first document exposure mode in which a document on a document table is exposed by a reciprocating optical member, and a second document exposure mode in which a sheet document is exposed while being transported by a sheet document transport mechanism and is ejected without stopping the sheet. In an image forming apparatus equipped with an original exposure mode, in order to perform both different original exposure operations at high speed in image formation in the first and second original exposure modes, separate standards are set for each original exposure mode. It was necessary to provide signal generating means and to execute operation control for each mode using reference signals corresponding to each mode. The present invention has been made in view of the above points, and includes a first document exposure mode in which a document on a document table is exposed by a reciprocating optical member, and a sheet document conveying mechanism that transports a sheet document while conveying the sheet document. In an image forming apparatus equipped with a second original exposure mode in which the sheet is exposed and ejected without stopping the sheet, different original exposure operations in image forming operations in the first and second original exposure modes are performed using a common reference signal. The purpose is to control the image forming operation in both the first and second document exposure modes at high speed. In an image forming apparatus equipped with a second original exposure mode and a second original exposure mode in which the sheet original is exposed while being transported by a sheet original transport mechanism and ejected without stopping the sheet, a desired original exposure mode can be selected. a selection means for selecting, a transport means for transporting the recording material, and an image corresponding to the original image exposed according to the original exposure mode selected by the selection means, which is transported to an image forming position by the transport means. A process means for forming on a recording material, a detection means for detecting the trailing edge of the recording material transported by the transport means, and a mode signal indicating an original exposure mode selected by the selection means and from the detection means. control means for controlling the document exposure operation based on the trailing edge detection signal of the recording material from the detection means; Based on the trailing edge detection signal, the optical member that is moving forward for document exposure is moved backward to control the termination of the document exposure operation in progress, and in the second document exposure mode, the first document exposure mode is controlled. In the original exposure mode, the next original is conveyed by the original transport mechanism based on the trailing edge detection signal of the recording material from the detection means, which is used as a reference for end control of the original exposure operation being executed, and the next original exposure operation is started. An image forming apparatus that executes start control is provided. With this configuration, different document exposure operations in image forming operations in the first and second document exposure modes can be performed using the trailing edge detection signal of the recording material without providing separate reference signal generation means for each document exposure mode. can be controlled using a reference signal common to both modes, and in the first document exposure mode, the optical member that is moving forward to expose the document can be returned without moving forward over an unnecessary distance. Therefore, the forward movement of the optical member for exposing the next document can be quickly started, and therefore, the image forming operation in the first document exposure mode can be executed at high speed, and on the other hand, In the second document exposure mode, the next document is transported by the document transport mechanism following the ongoing image forming operation, so that the next document exposure can be started quickly.
Similar to the first original exposure mode, it is possible to perform the image forming operation in the second original exposure mode at high speed. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings together with an overview of the copying machine. In FIG. 1, a document 1 is placed on a document table glass 2 that constitutes a document placement surface on the top surface of the machine case. Then, the illumination lamp 3, a first mirror 4 that moves together with this, and 1/2 of this first mirror 4.
a second mirror 5, a switching mirror 6, a lens 7, a fixed mirror 8, which move in the same direction at a moving speed of
The slit is exposed by an optical system consisting of the following, and the image is formed onto the drum 9. The surface of the drum 9 is a photosensitive surface, and is charged by a charger 10. Subsequently, when reaching the exposure section 11, the photoreceptor is exposed to the original image and at the same time is subjected to static elimination by the static eliminator 12. Next, an electrostatic latent image is formed on the surface of the drum (photoreceptor) by full exposure by the full surface exposure lamp 13 and enters the developing device 14 . Development is performed by a developing roller 15. Thereafter, the post charger 16 squeezes out the surplus developer. Next, the image on the drum 9 is transferred by the transfer charger 17 onto the copy paper 20 sent out from the feeding section 18 or 19. The copy material that has been transferred is separated from the drum 9 by a separation section 21, guided to a fixing section 22, fixed thereon, and then discharged onto a tray 24 by a discharge roller 23. On the other hand, the remaining toner on the drum surface (photosensitive surface) is cleaned by the blade 25 pressed against it, and the next cycle can be repeated again. When copying a thick original, the switching mirror 6 is in the state shown by the two-dot chain line. When the switching mirror 6 is moved to the solid line position and the movable mirrors 4 and 5 are moved to the right end (solid line position), the automatic sheet document feeding device 26 can be used. In this case, the original passing through the exposure section 30 is illuminated by the lamp 3, and its image is formed on the drum 9 by the switching mirror 6, the lens 7, and the fixed mirror 8. This lamp 3 is the same lamp used for thick originals. (Described later) The sheet document 28 stacked on the document stacking table 27 of the automatic sheet document feeder 26 is separated by a separating roller 29 into which the topmost sheet is separated, and then a series of feed rollers 31, 32, 33, 34, the document is conveyed to the document tray 35 via the exposure section 30, and is discharged. This automatic sheet document feeding device allows automatic continuous feeding of sheet documents. Furthermore, by setting the transport speed of the exposure section transport systems 31 to 34 to be somewhat faster than the separation transport speed of the separation system 29, it is possible to create a distance between the first and second sheet documents during transport. It becomes easy to detect the leading edge or trailing edge of the document. FIG. 1 shows the state in which either the main cassette 73 or the sub cassette 74 is used. By switching the button, either the upper or lower paper feed roller 53 can be selected to operate. FIG. 2 shows a state in which a manual cassette 75 is used. The cassette receiver 80 is pivotally connected to a shaft 76 fixed to the main body. The manual feed cassette 75 is slidably attached to the cassette receiver 77, and one end of the manual feed cassette 75 is attached to the link 7.
8 to a shaft 79 which is pivotally supported on the main body. The shaft 79 can be swung by a motor, and its position can be selected by switching buttons. Further, as shown in FIG. 2, a paper detection element (lamp, light receiving element 103) is placed in the copy paper path corresponding to the distance l between the transfer device and the exposure position. Then, the optical system is reversed by the rear end of the paper. Note that the control will be described later. The guidance of the optical system and the illumination section will be explained with reference to FIGS. 3 to 7. The first mirror 4 is fixed to a base member 36 that holds it. This platform member is connected to a linear guide inner member 37, which is manufactured by the trade name Akyuride. As shown in FIG. 4, this Akyuride has a structure in which a large number of rollers 40, which are held by retainers 39 so as not to fall off, are arranged in two linear spaces formed by grooves in each of the inner member 37 and outer member 38. The inner member 37 is linearly guided with respect to the outer member 38. The space in which the rollers 40 are arranged is slightly narrower than the outer diameter of the rollers 40, so that a preload is applied to the rollers 40.
Therefore, the outer member 38 and the inner member 37 are guided without play. As shown in FIG. 5, the outer member 38 covers the stroke of the first mirror 4 and is attached to the machine frame (not shown) by a support member 41. Although the inner member 37 has only the same length as the attachment part of the base member 36 of the first mirror, it is guided to the other end while moving over a large number of rollers 40. A roller 42 is provided at the front end of the base member and rests on a rail 43 fixed to the main body. The second mirror 5 is fixed to its own support member 44, which in turn is fixed to the inner member 37 of the acrylide fixed downward. A conventional linear guide is schematically shown in FIG. In this system, the mirror supports 36 and 44 are linearly guided by round bar-shaped rails 45 fixed at both ends. With this method, the rail 45 can only be supported at both ends, resulting in low rigidity. In order to prevent the receiving parts of the mirror support stand from interfering with each other, the span l of the receiving part of the first mirror support stand is particularly shortened. Because it is difficult to avoid play between the round bar and the sliding bearing that slides on the round bar, we are able to manufacture mirrors with high precision.
Moreover, it cannot be moved stably. According to the present invention, any part of "Akyuride" can be connected to the main body (it can be firmly fixed), and "Akyuride" itself has large dimensions and a large section modulus.
Since the supporting part of the Akiuride and the receiving parts of the first and second mirror supporting stands do not interfere with each other, the receiving part span l of the supporting stand can be made sufficiently large.As mentioned above, there is no play between the inner member and the outer member. Because there is no burr, it is possible to perform stable reciprocating motion with extremely high precision. In FIG. 3, the position indicated by the solid line is the home position, and as described above, the first and second mirrors 4 and 5 move to the right to scan the original, and return to the home position by the force of the spring 45. do. When the button of the automatic sheet document feeder is pressed, the clutch motor moves it to the position indicated by the dashed line at the right end and locks there (described later). At this time, the lamp 3 moves to a position where it can illuminate the sheet document. Details of this part will be explained with reference to FIGS. 6 and 7. FIG. 6 shows a state in which an original on the original platen glass 2 is being scanned. A support arm 46 fixed to the mirror support member 36 has a support shaft 47 fixed thereto, and the illumination lamp 3, reflector 48, and support follower 49 are integrally constructed so as to be able to rotate around this support arm 46. A roller 50 is attached to one end of the support follower 49 so as to operate as a follower. FIG. 6 shows details of the vicinity of the first mirror 4 during copying of a thick original. FIG. 7 shows details of the vicinity of the illumination section when the automatic sheet document feeder is operating.
When the first mirror 4 and the second mirror 5 move to the right end, the first mirror and the second mirror approach each other due to the speed difference. A cam plate 51 is fixed to the support member 44 of the second mirror, and the rollers 50 follow the cam surface of the cam plate 51, so that the illumination lamp 3 and the reflector 48 are used to expose the sheet original as shown in FIG. 30. Details of the paper feeding portion will be explained with reference to FIGS. 9, 10, 11, and 12. The paper feed roller 53 is fixed to its shaft 54, and the shaft is supported by an arm 55. A rotation shaft 56 is fixed to this arm 55,
This shaft 56 is pivotally supported by the main body frame. Therefore, the paper feed roller 53 can swing around the shaft 56. A spring 57 is applied to the arm 55, and the arm 55 is pulled upward. The shaft 54 has
There is a follower roller 58, which operates as a follower of the cam 59. The cam 59 is controlled by a one-turn clutch with a temporary stop. Next, this will be explained with reference to FIGS. 11 and 12. The cam shaft 60 passes through a frame 61 and is pivotally supported by this. The input to this camshaft is input from the motor through the belt 62 and into the pulley 63. The body ₆₃₁ of the pulley 63, the clutch drum 64 fixed to the shaft 60, the clutch spring 65, and the stop ring 66.
The spring clutch consisting of is controlled by a solenoid 67. When the solenoid 67 is not suctioning, the lever ₆₈ is located at the position shown by the solid line in FIG. It's summery. When solenoid 67 suctions,
When the lever 68 reaches a position 68' indicated by a dashed line, it is disengaged from the projection ₆₆₁ and the clutch is engaged, causing the cam 59 to rotate. However, when the clutch is rotated approximately 180 degrees, another projection ₆₆₂ engages with the lever 68', and the clutch is disengaged again. At this time, the paper feed roller 53 is pushed down by the cam 59 and is at the position indicated by the dashed line 53' in FIG. When the pressed down state is reached, the friction pulley 69 (Fig. 10) fixed to one end of the paper feed roller shaft 54 and the constantly driven capstan 70 (Figs. 9 and 10) come into contact with each other to feed the paper. The roller 53 will be driven. When the suction of the solenoid 67 is released, the protrusion 66
₂ and the lever are disengaged, the clutch becomes engaged again, and when it rotates about 180 degrees, it returns to the state shown by the solid line in FIG. 11, and the clutch becomes disengaged. The clutch spring 65 is hooked at one end to the stop ring 66 and at the other end to the clutch drum 64, so that the relative relationship between the protrusions 66 ₁ and 66 ₂ of the stop ring 66 and the cam 59 will not shift due to repeated clutch operations. It's getting old. If the cam is temporarily stopped in the middle in this way, the time during which the cam is pressed down can be controlled by the suction time of the solenoid, increasing the degree of freedom in design, which is useful. A conventional example of a cam control method for causing this temporary stop is shown in FIG. In Fig. 13, 66 is a stop ring, 66 ₁ and 66 ₂ are recesses for hanging the stop ring and stopping it.
The levers b and c are for engaging the respective recesses and rotate about the axis d. Lever a with dowel a' also has a solenoid 67 centered around axis d.
and controls two levers b and c. Although a detailed explanation of the operation will be omitted, the present invention is clearly simpler than this method, and therefore has higher reliability and lower cost. In the conventional example, the balance of two springs and the accuracy (tolerance) of some parts
The reliability is low and the cost is high due to the overlap of the parts and the complicated movement of each part relative to each other. The paper ejected from the cassettes 73, 74, and 75 is fed as shown in the two-dot chain line P in Fig. 9 depending on the ejecting direction, the stiffness of the paper, its own weight, etc., but in order to ensure accurate timing with the machine. register roller 52
(it is stopped at this time), and after making a loop like P', register roller 5
2 starts rotating and sends out the next one. If this conventional method was used, loops like P' could not be created properly and jams could occur. If you look closely at this, you will notice that the loop is reversed, as shown by P″.
Paper jams occur between the cassette 75 and the guide plate 71. This is because when the state of the paper changes from P to P', the space between the paper and the guide plate 71 tries to expand rapidly, but if air is not properly supplied to this area, atmospheric pressure will cause the paper to expand. It turns out that this remains pressed at the position of P and becomes like this. Therefore, as shown in FIG.
1. A large number of holes 71 ₁ and 72 ₁ for ventilation are bored in the guide plate 72 (the guide plate of the lower feeding section). Note that the holes 71 and 72 may be provided in either the upper or lower guide plate. With this treatment,
There were no troubles like those shown in P″.First
In Figure 4, the elongated holes are widened toward the end to prevent the paper from getting stuck, but the same effect can be obtained by providing a large number of round holes. Process control in the present invention will be explained.
A feature of the present invention is that by controlling the operation of process means such as document feeding from the movement position after the start of feeding of the transfer paper, high-speed continuous copying is possible regardless of the size of the transfer material. By reading out the memory contents in which the sheet mode process timing is programmed and controlling the process, the process timing does not change even if a command related to the other mode is issued after the process starts in one mode. In program control, it is possible to effectively use fewer output lines by counting signals from load control signal lines and controlling the operation of multiple control loads, and in program control, it is an input means by specifying the number of copies and detecting the copy state. (Operation input section) Fig. 15 shows a copying apparatus according to the present invention, by effectively using a small number of input signal lines and reducing power consumption by connecting input signal lines with output signal lines under program control. The operation panel for performing the desired operation is shown. 120 is a display section showing the paper size in the cassette;
121 is a display section for displaying the selected cassette; 122 is a switch for selecting a manual feed cassette; 1
23 is a switch for selecting the upper cassette, 124 is a switch for selecting the lower cassette, 125 is a display for displaying the set number of copies and the number of copies, 126 is a numeric keypad for setting the number of copies, and 127 is for correcting the set number. Clear key to use, 12
8W is a weight, 128P is out of paper, 128L is out of liquid, 128J is a display unit that displays paper jams, etc., 129 is a stop button to temporarily stop copying, 130 is a start button for book copying, 1
31 is a start button for automatically feeding sheet originals. (Process Sequence) FIGS. 16 to 18 are sequence flow diagrams from power-on to completion of copying of the copying apparatus according to the present invention. 19 and 20 are time charts showing the operation timing of each process means. The basis for forming a timing signal for executing the following process after power-on and a copy command (key entry cycle described below) is a clock signal of one pulse every 1 mm at a process speed (drum rotation speed of 100 mm/sec). (Cassette Check) Although the basic process progresses as described above, the actual operation of the apparatus will be explained based on this process with reference to FIGS. 26 to 29. When the main switch is turned on, the fuser heater is energized and copying does not start during the wait time until the temperature reaches the set value. After the wait is released, if there is paper (transfer paper) and toner, the state becomes ready for copying. The cassettes have a three-tier configuration, and if you fill the upper and lower cassettes with frequently used specified sizes, you can save two cassettes without having to change the cassettes by hand.
It is possible to copy types. Furthermore, a manual cassette mechanism is provided to allow transfer paper of non-standard sizes. This three-stage cassette has push button switch 12.
2,123,124 can be selected. Since the upper cassette and the manual cassette are fed by the same paper feeding device, the unused cassette is positioned so as not to interfere with paper feeding. This state is detected by a microswitch 100 linked to the cassette moving mechanism. Furthermore, this mechanism is operated by a motor 108, which is controlled by the state of the microswitch. In FIG. 2, reference numerals 150 and 151 indicate lamps and light receiving elements for detecting paper in each cassette. (Book Mode) The process sequence for copying in book mode will be explained with reference to the flow shown in FIG. 16 and the time chart shown in FIG. 21. When the copy button 130 is pressed, copying starts. First, the drum drive motor 112 is turned on, and at the same time as the photosensitive drum starts rotating, pre-charging and pre-exposure are started to reduce potential unevenness of the photosensitive member in advance. When the aforementioned clock counts 300, the primary charger 10,
The AC static eliminator 12, full-surface exposure lamp 13, liquid squeezing charger 16, transfer charger 17, and blank exposure lamp 102 are turned on. When the clock counts 120, the optical system advance clutch 109 is turned on and the optical system advances. Furthermore, the registration clutch 110 is turned on and the registration roller 52 is rotated. Furthermore, when the clock counts 6 pulses, the paper feed plunger 113 is turned on and the paper feed roller 5, which is constantly rotating, is turned on.
3 is lowered and the transfer paper is sent out from the cassettes 73-75. Further, the document exposure lamp 3 is turned on and begins to move together with the optical systems 4 and 5 while illuminating the surface of the document. Also, the blank exposure 102 that was lit is turned off. When the transfer paper 20 is fed, a detector 103 detects whether it has been fed normally. Clock 60 after paper feeding
After counting the pulses, paper is detected, and if the paper has not arrived, a paper feeding error is displayed. In this case, 111 for heater control and transport drive
The motor continues to operate, but all other drive systems are turned off. When using the upper 74 and lower 73 cassettes, after removing the paper that was misfed,
Press the start button again to enter copy mode.
When the cassette is the manual feed cassette 75, the remaining amount of paper is not detected, so the paper feeding error display is activated when there is no transfer paper. This causes the cassette moving motor to operate and pull the cassette out. When the cassette motor 108 reaches the normal position, the microswitch 100 operates and issues a signal to stop the cassette motor 108. When the transfer paper is inserted and the start button is pressed again, the cassette motor is activated and the cassette is moved into the machine. When the cassette is in the normal position, the micro switch 100 is activated again and outputs a signal to stop the cassette motor. Enter copy state. If the transfer paper reaches 60 clock pulses, a new 50 clock pulses will be counted from the time the transfer paper reaches 60 clock pulses.
After counting the pulses, the registration clutch 110 is turned off to stop the rotation of the registration roller 52, and the leading edge of the transfer paper is brought into contact with the roller to temporarily stop it. After this, when the optical system passes a predetermined position, the registration signal RS issued by the switch 116 turns on the registration clutch, the registration roller starts rotating, and the transfer paper passes through the registration roller and moves toward the drum. Sent. The timing of this registration signal is such that the leading edge of the image on the drum coincides with the leading edge of the transfer paper. When the registration signal comes, the paper feed plunger 113
is also turned off, and the paper feed roller stops feeding paper. When the transfer paper passes the detector, the document exposure lamp 3 is turned off, and the optical system advance clutch 109 is also turned off, so that the optical system becomes free and is pulled back to the home position of the optical system by the force of the spring. It can be done. When the optical system moves backward, the blank exposure lamp 102 is turned on. At this time, the set number of sheets is subtracted by 1. If after a jam reset, the first copy will not be reduced by -1 to compensate for the loss of one jammed copy. As a result, the remaining number of copies is checked and if it is 0, the process proceeds to the end mode. If not 0, copying proceeds further. Furthermore, at this time, if a copy stop signal (when the stop button is pressed or when toner or transfer paper runs out) is output, the process proceeds to the end mode. If the stop signal is not output, the optical system counts 124 clock pulses when it receives the signal generated by the resist signal generator when moving backward. This counting time is set to be slightly longer than the time it takes for the optical system to return to its home position after the signal is emitted from the resist signal generator. 124
The pulses position the optical system in a ready position to advance from its home position and immediately begin the next copy cycle. (Sheet mode) Next, the time chart in Figures 22 and 23, and Figure 17.
Sequence control of the seat mode will be explained using the flowchart shown in the figure. The optical system is also used in the book mode, so if the optical system is in the book mode position, pressing the sheet start button moves the optical system to a predetermined position in the sheet mode. This optical system, which has been moved by the optical system movement motor, is stopped when the micro switch 104 is pressed, and at the same time, the direction of the exposure lamp 3 is changed as shown in FIG. 1, making preparations for sheet copying possible. After this, select the cassette in the same way as in the book mode, turn on the drum motor, pre-exposure, pre-charge, primary charge, AC charge removal, transfer charge, full exposure, blank exposure and count the clock 120, then switch to the sheet mode. Get into action. After counting 120 pulses, the sheet clutch is turned on and the set documents are fed one by one from the tray 27 by the feed roller 29. First document detector 1
After the leading edge of the document is detected at step 06, the clock
When 100 pulses are counted, the paper feed plunger 113 is turned on, the transfer paper is sent out from the cassette, and the original exposure lamp 3 is turned on, while the blank exposure lamp 102 is turned off. Thereby, the sheet is exposed to light while being fed to perform the process of forming a latent image. Then, 50 pulses are counted after paper feeding starts, and it is determined whether the transfer paper has reached the detector 103 by then, thereby detecting a paper feeding error. If the transfer paper has arrived normally, it is determined whether or not the leading edge of the document has arrived at the second detector 107 by the time 60 clock pulses are counted. If the document has not arrived, it is determined that the document is jammed, the copying operation is stopped, and a document jam is displayed. After removing the jammed original, press the sheet start button again to turn on the registration clutch and enter the sheet mode copy cycle again. If the second detector 107 detects a document within 60 clocks, from that point on, the clocks are counted to 50 and the registration clutch is turned off to stop the rotation of the registration rollers 52 and interrupt the advance of the transfer paper.
When the clock is counted for another 50 pulses, the resist clutch is turned on and the transfer paper is advanced to align the leading edge of the transfer paper with the leading edge of the developed image on the drum.
The paper feed plunger is turned off as the transfer paper is gripped by the registration rollers. When the original passes through the first detector 106, a counter for counting the number of originals is incremented by one. Thereafter, a check is made as to whether to continue the copying operation or to temporarily stop it (when there is no paper, no toner, or when the stop button is pressed). If it is a stop, when the transfer paper finishes passing through the transfer paper detection section 103, the original exposure lamp is turned off, the blank exposure is turned on, and the mode shifts to the post-rotation mode. Even if copying continues, if the next document does not arrive at the first detection unit 106 by the time the clock pulses are counted to 50 after the document passes the first detector,
Wait for the transfer paper to finish passing, turn off the document exposure lamp, turn on blank exposure, and shift to post-rotation mode. If the next document reaches the first detection unit 106 during the above 50 counts, an additional 50 counts (count 100)
After clocking), wait for the transfer paper to pass. if,
If the transfer paper is still passing through, the next transfer paper cannot be fed, so it would be bad to send the next document. Therefore, the sheet clutch is turned off to temporarily stop the document (time chart in FIG. 22). After that, when the transfer paper passes, it is detected and the sheet clutch is immediately turned on to feed out the temporarily stopped document, and the paper feed plunger 113 is also turned on to feed the next transfer paper. Thereafter, the sequence of exposure, transfer, and post-rotation continues as described above. On the other hand, in the case of a short-sized transfer paper whose completion of passage of the transfer paper can be detected within 100 clocks after passing through the first detector, the time chart shown in FIG. 23 is passed. Immediately, at this time, the sheet clutch is not turned off, but the next original is fed and exposure continues, and the transfer paper is fed at the signal of the 100th clock. Thereafter, the same sequence control as described above is executed. In this way, since the trailing edge of the transfer paper is detected and the start of exposure of the original is controlled, continuous copying can be performed at high speed regardless of the size of the original and the size of the transfer paper. Note that the detection signals from the detectors 106 and 107 are
Let S ₁ , S ₂ and that from the detector 103 be S ₃ . The control procedure of the seat mode according to this size can be executed by the circuit shown in FIG. 24. In the figure, Copy is a copy button, DISC is a high voltage power supply, M is a drum motor, Blank is a blank exposure lamp, S and CL are sheet clutches, R and CL are resist clutches,
LAMPI is an exposure lamp, PL is a paper feed plunger,
CUP is a predetermined number of sheets completion signal, S ₁ ′ is a signal after the second time of S ₁ , COUT is a counter for counting the number of times of S ₁ ,
CUT1 to CUT5 are counters that count clock pulses CL, and the numerical value indicates a predetermined count value, and when the count is counted, a pulse is generated.CUT5 generates a step signal at a predetermined count value, and is reset by the input signal to its R _terminal.1 , ₃ is the inverted signal of S ₁ and S ₃ , G _{1
G8 to G8} are AND gate circuits, _G9 to _G12 are OR gate circuits, and each operating element (motor, etc.) is kept on or off by an output signal (M, etc.) among the above. A description of the circuit operation will be omitted since it follows the timing chart. (Computer Control) An example of executing the above copying machine sequence control using a microcomputer will be described. FIG. 25 shows the circuit diagram as a block diagram. In the figure, 201 is a computer chip element, 202 is a matrix circuit for giving an input signal to 201, 203 is means for detecting the state of the copying machine, and 204 is a computer chip. 205 is a driver circuit for driving the operating element; 208 is an oscillator that assists the driving; 20
6 is a decoder for displaying signals from the computer, and 207 is a display. The detailed circuit shown in FIG. 25 is shown in FIG. 26. A TI TMS1000 type microcomputer is used as the chip of 201, and the four data inputs K1, K2, K4, K8 and the output 1 are θ ₁ ~
θ ₄ , and has terminals R ₀ to R ₁₂ as output 2. Output 1 is used to display the number of sheets on the displays D ₁ and D ₂ .
These are transmitted through the segment decoder to the display D ₁ ,
Connected to D ₂ . Output 2 is used to control the operation of the load elements and to scan the input matrix circuit. The gate circuit has a so-called decoder function, which is used to combine the signals from the outputs 2 to obtain more output signals. Note that there is one output terminal for _R10 that operates the three types of lamps for displaying paper feeding errors and jams, but the operation of different lamps is controlled by a counter that counts the clock signal for display from _R10 . configured. This gate circuit provides the output of the CPU to the input matrix circuit and output interface circuit. The interface circuit powers up the signal from the gate circuit to drive solenoids, lamps, etc. An AC load or the like is driven by ANDing with the output from the oscillator and outputting it as a trigger signal for a triack or the like. In the matrix circuit section, the outputs from the microprocessor output terminal 2 and from the gate circuit are used as scanning inputs for the matrix circuit. A matrix is constructed such that this scanning line intersects with the input line of the microprocessor, and the point where this intersection becomes a switch corresponds to the input section. If there are X scanning lines and Y input lines to the processor, a maximum of x.y switches is possible. This switch can be used to generate signals from the keyboard switch on the operation panel, micro-switches for other control signals, or various detection circuits (presence or absence of paper,
(master clock detection, etc.) is controlled by a switch, etc. It is due to the level 1 scan line output.
Input to CPU. The circuit operation will be briefly explained. First, the key input from the operation panel is the output terminal of the CPU.
Scanning signals from R0 _~2 , _R9 and gate 265
It is taken into the CPU by the negative signal of R ₄ (signal before machine operation starts). Cassette-related input signals are taken by output _R3 . The captured numerical value (2 digits) is selected by one output of R ₁₁ and R ₁₂ alternately and the 4-bit output of θ1 to 4 simultaneously, and a segment of the required digit is selected, and then D ₁ ,
D ₂ is alternately displayed by 266 and 267 switch elements. After completing the preparation stage such as key entry, the main motor, pre-exposure, etc. are driven by _R4 .
This _R4 signal specifies the matrix input switch (registration signal RS generation, clock pulse CP generation, paper discharge detection CPOS). Therefore, when the drum is rotated by the main motor, each signal for sequence timing can be input. Further, the paper feeding success detection CPIS stop detection STOP is input to the CPU using the document exposure lamp drive signal R ₄ and the blank lamp drive signal R ₇ . Under the condition that the drum rotates, the charger, AC static eliminator, full exposure lamp, paper feed PL,
The resist CL is driven by the outputs of R0 to R2. However, the input command is blocked by the R4 signal. Reading of the first sheet original detector OS1 to the CPU is performed by ANDing the negative output of the paper feed PL operation output R1 from the gate 268 and the sheet clutch operation signal of R8. The input to the second detector OS2 is performed by ANDing the output of R1, the output R2 of the resist clutch, and the transfer sheet feeding success signal CPIS by the gate 270. As described above, input terminals with few CPUs can be used effectively. Also, the optical system moving motor is operated under the AND condition of the gate 271 between outputs R9 and R5 (details will be explained later regarding optical system positioning check in sheet mode). In the case of key entry, R0 to R2 and R9 are sequentially output by a clock, but when operating a control load, the output is of the length required to turn off the load. When CPIS cannot be detected and there is a paper feed error, R1
When the transfer paper is jammed and cannot be ejected (CPOS cannot be detected), a paper jam is indicated by two pulses from the same R10, and the sheet original is jammed and the second detector OS
2 is not activated, a document jam is displayed by 3 pulses from R10. For this purpose, a counter 272 is provided, and its display output is reset by the drum rotation stop signal 4 and the time signal after the power is turned off for jam processing. To explain the computer chip element with reference to FIG. 28, in the figure, the ROM has a master program for executing the sequence of the copying machine arranged in advance and embedded in each address, and each time a specific address is set therein, It is a read-only memory whose contents can be taken out in advance in a well-known matrix circuit, and is programmed in binary code in order from address 0 to the required final address (key entry program, equipment operation program, machine operation program). (exit program, etc.). The RAM is a read/write memory that stores the number of copies and temporary control signals during process control, and is a well-known memory that stores a set of binary codes. An arbitrary set is selected by an address designation signal, and data is written to or read from a plurality of flips or flops within the set. KI is an input section that accepts external signals. ID
is an instruction decoder that decodes the code signal output from the ROM and divides it into more detailed control signals 2 for executing each step. ALU is an arithmetic circuit that processes data.
Acc is an accumulator that stores calculation results.
YR is a register that stores data. RO is a register with a latch function, and its contents are output and used as control output. The procedure for executing the standby flow such as key entry in Figure 16, the process sequence flow in book mode and sheet mode, and the exit mode flow by this CPU and peripheral circuits is shown in Figure 31, which is a detailed flowchart using the instruction code and its code. Details are given in the program code list in Tables 1 and 2. The above list is stored in the ROM in the CPU in step order.
The standby flow, sequence flow, and end flow are executed by reading out this code in chronological order at an extremely high speed (one step of the flow is 10 μsec, etc.). Please refer to some of the detailed flowcharts above.
The operation of the CPU will be explained using, as an example, optical system movement control in preparation for starting scanning immediately before the start of sequence execution in sheet mode. In the seat mode, the optical system must be in a position exclusively for the seat, as described above. If it is not in the correct position, the optical system movement motor is rotated and the forward clutch is actuated to move the optical system. When the stop position is reached, the position detection switch 104 is pressed.
As soon as it is detected that this switch has been pressed, the optical system moving motor and the forward clutch are disconnected, and the optical system stops at the position dedicated to the sheet. This will be explained based on the program steps shown in FIGS. 30a and 30b. A control signal (code) is output from the ROM for each step by a clock signal for driving the CPU. The output is decoded by ID and the program is executed in order. First, a control code is output from the ROM address corresponding to step 1, which is decoded by the ID and sent as a control signal α ₁ to ALU and YR.
The value 9 is set in register YR through ALU. In step 2, R9 of the output registers RO specified by this register YR is set.
In step 3, the input data of the input section KI is
Store in accumulator Acc through ALU.
At this time, since the output of register R9 is output by step 1, the input position of optical system stop position detection switch OHP2 is specified, and whether or not OHP2 is operating is input (see the matrix circuit in Figure 26). ). Therefore, the input signal of K4 at input section KI is 0.
or 1 is input, and the data at this time is stored in Acc as a code with K4 corresponding to the second bit. Next, in step 4, the value 0 is set in register YR through ALU. In step 5, the data of the accumulator Acc stored in step 3 is transferred and stored in the RAM memory address M(00) indicated by register YR. In step 6, this memory M
Determine whether the second bit of data in address (00) is 1. If (yes), the optical system sheet position has been detected, and the next step 7 is executed. However, if it is 0 (NO), it is not detected, so step 7 is skipped and step 8 for moving the optical system is executed. At step 8, 5 is set in register YR. In step 9, R5 of register R0 specified by register YR is set, and this output turns on the forward clutch through the driver. Therefore, together with the output from R9, the optical system begins to move toward the seat position. (See FIG. 26) Step 10 is a jump command to return to label name LB1, that is, step 1, and this loop operation is repeated many times until position detection switch OHP2 is pressed. Reach the optical system seat position and OHP2
When is pressed, the second bit of the input data becomes 1 and step 7 after step 6 is executed. Step 7 is an instruction to jump to label name LB2, so LB
Step 11 specified in step 2 is executed next. In step 11, 9 is set in register YR, and in the next step 12, R9 of register RO specified by register YR is reset. Similarly, R5 of register RO is reset in steps 14 and 15. In this way, the outputs of R9 and R5 are reset, and the optical system moving motor and forward clutch are turned off.
The optical system stops at the seat position. FIG. 29 schematically shows the register addresses of the RAM. The location stored in step 5 of FIG. 30 above corresponds to address (0, 0). Also shown in the figure is a register that stores 1 in response to a flag instruction, which is used as a determining means in another flow step in FIG. Also, the number of input sheets in the key entry cycle of the standby routine flow described later,
A register for storing a count value of the number of copies in a sequence flow cycle, a register for storing in advance the number of counting clock pulses for jam discrimination, the number of counting clock pulses for control load activation timing, etc. are shown in the figure. The types of flags in FIGS. 29 and 31 have the following meanings. display flag...set when displaying D1 stop flag...set when paused, out of paper, etc. entry flag 1...set after key entry entry flag 2...set "1" after entry jam flag 1...transfer paper Jam flag 2...Set when the pulse count for the jam reaches the set number clear flag...Set when the clear key is pressed Sheet mode flag...Set auxiliary cassette in sheet mode flag...Set the auxiliary cassette as the selected pulse flag 1... If the pulse count does not reach the set number, set pulse flag 2... If pulse count for jam is set, set (key entry cycle) Figure 20 shows the operational relationship between the RAM and the key. After the power is turned on, all outputs of the microprocessor are cleared, and the contents of the RAM are also cleared, after which 1 is set at RAM address (0, 1) (hereinafter referred to as address 1) and the process proceeds to the key entry cycle. Key entries include numerical keys 126 from 0 to 9 for setting the desired number of copies, a clear key 127 for correcting the set number of copies, and a key 13 for starting copying.
0 (book mode), 131 (sheet mode), and the stop key 129 which issues a stop command.
(Figure 15) The number of copies can be set up to two digits (99 copies), and the first digit is stored in RAM address 1 and the second digit is stored in RAM address 2.
If no key is pressed, "01" is displayed at the RAM1 address set after the power is turned on, and one copy can always be made without pressing the numeric key. If you want to make two or more copies, press the number key. When a key is pressed, it is determined whether it is a numeric key or another key, and if it is a numeric digit key, the pressed numeric digit is stored in RAM address 1 and displayed, and the next key is waited for. If it is a key other than a numeric key, if it is a clear key, it will clear the data at addresses RAM1 and RAM2, then set 1 to address RAM1 and wait for the key to be pressed again.If it is a copy start key, it will clear the data at addresses RAM1 and RAM2. It determines whether a signal is being output, and if a stop signal is output, it waits for the key to be pressed again. If no stop signal is issued, proceed to the copy sequence. The stop signal is activated when there is no copy paper or developer.
Alternatively, it is issued when the temperature of the fixing heater has not reached a predetermined value. If it is a numeric key, move the data at RAM1 address to RAM2 address, and move the new data to RAM1 address.
Enter the address. Next, if a key other than the numeric key is pressed, the same operation as described above is performed. When the program advances to the copy sequence and exits the key input program, no key input is made even if a key is pressed, and therefore no malfunction occurs. The detailed operation of the CPU in the above key input is clear from the similar detailed flowchart of FIG. 31 for the optical system motor described above. (Jam detection) After counting a certain number of clock pulses CP corresponding to the rotation of the drum, it is determined whether the transfer paper has arrived at the ejection port within a predetermined time from the time when the transfer paper is sent out by the registration roller 101 to the ejection port. Check to see if the paper has arrived. Paper is detected by microswitch 117. aforementioned
Hit the CPOS signal. Transfer paper is registration roller 1
Clock counting starts from the timing sent by 01. Because the CPU operates so fast, it can perform many controls between clocks. Therefore, by including a program in the inner flow that simultaneously counts the clock for jam detection while waiting for various input signals and counting the clock for control timing, it is possible to control many operating elements. It is possible to count the clock for the jam detection timer without loss. (Dynamic count display is possible) If the paper has not reached the detector 117 when the jam detection check is performed, all drive systems (especially high-risk high-voltage power supplies, heaters, etc.) are first turned off, and the copy Stop the operation, and then turn on the jam detection operation indicator lamp. The paper conveyance belt is driven to a state where it can be discharged. The optical system may become distorted when removing paper stuck inside the machine. Therefore, when a jam is detected, the optical system moving motor 114 is turned on to move the optical system to the sheet mode position. When it reaches a predetermined position, the optical system presses the micro switch 104 and a signal is emitted.
The optical system movement motor is turned off. At this time, the optical system does not return even if it is mechanically locked. When the cover is opened to take out the jammed paper and then closed again, the micro switch 105 is activated. A signal from the microswitch issued at this time resets the jam detection. When the start button is pressed again, the plunger 115 for unlocking the optical system is activated, the lock is released, and the spring force returns the optical system to the home position in the book mode. Note that the clock pulse mentioned above has a process speed of 1.
It has an internal oscillator that generates pulses at intervals corresponding to 1 pulse per mm. It can also be generated by optically detecting holes in a rotary plate that rotates at the rotational speed of the drum. In conventional discrete control circuits, it was necessary to provide a key input prohibition circuit during the copy operation, but in the present invention, control is performed sequentially by microprogramming, so the copy operation can be performed once after the key reading step. Once the step is entered, even if a key is pressed, it is not accepted, so even if, for example, the copy start key in the sheet mode is pressed during a copy operation in the book mode, there will be no malfunction. Please note that the terms used in Table 1 are provided by TI.
TMS1000 series “Programmer’s Reference
As explained above, according to the present invention, the first document exposure mode exposes the document on the document table using an optical member that moves back and forth, and the first document exposure mode in which the sheet document is transported by the sheet document transport mechanism. In an image forming apparatus equipped with a second original exposure mode in which a sheet original is exposed and ejected without stopping the sheet, a detection means is provided for detecting a trailing edge of a recording material conveyed for image formation, and a second original exposure mode is provided. In the document exposure mode 1, the optical member that is moving forward for document exposure is moved back based on the rear end detection signal of the recording material from the detection means, and control for ending the document exposure operation in progress is executed. , second
In the original exposure mode, the next original is transferred by the original transport mechanism based on the trailing edge detection signal of the recording material from the detection means, which is used as a reference for controlling the end of the original exposure operation being executed in the first original exposure mode. This is to execute control to start the next document exposure operation. With this configuration, different document exposure operations in image forming operations in the first and second document exposure modes can be performed using the trailing edge detection signal of the recording material without providing separate reference signal generation means for each document exposure mode. can be controlled using a reference signal common to both modes, and in the first document exposure mode, the optical member that is moving forward to expose the document can be returned without moving forward over an unnecessary distance. Therefore, the forward movement of the optical member for exposing the next document can be quickly started, and therefore, the image forming operation in the first document exposure mode can be executed at high speed, and on the other hand, In the second document exposure mode, the next document is transported by the document transport mechanism following the ongoing image forming operation, so that the next document exposure can be started quickly.
Similar to the first original exposure mode, it is possible to perform the image forming operation in the second original exposure mode at high speed.

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【table】 [Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a copying machine to which the present invention can be applied, FIG. 2 is a sectional view showing a paper feeding section when using the manual cassette, and FIG. 3 is an optical A cross-sectional view showing the system and the illumination section, FIG. 4 is a perspective view showing the acrylide of the linear guide device, FIG. 5 is a perspective view showing the drive guide section of the optical system, and FIGS. 6 and 7.
The figure is a sectional view showing the illumination section, FIG. 8 is a diagram schematically showing a conventional linear guide device, FIG. 9 is a sectional view showing the paper feeding section, FIG. 10 is a perspective view thereof, and FIG. 11 is a diagram showing a conventional linear guide device. FIG. 12 is a sectional view of the clutch mechanism that controls the paper feeding device; FIG. 13 is a sectional view of a conventional paper feeding control clutch; FIG. 14 is a perspective view of a loop-forming guide plate; Figure 15 is a front view of the copying operation section, Figures 16, 17, 18 and 1.
Figure 9 is a flowchart of sequence timing.
Figure 20 is a key entry flowchart,
Figure 1 is a time chart in book mode, Figures 22 and 23 are time charts in sheet mode, Figure 24 is a circuit that achieves the time charts in Figures 22 and 23, and Figure 25 is a book using a computer. The control block diagram in the invention, FIGS. 26a and 26b, are the circuit diagram and name diagram of FIG.
Figure 7 is a specific diagram of the matrix circuit in Figure 26, and Figure 2
8 is an internal circuit diagram of the CPU shown in FIG. 26, FIG. 29 is a register address of the RAM shown in FIG. 28, and FIGS. 30 a and b are part of a control flowchart by the CPU. In Figure 1, 3 is an illumination lamp, 4 is the first mirror, 5
3 is a second mirror; 36, 41, and 44 are supporting members;
7 is an inner member, 38 is an outer member,
39 is the retainer, 40, 42, 50 is the roller, 43
is the rail, 48 is the reflective shade, 49 is the support floor, 5
1 is a cam plate, 52 is a register roller, 53 is a paper feed roller, 59 is a cam, 60 is a cam shaft, 62
is a belt, 63 is a pulley, 64 is a clutch drum, 65 is a clutch spring, 66 is a stop ring, 66 ₁ and 66 ₂ are projections, 71 and 72 are guide plates, 71 ₁ and 71 ₂ are slotted holes, and in FIG. 20
3 is an input means for detecting the copying state, commanding the number of copies, copying mode, starting copying, etc., 202 is an input matrix circuit, 201 is a CPU, 207 is a display;
205 is an output driver.

Claims (1)

[Claims] 1. A first document exposure mode in which the document on the document table is exposed by a reciprocating optical member, and a sheet document conveying mechanism that exposes the sheet document while conveying the document without stopping the sheet. an image forming apparatus having a second document exposure mode for ejecting, a selection means for selecting a desired document exposure mode; a conveyance means for conveying the recording material; and a document exposure mode selected by the selection means. Therefore, a process means for forming an image corresponding to the exposed original image on the recording material conveyed to the image forming position by the conveyance means, and a process means for detecting the trailing edge of the recording material conveyed by the conveyance means. a detection means; and a control means for controlling the document exposure operation based on a mode signal indicating the document exposure mode selected by the selection means and a trailing edge detection signal of the recording material from the detection means; In the first document exposure mode, the control means causes the optical member that is moving forward to expose the document to move backward based on the trailing edge detection signal of the recording material from the detection device. Executing the end control of the exposure operation, in the second original exposure mode, after the recording material from the detection means is used as a reference for the end control of the original exposure operation being executed in the first original exposure mode. An image forming apparatus characterized in that the document conveying mechanism causes the document conveyance mechanism to convey the next document based on the edge detection signal and executes control to start the next document exposure operation.