JPH03288740A - Image forming device - Google Patents

Abstract

PURPOSE:To economize inutile time for mounting a cassette by installing a means for judging the selection to the second precedence paper feeding port after the rise of a bottom plate is detected, when the paper feeding cassette is mounted at the first precedence paper feeding port and the rise of the bottom plate of the paper feeding cassette is not detected. CONSTITUTION:When an electric power source is turned ON, and an automatic selecting means E selects a paper feeding port, if a paper feeding cassette is mounted at the first precedence paper feeding port, and the rise of the bottom plate of the paper feeding cassette is not detected, a paper feeding port selection judgement permission means F judges the selection of the second precedence paper feeding port after detecting the rise of the bottom plate. Accordingly, after the judgement for the selection of the second precedence paper feeding port is permitted, an automatic paper feeding port selecting means E selects the paper feeding port, if a detecting means D detects the existence of paper in the paper feeding cassette mounted at the first precedence paper feeding port.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to image forming apparatuses such as various printers, copiers, facsimile machines, and the like.

[Conventional technology]

An image forming device such as a copying machine has multiple paper feed slots each with a paper feed cassette removably attached thereto, and a cassette that detects whether or not a paper feed cassette is installed in each paper feed slot. installation detection means; bottom plate lifting means for raising the bottom plate of each installed paper feed cassette; lift detection means for detecting the rise of the bottom plate; detecting the presence or absence of paper in each paper feed cassette when the bottom plate is in the raised state. Some devices are equipped with a paper presence/absence detection means and a paper feed port automatic selection means for automatically selecting a paper feed port in which a paper feed cassette containing paper is attached when the power is turned on, according to a predetermined priority order.

In this type of image forming apparatus, when the paper feed 2 automatic selection means selects the paper feed port when the power is turned on, if a paper feed cassette with paper is installed in the first priority paper feed port, If you select that paper feed slot, and if the paper cassette is not installed in the first priority paper feed slot, or even if it is installed, it is at the paper end (no paper), the other paper cassettes after the second priority I try to select the paper opening.

[Problem to be solved by the invention]

However, in such a conventional image forming apparatus, as described above, the presence or absence of paper in the paper feed cassette is detected by the paper presence/absence detection means when the bottom plate is raised.
If the power is turned on with the bottom plate of the paper cassette attached to the priority paper feed slot lowered, the paper end will be detected even if there is paper in the paper cassette, and the paper end will be detected. Therefore, there is a problem in that the second or subsequent priority paper feed port is selected.

Therefore, information indicating the paper feed slot is displayed on the display panel installed in the main body of the device, and the user who sees this information can see that there is no paper in the paper feed cassette installed in the first priority paper feed slot. When the user determines that there is no paper in the cassette, he pulls out the paper cassette to replenish it, but when he finds out that there is no paper in it, he has to put it back in, which is a waste of time and effort.

This invention has been made in view of the above points, and aims to solve the conventional problems as described above.

[Means to solve the problem]

In order to achieve the above object, the present invention has a plurality of paper feed ports each having a paper feed cassette removably attached thereto, and a paper feed port for each paper feed port, as shown in the functional block diagram in FIG. cassette attachment detection means A for detecting whether or not a cassette is attached; bottom plate raising means B for raising the bottom plate of each attached paper feed cassette; raising detection means C for detecting the rise of the bottom plate; Paper presence/absence detection means for detecting the presence or absence of paper in each paper feed cassette in the raised state;
In an image forming apparatus equipped with a paper feed port automatic selection means E that automatically selects a paper feed port in which a paper feed cassette containing paper is installed according to a predetermined priority order when the power is turned on, When the paper feed port automatic selection means E selects a paper feed port, if a paper feed cassette is attached to the first priority paper feed port and the rise of the bottom plate of the paper feed cassette is not detected, After the rise of the bottom plate is detected, paper feed port switching determination permission means F is provided to determine whether or not to switch to selection of the second priority paper feed port.

[For production]

In the image forming apparatus according to the present invention, when the paper feed port automatic selection means E selects a paper feed port when the power is turned on, the paper feed cassette is installed in the first priority paper feed port, and the paper feed cassette is When the rise of the bottom plate is not detected, the paper feed port switching determination permitting means F makes a judgment as to whether or not to switch to selection of the second priority paper feed port after the rise of the bottom plate is detected.

Therefore, the paper feed port automatic selection means E, which is permitted to determine whether or not to switch to selection of the second priority paper feed port, will not be able to select the paper feed port installed in the first priority paper feed port at that point. If the paper presence/absence detection means does not detect the presence of paper in the paper cassette, the paper presence/absence detection means detects the presence of paper in the paper feed force sensor 1 installed in the second priority paper feed port. If it is detected, the selection is switched to that paper feed port.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described with reference to FIG. 2 and subsequent figures.

FIG. 2 is a schematic configuration diagram showing only a paper feeding section of an image forming apparatus according to an embodiment of the present invention.

This paper feed section 1 is provided in a main body 2 of the copying machine, and each of its paper feed ports 3 and 4 is provided with a paper feed cassette 7 which is movably provided with bottom plates 5 and 6 on which a plurality of sheets of paper are placed respectively. .8 is installed.

Inside the paper feed section 1, for example, reflective photosensors are used to detect the attachment of the paper feed cassettes, which are located close to and opposite to the tips of the cases 9 and 10 of each paper feed cassette 7°8. cassette detection sensors 11 and 12 are arranged, and a rotating shaft 13a is provided on the back side of each case 9 and 10.
, 14a are provided which are pivotally connected to the bottom plate so as to be able to swing vertically.

Further, at the upper part of the paper feed cassette 7.8, there is a paper feed roller (feed roller) which is biased downward by a spring (not shown) and rotates in the direction of the arrow when a paper feed clutch is turned on using driving force from a main motor (not shown). paper roller) 15.16
Upper limit detection sensors 17 and 18 are respectively disposed at opposing positions on the upper surface of the paper feed roller 15 and 16 in the circumferential direction, and furthermore, a light shielding plate 22 and 23 is integrated at the rear of each of the paper feed rollers 15 and 16 by means of a rotating shaft 20 and 21. Paper end detection sensors 26 and 27 using photointerrupters are respectively arranged corresponding to the raised positions of the light shielding plates 22 and 23.

Here, it is assumed that the paper feed cassette 7 is not installed in the paper feed port 3, and when the paper feed cassette 7 is installed in the paper feed port 3 from that state, the rotating shaft of the bottom plate lifting motor, which will be described later, is linked to the paper feed cassette 7. The gear fixed to the rotary shaft 13a of the bottom plate lifting arm 13 meshes with the sector gear fixed to the rotating shaft 13a of the bottom plate lifting arm 13, and at the same time, the bottom plate lifting motor starts driving in response to an instruction from a control section to be described later.

Then, when the driving force of the bottom plate lifting motor is transmitted to the sector gear, the bottom plate lifting arm 13 rotates upward from the position shown by the imaginary line, and its tip is attached to the case 9 of the paper feed cassette 7.
The bottom plate 5 is lifted upward while being brought into contact with the back surface of the bottom plate 5 through the notch 7a formed in the bottom plate.

After that, when the uppermost paper placed on the bottom plate 5 hits the paper feed roller 15 and lifts it slightly, the upper limit detection sensor 17 detects this and outputs a detection signal to the control unit to stop the bottom plate lifting motor. As a result, the rotation of the bottom plate lifting arm 13 stops at the position shown by the solid line, and the bottom plate 5
also stops rising.

Incidentally, when the paper feed cassette 7 is pulled out from the paper feed port 3, the gear of the bottom plate lift motor and the sector gear disengage in conjunction with this, and the bottom plate lift arm 13 falls under its own weight.

On the other hand, when the paper feed cassette 7 is not installed, the fisher 24 is at the position shown by the imaginary line, and when the bottom plate 5 is pushed up and its top end is pushed up by the uppermost paper, it rotates in the clockwise direction. As a result, the light shielding plate 22 enters the paper end detection sensor 26 and its optical path is blocked, so that the output signal of the paper end detection sensor 26 changes.

Therefore, depending on the voltage level of the signal, the control section
The presence or absence of paper in the paper feed cassette 7 can be determined.

Note that a notch (not shown) is formed in the portion of the bottom plate 5 that faces the fish 24, and when the bottom plate 5 rises with no paper placed on it, the fish 24 is rotated upward by the cutout. Therefore, the control unit continues to detect the absence of paper.

Here, the sequence operation when the paper feed cassette 7 is attached/detached has been described, but since the same operation is performed when the paper feed cassette 8 is attached/detached, a description thereof will be omitted.

Note that 28 and 29 are a pair of paper feed rollers, and 30 is a pair of registration rollers. For example, when a copy command is issued by pressing the copy start key with the paper feed port 4 selected, the drive of the main motor is started. , the paper feed clutch is turned on at a predetermined timing, the paper feed roller 16 and the paper feed roller pair 29 are rotationally driven, and the uppermost paper on the bottom plate 6 is fed.

Thereafter, the paper is temporarily stopped with its leading end in contact with the pair of registration rollers 30, and the pair of registration rollers 30 is driven in synchronization with the leading end of the image on the photoreceptor drum (not shown) to the image transfer section. send to.

FIG. 3 is a block diagram showing a control system of a copying machine using this paper feeding section 1. As shown in FIG.

The control unit 40 of the copying machine includes a CPU 41 that executes various processes.
, a ROM 42 that stores various fixed data including control programs for operating the CPU 41, a RAM 43 that temporarily stores various data, and a ■○ interface 44 that controls the input and output of various signals. It is a computer system that centrally controls the entire copying machine including the paper feed section 1.

The CPU 41 inputs instruction signals from the operation panel 45 and inputs instruction signals from the cassette detection sensors 11, 12 .
Upper limit detection sensor 17, 18. Paper end detection sensor 2
Detection signals from various sensors and switches such as 6 and 27 are input through the I10 interface 44, and the
Bottom plate lift motors 46, 47 via interface 44
It controls various sequence devices such as various motors and clutches, and outputs signals for display control to the operation panel 45.

The ROM 42 contains the 2 data shown in Figure 2 as fixed data.
Data indicating predetermined priority selection orders for the two paper feed ports 3 and 4 is stored.

In this embodiment, priority is given to the paper feed port 3.

The operation panel 45 includes various operation keys including a copy start key 45a and a cassette (paper feed slot) selection key 45b, and a cassette 981 that is displayed by lighting each LED.
Display section 45c (corresponding to the first paper feed cassette 7), Kaya 982 display section 45d (corresponding to the second paper feed cassette 8)
It is equipped with various indicators including.

The paper feed slot selection key 45'b is a key for selecting either one of the paper feed cassettes 7 and 8;
Each time is pressed, Kaya 981 display section 45c and Kaya 982
The display on the display section 4-5d switches alternately.

Next, the operation of this embodiment configured as described above will be specifically explained with reference to FIG. 4 and subsequent figures.

FIG. 4 is a flowchart showing an initial routine for paper feed port selection by the CPU 44, which is called only once by a main routine (not shown) at power-on.

When the process starts, it is determined whether or not the first paper feed cassette 7 is at the paper end, that is, whether the paper end detection 1-sensor 26 is on, and if the paper is not at the end, the first paper feed port 3 is selected. Kaya 981 display section 45
After lighting c, the process returns to the main routine.

Further, if the first paper feed cassette 7 is at the paper end, it is determined whether the upper limit detection sensor 17 is in the on state, and if not, it is determined whether the cassette detection sensor 11 is in the on state.

If the cassette detection sensor 11 is not on, it remains as is; if it is on, the check flag 1 is set, the first paper feed port 3 is selected, and the cassette 981 display section 45c is selected.
Light up and return to the main routine.

On the other hand, if the upper limit detection sensor 17 is in the on state, it is determined whether or not the second paper feed cassette 8 is at the paper end, that is, whether the paper end detection sensor 27 is in the on state. For example, after selecting the second paper feed port 4 and lighting up the display section 45d of the shade 982, the process returns to the main routine.

2 On the other hand, if the second paper feed cassette 8 is at the paper end, it is determined whether the upper limit detection sensor 18 is in the on state or not, and if it is in the on state, the first paper feed port 3 is selected and the paper 981 display section 4 is displayed.
After lighting 5c, the process returns to the main routine.

Further, if the upper limit detection sensor 18 is not on, it is determined whether or not the cassette detection sensor 12 is on.
After setting, the first paper feed port 3 is selected, the display section 45c of the color 981 is turned on, and the process returns to the main routine.

5 to 7 are subroutines that are constantly called by the main routine (not shown). First, the subroutine for raising the bottom plate in FIG. 5 will be explained.

When this routine starts, it is first determined whether or not the cassette detection sensor 11 is in the on state, and if it is not in the on state, the routine immediately proceeds to a determination as to whether or not the cassette detection sensor 12 is in the on state.

If the cassette detection sensor 11 is on, it is determined whether the upper limit detection sensor 17 is on, and if the upper limit detection sensor 17 is on, it is determined whether the bottom plate lifting motor 46 is on.

If the bottom plate lifting motor 46 is not on, it remains as is; if it is on, it is turned off, and then the process proceeds to a determination as to whether or not the cassette detection sensor 12 is on.

On the other hand, if the upper limit detection sensor 17 is not in the on state, it is determined whether or not the bottom plate raising motor 46 is in the on state. Determine whether or not it is on.

If the cassette detection sensor 12 is not on, the process directly returns to the main routine, and if the cassette detection sensor 12 is on, it is determined whether the upper limit detection sensor 18 is on.

If the upper limit detection sensor 18 is on, it is determined whether or not the bottom plate lift motor 47 is on. If it is not on, it remains as is; if it is on, it is turned off, and then the process returns to the main routine. .

On the other hand, if the upper limit detection sensor 18 is not in the on state, it is determined whether or not the bottom plate lifting motor 47 is in the on state,
If it is on, leave it as is; if not, turn it on and return to the main routine.

According to this process, for example, when paper is fed from the paper feed cassette 7, the upper limit detection sensor 17 is turned off, the bottom plate lifting motor 46 is turned on, and the bottom plate 5 is turned off.
When the upper limit detection sensor 17 turns on again, the bottom plate lift motor 46 is turned off and the bottom plate 5 stops rising, so that the upper surface of the paper can always be kept at a constant height that is optimal for paper feeding. I can do it. Of course, paper cassette 8
The same applies to

Next, when the paper feed port selection check 1 subroutine of FIG. 6 starts, it is first determined whether or not the check flag 1 is set, and if it is not set, the process directly returns to the main routine.

Also, if check flag 1 is set, it is determined whether or not the upper limit detection sensor 15-17 is on, and if it is not on, the process returns to the main routine, and if it is on, the first paper feed cassette is 7 is the paper end or not.

If the first paper feed cassette 7 is not at the end of paper, the check flag 1 is immediately reset and the process returns to the main routine.
Determine whether or not is the paper end.

If the second paper feed cassette 8 is not at paper end, the selection is switched to the second paper feed port 4 and the paper 981 display section 4 is switched to the second paper feed port 4.
5c and turn on the cassette 2 display section 45d,
The check flag l is reset and the process returns to the main routine.

On the other hand, if the second paper feed cassette 8 is at the paper end, it is determined whether the upper limit detection sensor 18 is on or not. If it is on, the check flag 1 is reset and the process returns to the main routine.

Further, if the upper limit detection sensor 18 is not on, it is determined whether or not the cassette detection sensor 12 is on. 1 and return to the main routine.

Next, when the paper feed port selection check 2 subroutine shown in FIG. 7 starts, it is first determined whether or not the check flag 2 is set, and if it is not set, the process directly returns to the main routine.

Also, if the check flag 2 is set, it is determined whether the upper limit detection sensor 18 is on or not, and if it is not on, the process returns to the main routine as is, and if it is on, the second paper feed cassette 8 is filled with paper. Determine whether it is the end or not.

If the second paper feed cassette 8 is at the end of paper, it remains as is; otherwise, the selection is switched to the second paper feed port 4 and the color 981 display section 45c is turned off.

After lighting the cassette 2 display section 45d, the check flag 2 is reset and the process returns to the main routine.

As described above, in this embodiment, when the paper feed port is selected when the power is turned on, the paper feed cassette is installed in the first priority paper feed port 3 in FIG. If it is not detected by the upper limit detection sensor 17, after the rise of the bottom plate 5 is detected, it is determined whether to switch to the second priority paper feed port 4, and at this point, the first priority paper feed port 4 is selected. If there is no paper in the paper feed cassette attached to the paper feed port 3, and if there is paper in the paper feed cassette attached to the second priority paper feed port 4, the selection is switched to that paper feed port.

Therefore, even if the power is turned on with the bottom plate of the paper cassette set in the first priority paper feed slot lowered, if there is paper in the paper cassette, the second You will never be switched to selecting a priority paper source.

Note that the present invention is not limited to copying machines, but can be similarly applied to various image forming apparatuses such as various printers including laser printers and facsimile machines.

〔Effect of the invention〕

As explained above, in the image forming apparatus according to the present invention, even if the power is turned on with the bottom plate of the paper feed cassette set in the first priority paper feed port lowered, the paper feed As long as there is paper in the cassette, selection of paper feed ports after the second priority will not be performed.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing the basic configuration of the present invention. FIG. 2 is a schematic configuration diagram showing only the paper feed section of a copying machine which is an embodiment of the present invention. FIG. 3 is a control system of the copying machine as well. FIG. 4 is a flow diagram showing the initial routine for paper feed port selection by the CPU 4.1, and FIG. 5 is a flow chart showing the subroutine for raising the bottom plate. FIG. 6 is a flow chart showing the paper feed port selection check. FIG. 1 is a flow diagram showing a subroutine of No. 1; 9. Similarly, FIG. 7 is a flowchart showing the subroutine of paper feed port selection check 2. ■... Paper feed section 2... Copying machine main body 3, 4... Paper feed port 5.6... Bottom plate 7, 8... Paper feed cassette 11.12... Cassette detection sensor 13.14 ... Bottom plate rising arm 15.16 ... Paper feed roller (paper feed roller) 17.18.
・・Upper limit detection sensor 24.25・Fish 26.27・Paper end detection sensor 41・・CP
U 42...ROM 45...Operation panel 45c
...Cassette 1 display section 45d...Kaya 982 display section 46.47...Bottom plate lift motor 0

Claims (1)

[Claims] 1. A plurality of paper feed ports into which paper feed cassettes are removably attached, cassette attachment detection means for detecting whether or not a paper feed cassette is attached to each of the paper feed ports, and a bottom plate lifting means for raising the bottom plate of a paper cassette; a rise detection means for detecting the rise of the bottom plate; a paper presence/absence detection means for detecting the presence or absence of paper in each paper feed cassette when the bottom plate is raised; In an image forming apparatus, the image forming apparatus is equipped with a paper feed port automatic selection means for automatically selecting a paper feed port in which a paper feed cassette is installed according to a predetermined priority order. When the automatic selection means selects a paper feed port, if a paper feed cassette is attached to the first priority paper feed port and the rise of the bottom plate of the paper feed cassette is not detected, the rise of the bottom plate is detected. 1. An image forming apparatus comprising: a paper feed port switching determination permitting means for determining whether or not to switch to selection of a second priority paper feed port after the second priority paper feed port is detected.