JP3085665B2 - Image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a paper feeder such as a printer and a copier, and more particularly, to a paper feeder containing a plurality of papers stacked one on top of the other. The present invention relates to an image forming apparatus for selecting and feeding the image to an image forming unit.

[0002]

2. Description of the Related Art Conventionally, the number of sheets supplied frequently increases with an increase in the printing processing speed of a printer or the like. In order to achieve the space, there has been proposed an image forming apparatus in which a sheet feeding device is unitized and each unit is stacked up and down so that a printer comes at the top level (Japanese Patent Laid-Open No. 1-275342).

[0003] Such a prior art will be described with reference to FIG. Reference numeral 20 denotes a printer, in which a paper cassette 21 is provided.
And feeds the paper to the printing position 25. pf-1, p
f-2 is a paper feed unit stacked vertically, and the printer 20 is installed at the top of the paper feed unit. Each paper feed unit pf
-1, pf-2 contains sheets of different sizes for each unit, and is configured to be able to be fed to the printing position 25 from the sheet feeding units pf-1, pf-2.

Although not shown, in order to be able to store paper of each size, the position of the horizontal width of the paper, which is well known, is placed on the paper mounting table 26 on which the paper of the paper feed units pf-1 and pf-2 is mounted. Can be changed freely, and the user can freely change and select a desired sheet.

To explain the structure of the paper feed units pf-1 and pf-2, reference numeral 23 denotes a paper feed roller which comes into contact with the uppermost paper placed on the paper mounting table 26 and discharges the paper forward by frictional force. I do. Reference numeral 24 denotes a paper transport path, and each paper feed unit pf-
1, pf-2 penetrates in the vertical direction, and when each unit is stacked, the lower through-hole of the sheet feeding unit pf-1 and the upper through-hole of the unit pf-2 coincide with each other. The paper discharged by the paper feed roller 23 is conveyed upward and guided to a printing position 25 where image formation is performed by a pair of rollers 22 provided at a supply port below the printer 20.

[0006]

However, in the conventional image forming apparatus as shown in FIG. 6, the length of the paper transport path up to the printing position 25 is limited to the upper unit pf-1 and the lower unit pf-1.
Since the printer 20 differs in pf-2, the printer 20
If the pf-1 and the lower paper feed unit pf-2 are erroneously recognized, the timing of the paper conveyance and the image formation is affected, and a correct printing operation cannot be performed. , Pf-2 had to be accurately determined.

Further, even when the same paper feed units pf-1 and pf-2 are stacked, the printer 20 needs to accurately determine the paper feed units pf-1 and pf-2 for the same reason as described above. Was.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a first paper feeding unit having a discrimination code and a second paper feeding unit having a discrimination code below the first paper feeding unit. An image forming apparatus in which image forming means for printing paper supplied from the first or second paper feeding unit is arranged above the first paper feeding unit, Communication means for communicating from the first paper supply unit to the first paper supply unit, second communication means for performing communication from the first paper supply unit to the image forming means, and second supply means for performing communication between the first paper supply unit and the second paper supply unit. A third communication unit that communicates with the paper unit; and a fourth communication unit that communicates with the second paper supply unit to the first paper supply unit. Communication to the unit is performed by the first communication means and the third communication means.
And the communication from the second paper supply unit to the image forming means is performed by the fourth communication means and the second communication means. In order to determine, the first or second
The image forming apparatus is configured to be able to transmit the discrimination code of the sheet feeding unit.

According to the configuration of the present invention, the communication between the image forming means and the second paper feeding unit is performed through the first paper feeding unit. Since there is no need to provide a special communication unit, the cost of the image forming apparatus can be reduced, and the determination time can be reduced because the determination code is transmitted to the first paper supply unit and the second paper supply unit at the same time.

Further, the first paper feeding unit and the second paper feeding unit are provided with the same mechanism, have the same size, have the same pre-assigned discrimination code, and change the discrimination code. It is provided with changing means.

According to the configuration of the present invention, even when the same paper feed unit is stacked, each paper feed unit has a change means for changing the discrimination code. Can be clearly distinguished, and each paper feed unit can be accurately identified.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view of the image forming apparatus. Reference numeral 1 denotes a printer for forming an image on a sheet. Under the printer 1, paper feed units PF-1 and PF-2 are vertically stacked.
-1 and the printer 1 are connected via a pass unit 11 inserted on the paper feed unit PF-1 side. Paper feed unit
Although PF-1 and PF-2 have the same self-determination code, details will be described later.

Paper feed roller 1 in paper feed units PF-1 and PF-2
The paper ejected from 0 is conveyed in the upward direction, passes through the pass unit 11 and temporarily stops at the registration roller 5. On the other hand, the photosensitive member 9 is charged by the charger 2 and L
The toner image is formed on the photoconductor 9 through the exposure process by the ED head 3 and the developing process by the developing device 4. The stopped paper is conveyed to the transfer roller 6 by the rotation of the registration roller 5 in accordance with the timing of forming the toner image, and the toner image is transferred. Then, the transferred toner image is fixed by heating or pressure of the fixing device 7 to form an image. Reference numeral 8 denotes a cleaning unit that cleans untransferred toner on the transfer roller 6.

FIG. 2 is an explanatory diagram when the path unit 11 is connected. Pass unit 11 is paper feed unit PF-1
Or, it is necessary to take the paper from the PF-2 into the printer 1. If the printer 1 and the paper feed units PF-1, PF-2 are not inserted when they are installed, they will not be smoothly conveyed from below. Jams and the like will occur.

In the pass unit 11 shown in FIG. 1, power transmission gears 111 and 114 are meshed with each other on the side, and the rotation of the gear 114 causes the rotation shaft 113 to rotate. The rotation shaft 113 has a rubber-like conveyance roller 11 near its center.
3a and 113a are provided, and a driven roller 113b that is driven in contact with the transport roller 113a is provided. Reference numeral 110 denotes a convex portion (formed at four locations) formed at the lower portion of the pass unit, and as shown in FIG.
The PF-2 is horizontally slid into a fitting portion (formed at four locations) formed around the transport path 12 penetrating the PF-2 in the vertical direction, so that the PF-2 is fitted and inserted into the paper feed unit PF-1 or PF-2. Be worn. 1
Reference numeral 20 denotes a drive gear provided in each of the paper feed units PF-1 and PF-2, and meshes with the gear 111 by the above-described fitting. The rotation of the gear 120 drives the gear 11 through the gear 111.
4 and the rotation of the rotating shaft 113 rotates the transport roller 113a.

In the following, an explanation will be given with reference to an enlarged explanatory view as viewed from the arrow x in the figure. Reference numeral 112 denotes a detection rod (change means).
Reference numeral 122 denotes a detection unit provided on the upper side of the paper feed unit PF-1. In particular, reference numeral 122a denotes a photosensor composed of light receiving and emitting elements (not shown), and reference numeral 122b denotes a shielding plate for shielding between the light receiving and emitting elements. The shielding plate 122b is configured to be rotatable about a rotation axis 122b _1, one end of which is biased by the spring 122b _2, usually not shield the photosensor 122a,
The light from the photo sensor 122a is shielded by fitting and inserting the pass unit 11. That is, pass unit 1
By sliding when inserting 1, the detection rod comes into contact with one end of the shield plate 122 _b on the side opposite to the spring 122 _{b 2,} and rotates the shield plate 122 b to shield the photosensor 122 a.

Thus, even if the self-determination code is the same for each paper feed unit PF-1 and PF-2, only each paper feed unit PF-1 is changed. That is, the paper feed units PF-1 and PF-2 have the same discrimination code in advance,
When the photo sensor 122a is installed in a state where it is not shielded (in a state where the pass unit 11 is not inserted), the printer 1 cannot accurately recognize the installation of the paper feeding units PF-1 and PF-2, and determines that the installation is incorrect. However, the paper feed unit PF-1 starts to operate when the path unit 11 is inserted.
2a is shielded and changed to another discrimination code, whereby the printer 1 correctly recognizes each of the paper feed units PF-1 and PF-2, determines that it is normal, and enables the printer 1 to operate.

Next, a method of determining the upper and lower stages of the sheet feeding units PF-1 and PF-2 will be described. FIG. 3 is an explanatory diagram showing a communication line between the printer 1 and the paper feeding units PF-1 and PF-2. When the printer 1 and the paper feed units PF-1 and PF-2 have been installed, the communication means of the printer 1, the communication means of the paper feed unit PF-1, the communication means of the paper feed unit PF-1, and the paper feed unit PF- Since communication with the second communication means can be performed, communication between the printer 1 and the paper feeding unit PF-2 can be performed via the paper feeding unit PF-1, and the printer 1 performs an initial condition check. . That is, a display means (not shown) is provided which starts the printer print processing procedure if OK in the upper and lower row discrimination check and printer connection check described later, and displays the fact on the printer display section if NG.

The upper and lower tier discrimination check will be described.
As shown in the figure, S is a discrimination code detecting means provided in the printer 1. First, the paper feed units PF-1 and PF-2
At the initial stage, both are set to the discrimination code “0”, and the discrimination code is changed to “1” for the paper feeding unit PF-1 that is inserted by inserting the pass unit 11.

Therefore, if the pass unit 11 is not attached, even if a signal of "1" is sent during the initial check,
Since there is no response of the completion of installation to the discrimination code detection means S, the discrimination code detection means S determines that the pass unit 11 is not inserted during this check processing and displays an installation error on the display means (not shown) of the printer 1. I do.

As a detecting method, a discrimination code detecting means S
First transmits each select code SEL. That is, in the present invention, first, the select code SEL “1” is output, and then the select code SEL “0” is output, and the paper feed units PF-1 and PF-2 have the self-determination code “0” or “ 1 "and the transmitted select code SEL are collated, and if they match, the matching paper supply unit replies to the discrimination code detection means S of the printer 1 through communication, and the installation status is checked.

As shown in FIG. 1, SCKD is a printer 1
Is the serial clock data transmitted from the printer 1, SOD is the serial output data transmitted from the printer 1, SID
Is serial input data input from each of the paper feed units PF-1 and PF-2 to the printer 1, and is used for communication between the printer 1 and the paper feed units PF-1 and PF-2.

FIG. 4 is a timing chart of a clock synchronous interface for communication when the select code SEL outputs "0". In this interface, 8-bit transfer is performed twice continuously, and data is converted to a serial clock signal. Transmission or reception is performed for each bit in synchronization. That is, the input data SID to the printer 1 is output from the paper feed unit PF-1 or PF-2 in synchronization with each fall of the serial clock data SCKD, and the transmission data SOD from the printer 1 is the serial clock data SCKD of the serial clock data SCKD. The output is configured to be synchronized with the falling edge.

This communication is normally performed when the user selects the paper feed unit PF-1 when printing. That is, if the selected unit is PF-1, a select code SEL of "1" is transmitted, and the selected unit is configured to operate by the communication.
By outputting the select code SEL, communication such as rotation of the paper feed roller 10 of the selected unit, exchange of the size of the installed paper, and the like are performed.

Next, a means for determining the presence or absence of connection with the printer 1 is performed using an initial check stage. That is, the printer 1 determines whether or not the paper feed units PF-1 and PF-2 are connected to the printer 1 and whether or not the paper feed units PF-1 and PF-2 are connected to only one or two stages. Is used to determine

In this case, by using the select code SEL transmitted from the discrimination code detecting means S of the printer 1 and the specific bit of the transmission data SID when responding, "0" if connected, "0" if not connected Detected by 1 ”signal.

First, the printer 1 and the paper feed units PF-1 and PF
When -2 is unconnected, no matter which select code SEL is transmitted by the printer 1, there is no connection response from the transmission data SID, so that "1" is always detected and it can be recognized as unconnected.

Next, only the paper feed unit PF-1 is used for the printer 1.
Is not connected, first, the select code SEL “1” of the upper paper feed unit is transmitted, and since it matches the self-determination code, the transmission data SID “0” is transmitted from the paper feed unit PF-1. . Here, the serial clock signal SC
When the specific bit of KD falls, "0" is output to the discrimination code detection means S, whereby it is detected that the unit PF-1 and the printer 1 are connected.

Subsequently, the discrimination code detecting means S transmits the select code SEL "0". However, since the selected sheet feeding unit PF-2 is not connected and does not exist, the discrimination code detecting means S is set to "1". Detect signal. As a result of the above work, 2
The paper feed unit PF-2 of the lower stage is determined to be unconnected, the print process is started ignoring the second stage, and when the user selects the second stage, the fact that it does not exist is displayed on the printer display for the first time. indicate.

Finally, when the paper feed unit PF-2 is connected to the printer 1 (the same as when the paper feed unit PF-1 is connected without the pass unit 11 being inserted), an installation error is displayed in the same manner as described above. I do.

Next, a second embodiment of the present invention will be described with reference to FIG. In each of the units pf-1 and pf-2, a is a switch for distinguishing the upper stage, and when the paper feed unit a stacked on the upper stage is turned on, the discrimination code detecting means S recognizes that the upper stage is the paper feed unit and switches the switch. It recognizes that the paper feed unit for which a is OFF is on the lower side. On the other hand, the opposite case exists but is omitted.

[0032]

According to the present invention, the communication between the image forming means and the second paper feeding unit is performed by communicating the image forming means with the second paper feeding unit via the first paper feeding unit. It is possible to provide an image forming apparatus that does not require special communication means and can reduce the cost of the image forming apparatus.
In addition, the determination code transmission from the image forming unit to the first paper feeding unit is also transmitted to the second paper feeding unit at the same time, so that the determination time for each paper feeding unit can be reduced.

Further, since each sheet feeding unit is provided with a change means for changing the discrimination code, the discrimination code of the changed sheet feeding unit and the discrimination code of a sheet feeding unit which is not changed can be clearly distinguished. It is possible to provide an image forming apparatus that accurately determines a sheet feeding unit.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram for connecting pass units.

FIG. 3 is an explanatory diagram showing a communication line between a printer and a paper feeding unit.

FIG. 4 is a timing chart of communication when a select code “0” is output.

FIG. 5 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 6 is a schematic sectional view of a conventional image forming apparatus.

[Explanation of symbols]

 1: Printer 10: Paper feed roller 11: Pass unit 112: Detection rod (detection means) 12: Transport path 122: Detection unit 122a: Photo sensor 122b: Shield plate PF-1: Paper supply unit PF-2: Paper supply unit

Claims (2)

(57) [Claims] A first paper feeding unit having a discrimination code and a second paper feeding unit having a discrimination code below the first paper feeding unit; In the image forming apparatus, an image forming unit that prints a sheet supplied from the first or second sheet feeding unit is disposed in an upper stage, and communication is performed from the image forming unit to the first sheet feeding unit. A first communication unit, a second communication unit that communicates from the first paper supply unit to the image forming unit, and a second communication unit that communicates from the first paper supply unit to the second paper supply unit. Communication means for communicating from the second paper feeding unit to the first paper feeding unit;
Communication from the image forming unit to the second paper feeding unit is performed by the first communication unit and the third communication unit, and the communication from the second paper feeding unit to the image forming unit is performed. Is configured to be performed by the fourth communication unit and the second communication unit. In order to determine the first or second sheet feeding unit,
An image forming apparatus, wherein the image forming unit is configured to be able to transmit a discrimination code of the first or second sheet feeding unit. 2. The first paper feed unit and the second paper feed unit are provided with the same mechanism, have the same size, have the same pre-assigned discrimination code, and change the discrimination code. The image forming apparatus according to claim 1, further comprising a change unit.