JP3140210B2 - 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 relating to a paper feeder such as a printer and a copying machine, and more particularly, to stacking two identical paper feed units each containing a plurality of papers on top of one another so that the units can be used for printing. The present invention relates to an image forming apparatus for selecting and feeding to an image forming unit.

[0002]

2. Description of the Related Art Conventionally, the number of sheets supplied frequently increases as the printing processing speed of a printer or the like increases, so that a large amount of sheets can be stored, the sheets are fed to a printing apparatus, and the number of sheets is reduced. 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).

FIG. 5 shows a conventional image forming apparatus. Reference numeral 20 denotes a printer, which includes a paper feed cassette 21 therein, from which paper is supplied to perform printing. Reference numerals pf-1 and pf-2 denote paper feed units stacked one above the other, and the printer 20 is installed at the highest level. Each of the units pf-1 and pf-2 contains paper of a different size for each unit, and a paper cassette 21 containing paper of each size requested by an operator at the time of printing.
Each of the paper feed units pf-1 and pf-2 is selected and printing is performed. Here, the sheet feeding units pf-1 and pf-2 are mass-produced in the same shape for the purpose of efficiency and cost reduction by mass production, and two sets are sold as an option of the printer 20. I have. Therefore, in order to be able to store paper of each size, the position of the known width of the paper can be freely changed on the paper mounting table 26 on which the paper of the paper feeding units pf-1 and pf-2 is mounted. (Not shown), the user can freely replace and select a desired sheet.

The structure of the paper feed units pf-1 and pf-2 will now be described. 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 unit pf-1, pf-
2, the lower through-opening of the sheet feeding unit pf-1 and the upper through-opening of the unit pf-2 coincide with each other when the units are stacked. Then, the paper discharged by the paper feed roller 23 is conveyed upward, and a printing position 2 where image formation is performed by a pair of rollers 22 provided at a supply port below the printer 20.
It is led to 5.

The switches a ₁ and a _{2 in} each of the units pf-1 and pf-2 are switches for discriminating between an upper stage and a lower stage. For example, if a ₁ is turned on and a ₂ is turned off, the printer 20 sets the pf-1 to Recognizing that pf-2 is on the upper side, it performs the subsequent paper feed control. The reason for providing the switches a ₁ and a _{2 is} that the length of the paper transport path up to the printing position 25 is different between the upper unit pf-1 and the lower unit pf-2, so that the unit (pf -1 or pf-2) to control the conveyance at an accurate timing according to the image formation so as to eliminate malfunction. Therefore, if the printer 20 recognizes the sheet feeding unit in the opposite way, the timing of sheet conveyance and image formation is affected, and a correct printing operation cannot be performed.

[0006]

Therefore, in such an apparatus, there is a possibility that the upper unit pf-1 and the lower unit pf-2 are set and installed by the user, so that they may be set incorrectly. Not only did it break the equipment.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an image forming apparatus that can automatically determine upper and lower units without setting the upper and lower units in an apparatus in which sheet feeding units are unitized and stacked. The purpose is to do.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method for storing a plurality of sheets under an image forming means for printing an image on the sheets, and A sheet feeding unit having a feeding mechanism for feeding, and a sheet feeding unit identical to the sheet feeding unit are stacked and arranged on the upper and lower tiers, and each sheet feeding unit is configured to be selectable. In the image forming apparatus configured to be able to supply the paper fed from the paper feeding unit to the image forming unit from the paper feeding unit, each of the paper feeding units has a lower determination code assigned in advance, and A change unit for changing the discrimination code to the discrimination code of the upper unit in the paper unit, and a case where the discrimination code changed to the discrimination code of the upper unit by the change unit is loaded on the upper row, and the one not changed is loaded on the lower row, Said changing means Configuring and that and a discrimination code detecting means for determining that the upper or lower by respectively detecting a discrimination code for each of the paper feeding unit that is more segmented.

A pass unit provided with a transport roller for guiding the paper to the image forming means is provided between a paper supply port on the lower side of the image forming means and a feed port of a paper feeding unit disposed immediately below the image forming means. The pass unit is configured to be insertable into the paper feeding unit, and the discrimination code can be changed by inserting the pass unit.

Further, when the paper feed units are stacked on the upper and lower tiers without changing the discrimination code, an arrangement error may be detected.

[0011]

According to the construction of the present invention, the discriminating code of the lower unit is set in advance and is changed to the code for discriminating the upper unit by the changing means. ) Can be clearly distinguished and can be automatically identified by the upper and lower tier detection means of the printer.

Further, since it is impossible to detect the upper and lower tiers of the sheet feeding unit unless the path unit is inserted into the sheet feeding unit, it is possible to determine that there is a mistake in installation, and the insertion error of the path unit is eliminated. Further, the installation state can be easily shown to the user by detecting the installation error.

[0013]

Embodiments of the present invention will be described below 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 paper, and paper feed units PF-1 and PF-2 are vertically stacked below the printer 1. Particularly, the upper paper feed unit PF-1 and the printer 1 Are connected via a pass unit 11 inserted into the paper feed unit PF-1. The paper discharged from the paper feed rollers 10 in the paper feed units PF-1 and PF-2 is conveyed upward and temporarily stops at the registration rollers 5 through the pass unit 11. 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 rotated by the rotation of the registration roller 5 in synchronization with the timing of forming the toner image.
The toner image is transferred to the transfer roller 6 and 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. The pass unit 11 is necessary to take the paper from the paper feed unit PF-1 or PF-2 into the printer 1, and is not inserted when the printer 1 and the paper feed units PF-1 and PF-2 are installed. If it is worn, it will not be smoothly transported from below, and jams will occur. Therefore, it is necessary to provide a detecting means for judging whether or not the path unit is inserted. In the present invention, however, it is configured to be able to detect together with the discrimination of the upper and lower stages of the sheet feeding units PF-1 and PF-2 described later. .

In the pass unit 11 shown in FIG. 1, power transmission gears 111 and 114 are meshed with each other on the side. The rotation of the gear 114 causes the rotation shaft 113 to rotate. The rotation shaft 113 has a rubber-like conveyance roller 113 near its center.
a, 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 places) formed at the lower portion of the pass unit. As shown in the figure, the convex portion 110 is formed around the transport path 12 which passes through the paper feed units PF-1 and PF-2 in the vertical direction. By sliding in the lateral direction to the formed fitting portions (formed at four locations), the sheet feeding unit PF-1 or PF-2 is fitted and inserted. Reference numeral 120 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 rotational drive of the gear 120 transmits power to the gear 114 through the gear 111, and the rotation of the rotating shaft 113 rotates the transport roller 113 a.

In the following, a description 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 (detection 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. As a result, the self-determination code described later is changed. That is, the paper feed units PF-1 and PF-2 have a code for recognizing the lower stage in advance, and the photo sensor 1
Even if the printer 22 is installed in a state where it is not shielded (in a state where the pass unit 11 is not inserted), the printer 1 recognizes that there is no upper unit and determines that the installation is incorrect. However, the photo sensor 122 is not inserted until the pass unit 11 is inserted.
This is changed to a code that shields the printer 1 and determines that the printer 1 is in the upper stage. The code is recognized by the printer 1 and is determined to be normal, so that the printer 1 can be operated.

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 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 / lower stage discrimination check will be described.
As shown in the figure, S is a discrimination code detecting means provided in the printer 1. The discrimination code detection means first transmits each select code SEL. That is, in the present invention, first, the select code SEL “1” is output (actually, output as “L (low)”), and then the select code SEL “0” is output.
(Actually output as “H (high)”), and each of the paper feed units PF-1 and PF-2 collates the current self-determination code (not shown) with the transmitted select code SEL. If they match, the matching paper supply unit replies to the discrimination code detecting means S of the printer 1 through the communication described below, and the installation status is checked.

Here, in the sheet feeding units PF-1 and PF-2, the discrimination code "0" is set at the initial stage (when the discrimination code coincides with the select code, the printer 1).
Is determined to be the lower stage), and the sheet feeding unit inserted by inserting the path unit 11 is the detection unit 1
By the operation of 12, the code is changed from the code "0" to the determination code "1" for determining that the printer is at the upper stage. Therefore,
If the pass unit 11 is not attached, even if a signal of “1” is sent during the initial check, the discrimination code detecting means S
Since there is no response indicating that the installation has been completed, 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.

As shown in FIG. 2, SCKD is a serial clock signal transmitted from the printer 1, and SOD is a printer 1
Serial data and SID from each paper feed unit
Serial data input from the printers PF-1 and PF-2 to the printer 1 for communicating 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 falling of the clock signal SCKD, and the transmission data SOD from the printer 1 is output from the serial clock signal SCKD. It is configured to output in synchronization with falling.

This communication is normally performed when the user selects the paper feed unit PF-1 when printing. In other words, the select code ("1" in the case of PF-1) SEL of the selected unit is transmitted, and the selected unit is configured to operate by the above-described communication, and while the select code SEL is being output. The communication (rotation of the paper feed roller 10 of the selected unit, exchange of the size of the installed paper, etc.) shown in FIG.

However, since the above-mentioned communication is not performed at the initial check stage, the presence / absence of the connection with the printer 1 is performed using this. 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 only one of the paper feed units PF-1 and PF-2 is connected or both of the paper feed units are connected. Is used to determine Therefore, using the specific bit of the transmission data SID when responding to the discrimination code detecting means S of the printer 1, the connection is detected by a signal of "L" if connected and "H" if not connected.

First, the printer 1 and the paper feeding units PF-1 and PF-
2 is not connected, no matter which select code SEL is transmitted by the printer 1, there is no connection response, so that "H" is always set.
Is detected and can be recognized as not connected.

Next, only the paper feed unit PF-1 is used for the printer 1.
(In this case, the pass unit 11 is inserted), first, the select code SEL transmits "1". As a result, the select code SEL matches the self-determination code. The transmission data SID is sent from PF-1. Here, when the specific bit of the serial clock signal SCKD falls, “L” is output to the printer 1, thereby detecting that the unit PF- 1 and the printer 1 are connected. Subsequently, the printer 1 transmits the select code “0”, but since the selected paper feed unit PF-2 does not exist (that is, is not connected), the printer 1 is set to “H”.
Signal is detected. As a result of the above operation, it is determined that the second-stage paper feed unit PF-2 is not connected, the print process is started ignoring the second-stage paper feed unit, and the fact that the second-stage paper feed unit PF-2 does not exist when the user selects the second-stage. Is displayed on the display of the printer for the first time.

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 inserting the pass unit 11), communication is performed in the same manner as described above. Displays as a mistake.

[0030]

According to the present invention, the discrimination code of the paper feed unit is set in advance to the discrimination code of the lower unit, and when the pass unit is inserted, it is changed to the code for discriminating the upper unit. The discrimination codes of the paper unit (upper) and the other paper supply unit (lower) are clearly separated, and the upper and lower units can be automatically discriminated by the upper and lower detecting means of the printer. Is not recognized, so that the user does not forget to attach the pass unit at the time of installation, thereby not only reducing the burden on the user, but also reducing the cost of the apparatus because it is not necessary to detect whether the pass unit is inserted or not. .

Further, since the presence / absence of the sheet feeding unit, the connection of only one stage, and the connection of both stages can be detected using the upper and lower discrimination code detecting means, a highly reliable image forming apparatus can be detected. Can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an image forming apparatus 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 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: Detector 122a: Photo sensor 122b: Shield plate PF-1: Paper supply unit PF-2: Paper supply unit

Claims (3)

(57) [Claims] An image forming means for printing an image on a sheet; a sheet feeding unit for storing a plurality of sheets and having a feeding mechanism for feeding the sheets one by one; The paper unit and the same paper supply unit are stacked and arranged on the upper and lower tiers, and each paper supply unit is configured to be selectable, and the paper fed from the paper supply mechanism from each selected paper supply unit is described above. In the image forming apparatus configured to be able to be supplied to the image forming unit, each of the sheet feeding units has a lower discrimination code assigned in advance, and each of the sheet feeding units is changed to change the discrimination code to an upper discrimination code. Means, when the discrimination code of the upper unit is changed by the change means in the upper row, and when the change is not carried out in the lower row, the discrimination code of each paper feed unit classified by the change means is respectively set. Inspection An image forming apparatus characterized by including a discrimination code detecting means for determining that the upper or lower and. A conveying roller for guiding the paper to the image forming means between a paper supply port on a lower side of the image forming means and a feeding port of a paper feeding unit disposed immediately below the image forming means. 2. The apparatus according to claim 1, wherein a pass unit is provided, said pass unit is configured to be insertable into said sheet feeding unit, and said discrimination code is changed by inserting said pass unit. Image forming apparatus. 3. The image forming apparatus according to claim 1, wherein an error in installation is detected when the sheet feeding units are stacked on the upper and lower tiers without changing the discrimination code.