JP2003267564A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine the presence of a fitted option cassette with a simple structure. <P>SOLUTION: A CPU 111 determines the presence of the fitted option cassette. If transfer paper sensors 613, 623, 633 detects storage of transfer paper, the CPU 111 determines it as the option cassette having been fitted. If the absence of the transfer paper is detected, the CPU 111 determines it as the option cassette having not been fitted. The CPU 111 stores the results of determination on the fitted option cassette in a nonvolatile storage 118. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming technique for printers, copiers, facsimile machines and the like.

[0002]

2. Description of the Related Art Conventionally, a developing means attaches toner to an electrostatic latent image formed on a photoconductor by an exposing means to form a toner image, the toner image is transferred to a transfer paper, and the transferred toner is transferred. An electrophotographic image forming apparatus is known in which an image is fixed on the transfer paper by a fixing unit. Particularly, as a device capable of forming a color image, a toner image formed on a photoconductor is intermediately transferred. It is known that primary transfer is performed on a medium, and the primary transfer toner image on the intermediate transfer medium is secondarily transferred on a transfer paper.

[0003] A cassette for accommodating transfer paper is usually constructed so as to selectively accommodate one of a plurality of sizes, and in recent years, it has been standardized to meet various demands of users. Often, only one cassette is installed, and multiple cassettes can be optionally installed.

In such an image forming apparatus, a detection means for detecting the presence / absence of an optional cassette is required. Therefore, for example, an optical sensor for detecting the presence / absence of an optional cassette or a loopback wiring is connected to a connector to the apparatus main body. Is provided, and a CPU is provided to determine the detection signal.
Is equipped with a dedicated input port.

[0005]

However, since a sensor is required for each of a plurality of option cassettes, the number of parts is increased. Further, for example, when the option cassette is not used in the image forming apparatus of the specification in which three option cassettes can be mounted,
The three input ports provided in the CPU are wasted.

The present invention has been made in view of the above,
An object of the present invention is to provide an image forming apparatus capable of determining whether or not an optional cassette is attached with a simple configuration.

[0007]

In order to achieve the above object, the present invention according to claim 1 provides a standard cassette for accommodating transfer paper, which is standardly provided in the apparatus main body,
In an image forming apparatus in which an option cassette containing a transfer sheet is attachable to the apparatus main body, a transfer sheet detecting unit is provided in the option cassette and detects whether or not the transfer sheet is contained in the option cassette, When the presence of the transfer sheet is detected by the transfer sheet detecting section, a mounting determining section that determines that the option cassette is mounted in the apparatus main body is provided.

According to this structure, when the presence of the transfer sheet is detected by the transfer sheet detecting means which is disposed in the option cassette and detects whether or not the transfer sheet is accommodated in the option cassette, the option cassette is set as the device. By determining that the optional cassette is attached to the main body, it is not necessary to separately provide a detection unit for detecting attachment of the optional cassette to the main body of the apparatus, and the number of parts constituting the apparatus can be reduced.

Further, when a non-volatile memory having a predetermined storage capacity and the mounting determination means determine that the optional cassette is mounted in the apparatus main body, a storage for storing the fact in the non-volatile memory. You may make it further provide a control means (Claim 2).

According to this structure, when it is determined that the option cassette is mounted in the main body of the apparatus, the fact is stored in the non-volatile memory, so that the mounting of the option cassette is stored in the non-volatile memory. In this state, when the transfer paper detection unit does not detect the presence of the transfer paper, it can be surely determined that the transfer paper stored in the option cassette has been used up, so it is recommended to supplement the transfer paper to the option cassette. It becomes possible to take countermeasures such as.

The mounting determination means further comprises a volatile memory having a predetermined storage capacity, and a storage control means for controlling rewriting of stored data in the volatile memory.
When the power is turned on, it is determined whether or not the optional cassette is attached to the apparatus main body.
When the mounting determination unit determines that the optional cassette is mounted in the apparatus main body, a message to that effect may be stored in the volatile memory (claim 3).

According to this structure, it is determined whether or not the option cassette is attached to the apparatus body when the power is turned on, and when it is determined that the option cassette is attached to the apparatus body, the fact is stored in the volatile memory. By being
Even if the option cassette is newly installed or the option cassette that has been installed in the opposite direction is removed while the power is off, those state changes can be reliably determined.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the configuration of a printer which is an embodiment of an image forming apparatus according to the present invention will be described with reference to FIGS. 1 is a diagram showing the internal configuration of the upper half of the printer, FIG. 2 is a diagram showing the internal configuration of the lower half of the printer, FIG. 3 is a development view of an intermediate transfer belt, and FIG. 4 is an electrical diagram of the printer. It is a block diagram which shows a structure.

This printer forms a full-color image by superposing four color toners of yellow (Y), magenta (M), cyan (C), and black (K), for example, only black (K) toner. Is used to form a monochrome image. In this printer, when a print command signal including an image signal is given to the main control unit 100 from an external device (for example, a personal computer, PC in this embodiment) 200 such as a host computer, the main control unit 100
The engine control unit 110 controls each unit of the engine unit 1 in response to a control signal from the transfer unit 4 to transfer an image corresponding to the image signal to the transfer sheet 4 conveyed from the transfer sheet storage unit 3 provided in the lower portion of the apparatus main body 2. Is printed out.

The engine unit 1 includes the transfer paper container 3
And a photoconductor unit 10, a rotary developing unit 20, an intermediate transfer unit 30, a fixing unit 40,
An exposure unit 50 is provided. This photoconductor unit 1
Reference numeral 0 is a photoconductor 11, a charging unit 12, and a cleaning unit 1.
3, the rotary developing unit 20 includes a yellow developing unit 2Y containing yellow toner, a magenta developing unit 2M containing magenta toner, a cyan developing unit 2C containing cyan toner, and a black containing black toner. The intermediate transfer unit 30 includes a developing unit 2K and the like, and the intermediate transfer unit 30 includes an intermediate transfer belt 31, a vertical synchronization sensor 32, a belt cleaner 33, and a gate roller pair 3.
4, a secondary transfer roller 35, a photoconductor driving motor 36, and the like. The above seven units 10, 2Y, 2M,
2C, 2K, 30 and 40 are configured to be attachable to and detachable from the apparatus main body 2, respectively.

The photoconductor 11 of the photoconductor unit 10 includes the seven units 10, 2Y, 2M, 2C, 2K, 30,
In the state in which 40 is attached to the apparatus main body 2, it is rotated in the direction of arrow 5 by the photoconductor driving motor 36. Around the photoconductor 11 along the rotation direction 5, the charging unit 1
2. A rotary developing unit 20 and a cleaning unit 13 are arranged.

The charging unit 12 is provided with a wire electrode to which a high voltage of a predetermined level is applied, and uniformly charges the outer peripheral surface of the photoconductor 11 by, for example, corona discharge. The cleaning unit 13 is disposed on the upstream side of the charging unit 12 in the rotation direction 5 of the photoconductor 11 and remains on the outer peripheral surface of the photoconductor 11 after the primary transfer of the toner image from the photoconductor 11 to the intermediate transfer belt 31. The surface of the photoconductor 11 is cleaned by scraping off the existing toner.

The exposure unit 50 is reflected by a laser light source 51 formed of, for example, a semiconductor laser, a polygon mirror 52 that reflects the laser light from the laser light source 51, a polygon motor 53 that rotationally drives the polygon mirror 52, and a polygon mirror 52. Lens unit 5 for focusing the laser light
4, a plurality of reflection mirrors 55, a horizontal synchronization sensor 56, etc. are provided. Is reflected by the polygon mirror 52,
The laser beam 57 emitted through the lens unit 54 and the reflection mirror 55 scans the surface of the photoconductor 11 in the main scanning direction (direction perpendicular to the paper surface of FIG. 1), and the static light corresponding to the image signal is obtained. An electrostatic latent image is formed on the surface of the photoconductor 11.
At this time, the horizontal synchronization sensor 56 obtains a synchronization signal in the main scanning direction, that is, a horizontal synchronization signal.

The polygon motor 53 is a polygon mirror 5.
2 is a preset rotation speed, for example 30,000 rp
It is driven to rotate at a high speed of m (rotation / minute) and outputs a ready signal when the rotation speed of the polygon mirror 52 reaches a set value. As described above, since the rotation speed of the polygon motor 53 is high, it takes a predetermined time from the start of driving the polygon motor 53 to the output of the ready signal. The exposure unit 50 has a function as an exposure unit.

The rotary developing section 20 adheres the toner of each color to the electrostatic latent image and develops it. The yellow developing unit 2Y, the magenta developing unit 2M, the cyan developing unit 2C, and the black developing unit 2K of the rotary developing unit 20 are rotatably provided around the axis, and these developing units 2Y, 2M, 2C and 2K are predetermined. It is movably arranged at the plurality of positions, and is selectively arranged at the contact position and the separated position with respect to the photoconductor 11. Then, a developing bias in which a direct current component or a direct current component and an alternating current component are superimposed is applied, and the toner of the color is attached to the surface of the photoconductor 11 from the developing unit in the contact position with respect to the photoconductor 11. This rotary development unit 2
0 has a function as a developing means.

Intermediate transfer belt 3 of intermediate transfer unit 30
1 is wound around a tension roller 31A, a drive roller 31B, a tension roller 31C and a driven roller 31D. As shown in FIG. 3, the intermediate transfer belt 31 is an endless belt formed by joining substantially rectangular sheet bodies at a joint 71. In FIG. 3, an arrow 72 indicates a rotation driving direction, and an arrow 73 indicates a rotation axis direction.

The intermediate transfer belt 31 has a rotational axis direction of 7
3 has a protruding portion 74 provided on one end side (upper side in FIG. 3) of 3, and has a transfer inhibition area 75 and a transfer permission area 76. The transfer prohibited area 75 is set in a range of predetermined dimensions on both sides of the seam 71 from one end to the other end in the rotation axis direction 73. Transfer permission area 76
Is a region other than the transfer inhibition region 75 and is set to a rectangular region excluding one end and the other end in the rotation axis direction 73, and the toner image is primarily transferred to the transfer permission region 76. The transfer permission area 76 has a size larger than the A3 size in the long side direction in the rotation driving direction 72, and the A3 size toner image 77 in the long side direction in the rotation driving direction 72 can be transferred.

The tension roller 31A is for ensuring that the intermediate transfer belt 31 is brought into contact with the photosensitive member 11. The photoconductor 11 is in contact with the intermediate transfer belt 31 immediately downstream of the tension roller 31A in the rotational driving direction 72 of the intermediate transfer belt 31, and the contact position is set in the primary transfer portion 14. The drive roller 31B is rotationally driven together with the photoconductor 11 by the photoconductor drive motor 36.

The vertical synchronization sensor 32 is composed of, for example, a photo interrupter having a light emitting portion (for example, LED) and a light receiving portion (for example, photodiode) arranged to face each other, and one end side of the rotating intermediate transfer belt 31 in the rotation axis direction 73. And detects the passage of the protrusion 74 and outputs a detection signal. The detection signal output from the vertical synchronization sensor 32 is used as a vertical synchronization signal that serves as a reference for image formation control by the engine control unit 110. The vertical synchronization sensor 32 is arranged in the vicinity of the driven roller 31D, whereby the intermediate transfer belt 3 is
It is possible to reduce the influence of the bending and the swinging of No. 1 and to stably detect the protruding portion 74.

The belt cleaner 33 is in contact with the intermediate transfer belt 31 by the cleaner separation clutch (see FIG. 1).
The middle and solid lines) and the separated state (broken line in FIG. 1) are switchably arranged to scrape off the residual toner on the intermediate transfer belt 31 in the contact state. The contact and separation of the belt cleaner 33 is performed on the transfer prohibited area 75 of the intermediate transfer belt 31. The gate roller pair 34 is rotationally driven by the driving force of the transport system driving motor 66 being transmitted when the gate clutch is turned on.

The secondary transfer roller 35 is switched between the contact state (solid line in FIG. 1) and the separated state (broken line in FIG. 1) with respect to the intermediate transfer belt 31 by the secondary transfer roller separation clutch. A predetermined secondary transfer bias is applied to the secondary transfer roller 35 in a state of being in contact with the intermediate transfer belt 31, and the toner image on the intermediate transfer belt 31 is transferred onto the transfer sheet 4 while conveying the transfer sheet 4. The second transfer is performed, and the contact position is set in the secondary transfer portion 37.

A bias applying member (not shown) is in contact with the intermediate transfer belt 31, and a predetermined primary transfer bias is applied to this bias applying member, and the toner image on the photoconductor 11 is applied by this primary transfer bias. Are primarily transferred to the intermediate transfer belt 31.

The fixing unit 40 comprises a heating roller 41 and a pressure roller 42, and the transfer paper 4 is made up of the rollers 41 and 42.
The toner on the transfer paper 4 is heated and melted to be fixed on the transfer paper 4 while being conveyed, and has a function as a fixing unit.

The transfer paper accommodating portion 3 is equipped with a standard cassette 60 for accommodating the transfer paper 4 as standard equipment, and is constructed so that four optional cassettes can be installed. In this embodiment, FIG. As shown, three option cassettes, a first option cassette 61, a second option cassette 62, and a third option cassette 63, are installed.

At the right end of the standard cassette 60, a pickup roller 601 for taking out the uppermost transfer sheet 4 of the stacked transfer sheet bundle is arranged, and immediately above the pickup roller 601.
A feed roller pair 602 is arranged. A transfer paper sensor 603 for detecting the presence or absence of the transfer paper 4 accommodated therein is arranged immediately to the left of the pickup roller 601.

First to third optional cassettes 61 to 63
Is configured similarly to the standard cassette 60. That is, the first option cassette 61 includes a pickup roller 611, a feed roller pair 612, a first option transfer paper sensor 613, and a second option cassette 62.
Is a pickup roller 621, a feed roller pair 62
2, a second option transfer paper sensor 623, a third option cassette 63, a pickup roller 631,
A pair of feed rollers 632 and a third optional transfer sheet sensor 633 are provided.

A gate roller pair 34 and a secondary transfer roller 35 are arranged upward from the feed roller pair 602, and the conveying roller pair 6 is sandwiched by the fixing unit 40.
4, a pair of discharge rollers 65 are provided, and a transport path for the transfer paper 4 (indicated by a chain line in FIG. 1) is formed by these.

Pickup rollers 601, 611, 62
1, 631, feed roller pair 602, 612, 62
2, 632, gate roller pair 34, secondary transfer roller 3
5, the heating roller 41 of the fixing unit 40, the conveyance roller pair 64, and the discharge roller pair 65 are connected to the same conveyance system driving motor 66 via a driving force transmission mechanism. The pickup rollers 601, 611, 62
1, 631 is driven by the pickup clutch being turned on, and the feed roller pairs 602, 612, 622, 632 are rotationally driven by transmitting the driving force of the transport system driving motor 66, respectively, being turned on.

Transfer paper sensors 603, 613, 623, 6
Reference numerals 33 denote rotating pieces that are rotated by the stacked transfer papers 4 (shown by broken lines and solid lines in FIG. 2) and photo pieces that detect the rotating pieces at the rotating position when the transfer papers 4 are not present. The detection signals are sent to the engine control unit 110.

Pickup rollers 601, 611, 62
1, 631, feed roller pair 602, 612, 62
2, 632, gate roller pair 34, transport roller pair 64,
The discharge roller pair 65 has a function as a transfer unit for the transfer paper 4.

In FIG. 4, the main controller 100 is a CPU
101, an interface 102 for exchanging control signals between the PC 200, and the interface 102
An image memory 103 for storing an image signal given from the PC 200 via the. CPU 101
When a print command signal including an image signal is received from the PC 200 via the interface 102, the engine unit 1
The job data is converted into job data in a format suitable for the operation instruction, and is sent to the engine control unit 110.

The engine control unit 110 includes a CPU 111,
The ROM 112 and the RAM 113 are provided. ROM
Reference numeral 112 stores a control program of the CPU 111, and the RAM 113 temporarily stores control data of the engine unit 1, a calculation result by the CPU 111, and the like.

The CPU 111 receives a vertical synchronizing signal Vsync from the vertical synchronizing sensor 32, a horizontal synchronizing signal Hsync from the horizontal synchronizing sensor 56, and the transfer paper sensors 603, 613 as input signals from the engine unit 1, for example.
The detection signal is received from 623 and 633. And CP
The U111 controls the operation of each unit of the engine unit 1 based on these input signals and the control program.

That is, the CPU 111 sends a control signal to the motor drive circuit 114 for driving the photoconductor drive motor 36 to synchronously rotate the photoconductor 11 and the intermediate transfer belt 31. In addition, a control signal is sent to the motor drive circuit 115 that drives the transport system drive motor 66, and a control signal is sent to a drive circuit (not shown) that drives each pickup clutch and each feed clutch to transfer paper storage. The transfer of the transfer paper 4 from the unit 3 is controlled.
The transfer paper 4 is conveyed at the same speed as the peripheral speed of the intermediate transfer belt 31.

Further, the CPU 111 sends a control signal to the transfer bias generating circuit 116 which generates a transfer bias to apply the primary transfer bias to the bias applying member and the secondary transfer bias to the secondary transfer roller 35. Control. Further, the CPU 111 sends a control signal to the motor drive circuit 117 that drives the polygon motor 53 to control the driving of the polygon motor 53. Further, the CPU 111 sends a control signal to a separation clutch driving circuit (not shown) that drives each separation clutch, and controls separation and contact of the belt cleaner 33 and the secondary transfer roller 35 with respect to the intermediate transfer belt 31. . Also, C
The PU 111 receives, for example, the operation content of the operation keys of the operation display panel 7 arranged on the surface of the apparatus main body 2, and controls the display content of the display unit including, for example, a liquid crystal display.

Further, the CPU 111 judges whether or not an optional cassette is mounted on the apparatus main body 2, and the first, second and third optional transfer paper sensors 613, 613 are used.
When the presence of transfer paper is detected by 623 and 633, it is determined that the first, second and third option cassettes 61, 62 and 63 are mounted. In addition, the CPU 111 determines whether or not the option cassette is installed by using, for example, EEP.
The data is stored in the non-volatile memory 118 composed of ROM and MRAM. In this case, the nonvolatile memory 118 contains
Data is written by the CPU 111 so that it can be distinguished whether or not the presence / absence of mounting is undetermined or determined.

In this embodiment, the printer is set so that four option cassettes can be mounted, and the CPU 111 is provided with an input port for inputting a detection signal from the fourth option transfer paper sensor. However, this input port is an empty port in this embodiment. The signal level of this empty port is the first, second and third option transfer paper sensors 613, 62.
3 and 633 are set to the same level as the signal level when detecting the absence of transfer paper. For example, when the transfer sheet is set to the high level signal and the transfer sheet is set to the low level signal, it is determined that the empty port is pulled down to the low level signal and the fourth option cassette is not mounted. . By setting such a signal level, the CPU 111 can accurately determine whether the option cassette is mounted. The specific determination procedure by the CPU 111 will be described later.

The first, second and third optional transfer sheet sensors 613, 623 and 633 correspond to the transfer sheet detecting means, and C
PU111 corresponds to a mounting determination unit.

Next, the operation of the printer will be described with reference to FIG. FIG. 5 is a timing chart showing the change over time of the state of each part of the engine unit 1.

When a print command signal including an image signal is given from the PC 200 to the main control unit 100, the main control unit 10
The engine control unit 110 starts the operation of each unit of the engine unit 1 in response to the control signal from 0. At this time, if the sizes of the transfer papers 4 loaded in the standard cassette 60 and the optional cassettes 61, 62, and 63 do not match the sizes instructed by the print command signal, the operation display panel 7 is used to replace the cassette. Is displayed.

A transfer paper size setting dial (not shown) is provided in each of the cassettes 60 to 63, and the CPU 111 causes each of the cassettes 6 to receive a signal from the dial.
It is possible to determine the size of the transfer paper accommodated in 0 to 63. Here, as an example, it is assumed that the transfer paper 4 of the size designated by the print command signal is accommodated in the first option cassette 61.

First, at time t1, the transport system drive motor 66 is driven.
Is turned on. Subsequently, when the ready signal is output from the transport system driving motor 66 at time t2, the driving of the photoconductor driving motor 36 is started, the intermediate transfer belt 31 is driven at a predetermined peripheral speed S1, and the vertical synchronization signal is output. The Vsync is periodically output and the driving of the polygon motor 53 is started. Then, when the ready signal is output from the polygon motor 53 at time t3, it is effectively accepted from the next vertical synchronization signal Vsync, the surface of the photoconductor 11 is uniformly charged by the charging unit 12, and the surface of the photoconductor 11 is received. , An electrostatic latent image corresponding to the image signal is formed by the laser beam 57 from the exposure unit 50, and the electrostatic latent image is developed by the rotary developing unit 20 to form a toner image. Primary transfer is performed on the intermediate transfer belt 31 in the next transfer unit 14.

That is, the intermediate transfer belt 31 is rotated by the driving of the photoconductor driving motor 36, and the times t4, t5, and
The vertical synchronization signal Vsync is output at t6 and t7, respectively. A predetermined time T from the falling edge of each vertical synchronization signal Vsync
After one time, the image request signal Vreq is output, and upon the falling of the image request signal Vreq, the formation of the electrostatic latent image corresponding to the image signal is started and the developing bias is turned on.

Then, the developing units of the rotary developing section 20 are switched at times t4, t5, t6, and t7, and toner images of respective colors are formed on the photoconductor 11 and sequentially primary-transferred onto the intermediate transfer belt 31. It During this time, the secondary transfer roller 35 is separated from the intermediate transfer belt 31, so that the toner images of the respective colors are superposed on the intermediate transfer belt 31. The developing bias is at time t4, t5, t
It is turned off after a predetermined time T2, which is predetermined by the transfer paper size, from the falling point of each vertical synchronization signal Vsync of 6 and t7. As a result, the toner images Y, C, M and K are superimposed on the transfer permission area 76 of the intermediate transfer belt 31.

On the other hand, the uppermost transfer sheet 4 of the transfer sheet bundle loaded in the option cassette 61 is taken out by the pickup roller 611, conveyed by the feed roller pair 612 and the feed roller pair 602 at a predetermined speed, and the gate roller pair. Nip 34. Then, the gate clutch is turned on at the same timing as the toner image on the intermediate transfer belt 31, and the gate roller pair 34 to
The transfer paper 4 is conveyed toward the next transfer unit 37.

After a predetermined time from the time t8 when the vertical synchronizing signal Vsync falls, the separation clutch for the secondary transfer roller is turned on, the secondary transfer roller 35 contacts the intermediate transfer belt 31, and Then, the application of the secondary transfer bias from the transfer bias generation circuit 116 to the secondary transfer roller 35 is turned on at a time t9 after a predetermined time from the time t8. As a result, the color toner image in which the toner images Y, C, M, and K that have been primarily transferred to the transfer permission area 76 of the intermediate transfer belt 31 are superimposed is transferred to the transfer paper 4.

The gate clutch is turned off after the transfer paper 4 is carried out, and the application time T3 of the secondary transfer bias is preset according to the size of the transfer paper 4. After the application of the secondary transfer bias is turned off, the separation clutch for the secondary transfer roller is turned on, and the secondary transfer roller 35 is separated from the intermediate transfer belt 31. Then, in the fixing unit 40, the toner image is fixed on the transfer paper 4 while the transfer paper 4 is being conveyed. The transfer paper 4 is further transported by the transport roller pair 64, and is discharged to the paper discharge unit 6 by the discharge roller pair 65.

After the image formation, if the next print command signal is not input, the charging unit 12 is turned off at time t10, which is the falling point of the vertical synchronizing signal Vsync, and the primary transfer bias is passed after a predetermined time from time t10. Is turned off, then
At a time t11, which is a predetermined time after the time t10, the photoconductor drive motor 36 starts decelerating, and at the time t12 when the photoconductor drive motor 36 stops, the laser light source 51 is turned off, and the transport system drive motor 66 is provided. Is turned off. The polygon motor 53 is turned off at time t13, which is a preset standby time T4 (for example, T4 = 30 seconds in the present embodiment) from time t12.

Next, with reference to FIG. 6 and FIG. 7, the procedure for determining the mounting of the option cassette will be described. FIG. 6 is a flowchart showing an operation procedure executed when the power is turned on, and FIG. 7 is a flowchart showing an operation procedure executed at a predetermined sampling cycle.

In FIG. 6, first, the nonvolatile memory 11
The storage content of No. 8 is fetched (# 10), and it is determined whether or not the option cassette installation determination has been completed (# 1).
2). If it is determined (YES in # 12),
This routine ends.

On the other hand, if it is determined that the option cassette is not mounted (NO in # 12), the detection signals of all the option transfer paper sensors are fetched (# 14), and the option cassette is installed depending on the presence or absence of the transfer paper. Presence / absence is determined (# 16), and the determination result is the nonvolatile memory 118.
(# 18), and this routine ends.

In the present embodiment, detection signals with transfer paper are input from the first, second and third option transfer paper sensors 613, 623, 633, and detection signals with transfer paper are sent from the fourth option transfer paper sensor. Because it is not entered, the first,
It is stored in the non-volatile memory 118 that the second and third option cassettes 61, 62, 63 are mounted and the fourth option cassette is not mounted.

Next, in FIG. 7, the stored contents of the non-volatile memory 118 are first taken in (# 20), and it is judged whether or not the option cassette is installed (# 2).
2) If not attached (NO in # 22), this routine ends.

If the optional cassette is installed (YES in # 22), the detection signal of the transfer paper sensor corresponding to the installed optional cassette is fetched (# 2).
4). Here, the detection signals from the first, second, and third option transfer paper sensors 613, 623, 633 are fetched.

Then, it is judged whether or not all the transfer sheets are present (# 26), and if all the transfer sheets are present (YE in # 26).
S), this routine is ended, and if there is a sensor without a transfer sheet (NO in # 26), a message prompting the supply of the transfer sheet 4 to the option cassette corresponding to the transfer sheet sensor is displayed on the operation display panel 7. Is displayed as a warning (# 28),
This routine ends.

As described above, according to the present embodiment, when the transfer sheet 4 is detected by the transfer sheet sensors 613, 623 and 633 which detect the presence or absence of the transfer sheet in the optional cassettes 61 to 63, Optional cassette 61-
Since it is determined that 63 is attached to the apparatus main body 2, it is not necessary to separately provide a detection unit for detecting whether or not the option cassette is attached, and the number of parts can be reduced. Since a sensor for detecting the presence / absence of the transfer sheet is indispensable from the viewpoint of usability, it can also be used for determining whether or not the optional cassette is mounted.

Further, according to the present embodiment, since the result of determination of the mounting of the optional cassette is stored in the non-volatile memory 118, the PC 200 can confirm the mounting status of the optional cassette.

The present invention is not limited to the above embodiment, and various changes can be made to the above without departing from the spirit of the invention. For example, the following modifications are possible. (1) to (4) can be adopted.

(1) In the above embodiment, the determination result of the option cassette is stored in the non-volatile memory 118, but the present invention is not limited to this, and may be stored in the RAM 113.
FIG. 8 is a flowchart showing a different operation procedure when the power is turned on. In FIG. 8, first, the detection signals of all the optional transfer paper sensors are fetched (# 30), the presence or absence of the optional cassette is determined by the presence or absence of the transfer paper (# 32), and the determination result is stored in the RAM 113. Then (# 34), the process ends.

As described above, by always determining whether or not the optional cassette is mounted when the power is turned on, the optional cassette is newly mounted after the lapse of time from the start of use of the apparatus, or conversely, it is initially mounted. Even if the option cassette is removed, the change in the state can be reliably identified. In this case, the non-volatile memory 118 becomes unnecessary.

(2) The procedure for determining the mounting of the option cassette is not limited to the above embodiment. For example, when the third option cassette 63 is detected by the option transfer paper sensor distant from the standard cassette 60 and the detection signal of the third transfer paper sensor 633 determines that the third option cassette 63 is installed, for example, the second option It may be determined that the cassette 62 and the first option cassette 61 are also mounted.

(3) In the above embodiment, the printer is provided with three optional cassettes, but the present invention is not limited to this, and two or less or four or more optional cassettes may be used.

(4) In the above embodiment, a printer that prints an image provided by an external device 200 such as a host computer on a transfer paper is used for explanation, but the present invention is not limited to this, and a copying machine or It can be applied to a general electrophotographic image forming apparatus including a facsimile apparatus and the like.

[0069]

As described above, according to the first aspect of the present invention, when the transfer sheet detecting means for detecting whether or not the transfer sheet is accommodated in the option cassette is detected as the presence of the transfer sheet, the option Since it is determined that the cassette is attached to the apparatus main body, it is not necessary to separately provide a detection means for detecting the attachment of the optional cassette to the apparatus main body, and the number of parts constituting the apparatus can be reduced. .

According to the second aspect of the present invention, when it is determined that the optional cassette is mounted in the apparatus main body, the fact is stored in the non-volatile memory. If the presence of the transfer paper is not detected while it is stored in the non-volatile memory, it can be reliably determined that the transfer paper stored in the option cassette has been used up, and as a result, the transfer paper to the option cassette can be determined. It is possible to take countermeasures such as urging replenishment of.

According to the third aspect of the present invention, when the power is turned on, it is determined whether or not the option cassette is attached to the main body of the apparatus, and if it is determined that the option cassette is attached to the main body of the apparatus, a message to that effect is given. Since it is stored in the volatile memory, even if a new option cassette is installed or the option cassette that was installed in the opposite is removed while the power is off, those state changes will be ensured. Can be determined.

[Brief description of drawings]

FIG. 1 is a diagram showing an internal configuration of an upper half portion of a printer which is an embodiment of an image forming apparatus according to the present invention.

FIG. 2 is a diagram showing an internal configuration of a lower half portion of the printer.

FIG. 3 is a development view of an intermediate transfer belt.

FIG. 4 is a block diagram showing an electrical configuration of the printer.

FIG. 5 is a timing chart showing changes over time in states of various parts of the engine unit.

FIG. 6 is a flowchart showing an operation procedure executed when the power is turned on.

FIG. 7 is a flowchart showing an operation procedure executed at a predetermined sampling cycle.

FIG. 8 is a flowchart showing a different operation procedure when the power is turned on.

[Explanation of symbols]

2 Apparatus main body 60 Standard cassette 61 First option cassette 62 Second option cassette 63 Third option cassette 613 First option transfer paper sensor (transfer paper detecting means) 623 Second option transfer paper sensor (transfer paper detecting means) 633 Third Optional transfer paper sensor (transfer paper detection means) 110 Engine control unit 111 CPU (mounting determination means) 113 RAM (volatile memory) 118 Non-volatile memory

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Claims (3)

[Claims] 1. An image forming apparatus in which, in addition to a standard cassette for accommodating transfer paper, which is standardly installed in the apparatus main body, an optional cassette for accommodating transfer paper is attachable to the apparatus main body, A transfer sheet detection unit that is provided and detects whether or not the transfer sheet is accommodated in the option cassette, and the presence of the transfer sheet is detected by the transfer sheet detection unit,
An image forming apparatus comprising: an attachment determining unit that determines that the option cassette is attached to the apparatus main body. 2. A non-volatile memory having a predetermined storage capacity, and a storage for storing the fact in the non-volatile memory when the mounting determination unit determines that the option cassette is mounted in the apparatus main body. The image forming apparatus according to claim 1, further comprising a control unit. 3. A volatile memory having a predetermined storage capacity, and a storage control means for controlling the rewriting of the stored data of the volatile memory, wherein the mounting determination means is provided for the optional cassette when the power is turned on. When it is determined by the attachment determining unit that the optional cassette is attached to the device body, the storage control unit determines whether or not the device cassette is attached to the volatile memory. The image forming apparatus according to claim 1, wherein the image forming apparatus is stored.