JPH0412507Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an image forming apparatus in which a unit in which a plurality of image forming parts such as photoreceptors are combined is detachably attached to the main body of the apparatus.

[Prior art]

Conventionally, for example, in an electrophotographic copying machine, in order to use the device for a long period of time, it is necessary to replace consumable parts such as the photosensitive drum, clean the developing device, charger, etc., replenish the developer, and dispose of waste toner. It was necessary to do this regularly. This kind of work is done by professional maintenance personnel, and because the work is complicated,
In particular, periodic inspection of small copying machines, of which there are many on the market, is actually difficult.

Therefore, in order to simplify the maintenance and inspection work, for example, the photosensitive tram, the developer, and the cleaning device are integrated into a unit, and the maintenance and inspection work is performed by replacing this unit.

In image forming apparatuses such as those described above that replace units containing conventional developing devices, the developer in the developing device of a new unit or a unit that has not been used for a long period of time may harden or become uneven. There's something I'm doing. For this reason, when using the above-mentioned unit, it is necessary to perform the stirring operation for a predetermined period of time when the power is turned on. Further, along with this stirring operation, the photoreceptor drum and the like are also rotated.

[Problems with conventional technology]

However, as mentioned above, if the developing unit etc. always rotates when the power is turned on, or if the power is simply turned on and off without replacing the image forming unit (for example, a paper jam occurs and the power switch is turned off). If this process is performed and printing is restarted, the developer, etc. will be rotated again, delaying the image forming operation and causing inconvenience to the user.

[Purpose of invention]

In view of the above-mentioned conventional drawbacks, the present invention has been developed to
To provide an image forming apparatus capable of determining whether a unit has been replaced and efficiently performing an image forming operation without rotating a developer or the like when the unit has not been replaced.

[Key points of the idea]

In order to achieve the above object, the present invention provides an image forming apparatus in which an image forming unit including at least a developing device is removably attached to an apparatus main body, and an initial operation of driving at least the developing device is performed for a predetermined period of time when the device is powered on. , comprising a determining means for determining that the unit has been replaced while the main power supply of the apparatus is cut off, and varying the predetermined time for executing the initial operation depending on the determination result of the determining means. .

[Example of idea]

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a perspective view of an image forming unit, and FIG. 3 is a perspective view of an image forming apparatus using the image forming unit shown in FIG.

In the figure, reference numeral 1 denotes a main body of an image forming apparatus that performs printing using an electrophotographic process, and the main body 1 is configured so that an image forming unit 2 can be replaced. The image forming unit 2 has a photosensitive drum 3, and a developing device and a cleaning device (not shown) are disposed around the photosensitive drum 3, and these devices are integrated into a unit. By simply replacing the image forming unit 2, the photosensitive drum 3 can be replaced, the developer in the developing device can be replenished, or the waste toner stored in the cleaning device can be disposed of at the same time.

On the side of the image forming unit 2, there is a
A driven gear 5 is provided coaxially with the rotating shaft 4 of the photosensitive drum 3 inside the main body 1, and when the image forming unit 2 is attached to the main body 1, the driven gear 5 is connected to a drive gear (not shown) inside the main body 1. It has an engaging structure. The driven gear 5 is rotated by the drive of the driving gear, thereby the photosensitive drum 3 is rotated, and an agitation mechanism (not shown) in the developing unit that is linked to the driven gear 5 is operated.

On the surface of the driven gear 5, a plurality of circular marks 5a and one oval mark 5 are provided as a code to distinguish the image forming unit 2 from other units.
b is given. These marks 5a and 5
b are provided on the same circumference around the rotating shaft 4,
Moreover, the marks 5a are provided on the circumference at the same angular intervals. Then, a large number of combinations are created depending on whether or not the mark 5a is at the set position,
The combination is used as a code to distinguish the image forming unit 2. In this embodiment, the mark 5a is provided at 8 positions, and 256 combinations are created depending on the presence or absence of the mark 5a at the set position.As a result, up to 256 image forming units can be manufactured at each unit during unit manufacture. set to be distinguishable.

A reflective photo sensor 6 is provided in the image forming apparatus main body 1 at a position facing the marks 5a and 5b of the driven gear 5 in the image forming unit 2. A light emitting element (not shown) provided close to the sensor 6 emits light toward the driven gear 5, and the photo sensor 6 receives the reflected light. In this case, the marks 5a and 5b are formed of a light-reflecting material, and their surroundings are painted with a color that absorbs light, such as black. Therefore, when the driven gear rotates at a constant speed by driving the driving gear, the light emitted from the light emitting element is reflected by the marks 5a and 5b, and the other parts are absorbed. Thereby, the light reception signal of the photo sensor 6 is outputted to a serial/parallel conversion circuit, which will be described later.

A circuit as shown in FIG. 1 is provided in the image forming apparatus main body 1 having the external mechanism as described above. This circuit consists of CPU (central processing unit) 7, ROM
(read-on memory) 8, RAM (random access memory) 9, the above-mentioned serial/parallel conversion circuit (hereinafter referred to as S/P conversion circuit) 10, and the like.

The driven gear 5 described above is rotated by the drive gear 12 transmitting the driving force of the motor 11. S/P
The conversion circuit 10 is a circuit that serially inputs 8-bit data from the aforementioned photo sensor 6 and outputs it in parallel. Further, a control program for the image forming apparatus of this embodiment is stored in the ROM 8, and the CPU 7 performs image forming control by outputting program data sequentially read from the ROM 8 to the CPU 7.

This CPU 7 also receives a parallel signal from the above-mentioned S/P conversion circuit 10, and also receives a print signal from a print switch (not shown). It also outputs a lifespan display signal and a unit unusable display signal, which will be described later. In addition to these input/output signals, the CPU 7 exchanges data with the RAM 9.

The RAM 9 has areas for storing two types of data, as shown in FIG. 4 as memory M ₁ and memory M ₂ . The code of the previously installed image forming unit is registered in the storage area of this memory _M1 . This storage area (memory
_M1 ) consists of areas for registering 10 types of 8-bit data. Further, the memory _M2 has a counter area corresponding to each code of the memory _M1 mentioned above, and is a part for storing unit codes and corresponding counter values.

Further, a power supply voltage V is inputted to this RAM 9 from a power supply input terminal 13 via a resistor R and a diode _D1 . The power supply voltage V is also input to the CPU 7 from the power input terminal 13 via the resistor R. This power source (voltage V) is a power source whose supply is stopped when a power switch (not shown) of the image forming apparatus of this embodiment is turned off. For this reason, a battery 14 is connected to the RAM 9 via a diode _D2 so that the data in the RAM 9 is retained even when the power switch is turned off.

The operation of the image forming apparatus of this embodiment having the above-described structure will be explained below according to the flowchart shown in FIG.

First, when the aforementioned power switch is turned on (step ST1 is YES), a detector (not shown) determines whether the image forming unit 2 is attached to the image forming apparatus main body 1 (step ST2). While the image forming unit 2 is not installed, the above judgment (steps ST1 and ST2) is repeated, but when the image forming unit 2 is installed (step ST2 is Y),
The aforementioned motor 11 is driven to rotate the photosensitive drum 3 (step ST3).

Due to this rotation of the photosensitive drum 3, the photo sensor 6 sequentially outputs code data to the S/P conversion circuit 10 in accordance with the reflected light (light reception signal) from the mark 5a as described above. When this 8-bit code data is input to the S/P conversion circuit 10 (when the photosensitive drum 3 rotates once), this 8-bit data is
Supply to CPU7 in parallel. RAM for CPU7
It is determined whether memory _M1 in 9 is empty (step ST4). Here, if the memory _M1 is empty, this 8-bit code is registered at address "0" of the memory _M1 (step ST5). Furthermore, a counter area corresponding to this code is set in memory _M2 (step ST6).

On the other hand, if memory _M1 is not empty (step
ST4 is NO), the input code data is in RAM
It is determined whether the code data is pre-registered in the memory _M1 of the STEP 9 (step ST7). At this point, if the input code data has not yet been registered in memory _M1 , it is determined whether there is a registration area in memory _M1 to register this code data (step
ST8) If there is a registration area, all code data registered in memory _M1 up to this time is shifted by +1 address. (Step ST9). For example, in FIG. 4, when code data is registered up to address 5 of memory _M1 , the code data registered at address "5" is shifted to address "6" as shown by the arrow, and ”
Similarly, the code data registered in is shifted to addresses "1" to "4". In this way, the registration area at address "0" is cleared, and the registration area at address "0" of this memory _M1 is opened in the same way as described above.
Write the new code data input to CPU7,
A counter area is also set in the corresponding memory _M2 (steps ST5 and ST6). Also, the address of the counter area set in memory _M2 is
It may be the same address as M ₁ , but
They do not necessarily have to be the same address as long as the CPU 7 can control the corresponding addresses so that they can be accessed.

On the other hand, if the code data input to CPU 7 is already registered in memory _M1 (step
ST7 is Y), that is, the image forming unit 2 having this code data in the image forming apparatus main body 1 is 1
If the code data has been used once or more than once, determine whether the input code data is registered at address “0” of memory _M1 (step
ST10). That is, as will be described later, each time code data is input in response to attachment/detachment of the image forming unit 2 or power on, the code data of that unit is re-registered at address "0" of the memory _M1 , and is stored until then. Since the address of the code data that was input is sequentially backward (shifted), the address of the input code data is checked. For example, if the address A in the memory _M1 of the code data input here is not "0", this means that the image forming unit 2 having this code data was not used during the previous image forming operation, or there was a paper jam, etc. This is not the case when the power is turned off. Therefore, when using such an image forming unit 2 (step ST10 is N), the motor 11 is driven and the photosensitive drum 3 is turned off for 60 seconds.
(Step ST11). Through this process, the photoreceptor drum 3 and a stirring roll (not shown) in the developing device also rotate.

Furthermore, the same code data at address A of the memory _M1 where the code data input to the CPU 7 as described above is registered is deleted (step
ST12). Through this process, the code data at address A is erased, and the code data at addresses smaller than the erased address A are shifted in the same way as in the above process (step ST9), (step ST13),
The input code data (erased code data) is re-registered at address "0" of the vacant memory _M1 (step ST14).

Further, when the input code data is registered at address "0" in the memory _M1 (step ST10 is Y), the image forming unit 2 having this code data was used last time, or the image forming unit 2 has been used due to a paper jam, etc. While using the same image forming unit,
If the power is simply turned off once, the above process (step 11) is not performed, and the next process (step 11) is not performed.
Proceed to ST15). Along with this re-registration, the counter area corresponding to this code data in memory _M2 is made accessible (step ST15).

After setting the memories M ₁ and M ₂ in the RAM 9 to the new setting state in this way, it is determined whether a print signal is input (step ST16). While this print signal is not input to the CPU 7, it is determined whether the image forming unit 2 is attached or detached or the power switch is turned off (step 17), and if the above operation is being performed (step ST17 is Y), the determination is made again. Return to (step ST1) and re-execute the process.

On the other hand, when the print signal is input to the CPU 7 (Y in step ST16), the data in the counter area in memory _M2 corresponding to the code data set to address "0" mentioned above is incremented by 1 (step ST16 is Y).
ST18), it is determined whether the data in this counter area has reached a predetermined value (whether a carry signal has been output) (ST19). This predetermined value is a value common to all counter areas, and the CPU 7 constantly monitors this value. This predetermined value is set as the number of copies in the unit life of each image forming unit 2. Therefore, while this judgment (step ST19) is N, steps ST16→ST18→ST19 can be repeated and the copy operation can be continued, but when the carry signal is output (when step ST19 becomes Y), the carry signal is The output data in the counter area is reset (cleared) (step ST20), and the image forming unit 2 determines that its lifespan has expired and erases the code data in the corresponding memory _M1 (step ST21). moreover
The CPU 7 outputs a lifespan display signal to inform the operator of the lifespan of the image forming unit 2 (step ST22).

This lifespan display signal causes an unillustrated LED (light emitting diode) to light up, thereby informing the operator that the image forming unit 2 in use has reached its lifespan. In addition, when the image forming unit 2 is installed separately,
If there is no registration area in memory _M1 in RAM9 (step ST8 is N), a unit unusable signal is similarly output from CPU7 (step ST23).
It is possible to notify that the image forming unit cannot be used in the present image forming apparatus.

As described above, in this embodiment, each time the image forming unit is used, its code data is registered at the address "0" of the memory _M1 , and at this time, the previously registered code data is sequentially stored at the address "0". By always registering the recently used code data (image forming unit 2) at a small address value, when using the image forming unit 2, it is determined whether it was used immediately, and when the code data is used, for example. If the image forming unit to be used has just been used, or if the power has simply been turned off due to a paper jam, etc., the copying operation will be performed without first rotating the developer, etc. be.

[Effect of idea]

As explained in detail above, according to the present invention, the developing device etc. are pre-rotated only when using a new image forming unit or an image forming unit that has been left unused for a long period of time. Copying can be performed and image forming operations can be performed efficiently. That is, when the power is turned off due to a paper jam or the like, the pre-rotation process is not performed after the power is restored, and image forming operations can be performed quickly.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an electric circuit in this embodiment, FIG. 2 is a perspective view of an embodiment of the present invention, FIG. 3 is a perspective view showing a state in which the unit is installed in the main body of the image forming apparatus, and FIG. 4 is the configuration diagram of memories M ₁ and M ₂ ,
FIG. 5 is a flowchart. DESCRIPTION OF SYMBOLS 1... Image forming apparatus main body, 2... Image forming unit, 3... Photosensitive drum, 5... Driven gear, 5a
...Mark, 6...Photo sensor, 7...CPU,
8...ROM, 9...RAM, 10...S/P conversion circuit.

Claims (1)

[Scope of utility model registration request] In an image forming apparatus, an image forming unit including at least a developing unit is removably installed in an apparatus main body, and an initial operation of driving at least the developing unit is performed for a predetermined period of time when the apparatus is powered on. An image forming apparatus characterized in that the image forming apparatus has a determining means for determining whether replacement has been performed, and the predetermined time for performing the initial operation is varied depending on the determination result of the determining means.