JP2001154474A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device a toner shortage detection device capable of detecting shortage of toner in a toner container without arranging any special detecting means in the toner container for supplying toner to a developing device, and sensing a time to replace the toner container without misdetection. SOLUTION: This image forming device is provided with a means for calculating the integrated time of a toner sensor output signal and the integral of a toner feeding time, and a toner shortage state is displayed when the integral of the toner feeding time after the power source of the device is turned of exceeds the integrated time of the output signal showing that a toner sensor still detects remaining toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, a copying machine,
The present invention relates to an image forming apparatus having a toner supply device, which is applied to an image forming apparatus such as a facsimile.

[0002]

2. Description of the Related Art Conventionally, an apparatus for providing a hopper for storing toner upstream of a rotatable developing sleeve and detecting the remaining amount of toner in the hopper by a photoelectric unit provided in the hopper is disclosed in Japanese Unexamined Patent Application Publication No. 2002-163873. Showa 55-21027
Known as the official gazette. This device detects the amount of toner by increasing the amount of light reaching the light receiving element due to the light from the light emitting element being hindered by the toner between the light emitting element and the light receiving element of the photoelectric unit. When the number reaches the predetermined value, a first warning is displayed, counting of the number of copies is started, and when the number reaches a predetermined value, a second warning is displayed indicating that the apparatus cannot be used, and the main switch of the apparatus is automatically turned on. And the operation of the device is stopped.

If new toner is replenished in the hopper during the counting of the number of copies after the first warning is displayed, the first warning is turned off, the counting of the number of copies is stopped, and the counting circuit is reset. Things. However, since the toner replenishing method of this apparatus is not disclosed, the toner is replenished manually or visually, or the toner is replenished by mounting a toner container on the upper part of the hopper.

Therefore, when the toner is manually supplied, the periphery of the hopper may be contaminated with the toner powder and the recording surface of the recording medium may be contaminated. 2. Description of the Related Art There is known a toner container in which a toner supply port of a toner container is opened in synchronism with the mounting, and toner is supplied to a hopper.

[0005] However, if the toner supply amount is not controlled to an appropriate amount, the toner supply amount from the toner container to the hopper becomes excessive, and the toner is clogged at the aperture portion opened to the outlet side of the hopper due to the pressure and humidity of the toner. In some cases, supply to the toner developing sleeve may be hindered. Therefore, a stirring means is provided in the hopper,
Although the solidification of the toner is prevented, if the toner is supplied too much into the hopper, the load on the stirring means becomes excessive and hinders the stirring. Therefore, it is always desirable to supply an appropriate amount of toner in the hopper.

For this purpose, a toner sensor may be disposed at an appropriate position in the hopper, and the supply of toner from the toner container may be stopped by a signal when the toner in the hopper is accumulated until the toner is detected by the sensor. However, when a toner container is used, it is necessary to know the toner shortage state in the toner container and to replace the toner container.

[0007]

However, the toner shortage state in the toner container can be determined by the above-mentioned prior art or the method disclosed in Japanese Patent Application Laid-Open No. Hei 10-254231. When the amount of toner in the container is low, when the device itself is tilted, or when the amount of toner supplied from the toner container is not sufficient, it is erroneously detected that the toner is insufficient even though there is toner in the container. There was a problem that sometimes.

[0008]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention does not require any special detecting means in a toner container for supplying toner to a developing device, and detects toner shortage in the toner container to detect toner shortage. It is an object of the present invention to provide an image forming apparatus having a toner replenishing device capable of knowing a container replacement time. Another object of the present invention is to use a toner sensor that does not use an optical sensor, and thus does not affect the detection output even if the light transmission amount varies depending on the state of the toner in the developing device. An object of the present invention is to provide an image forming apparatus having a toner supply device for detecting.

Specifically, in the toner replenishing method for replenishing toner from a toner container into the developing device while detecting the amount of toner in the developing device for developing the electrostatic latent image on the surface of the photoreceptor, A toner sensor arranged in the container,
Toner supply means for supplying toner from the toner container to the developing device; operation time control means for controlling the operation time of the toner supply means to be longer than in the toner supply mode during normal printing; Control means for detecting the output signal and determining the toner supply time according to the state of the output signal; calculating means for calculating the integrated time of the output signal of the toner sensor and the integrated time of the toner supply time; and displaying the toner shortage state. Display means for displaying a toner shortage state when the integrated time of the toner supply time after the power of the apparatus is turned on exceeds the integrated time of the output signal of the toner sensor.

In the present invention, for example, as shown in FIG. 1, toner is supplied from the toner container 31 to the developing device 10. And the user installs the image recording device for the first time,
At the time of initial installation of the toner for supplying an appropriate amount of toner from the toner container 31 to the developing device 10 in order to prepare for printing, the toner is not in the developing device 10 at all. It is necessary to supply a larger amount of toner than the amount of toner to be supplied, so that a long toner supply time is required.

Further, when the amount of toner in the developing device 10 is detected to be less than a predetermined amount, toner is supplied from the toner container to the developing device 10 for a predetermined supply time. By stopping the supply,
During normal printing, the amount of toner in the developing device is controlled. In this case, the reason why the toner supply is performed for a predetermined time is to prevent an excessive toner supply due to erroneous detection. Further, for each printing, the integration of the time during which the predetermined amount of toner in the developing device 10 is satisfied and the integration of the toner replenishment time are compared after the power supply of the apparatus is turned on, and the predetermined amount of toner in the developing device 10 is satisfied. When the sum of the toner supply time exceeds the sum of the time, the display unit 47 displays a toner shortage state in the container.

Therefore, the toner can be replenished from the toner container 31 to the developing device 10 both during the initial installation and during the normal printing without providing a special toner detecting means in the toner container 31. Can be displayed.

[0013]

Embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention, but are merely illustrative examples. It's just

FIG. 1 shows an embodiment of an image forming apparatus to which the present invention is applied. The image forming apparatus 1 includes an a-Si photosensitive drum (photosensitive member) 9 which rotates clockwise in FIG. The developing device 10, the transfer roller 19,
A cleaning sliding roller 11, a cleaning blade 13, and a charging unit 8 for cleaning are provided.

The developing device 10 is provided with a developing roller 32, and the surface of the developing roller 32 is separated from the surface of the photosensitive member 9 by a predetermined distance. The developing device 10 is configured to be able to appropriately supply a predetermined amount of toner from the toner container 31. The upper door 7 is arranged above the toner container 31 so as to be openable and closable around the base 7a in the direction of the arrow, so that the toner container 31 is detachable.

An optical transmission mechanism 5 for forming image dots on the surface of the photoconductor 9 is provided above the photoconductor 9, and the optical transmission mechanism 5 includes a polygon mirror 2 for reflecting laser light from a laser light source (not shown), An optical system 3 for forming an image dot on the surface of the photoreceptor between the charging unit 8 and the developing roller 32 through the reflection mirror 4 with the laser light is provided.

A base 54 for accommodating a control circuit 71 for controlling the apparatus, which will be described later, is provided below the image forming apparatus 1, and a recording paper container 55 is removably disposed above the base 54 from outside. The pre-transfer recording paper storage 14 is provided in the recording paper container 55, and the recording paper placed on the pressing spring 52 faces the auxiliary roller 30 through the passages 16 and 17 by the conveying rollers 53 and 15. It is configured to be able to be conveyed to the provided registration roller 18.

On the right side of the image forming apparatus 1, a front door 50 is provided.
When the front door 50 is opened as indicated by 50 ', the front door 50' is arranged so as to be openable and closable as indicated by a virtual line 50 '.
The recording paper placed on the paper is transported to the passage 17 by the transport roller 51.

On the left side of the image forming apparatus 1, a fixing roller 2
The fixing unit is constituted by 3 and 24, and the recording paper passing between the photosensitive member 9 and the transfer roller 19 is fixed by the fixing rollers 23 and 24.
The recording paper after fixing is transported by the transport rollers 25, 2
6, the recording paper is accumulated on the transferred recording paper accumulation table 6 by rollers 28 and 29.

A display unit 47 for displaying various information, an installation switch 48, and a power switch 49 are provided on the upper part of the image recording apparatus 1.

The image recording apparatus 1 configured as above is
When the power switch 49 is closed, the main motor (not shown) starts driving, the photoconductor 9 is rotated clockwise by the start switch (not shown), and the optical transmission mechanism 5 forms an image on the surface of the photoconductor 9, Is developed by a developing roller 32 of the developing device 10, and the developed image is transferred to recording paper by a transfer roller 19, and is fixed to the fixing rollers 23 and 24.
, And are conveyed to the stacking table 6 by the rollers 25, 27, 28, and 29 to be stacked.

Next, each main part of the image forming apparatus 1 will be described. FIG. 2 is a sectional view showing the configuration of the developing device and the toner container, FIG. 3 is a perspective view showing the inside of the developing device, and FIG.
It is -A sectional drawing. In these figures, the developing device 10
Are storage chambers 10b and 10 in which magnetic one-component toner is stored.
c and a rotatable non-magnetic developing sleeve 32a
And a magnet 32 having a plurality of magnetic poles fixed therein.
b and a developing roller chamber 10e in which the developing roller 32 is disposed, and the surface of the developing roller is separated from the surface of the photoconductor 9 by a predetermined distance.

A wall 10a for separating the storage chambers 10b and 10c is planted along the longitudinal direction at the center of the developing unit 10, and a piezoelectric sensor 39 is provided at the center of one wall 10g.
However, the pressing surface 39a is disposed so as to protrude slightly inside the wall surface 10g. The piezoelectric sensor 39 applies a predetermined voltage at a predetermined cycle under the control of a control circuit 71 described later,
In the above cycle, the pressing surface 39a vibrates in a direction intersecting with the wall surface 10g, the vibration stops when the developer is filled with the toner, and the positive and negative voltages are input to the control circuit by the vibration of the piezoelectric sensor. It is configured such that a positive voltage is input to the control circuit by stopping the vibration.

At the center of the storage chambers 10b and 10c,
The first spiral shaft 41 and the second spiral shaft 42 are both provided so that the toner presses the spiral wrap toward the wall surface 10g. 10g, and is disposed between the opposite wall 10h and rotatably clockwise. These spiral shafts are gears 45 provided on the outer wall surface of the developing device 10, respectively.
It is connected to a main motor 65 (FIG. 6) via 46.

Stir bars 43, 44 are mounted on the spiral shaft bearings 41a, 41a and 42a, 42a, respectively, so as to rotate and pass through positions deviated from each other by 180 °. And the stirring trajectory of the stirring rods 43 and 44 is the wall 1
0a, the toner in the storage chamber 10b can be easily moved to the next storage chamber 10c by the stirring rod 43, and the toner can be easily moved to the next storage chamber 10c by the stirring rod 43. When the toner is being moved to the storage room 10c, the stirring rod 44 in the storage room 10c
Is located at a position deviated by 180 °, the two stirring rods do not push the toner, and there is no hindrance to the transfer of the toner from the storage chambers 10b to 10c.

Incidentally, the deviation angle of the two stirring rods is not limited to 180 °, but may be any angle as long as the transfer of the toner from the storage chambers 10b to 10c is not hindered. Further, a configuration without using the stirring cap 44 may be adopted.

A developing roller 32 is provided in a storage chamber 10e provided on the left-hand side of the storage chamber 10c. The developing roller 32 includes a developing sleeve 32a and a developing sleeve 32 which are rotatable to the outside in a direction indicated by an arrow. 32a, the N pole on the photoconductor 9 side,
A magnet having the N pole sandwiched between the S poles is fixedly disposed, and is separated from the surface of the developing sleeve 32a by a predetermined distance.
and an opening 10j for supplying toner to the developing sleeve side at an end of the side seal 10d.
On the left side of the S pole 56, a regulating blade 40 for regulating the toner layer is provided on the surface of the developing sleeve 32.

When the toner container 31 is mounted on the developing device 10, the developing sleeve 32a is connected to a main motor so as to be rotatable in the direction of the arrow. The photoreceptor 9 is arranged so that the surface of the photoreceptor 9 is located at a predetermined distance from the surface of the developing roller 32, and the toner agitated in the developing unit 10 and regulated by the developing sleeve 32a is applied to the developing roller 32. The magnetic poles are formed by the N poles in 32, and the image on the surface of the photoconductor 9 is developed.

An aperture 1 is provided on the upper surface of the developing device 10.
0f is opened, and when the toner container 31 is mounted on the developing device 10, the opening / closing door 38 having the toner discharge port 38a moves in conjunction with a mechanism (not shown) to move the aperture 10f.
, The toner discharge port 38a is opened.

An aperture 38 is provided in the toner container 31.
a, a supply roller 33 for supplying toner through the a.
The supply rollers 33 and the stirring blades 36 and 37 are connected to a toner supply motor 67 (FIG. 6) when the toner container 31 is mounted on the developing device 10. It is configured.

Next, the operation of the developing device 10 and the toner container 31 configured as described above will be described. FIG. 5 is an explanatory diagram for exchanging the toner container 31. In the figure,
The upper door 7 is opened and raised as shown in the figure, the toner container 31 is taken out of the image forming apparatus 1 from the state of the toner container 31 shown by the solid line to the state shown by the virtual line 31 ', and a new toner container is inserted. Can be used to replace the toner container.

As shown in FIG. 2, when the toner container 31 is mounted on the developing unit 10, the opening / closing door 38 is opened, the opening 38a and the aperture 10f of the developing unit 10 are aligned, and the toner is supplied by the rotation of the supply roller 33. Developing unit 10 storage room 10
It falls into b. The piezoelectric sensor 39 receives positive and negative signals of a predetermined period from the control circuit, and the pressing surface 39a vibrates. However, toner is accumulated between the side walls 10g and 10h shown in FIG. When the piezoelectric sensors 39 accumulate to the extent that they are pressed, the piezoelectric sensor 39 remains pressed to one side.

This signal indicates that a proper amount of toner has been accumulated in the developing device. On the other hand, the toner is agitated by the spiral shafts 41 and 42, charged, and sequentially sent to the storage chamber 10c. Then, the toner flies to the photoconductor 9 by the developing roller 32 to develop the surface of the photoconductor 9.

The total length L1 of the developing roller 32 is slightly shorter than the distance between the side walls 10g and 10h of the developing unit 10 in FIG. 4, but the regulating blade 40 is provided between both side walls. The scattering of toner between the end surface and the side wall surface is prevented as much as possible. Also, the wall 10a of the developing device 10
Is erected at the center, but the entire length L2 of the wall portion 10a is shorter than the entire length L1 of the developing roller 32 without the side wall of the developing device. The toner flow 57, 5 flowing by the spiral shaft 42
7 is formed.

The entire length L3 of the opening 38a provided on the toner storage chamber 10b side is shorter than the entire length L2 of the wall 10a as shown in FIG. 4, so that the toner dropped from the opening 38a is agitated. The storage room 10c directly by the rod 43
The toner is moved by the spiral shaft 41 in the direction of the arrow 58 and circulates outside the toner flow indicated by the arrow 58 near the spiral axis as the toner flows 59 and 57.

Further, in the storage room 10c, the toner flows as the toner flow 57, or a small amount of the toner flows over the wall 10a from above by the stirring rod 43, and the toner flows in the storage room 10c through the toner flow 58, 57, Alternatively, circulation is performed in the developing device as 58 and 59.

As described above, the inside of the developing device 10 is formed such that the total length L1 of the developing roller, the total length L2 of the wall 10a, and the total length L3 of the toner receiving port 38a satisfy the relationship of L1>L2> L3. In receiving the toner from the toner container 31, the toner is not scattered and supplied to the developing roller side due to insufficient charging due to insufficient stirring.

Next, a control circuit for controlling the toner supply device will be described. As shown in FIG. 6, the control circuit 71 is mounted in the base 54 of the image forming apparatus 1. Control circuit 7
1 includes a CPU (central processing element), a counting circuit, and the like inside, a power switch 49 for supplying power to the image forming apparatus 1 at an input end, and an installation indicating that a user supplies toner to the apparatus for the first time. The switch 48, a recording sheet counting means 62, and information such as the state of the piezoelectric sensor 39 can be input, and a ROM 63 storing a control program and a RAM 64 storing measurement values and a calculation unit are connected. .

The output terminals include a main motor 65 for supplying power to the image forming apparatus 1, an electromagnetic clutch 66 connected to the main motor 65 to rotate the photosensitive member 9, a toner supply motor 67 for the toner container 31, Operating time control means 6 for controlling the operating time of the toner supply motor 67
8, a motor speed control means 70 capable of variably controlling the rotation speed of the toner supply motor 67, a toner supply stop means 69 for stopping the motor even within the operation time of the toner supply motor depending on the toner supply state, The optical transmission mechanism 5 for transmitting image information to the surface to form an image, a display unit 47 for displaying various information, and a piezoelectric sensor (toner sensor) 39 composed of a piezoelectric sensor are connected.

Next, the operation of the toner replenishing apparatus will be described with reference to FIGS. FIG. 7 is a flowchart illustrating an installation mode in which a user installs the image forming apparatus and uses the image forming apparatus for the first time. 2, the upper door 7 of the image forming apparatus 1 is opened, the toner container 31 is mounted on the developing device 10, and the upper door 7 is closed. Press the power switch 49 (1
02), “Not Ready” is lit on the display unit 47 (103), the main motor 65 is driven (104), and the output signal from the piezoelectric sensor (toner sensor) 39 is checked.

When the installation switch 48 is pressed (10
5) The toner supply motor 67 of the toner container 31 is driven (106), the toner in the toner container 31 is loosened by the stirring blades 36 and 37, and the toner is dropped into the developing device 10 by the supply roller 33. .

The operation time of the toner supply motor 67 is longer than that during normal toner supply, and is set to a first predetermined value of 600 seconds (107). Within this predetermined value, the toner sensor
When the level is at the level (the pressing surface of the piezoelectric sensor is depressed by pressing with toner) (108), the toner supply motor is stopped (109), the toner stirring motor 70 is stirred for 60 seconds (110), and the developing is performed. The toner in the container is agitated by a spiral shaft, and “Not Read” on the display unit 47 is displayed.
The display of "y" is turned off (111), and normal printing is enabled.

In step 105, if an install signal is not received (105), the process proceeds to step C in the normal mode shown in FIG. The toner supply motor is driven (139)
Then, the rotation time of the toner supply motor is set to a second predetermined value 420 seconds, which is shorter than that in the installation mode, and it is determined whether the output value of the toner sensor is fixed at the H level within that time. In the installation mode, a time of the first predetermined value is required, and the H level signal is not output, the second predetermined value is passed (140), and the power is turned off (134).

At this point, when the toner container is inserted again (135) and the power is turned on (136), "Not"
"Ready" is displayed (137), the main motor is driven (138), and the toner sensor outputs the H level (141), and the end of replacement is displayed (142).

When the first predetermined value elapses (107) without the toner sensor being at the H level, "toner container replacement" is displayed (112), the power is turned off (113), and the toner container is replaced (114). Then, when the power is turned on (102), steps 103 to 110 are passed, the "Not Ready" display is turned off (111), and the toner supply is completed.

Next, the operation in the normal mode will be described. 8, the power switch of the image forming apparatus 1 is turned on (1
20) Then, “Not Ready” is displayed (12)
1), the main motor is driven, and the counting of the toner sensor H level (toner presence signal) time is started (1).
22) Then, it is determined whether or not the toner sensor is at the L level (that is, whether or not the toner sensor is at the H level) (12).
3) If it is at the L level, the toner supply motor is driven and the counting of the toner supply time is started (124).
The toner is supplied to the developing device for a predetermined supply time.

The integration of the toner supply time is compared with the integration of the toner sensor H level (125). If the integration of the toner supply time exceeds the integration of the toner sensor H level, "T
and the count of the toner supply time and the toner sensor H level is ended (12).
6) Then, after printing a predetermined number of sheets (for example, 50 sheets) (128), "Replace toner container" is displayed (12).
9) Then, go to step B.

In step 127, if the output of the toner sensor is at the H level for 3 seconds or more, it is determined that the replenishment amount is larger than the toner consumption amount, and "Ton"
The “erLow” display is turned off (133), and the process proceeds to step A.

When the "toner container replacement" display is turned on (129), the power is turned off (13) in FIG.
4), replace the toner container (135), and turn off the power.
N (136), “Not Ready” is displayed (1
37), the main motor is driven (138), the toner supply motor is driven (139), and the control circuit issues a rotation command for the toner supply motor for 420 seconds (second predetermined value). When the output signal of the toner sensor attains the H level (141), an exchange completion display (142) is performed.
The toner supply motor is stopped (143).

In step 140, if the diameter exceeds the second predetermined value, the flow returns to step B, and steps 134 to 1 are executed.
Repeat between 40.

In step 105, the toner supply motor 67 is controlled by the motor speed control means 70 by turning off the install switch 48 (FIG. 6).
It can also be rotated faster than during normal mode supply.
Thus, the toner supply amount in the installation mode can be larger than the toner supply amount in the toner supply mode, the toner supply time in the installation mode can be shortened, and the toner can be agitated in the developing device earlier. Therefore, non-uniformity of toner charge and fogging in the developing device due to a large amount of toner replenishment in the toner replenishing mode, and the scattering time of toner from the toner container into the developing device can be reduced, thereby preventing contamination of the image forming apparatus. it can.

As described above in detail, in the present embodiment, the toner supply operation time for supplying toner from the toner container to the developing device is set longer than the initial installation mode when there is no toner in the developing device. The replenishment mode is set shorter to supply toner by detecting less than a predetermined amount of toner in the developing device, and by detecting a predetermined amount of toner to stop and control the supply of the toner, to thereby reduce the amount of toner in the developing device. When the consumption amount is larger than the supply amount under the conditions, or when the toner supply operation time elapses in the initial installation mode, the toner container replacement is displayed, so that a special toner detecting unit is provided in the toner container. Even if it is not provided, the toner can be supplied from the toner container to the developing device at the time of initial installation and during normal printing, and It is possible to display the time to replace the toner container.

Conventionally, only the sensor signal is used to make a determination, so that when there is no toner near the sensor for some reason, an erroneous detection is made. Since the toner shortage state is detected by comparing the values, the determination can be made relatively accurately based on the quantitative relationship between the toner consumption amount and the toner supply amount.

[0054]

As described above, according to the present invention, no special detecting means is provided in the toner container for supplying the toner to the developing device, and the shortage of the toner in the toner container is determined by the integrated time of the toner supply time. By comparing the integrated time of the output signal of the toner sensor with the integration time, it is possible to provide an image forming apparatus having a toner replenishing device that reliably and accurately detects a toner shortage state.

[Brief description of the drawings]

FIG. 1 is an embodiment of an image forming apparatus to which the present invention is applied.

FIG. 2 is a cross-sectional view illustrating a configuration of a developing device and a toner container.

FIG. 3 is a perspective view showing the inside of the developing device.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

FIG. 5 is an explanatory diagram for replacing a toner container.

FIG. 6 is a block diagram of a control circuit.

FIG. 7 is a flowchart in an installation mode.

FIG. 8 is a flowchart of a first half in a normal mode.

FIG. 9 is a flowchart of the latter half of the normal mode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Polygon mirror 5 Optical transmission mechanism 7 Upper door 9 Photoconductor 10 Developing unit 11 Rubbing roller 31 Toner container 32 Developing roller 33 Supply roller 39 Toner sensor 47 Display part

Claims (2)

[Claims] An image forming apparatus having a toner supply device for supplying toner from a toner container to a developing device for developing an electrostatic latent image on a photoreceptor surface, a toner sensor disposed in the developing device; Toner supply means for supplying toner from the toner container to the developing device, operation time control means for controlling the operation time of the toner supply means to be longer than in the toner supply mode during normal printing, and an output signal of the toner sensor Control means for detecting the toner supply time according to the state of the output signal; calculating means for calculating the integrated time of the output signal indicating the presence of toner from the toner sensor and the integrated time of the toner supply time; Display means for displaying, when the integrated time of the toner supply time after turning on the power of the apparatus exceeds the integrated time of the output signal of the toner sensor. An image forming apparatus having a toner replenishing device for displaying a toner shortage state. 2. The image forming apparatus according to claim 1, wherein said toner sensor is a piezoelectric sensor.