JP3495190B2 - 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 such as a copying machine, a facsimile and a printer.

[0002]

2. Description of the Related Art Generally, an image forming apparatus includes an image carrier such as a photosensitive drum which is rotationally driven by a main motor,
A latent image forming means for writing an image on the image carrier by an image signal to form an electrostatic latent image, and a two-component developer composed of toner and carrier by the developing unit for developing the electrostatic latent image on the image carrier. A developing device that develops a toner image to replace the toner container by replenishing the developing unit with toner from a toner container such as a toner bottle and the toner container is in a toner end or toner near end state; The toner concentration of the developer is detected by the toner concentration sensor, and toner is replenished from the toner container to the developing unit so that the toner concentration of the developer in the developing unit becomes a predetermined toner concentration based on the detected value. A toner density control means for controlling the image density, and after the toner container is replaced, the image type is formed for a predetermined time in order to replenish the toner from the toner container to the developing section. It prohibits the operation.

In recent years, the developing device is often used in which a plurality of screw-shaped developer stirring / conveying members and a developer carrying member are horizontally arranged. This is because the developing device has a simple structure, can be manufactured at low cost, and can be downsized, but the toner replenishing means in this developing device has a screw shape in order to take advantage of the downsizing of the unit. There is often used a configuration in which the toner is replenished from the end portion on the developer stirring and conveying member side.

24 to 26 show a developing section of an example of the developing device. The stirring screws 1 and 2 as the developer stirring / conveying member and the developing sleeve 3 as the developer carrying member are rotationally driven by a driving source (not shown). The two-component developer consisting of the toner and the carrier in the developing container 4 is stirred by the stirring screw 1, conveyed from the front side of the apparatus to the rear side of the apparatus, folded at the end of the rear side of the apparatus, and then stirred by the stirring screw 2. At the same time, it is conveyed from the back side of the device to the front side of the device.

The developer conveyed by the stirring screw 2 is transferred to the developing sleeve 3 during the conveyance, and the developing sleeve 3 magnetically attracts and holds the developer by an internal magnet and conveys it along with the rotation. To do. The developer on the developing sleeve 3 is regulated to a predetermined amount by a doctor blade 5 as a regulating member, and when passing through the developing area between the developing sleeve 3 and the image carrier 6, the developer on the image bearing body 6 is kept static. After the electrostatic latent image is developed into a toner image, it is returned to the stirring screw 2.

Stirring screws 1, 2 and developing sleeve 3
Is arranged horizontally, and a toner supply port 7 is provided at the end on the side of the stirring screw 1. The toner replenishing unit (not shown) is configured by using a toner bottle as a detachable toner container, and replenishes the toner contained in the toner bottle to the developing unit from the toner replenishing port 7. The developer replenished from the toner replenishing port 7 is mixed with the developer in the developing section in the vicinity of the turnaround on the front side of the apparatus, and the developer is stirred.
The toner density gradually becomes uniform by stirring and transporting with.

The toner density of the developer in the developing section is detected by a toner density sensor 8 as a toner density detecting means, and an image forming apparatus control circuit (not shown) causes the toner replenishing section to develop the toner based on the output value of the toner density sensor 8. The toner concentration of is controlled to a predetermined toner concentration. The developer consumes toner by developing the electrostatic latent image on the image carrier 6 and is replenished with toner from the toner bottle, and the toner bottle is in a toner end state or a toner near end state (no toner or a state close thereto). Is detected by the toner end (or toner near end detection means).

The image forming apparatus control circuit controls each part of the image forming apparatus when the toner bottle is in the toner end (or toner near end) state by the detection signal from the toner end (or toner near end detection means). When the forming operation is stopped and the display shows that the toner bottle is in the toner end (or toner near end) state, the operator opens the front door to see the display and the toner is stored in the toner bottle. Close the front door after replacing with a new toner bottle.
The image forming apparatus control circuit considers that the toner bottle has been replaced when the front door is opened for a predetermined time by the input signal from the front door switch that detects the opening and closing of the front door, and releases the inhibition of the image forming operation. To enable the image forming operation.

[0009]

FIG. 27 shows the results of measurement of the relationship between the amount of toner replenished from the toner container to the developing portion and the amount of charge of toner in the developer in the developing device. In this measurement, the charge amount of the toner was applied to the developer in the central portion of the developing sleeve 3. The linear velocity of the image carrier 6 is 90 mm /
sec, the developing sleeve 3 is φ20, and the linear velocity is 200.
mm / sec. The stirring screws 1 and 2 are φ25 and the linear velocity is 225 mm / sec. The developer is adjusted to have a toner concentration of 5.0 wt% and a toner charge amount of 20.0 μC / g. The amount of developer is 400g,
The developer makes one round in the developing section in about 60 seconds.

Since the toner concentration is lower than the reference value when the toner is replenished, FIG. 27 shows each developer whose toner concentration is 3.0 wt%, 3.5 wt%, 4.0 wt%. 5 shows the relationship between the toner charge amount of the developer in the central portion of the developing sleeve 3 and the toner replenishment amount 45 seconds after the toner is replenished. FIG. 27
Therefore, when the toner charge amount becomes 16.0 μC / g or less, that is, when the toner is replenished at 0.15 g / sec or more,
It can be seen that the background stain occurs.

As described above, when the developing device has a large amount of toner replenishment per unit time, background stains (particularly, edge stains) occur. Therefore, in the image forming apparatus,
When the toner bottle is in the toner end or toner near end state, the image forming operation is prohibited thereafter for a predetermined time.Therefore, when the toner replenishment amount per unit time in the developing device is large, the image forming operation is performed after the toner bottle is replaced. Prohibition time becomes longer. Therefore, the waiting time after replacement of the toner bottle becomes long, which is inconvenient when it is desired to form an image immediately.

According to the present invention, it is possible to improve the productivity of the image-formed product by eliminating the waiting time after the toner container is replaced, and the image forming operation can be performed without replacing the toner container in the toner end or toner near end state. If you do, you can solve the problem caused by the decrease in toner concentration,
The image density quality after replacing the toner container can be improved,
It is possible to prevent background stains by suppressing changes in image density due to temperature changes and humidity changes, and obtain stable image density quality without deterioration of image density over time. An object of the present invention is to provide an image forming apparatus capable of selecting the productivity of the image forming apparatus.

[0013]

In order to achieve the above object, the invention according to claim 1 provides an image carrier and a latent image forming an electrostatic latent image by writing an image on the image carrier by an image signal. The image forming means and the electrostatic latent image on the image carrier are developed with a developer by a developing unit to form a toner image, and toner is replenished from the toner container to the developing unit and the toner container is in a toner end or toner near end state. When the toner container is replaced, the number of dots of the image to be developed next is measured in the image forming apparatus that prohibits the image forming operation when the toner container is replaced. Means for measuring the number of developed image dots, and the image of the image to be developed next in the developing unit based on the measured value of the means for measuring the number of developed image dots during the image forming operation inhibition time after the toner container is replaced. Quantity G is an operation enabling means for enabling the image forming operation when it is below a predetermined value, this
Means for activating the toner container from the toner container to the developing unit.
Toner supply should be done at least once after replacing the toner container.
Enable image forming operation after confirming that it has been done
Therefore, minimize the waiting time after replacing the toner container and
Productivity can be increased and toner end
Or replace the toner container in the toner near end state.
Lower toner density when image forming operation is performed without
It is possible to solve the problem caused by.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the toner after the toner container is replaced
Depending on the toner replenishment time from the toner container to the developing unit,
The toner is provided with means for changing a predetermined value.
Shorten the waiting time after container replacement and ensure sufficient toner concentration.
It is possible to obtain the image density.

According to a third aspect of the invention, in the image forming apparatus according to the first aspect, the toner of the developer in the developing section is used.
Toner concentration detecting means for detecting the concentration and this toner concentration
Means for varying the predetermined value according to the output value of the detection means
And the wait time after replacing the toner container.
It is possible to shorten and obtain sufficient toner density and image density.
It becomes Noh.

According to a fourth aspect of the invention, in the image forming apparatus according to the first aspect, a reading device for reading an original image is provided.
Installed in the reading device and then in the developing unit.
Development image dot number measurement to measure the number of dots of the imaged image
Fixing means and the image forming operation after the toner container is replaced.
Measured value of the developed image dot number measuring means during the work prohibition time
The number of dots of the image developed in the developing section next based on
The operation that enables the image forming operation when the value is less than a predetermined value.
Are those having a work enabling means, after the toner container replacement
To minimize the waiting time for
And are possible.

According to a fifth aspect of the invention, in the image forming apparatus according to the first aspect, the image signal is developed.
Memory and the number of dots of the image to be developed next in the developing section
To measure the developed image dot number using the memory
And the image forming operation is prohibited after the toner container is replaced.
Based on the measured value of the developed image dot number measuring means during the stop time
Next, the number of dots of the image developed in the developing unit is predetermined.
When the value is less than or equal to
It is equipped with an activation means, and waits after replacing the toner container.
It is possible to increase the productivity of image-formed products by minimizing the time.
It will be possible.

According to a sixth aspect of the invention, in the image forming apparatus according to the first aspect, the temperature inside the image forming apparatus is detected.
By knowing the temperature, the measured number of dots of the developed image can be measured.
It is those having a correction means for correcting a value, toner containers
Minimize the waiting time after changing the equipment to improve the productivity of image-formed products.
It is possible to increase the image density and
It is possible to prevent soiling and prevent soiling of the background.

According to a seventh aspect of the invention, in the image forming apparatus according to the first aspect, the humidity inside the image forming apparatus is detected.
Knowing the humidity, the measured number of dots of the developed image can be measured.
It is those having a correction means for correcting a value, toner containers
Minimize the waiting time after changing the equipment to improve the productivity of image-formed products.
It is possible to increase the
It is possible to prevent soiling and prevent soiling of the background.

According to an eighth aspect of the present invention, in the image forming apparatus according to the first aspect, the process from the developer replacement in the developing unit is performed.
The number of image formations is measured, and the development is performed according to the number of image formations.
Equipped with correction means to correct the measurement value of the image dot number measurement means
And minimize the waiting time after replacing the toner container.
It is possible to increase the productivity of image-formed products by
Stable image density quality that does not decrease with time
Obtainable.

According to a ninth aspect of the invention, in the image forming apparatus according to the first aspect, a main unit that rotates the image carrier is used.
Motor and the developer of the main motor
The driving time from the
Equipped with correction means for correcting the measurement value of the image dot number measurement means
And minimize the waiting time after replacing the toner container.
It is possible to increase the productivity of image-formed products by
Stable image density quality that does not decrease with time
Obtainable.

According to a tenth aspect of the invention, in the image forming apparatus according to the first aspect, the reading for reading the original image is performed.
Measuring the drive time of the device and this reading device
The measured value of the developed image dot number measuring means is supplemented by time.
It is equipped with corrective means to correct and replaces the toner container.
Increase the productivity of image formation by minimizing the waiting time afterwards
This makes it possible to reduce the image density with the passage of time.
It is possible to obtain a fixed image density quality.

According to an eleventh aspect of the present invention, in the image forming apparatus according to the first aspect, the operation enabling unit is operated.
Selects whether to are those having a selection means, image
Image density quality and productivity of imaged product can be selected.
Wear.

[0024]

[0025]

[0026]

FIG. 1 shows an embodiment of the invention according to claim 1. In this embodiment, a plurality of screw-shaped developer stirring / conveying members and a developer carrier are arranged in a horizontal direction to supply toner from an end portion on the screw-shaped developer stirring / conveying member side. 1 is an embodiment of a digital image forming apparatus including a digital copying machine using the apparatus 11.

An image carrier made of a photoconductor, for example, the photoconductor drum 12, is rotationally driven in the sub-scanning direction by a drive source made of a main motor (not shown), uniformly charged by a charger 13, and made up of a scanning optical system. An image is written by the writing means 14 to form an electrostatic latent image. In the scanning optical system 14, a light source 14a composed of a semiconductor laser is driven by a laser driver 15 by an image signal to emit light, and a light beam whose intensity is modulated by the image signal from the semiconductor laser is a deflecting means composed of a rotating polygon mirror. It is deflected by 14b.

A reading device (not shown) reads a document image to obtain an image signal, converts the image signal into a digital image signal, and outputs the digital image signal to the image processing section. The image processing unit performs a predetermined process on the digital image signal from the reading device to convert it into a digital recording image signal and outputs it. In the copy mode, the writing control unit 21 controls the laser driver 15 based on a control signal from the image forming apparatus control circuit 16 as a control unit to drive the semiconductor laser 14a by the image signal from the image processing unit.

In the printer mode, the image forming apparatus control circuit 16 expands the image signal input from the outside into the image memory, and the writing control unit 21 uses the laser driver based on the control signal from the image forming apparatus control circuit 16. The semiconductor laser 14a is driven by the image signal developed in the image memory by controlling 15. Further, the present embodiment has a facsimile function of transmitting / receiving an image signal to / from a destination through a public line and expanding the received image signal in the image memory, and the writing control section 21 is operated from the image forming apparatus control circuit 16 in the facsimile mode. The laser driver 15 is controlled based on the control signal to drive the semiconductor laser 14a by the received image signal developed in the image memory.

The light beam from the rotary polygon mirror 14b is focused on the photosensitive drum 12 via the fθ lens 14c and the folding mirror 14d to write an image, thereby forming an electrostatic latent image, and the rotary polygon mirror 14b The light beam is scanned in the main scanning direction on the photosensitive drum 12 by being rotationally driven by a driving source (not shown). The electrostatic latent image on the photosensitive drum 12 is developed by the developing device 11 and becomes a toner image. As the developing device 11, the developing device shown in FIGS. 24 to 26 described above is used.

The toner replenishing section of the developing device 11 is driven by the toner replenishing signal Sta from the image forming apparatus control circuit 16 to replenish the toner in the toner bottle 17 as a toner container to the developing section from its toner replenishing port 7. The toner end detection unit (or toner near end detection unit) detects that the toner bottle is in the toner end state (no toner is present) (or is in the toner near end state (a state in which there is almost no toner)).

The transfer material 18 made of transfer paper fed from the paper feeding device is transferred from the photosensitive drum 12 by transferring the toner image on the photosensitive drum 12 by a transfer separator 19 as a transfer means and a separating means. The toner image is separated, the toner image is fixed by a fixing device (not shown), and is discharged to the outside as an image-formed product. On the other hand, the toner remaining on the photosensitive drum 12 without being transferred onto the transfer paper 18 by the transfer separator 19 is
The toner is cleaned and collected by the cleaning device 20, stored in a waste toner collecting container (not shown), or sent to the developing section or the toner replenishing section of the developing device 11 for toner recycling. After that, the photoconductor drum 12 is uniformly charged by the charger 13 in preparation for another optical writing. Such an image forming operation is started when the copy button of the operation unit is pressed and turned on, and is continuously repeated for the number of sheets set by the operation unit.

Further, the output signal Vt of the toner density sensor 8
c is sent to the image forming apparatus control circuit 16, and the image forming apparatus control circuit 16 adjusts the toner concentration of the developer in the developing unit to a predetermined toner concentration based on the output signal Vtc of the toner concentration sensor 8. Toner supply signal Sta
Is output to control the toner replenishment from the toner bottle 17 to the developing unit.

The writing pixel number detecting means 22 counts the image signals for the writing controller 21 to give to the laser driver 15 to drive the semiconductor laser 14a, so that the scanning optical system 14 is moved to the photosensitive drum next. The number of dots of the image to be written in 12 is measured before writing the image.

As shown in FIG. 2, the image forming apparatus control circuit 16 executes a step when the toner bottle is in the toner end (or toner near end) state by the detection signal from the toner end detection means (or toner near end detection means). In S1, each part of the image forming apparatus is controlled to stop the image forming (image forming) operation to prohibit the image forming operation, and at the same time, the toner bottle is in the toner end (or toner near end) state on the display. A message and "please wait for a while" are displayed, and the operator opens the front door by looking at the display and replaces the toner bottle with a new toner bottle containing toner, and then closes the front door. Opening and closing of the front door is detected by the front door switch.

The image forming apparatus control circuit 16 has a toner bottle replacement detection function for detecting the replacement of the toner bottle 17, and whether the front door is opened for a predetermined time Tr in step S2 by an input signal from the front door switch, for example. If it is determined that the toner bottle has been replaced when the front door is opened for a certain period of time Tr, it is considered that the toner bottle has been replaced, and in step S3, the image display (copyable) is displayed on the display unit. Next, the image forming apparatus control circuit 16 detects the output value S of the toner density sensor 8 in step S4, compares S with the output value S ₀ of the toner density sensor 8 with respect to the reference toner density in step S5, and S ≧ S. It is determined whether it is ₀ or not.

Here, the output value S of the toner density sensor 8 increases as the toner density increases. If S ≧ S ₀ , the image forming apparatus control circuit 16 considers that the toner recovery (toner end or toner near end recovery) is completed in step S6, and controls each unit of the image forming apparatus to interrupt the operation. Resume the image movement.

Further, the image forming apparatus control circuit 16 sets S ≧
If it is not S _0, the input signal from the copy button is checked in step S7, and if the copy button is turned on, the input signal from the writing pixel number detection means 22 is fetched in step S8 and the image to be written by the next scanning optical system 14 is read. The number of dots (the number of pixels) D is detected, and in step S9 D is compared with a predetermined value D ₀ to determine whether D ≦ D ₀ .

If D ≦ D ₀ , the image forming apparatus control circuit 16 determines that normal image recording is impossible in step S10 and prohibits the image forming operation, and in step S11, “please wait for a while”. Is displayed and the process returns to step S3. Further, the image forming apparatus control circuit 16 controls D ≦
If D ₀ , it is considered that normal image recording is possible, and in step S12, each part of the image forming apparatus is controlled to restart the interrupted image forming operation, and in step S13, when the image forming operation ends, step S3 Return to.

As described above, in one embodiment of the invention according to claim 1, the photosensitive drum 12 as an image carrier, and an image is written on the image carrier 12 by an image signal to form an electrostatic latent image. The latent image forming means including the charging device 13 and the writing means 14, and the electrostatic latent image on the image carrier 12 is developed with a developer in the developing section to form a toner image, and the toner is supplied from the toner container 17 to the developing section. An image forming apparatus having a developing device 11 for replacing the toner container 17 when the toner container 17 is replenished and is in a toner end state or a toner near end state, and the image forming operation is prohibited when the toner container 17 is replaced. In the next step, the toner container 17 is replaced with the writing pixel number detecting means 22 as the developed image dot number measuring means for measuring the number of dots of the image developed next in the developing section. Number of dot images is a predetermined value D which is developed with measured values based then the developing unit of the image forming operation inhibition time in the developed image dot number measuring means 22 in
_Since the image forming apparatus control circuit 16 as an operation enabling unit that enables the image forming operation when the _value is ₀ or less is provided, the waiting time after the toner container replacement is minimized and the productivity of the image formed product is increased. It is possible, and it is convenient when it is desired to form an image immediately.

In one embodiment of the invention according to claim 1, since it is considered that the toner bottle has been exchanged and image formation is possible only by opening and closing the front door and turning on / off the power switch, toner end (or toner near end) In some cases, the image forming operation may be performed when the toner bottle is not exchanged, and the toner density may decrease and the developer may be damaged, or the carrier may adhere to the photosensitive drum 12. Occur.

Therefore, in an embodiment of the invention according to claim 2, in the embodiment of the invention according to claim 1,
In order to eliminate such a problem, the image forming apparatus control circuit 16 proceeds from step S2 to step S14 as shown in FIG. 3 to check whether or not the developing device 11 has replenished the toner after replacing the toner bottle. If the toner is replenished even once after the toner bottle is replaced, step S3
Proceed to. The image forming apparatus control circuit 16 executes step S14.
If the toner is not replenished once even after the toner bottle is replaced, it is repeatedly checked whether the toner is replenished after the toner bottle is replaced. If not, the message "please replenish toner" may be displayed on the display unit and the process may return to step S1.

In this embodiment, since image formation is possible if D ≦ D ₀ after toner supply is started after the toner bottle has been exchanged in the developing device 11, the toner bottle will remain in the toner end (or toner near end) state. When not replaced, the image forming operation is performed after the replenishment of the toner remaining in the toner bottle is started, the toner density is lowered and the developer is damaged, or the carrier adheres to the photosensitive drum 12. It is possible to solve problems such as rustling.

As described above, according to the second aspect of the present invention, in the image forming apparatus according to the first aspect, the image forming apparatus control circuit 16 as the enabling unit has the toner bottle as the toner container. Since it is possible to perform the image forming operation after confirming that the toner replenishment from 17 to the developing unit has been performed at least once after the toner container replacement, the waiting time after the toner container replacement can be minimized. It is possible to improve productivity, and it is possible to eliminate a problem due to a decrease in toner density when an image forming operation is performed without replacing the toner container in the toner end or toner near end state.

According to an embodiment of the invention of claim 3, in the embodiment of the invention of claim 1, the image forming operation is performed without replacing the toner container in the toner end or toner near end state. In order to solve the problem caused by the decrease in the toner density in the case of the above, the image forming apparatus control circuit 16 proceeds from step S2 to step S15 as shown in FIG. 4, and if the output value S of the toner density sensor 8 satisfies the predetermined condition, For example, the output value S of the toner density sensor 8 is detected, and if the output value S of the toner density sensor 8 is larger than the output value S ₀ ′ at a predetermined copyable reference toner density, it is determined that copying is possible and step S3. Proceed to.

Note that the image forming apparatus control circuit 16 does not exceed S ≧ S even if toner is replenished a predetermined number of times or more than a predetermined time after the toner bottle is replaced, as in the case of the embodiment of the invention according to claim 2. _{If the value} does not become ₀ ', the message "please replenish toner" may be displayed on the display unit and the process may return to step S5.

Therefore, in this embodiment, after S> S ₀ 'in the developing device 11 (that is, after the output value S of the toner density sensor 8 becomes larger than the output value S ₀ ' at the reference toner density). ) If D ≦ D ₀ , image formation is possible. Therefore, when the toner bottle is not replaced at the toner end (or the toner near end state), the copy operation cannot be performed, so that the toner concentration is lowered, It is possible to solve the problem that the developer is damaged by the image forming operation and the carrier adheres to the photosensitive drum 12.

As described above, according to the third aspect of the invention, in the image forming apparatus according to the first aspect, the image forming apparatus control circuit 16 as the operation enabling means functions as the toner density detecting means. Since the image forming operation is enabled when the output value of the toner density sensor 8 satisfies a predetermined condition, it is possible to minimize the waiting time after the toner container replacement and increase the productivity of the image formed product. When the image forming operation is performed without replacing the toner container in the end state or the toner near end state, it is possible to solve the problem caused by the decrease in the toner concentration.

In the above-described embodiment, the toner concentration of the developer changes momentarily according to the toner replenishment time during toner recovery (toner end or toner near end recovery), and the consumable toner amount changes. Since it varies depending on the toner density level (output value of the toner density sensor 8), the area ratio (dot number) of the image that can be output changes according to the toner replenishment time during toner recovery. However, after the toner recovery is completed, even if the amount of consumable toner changes every moment according to the toner replenishment time, if the number of dots D of the image developed next in the developing unit is D ₀ or less, Since it enables the forming operation,
In some cases, although image recording is possible, image recording is not performed, and the productivity of the image formed product cannot be sufficiently increased.

Therefore, in an embodiment of the invention according to claim 4, in the embodiment of the invention according to claim 1,
In order to sufficiently increase the productivity of the image-formed product, the image-forming-apparatus control circuit 16 proceeds from step S8 to step S16 as shown in FIG. 5, detects the toner replenishment time T of the developing device 11, and starts from step S17. In S19, T is T ₁ , T ₂ ,
Compared with T ₃ (T ₁ <T ₂ <T ₃ <Tr), T ≧ T ₁ , T ≧
It is determined whether or not T ₂ and T ≧ T ₃ .

If T <T ₁ , the image forming apparatus control circuit 16 compares the dot number (pixel number) D of the next written image with a predetermined value D _{1 in} step S20 to determine whether D ≧ D ₁ holds. If D ≧ D ₁ , the process proceeds to step S10. If not D ≧ D ₁ , the process proceeds to step S12. If T ₂ > T ≧ T ₁ , the image forming apparatus control circuit 16 compares the dot number (pixel number) D of the next written image with a predetermined value D _{2 in} step S21, and D ≧ D ₂ . Whether or not, D
If ≧ D ₂ , the process proceeds to step S10, and if D ≧ D ₂ , the process proceeds to step S12.

Further, the image forming apparatus control circuit 16 controls the T ₃
> T ≧ T ₂ If the number D (pixel number) D of the next write image is compared with a predetermined value D _{3 in} step S22, D ≧ D ₃
If D ≧ D ₃ , then step S1
The process proceeds to 0 and if D ≧ D _{3 is} not satisfied, the process proceeds to step S12.
Here, D ₁ , D ₂ and D ₃ are predetermined values determined by the number of dots of the image that can be output at the toner replenishment times T ₁ , T ₂ and T ₃ after the toner recovery is completed, and D ₁ <D ₂ <D ₃
Is. Further, the image forming apparatus control circuit 16 causes the step S
It progresses from 11 to step S16.

As described above, an embodiment of the invention according to claim 4 is the image forming apparatus according to claim 1, wherein the toner replenishment time from the toner container 17 to the developing portion after the toner container 17 is replaced is changed. The predetermined value D _{0 is set} to D ₁ , D
_Since the image forming apparatus control circuit 16 is provided as a means for changing to either ₂ or D ₃ , it is possible to shorten the waiting time after the toner container replacement and obtain sufficient toner density and image density.

An embodiment of the invention according to claim 5 is an improvement of the embodiment according to claim 3 as in the case of the embodiment according to claim 4. While one embodiment of the invention according to claim 4 changes the number of dots D according to the toner replenishment time T, one embodiment of the invention according to claim 5 is based on the output value S of the toner density sensor 8. The feature is that the number of dots D is changed, and the appropriate number of dots to be written is determined without being affected by the toner density before the start of toner recovery. From this point of view, the embodiment of the invention according to claim 5 has an improved control system as compared with the embodiment of the invention according to claim 4 described above.

In an embodiment of the invention according to claim 5, in the embodiment of the invention according to claim 1, in order to sufficiently increase the productivity of the image formed article, the image forming apparatus control circuit 16 is proceeds from step S8 as shown in 6 in step S23 detects the output value S of the toner density sensor 8, a predetermined value S in step S24 to S26 S _1, S _2,
Compared with S ₃ (S ₁ <S ₂ <S ₃ ), S ≧ S ₁ , S ≧ S ₂ , S
It is determined whether ≧ S ₃ or not.

If S <S ₁ , the image forming apparatus control circuit 16 compares the dot number (pixel number) D of the next written image with a predetermined value D _{1 in} step S 27 and determines whether D ≧ D ₁ is satisfied. If D ≧ D ₁ , the process proceeds to step S10. If not D ≧ D ₁ , the process proceeds to step S12. If S ₁ ≦ S <S ₂ , the image forming apparatus control circuit 16 compares the dot number (pixel number) D of the next written image with a predetermined value D _{2 in} step S 28, and D ≧ D ₂ . Whether or not, D
If ≧ D ₂ , the process proceeds to step S10, and if D ≧ D ₂ , the process proceeds to step S12.

Further, the image forming apparatus control circuit 16 causes the S ₃
> S ≧ S ₂ If the number D (pixel number) D of the next write image is compared with a predetermined value D _{3 in} step S29, D ≧ D ₃
If D ≧ D ₃ , then step S1
The process proceeds to 0 and if D ≧ D _{3 is} not satisfied, the process proceeds to step S12.
Here, D ₁ , D ₂ , and D ₃ are predetermined values determined by the number of dots of the image that can be output when the output values of the toner density sensor 8 are S ₁ , S ₂ , and S ₃ , and D ₁ <D ₂ <D ₃ . Further, the image forming apparatus control circuit 16 causes the step S11.
To step S23.

As described above, in one embodiment of the invention according to claim 5, in the image forming apparatus according to claim 1, a toner concentration sensor as a toner concentration detecting means for detecting the toner concentration of the developer in the developing section. 8 and the output value of the toner density detecting means 8, the predetermined value D _{0 is changed} to D ₁ , D ₂ ,
Since the image forming apparatus control circuit 16 is provided as a means for changing the value to any of D ₃ , it is possible to shorten the waiting time after the toner container replacement and obtain sufficient toner density and image density.

FIG. 7 shows an embodiment of the invention according to claim 6. In this embodiment, in the embodiment of the invention according to claim 1, the reading device 23 counts the number of pixels of the read image to determine the number of dots of the image to be developed next in the developing unit. It has a writing pixel number counting means 24 as a developed image dot number measuring means for measuring before development, and this writing pixel number counting means 24 is used instead of the writing pixel number detecting means 22.

The reading device 23 reads the original image in the copy mode, obtains an image signal and converts it into a digital image signal, and the writing pixel number counting means 24 in the copy mode reads the read image based on the digital image signal. By counting the number of pixels, the number of dots of the image developed next in the developing unit is measured, and the measured value is output to the image forming apparatus control circuit 16.

As described above, an embodiment of the invention according to claim 6 is, in the image forming apparatus according to claim 1, a reading device 23 for reading an original image, and this reading device 2.
3, the writing pixel number counting means 24 as a developed image dot number measuring means for measuring the number of dots of the image to be developed next in the developing section, and the image forming operation inhibition time after the toner container 17 is replaced. As an enabling means for enabling an image forming operation when the number of dots of the image to be developed next in the developing section is less than a predetermined value D ₀ based on the measurement value of the developed image dot number measuring means 24. Since the image forming apparatus control circuit 16 is provided, it is possible to minimize the waiting time after the toner container replacement and improve the productivity of the image formed product.

FIG. 8 shows an embodiment of the invention according to claim 7. In this embodiment, in the embodiment of the invention according to claim 1, in the facsimile mode or the printer mode, the number of pixels is counted based on the image signal (FAX signal or printer signal) developed in the image memory. Further, it has a writing pixel number counting means 25 as a developed image dot number measuring means for measuring the number of dots of an image to be developed next in the developing section before the development of the image, and the writing pixel number counting means 25 writes the above. It is used instead of the pixel number detection means 22. The writing pixel number counting means 25 counts the number of pixels based on the image signal developed in the image memory in the facsimile mode or the printer mode, so that the number of dots of the image to be developed next in the developing unit can be calculated. Measured before development,
The measured value is output to the image forming apparatus control circuit 16.

As described above, an embodiment of the invention according to claim 7 is, in the image forming apparatus according to claim 1, an image memory as a memory for expanding the image signal, and then the developing section. Writing pixel number counting means 25 as a developed image dot number measuring means for measuring the number of dots of the image developed by using the memory, and the developed image during the image forming operation inhibition time after the toner container 17 is replaced. An image forming apparatus as an operation enabling unit that enables an image forming operation when the number of dots of an image developed in the developing unit based on the measurement value of the dot number measuring unit 25 is equal to or less than a predetermined value D _0. With the control circuit 16,
It is possible to improve the productivity of the image formed product by minimizing the waiting time after the toner container replacement.

It is generally known that the amount of toner movement from the developing device with respect to an electrostatic latent image having the same potential, that is, the amount of toner adhered to the image carrier changes with temperature. 10 ° C 60% RH, 20 ° C 60% RH, 30 ° C 6
Potential 500 “V” under 0% RH environment
The toner adhesion amount per unit area on the image carrier with respect to is shown in FIG. As shown in FIG. 9, when the temperature rises, the amount of toner adhered on the image carrier increases. Therefore, if the toner density is controlled on the basis of the condition of 20 ° C. and 60% RH, the image density at 10 ° C. and 60% RH is controlled. Decreased to 30
When the temperature is 60% RH, there is a problem that the image density is increased and the background is stained.

Therefore, an embodiment of the invention according to claim 8 is to prevent a background stain by suppressing a change in image density due to a temperature change. FIG. 10 shows the configuration of this embodiment, and FIG. 11 shows a part of the processing flow of the image forming apparatus control circuit in this embodiment. In this embodiment, in the embodiment of the invention according to claim 1, as shown in FIG. 10, the temperature sensor 26 as a temperature detecting means for detecting the temperature in the apparatus is, for example, the photosensitive drum 12.
Is disposed in the vicinity of. The temperature sensor 26 detects the temperature inside the device in the vicinity of the photosensitive drum 12, and detects the detected value Vt.
It outputs h to the image forming apparatus control circuit 16.

As shown in FIG. 11, the image forming apparatus control circuit 16 proceeds from step S8 to step S30 to detect the output value Vth of the temperature sensor 26 to detect the temperature inside the apparatus (in-machine temperature), and then to step S30. In step S31, the dot number (pixel number) D of the next written image is corrected to a value D'so that the image density becomes constant based on the temperature. Then, the image forming apparatus control circuit 16 compares D ′ with a predetermined value D ₀ in step S9, determines whether D ′ ≦ D ₀ , and determines D ′.
If ≦ D _{0, the process} proceeds to step S10. If D ′ ≦ D ₀ , the process proceeds to step S12.

As described above, in an embodiment of the invention according to claim 8, in the image forming apparatus according to claim 1, the temperature in the image forming apparatus is detected and the developed image dot number measuring means is detected by the temperature. For detecting the number of writing pixels 2
Temperature sensor 2 as a correction means for correcting the measured value D of 2
6 and the image forming apparatus control circuit 16 are provided, the waiting time after the toner container replacement can be minimized to improve the productivity of the image formed product, and the change in the image density due to the temperature change can be suppressed to prevent the background. It can prevent dirt.
Although the temperature sensor 26 is newly provided in the embodiment of the invention according to claim 8, when the temperature detecting means is provided for performing other process control or the like, the temperature detecting means is used. You may make it use the temperature sensor 26 also.

It is generally known that the amount of toner movement from the developing device with respect to an electrostatic latent image having the same potential, that is, the amount of toner adhered to the image carrier changes with humidity. 20 ° C 30% RH, 20 ° C 60% RH, 20 ° C 9
Potential 500 “V” under 0% RH environment
The toner adhesion amount per unit area on the image carrier with respect to is shown in FIG. As shown in FIG. 12, when the humidity rises, the amount of toner adhered on the image carrier increases. Therefore, if the toner density is controlled based on the condition of 20 ° C. and 60% RH, the image density at 20 ° C. and 30% RH is controlled. Is reduced to 2
At 0 ° C. and 90% RH, there was a problem that the image density was increased and the background was stained.

Therefore, an embodiment of the invention according to claim 9 is to prevent a background stain by suppressing a change in image density due to a change in humidity. FIG. 13 shows the configuration of this embodiment, and FIG. 14 shows a part of the processing flow of the image forming apparatus control circuit in this embodiment. In this embodiment, in the embodiment of the invention according to claim 1, as shown in FIG. 13, a humidity sensor 27 as a humidity detecting means for detecting the humidity in the apparatus is, for example, the photoconductor drum 12.
Is disposed in the vicinity of. The humidity sensor 27 detects the humidity inside the device in the vicinity of the photoconductor drum 12, and detects the detected value Vh.
u is output to the image forming apparatus control circuit 16.

As shown in FIG. 14, the image forming apparatus control circuit 16 proceeds from step S8 to step S32 to detect the output value Vhu of the humidity sensor 27 to detect the humidity in the apparatus (in-machine humidity), In step S33, the dot number (pixel number) D of the next written image is corrected to a value D'so that the image density becomes constant based on the humidity. Then, the image forming apparatus control circuit 16 compares D ′ with a predetermined value D ₀ in step S9, determines whether D ′ ≦ D ₀ , and determines D ′.
If ≦ D _{0, the process} proceeds to step S10. If D ′ ≦ D ₀ , the process proceeds to step S12.

As described above, in one embodiment of the invention according to claim 9, in the image forming apparatus according to claim 1, the humidity in the image forming apparatus is detected, and the developed image dot number measuring means is detected by the humidity. For detecting the number of writing pixels 2
Humidity sensor 2 as a correction means for correcting the measured value D of 2
7 and the image forming apparatus control circuit 16 are provided, the waiting time after the toner container replacement can be minimized to improve the productivity of the image formed product, and the change in the image density due to the change in humidity can be suppressed to prevent the background. It can prevent dirt.
In the embodiment of the invention according to claim 9, the humidity sensor 27 is newly provided. However, when the humidity sensor is provided to perform other process control, the humidity sensor 27 is used. The humidity sensor 27 may also be used.

In an example of the image forming apparatus, a paper passing test of 10K sheets (a test of feeding a transfer sheet to perform an image forming operation) was carried out, and it was found that the unit area on the image carrier with respect to the potential of 500 "V". As shown in FIG. 15, the amount of adhered toner on the image carrier becomes smaller as the number of sheets passed after the developer is replaced in the developing unit (the number of transfer sheets fed: the number of images formed) increases. Therefore, it has been found that if the toner density is controlled based on the condition with a new developer, the toner density will decrease due to an increase in the number of sheets passed after the developer is replaced in the developing section.

In view of the above, according to the tenth aspect of the present invention, by suppressing a decrease in toner density due to an increase in the number of sheets passed after the replacement of the developer in the developing section, a stable image without a decrease in image density over time is obtained. It is intended to obtain density quality. 16 shows the configuration of this embodiment, and FIG. 17 shows a part of the processing flow of the image forming apparatus control circuit in this embodiment. In this embodiment, as one embodiment of the invention according to claim 1, as a sheet passing number measuring means for measuring the number of image formed sheets (sheet passing number) after the developer is replaced in the developing unit as shown in FIG. Paper passing number counting unit 28
The image forming apparatus control circuit 16 sends information about the number of passed sheets from the exchange of the developer in the developing section to the passed sheet number counting section 28.

The sheet passing number counting section 28 counts the sheet passing number after the developer is exchanged in the developing section based on the sheet passing number information sent from the image forming apparatus control circuit 16 after the developer is exchanged in the developing section. The count value Str is output to the image forming apparatus control circuit 16. As shown in FIG. 17, the image forming apparatus control circuit 16 proceeds from step S8 to step S34 to detect the count value Str of the sheet passing number counting unit 28, and in step S35, based on the count value Str, the next writing image The dot number (pixel number) D of is corrected to a value D ′ such that the image density becomes constant.

[0075] Then, the image forming apparatus control circuit 16 'by comparing the predetermined value D ₀ D' D determines whether ≦ D ₀ in step S9, D '≦ D ₀ if not step S1
If 0'and D'≤ D ₀ , the process proceeds to step S12.
When the developer in the developing unit is replaced, the count value of the paper passing number counting unit 28 is reset. This is a method in which a serviceman resets the count value of the paper passing number counting unit 28, or the developer replacing in the developing unit is automatically performed. It is possible to use any of the methods of recognizing the above and resetting the count value of the sheet passing number counting unit 28. If a counter similar to the sheet passing number counting unit 28 is provided for the purpose of maintenance, the counter may also serve as the sheet passing number counting unit 28.

As described above, according to the tenth aspect of the invention, in the image forming apparatus according to the first aspect, the number of sheets passed after the developer is replaced in the developing unit is measured and Since the sheet passing number counting section 28 and the image forming apparatus control circuit 16 as the correction means for correcting the measured value D of the written pixel number detection means 22 as the developed image dot number measurement means are provided, the waiting after the toner container replacement is performed. It is possible to increase the productivity of the image-formed product in the shortest time, and by suppressing the decrease in the toner density due to the increase in the number of sheets passed after the developer replacement in the developing section, the decrease in the image density due to the passage of time can be prevented. It is possible to obtain stable image density quality.

In the embodiment of the invention according to claim 10, the dot number (pixel number) D of the next written image is corrected by the number of sheets passed after the developer is replaced in the developing section. The number of dots (number of pixels) D of the next written image may be corrected depending on the number of sheets passed from the agent exchange and the sheet passing direction.

In an example of the image forming apparatus, the relationship between the driving time of the main motor and the toner adhesion amount on the image bearing member was examined. As a result, the toner adhesion amount per unit area on the image bearing member with respect to the potential 500 “V”. As shown in FIG. 18, the toner adhesion amount on the image carrier decreases as the driving time of the main motor from the developer exchange in the developing section becomes longer. Therefore, the toner density is controlled based on the condition of the new developer. Then, it has been found that the toner concentration decreases due to the increase in the main motor drive time after the developer is replaced in the developing unit.

Therefore, in an embodiment of the invention according to claim 11, a decrease in the toner density due to an increase in the main motor drive time after the replacement of the developer in the developing section is suppressed so that the image density does not decrease with time and is stable. It is intended to obtain image density quality. FIG. 19 shows the configuration of this embodiment, and FIG. 20 shows a part of the processing flow of the image forming apparatus control circuit in this embodiment. In this embodiment, in the embodiment of the invention according to claim 1, as shown in FIG. 19, the main motor drive for measuring the drive time from the developer developer exchange of the main motor for rotating the photosensitive drum 12 and the like. A main motor drive time counting section 29 as a time measuring means is provided, and the image forming apparatus control circuit 16 is provided.
Sends main motor drive time information to the main motor drive time counting section 29 after the developer is replaced in the developing section.

The main motor drive time counting section 29
The main motor drive time from the developer exchange of the developing section is counted based on the main motor drive time information from the developer exchange of the developing section sent from the image forming apparatus control circuit 16, and the count value Stm is used as the count value Stm. Output to. As shown in FIG. 20, the image forming apparatus control circuit 16 proceeds from step S8 to step S36 to detect the count value VStm of the main motor drive time counting section 29, and in step S37, performs the next writing based on the count value VStm. The dot number (pixel number) D of the image is corrected to a value D'so that the image density becomes constant. Then, the image forming apparatus control circuit 16 sets D ′ to the predetermined value D in step S9.
It is determined whether D'≤ D ₀ by comparing with _0, and D'≤ D
If not _{0, the process} proceeds to step S10, and if D ′ ≦ D ₀ , the process proceeds to step S12.

When replacing the developer in the developing section, the count value of the main motor drive time counting section 29 is reset.
This is either a method in which a service person resets the count value of the main motor drive time counting section 29, or a method in which the count value of the main motor drive time counting section 29 is reset by automatically recognizing developer replacement in the developing section. You can use or. When a counter similar to the main motor drive time counting unit 29 is provided for the purpose of maintenance, the counter may also serve as the main motor drive time counting unit 29.

As described above, an embodiment of the invention according to claim 11 is, in the image forming apparatus according to claim 1, a main motor for rotating the photosensitive drum 12 as the image carrier, and a main motor of the main motor. The drive time from the developer exchange of the developing section is measured, and the write pixel number detecting means 22 as the developed image dot number measuring means is measured by the drive time.
Since the main motor drive time counting unit 29 and the image forming apparatus control circuit 16 as the correction means for correcting the measured value D of the image forming apparatus are provided, the waiting time after the toner container replacement is minimized and the productivity of the image formed article is increased. By suppressing the decrease of the toner density due to the increase of the driving time of the main motor after the replacement of the developer in the developing section, it is possible to obtain the stable image density quality without the decrease of the image density with the passage of time.

In an example of the image forming apparatus, the relationship between the driving time of the reading device (scanner) and the toner adhesion amount on the image carrier was examined, and it was found that the potential per unit area on the image carrier was 500 V. Figure 2 shows the toner adhesion amount
As shown in 1, the amount of toner adhered on the image carrier decreases as the scanner driving time from the developer exchange in the developing section becomes longer. Therefore, if the toner density is controlled based on the condition of the new developer, It was found that a decrease in toner concentration occurs due to an increase in the scanner drive time after the developer is replaced in some parts.

Therefore, in an embodiment of the invention according to claim 12, by suppressing the decrease of the toner density due to the increase of the scanner driving time after the replacement of the developer in the developing section, the stable image without the decrease of the image density with the passage of time can be obtained. It is intended to obtain density quality. FIG. 22 shows the configuration of this embodiment,
FIG. 23 shows a part of the processing flow of the image forming apparatus control circuit in this embodiment. In this embodiment, in one embodiment of the invention according to claim 1, as shown in FIG. 22, a scanner driving time counting unit as a scanner driving time measuring unit for measuring a driving time from the developer developing unit exchange of the scanner. The image forming apparatus control circuit 1 is provided with 30.
6 sends the scanner drive time information from the developer exchange in the developing section to the scanner drive time counting section 30.

The scanner drive time counting section 30 counts the scanner drive time from the developer exchange of the developing section based on the scanner drive time information sent from the image forming apparatus control circuit 16 from the developer exchange of the developing section, The count value Sts is output to the image forming apparatus control circuit 16. The image forming apparatus control circuit 16 performs step S as shown in FIG.
8 to step S38, the count value VSts of the scanner drive time counting section 30 is detected, and step S3
At 9, the dot number (pixel number) D of the next written image is corrected to a value D'so that the image density becomes constant based on the count value VSts. Then, the image forming apparatus control circuit 1
6 compares D ′ with a predetermined value D ₀ in step S9, and D ′
≦ D determines whether _0, if ≦ D ₀ 'D proceeds to ≦ D ₀ Otherwise step S10' D Step S12
Proceed to.

When the developer in the developing section is replaced, the count value of the scanner drive time counting section 30 is reset. This is a method in which a service person resets the count value of the scanner drive time counting section 30 or the developer replacement in the developing section. May be automatically recognized to reset the count value of the scanner drive time counting section 30. If a counter similar to the scanner drive time counting unit 30 is provided for the purpose of maintenance, the counter may also serve as the scanner drive time counting unit 30.

As described above, according to the twelfth aspect of the invention, in the image forming apparatus according to the first aspect, the reading device for reading the original image and the driving time of the reading device are measured to measure the driving time. The scanner drive time counting section 30 and the image forming apparatus control circuit 16 as correction means for correcting the measured value D of the written pixel number detection means 22 as the developed image dot number measurement means are provided after replacement of the toner container. It is possible to improve the productivity of image-formed products by minimizing the waiting time of the image formation. By suppressing the toner concentration decrease due to the increase of the scanner drive time after the developer replacement in the developing section, it is possible to stabilize the image density without deterioration over time. The obtained image density quality can be obtained.

In each of the embodiments of the inventions according to claims 1 to 12, it is possible to minimize the waiting time after replacement of the toner container and improve the productivity of the image formed product. It cannot be denied that the quality of the image density is lowered to some extent by minimizing the waiting time. Some users want to prioritize the image density quality over the productivity of the image formed product by minimizing the waiting time after changing the toner container, while giving priority to the productivity of the image formed product rather than the image density quality. It is an undeniable fact that there are users who want to have them do so. Further, even the same user may want to switch between the image density quality and the productivity of the image formed product depending on the situation.

Therefore, in each of the embodiments of the invention according to claim 13, in each of the embodiments of the inventions according to claims 1 to 12, the mode in which the image density quality is prioritized and the productivity of the image formed product are prioritized. Selection means including a changeover switch for switching between the operation modes is provided on an operation panel or the like (not shown). Then, the image forming apparatus control circuit 16
When the mode which prioritizes the productivity of the image formed product is selected by the input signal from the changeover switch, the image forming apparatus is operated as described above, and when the mode which prioritizes the image density quality is selected. In step S5, S ≧
If not S ₀ , the process jumps to step S 3 to operate the image forming apparatus as in the conventional case.

As described above, in each of the embodiments of the invention according to claim 13, in the image forming apparatus according to claim 1, it is selected whether or not the image forming apparatus control circuit 16 as the enabling means is operated. Since the changeover switch is provided as a selecting unit for selecting, the image density quality and the productivity of the image formed product can be selected. Although each of the above embodiments is an embodiment of a digital image forming apparatus including a digital copying machine, the invention according to claims 1 to 13 can be applied to an image forming apparatus such as an analog image forming apparatus, a printer, or a facsimile. You can Further, the inventions according to claims 1 to 13 can be carried out in combination without being used alone.

[0091]

As described above, according to the first aspect of the invention, an image carrier, and a latent image forming means for writing an image on the image carrier by an image signal to form an electrostatic latent image, The electrostatic latent image on the image bearing member is developed with a developer by a developing unit to form a toner image, and the developing unit is replenished with toner from a toner container and the toner container is in a toner end or toner near end state. In an image forming apparatus having a developing device in which the toner container is replaced and prohibiting an image forming operation when the toner container is replaced, the number of developed image dots for measuring the number of dots of the image developed next in the developing section. The number of dots of the image developed next in the developing unit is not more than a predetermined value based on the measurement value of the developed image dot number measurement unit during the image forming operation inhibition time after the replacement of the toner container with the measuring unit. Since a operable means for enabling the image forming operation in some cases, it is possible to the waiting time after the toner container replacement shortest raise the productivity of the image forming material.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the operation enabling means supplies the toner from the toner container to the developing section at least once after the toner container is replaced. Since the image forming operation can be performed after confirming that the operation has been performed, it is possible to minimize the waiting time after the toner container replacement and improve the productivity of the image formed product. It is possible to solve the problem caused by the decrease in toner concentration when the image forming operation is performed without replacing the container.

According to the third aspect of the present invention, in the image forming apparatus according to the first aspect, the operation enabling means enables the image forming operation when the output value of the toner density detecting means satisfies a predetermined condition. Therefore, it is possible to improve the productivity of the image-formed product by minimizing the waiting time after the toner container replacement, and in the case of performing the image forming operation without replacing the toner container in the toner end or toner near end state. It is possible to solve the problem caused by the decrease in toner concentration.

According to a fourth aspect of the invention, in the image forming apparatus according to the first aspect, the means for varying the predetermined value according to the toner replenishment time from the toner container to the developing unit after the toner container is replaced. Since it is provided, it is possible to shorten the waiting time after replacing the toner container and obtain sufficient toner density and image density.

According to the invention of claim 5, in the image forming apparatus of claim 1, the toner density detecting means for detecting the toner density of the developer in the developing section and the output value of the toner density detecting means are used. Since the means for changing the predetermined value is provided, it is possible to shorten the waiting time after the toner container replacement and obtain sufficient toner density and image density.

According to a sixth aspect of the present invention, in the image forming apparatus according to the first aspect, a reading device for reading a document image, and the number of dots of an image provided in the reading device and subsequently developed by the developing section. And the number of dots of the image to be subsequently developed in the developing section based on the measured value of the developed image dot number measuring means during the image forming operation inhibition time after the toner container is replaced. When the value is less than or equal to a predetermined value, the operation enabling means for enabling the image forming operation is provided. Therefore, it is possible to minimize the waiting time after the toner container replacement and improve the productivity of the image formed product. .

According to a seventh aspect of the present invention, in the image forming apparatus according to the first aspect, the memory for expanding the image signal, and the number of dots of an image to be developed next by the developing unit are set to the above-mentioned values. A developed image dot number measuring means for measuring using a memory, and an image developed next in the developing section based on the measured value of the developed image dot number measuring means during the image forming operation inhibition time after the toner container is replaced. When the number of dots is less than or equal to a predetermined value, the operation enabling means for enabling the image forming operation is provided, so that the waiting time after the toner container replacement can be minimized to improve the productivity of the image formed product. It will be possible.

According to the eighth aspect of the invention, in the image forming apparatus according to the first aspect, the temperature inside the image forming apparatus is detected and the measured value of the developed image dot number measuring means is corrected by the temperature. Since the correction unit is provided, it is possible to minimize the waiting time after the toner container is replaced and improve the productivity of the image formed product, and it is possible to suppress the change in the image density due to the temperature change and prevent the background stain.

According to a ninth aspect of the invention, in the image forming apparatus according to the first aspect, the humidity in the image forming apparatus is detected and the measured value of the developed image dot number measuring means is corrected by the humidity. Since the correction means is provided, it is possible to minimize the waiting time after the toner container is replaced and improve the productivity of the image-formed product, and it is possible to suppress the change in image density due to the change in humidity and prevent the background stain.

According to the invention of claim 10, claim 1
In the image forming apparatus described above, the toner container is provided with a correction unit that measures the number of images formed after replacement of the developer in the developing unit and corrects the measurement value of the developed image dot number measuring unit based on the number of images formed. It is possible to increase the productivity of the image-formed product by minimizing the waiting time after the replacement, and it is possible to obtain stable image density quality without deterioration of the image density with time.

According to the invention of claim 11, claim 1
In the image forming apparatus described above, a main motor that rotates the image bearing member, and a drive time of the main motor after the developer is exchanged for the developing unit are measured, and the measured value of the developed image dot number measuring means is measured by the drive time. Since it is possible to improve the productivity of the image-formed product by minimizing the waiting time after the toner container replacement, it is possible to obtain stable image density quality without deterioration of the image density over time. be able to.

According to the invention of claim 12, claim 1
In the image forming apparatus described above, since a reading device for reading a document image and a correction unit for measuring a driving time of the reading device and correcting the measurement value of the developed image dot number measuring unit by the driving time are provided, It is possible to increase the productivity of the image-formed product by minimizing the waiting time after the toner container replacement, and it is possible to obtain stable image density quality without a decrease in image density with the passage of time.

According to the invention of claim 13, claim 1
Since the image forming apparatus described above is provided with the selecting unit that selects whether or not to operate the enabling unit, the image density quality and the productivity of the image formed product can be selected.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the invention according to claim 1.

FIG. 2 is a flowchart showing a part of a processing flow of an image forming apparatus control circuit according to the same embodiment.

FIG. 3 is a flowchart showing a part of a processing flow of an image forming apparatus control circuit in an embodiment of the invention according to claim 2;

FIG. 4 is a flowchart showing a part of a processing flow of an image forming apparatus control circuit in an embodiment of the invention according to claim 3;

FIG. 5 is a flowchart showing a part of a processing flow of an image forming apparatus control circuit in an embodiment of the invention according to claim 4;

FIG. 6 is a flowchart showing a part of a processing flow of an image forming apparatus control circuit according to an embodiment of the invention as claimed in claim 5;

FIG. 7 is a schematic view showing an embodiment of the invention according to claim 6;

FIG. 8 is a schematic view showing an embodiment of the invention according to claim 7;

FIG. 9 is a characteristic diagram showing a relationship between a temperature and an amount of toner adhered to an image carrier in an example of an image forming apparatus.

FIG. 10 is a schematic view showing an embodiment of the invention according to claim 8;

FIG. 11 is a flowchart showing a part of a processing flow of the image forming apparatus control circuit in the embodiment.

FIG. 12 is a characteristic diagram showing a relationship between humidity and an amount of toner adhered to an image carrier in an example of an image forming apparatus.

FIG. 13 is a schematic view showing an embodiment of the invention according to claim 9;

FIG. 14 is a flowchart showing a part of a processing flow of the image forming apparatus control circuit in the embodiment.

FIG. 15 is a characteristic diagram showing the relationship between the toner adhesion amount of the image carrier and the number of passed sheets in an example of the image forming apparatus.

FIG. 16 is a schematic view showing an embodiment of the invention according to claim 10;

FIG. 17 is a flowchart showing a part of a processing flow of the image forming apparatus control circuit in the embodiment.

FIG. 18 is a characteristic diagram showing a relationship between a toner adhesion amount on an image carrier and a main motor drive time in an example of an image forming apparatus.

FIG. 19 is a schematic view showing an embodiment of the invention according to claim 11;

FIG. 20 is a flowchart showing a part of a processing flow of the image forming apparatus control circuit in the embodiment.

FIG. 21 is a characteristic diagram showing a relationship between a toner adhesion amount on an image carrier and a scanner driving time in an example of an image forming apparatus.

FIG. 22 is a schematic view showing an embodiment of the invention according to claim 12;

FIG. 23 is a flowchart showing a part of a processing flow of the image forming apparatus control circuit in the embodiment.

FIG. 24 is a schematic diagram showing a developing unit of an example of a developing device.

FIG. 25 is a front view showing the developing section.

FIG. 26 is a plan view showing the developing section.

FIG. 27 is a characteristic diagram showing measurement results of the relationship between the amount of toner replenished from the toner container to the developing unit and the amount of charge of toner in the developer in the developing device.

[Explanation of symbols]

1, 2 stirring screw 3 Development sleeve 7 Toner supply port 8 Toner density sensor 11 Developing device 12 Photosensitive drum 13 Charger 14 Scanning optical system 15 Laser driver 16 Image forming apparatus control circuit 17 Toner Bottle 18 Transfer paper 19 Transfer separator 20 Cleaning device 21 Write Control Unit 22 Writing Pixel Number Detection Means 23 Reader 24, 25 writing pixel number counting means 26 Temperature sensor 27 Humidity sensor 28 Paper passing count section 29 Main motor drive time counting section 30 Scanner drive time counting section

Front page continuation (72) Inventor Shigeru Watanabe 1-3-6 Nakamagome, Ota-ku, Tokyo, stock company Ricoh (72) Toshitaka Yamaguchi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside the formula company Ricoh (72) Inventor Kenzo Tatsumi 1-3-6 Nakamagome, Ota-ku, Tokyo Shares Company Inside the Ricoh company (72) Takeo Suda 1-3-6 Nakamagome, Ota-ku, Tokyo Inside the formula company Ricoh (72) Inventor Ken Amamiya 1-3-6 Nakamagome, Ota-ku, Tokyo ・ Shares Inside the Ricoh company (72) Mayumi Ohori 1-3-6 Nakamagome, Ota-ku, Tokyo (56) Reference JP-A-2-257167 (JP, A) JP-A-3-161780 (JP, A) JP-A-8-30149 (JP, A) JP-A-8-146751 (JP , A) JP-A-2-162375 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 21/00 370-540 G03G 15/00 303 G03G 15/08-15/08 507

Claims (11)

(57) [Claims] 1. An image carrier, latent image forming means for writing an image on the image carrier by an image signal to form an electrostatic latent image, and an electrostatic latent image on the image carrier by a developing section. A toner image is formed by developing with a developer, the developing unit is replenished with toner from a toner container, and the toner container is replaced when the toner container is in a toner end or toner near end state; In an image forming apparatus which prohibits an image forming operation when a toner container is replaced, a developed image dot number measuring means for measuring the number of dots of an image to be developed next in the developing section, and an image forming operation after the toner container is replaced. An operation that enables an image forming operation when the number of dots of the image developed next in the developing unit is less than or equal to a predetermined value based on the measurement value of the developed image dot number measuring means during the prohibited time And a means, the operative catheter
The stage is before the toner supply from the toner container to the developing unit.
Note that you did at least once after replacing the toner container.
An image forming apparatus, which enables an image forming operation after confirmation . 2. The image forming apparatus according to claim 1, before
From the toner container after the toner container replacement to the developing section
For varying the predetermined value depending on the toner replenishment time
An image forming apparatus comprising the. 3. The image forming apparatus according to claim 1, before
Toner concentration for detecting the toner concentration of the developer in the developing section
The detection means and the output value of this toner density detection means
An image forming apparatus comprising: a unit for changing a predetermined value . 4. The image forming apparatus according to claim 1, wherein the original
A reading device that reads draft images and this reading device
Set the number of dots of the image that is provided and is subsequently developed in the developing section.
Means for measuring the number of developed image dots, and the toner container
After the replacement of the
Based on the measurement value of the image dot number measuring means,
When the number of dots in the image to be developed is less than the specified value
An image forming apparatus comprising: an operation enabling unit that enables an image forming operation . 5. The image forming apparatus according to claim 1, before
A memory for expanding the image signal, and then the developing unit
Measure the number of dots of the image developed by using the memory
Between the developed image dot number measuring means and the toner container
During the image forming operation prohibited time after the conversion,
Based on the measured value of the number of dots measuring means
Image when the number of dots in the image is less than a specified value
An image forming apparatus comprising: an operation enabling unit that enables a forming operation . 6. An image forming apparatus according to claim 1, those
The temperature in the image forming apparatus is detected and the current is detected by the temperature.
Image Corrects the correction means to correct the measured value of the number of dots in the image.
An image forming apparatus characterized by being provided . 7. The image forming apparatus according to claim 1, those
The humidity in the image forming apparatus is detected and the current is detected by the humidity.
Image Corrects the correction means to correct the measured value of the number of dots in the image.
An image forming apparatus characterized by being provided . 8. The image forming apparatus according to claim 1, before
The number of images formed after the developer was replaced in the developing section was measured and
The number of developed images is measured by the above-mentioned developed image dot number measuring means.
An image forming apparatus comprising a correction unit that corrects a constant value . 9. The image forming apparatus according to claim 1, before
The main motor that rotates the image carrier and this main motor
Measure the drive time from the developer replacement of the developing unit
Measurement of the developed image dot number measuring means by the driving time
An image forming apparatus comprising: a correction unit that corrects a value . 10. The image forming apparatus according to claim 1,
Reading device for reading original image and this reading device
The driving time of the developed image is measured according to the driving time.
An image forming apparatus, comprising: a correction unit that corrects the measurement value of the unit number measurement unit . 11. The image forming apparatus according to claim 1,
Selection for selecting whether or not to operate the enabling means
An image forming apparatus comprising the means.