JPH05281801A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain an excellent image even in various transfer media such as a plain paper and an OHP sheet. CONSTITUTION:The excellent image is obtained and smooth processing operation is enabled by providing a control means for changing the potential of an electrostatic charger 8 in an image forming device, the output of a transfer device 10 therein, and the various conditions of a solvent remaining rate reducing means 2 for reducing the amount of solvent adhering to the surface of a transfer paper where an unfixed toner image is carried without heat in accordance without the conditions of the various transfer media such as the plain paper and the OHP sheet.

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 using electrophotography. INDUSTRIAL APPLICABILITY The present invention can be suitably used for a printer, a copying machine and the like using a wet electrophotographic method.

[0002]

2. Description of the Related Art In an electrophotographic apparatus, a toner image formed on a photoreceptor by an electrostatic process is transferred to a transfer sheet and fixed in the process of applying heat to the fixed and unfixed toner. Or fuse it to the paper
Needs to be dried. For this reason, the fixing roller and the pressure roller are arranged so as to be in pressure contact with each other across the paper passage of the transfer paper carrying the unfixed toner. The fixing roller, which is in contact with the surface of the transfer paper on which the toner is placed, has a heat source inside and applies heat to the toner image. Further, in the apparatus for performing wet development, when a transfer paper having a low hygroscopic property such as an OHP sheet is used, a large amount of the solvent contained in the toner image remains on the surface of the transfer paper and is pressed against the fixing roller. In order to prevent the toner image from being squeezed out and passing through between the rollers so that a good image cannot be obtained, a good image can be obtained with a small amount of toner on a transfer paper having a good surface smoothness such as an OHP sheet. Is used to reduce the charging potential to reduce the amount of toner transferred to the transfer paper. Further, a step of removing the solvent with a blotter roller is added between the transfer step and the fixing step to reduce the residual ratio of the solvent in the toner and to make the amount of the solvent on the surface of the transfer paper appropriate.

On the other hand, in the case of plain paper, the solvent does not squeeze in the fixing step because the solvent penetrates into the transfer paper even if the charging potential is lowered or the solvent is not removed by the blotter roller. Since the amount of toner or solvent on the surface of the transfer paper is reduced and the density of the solid black portion of the image is lowered, or the uniformity of solid black is deteriorated, the solvent is not reduced by the blotter roller. In this operation mode, the former is OH
In the P mode, the latter mode is set to the plain paper mode, and the method of switching between the two modes is set by the operator by operating the keys of the operation unit, and the transfer paper used by the sensor built into the apparatus is an OHP sheet or a normal paper. There is a method to detect whether it is paper or not and set it.

[0004]

However, in the former method, there is a setting error by the operator, and in the latter method, there is a problem that the sensor is contaminated by paper dust or scattered toner and is erroneously detected. In either case, a good image cannot be obtained (referred to as Problem 1).

Further, in the former method, there is a setting error by the operator, and in the latter method, the transfer paper is OH by the sensor.
Since the charging condition is determined and the charging is started after detecting the P sheet or the plain paper, there is a problem that the start of charging is delayed and an extra printing time is required (referred to as Problem 2). ).

Also, due to an operation error, if the plain paper mode is set even though it is an OHP sheet and the fixing unit is passed,
Not only a good image cannot be obtained, but also the fixing roller and the pressure roller are soiled by the toner that is squeezed out, and the transfer paper after that is soiled, and the life of the roller is shortened (problem 3 and Referred to).

[0007] Also, due to an operation error, OH
If the P sheet mode is set and the solvent is removed by the blotter roller, not only a good image cannot be obtained, but also the blotter roller is unnecessarily soiled (referred to as Problem 4).

An object of the inventions of claims 1 to 6 is to solve problems 1 to 4.

[0009]

The invention according to claim 1 is
It has a solvent residual ratio reducing means for reducing the amount of solvent adhering to the surface of the transfer paper carrying the unfixed toner image in a non-heating manner, and a plurality of operation modes for changing these setting conditions. An image forming apparatus comprising an operation mode input means for setting and a transfer paper type detection means for detecting the type of transfer paper, wherein the operation mode input means
When the mode for reducing the solvent is set and the transfer paper type detecting means detects that the transfer paper is a type to be used without reducing the solvent, the printing operation is interrupted and the operator inputs the operation mode. It is configured to have a processing step of selecting whether to continue the operation in the mode set by the means, to continue in another mode, or to cancel the printing operation.

Further, according to the second aspect of the invention, the toner adhesion reducing means for reducing the amount of toner adhering to the transfer paper and the residual solvent ratio in the toner of the transfer paper carrying the unfixed toner image are non-heated. It has a solvent residual ratio reducing means for reducing and a plurality of operation modes for changing the amount of the solvent adhering to the surface of the transfer paper by changing these setting conditions, and an operation for the operator to set this mode. An image forming apparatus comprising a mode input means and a transfer paper type detection means for detecting a transfer paper type, wherein the transfer paper is set even if a mode in which the solvent is reduced is set by the operation mode input means. When the type detecting unit detects that the transfer paper is a type that is used without reducing the solvent, the mode is switched to a mode in which the solvent is not reduced and the operation is performed.

According to a third aspect of the present invention, the toner adhesion reducing means for reducing the amount of toner adhering to the transfer paper and the residual solvent ratio in the toner of the transfer paper carrying the unfixed toner image are unheated. And a plurality of operation modes for changing the amount of solvent adhering to the surface of the transfer paper by changing these setting conditions,
An image forming apparatus comprising an operation mode input means for an operator to set this mode and a transfer paper type detection means for detecting the type of transfer paper, wherein the operation mode input means reduces solvent. Even if the mode is set, when the transfer paper type detecting unit detects that the transfer paper is of a type in which the solvent is reduced and used, the operation is switched to the mode in which the solvent is reduced.

Further, the invention according to claim 4 is a first reducing means for reducing the amount of the solvent attached to the surface of the transfer paper without heating by reducing the amount of the toner attached to the transfer paper.
Second reducing means for reducing the amount of solvent adhering to the surface of the transfer paper without heating, and a plurality of operations for changing the amount of solvent adhering to the surface of the transfer paper by changing the setting conditions of the first reducing means. An image forming apparatus having a mode, an operation mode input means for an operator to set this mode, and a transfer paper type detection means for detecting the type of transfer paper, wherein the operation mode input means is used to remove a solvent. Is set, and when the transfer paper type detecting means detects that the transfer paper is of a type to be used by reducing the solvent, the setting of the second reducing means is switched to the condition for reducing the solvent. It is characterized by As the first reducing means, a charging potential switching means for switching the level of the charging potential of the photoconductor before exposure can be adopted, and as the second reducing means, a high transfer voltage for transferring from the photoconductor to the transfer paper can be used. A transfer device output adjusting means for adjusting the output of the power source can be adopted.

According to a fifth aspect of the invention, there is provided a solvent residual ratio reducing means for reducing the amount of the solvent adhering to the surface of the transfer paper carrying the unfixed toner image without heating, and a plurality of means for changing the setting conditions. And an operation mode input means for an operator to set the operation mode and a transfer paper type detection means for detecting a transfer paper type. The means sets a mode in which the solvent is not reduced, and when the transfer paper type detection means detects that the transfer paper is of a type in which the solvent is reduced, the printing operation is interrupted and the operator It is configured to have a processing step of selecting whether to continue the operation in the mode set by the operation mode input means, to continue in another mode, or to cancel the printing operation. As the solvent residual ratio reducing means, a charging potential switching means for switching the level of the charging potential of the photoreceptor before exposure and a surface for carrying an unfixed toner image before transfer are moved from a contact state to a non-contact state. It is also possible to combine and use a blotter roller having an oil-absorbing surface. In addition, the transfer paper type detection means starts charging, exposure, and development before detecting the type of transfer paper, and after interruption,
When continuing in any of the above modes, from the beginning,
It is also possible to recharge, expose, and develop again.

Further, in the invention of claim 6, the toner adhesion reducing means for reducing the amount of toner adhering to the transfer paper and the solvent residual ratio in the toner of the transfer paper carrying the unfixed toner image are non-heated. It has a solvent residual ratio reducing means for reducing and a plurality of operation modes for changing the amount of the solvent adhering to the surface of the transfer paper by changing these setting conditions, and an operation for the operator to set this mode. An image forming apparatus comprising a mode input means and a transfer paper type detection means for detecting a transfer paper type, wherein the transfer paper is set even if a mode in which the solvent is reduced is set by the operation mode input means. When the type detecting means sets the mode for reducing the solvent, and when the transfer paper type detecting means detects the type of the transfer paper to be used without reducing the solvent, the solvent residual ratio is low. The setting means and performs the operation by switching the conditions that do not reduce the solvent. As the toner adhesion reducing means, a charging potential switching means for switching the level of the charging potential of the photoreceptor before exposure is used, and as the solvent residual rate reducing means, the contact state with respect to the surface carrying the unfixed toner image before transfer is used. It is also possible to combine and use a blotter roller whose surface that can be moved in a non-contact state is made of an oil absorbing body.

[0015]

According to the first aspect of the present invention, even if the operator sets the OHP sheet by the key operation of the operation unit and starts the image forming operation, the transfer paper using the OHP sheet sensor incorporated in the apparatus is the OHP sheet. If not detected, the operation is interrupted, and it is displayed on the operation unit that the transfer paper used for the set mode is not suitable. Then, among the three operations of restarting the operation in the OHP sheet mode, restarting the operation by switching to the plain paper mode, and canceling the printing operation, the operation selected by the operator by the key operation of the operation unit is performed.

According to the second and third aspects of the present invention, the operator operates the keys on the operation unit to change the plain paper mode to OHP.
The sheet mode is set, the printing operation is started, the OHP sheet sensor incorporated in the apparatus detects the type of the transfer paper used, and when the setting matches the above setting, the printing operation is performed as it is. To do. However, when the type detected by the sensor does not match the above setting, the mode is switched and the printing operation is performed.

According to the fourth aspect of the invention, the OHP sheet sensor incorporated in the apparatus is used even if the operator sets the plain paper mode and starts the printing operation by operating the keys of the operation section. When it is detected that the transfer paper is an OHP sheet, the toner image on the transfer paper is reduced by preventing the transfer of the toner image from the photoconductor to the transfer paper, and the toner amount on the transfer paper is reduced. Try to prevent dirt.

According to the fifth aspect of the invention, even if the operator sets the plain paper mode and starts the printing operation by operating the keys of the operation section, the OHP sheet sensor incorporated in the apparatus is used. When it is detected that the transfer sheet is the OHP sheet, the operation is interrupted and it is displayed on the operation unit that the transfer sheet used for the set mode is not present.

According to the sixth aspect of the invention, even if the operator sets the OHP sheet mode and starts the printing operation by operating the keys of the operation section, the OHP sheet sensor incorporated in the apparatus is used. When it is detected that the transfer paper is not the OHP sheet, the operation is performed without removing the solvent by the blotter roller.

[0020]

Embodiments of the image forming apparatus according to the present invention will be described below. FIG. 1 is a schematic configuration diagram of an electrophotographic copying machine using wet development as an example of an image forming apparatus according to the present invention. In the figure, reference numeral 40 indicates a photoconductor, and around the photoconductor 40, a developing unit 9, a cleaning unit 12, a transfer charger 10, and
Turn roller 11, charging charger 8, static elimination lamp 13
Are arranged respectively. The photoconductor 40 is configured such that the light irradiated by the exposure lamp 7 and reflected by the document surface 42 is irradiated through the optical system to form an electrostatic latent image. The transfer paper from the paper feed box 44 is configured to be transferred by the transfer roller to the registration roller 5 which is temporarily stopped while sandwiching the leading end of the transfer paper. A registration sensor 6 that detects the leading edge of the transfer paper is disposed near the registration roller 5. Further, an OHP sheet sensor 3 for detecting whether the transfer paper is an OHP sheet or a plain paper is provided at a predetermined position of the transport roller. The transfer paper conveyed to the position of the transfer charger 10 via the registration roller 5 is configured such that after the toner is transferred, the visible image is fixed on the transfer paper via the solvent reduction unit 2 and the fixing unit 1. There is. The fixing unit 1 is configured to sandwich the transfer paper between the heat roller 1b and the pressure roller 1b and fix the toner to the transfer paper by heat and pressure.

2 and 3 show an example of the structure of the solvent reduction unit 2. The surface of the blotter roller 2a of the solvent reduction unit 2 is made of a non-woven fabric, an oil absorbent such as felt, synthetic leather, etc. In the plain paper mode, the solenoid 2c is turned off by the microcomputer controlling the device,
It is pulled by the spring 2d and separated from the backup roller 2b (state of FIG. 3) so that the blotter roller 2a and the transfer paper 50 do not come into contact with each other even when the transfer paper 50 passes. On the other hand, in the OHP sheet mode shown in FIG. 2, the solenoid 2c is turned on, and the solvent of the toner image 52 is removed by the blotter roller 2a when the transfer sheet 50 passes.

FIG. 5 shows an example of the structure of the OHP sheet sensor 3. The LED 3a and the photodiode (PD) 3b are coaxially opposed to each other across the paper path, and the PD
The light from the LED 3a is received by 3b. When plain paper is in the paper path, the light from the LED 3a is blocked and cannot be received by the PD 3b. However, even if the OHP sheet is in the sheet passing path, the light from the LED 3a is transmitted and received by the PD 3b.

Next, the operation of this embodiment will be described. When a condition is set by a key of an operation unit (not shown) and copying is started, the transfer paper is conveyed from the paper feed port of the selected paper feed box 44. The registration sensor 6 detects the leading edge of the transfer sheet, and temporarily stops while the leading edge of the transfer sheet is sandwiched by the registration roller 5. Here, the OHP sheet sensor 3 detects whether the transfer paper is an OHP sheet or plain paper. On the other hand, at the same time as the start of copying, the cleaning unit 12 performs pre-cleaning of the photoconductor 40, and when completed, the charging, exposing, developing, cleaning, and neutralizing steps are performed by known methods. At this time, if the OHP sheet mode is selected as the charging condition, the microcomputer controlling the apparatus switches the output of the charging high-voltage power supply driving the charging charger 8 to change the charging potential of the photoconductor 40. Lower than in plain paper mode. At the same time, the output of the lamp regulator that drives the exposure lamp 7 is also switched to reduce the amount of light emitted from the exposure lamp 7 so that proper exposure does not shift.

The transfer paper is fed from the registration roller 5 so that the front end thereof matches the front end of the image, passes through the solvent reduction unit 2 through transfer and separation, and when the OHP sheet mode is selected, the blotter roller 2a transfers the transfer paper. The solvent of the toner image is removed by contacting the surface of the toner. In the plain paper mode, the blotter roller 2a does not come into contact with the transfer paper, so the solvent of the toner image does not decrease. The transfer paper that has exited the solvent reduction unit 2 passes through the fixing unit 1, the toner image is fixed on the transfer paper, and the paper is discharged outside the apparatus.

The LED 3a and the PD 3b are connected to the circuit of FIG. 4, and the LED 3a is constantly lit. When the PD3b receives the light from the LED3a, the output current flows, and the AMP4
It is converted into a voltage by a and the resistor 4b and input to the microcomputer 4c controlling the device. This conversion ratio is selected so that the microcomputer 4c determines a low level when the plain paper is in the sheet passing path and a high level when the OHP sheet is in the sheet passing path. To do. Therefore, when the transfer paper is temporarily stopped by the registration roller 5, the microcomputer 4c reads the signal from the OHP sheet sensor 3, and if it is at a high level, light is transmitted, so the transfer paper is an OHP sheet. At low level, the light is blocked, so the transfer paper is judged to be plain paper. If the transfer sheet is determined to be plain paper by the output of the OHP sheet sensor 3 even though the OHP sheet mode is set by the key operation of the operation unit 60, the microcomputer 4c causes the operation unit 60 to operate. The LED 4d is turned on to display "plain paper". At the same time, the charging, exposure, and development that have already been performed are stopped, the scanner unit is returned to the home position, the cleaning of the photoconductor 40 is completed, and if there is transfer paper that has already been transferred, it is discharged to the outside of the apparatus. To stop the main body drive motor and interrupt the copying operation. At this time, if the operator changes the setting to the plain paper mode by the key operation of the operation unit, the plain paper mode is set, and if the operator does not change the setting, the OHP mode is set and the operation unit 60 is printed. If the key is pressed, the copy operation is performed from the beginning. At this time, as the transfer paper, the transfer paper previously conveyed to the registration roller 5 is used as it is. If the cancel key of the operation unit 60 is pressed during the interruption, the transfer paper that has been conveyed to the registration roller 5 and the transfer paper that has already been fed are also ejected outside the apparatus. Then
The operation ends.

Next, an embodiment of the invention described in claims 2 and 3 will be described. In this embodiment, the configurations of FIGS. 1 to 3 are the same. In this example, the LED 3a and PD 3b are connected to the circuit of FIG. 4 and the LED 3a is always illuminated. PD3b is LED3
When receiving the light of a, an output current flows, is converted into a voltage by the AMP 4a and the resistor 4b, and is input to the microcomputer 4c controlling the device. This conversion ratio is determined by the microcomputer 4c when plain paper is in the paper path.
Is determined to be a low level, and when the OHP sheet is in the sheet passing path, the voltage is determined to be a high level. Therefore, when the transfer paper is temporarily stopped by the registration roller 5, the microcomputer 4c reads the signal from the OHP sheet sensor 3, and if it is at a high level, light is transmitted, so the transfer paper is an OHP sheet. At low level, the light is blocked, so the transfer paper is judged to be plain paper. If this result matches the mode set by the key operation of the operation unit 60, the copying operation is continued as it is. However, even if the OHP sheet mode is set by the key operation of the operation unit 60 and the transfer paper is determined to be the plain paper by the output of the OHP sheet sensor 3, the microcomputer 4c causes the operation unit 60 to operate. The LED 4d is turned on to display "plain paper". At the same time, stop the charging, exposure, and development that have already been performed, return the scanner unit to the home position, switch the conditions of the charging, exposure, and solvent reduction unit to plain paper mode, and perform charging, exposure, and development again from the beginning. Copy under the conditions suitable for the transfer paper. Similarly, when the plain paper mode is set by the key operation of the operation unit 60 and the transfer paper is determined to be the OHP sheet by the output of the OHP sheet sensor 3, the operation unit is operated by the microcomputer 4c. 60
The upper LED 4e is turned on to display "OHP sheet". At the same time, stop the charging, exposure, and development that have already been performed, return the scanner unit to the home position, switch the conditions of the charging, exposure, and solvent reduction unit to OHP sheet mode, and perform charging, exposure, and development again from the beginning. Copy under the conditions suitable for the transfer paper.

Next, an embodiment of the invention described in claim 4 will be described. In this embodiment, the transfer charger 8
Is driven by a microcomputer by a high voltage power source for transfer whose output is turned on / off. The OHP sheet sensor 3 has a structure as shown in FIG. The LED 3a and the photodiode (PD) 3b face downward on the paper passing path so that their optical axes intersect on the transfer paper 50 on the paper passing path.
The angle between the optical axis of a and the surface of the transfer paper 50 is about 90 degrees,
It is possible to employ a device in which the angle between the optical axis of 3b and the surface of the transfer paper 50 is approximately 45 degrees, and the two papers are arranged with a difference between the two angles. In this case, if the plain paper is in the paper path, the surface of the plain paper is uneven, so LE
The light from D3a is diffusely reflected and received by PD3b. However, even if the OHP sheet is in the sheet passing path, the OHP sheet has high transparency and good smoothness, so the LED 3a
Most of the light coming from is transmitted, and the reflected light is also LE.
Since the optical axis of D3a and the surface of the transfer paper are approximately 90 degrees, LED
The light from the LED 3a returns to the PD direction.
You will not be able to receive it at 3b.

In such a structure, the LEDs 3a and P
D3b is connected to the circuit of FIG. 4 and LED3a is constantly illuminated. When the PD 3b receives the light from the LED 3a,
The output current flows, is converted into a voltage by the AMP 4a and the resistor 4b, and controls the device by the microcomputer 4c.
Entered in. This conversion ratio is high when the plain paper is in the paper feed path and the microcomputer 4c is high.
It is determined that the voltage is the level, and when the OHP sheet is on the sheet passing path, the voltage is determined to be the low level. Therefore, when the transfer paper is temporarily stopped by the registration roller 5, the microcomputer 4c reads the signal from the OHP sheet sensor 3, and if the level is low, light is transmitted, so the transfer paper is an OHP sheet. If the level is high, the light is diffusely reflected, so the transfer paper is judged to be plain paper. If the transfer paper is determined to be the OHP sheet by the output of the OHP sheet sensor 3 even though the plain paper mode is set by the key operation of the operation unit 60, the microcomputer 4c operates the operation unit 60 on the operation unit 60. LE
D4d is turned on, and "OHP sheet" is displayed. At the same time, the output of the transfer high-voltage power supply is turned off by the microcomputer 4c so that the toner image on the photoconductor 40 is hardly transferred onto the transfer paper.

Next, an embodiment of the invention described in claim 5 will be described. In this embodiment, the OHP sheet sensor 3 has a structure as shown in FIG. In such a configuration, the LED 3a and the PD 3b are connected to the circuit of FIG. 4, and the LED 3a is constantly lit. When the PD 3b receives the light from the LED 3a, an output current flows and is converted into a voltage by the AMP 4a and the resistor 4b,
It is input to the microcomputer 4c controlling the device. This conversion ratio is determined to be high level by the microcomputer 4c when the plain paper is in the paper passing path, and is low (L) when the OHP sheet is in the paper passing path.
ow) level is selected so that the voltage can be determined. Therefore, when the transfer paper is temporarily stopped by the registration roller 5, the microcomputer 4c reads the signal from the OHP sheet sensor 3, and if the level is low, light is transmitted, so the transfer paper is an OHP sheet. At high level,
Since the light is diffusely reflected, the transfer paper is judged to be plain paper. If the transfer paper is determined to be the OHP sheet by the output of the OHP sheet sensor 3 even though the plain paper mode is set by the key operation of the operation unit 60, the microcomputer 4c operates the operation unit 60 on the operation unit 60. The LED 4d is turned on to display "OHP sheet". At the same time, the charging, exposure, and development that have already been performed are stopped, the scanner unit is returned to the home position, the cleaning of the photoconductor 40 is completed, and if there is transfer paper that has already been transferred, it is discharged to the outside of the apparatus. To stop the main body drive motor from
Stop the copying operation. At this time, if the operator changes the setting to the OHP mode by the key operation of the operation unit, the print key of the operation unit 60 is in the OHP mode if the setting is changed, and if the operator does not change the setting, the print key of the operation unit 60 is set in the plain paper mode. If pressed, the copy operation is performed from the beginning. At this time, as the transfer paper, the transfer paper previously conveyed to the registration roller 5 is used as it is. If the cancel key of the operation unit 60 is pressed during the interruption, the transfer paper that has been conveyed to the registration roller 5 and the transfer paper that has already been fed are also ejected outside the apparatus. Then, the operation ends.

Next, an embodiment of the invention described in claim 6 will be described. In this embodiment, the OHP sheet sensor 3 has a structure as shown in FIG. In such a configuration, the LED 3a and the PD 3b are connected to the circuit of FIG. 4, and the LED 3a is constantly lit. When the PD 3b receives the light from the LED 3a, an output current flows and is converted into a voltage by the AMP 4a and the resistor 4b,
It is input to the microcomputer 4c controlling the device. This conversion ratio is determined to be low level by the microcomputer 4c when the plain paper is in the paper passing path, and is high (Hi) when the OHP sheet is in the paper passing path.
gh) The voltage is selected so as to be judged as the level. Therefore, when the transfer paper is temporarily stopped by the registration roller 5, the microcomputer 4c reads the signal from the OHP sheet sensor 3, and if it is at a high level, light is transmitted, so the transfer paper is an OHP sheet. At low level,
Since the light is blocked, the transfer paper is judged to be plain paper.
When the OHP sheet sensor 3 determines that the transfer paper is plain paper, even though the OHP sheet mode is set by the key operation of the operation unit 60,
LED 4d on the operation unit 60 by the microcomputer 4c
Is lit, and "plain paper" is displayed. At the same time, the solenoid 4c is turned off by the microcomputer 4c so that the blotter roller 2a is separated from the backup roller 2b so that the transfer sheet does not come into contact with the blotter roller 2a even when the transfer sheet passes.

[0031]

According to the first aspect of the present invention, even if the operator mistakenly sets the OHP sheet mode and starts copying when the plain paper is used, the operation is interrupted and the operation unit is operated. Since the fact that plain paper is being used can be displayed, the setting can be biased to the plain paper mode for copying, and operation mistakes can be prevented. Also, even though the OHP sheet is used,
Even if the paper is adhered to the OHP sheet sensor and the light is blocked and it is judged that the paper is plain paper and the operation is interrupted, the operation can be restarted in the OHP sheet mode, and the sensor malfunctions. Even if it is, a good image can be obtained.

According to the second and third aspects of the present invention, if the operator's setting and the used transfer sheet are present, the transfer sheet is conveyed to the registration roller and charging, exposure and development are performed in parallel. It is possible to maintain the high copying speed.
Also, if the operator's setting and the transfer paper used are different, the copying speed will be slower because charging is started after the type of transfer paper is detected, but copying should be performed under the conditions suitable for the transfer paper. You can

According to the invention of claim 4, the operator is
Even if you accidentally set the plain paper mode and start copying when using the HP sheet, the amount of toner transferred to the transfer paper is small, so it is possible to prevent the fixing roller and the pressure roller from becoming dirty. it can.

According to the invention of claim 5, the operator is
When using the HP sheet, even if the plain paper mode is mistakenly set to start copying, the operation is interrupted and the operator is informed that the OHP sheet is being used.
Copying can be performed by changing the setting to the OHP sheet mode, and operation mistakes can be prevented. In addition, even though plain paper is used, even if paper dust or the like adheres to the OHP sheet sensor and the light is blocked, and the operation is interrupted by judging that it is an OHP sheet, the operation will continue in the plain paper mode. Since it can be restarted, a good image can be obtained even if the sensor malfunctions.

According to the sixth aspect of the invention, when the operator uses plain paper, the OHP sheet mode is erroneously set and the blotter roller does not come into contact with the transfer paper. You can prevent it from getting dirty.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a solvent reduction unit.

FIG. 3 is a diagram showing a configuration of a solvent reduction unit.

FIG. 4 is a diagram showing a control circuit according to the present embodiment.

FIG. 5 is a diagram showing a configuration example of an OHP sheet sensor according to the present embodiment.

FIG. 6 is a diagram showing a configuration example of an OHP sheet sensor according to the present embodiment.

[Explanation of symbols]

 1 Fixing Unit 2 Solvent Reduction Unit 3 OHP Sheet Sensor 5 Registration Roller 7 Exposure Lamp 8 Charging Charger 9 Developing Unit 10 Transfer Charger 12 Cleaning Unit 12 Electrification Lamp 40 Photosensitive Body 50 Transfer Paper 60 Operating Section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshito Ikeda 1-3-6 Nakamagome, Ota-ku, Tokyo ・ Inside Ricoh Co., Ltd.

Claims (6)

[Claims] 1. A solvent residual ratio reducing means for reducing the amount of solvent adhering to the surface of a transfer paper carrying an unfixed toner image without heating, and a plurality of operation modes for changing the setting conditions. 1. An image forming apparatus, comprising: an operation mode input unit for an operator to set a mode; and a transfer paper type detection unit for detecting a transfer paper type, wherein the operation mode input unit reduces the solvent. Is set, and when the transfer paper type detection means detects that the transfer paper is a type to be used without reducing the solvent, the printing operation is interrupted and the operator sets the operation mode input means. Whether to continue operating in one mode or another mode
Alternatively, an image forming apparatus having a processing step of canceling or selecting a printing operation. 2. A toner adhesion reducing means for reducing the amount of toner adhering to the transfer paper, and a solvent residual ratio reducing means for non-heatingly reducing the solvent residual ratio in the toner of the transfer paper carrying the unfixed toner image. And a plurality of operation modes for changing the amount of the solvent adhering to the surface of the transfer paper by changing these setting conditions. The operation mode input means for the operator to set this mode, and the transfer paper. An image forming apparatus including a transfer paper type detection unit that detects the type of
Even if the mode for reducing the solvent is set by the operation mode input means, if the transfer paper type detecting means detects the type of the transfer paper to be used without reducing the solvent, the mode does not reduce the solvent. An image forming apparatus, which is switched to perform an operation. 3. A toner adhesion reducing means for reducing the amount of toner adhering to the transfer paper, and a solvent residual ratio reducing means for non-heatingly reducing the solvent residual ratio in the toner of the transfer paper carrying the unfixed toner image. And a plurality of operation modes for changing the amount of the solvent adhering to the surface of the transfer paper by changing these setting conditions. The operation mode input means for the operator to set this mode, and the transfer paper. An image forming apparatus including a transfer paper type detection unit that detects the type of
Even if the mode for reducing the solvent is set by the operation mode input means, if the transfer paper type detecting means detects the type of the transfer paper to be used by reducing the solvent, the mode is switched to the solvent reducing mode. An image forming apparatus, characterized in that the image forming apparatus operates. 4. A first reducing means for reducing the amount of toner adhering to the transfer paper by non-heating to reduce the amount of solvent adhering to the surface of the transfer paper, and the amount of solvent adhering to the surface of the transfer paper. It has a second reducing means for reducing without heating and a plurality of operation modes for changing the amount of the solvent adhering to the surface of the transfer paper by changing the setting conditions of the first reducing means. An image forming apparatus comprising: an operation mode input unit that is set by; and a transfer paper type detection unit that detects the type of transfer paper, the operation mode input unit including:
When a mode in which the solvent is not reduced is set and the transfer paper type detection unit detects that the transfer paper is a type that is used by reducing the solvent, the setting of the second reduction unit is set to the condition for reducing the solvent. An image forming apparatus characterized by switching. 5. A solvent residual ratio reducing means for reducing the amount of solvent adhering to the surface of a transfer paper carrying an unfixed toner image without heating, and a plurality of operation modes for changing the setting conditions. 1. An image forming apparatus comprising: an operation mode input means for an operator to set a mode; and a transfer paper type detection means for detecting a kind of transfer paper, wherein the operation mode input means does not reduce the solvent. Is set, and when the transfer paper type detection unit detects that the transfer paper is a type to be used by reducing the solvent, the printing operation is interrupted, and the operator sets the operation mode input unit. An image forming apparatus having a processing step of selecting whether to continue operation in a mode, continue in another mode, or cancel a printing operation. 6. A toner adhesion reducing means for reducing the amount of toner adhering to the transfer paper, and a solvent residual ratio reducing means for non-heatingly reducing the solvent residual ratio in the toner of the transfer paper carrying the unfixed toner image. And a plurality of operation modes for changing the amount of the solvent adhering to the surface of the transfer paper by changing these setting conditions. The operation mode input means for the operator to set this mode, and the transfer paper. An image forming apparatus including a transfer paper type detection unit that detects the type of
Even if the operation mode input means sets the solvent reduction mode, the transfer paper type detection means sets the solvent reduction mode, and the transfer paper type detection means sets the transfer paper to the solvent. An image forming apparatus characterized in that, when it is detected that the type is to be used without reducing the amount, the setting of the solvent residual rate reducing means is switched to a condition in which the solvent is not reduced, and the operation is performed.