JP2000037905A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an electrostatic latent image from being disturbed even when vibration or impact is applied to an image forming means. SOLUTION: There is disclosed an image forming apparatus comprising an image forming means 4 that forms an image on a recording medium. The image forming apparatus comprises a detecting means 30 for detecting an external force applied to the image forming means 4 and a control means 19 that retries an image forming operation of the image forming means when the detecting means detects based on a detecting signal that the external force is applied to the image forming means 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image forming apparatus such as a copying machine and a laser beam printer.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a laser beam printer as a conventional image forming apparatus. In this laser beam printer, a photoconductor, for example, a photoconductor drum 101 in the apparatus main body 100 is driven to rotate by a driving unit,
2 to be uniformly charged. Also, the scanner 103
A semiconductor laser that emits a laser beam modulated in accordance with an image signal, a polygon mirror that deflects and scans a laser beam from the semiconductor laser, and the like are housed. The laser beam 103a from the scanner 103 is reflected by the reflection mirror 104, is imaged on a uniformly charged surface on the photosensitive drum 101, and scans the photosensitive drum 101 in the main scanning direction to form an image. That is, an electrostatic latent image is formed on the photosensitive drum 101.

[0003] The electrostatic latent image on the photosensitive drum 101 is visualized by a developing device 105 to become an unfixed toner image.
On the other hand, a recording material 107 such as transfer paper is loaded in a cassette 106 mounted in the apparatus main body 100, and together with a print start command input from a computer or the like (not shown), a registration roller 10
9 is fed. The registration roller 109 sends out the recording material 107 at a timing such that the leading end of the image on the photosensitive drum 101 and the leading end of the recording material 107 coincide with each other.

[0004] The toner image on the photosensitive drum 101 is transferred to the recording material 107 by a transfer charger 110, and the accumulated excess charge is removed by a charging needle 111. Pressure roller 113
When the toner image is fixed and the toner image is fixed when the sheet is conveyed, the sheet is discharged to a tray (not shown).
A temperature detecting element, for example, a thermistor 114 is brought into contact with the surface of the fixing roller 112, and the surface temperature of the fixing roller 112 is detected by the thermistor 114.
12 so that the surface temperature of the heater 12 becomes a predetermined temperature.
Is controlled.

Further, the toner and paper dust remaining on the photosensitive drum 101 are removed by a cleaner 116, and the charges remaining on the photosensitive drum 101 are removed by a pre-exposure lamp 117, and the photosensitive drum 101 is charged after uniform charging. It is reused in the process. Here, the photosensitive drum 101, the charger 102, the scanner 103, the reflection mirror 104, the developing device 1
05, cassette 106, paper feed roller 108, registration roller 109, transfer charger 110, charging needle 111, thermal fixing device, cleaner 116, pre-exposure lamp 117
An image forming unit for forming an image on the image 07 is formed.

The control section 118 controls each section of the image forming means to perform the above-described image forming operation, and is connected to the control section 120 by a connector 119. The control unit 120 is connected to a computer (not shown). A polygon mirror in the scanner 103 is rotated by a driving unit, and a laser beam 103a from the scanner 103 scans the photosensitive drum 101 in the main scanning direction. In order to synchronize with an image signal recorded on the drum 101, a laser beam detecting element (not shown) is arranged on the main scanning line of the laser beam 103a, and the laser beam 103a is detected by the laser beam detecting element.
The synchronization light signal output from the laser beam detecting element is output to the control unit 120, and the control unit 12
Numeral 0 outputs an image signal after a lapse of a predetermined time from the synchronization light signal from the laser beam detecting element, and the semiconductor laser is driven by the image signal to emit a laser beam modulated according to the image signal.

[0007]

The above-mentioned laser beam printer may be subject to an impact depending on how the printer is used and installed. Specifically, regardless of whether the image forming operation is being performed or not, the operator may contact the apparatus main body 100 or hit the recording material on the apparatus to align them. However, if excessive vibration or shock is received, the vibration or shock is transmitted to the image forming means, for example, the scanner 103 and the reflection mirror 104, and the photosensitive drum 10
1 is disturbed.

According to the first aspect of the present invention, there is provided an image forming apparatus capable of obtaining a high quality image by re-executing an image forming operation of the image forming unit when an external force is applied to the image forming unit. Aim. According to a second aspect of the present invention, there is provided an image forming apparatus which enables an operator to easily determine that the image quality on a recording material is degraded by an external force when an external force is applied to the image forming means. Aim.

According to a third aspect of the present invention, when an external force is applied to the image forming means, the recording material whose image quality is degraded by the external force is automatically separated from the other recording materials and separated from the other recording materials. It is an object of the present invention to provide an image forming apparatus which can discharge only the recording material on which a high quality image has been formed. It is another object of the present invention to provide an image forming apparatus capable of accurately determining an external force and an internal vibration applied to an image forming unit and preventing a malfunction of a machine.

[0010]

According to a first aspect of the present invention, there is provided an image forming apparatus having an image forming unit for forming an image on a recording material, wherein an external force applied to the image forming unit is controlled. The image forming apparatus further includes a detecting unit for detecting, and a control unit for re-executing an image forming operation of the image forming unit when an external force is applied to the image forming unit by a detection signal of the detecting unit.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the control unit performs an image forming operation when an external force is applied to the image forming unit during the image forming operation of the image forming unit. The fact that image formation is abnormal is additionally formed on the inner recording material.

The invention according to claim 3 is the invention according to claim 1 or 2
In the above image forming apparatus, the recording material after image formation can be selectively discharged to any one of a plurality of places, and the control unit performs image formation when an external force is applied to the image forming unit. Only the recording material during operation is discharged to a predetermined place.

According to a fourth aspect of the present invention, in the image forming apparatus of the first, second or third aspect, the control means is added to the image forming means based on a detection signal level of the detection means for the stored internal vibration. It is to judge external force.

[0014]

FIG. 2 shows a first embodiment of the present invention. The first embodiment is an embodiment of an image forming apparatus including an electrophotographic laser beam printer, and a photoconductor in an apparatus main body 1, for example, a photoconductor drum 2 includes:
It is rotationally driven by the drive unit and is uniformly charged by the charger 3. The scanner 4 contains a semiconductor laser as a light source that emits a laser beam modulated according to an image signal, and a polygon mirror that deflects and scans the laser beam from the semiconductor laser. The laser beam 4a from the scanner 4 is reflected by the reflection mirror 5, is imaged on a uniformly charged surface on the photosensitive drum 2, and scans the photosensitive drum 2 in the main scanning direction. ,
That is, an electrostatic latent image is formed on the photosensitive drum 2.

The electrostatic latent image on the photosensitive drum 2 is
Thus, the image is visualized and becomes an unfixed toner image. On the other hand, a recording material 8 such as transfer paper is loaded in a cassette 7 mounted in the apparatus main body 1, and together with a print start command as an image formation start command input from a control unit described later, a paper feed roller 9 feeds the sheet to the registration roller 10. The registration roller 10 sends out the recording material 8 at a timing such that the leading end of the image on the photosensitive drum 2 and the leading end of the recording material 8 coincide.

The toner image on the photosensitive drum 2 is transferred to the recording material 8 by a transfer charger 11 as a transfer unit, and the accumulated excess charge is removed by a charging needle 12 as a charging unit. When the toner image is fixed by applying heat and pressure when the toner image is nipped and conveyed by the fixing roller 13 and the pressure roller 14 of the heat fixing device, the toner image is discharged to a tray (not shown). A temperature detecting element, for example, a thermistor 15 is brought into contact with the surface of the fixing roller 13 so that the fixing roller 13
Is detected by the thermistor 15, and a temperature control unit (not shown) controls energization of the heater 16 so that the surface temperature of the fixing roller 13 becomes a predetermined temperature based on a detection signal of the thermistor 15.

Further, the toner and paper dust remaining on the photosensitive drum 2 are removed by a cleaner 17 and the photosensitive drum 2 is removed.
The remaining charge is removed by the pre-exposure lamp 18,
The photoreceptor drum 2 is reused in the process after uniform charging.
Here, the photosensitive drum 2, the charger 3, the scanner 4, the reflection mirror 5, the developing unit 6, the cassette 7, the paper feed roller 9, the registration roller 10, the transfer charger 11, the charging needle 12, the thermal fixing device, the cleaner 17, the pre-exposure lamp 18 constitutes an image forming means for forming an image on the recording material 8.

The control unit 19 as a control unit is connected to the control unit 21 by a connector 20 and controls the state of each unit of the image forming unit to perform the above-described image forming operation. The state of each unit is notified to the control unit 21. Conversely, the control unit 21
Is instructed to the control unit 19.

FIG. 1 shows a main circuit configuration of the first embodiment. A laser chip 22 as a semiconductor laser provided in the scanner 4 is driven by an image signal by a laser driving unit 23 as a light source driving unit connected to the control unit 19,
A laser beam modulated according to an image signal is emitted.
The laser beam emitted from the laser chip 22 is
By scanning in the main scanning direction on the photosensitive drum 2 which is reflected by a polygon mirror 25 as a deflection scanner which is rotationally driven by a driving unit 24 composed of a holgon motor and moves in the sub-scanning direction, the photosensitive drum 2 is statically moved on the photosensitive drum 2. An electrostatic latent image 26 is formed.

The reflection mirror 27 reflects the laser beam from the polygon mirror 25 outside the image forming area, and the reflected light 4 ′ from the reflection mirror 27 enters the optical sensor 28. Optical sensor 2
The detector 8 detects the reflected light 4 ′ from the reflection mirror 27 and generates an optical signal. The optical signal is shaped into a waveform by the correction unit 29 and is input to the controller 19. In the first embodiment, an acceleration sensor 30 is provided as detecting means for detecting an external force applied to the scanner 4, that is, vibration and impact. The signal level of the detection signal from the acceleration sensor 30 is amplified by an amplifier 31 and the A / D converter 32
Is converted to a digital value. The control unit 19 takes in digital data from the A / D converter 32 as vibration and shock levels.

The operation panel 33 is connected to the control unit 21 and inputs various commands and performs various displays. The operator issues various commands related to image formation to the control unit 21 via the operation panel 33,
1 and the state of the image forming means, that is, the heat fixing device, the scanner 4, and the like can be known through the operation panel 33. Also,
The horigon motor 24 is driven by a motor drive circuit 34, which is controlled by the control unit 19.

Next, the operation of the control unit 19 will be described with reference to the flowchart shown in FIG. First, when a start command for starting an image forming operation is issued from the control unit 21 to the control unit 19, the control unit 19 controls each unit of the image forming means to perform the image forming operation as described above. Next, the control unit 19 converts the signal level indicating the magnitude of vibration and shock applied to the image forming means from the A / D converter 32 into a digital value between the start and the end of the image forming operation. Start reading.

Thereafter, the control section 19 controls the A / D converter 32
It is determined whether there is a digital value larger than a predetermined value in the digital data from the A / D converter 32. If the digital data from the A / D converter 32 has a digital value larger than the predetermined value, the respective parts of the image forming means are controlled. Then, the same image forming operation as described above (the operation of forming the same image as this time) is performed again.

As the predetermined value in this case, for example, the internal vibration generated by the machine itself (the present embodiment itself) is stored in advance in the storage means of the control unit 21 as an internal vibration signal, and the control unit 19 stores the internal vibration signal. The peak of the internal vibration (peak of the internal vibration signal) stored in the means is A
When the digital data from the / D converter 32 is exceeded, it is determined that an external force has been applied to the scanner 4, and the respective parts of the image forming means are controlled to perform the image forming operation again as described above.

As a result, it is possible to detect even a slight abnormality due to an external force, and it is possible to improve the detection accuracy and to prevent a malfunction of re-executing the image forming operation.
If the digital data from the A / D converter 32 does not exceed the peak of the internal vibration (peak of the internal vibration signal) stored in the storage means, after the recording material is discharged in the current image forming operation, The image forming operation is not performed again.

In the first embodiment, an acceleration sensor 30 as a detecting means for detecting an external force applied to the scanner 4 of the image forming means, and an external force is applied to the scanner 4 of the image forming means by a detection signal of the detecting means. In the case where an external force is applied to the scanner 4 of the image forming unit during the image forming operation, a defective image formation occurs. Also, after the recording material is discharged, an image forming operation of the same content is performed again, so that a high quality image can be obtained.

In the first embodiment, the control unit 19 as a control unit is applied to the scanner 4 of the image forming unit from the detection signal level of the acceleration sensor 30 as the detection unit for the internal vibration stored in the storage unit. Since the external force is determined, the external force applied to the scanner 4 of the image forming means and the internal vibration can be accurately determined, and malfunction of the machine can be prevented.

In the first embodiment, only the external force applied to the scanner 4 of the image forming means is detected by the acceleration sensor 30 as the detecting means. The external force applied to the heat fixing device or the like is determined by the control unit 19 in the same manner as the detection signal from the acceleration sensor 30 from the detection signal, and the same content is again applied to the image forming unit. The image forming operation may be performed.

FIG. 4 shows the operation of the control unit according to the second embodiment of the present invention. In the second embodiment, the first
In the embodiment, when the control unit 19 determines that an external force is applied to the scanner 4, the control unit 19 controls each unit of the image forming unit to cause the image forming unit to perform the same image forming operation again, The additional information indicating that the image is not properly formed and the image formation is abnormal is formed on the recording material. For example, the additional information is sent to the laser driving unit 23 at a predetermined timing, so that the additional information is formed on the photosensitive drum 2. An electrostatic latent image of additional information is also formed, and the additional information is formed in a specific area on the recording material 8.

In the second embodiment, when an external force is applied to the scanner 4 of the image forming unit during the image forming operation of the image forming unit, the control unit 19 as the control unit controls the recording material during the image forming operation. In addition, since an abnormal image formation is added to the image forming unit 8, the operator can easily determine that the image quality on the recording material is degraded by the external force when the external force is applied to the scanner 4 of the image forming unit. Can be.

In the second embodiment, only the external force applied to the scanner 4 of the image forming means is detected by the acceleration sensor 30 as the detecting means. The external force applied to the heat fixing device or the like is determined by the control unit 19 in the same manner as the detection signal from the acceleration sensor 30 from the detection signal, and the same content is again applied to the image forming unit. The image forming operation may be performed, and the fact that the image formation is abnormal may be additionally formed on the recording material 8 during the image forming operation.

FIG. 5 shows the operation of the control unit according to the third embodiment of the present invention. In the third embodiment, the first
In the embodiment, a plurality of recording material discharge ports for discharging a recording material after image formation are provided, for example, two recording material discharge ports A and B are provided, and a recording material discharge port after image formation is provided. A discharge port switching mechanism for discharging to either A or B is provided. If the digital data from the A / D converter 32 does not exceed the peak of the internal vibration (the peak of the internal vibration signal) stored in the storage means,
By controlling the discharge port switching mechanism, the recording material on which an image has been formed by the current image forming operation is discharged to the recording material discharge port A. The control unit 19 also converts the peak of the internal vibration (the peak of the internal vibration signal) stored in the storage unit into an A / D converter 32.
When the digital data from the printer 1 exceeds the digital data, the discharge port switching mechanism is controlled, and an external force is applied to the scanner 4 during the image forming operation to discharge the recording material having the image formation failure to the recording material discharge port B.

In the third embodiment, the recording material after image formation can be selectively discharged to any one of a plurality of places, and the control unit 19 as a control means applies an external force to the image formation means. Is applied, only the recording material during the image forming operation is discharged to a predetermined place, so that when an external force is applied to the image forming means, the recording material whose image quality is deteriorated due to the external force is automatically combined with another recording material. The recording material can be separated and discharged to a place different from other recording materials, and only the recording material on which a high-quality image is formed can be selected.

In the third embodiment, only the external force applied to the scanner 4 of the image forming means is detected by the acceleration sensor 30 as the detecting means. The external force applied to the heat fixing device or the like is determined by the control unit 19 in the same manner as the detection signal from the acceleration sensor 30 from the detection signal, and the same content is again applied to the image forming unit. The image forming operation may be performed, and only the recording material during the image forming operation may be discharged to a predetermined location. In the second embodiment, similarly to the third embodiment,
The recording material after the image formation is configured to be selectively discharged to any one of a plurality of places, and the control unit 19 as a control unit performs recording during the image forming operation when an external force is applied to the image forming unit. Only the material may be discharged to a predetermined place.

[0035]

As described above, according to the first aspect of the present invention, when an external force is applied to the image forming means, the image forming operation of the image forming means is re-executed to obtain a high-quality image. Obtainable.

According to the second aspect of the present invention, with the above configuration, when an external force is applied to the image forming means, the operator can easily determine that the image quality on the recording material is degraded due to the external force. it can.

According to the third aspect of the present invention, when an external force is applied to the image forming means, the recording material whose image quality is degraded by the external force is automatically separated from other recording materials. Can be discharged to a place different from the recording material, and only the recording material on which a high-quality image is formed can be selected.

According to the fourth aspect of the present invention, the external force and internal vibration applied to the image forming means can be accurately determined by the above configuration, and malfunction of the machine can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a main circuit configuration according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing the first embodiment.

FIG. 3 is a flowchart illustrating an operation of a control unit according to the first embodiment.

FIG. 4 is a flowchart illustrating an operation of a control unit according to a second embodiment of the present invention.

FIG. 5 is a flowchart illustrating an operation of a control unit according to a third embodiment of the present invention.

FIG. 6 is a sectional view showing an example of a conventional laser beam printer.

[Explanation of symbols]

 Reference Signs List 2 photosensitive drum 3 charger 4 scanner 5 reflection mirror 6 developing device 7 cassette 7 8 recording material 11 transfer charger 12 charging needle 13 fixing roller 14 pressure roller 19 control unit 22 laser chip 23 laser drive unit 25 multifaceted mirror 30 Acceleration sensor 32 A / D converter

Claims (4)

[Claims] An image forming apparatus having an image forming means for forming an image on a recording material, a detecting means for detecting an external force applied to the image forming means, and an external force applied to the image forming means by a detection signal of the detecting means. Control means for re-executing the image forming operation of the image forming means when the image forming apparatus is added. 2. An image forming apparatus according to claim 1, wherein said control means controls the image formation on a recording material during the image forming operation when an external force is applied to said image forming means during the image forming operation of said image forming means. An image forming apparatus characterized by additionally forming that the formation is abnormal. 3. An image forming apparatus according to claim 1, wherein said recording material after image formation can be selectively discharged to any one of a plurality of locations, and said control means controls said image formation. An image forming apparatus configured to discharge only a recording material during an image forming operation to a predetermined location when an external force is applied to the unit. 4. An image forming apparatus according to claim 1, wherein said control means determines an external force applied to said image forming means from a detection signal level of said detecting means with respect to stored internal vibration. Characteristic image forming apparatus.