JP2001290315A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device for detecting the presence or absence of the coated layer on a transfer material surface, detecting the thickness of the coated layer and presenting a high quality image recording body based on the optimum image forming condition. SOLUTION: A detector 60 for detecting the coated layer is constituted of an ultrasonic transmitter 61, an ultrasonic receiver 62, and a signal processing part 63 constituted of a control part 71, a high frequency oscillator 73, an amplifier 74, a wave detector 75 and a correction data memory 76 for storing correction data. The ultrasonic transmitter 61 is excited with the high frequency oscillated by the high frequency oscillator 73, and the ultrasonic wave is projected toward the transfer material 80. The wave reflected by the transfer material 80 is received by the ultrasonic receiver 62. The state of a time lag between plural received pulse-shaped reflection waves is detected by the control part 71, then, the presence or absence of the coated layer 81 on the transfer material, the film thickness of the coated layer 81 and the film thickness of the base layer 82 are decided while referring to the correction data stored in the correction data memory 76, and then, the optimum image forming condition suitable to the decision results is set.

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, and more particularly to an image forming apparatus capable of always forming a good image by changing image forming conditions of an image forming mechanism in accordance with the properties of a transfer material for recording an image. Related to the device.

[0002]

2. Description of the Related Art In a current electrophotographic image forming apparatus, a toner image formed on a photoreceptor is transferred onto a transfer material and fixed to record the image. As this transfer material, not only ordinary paper made from wood pulp,
A transparent synthetic resin film (hereinafter referred to as an OHP film) for recording an original image for an overhead projector,
Various types of transfer materials, such as various types of label paper and tack paper, whose surfaces are subjected to resin processing or other processing are used.

[0003] For example, an OHP film for color copying uses a polyester resin (PET) film as a base material, and a coating layer made of a synthetic resin material having the same component as the synthetic resin contained in the toner material on its image recording side surface. Is provided. With this configuration, during the fixing process, the toner is
By being integrally bonded to the film coat layer, the toner image can be firmly fixed to the OHP film and appropriate light transmittance can be ensured.

However, when a toner image is formed on an OHP film without a coating layer, the toner image is not fixed to the OHP film with sufficient strength during fixing processing, and sufficient light transmittance is ensured. Can not.

Further, the above-mentioned coat layer has a property of easily adhering to the pressure roller. For this reason, in the case of an OHP film having a coat layer formed on both the front and back surfaces, during the fixing process, the film surface having the coat layer opposite to the surface on which the toner image is formed is pressed against the pressure roller. And OH
The P film is wrapped around the pressure roller, causing a problem that the OHP film cannot be discharged from the fixing device.

As a countermeasure, OHP films generally have a coat layer formed only on one side.

OH having a coat layer formed only on one side
In the case of the P film, the surface on which the coat layer is formed, that is, O
Since it is necessary to determine the front and back of the HP film, in a conventional image forming apparatus, a notch or a mark is provided at a corner of the OHP film, and this is detected by an optical detecting means to determine the front and back of the OHP film. A number of methods have been proposed and put into practical use (see Japanese Patent Application Laid-Open Nos. 10-329988 and 6-23950).

Further, a method has been proposed in which the light transmittance and light reflectance of the front and back surfaces of an OHP film are measured, and the front and back sides are detected based on the measured values (Japanese Patent Laid-Open No. 8-10618).
No. 9).

[0009]

However, the above-mentioned OH
In the former method in which a notch or a mark is provided at the corner of the P film, the image forming apparatus is provided with a detecting means for detecting the notch or the mark at the corner of the OHP film, for example, only at the leading side in the transport direction. It is common.

For this reason, when the OHP film is loaded in the paper cassette, even if the OHP film is loaded in the paper cassette so that the surface on which the coating layer is formed becomes the image forming surface, notches or marks are detected by the detecting means. If the paper is loaded in the opposite direction to the normal transport direction that can be detected, the notch or the mark does not pass below the detecting means, so that there is a disadvantage that the front and back of the OHP film cannot be determined.

In the latter method of measuring the light transmittance and the light reflectance, the coat layer of the OHP film is formed on a rough surface in advance, and the light reflectance is different between the front surface and the back surface. Therefore, it is necessary to use a dedicated OHP film suitable for this detection method, and there is a disadvantage that the OHP film to be used is limited.

In addition, there is a label paper or a tack paper in which a synthetic resin coat layer is formed on ordinary paper, and a transfer material having such a coat layer formed thereon is subjected to ordinary image forming conditions. However, there is a disadvantage that an appropriate image cannot be formed. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described various problems relating to the presence or absence of a coat layer on the surface of a transfer material.

[0013]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and an invention of claim 1 is an image forming mechanism and a transfer material feeding mechanism for feeding a transfer material toward the image forming mechanism. In the image forming apparatus provided with, a reflected wave of the ultrasonic wave projected on the surface of the transfer material from an ultrasonic transmitter is received by an ultrasonic receiver, and a coat layer on the surface of the transfer material is formed based on the waveform of the received reflected wave. A coat layer detecting means for detecting the thickness of the coating layer, and a control means for setting an image forming condition suitable for the transfer material in the image forming mechanism based on information on the thickness of the coat layer detected by the coat layer detecting means. It is characterized by having.

The coat layer detecting means is a coat layer detecting means for detecting the thickness of the coat layer based on a time difference between a plurality of reflected waves reflected on the boundary surface of the transfer material included in the received reflected wave. is there.

Further, when the detected information on the thickness of the coat layer indicates that there is no coat layer, the control means may perform a warning display and prohibit the operation of the image forming apparatus.

Further, the image forming conditions suitable for the transfer material set in the image forming mechanism by the control means based on the information on the thickness of the coat layer include an exposure condition of the image forming mechanism, a developing condition, and a transfer device output. , Fixing unit output, process speed, attraction output to the transfer material conveying means, and charging output.

[0017]

Embodiments of the present invention will be described below. First, the outline of the configuration of the image forming apparatus will be described.
FIG. 1 is a cross-sectional view illustrating a configuration of an electrophotographic image forming apparatus 100 including a detector that determines the presence or absence of a coat layer on the surface of a transfer material according to an embodiment of the present invention.

In FIG. 1, a document table 11 is disposed on the upper surface of the image forming apparatus 100, and an image reading device 10 is disposed on the lower surface thereof. The image reading device 10 includes a first slider 14 and a second slider 17 that constitute a scanning mechanism, a projection lens 18, and a C disposed at an image forming position of the projection lens 18.
It comprises a CD sensor 19 and a drive mechanism (not shown) for driving the first slider 14 and the second slider 17.

The first slider 14 has an exposure light source 12 for illuminating the original surface and a reflection mirror 13, the second slider 17 has reflection mirrors 15 and 16, and both sliders are on the lower surface of the original table 11. , The second slider 17 is configured to move at half the speed of the first slider 14. Since the driving mechanism has a known configuration and is not related to the subject of the present invention, a detailed description is omitted here.

An image forming mechanism 20 is provided below the image reading apparatus 10.
Is arranged. The image forming mechanism 20 includes a photosensitive drum 21
A charger 22, a laser optical system 23, a mirror 24 for uniformly applying a charge to a photosensitive drum arranged around the photosensitive drum,
A developing device 25, a transfer device 26, a transfer material separating device 27, a cleaning device 28 for removing toner remaining on the photosensitive drum 21 after the toner image is transferred onto the transfer material, and an unnecessary toner remaining on the photosensitive drum 21 And an eraser lamp 29 for removing unnecessary charges. The laser optical system 23 and the mirror 24 project a laser beam modulated by an image signal onto the photosensitive drum 21 to form an electrostatic latent image of the image.

Further, a timing roller 31 is disposed at an end of the photosensitive drum 21 on the transfer material feeding side, and a transport belt 32, a fixing device 33,
A discharge roller 34 and a discharge tray 35 are provided.

Below the image forming mechanism 20, a first transfer material feeding mechanism 40 and a second transfer material feeding mechanism 50 are arranged.

The first transfer material feeding mechanism 40 includes two transfer material cassettes 41 and 42, transfer material rollers 41a and 42a, and a large number of transfer materials arranged along a transfer path for transferring the transfer material toward the timing roller 31. It is composed of transport rollers and the like. The first transfer material feeding mechanism 40 includes a transfer material cassette 4
Detectors 60a and 60b, which determine the presence or absence of a coat layer on the surface of the transfer material, which will be described later, are disposed in close proximity to 1 and 42, respectively.

The second transfer material feeding mechanism 50 includes three transfer material cassettes 51, 52, 53 and paper feed rollers 51a, 52a,
53a, and a number of transport rollers for transporting the transfer material.
Connected to the transport path. In the second transfer material feeding mechanism 50, detectors 60c, 60d, and 60e that determine the presence or absence of a coat layer on the transfer material surface, which will be described later, are disposed close to the transfer material cassettes 51, 52, and 53, respectively. .

It should be noted that two detectors 60a and 60b disposed in the first transfer material feeding mechanism 40 and three detectors 60c and 60 disposed in the second transfer material feeding mechanism 50.
Since d and 60e all have the same configuration, these detectors will be collectively referred to as the detector 60 in the description of the detector described later.

Next, the operation will be briefly described. The original OG placed on the original platen 11 is scanned by a first slider 14 and a second slider 17 constituting a scanning mechanism. The light image of the original OG is formed on the CCD sensor 19, converted into an image signal, subjected to predetermined signal processing, and output to the laser optical system 23.

The laser light modulated by the image signal projected from the laser diode of the laser optical system 23
The light is reflected at 4 and projected onto the photosensitive drum 21 to form an electrostatic latent image of an image. When the electrostatic latent image is moved to the position where the developing device 25 is disposed by the rotation of the photosensitive drum 21 in the direction of the arrow a, the electrostatic latent image is developed by the toner loaded in the developing device 25, and the toner is placed on the photosensitive drum 21. An image is formed.

On the other hand, a transfer material of a predetermined size selected by the operator is fed from the first transfer material feeding mechanism 40 or the second transfer material feeding mechanism 50, and the transfer material is
It is transported to 1 and temporarily stops. The timing roller 31 starts to rotate at the timing when the toner image on the photosensitive drum 21 reaches the transfer position where the transfer device 26 is disposed, and the transfer material is conveyed to the transfer position and The transfer device 26 transfers the toner image to a transfer material.

The transfer material onto which the toner image has been transferred is separated from the photosensitive drum 21 by a transfer material separating device 27, conveyed to a fixing device 33 by a conveying belt 32, and subjected to a fixing process. It is discharged to 35.

Next, the detector 60 will be described. When the transfer material is, for example, an OHP film, a coat layer having a thickness of about 5 to 6 μm is formed on a base layer having a thickness of about 100 μm. Therefore, the thickness of the coat layer on the transfer material surface is detected, and when the film thickness is detected to be a predetermined thickness or more, the surface of the transfer material on which the coat layer is formed has the coat layer formed thereon. It is determined to be a surface. Here, a detector using ultrasonic waves is used as means for detecting the thickness of the coat layer on the surface of the transfer material.

FIG. 2 is a block diagram illustrating the configuration of the detector 60. The detector 60 includes an ultrasonic transmitter 61, an ultrasonic receiver 62, and a signal processing unit 63. The ultrasonic transmitter 61 and the ultrasonic receiver 62 are, for example, an ultrasonic transmitter using a known barium titanate-based piezoelectric conversion element,
An ultrasonic receiver can be used.

The signal processing section 63 is mainly composed of a control section 71 composed of a CPU 72. The input / output ports of the CPU 72 include a high-frequency oscillator 73, an amplifier 74, a detector 7
5. A calibration data memory 76 storing calibration data is connected.

The high-frequency signal output from the high-frequency oscillator 73 operating under the control of the control unit 71 is transmitted to the ultrasonic transmitter 61.
, And ultrasonic waves are projected in a pulse shape toward the transfer material 80. The pulse-like reflected wave reflected by the transfer material 80 is received by the ultrasonic receiver 62, detected by the detector 75 via the amplifier 74, and input to the control unit 71. As described later, a plurality of ultrasonic pulse reflected waves reflected from the transfer material 80 with a certain time delay are received by the ultrasonic receiver 62.

The control unit 71 detects a state of time delay between the plurality of received pulsed reflected waves, and refers to the calibration data stored in the calibration data memory 76 to coat the transfer material 80. The thickness of the layer 81 and the thickness of the base layer 82 are determined.

FIG. 3 is a diagram for explaining how to measure the film thicknesses of the coat layer 81 and the base layer 82 of the transfer material 80 by using an ultrasonic pulse emitted toward the transfer material 80.

Since the ultrasonic wave has a property of being reflected at the boundary between two substances having different acoustic characteristics, when the ultrasonic wave is emitted from the ultrasonic transmitter 61 toward the transfer material 80, the reflected wave includes: Coat layer 81 formed on the surface of transfer material 80
A reflected wave R1 reflected on the upper surface of the substrate, a reflected wave R2 propagating inside the coat layer 81 and reflected on the boundary surface between the coat layer 81 and the base layer 82, and a reflected wave R2 passing through the base layer 82 and on the back surface of the base layer The three reflected waves, including the reflected wave R3, are received by the ultrasonic receiver 62.

FIG. 4 shows the reflected waves R1, R2, R3 described above.
Fig. 7 is a diagram for explaining the relationship between the reception times, and it is assumed that ultrasonic waves are emitted from the ultrasonic transmitter 61 toward the transfer material 80 at time T0.

The reflected wave R1 reflected on the upper surface of the coat layer 81
Assuming that the time when is received by the ultrasonic receiver 62 is the reference time T1, the reflected wave R2 that propagates inside the coat layer 81 and is reflected at the boundary surface between the coat layer 81 and the base layer 82 at the reference time T1 On the other hand, it is received at time T2 which is delayed by time t12.

The reflected wave R3 that has passed through the base layer 82 of the transfer material 80 and has been reflected on the back surface of the transfer material 80 has a time T3 that is delayed by a time t23 from the time T2 when the reflected wave R2 was received.
(Time T delayed from reference time T1 by time t13)
Received in 3).

The time delay t12 with respect to the reference time T1 when the reflected wave R2 is received is a value related to the thickness TC of the coat layer 81, and the time delay t23 with respect to the received time T2 of the reflected wave R2 when the reflected wave R3 is received is Thickness TB of base layer 82
Is the value associated with

Therefore, for a plurality of sample transfer materials in which the thickness TC of the coat layer 81 and the thickness TB of the base layer 82 are different from each other, the thickness TC of the coat layer 81 and the thickness TB of the base layer 82 are separately determined. It is precisely measured by means, for example, observing a cross section of the transfer material with a microscope.

Next, ultrasonic waves are emitted from the ultrasonic transmitter 61 toward the transfer material 80 for a plurality of sample transfer materials for which the thickness TC of the coat layer 81 and the thickness TB of the base layer 82 are known. The reflected wave is received by the ultrasonic receiver 62, and the time delay t12 from the reference time T1 to the time T2 when the reflected wave R2 is received, and the reflected wave R3 is received from the time T2 when the reflected wave R2 is received. The measured time delay t23 until time T3 is measured to collect calibration data, and a calibration curve showing the relationship between the thickness and the time delay is created.

FIG. 5 shows the time delay t12 of the reception time T2 of the reflected wave R2 with respect to the reference time T1 and the thickness TC of the coat layer 81.
6 is an example of a calibration curve showing the relationship of
7 is an example of a calibration curve showing the relationship between the time delay t23 of the reception time T3 of the reflected wave R3 with respect to the reception time T2 of the second embodiment and the thickness TB of the base layer 82.

When the above preparation is completed, the ultrasonic wave is emitted from the ultrasonic transmitter 61 toward the transfer material for the transfer material whose thickness of the coat layer and the base layer is not known, and the ultrasonic receiver 62 Then, the reception time T2 of the reflected wave R2 with respect to the reference time T1 of the reflected wave received at time t1, and the reception time T3 of the reflected wave R3 with respect to the reception time T2 of the reflected wave R2 are measured, and the time delay t12 and the time delay t23 are determined.

Next, the thickness TC of the first layer is obtained from the time t12 with reference to the calibration curve shown in FIG. 5, and the thickness TC of the second layer is obtained from the time t23 by referring to the calibration curve shown in FIG. Find TB. If the thickness TC of the first layer is within a predetermined range, it is determined that the first layer is a coat layer, and if the thickness TB of the second layer is within a predetermined range, the second layer is a base layer. Is determined. When the thickness TC of the first layer is considerably smaller than a predetermined range, it can be determined that the coat layer is not formed.

Here, the thicknesses of the base layer and the coat layer of the transfer material will be described. In the case of a typical OHP film, the thickness of the base layer is about 100 μm, and the thickness of the coat layer is about 5 to 6 μm. In a typical coated paper, the thickness of the base layer is about 80 μm, and the thickness of the coat layer is about 40 to 5 μm.
It is in the range of 0 μm.

For label paper and tack paper, 90 μm
A seal material (coat layer) having a thickness of about 100 μm on a mount (base layer) of about
For example, a seal material (coat layer) having a thickness of about 60 μm is formed on a mount (base layer) of about m.

In the above description, the detector 60 for detecting the thickness of the coat layer has been described as being arranged close to the transfer material cassette. However, the detector 60 can also be provided, for example, in the middle of the transport path. Detector 60
In an image forming apparatus, when an image is formed on a transfer material by an image forming mechanism of an image forming apparatus, if the thickness of a coat layer can be detected on the image forming surface side, there is no limitation on the arrangement position.

Next, control of an image forming operation when a coat layer is detected on the image forming surface side of the transfer material will be described. Here, the control is performed when a transfer material having a coat layer formed on one of the front and back surfaces is loaded in the transfer material cassette, and the transfer material having no coat layer formed on both the front and back surfaces is used. When is loaded, normal control is performed.

When it is determined that the coat layer is present on the image forming surface side of the loaded transfer material, the transfer material is conveyed to an image forming mechanism, and an image is formed under predetermined image forming conditions corresponding to the coat layer. . Further, when it is determined that there is no coat layer on the image forming surface side, conveyance of the transfer material to the image forming mechanism is prohibited,
A warning is displayed and the system enters the standby state. Thereafter, when it is detected that the transfer material has been replaced or exchanged,
Again, the process returns to the determination as to whether there is a coat layer on the image forming surface side.

In the case of an image forming apparatus provided with a reversing mechanism for reversing the front and back of the transfer material, when it is determined that there is no coat layer on the image forming surface side, the transfer material is transported to the reversing mechanism and the front and back are transferred. And then transported to the image forming mechanism.

Next, setting of image forming conditions when a coat layer is detected on the image forming surface side of the transfer material will be described. If the transfer material has a coat layer, image forming conditions according to the thickness and material of the coat layer, that is, exposure conditions of the image forming mechanism,
An optimum image can be formed by changing the development conditions, the output of the transfer device, the output of the fixing device, the process speed, the suction output to the transfer material conveying means, the charging output, and the like.

The setting of the optimum image forming conditions according to the thickness and the material of the coat layer is performed by selecting the type of the transfer material, ie, the OHP film,
Image forming conditions can be determined in advance based on the type, thickness, material, etc. of the transfer material such as label paper, tack paper, normal thick paper, plain paper, etc. By inputting the thickness, the material, and the like, the optimum image forming conditions according to the transfer material can be automatically set.

In the embodiment of the present invention described above,
Although the ultrasonic transmitter and the ultrasonic receiver are separately provided, they may be constituted by one ultrasonic transceiver.

[0055]

As described above in detail, according to the first aspect of the present invention, an ultrasonic wave is transmitted from an ultrasonic transmitter to a transfer material surface, and the ultrasonic wave is received by an ultrasonic receiver. The waveform, specifically, the thickness of the coat layer on the transfer material surface is detected based on the time difference between the received reflected waves, and image forming conditions suitable for the transfer material based on information indicating the thickness of the coat layer,
That is, values such as exposure conditions, development conditions, transfer device output, fixing device output, process speed, suction output to the transfer material conveying means, and charging output of the image forming mechanism are set in the image forming mechanism. When there is no coat layer, a warning is displayed and the operation of the image forming apparatus is prohibited.

Thus, in the case of a transfer material having a coat layer formed on its surface, for example, OHP film, label paper, tack paper, etc., the coat layer is formed regardless of the loading direction of the transfer material loaded in the transfer material cassette. The transferred surface can be easily determined without contact, and there is no need to process the surface of the transfer material into a rough surface.

Furthermore, since not only the presence or absence of a coat layer of the transfer material but also the thickness of the coat layer can be detected, a high-quality image can be formed under optimum image forming conditions according to the thickness of the coat layer and the type of transfer material. A recording can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an electrophotographic image forming apparatus.

FIG. 2 is a block diagram illustrating a configuration of a detector.

FIG. 3 is a view for explaining how to measure the thickness of a coat layer on the surface of a transfer material using ultrasonic waves.

FIG. 4 is a diagram for explaining the relationship between reception times of reflected waves R1, R2, and R3.

FIG. 5 is a reception time T of a reflected wave R2 with respect to a reference time T1.
The figure which shows an example of the calibration curve which shows the relationship between the time delay of 2 and the thickness of a coat layer.

FIG. 6 shows a reflected wave R3 with respect to a reception time T2 of the reflected wave R2.
The figure which shows an example of the calibration curve which shows the relationship between the time delay of the reception time T3 of FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 10 image reading device 11 platen 14 first slider 17 second slider 20 image forming mechanism 21 photosensitive drum 40 first transfer material feeding mechanism 41, 42 transfer material cassette 50 second transfer material feeding mechanism 51, 52, 53 Transfer material cassette 60, 60a, 60b, 60c, 60d, 60e Detector 61 Ultrasonic transmitter 62 Ultrasonic receiver 63 Signal processing unit 71 Control unit 72 CPU 73 High frequency oscillator 74 Amplifier 75 Detector 76 Calibration data memory 80 Transfer material 81 Coat layer 82 Base layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiyuki Sahara 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Haruhiko Hori Azuchi-cho, Chuo-ku, Osaka-shi, Osaka 2-3-1-3 Osaka International Building Minolta Co., Ltd. F-term (reference) 2F068 AA28 AA46 BB17 CC00 FF03 FF12 FF25 KK14 QQ45 2H027 DC02 EA01 EA02 EA03 EA04 EA12 EA18 FB07 FB15 GB07 9A001 BB04 HZ34 JJ35 KK

Claims (4)

[Claims] 1. An image forming apparatus comprising: an image forming mechanism; and a transfer material feeding mechanism for feeding a transfer material toward the image forming mechanism. A coat layer detecting means for receiving a reflected wave of a sound wave by an ultrasonic receiver and detecting a thickness of a coat layer on the surface of the transfer material based on a waveform of the received reflected wave; and a coat layer detected by the coat layer detecting means. A control unit for setting image forming conditions suitable for the transfer material in the image forming mechanism based on information on the thickness of the image forming apparatus. 2. The method according to claim 1, wherein the coat layer detecting unit detects a thickness of the coat layer based on a time difference between a plurality of reflected waves reflected on a boundary surface of the transfer material included in the received reflected wave. The image forming apparatus according to claim 1, wherein: 3. The image forming apparatus according to claim 1, wherein when the detected information on the thickness of the coat layer indicates that there is no coat layer, the control unit displays a warning and inhibits the operation of the image forming apparatus. The image forming apparatus as described in the above. 4. An image forming condition suitable for a transfer material set in the image forming mechanism by the control means based on information on a thickness of the coat layer includes an exposure condition of the image forming mechanism, a developing condition,
2. The image forming apparatus according to claim 1, further comprising at least one of a transfer unit output, a fixing unit output, a process speed, a suction output to a transfer material conveying unit, and a charging output.