JPS5862663A - Electrostatic recording device of transfer system - Google Patents

Abstract

PURPOSE:To reduce the fatigue of a photoreceptor, by changing the discharge current of a discharger or/and the irradiation light from post-development and pre-transfer lamp for exposure of the photo-receptor to the surface of the photoreceptor by the detection signal of the potential of the surface of the photoreceptor before the development to separate a transfer paper stably with a separating electrode even if originals are changed. CONSTITUTION:The discharge current of a separating electrode 2 is controlled on the basis of the detection output of a detector 10 for the potential of the surface of a photoreceptor to separate a transfer paper stably even if an original is changed to a photographic original or a character original. Meanwhile, under a constnt condition where the discharge current is >=140muA, a pre-transfer exposure lamp 15 is lit or the quantity of light of this lamp is increased when the potential of the surface of the photoreceptor detected by the detector 10 exceeds a certain value. When the potential of the surface of the photorecptor is a certain voltage or less, a switch S is switched to a resistance RA to set the quantity of light of the lamp 15 to 15 luxsec; and when this potential is higher than the ceertain voltage, the switch S is switched to a resistance R to set the quantity of light of the lamp to 30luxsec.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an electrostatic recording device equipped with a corona discharger for separating transfer paper or a lamp system for exposing a photoreceptor after development and before transfer. In an electrostatic recording device, a pre-transfer exposure lamp irradiates the surface of the photoreceptor on which toner has been developed under the condition that even if the original changes, the transfer paper changes, and so on, a corona discharger for separating the transfer paper, i.e. It was like a separation electrode that discharged electricity against the back side of the transfer paper.

The electrostatic recording device #, which uses a general VC1 separation electric current to separate the transfer paper, has a separation means in contact with the W photoreceptor, compared to a transfer electrostatic recording device that uses separation claws or a separation belt. Since there are no scratches on the photoreceptor, it has the excellent feature of not causing scratches on the photoreceptor or causing part of the toner image to be lost. However, traditional separation′砿! In an electrostatic recording device using #, when the original is changed, separation may not be performed stably or the transfer rate of the toner image may become unreliable.

In order to solve the above-mentioned melting problem, the present invention has been made based on an investigation into the cause.

For example, when the original is a photographic original, the area ratio of the part with a high surface potential of the photoreceptor is large, and when the original is a text, the area ratio of the part with a good surface potential of the photoreceptor is small. If the irradiation conditions of the transfer #exposure lamp and the discharge conditions of the separation pole are constant, one separation will not be performed with the same VC reliably.
Differences will also occur in the transfer efficiency of the toner image.Table 7 shows differences in the surface potential of the photoreceptor before toner development and separation of the transfer paper, which occurs when the original is changed, as described above. The relationship between the difficulty and the discharge voltage fIft of the separation electrode is
The results of the investigation by changing ¥r are 0. In addition, the photoconductor KFi
Although the se-'re system was used, the current emitted by the transfer electrode in this experiment was 3θμA (D, C).

Table/ Photoreceptor surface potential and separation characteristics (Note) 0, XU, respectively, weight thickness sr) F/II
r2) A This shows that the transfer paper transferred to 4t size was completely separated, and that the transfer paper was completely separated.

The results in Table 7 show that even if the surface potential of the photoreceptor changes greatly due to changes in the original, if the discharge radio waves of the separation me are changed according to Therefore, the separation electrode 771
Figures 1 and 12 show the results of a more detailed investigation of the shadow of sweat vK in the city.

In FIGS. 1 and 2, %v1 and v2 are, as shown in FIG. This is the surface potential of the lower photoreceptor 3.

FIG. 1 shows the results when the photoreceptor surface potential in Table 1 is 6θOV, and FIG. 12 similarly shows the results when the photoreceptor surface potential is /0OV.

When compared with the measurement results in Figure 1 and the results in Table 1, it can be seen that the surface potential v1 of the transfer paper on the ridge of the separation electrode 2 is approximately equal to the surface potential v2 of the photoreceptor below it. The transfer paper / becomes completely separated when the potentials are the same, and complete separation occurs when there is a relative potential difference between the surface potentials Vl and V2. I know that it won't happen. What can be considered from the above is that the reason why the transfer paper is attracted to the photoreceptor 3 in FIG. This is because the charge on the transfer paper is the cause of preventing the separation of the transfer paper L, and the difference between the surface potential v1 of the transfer paper L and the surface potential v2 of the photoreceptor 30 below it. This is the cause of the relative potential difference, and when this charge is dissipated by the separation electrode, the transfer paper l becomes like a conductive material, the electrostatic adsorption of the transfer paper l is released, and separation occurs. This means that it will be carried out. In other words, the separation of the transfer paper is more closely related to the surface potential of the photoreceptor after development than to the surface potential of the photoreceptor before toner development due to the influence of the discharge radio waves of the separation electrode. It is clear from the results in Table 1 that stability in transfer paper separation can be obtained even if the discharge current is controlled in relation to the previous photoreceptor surface potential. Regarding the relationship with the surface potential of the photoconductor after polishing and before transfer, the surface potential of the KPIA photoconductor decreases when exposed to light on the lower side. Therefore, naturally, the difficulty of separating the transfer paper 1-1 should change due to pre-transfer exposure. It is.

Table 2 shows whether the results in Table 1 are 'R' due to pre-transfer exposure.゛The surface of the photoreceptor is illuminated with 3θlux Bθ by a cold-tone camellia fluorescent tube with peak
Showing the difficulty of separating the transfer paper when irradiated with the light intensity of C 0 The photoreceptor and transfer paper conditions are of course the same as in Table 2 Table 2 Separation characteristics during pre-transfer exposure From the results of Table 2 As is clear, 30 lux sea
By performing pre-transfer shock light, it is possible to completely separate the transfer paper even for photographic originals under the same conditions as for text originals. However, since pre-transfer exposure causes optical fatigue on the photoreceptor, it is necessary to reduce the amount of light as much as possible even if it is performed.

The figure 1H4 shows the photoreceptor surface potential before the side light of the charged original image under the same conditions when the pre-transfer exposure is not performed and when the pre-transfer exposure is performed under the same conditions as in the table. K
Therefore, the feeling of fatigue that changes 5? and JOlux
It can be seen that the photoreceptor is considerably fatigued by pre-transfer exposure of snc. In this figure, a Se-Te photoreceptor is used as the photoreceptor. Table 3 shows the relationship between the pre-transfer exposure amount and the transfer paper separation success rate for Al size transfer paper of various thicknesses, and Table 3 shows the relationship between the pre-transfer exposure amount and the transfer efficiency, that is, the development In Table 1 and Table 31, which show the relationship between the ratio of the amount of transferred toner to the amount of toner, the same conditions as in Table 2 were used for the photoconductor and the pre-transfer exposure lamp, and the discharge current of the separation electrode was set to Yr/JθAA. others,#! Transfer electrode shown in Figure 3! The discharge current of O is set at 30 μA.
Further, the thickness of the transfer paper on the front side is aty/1II2.

Table 3 Pre-transfer tube light amount and separation success rate table Pre-transfer exposure amount and transfer efficiency As can be seen from Table 3, depending on the thickness of the transfer paper, even a small pre-transfer exposure amount can be sufficient to improve VC separation. In addition, as can be seen from Table 9, even a small pre-transfer exposure amount has an effect equivalent to K11l in improving transfer efficiency.The present invention was made based on the above results, and the present invention The transfer type electrostatic recording device # has a corona discharger tft for separating the transfer paper, and an electrostatic discharge device t equipped with a lamp for exposing the photoreceptor after development. 0 characterized in that the surface potential of the photoreceptor before snow is detected and the discharge current of the discharger and/or the light irradiated onto the surface of the photoreceptor by the lamp can be changed based on the detected signal. Below, the present invention will be explained! This will be explained with reference to FIGS. 2 and 2. FIG. 3 is a schematic configuration diagram of a recording apparatus of the present invention in which the discharge current of the separation electrode is controlled by detecting the surface potential of the photoreceptor after exposure of the original th image. , @Figure 4 is a schematic configuration diagram of the recording apparatus of the present invention in which the amount of light irradiated on the photoreceptor by the lamp for pre-transfer exposure is adjusted to the full, and Figure 7 is a partial diagram of the light amount control circuit of the lamp for pre-transfer exposure. 0 In FIG. 3 and FIG. /λ is a control signal generation circuit that outputs a control signal according to the detection information of the detection sensor 10;
A delay circuit /3 delays the control signal of the control signal generating circuit // by the time until it reaches the position of the light lamp /j, and /3 controls the AC voltage application circuit /da based on the output signal of the delay circuit /-. , discharger R in separation area S- or pre-transfer exposure run 1/! This is a control circuit that changes the irradiation scene on the photoreceptor surface.

Note that the reason for applying AC voltage to the separation electrode λ to start the discharge is to ensure that static electricity is removed from the tip of the transfer paper.
Taking into account variations in the transfer timing of the transfer paper and delays in the rise of discharge, etc., the transfer is performed before the leading edge of the transfer paper reaches the transfer electrode j. By controlling the discharge gL flow of the separation electrode 2 to a value that gives the result marked 0 in Table 1 based on the detection of the surface potential of the photoreceptor by the sensor 10, even if the original changes between a photo original and a text original, I will put it in place and transfer it, (
・Preliminary separation will be carried out. In the recording device shown in FIG. 6, the separation electrode 2 is set to a constant condition in which the discharge current is 0 μA or more, and the detection sensor 1 is activated.

If the pre-transfer exposure lamp lj is turned on when the photoconductor surface potential detected by is above a certain level, or the light intensity of the pre-transfer exposure lamp is is increased as the photoconductor surface potential decreases, Table 2 As shown in Table 3, the stability of transfer paper separation can be completely improved, and as shown in the table, the transfer efficiency can also be improved.

Figure 2 shows the front transfer light lamp/! This figure shows an example of an AC voltage application circuit in which the light intensity is switched and controlled in λ stages.The control circuit 3 in Fig. 2 switches the selector switch S to the resistor Rm when the photoreceptor surface potential is below a certain voltage. W-Continue with the pre-transfer exposure lamp/! The irradiation light I/! iux sea, and when the voltage becomes higher than -, switch the selector switch S to resistor Rm and turn it off. The amount of irradiation light is 3θlux
As described above, according to the present invention, it is possible to stably separate the transfer paper using the separation electrode regardless of changes in the original, and also ( Even when using a 4-front exposure lamp, fatigue of the photoreceptor can be minimized.

In the present invention, a plurality of potential detection sensors may be used, and they may be arranged not only in the width direction of the photoreceptor but also in the longitudinal direction. Furthermore, a fluorescent lamp or an incandescent lamp other than a cold cathode fluorescent tube may be used as the pre-transfer/side light lamp.

Furthermore, the amount of light irradiated onto the photoreceptor may be changed using a filter without changing the amount of light from the rc1 lamp.

[Brief explanation of drawings]

Figures 1 and 2 are graphs showing the influence of the separation electrode discharge current on transfer paper separation, respectively, and Figure 3 is a graph showing the measurement positions in Figures 1 and 1 of the transfer type electrostatic charge. A partial side view of the recording device, the second figure is a graph showing photoreceptor fatigue due to pre-transfer exposure, and the second figure is a graph showing the fatigue of the photoreceptor due to pre-transfer exposure. Recording device #, Q general configuration diagram, Figure 2 is a partial diagram of the light amount control circuit of the pre-transfer exposure lamp.
Photoreceptor! ... Transfer electrode, l... Toner developing pupil, /σ... Detection sensor, //... Control signal generation circuit, /J +++ delay circuit, /3... Control circuit, /4t. ...AC voltage application circuit. /! ...Pre-transfer exposure lamp.

Claims (1)

[Claims] In an electrostatic recording device equipped with a corona discharger for separating the transfer paper or a lamp for exposing the photoreceptor after image transfer and before image intensification, the surface potential of the photoreceptor is detected after projection of the original image and before image intensification; Transfer type electrostatic recording device 0 characterized in that it is configured to be able to change the discharge current of the discharger and/or the illumination a+ applied to the surface of the photoreceptor by the lamp based on the detection signal.