JPS5862676A - Transfer type electrostatic recording device - Google Patents

Abstract

PURPOSE:To transfer and separate stably transfer forms different in thickness and prevent the degradation of a photoreceptor, by changing the irradiation light from a pre-transfer exposure lamp to the photoreceptor on a basis of information of a means which detects the thickness of a transfer form. CONSTITUTION:When the control signal of a controlling circuit 15 corresponds to a transfer paper thickness of 50g/m<2>, a changeover switch S is connected to a resistance Rb, and a pre-transfer exposure 10 performs the pre-transfer exposure with 30lux.sec; and when said control signal corresponds to a transfer form thickness of >=65g/m<2>, the switch S is connected to a resistance Ra, and the pre- transfer exposure lamp 10 performs the transfer exposure with 15lux.sec. Thus, transfer forms different in thickness are always transferred and separated stably even under a constant condition where the discharge current of a transfer electrode is 30muA. In this case, the transfer form thickness may be detected by the change of the electrostatic capacity between both poles of a capacitor.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a transfer electrostatic recording device equipped with a pre-transfer exposure lamp that exposes the surface of a photoreceptor after toner development and before transfer.

The pre-transfer exposure lamp increases the efficiency of transferring the toner image to the transfer paper by lowering the surface potential of the photoreceptor after toner development, and also increases the separation efficiency when separating the transfer paper from the photoreceptor using a separation electrode. It also affects. In conventional transfer electrostatic recording equipment companies equipped with such pre-transfer exposure lamps, the pre-transfer exposure lamp always irradiates the surface of the photoconductor with a constant amount of light, even if the thickness of the transfer paper varies. 9, in which the separation electrode separated the transfer paper with a constant discharge current. When the surface of the photoreceptor is irradiated with the pre-transfer exposure lamp in this manner, as shown in FIG. 1, there is a problem in that the photoreceptor undergoes optical fatigue and its service life is shortened. In Figure 1, a cold cathode fluorescent tube with a peak at about IIoo nm is used for the pre-transfer exposure rung.
When pre-transfer light attenuation is performed with a light intensity of θlux sec,
It shows the potential change on the surface of the photoreceptor after the original image is projected and before development in repeated transfers when no pre-transfer exposure is performed, and the transfer conditions other than the pre-transfer exposure are kept constant.

The present invention aims at minimizing fatigue of the photoreceptor due to pre-transfer exposure, and furthermore, in the case where the transfer paper is separated using a separation electrode, the transfer electrostatic method is capable of achieving stable and complete separation. An excerpt from a book designed to provide a recording device,
The present invention was arrived at as a result of investigating the influence of pre-transfer exposure on transfer and transfer paper separation.

The results in Tables 1 and 2 show the influence of pre-transfer exposure on transfer paper separation in a transfer electrostatic recording device in which transfer paper separation is performed using separation electrodes.

Table 7 shows the relationship between the surface potential of the photoreceptor after the original image is projected and before development and the difficulty of separating the transfer paper when the original is made into different types, such as a photo original and a text original, and the discharge current of the separating electrode. This is the case where no pre-transfer exposure was performed. In addition, Table 2 is
30 lu using the same pre-transfer exposure lamp as in K.
The results are shown in Table 9, where the pre-transfer exposure of x sea was carried out under the same conditions as in Table 1, except that the pre-transfer exposure was carried out and the range of change in the discharge current of the separation electrode was changed.

In addition, ○ and × in the table indicate that the separation of the transfer paper transferred to the Musen size with a weight and thickness of sat/m was stable and complete, and that the separation was not stably performed. The same Se--Te type as shown in FIG. 1 is used for the photoreceptor.

Table 1 Photoreceptor surface potential and separation characteristics Table 2 Separation characteristics during pre-transfer exposure This shows that pre-transfer exposure is not always necessary in order to be transferred.

Furthermore, as shown in Table 7, when the surface potential of the photoreceptor increases to ≦OOV, the separation characteristics of the transfer paper change significantly. The results shown in Figures 2 and 3 were investigated to find out why. .

V and V in FIGS. 2 and 3 are the surface potentials of the same transfer paper l immediately after passing through the separation electrodes as in Table 1, respectively, as shown in the reference figures. It can be seen that the surface potential v of the photoreceptor 3 is close to the surface potential of the photoreceptor 3 after Fi development. In the figure, i is a monophotonic substrate, and j is a transfer electrode. Figure 1 shows the photoreceptor surface potential in Table 1.
FIG. 3 shows the case where the photoreceptor surface potential is /0V. Comparing the results in Figures 2 and 3 with the □ results in Table 1, the surface potential of the transfer paper l after passing through the separation electrode 2 is approximately at the same level as the surface potential v2 of the photoreceptor below it. It can be seen that the separation of the transfer paper 1 is completed when the transfer paper 1 is removed. The charge on the surface of the photoreceptor is not very much removed by the discharge of the separation electrodes, and on the other hand, the charge on the transfer paper is rapidly removed when the potential is high, but when it becomes low, the left side of the photoreceptor surface is It is interpreted that the results shown in Table 1 are obtained because the static electricity is removed and the photoconductor surface potential does not have much influence on the static removal. Therefore, the static electricity removal does not affect the photoconductor surface potential after toner development. If the surface potential of the transfer paper is brought close to saturation, the separation electrode will stably separate the transfer paper, and the exposure by the pre-transfer exposure lamp will lower the surface potential of the photoreceptor after toner development. Just do it to lower it like that. However, as a practical matter, the problem is that the separation of the transfer paper becomes unstable due to a change in the original, rather than the problem that the separation of the transfer paper becomes unstable due to a change in the thickness and associated stiffness of the transfer paper. many.

Table 3 shows the ease of separating the transfer paper when the thickness of the transfer paper changes by changing the pre-transfer exposure amount. , the size of the transfer paper is AII, and the result of measuring the toner density on the surface of the light beam after toner development using a reflection density measuring means consisting of a combination of a light-emitting element and a light-receiving element is /, 3 (jllll
Conditions were set such that the front image front light body surface had a potential of about 3 ooVK''), the discharge current of the separation electrode 2 (see Fig. 4) was 130 μA, and the discharge current of the transfer electrode j was 30 μA, respectively.
It shows the number of sheets of transfer paper that can be separated without any problem when transferred to one sheet of transfer paper.

Table 3 Pre-transfer exposure amount and separation success rate From the results in Table 3, it can be seen that depending on the thickness of the transfer paper, the photoreceptor may be inferior to the pre-transfer exposure amount for separation.
It can be seen that the pre-transfer exposure can be omitted for slow tortoises such as 727 f/m''.

In addition, Section L1 shows the results of investigating the effect of pre-transfer exposure amount on transfer efficiency, that is, the ratio of the amount of transferred toner to the amount of developed toner, and shows that even with pre-transfer exposure of about 15 lux BeO, the transfer efficiency improves. It can be seen that it makes a significant contribution to

Reference Table: Pre-transfer exposure amount and transfer efficiency.
The same conditions as in Table 3 were used except for the conditions shown in this table.

The present invention has been made based on the above study results, and the transfer type electrostatic recording device of the present invention controls the amount of light irradiated from the pre-transfer exposure lamp to the photoconductor based on the information of the paper thickness detection means of the transfer paper. It is characterized by being configured to change.

The present invention will be explained below using examples shown in FIGS. 5 and 6.

FIG. 5 is a schematic configuration diagram showing an example of the recording apparatus of the present invention, and FIG. 6 is a circuit diagram for applying an alternating current voltage to a pre-transfer exposure lamp.

In the figure, ≦ is a charging electrode that charges the bare surface of the photoreceptor 3, 7 is the projection light of the original image, l is a toner developing device, 9 is a cleaner, 70 is III/a pre-transfer exposure lamp similar to that described in the figure, / / is a light-emitting element that emits light onto the transfer paper l', /2 is a light-receiving element that receives the light transmitted through the transfer paper l' tube of the light-emitting element l/ and converts it into an electrical signal, /J is the electricity of the light-receiving element /2 A detection circuit that outputs a thickness signal by compensating for differences in transmittance depending on paper mm from the signal, / is a control signal generation circuit that outputs a control signal from the thickness signal, and ls is a control signal generation circuit that outputs a control signal at an appropriate timing. A control circuit that outputs to the AC voltage application circuit 16, which is the AC voltage application circuit l shown in FIG.
In B, when the control signal of the control circuit/S is for the transfer paper thickness of 50 W/m2, the changeover switch S is connected to the resistor Rb@, and the pre-transfer exposure lamp IO is set to 3o lux sea. When the pre-transfer exposure of 15 lux se
This shows an example of applying pressure to expose the transfer of a! According to K, stable transfer paper separation can always be obtained for transfers of different thicknesses even if the discharge current of the separation electrode is set to a constant condition of /30 /JA s and the electric current of the transfer electrode is y μm. become. Since the pre-transfer exposure amount is reduced for thick transfer paper, it is possible to obtain the effect that the photoreceptor is less likely to be degraded by light even when the 301ux sea pre-transfer exposure is always carried out.

The present invention is not limited to the examples described above, and the thickness of the transfer paper may be detected by a change in capacitance when the transfer paper passes between the poles of a capacitor, or by the thickness and bending stiffness. Since this is relevant, stiffness may be used for songs that can be detected by a load cell or the like. Further, a fluorescent lamp other than an incandescent lamp or a cold-cave fluorescent tube may be used as the pre-transfer exposure lamp,
Control of the pre-transfer exposure amount is not limited to two steps, and instead of controlling the amount of light emission, a filter or the like may be replaced.

[Brief explanation of the drawing]

Figure 1 is a graph showing fatigue of the photoreceptor due to pre-transfer exposure.
FIGS. 2 and 3 are graphs showing the relationship between the photoconductor end surface potential and the separation of the transfer paper, and the reference is FIG. FIG. 3 is a partial side view of the transfer electrostatic recording device showing measurement positions, FIG. 5 is a schematic configuration diagram of the recording device of the present invention, and FIG. 6 is a circuit diagram showing an example of an AC voltage application circuit. l...transfer paper, c...separation electrode, 3...
・Photoreceptor, j...Transfer electrode, l...Toner developing device, 10...Pre-transfer exposure lamp, //...
Light emitting element, /J... Light receiving element, 13. Detection circuit,
/f...control signal generation circuit, lj...control circuit, 16...AC voltage application circuit, S...changeover switch. Patent applicant Konishiroku Photo Industry Co., Ltd. Tenko Hamamaki-5:

Claims (1)

[Claims] A transfer type electrostatic recording device equipped with a pre-transfer exposure lamp, characterized in that the irradiation light of the pre-transfer exposure lamp to the photoreceptor is changed based on information from a paper thickness detection means of the transfer paper. type electrostatic recording device.