JPS6051108B2 - recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording device using an electrophotographic method or an electrostatic recording method, and more specifically, the present invention relates to a recording device using an electrophotographic method or an electrostatic recording method. The present invention relates to a recording device that forms images.

Recently, in this type of field, a recording method has been proposed in which format information such as hangings and printed information such as letters and symbols are formed on the same electrostatic latent image forming medium, developed simultaneously, and then transferred to plain paper, and this method has been put into practical use. Efforts are being made to develop this technology. Rail, Mami LnF) De + Δ Mouth 11 fists ``Kyoan 17'' Suya Hime Oki.

In the figure, 1 is an electrostatic latent image forming medium (hereinafter simply referred to as a photosensitive drum), 2 is a charger, 3 is a lamp, 4 is a copy original, 5 and 6 are optical mirrors, 7 is an optical fiber tube,
8 is a control circuit for controlling the optical fiber tube 7; 9;
1 is a developing device, 10 is a developing bias source for applying a developing bias voltage to the developing device 9, 11 is a transfer device, 12 is ordinary recording paper, 13 is a static eliminator, 14 is a static eliminating lamp, and 15 is a cleaner.

The principle of operation will be explained with reference to FIG.

First, the surface of the photosensitive drum 1 is positively charged by the charger 2. This state is shown in FIG. 2, where V is of positive polarity with respect to ground potential. The drum surface is charged to a potential. Next, the light reflected from the lamp 3 by the original 4 is irradiated onto the surface of the photosensitive drum as a copy image. The surface potential state of the drum in this state is shown in FIG. As shown in the figure, the so-called hanging line area that is not irradiated with light still holds the potential °Vo, while the area that is irradiated with light is at the initial charging potential V. approximately half of V. /2 potential. Next, the optical fiber tube 7 irradiates the photosensitive drum 1 with light to obtain a combined electrostatic latent image on the photosensitive drum 1.

This state is shown in FIG. 2. As a result, when the light is irradiated twice in total, the area A that is irradiated the first time but not the second time and the area B that is not irradiated the first time but is irradiated the second time are approximately half of the initial charging potential, that is, approximately V . /2 potential, while the area irradiated twice with light becomes approximately ground potential. The electrostatic latent image formed on the surface of the photosensitive drum 1 is transferred to a developing device 9.
The negatively charged toner 9'' is attracted and transferred to the recording paper 12 by the transfer device 11.

The toner adhering to the recording paper 12 is fixed by a fixing device (not shown), while the photosensitive drum 1 and the photosensitive drum 1
After the residual toner adhering to the surface of the photosensitive drum is neutralized by a static eliminator 14 and a static eliminator 13, the residual toner adhering to the surface of the photosensitive drum is mechanically scraped off by a cleaner 15. The above is a series of printing steps, and the above steps are repeated.

For other detailed operations, etc., see, for example, Japanese Patent Application No. 53-9.
Please refer to 994tan.

However, the above method has the following drawbacks in terms of control.

That is, in the above method, when the initial charging potential VOl, the copying exposure amount, and the optical fiber tube exposure amount change, two negative electrostatic latent images, that is, the latent image B and I in FIG. This is because the potential level shown by changes, and uneven print density occurs after development.

This means that even if the voltage applied to the charger 2 is constant, the surface of the photosensitive drum actually deteriorates due to age-related deterioration of the photosensitive member that makes up the photosensitive drum. This is caused by the surface not reaching a predetermined surface potential, the exposure amount of the lamp being reduced, or the light intensity of the optical fiber tube being reduced. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a recording apparatus having a plurality of electrostatic latent image forming means, capable of always stably and equally controlling the potential level of the latent image formed by each electrostatic latent image forming means. Therefore, it is an object of the present invention to realize a recording device with uniform print density. An object of the present invention is to provide a recording apparatus in which a composite image is formed on an electrostatic latent image forming medium by a plurality of electrostatic latent image forming means, in which a composite image is formed on an electrostatic latent image forming medium by a first electrostatic latent image forming means. a detection means for detecting the potential level of an electrostatic latent image formed thereon; and a detection means for forming an electrostatic latent image on a second or subsequent electrostatic latent image forming means based on an output signal from the detection means. This can be achieved by providing a recording apparatus comprising a control means for controlling an input signal.

The present invention will be explained below using the drawings. FIG. 3 shows an embodiment of the recording apparatus according to the present invention.

In the figure, 16 is a surface potential sensor that detects the surface potential of the photosensitive drum, 17 and 18 are a lamp drive circuit and an optical fiber tube drive circuit, respectively, although omitted in the explanation of FIG. 1, and 19 is a surface potential sensor 16. This is the lowest potential hold circuit connected to.

All other numbers in the figure refer to those in FIG. 1.
In the present invention, as shown in the drawings, the photosensitive drum surface between the first electrostatic latent image forming means, that is, the copying exposure means, and the second electrostatic latent image forming means, that is, the optical fiber tube exposing means. A surface potential sensor 16 for measuring the surface potential after the first exposure by the first electrostatic latent image forming means on the surface of the photosensitive drum is disposed adjacent to the second electrostatic latent image forming means. This is input to the drive section of the electro-latent image forming means.

That is, to describe the embodiment, the surface potential of the photosensitive drum 1 after copying exposure by the lamp 3 is measured by the surface potential sensor 1.
Detected by 6.

Of course, at this time, the potential state of the photosensitive drum 1 after copy exposure is V as shown in FIG. /2 and unexposed and therefore still at the initial charging potential V.
coexist with areas that maintain However, since the value required in the present invention is (VO-VO/2), only the surface potential VO/2 of the exposed area needs to be detected here. Therefore, in this embodiment, a lowest potential hold circuit 19 is connected to the surface potential sensor 16 to maintain a voltage of V. /2 is detected.
Now, the detection output obtained via the lowest potential hold circuit 19 is input to the optical fiber tube drive circuit 18.

In the optical fiber tube drive circuit 18, the surface potential V of the photosensitive drum is sent from the lowest potential hold circuit 19.
. /2, a drive voltage corresponding to the value of (■o - ■o/2) is applied to the optical fiber tube 7 via the control circuit 8. As a result, as shown in Fig. 2, 2
The surface potentials in the two positive latent image areas A and B are equal to each other, and therefore, after development, an excellent image without uneven development density can be obtained. As described above, according to the present invention, changes in the exposure amount of the first latent image forming means such as aging deterioration of the photosensitive drum, fluctuations in initial charging potential, and aging decrease in lamp exposure amount can always be followed. Since the exposure amount of the second electrostatic latent image forming means is determined by the method, it is possible to eliminate variations in the latent image potential due to variations in the exposure amount of each exposure means when a composite image is obtained using a plurality of exposure means. can. Although the above-mentioned embodiment uses two types of exposure means, the present invention is not limited to this.
It is also applicable to a recording apparatus having three or more types of exposure means.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conceptual diagram of a conventional recording apparatus, FIG. 2 is a diagram for explaining the latent image forming process of the recording apparatus shown in FIG. 1, and FIG. 3 is an illustration of a recording apparatus according to the present invention. This is an example.

Claims (1)

[Claims] 1. In a recording device in which a composite image is formed on an electrostatic latent image forming medium by a plurality of electrostatic latent image forming means, an illuminance that reduces the electric potential of the initially charged bright area on the electrostatic latent image forming medium by approximately half. a detection means for detecting a potential level of an exposed area of an electrostatic latent image formed on the electrostatic latent image forming medium by a first electrostatic latent image forming means for exposing a positive image; A second step that exposes a positive image at an illuminance that reduces the potential of the exposed bright portion of the first latent image forming means to approximately zero based on the output signal.
Alternatively, a recording apparatus comprising a control means for controlling an input signal for forming an electrostatic latent image to a subsequent electrostatic latent image forming means.