JPS6223863B2 - - 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. The present invention relates to a recording device for forming. Recently, in this type of field, a recording method has been proposed in which format information such as hanging paper and printed information such as characters and symbols are formed on the same electrostatic latent image forming medium, and after simultaneous development, they are transferred to plain paper. , intensive research is being carried out toward practical application.

FIG. 1 shows a recording device already proposed by the present inventors.

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, and 8 is an optical A control circuit for controlling the fiber tube 7, 9 a developing device, 10 a developing bias source for applying a developing bias voltage to the developing device 9, 11 a transfer device 11, 12 normal recording paper, 13 a static eliminator, 14 1 is a static elimination 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 Figure 2.
The drum surface is charged to V ₀ potential, which is positive with respect to ground potential. Next, the light reflected from the lamp 3 by the original 4 is irradiated onto the photosensitive drum as a copy image. The surface potential state of the drum in this state is shown in FIG. As can be seen from the figure, the so-called hanging line area that is not irradiated with light still has a potential.
While V ₀ is maintained, the area irradiated with light decreases to approximately half the initial charging potential V ₀ , that is, to V ₀ /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 of the two light irradiations, the area A that is irradiated the first time but is not irradiated the second time, and the area B that is not irradiated the first time but is irradiated the second time have approximately half the initial charging potential, that is, approximately V ₀ / While being at two potentials,
The area irradiated with light twice becomes approximately at ground potential. The electrostatic latent image formed on the surface of the photosensitive drum 1 attracts negatively charged toner 9' by the developing device 9, and is transferred onto 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 residual toner adhering to the photosensitive drum 1 are static-eliminated from the surface thereof by a static eliminator 14 and a static eliminator 13. Afterwards, 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., please refer to the patent application filed in 1973.
See No. 99949.

However, the above method has the following drawbacks in terms of control. That is, in the above-mentioned method, when the initial charge potential V ₀ , the copying exposure amount, and the optical fiber tube exposure amount change, two positive electrostatic latent images, that is, the latent image a shown in FIG. , A changes in the potential level, which causes uneven print density after development.

This means that even if the voltage applied to the charger 2 is constant, it may not reach the specified surface potential due to age-related deterioration of the photoreceptor that makes up the photoreceptor drum, or the amount of light exposure from the lamp may be reduced, or the optical fiber may not reach the desired surface potential. This is caused by a decrease in the light intensity of the tube.

Therefore, an object of the present invention is to provide a recording apparatus that includes a plurality of charge latent image forming means, each of which forms a charge latent image using the residual potential portion of the preceding charge latent image forming means. The potential levels of the charge latent images formed by the charge latent image forming means can be made equal;
The object of the present invention is to realize a recording device that can obtain printing results without uneven printing density.

It is an object of the present invention to provide a charge supply means for applying charges to the surface of a charge latent image forming medium, and a plurality of charge latent images for forming a charge latent image corresponding to information to be printed by exposing the charge latent image forming medium. and a developing means for developing the obtained charge latent image, and each of the plurality of charge latent image forming means utilizes the residual potential portion after exposure by the preceding charge latent image forming means, and each of the plurality of charge latent image forming means A recording device that forms a latent charge image so that the potential level of the latent charge image formed by the charge latent image forming means is the same, and detects the amount of charge applied to the surface of the latent charge image forming medium by the charge supplying means. and a control means for controlling a drive unit of the charge supplying means so that an output signal from the detection means is returned to the charge supplying means so that the amount of charge supply is constant. , or detecting means for detecting the exposure amount of the charge latent image forming means or the amount of charge on the surface of the charge latent image forming medium after exposure by the charge latent image forming means, and an output signal from the detecting means as the charge latent image. A recording device comprising a control means for controlling a driving section of the charge latent image forming means so that the potential level is returned to the forming means to be equal to that of other charge latent images, or a recording apparatus using both of these in combination. This can be achieved by using a device.

The present invention will be explained below with reference to the drawings.

FIG. 3 shows an embodiment of a recording apparatus according to the present invention. In the figure, 1 is a photosensitive drum, 2 is a charger, 16 is a corona wire, and 17 is a corona wire 1
6 is a high voltage power supply for applying voltage, 18 is a control circuit, and 19 is a surface potential sensor placed downstream of the charger 2 in the vicinity of the photosensitive drum 1 to detect the surface potential of the surface of the photosensitive drum 1.

This example is an example for stably maintaining the initial charging potential. The charger 2 applies a high voltage of several KV to a corona wire 16 with a diameter of approximately 50 to 100 μm to ionize the air, and supplies the ions generated at this time onto the photosensitive drum 1 to charge the surface of the photosensitive drum 1. It is something. This method uses photosensitive drum 1
However, since corona discharge is inherently susceptible to the influence of the temperature and humidity of the air, potential fluctuations are likely to occur. Therefore, in this embodiment, the amount of charge on the surface of the photosensitive drum 1, that is, the surface potential, is detected by a surface potential sensor 19 installed after the charger 2 in a non-contact state with the photosensitive drum 1, and this detection result is It is fed back to the control circuit 18 that controls the voltage power supply 17. When the surface potential becomes higher than a predetermined voltage, the voltage applied to the corona wire 16 is lowered to reduce the amount of corona ions generated so that a predetermined charging potential can be obtained. On the other hand, when the charging potential becomes low, the voltage applied to the corona wire 16 is increased to obtain a predetermined charging potential.

FIG. 4 shows another embodiment of the recording apparatus according to the present invention. In the figure, 3 is a lamp made of a fluorescent lamp, 4 is a document, 19 is a drive circuit that drives the lamp 3, 20 is a control circuit that controls the drive circuit 19, and 2
1 is a photo sensor.

This embodiment is an embodiment applied to the first latent image forming step shown in FIG.
A drive circuit 19 that uses the output voltage to drive the lamp 3
The light is fed back to the control circuit 20 that controls the light so that a predetermined amount of light is obtained. The light intensity of lamp 3 is
Since it varies greatly depending on the temperature, the surface potential of the photosensitive drum after exposure tends to vary. Therefore, even if the lamp exposure varies from a predetermined exposure amount,
Immediately, the exposure amount of the lamp 3 is detected by the photo sensor 21, and the voltage of the lamp drive circuit 19 is corrected to reach a predetermined exposure amount.

FIG. 5 shows another embodiment of the recording apparatus according to the present invention. In the figure, 7 is an optical fiber tube, 22 is a drive circuit, 23 is a control circuit that controls the drive circuit 22, and 24 is a photo sensor.

This example is an example applied to the second latent image forming step shown in FIG. In this embodiment, similarly to the embodiment shown in FIG. 4, a photo sensor 24 is installed in front of the optical fiber tube 7, which is an exposure means for irradiating light onto the photosensitive drum 1, and the amount of exposure of the optical fiber tube 7 is determined by photo sensor 24. The output voltage is detected by the sensor 24 and fed back to the control circuit 23 to correct the drive voltage of the drive circuit 22. That is, when the exposure amount of the optical fiber tube 7 fluctuates from a predetermined exposure amount, the voltage applied to the cathode of the optical fiber tube 7 is corrected by the control signal of the control circuit 23 so that the exposure amount becomes the predetermined exposure amount.

FIG. 6 shows another embodiment of the recording apparatus according to the present invention. In the figure, 25 is the grid, 2
6 is a high voltage power supply, 27 is a control circuit, and the other numbers refer to the numbers of each embodiment described above.

This embodiment is a modification of the embodiment shown in FIG. 3, and similarly to the embodiment shown in FIG. The grid voltage is fed back to a control circuit 27 connected to a high voltage power supply 26 for driving the grid 25, which controls the grid voltage applied to the grid 25. That is, when the charging potential on the surface of the photosensitive drum 1 decreases, the grid voltage may be set high, and when the charging potential increases, the grid voltage may be set low.

As explained above, according to the present invention, it is possible to control the charging potential and the amount of exposure at the latent image forming section to be constant at all times, thereby realizing a recording device that can obtain good image quality without uneven print density. can do.

The present invention is very useful when applied to a copy printer that combines two types of electrostatic latent images on a photosensitive drum, as illustrated in FIG. That is, since the surface potentials of the electrostatic latent images formed by the respective electrostatic latent image forming means on the photosensitive drum can be precisely aligned, an image with uniform print density can be obtained. However, the present invention is not limited to this type of recording device; for example, the present inventors have already proposed a copying printer (Japanese Patent Application No. 48675/1982).
It can also be applied to obtain the same effect. this is
Although exposure by OFT is used as negative exposure and development is performed with magnetic toner, unevenness in print density occurs when the charging potential and exposure amount change. Therefore, good recording can be obtained by stabilizing the charging potential and exposure amount. Furthermore, the potential on the surface of the photosensitive drum after exposure by a latent image forming means such as a lamp or optical fiber tube is detected by a surface potential sensor as shown in FIG.
The exposure amount can also be stabilized by decreasing the exposure amount when the potential is lower than a predetermined potential, and increasing the exposure amount when the potential after exposure is high.

[Brief explanation of the drawing]

FIG. 1 is an apparatus configuration diagram of a recording apparatus to which the present invention is applied, FIG. 2 is a diagram of the recording principle of the recording apparatus shown in FIG. 1, and FIG. 3 is an embodiment of the recording apparatus according to the present invention. 4 to 6 show other embodiments of the recording apparatus according to the present invention. In the figure, 1 is a photosensitive drum, 2 is a charger, and 3 is a photosensitive drum.
is a lamp, 4 is a copy original, 7 is an optical fiber tube, 17 and 26 are high voltage power supplies, 18 and 2
0, 23, and 27 are control circuits, 19 is a surface potential sensor, 21, 24 are photo sensors, 22 is a drive circuit, and 25 is a grid.

Claims (1)

[Scope of Claims] 1. A charge supply means for applying a charge to the surface of a charge latent image forming medium, and two charge latents for forming a charge latent image corresponding to information to be printed by exposing the charge latent image forming medium. It includes an image forming means and a developing means for developing the obtained charge latent image, and after the surface of the charge latent image forming medium is charged to a predetermined potential by the charge supplying means, the charge latent image forming means is When the first charge latent image is formed by the latent image forming means, the residual potential of the exposed part is set to approximately 1/2 of the initial charge potential, and the second charge latent image is formed by the subsequent charge latent image forming means using the residual potential of the exposed part. and forms a charge latent image such that the residual potential of the portion exposed twice by the two charge latent image forming means becomes approximately 0, the charge latent image being formed by the charge supplying means. A detection means for detecting the amount of charge applied to the surface of the forming medium, and an output signal from the detection means is fed back to the charge supply means to control a drive section of the charge supply means so that the amount of charge supply is constant. 1. A recording device comprising a charging potential control means. 2. A charge supplying means for applying a charge to the surface of a charge latent image forming medium, two charge latent image forming means for exposing said charge latent image forming medium to form a charge latent image corresponding to the information to be printed; After the surface of the charge latent image forming medium is charged to a predetermined potential by the charge supplying means, the charge latent image forming means at the preceding stage of the two charge latent image forming means develops the latent charge image forming means. When forming one charge latent image, the residual potential of the exposed part is set to approximately 1/2 of the predetermined charge potential, and the second charge latent image is formed by the subsequent charge latent image forming means using the residual potential of the exposed part. A recording device that forms a charge latent image using two charge latent image forming means such that the residual potential of a portion exposed twice becomes approximately 0, the amount of exposure of the charge latent image forming means or the charge latent image formation being Exposure amount detection means or charge amount detection means for detecting the amount of charge on the surface of the charge latent image forming medium after exposure by the means, and an output signal from the exposure amount detection means or charge amount detection means to the charge latent image forming means. The residual potential of the portion of the surface of the charge latent image forming medium exposed once by the two charge latent image forming means is approximately 1/2 of the predetermined charged potential, and the residual potential of the portion exposed twice is approximately 1/2 of the predetermined charge potential. 1. A recording apparatus comprising: an exposure amount control means for controlling a driving section of the charge latent image forming means so that the charge latent image forming means becomes approximately zero.