JPH087516B2 - Image forming device - Google Patents

Abstract

PURPOSE:To improve the efficiency of image formation without making the size of a device large by developing an electrostatic latent image by toner, forming a main image by transferring the toner image on a recording paper and forming an auxiliary image by an auxiliary image forming mechanism disposed in a developing device. CONSTITUTION:The main image is formed on the recording paper 40 by using a photosensitive body by a main image forming mechanism 20. Simultaneously, the auxiliary image is formed on the paper 40 by the auxiliary image forming mechanism 30. The forming mechanism 30 is disposed in the developing device 23 which develops the main image by the toner. Besides, the toner in the developing device 23 is supplied on one of electrodes and passed through the toner passing hole 32 of a substrate 31 by an image information generation means. Then, the auxiliary image is formed on the photosensitive body 10 or the recording paper 40 where the main image is formed. Thus, the auxiliary image is formed on the recording paper together with the main image and the size of the device is prevented from being made large.

Description

The present invention relates to an auxiliary image such as a date or a mark on a recording paper on which a main image such as a copy image of a document or an image based on an image information signal is formed. The present invention relates to an image forming apparatus for forming an image.

(Prior Art) An image forming apparatus has been developed in which a recording paper on which a main image such as a copy image of a document or an image based on image information is formed is combined with an auxiliary image such as a date or a mark. Such an image forming apparatus usually forms a main image on a recording paper by a main image forming mechanism that adopts an electrophotographic process,
An auxiliary image such as a date or a mark is formed on the recording paper by an auxiliary image forming mechanism of a thermal transfer system. The auxiliary image forming mechanism is arranged on the downstream side of the fixing roller for fixing the main image formed by the main image forming mechanism on the recording paper in the recording paper conveyance direction, and usually includes a thermal transfer type printer head and an ink ribbon. have. After the main image is fixed on the recording paper, the auxiliary image is formed on the recording paper by the thermal transfer method by the auxiliary image forming mechanism.

(Problems to be Solved by the Invention) In such an image forming apparatus, an ink ribbon is necessary because the auxiliary image forming mechanism is a thermal transfer system. Moreover, since the printing speed is slow, it is necessary to reduce the conveying speed of the recording paper after passing through the fixing roller. Further, since it is arranged on the downstream side of the fixing roller in the recording paper conveyance direction, the distance from the fixing roller to the recording paper discharge port must be increased, which causes a problem that the apparatus becomes large.

The present invention solves such a problem, and an object thereof is to form an auxiliary image together with a main image on a recording sheet in a short time, and to prevent the apparatus from becoming large in size. To provide.

(Means for Solving the Problems) In the image forming apparatus of the present invention, an electrostatic latent image formed on a photoconductor based on image information is toner-developed by a developing device, and the toner image is transferred onto recording paper. An image forming apparatus having a main image forming mechanism for forming a main image on the recording sheet by doing so and an auxiliary image forming mechanism for forming an auxiliary image on the recording sheet, wherein the auxiliary image forming mechanism comprises: The substrate is provided in the developing device, has a plurality of toner passage holes, and has a substrate to which the toner in the developing device is supplied, and a through hole communicating with the toner passage hole of the substrate. A pair of electrodes provided in an insulating state with the substrate sandwiched so that the through holes are aligned with the respective toner passage holes, and at least an electric field for allowing the toner to pass through the toner passage holes according to image information. As it forms in the toner passage hole , Will be characterized by having an image information generation means to a predetermined potential between the pair of electrodes, the object can be achieved.

(Operation) In the image forming apparatus of the present invention, the main image forming mechanism using the photoconductor forms the main image on the recording paper, and the auxiliary image forming mechanism forms the auxiliary image on the recording paper. The auxiliary image forming mechanism is arranged in a developing device for developing the main image with toner, and the toner in the developing device is supplied onto one of the electrodes so that the image information generating means causes the toner passing hole of the substrate to pass through. An auxiliary image is formed on the photoconductor on which the main image is formed or on the recording paper.

(Example) The Example of this invention is described below.

FIG. 1 shows an image synthesizing apparatus according to the first embodiment of the present invention. The image synthesizing apparatus includes a well-known main image forming mechanism 20 having a body-grounded photosensitive drum 10, and an auxiliary image forming mechanism 30 arranged around the photosensitive drum 10. The main image forming mechanism 20 is provided to form a main image such as a copy image of a document or an image based on image forming information on the recording paper 40, and the auxiliary image forming mechanism 30 includes a date and a mark. It is provided to form such an auxiliary image on the recording paper 40.

The main image forming mechanism 20 uniformly charges the photosensitive drum 10 to, for example, a positive potential by the charger 21 that charges the photosensitive drum 10 rotating in the direction indicated by the arrow A. Then, the uniformly charged surface of the photosensitive drum 10 is exposed to light 22 from an optical system (not shown) to form an electrostatic latent image, and the developing device 23
The electrostatic latent image is developed with negatively charged toner supplied from The toner image on the photosensitive drum 10 is transferred by the transfer device 24 onto the recording paper 40 that is conveyed in the direction indicated by the arrow B. The recording paper 40 on which the toner image is transferred is conveyed to a fixing device (not shown), and the toner image is fixed on the recording paper by the fixing device. The photoconductor drum 10 to which the toner image has been transferred is removed by a cleaning device 25 arranged on the side of the photoconductor drum 10.

A developer in which toner and carrier are mixed is accommodated in the developing device 23, and an auxiliary image forming mechanism 30 for forming an auxiliary image such as a date or a mark is provided in the developing device 23. . The developing device 23 is a developing sleeve which is arranged so as to face the photoconductor drum 10 and is rotated in the direction indicated by an arrow D.
23e and a magnet 23 arranged in the developing sleeve 23e.
have a and. A toner supply roller 38 in the auxiliary image forming mechanism 30 is arranged below the developing sleeve 23e. An agitating paddle 23b is arranged on the side of the auxiliary image forming mechanism 30 opposite to the photosensitive drum 10.
A toner hopper 23d containing toner is disposed above the stirring paddle 23b. The toner supplied from the toner hopper 23d is stirred with the developer by the stirring paddle 23b, and the developer is developed into the developing sleeve 23e. Is supplied to. Then, by the rotation of the developing sleeve 23e, the developing sleeve 2
The developer is conveyed on the peripheral surface of 3e. The developer conveyed along the peripheral surface of the developing sleeve 23e is regulated to a predetermined amount by the regulating member 23f above the developing sleeve 23e, and is conveyed to a portion facing the photoconductor drum 10. The surplus developer is returned to the stirring paddle 23b by the partition plate 23c.

A toner supply roller 38 of the auxiliary image forming mechanism 30 is arranged below the developing sleeve 23e. The auxiliary image forming mechanism 30, as shown in FIG.
And an insulating substrate 31 arranged between the photosensitive drum 10 and the photosensitive drum 10. The insulating substrate 31 has a large number of toner passage holes.
32 are arranged side by side in the axial direction of the photosensitive drum 10, and a mesh-shaped common electrode 33 made of a conductive member is laminated on the surface of the insulating substrate 31 on the toner supply roller 38 side. There is. Each mesh of the common electrode 33 is in a state in which only the toner in the developer passes and the carrier does not pass. A predetermined negative voltage is applied to the common electrode 33 by a bias power source 34b.

Further, on the surface of the insulating substrate 31 on the photoconductor drum 10 side, a large number of signal electrodes 35 each having a through hole 35a similar to the toner passing hole 32 are attached corresponding to each toner passing hole 32. . Each signal electrode 35 surrounds each toner passage hole 32 of the insulating substrate 31, and the signal electrode 35 and the toner passage hole 32 are aligned with each other.
The signal electrodes 35 provided in the adjacent toner passage holes 32 are not in contact with each other. Each signal electrode 35
, A predetermined voltage is applied by the image information generating element 34a based on the image information.

The toner in the developing device 23 is supplied to the mesh-shaped common electrode 33 on the insulating substrate 31 by the toner supply roller 38 arranged in the developing device 23.

The image information generating element 34a, to which a predetermined negative voltage is applied to each signal electrode 35 in accordance with the image information, has a lower potential than the common electrode 33 to form image information when it is not necessary to form image information. If so, a higher potential than the common electrode is applied.

Below the developing device 23 is a recording paper conveyance path along which the recording paper 40 is conveyed in a direction indicated by an arrow B in FIG. 1, and below the photosensitive drum 10, the recording paper conveyance path is conveyed. A transfer device 24 for transferring an image onto the recording paper is provided. The recording paper 40 on which the toner image is transferred is conveyed to a fixing device (not shown), and the toner image is fixed on the recording paper by the fixing device. The cleaning device 25 removes the toner and the like remaining on the surface of the photosensitive drum 10 onto which the toner image has been transferred.

The operation of such an image forming apparatus will be described. In this image forming apparatus, the charger 21 charges the surface of the photoconductor drum 10 to a positive potential. The surface of the photosensitive drum 10 is
Light 22 from an optical system (not shown) is exposed. On the exposed surface of the photoconductor drum 10, the charge disappears, so that an electrostatic latent image corresponding to the main image is formed on the photoconductor drum 10 by the positive charge. The electrostatic latent image formed on the photoconductor drum 10 is developed by the toner supplied from the developing device 23, and a toner image corresponding to the main image information is formed on the photoconductor drum 10.

When the toner image corresponding to the main image information is thus formed on the surface of the photoconductor drum 10, the auxiliary image forming mechanism 30 provided in the developing device 23 is formed on the surface of the photoconductor drum 10. Auxiliary images such as dates and marks are formed. A photosensitive drum is formed on the insulating substrate 31 of the auxiliary image forming mechanism 30.
When the charged portion on the surface of which the auxiliary image is to be formed is opposed, the image information generating element 34a causes the predetermined signal electrode 35
On the other hand, a higher potential than the negative potential applied to the common electrode 33 is applied. As a result, an electric field for passing the negatively charged toner is formed in the predetermined toner passage hole 32 of the insulating substrate 31, and the negatively charged toner supplied by the toner supply roller 38 in the developing device 23 is transferred to the common electrode 33. Through the mesh and a predetermined toner passage hole 32. And the photoconductor drum
The toner that has passed through the toner passage hole 32 is attached to the positively charged surface of 10. Since the image information generating element 34a applies a lower potential than the common electrode 33 to the signal electrode 35 that does not need to form an image, the toner charge hole 32 corresponding to the signal electrode 35 is negatively charged. No electric field is formed through the toner.

In this way, the potentials of a large number of signal electrodes 35 are controlled based on the image information generating element 34a, and on the surface of the photosensitive drum 10, a toner image corresponding to the main image information and a toner corresponding to the auxiliary image are formed. An image is formed.

The toner images corresponding to the main image and the auxiliary image are transferred onto the recording paper 40 by the transfer device 24. The recording paper 40 to which the main image and the auxiliary image are transferred is conveyed to a fixing device (not shown), and the respective images are fixed on the recording paper 40 by the fixing device. The toner and the like remaining on the photosensitive drum 10 onto which the toner image has been transferred are removed by the cleaning device 25.

FIG. 3 shows a second embodiment of the image forming apparatus of the present invention. In this image forming apparatus, an insulating substrate 31 provided with a large number of toner passage holes 32 in the auxiliary image forming mechanism 30.
Is disposed below the developing device 23 so as to face the recording paper conveyance path. The toner passage holes 32 of the insulating substrate 31 are arranged in a direction orthogonal to the recording paper conveyance direction.
A toner supply roller 38 for supplying the toner in the developing device 23 to the insulating substrate 31 is arranged above the insulating substrate 31.

As shown in FIG. 4, a mesh-shaped common substrate 33 is provided on the surface of the insulating substrate 31 facing the recording paper 40, and the other surface is aligned with each toner passage hole 32. Many signal electrodes 3 each having a through hole 35a
5 are arranged. The common electrode 33 has a bias power supply 34b.
Due to this, a predetermined negative potential is applied. Further, each signal electrode 35 has an image information generating element 34a based on the image information.
Due to this, a predetermined negative potential is applied.

Below the signal electrode 35 of the insulating substrate 31, a base roller 50 as a counter electrode is arranged. The base roller 50 is grounded. The recording paper 40 is conveyed between the signal electrode 35 and the base roller 50 in contact with the base roller 50.

In this embodiment, the auxiliary image forming mechanism 30 provided in the developing device 23 allows the toner to pass through the predetermined toner passage holes 32 on the recording paper 40 before the main image is transferred. The toner that has passed through the toner passage hole 32 is recorded on the recording paper 40 by the electric field between the grounded base roller 50 and the signal electrode 35.
Dropped on.

In this way, the main image formed on the photoconductor drum 10 is transferred onto the recording paper 40 on which the auxiliary image is formed by the transfer device 24.
And the auxiliary image is formed on the recording paper 40 together with the main image. Both of these toner images are fixed by a fixing device (not shown).

Furthermore, FIG. 5 shows a third embodiment of the image forming apparatus of the present invention. In the image forming apparatus of this embodiment, the toner hopper is
23d is disposed on the side of the developing device 23 opposite to the side where the photosensitive drum 10 is disposed, and the auxiliary image forming mechanism 30 is disposed below the toner hopper 23d. Auxiliary image development mechanism 30
The insulating substrate 31 of is at the bottom of the toner hopper 23d,
A toner supply roller 38 is arranged horizontally so as to face the recording paper conveyance path, and a toner supply roller 38 is arranged above the insulating substrate 31. A base roller 50 is arranged below the insulating substrate 31. The toner in the toner hopper 23e is stored in the chamber in which the developing sleeve 23e is housed, and the toner replenishing roller 23 is disposed above the toner supplying roller 38.
supplied by g.

The other structure of the auxiliary image forming mechanism 30 is the same as that of the auxiliary image forming mechanism of the image forming apparatus of the second embodiment, and therefore its explanation is omitted.

A conveyor belt 60 that conveys the recording paper 40 on which the auxiliary image is formed is disposed between the base roller 50 and the transfer device 24.

Also in this embodiment, the recording paper before the main image is transferred
An auxiliary image is formed on 40.

In the present embodiment, since the insulating substrate 31 is formed in the toner hopper 23d that stores the replenishing toner, the toner is efficiently supplied to the toner passage hole 32 of the insulating substrate 31.

(Effects of the Invention) In the image forming apparatus of the present invention, the electrostatic latent image formed on the photoconductor is thus toner-developed by the developing device, and the toner image is transferred to the recording paper. An image is formed, and auxiliary images such as marks and dates are formed by an auxiliary image forming mechanism arranged in the developing device. Therefore, it is not necessary to dispose a hopper for supplying toner for forming an auxiliary image, and there is no fear that the apparatus becomes large.
Further, since the main image and the auxiliary image are fixed at the same time,
The efficiency of image formation is significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of an image forming apparatus of the present invention, FIG. 2 is an enlarged view of a main part of an auxiliary image forming mechanism in the image forming apparatus, and FIG. 3 is a second diagram of the image forming apparatus of the present invention. FIG. 4 is a schematic configuration diagram showing an embodiment, FIG. 4 is an enlarged view of a main part of the auxiliary image forming mechanism, and FIG. 5 is a schematic configuration diagram showing a third embodiment of the image forming apparatus of the present invention. 10 ... Photosensitive drum, 20 ... Main image forming mechanism, 23 ... Developing device, 30 ... Auxiliary image forming mechanism, 31 ... Insulating substrate, 32
...... Toner passage hole, 33 ...... Common electrode, 34 …… Bias circuit, 35 …… Signal electrode, 40 …… Recording paper.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03G 15/05 G03G 15/00 115

Claims (1)

[Claims] 1. A main image is formed on a recording paper by developing an electrostatic latent image formed on a photoconductor on the basis of image information with a toner by a developing device and transferring the toner image onto the recording paper. An image forming apparatus having a main image forming mechanism and an auxiliary image forming mechanism for forming an auxiliary image on the recording paper, wherein the auxiliary image forming mechanism is arranged in the developing device. And a through-hole communicating with the toner passing hole of the substrate, and each through hole is aligned with each toner passing hole. A pair of electrodes provided in an insulating state with the substrate sandwiched therebetween, and the pair of electrodes so as to form an electric field at least in the toner passage hole so that the toner passes through the toner passage hole in accordance with image information. Image information with a certain potential between the electrodes An image forming apparatus comprising: a report generating unit.