JPH04371969A - image recording device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus used in copying machines, printers, etc.

0002

2. Description of the Related Art As described in, for example, US Pat. No. 3,689,935, the above-mentioned image recording apparatus uses an aperture electrode having a large number of openings (apertures) and a recording medium to charge the toner uniformly. A toner jet type image recording device has been proposed, which outputs an image by controlling an electric field and guiding a toner flow using a back electrode (counter electrode) disposed behind the device. In this image recording device, an aperture electrode is provided below the recording medium, a toner flow is guided toward the lower surface of the recording medium, and an image is formed on the lower surface of the recording medium. The recording medium on which the image has been formed in this way is transported to the rear heat fixing device where it is thermally fixed.
Output.

0003

[Problems to be Solved by the Invention] However, in conventional image recording apparatuses, an image forming means (also called a printing means) is provided at only one location, so when it is desired to print on both sides of a recording medium, First, the printing device prints on one side, and then the printed surface is thermally fixed by the thermal fixing device.Then, the recording medium is turned over and conveyed to the printing device again, printing is done on the recording medium, and the thermal fixation is repeated by the thermal fixing device. It needed to be done.

The double-sided printing method using such conventional devices has the following disadvantages. That is, (1) printing and heat fixing must be performed twice, which makes the operation cumbersome and takes twice as much time. (2) Since the second printing is performed on a heat-fixed recording medium, there is a risk that the image quality will deteriorate.

The present invention has been made to solve the above-mentioned problems, and its purpose is to form images on both sides of a recording medium much faster and with simpler operation than conventional devices. Moreover, it is an object of the present invention to provide an image recording device which has a compact structure, does not have a complicated structure, and has a small increase in manufacturing cost.

[0006]

[Means for Solving the Problem] In order to achieve this object, an image recording apparatus of the present invention includes an image forming means and a heat fixing means for fixing the image formed by the image forming means on a recording medium. In the image recording apparatus, a plurality of image forming means are arranged in front of the heat fixing means so as to face each other with respect to the transport path of the recording medium.

[0007]

[Operation] According to the image forming apparatus of the present invention having the above-mentioned configuration, after or simultaneously with forming an image on one side of the recording medium by at least one image forming means, the other side is formed by another image forming means. to form an image. After images are formed on both sides of the recording medium in this manner, the images formed on both sides of the recording medium are simultaneously thermally fixed by a common thermal fixing means. Therefore, the time required to form images on both sides is shortened to the same or slightly longer time than the conventional image formation time on one side.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to the drawings. In FIG. 1, an image recording device 19 is a toner jet type recording device, and its main parts include a recording section 1 and a heat fixing section 2. An insertion port 17 is provided on one side of the image recording device 19, and an ejection port 18 is provided on the other side.

[0009] An image is formed in the recording section 1 on a recording medium P such as plain paper that is inserted into the apparatus 19 through the insertion opening 17 and conveyed via a guide 15. Then, the image on the recording medium P is fixed in the thermal fixing section 2. Further, the recording medium P is transferred from the heat fixing section 2 to the guide 15.
is sent to the outlet 18 via the.

The recording section 1 includes two image forming means whose main parts are composed of a rotatable brush roller 3, an aperture electrode 9, and a counter electrode 12. These image forming means are arranged opposite to each other with the transport path of the recording medium P interposed therebetween.

Around each brush roller 3, a supply roller 4, a layer thickness regulating member 11, and a scraping member 10 are arranged in contact with the brush roller 3 in this order according to the rotating direction of the brush roller 3. It is provided. Further, each brush roller 3 is grounded. Each supply roller 4 is arranged inside a toner case K, and toner T is stored inside each toner case K.

An aperture electrode 9 is provided adjacent to the brush roller 3. Here, the aperture electrode 9 will be explained with reference to FIG. 2 as seen from the bottom side. The aperture electrode 9 includes a large number of apertures 5, an insulating layer 6,
It is composed of a reference electrode layer 7 and a large number of control electrode layers 8. The apertures 5 are opened in the insulating layer 6 at regular intervals and arranged in a line. Further, the reference electrode layer 7 is
The insulating layer 6 is provided on the brush roller 3 side (top side in the figure). Further, the control electrode layers 8 are provided independently around the aperture 5 on the lower surface of the insulating layer 6.

As shown in FIG. 1, the reference electrode layer 7 is connected to a negative (-) DC power source E1, and each control electrode layer 8 is connected to a corresponding signal source S.

Further, on the opposite side of the brush roller 3 with each aperture electrode 9 in between, a counter electrode 12 is provided with a certain space (gap) between the aperture electrode 9 and the aperture electrode 9 . Then, the recording medium P inserted through the insertion port 17 and sent via the guide 15 and the pair of auxiliary rollers 16 passes through this space.

The counter electrode 12 is connected to a negative (-) power source E.
Connected to 2. By applying this voltage, the toner T that has passed through the aperture 5 of the aperture electrode 9 is attracted to the recording medium P.

The heat fixing unit 2 is composed of a pair of heat rollers 13 containing a halogen lamp 21 as a heat source, and each heat roller 13 is nipped with a predetermined pressure to efficiently apply heat to the recording medium P. It is configured as follows.

The operation of the toner jet type image recording device 19 constructed as described above will now be described.

The recording medium P inserted through the insertion port 17 is
First, it is conveyed to the position of the aperture electrode 9 in front by the auxiliary roller 16 via the guide 15 . Below this aperture electrode 9, the toner T in the toner case K is
It is supplied to the brush roller 3 by the supply roller 4. At this time, the toner T comes into contact with the supply roller 4 and the brush roller 3, is rubbed, and is charged positively (+) in this embodiment. The toner T charged positively (+) in this way is carried by the brush roller 3. Then, the excess toner T supplied to the brush roller 3 is scraped off by the layer thickness regulating member 11. As a result, a uniform toner layer is formed on the brush roller roller 3.

[0019] In the vicinity of the aperture electrode 9,
The brush roller 3 is scratched by the scraping member 10. When the brush of the rotating brush roller 3 returns to its original position due to its elastic restoring force, an appropriate amount of toner T carried by the brush jumps up. As a result, the toner T is supplied to the aperture electrode 9 in the form of a cloud.

The cloud-shaped toner T charged positively (+) is attracted to the reference electrode layer 7 connected to the negative (-) power source E1. Then, the flow of the toner T is modulated by the voltage applied from the signal source S to the control electrode layer 8 of the aperture electrode 9 based on the image information, and the toner T is always stably transferred from the aperture electrode 9 to the recording medium P. Supplied. The toner flow is modulated by the aperture electrode 9 by the signal source S, and a toner latent image is recorded on the lower surface of the recording medium P. That is, the positively (+) charged toner T that has been modulated by the negative (-) power supply E2 connected to the counter electrode flies toward the counter electrode 12. This toner T is then attracted to the recording medium P conveyed by the auxiliary roller 16, forming an image (latent image).
is formed.

By the way, the image recording device 19 according to the above embodiment can selectively form an image on one side or both sides of the recording medium P. For example, when forming an image (printing) only on one side of the recording medium P, is printed only by the image forming means in front of the recording section 1, as described above. In addition, when performing image formation (printing) on both sides of the recording medium P, following the printing operation on one side, the rear image forming means of the recording section 1 performs image formation by the above-mentioned front image forming means. Printing is performed on the opposite side using a similar operation.

Thereafter, the recording medium P on which a toner latent image is formed on one or both sides is conveyed to the heat fixing section 2. In the thermal fixing section 2, the toner latent image on the recording medium P is pressed and heated by a pair of heat rollers 13, thereby being thermally fixed. Note that since this fixing method is a general method, detailed explanation will be omitted. Then, the recording medium P on which the image has been formed passes through the guide 15 to the ejection port 18.
taken from.

Note that the present invention is not limited to the embodiments described above, and can be modified without departing from the spirit thereof.

[0024]

As is clear from the above explanation, the image recording apparatus of the present invention has the following effects.

That is, an image can be formed not only on one side but also on both sides of a recording medium in one go without repeating operations. Moreover, the structural members other than the image forming means, such as the heat fixing means, are common to conventional apparatuses and there is no need to increase them, so the structure does not become too complicated or large. Furthermore, when forming images on both sides, it can be done at a speed that is almost the same as the image forming speed on one side using conventional devices, and the operation is stable.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of an image recording apparatus embodying the present invention.

FIG. 2 is a perspective view of an outline of an aperture electrode provided in the image recording device of FIG. 1, viewed from the side with some parts omitted;

[Explanation of symbols]

1 Recording department 2 Heat fixing section 5 Aperture 6 Insulating layer 7 Reference electrode layer 8 Control electrode layer 9 Aperture electrode 10 Scraping member 11 Layer thickness regulating member 12 Counter electrode 13 Heat roller T Toner P Recording medium K Toner case

Claims (1)

[Claims] 1. An image recording apparatus comprising an image forming means and a heat fixing means for fixing an image formed by the image forming means on a recording medium, wherein a plurality of image forming means are provided before the heat fixing means. An image recording apparatus characterized in that the image recording apparatuses are arranged opposite to each other with the conveyance path of the recording medium in the center.