JPS6168257A - Image recording apparatus - Google Patents

Abstract

PURPOSE:To make it possible to form a homogenous image by eliminating the non-uniformity of an electric field, by bending a recording head in matching relation to the surface shape of an image carrier and keeping the distance between a charged particle discharge opening part and the surface of the image carrier constant. CONSTITUTION:The whole of an ion generation and extraction apparatus A being a recording head is brought to a bent shape in matching relation to the radius of curvature of the cylindrical pheripheral surface of a dielectric drum B being an image carrier and supported by a support 8 having a bent surface in a state adhered by an adhesive 9. That is, because the dielectric drum B has a cylindrical shape, the bent surfaces of electrodes 1, 3, 5, dielectric layers 2, 4 and the support 8 constituting the ion generation and extraction apparatus A form concentric circular arc surfaces. At this time, the distance from each opening 6 of the electrode 5 to the drum B becomes equal with respect to all openings. The surface of the drum opposed to the perforated surface is parallel. Therefore, the electric fields in the intermediate region between the openings 6 and the drum B come to the same shape with respect to all of openings 6 and a homogenous image can be formed.

Description

[Detailed description of the invention] B. Purpose of the invention [Industrial application field] The present invention relates to an image forming apparatus.

More specifically, it has a large number of charged particle emitting apertures facing the image carrier surface, and selectively controls the emission of 6η7 particles from each of the apertures to cause the discharged charged particles to adhere to the image carrier surface. The present invention relates to an image recording apparatus equipped with an end for recording to form a charge pattern.

[Conventional technology]

The above-mentioned image recording method or apparatus is described in US Pat. No. 4,155,083 e.
No. 8 Specification, No. 8, etc., and it is possible to perform relatively high-speed recording processing.The recording head is small and the overall configuration of the apparatus is compact. Image compositing using multiple recording heads
It has advantages such as being able to use multiple colors.

The device disclosed in the above-mentioned US patent specification uses an ion generating and extracting device as a recording head, that is, ions are generated by electric discharge, and these are selectively extracted by a field according to an image signal. This method creates an electrostatic latent image by depositing it on a carrier. For convenience, this device will be specifically explained below as an example.

FIG. 5 is an explanatory diagram of the principle of ion generation and extraction of the ion generation and extraction device as a recording head. To the record F' A is
First electrode (drive electrode)1. Dielectric 2, second electrode (control electrode>3.: Ji dielectric, third electrode (screen electrode) 5 in this order, and second electrode 3, dielectric 4, third electrode 5. small-diameter ion-emitting apertures 6 are arranged and distributed densely along the length of the head A.The surface of the head A on which the ion-emitting apertures are formed is placed on the surface of the image carrier (solid dielectric) 8. Let them face each other.

C is a conductive substrate or a back electrode of the image carrier.

When an alternating voltage v1 such as an alternating current voltage is applied between the first and second electrodes 1 and 3, creeping discharge is induced on the dielectric surface 2a near the second electrode 3, and positive ions and negative ions are generated. and the second
By appropriately controlling the voltage v2 between the third electrodes 3 and 5 and the pressure v3 between the third electrode 5 and the back electrode C of the image carrier B, the generated positive ions and negative ions can be removed. One of the ions is emitted from the ion emitting aperture 6 toward the image carrier B and adheres to the surface of the image carrier B as an ion dot.

Therefore, when an image is created in which ion emission (positive or negative ion emission) is to be formed from the individual ion emission apertures that are densely arranged and distributed along the eldest of 1. The control circuit selectively performs main scanning control in accordance with the series pixel signals, and the head A and gl are controlled in a direction perpendicular to the main scanning direction.
l By relatively moving the image carrier in the sub-scanning direction (generally, the head A is fixed in place and the image carrier B is moved in the sub-scanning direction), the electrostatic image 7 of the target image is displayed on the surface of the image carrier 8 in a positive or negative manner. It is formed sequentially as a load pattern with Io/1 and 7 as Gakken. The formed latent image 7 is then developed with toner, and then the toner developed image is directly placed on the surface of the image carrier 8 (direct method), or the toner developed image is transferred to the surface of the transfer material. n (trans'I7:) person) to obtain a hard copy.

[Problem that the invention attempts to solve]

Incidentally, in order to reduce the number of elements in the driving electric circuit, the ion generating and extracting device which is the recording head A normally has the first electrode 1 and the second electrode 3 crossed in a matrix as shown in FIG. A method is adopted in which the discharge voltage for ion generation is sequentially applied to 1*1 of the first electrodes 1 at different times. For this reason, the third electrode 5 for extracting ions
The openings 6 are not arranged in a straight line, but are distributed with a width W over a certain range in the sub-scanning movement direction of the image carrier B, as shown in the figure. Therefore, when using a cylindrical image carrier, the distance between the opening 6 of the third electrode 5 and the surface of the image carrier 8 +! IQ
(Ion flying distance #) varies along the sub-scanning movement direction of the image carrier B. If the portion 7+5@W of the aperture 6 is sufficiently small compared to the radius r of the cylinder of the image carrier, this non-uniformity of the distance will hardly be a problem.

However, if W/r is increased by, for example, decreasing the radius r of the image carrier cylinder, the non-uniformity of the distance increases, which affects image formation. Experiments have shown that when -/r becomes a value of about 0.1 or more, the uniformity of the image is significantly disturbed. For this reason, the radius r of the cylinder of the image carrier cannot be made very small, making it difficult to downsize the device.

The invention aims to solve this problem.

Structure of the Invention: Means for Solving Problem C] The present invention has a large number of charged particle emitting openings facing the surface of an image carrier, and the charge '+h:particle emission from each of the openings is as follows. In an image recording apparatus equipped with a recording head that selectively controls the surface of the image carrier to form a charged pattern by adhering particles to the ejection cylinder '1, the surface portion of the image carrier that faces part F to the recording surface is curved. In the case of a curved shape, at least the surface of the recording head on the side where the charged particle emitting openings are formed is curved in accordance with the curved shape, and the surface of the recording head on the side where the charged particle emitting openings are formed and the curved surface of the image carrier are curved. The recording apertures were made to face each other at equal intervals, so that the distances between the charged particle emitting apertures of the recording holes H and D and the surface of the image carrier were approximately equal for all the apertures. The gist of the present invention is an image recording device characterized by the following features.

[For production]

By configuring as described above, the distances between the individual charged particle emitting openings of the recording head and the image carrier surface are equalized, so that uniform image formation is performed. Furthermore, since it is possible to reduce the radius of curvature of the image carrier, it is possible to reduce the size of the entire apparatus.

〔Example〕

FIG. 1 shows one embodiment. In this example, the entire ion generation and extraction device A, which is a recording head, is configured in a curved shape in accordance with the curvature of the cylindrical peripheral surface of a dielectric drum B, which is an image carrier. It is supported by being attached to a support 8 having a surface with an adhesive 9 or the like. lII, since the dielectric drum B has a cylindrical shape, Io/f? : The curved surfaces of the electrode layers 1, 3, 5, dielectric layers 2, 4, and support body 8, which constitute the raw extraction device A, are also arranged to form circular arc surfaces concentric with the drum B. At this time, the distance from the opening 6 of the third electrode 5 to the surface of the driver 48 or all the openings 6 becomes approximately equal. Further, the drum surface facing the opening surface is always kept parallel. Therefore, the electric field in the intermediate region between the M opening 6 and the drum B has the same shape for all openings 6, and uniform image formation can be expected. Electrostatic electricity W formed on the 8 surfaces of the dielectric drum! The image 7 is then developed with toner by a developing device (not shown), and the toner image is transferred to a transfer material and fixed, and a hard copy is output.

The second [Δ shows another embodiment. That is, the recording apparatus of this example moves toner 11 and recording paper B, which is an image carrier, along the surface of a 5-cylindrical toner transport body 10, and releases ions to the opposite side of the transport body 10 with the recording paper B in between. A layer of toner on the surface of the toner conveying body 10 is placed on the surface of the recording paper B opposite to the charged pattern forming side corresponding to the charged pattern 7 formed on the 8th surface of the recording paper by the ion generation and extraction device A. 11 is selectively attached to form an image. The ion generating apparatus A is constructed by curving the entire ion generating apparatus A so that the distance xi from the third electrode 15 to the recording paper B is constant according to !1.

C. As described in detail of the invention, the recording head A is curved to match the surface shape of the image carrier B, and the distance between the charged particle emission opening 6 and the surface of the image carrier 8 is kept constant. This makes it possible to eliminate non-uniformity of the electric field and form a homogeneous image.

As a result, the radius of curvature of the image carrier can be easily reduced, and the apparatus can be made smaller.

[Brief explanation of the drawing]

1 and 2 are enlarged cross-sectional views of the main parts of the first and second embodiments of the apparatus of the present invention, respectively, and FIG. 3 is a partially cutaway enlarged slope of the main part of the ion generation and extraction apparatus as a recording head. Figure, 4th
The figure is a cross-sectional model rA. Figure 5 is a diagram explaining the principle of ion generation and extraction. A is an ion generation and extraction device that serves as a recording head. B is the image carrier, l, 3, and 5 are the first, second, and third 'ils.
i pole, 2 and 4: A heel body, 6 is ion release opening.

Claims (2)

[Claims] (1) It has a large number of charged particle emitting openings facing the surface of the image carrier, and selectively controls the discharge of charged particles from each of these openings to form a charged pattern due to the adhesion of discharged charged particles on the surface of the image carrier. In an image recording apparatus equipped with a recording head for forming a charged particle, when the surface portion of the image carrier that the recording head faces has a curved shape, at least the surface of the recording head on the side where the charged particle emitting openings are formed is curved to match the curved shape. Then, the surface of the recording head on the charged particle emission aperture formation side and the curved surface of the image carrier face each other so that they are spaced at equal intervals, thereby making the distance between the charged particle emission aperture of the recording head and the surface of the image carrier smaller. An image recording device characterized in that all apertures are substantially equal. (2) The recording head is composed of three layers of electrodes separated from each other by an insulator, and the plurality of first electrodes in the top layer and the plurality of second electrodes in the middle layer are arranged so as to cross each other, and the intersection points By providing an opening in the insulator and the third electrode between the second electrode and the third electrode at the bottom layer, and applying a voltage between the first electrode and the second electrode, ions are generated near the second electrode. This is a patented ion generation/extraction device that generates ions, extracts them using an electric field between a second electrode and a third electrode, and between a third electrode and an image carrier, and deposits them on an image carrier to form a charged pattern. An image recording device according to claim (1).