JPS5858565A - Picture recorder - Google Patents

Abstract

PURPOSE:To reduce the size and cost of a titled device by disposing nozzle heads which inject ink liquid dissolved therein with colored dyes or colored liquid toners near the outer side of a photosensitive drum in roughly parallel with the tangent of the drum. CONSTITUTION:Three pieces of nozzle heads 6Y, 6M, 6C move back and forth in one body in the scanning direction of a photosensitive drum 5 along a guide 7. The outside circumferential surfaces of nozzles 20 are enclosed of electrostrictive elements 21, and when high frequency voltages are applied to the elements by a driving circuit 22, ink liquid is injected in the form of particles or as jet flow. While the jet flow passes through charging electrodes 23, said flow is charged to the polarity reversed from that of the electrostatic latent images on the drum 5 and therefore the ink liquid is stuck thereon according to the potential intensities of the electrostatic latent images. In this case, colored pictures are obtained on one piece of the drum 5 by applying the high frequency voltages to the electrostrictive elements 21 for a time of one turn at a ratio of one time in 3 turns of the drum 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color image recording apparatus, and more particularly to an image recording apparatus that performs color printing of an electrostatic latent image created by electrophotography using a simple wet method.

In general, devices for recording color images using electrophotography, particularly color image recording devices used as output terminals for computers, are capable of copying ordinary monochrome electrophotography, as shown in Japanese Patent Application Laid-open No. 511-11-680. There is a method in which the machine has developing units for three colors or a reference color, and the developing units for each color are switched and used. However, since the photosensitive drum installed in each developing device is quite long, the size of the developing device itself becomes large.
Therefore, a color image recording apparatus that requires a plurality of these developing units has the disadvantage that the entire apparatus becomes large in size.

An object of the present invention is to eliminate such drawbacks and provide a compact and low-cost image recording device.

To avoid this, in the present invention, an ink liquid containing colored dye or a solution containing colored toner dissolved in a solvent is ejected from a nozzle to develop an electrostatic latent image formed on one photosensitive drum. and develop it.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 shows an optical system in an embodiment of the image recording apparatus of the present invention.
Here, l is a semiconductor laser, c is a collimator lens, and 3
4 is a rotating polygon mirror, 4C is an imaging lens, and j is a photosensitive drum, which rotates in the direction of the arrow.

The modulated light beam emitted from the semiconductor laser 1 is made into parallel light beams by a collimator/lenscoder, and enters a rotating polygon mirror 3 where it is optically deflected. The deflected light beam focuses an image spot on the photosensitive drum S by an imaging lens. One-dimensional optical scanning is performed by the rotating polygon mirror 3, and a two-dimensional light intensity distribution is formed on the photosensitive drum j by rotation of the photosensitive drum S. 6Y, 6M.

6C is Y (yellow), M (magenta), C (
This is a nozzle head that ejects an ink liquid containing a colored dye (cyan) dissolved therein.These three solid nozzle heads work together as a unit and move along the nozzle head guide 7 to the photosensitive drum! It reciprocates in the scanning direction (generating direction).

FIG. 2 shows an example of the image recording apparatus of the present invention including the optical system shown in FIG. Exposure device 10, nozzle head 06 as a current exposure device
(Heads 6Y, 6M, and 60 shown in the first diagram are collectively designated by the reference numeral 6), transfer charger/J, cleaning section 13
Arrange them sequentially.

In addition, l# is a transfer drum, /J is a cassette loaded with transfer paper /4, and the transfer paper 14 in the cassette 1j is fed out while being wound around the transfer drum l# via a roller 17, and is sent out onto the photosensitive drum j. Transfer the rowing information to transfer paper/6. Furthermore, /I is a gutter and collects excess ink liquid. - DC corona discharge is applied to the surface of the photosensitive drum j from the next charger 111C, and the photosensitive member on the surface of the photosensitive drum j is uniformly charged positively or negatively. In the exposure and simultaneous charging section, -
By applying a direct current corona discharge or an alternating current corona discharge with a polarity opposite to that of the next charging to the photoconductor, and at the same time exposing the photoconductor drum j to a light beam scanned by a rotating polygon mirror J, electrostatic latent is generated on the photoconductor drum j. Form an image.

Next, by uniformly irradiating the electrostatic latent image on the photoreceptor with light using a full-surface exposure device 10 such as a fluorescent lamp, the difference in surface potential between areas hit by the recording light beam and areas not hit can be increased. to produce a high-contrast electrostatic latent image on the surface of the photosensitive drum j. The development is carried out using the nozzle head 6Y (t* halo M) shown in the first figure.

This is done by ejecting ink liquid from the nozzle 60). These nozzle heads 6Y, 6M, and 60 each have Y(
Ink liquids colored in K (yellow), M (magenta), and C (cyan) are stored, and one color is used for each rotation of the photosensitive drum j. The aforementioned high-contrast electrostatic latent image generated on the surface of the photosensitive drum S is developed into a positive image when the ink liquid has the opposite polarity to the latent image charge, and when the ink liquid has the same polarity as the latent image charge. In some cases, it is manifested in a negative way.

The image thus produced is transferred by a transfer charger 12 onto a transfer paper /4 wound around a transfer drum /l.

The excess ink used for development is collected using a gutter/liter. The cleaning unit 13 wipes off the remaining ink liquid remaining on the photosensitive drum S after the photosensitive drum j completes image transfer.

Details of the above-mentioned nozzle head 6 are shown in FIG.

The outer peripheral surface of the nozzle at the tip of the nozzle head containing the ink liquid is surrounded by an electrostrictive element I, and the electrostrictive element I is
By applying a high frequency voltage to the nozzle, the ink liquid is ejected from the nozzle in the form of particles or as a jet stream. The ejected ink liquid is charged to a polarity opposite to that of the electrostatic latent image formed on the photosensitive drum S while passing through the charge band V and charger. The ink liquid that has passed through the charged electrode n is transferred to the photosensitive drum S.
It receives electrostatic attraction due to the electrostatic force above. This attractive force is proportional to the surface potential. Therefore, the ink droplets are deposited on the photosensitive drum S in accordance with the potential strength of the electrostatic latent image. The nozzle head 6 is scanned in one direction across the photosensitive drum j, and the high frequency voltage applied to the electrostrictive element l is applied to the photosensitive drum j.
For example, when three nozzle heads 6Y, 6M, and 60 are used, a constant frequency is constantly applied from the drive circuit n over the period of one rotation at a rate of once every three nozzle heads. The ink liquid is ejected during that time.

During the above-mentioned operation, as shown in the figure, the nozzle head 6 is arranged near the outer side substantially parallel to the tangential direction of the photosensitive drum S, and the nozzle head 6 is placed between the straight direction of the ink liquid ejected from the nozzle head 6 and the photosensitive drum S. Since the predetermined gap d is provided, it is possible to avoid the inconvenience of the ink liquid directly colliding with the photosensitive drum j, resulting in excessive supply of the ink liquid or a double effect. As a result, the excessive amount of ink used for development can be completely removed by the cleaning section 13, producing extremely clear reproduced images.
can be achieved.

Further, in particular, in the present invention, since development is performed by reciprocating movement of the nozzle head B, the size of the apparatus can be extremely small in the case of color printing. In the case of color printing, all you have to do is move the nozzle heads ay, eM, 60 for each color of Y, M, and O at the same time using the same guide 7. Only one is required, which simplifies the configuration.

Furthermore, the nozzle head in the present invention is not intended for recording high-density information as in the case of inkjet recording, but it is sufficient to spray developing ink or liquid toner roughly. High precision machining is not required for the head. Further, satellites may occur in images recorded with ink liquid and ejected liquid toner. Therefore, the frequency of the voltage applied from the drive circuit n may be set to a high frequency, thereby enabling high-speed injection and deflection. In order to increase the recording speed, it is necessary to speed up the reciprocating motion of the nozzle head.
This can be avoided by increasing the deflection angle of the ink liquid or jetted liquid toner. The reason for this is that a plurality of scanning lines written by the light beam (for example, SO-1.0 lines) can be developed with one head movement. Also, in order to achieve higher speed,
Two or more nozzles may be provided on the same head to expand the current width that can be covered by one movement of the head.

As is clear from the above description, according to the image recording apparatus of the present invention, ink liquid or liquid toner is ejected from the nozzle head to one photosensitive drum, and an electrostatic latent image on the photosensitive drum is made visible. Therefore, when multiple colors of ink liquid or liquid toner are required, such as for color images, multiple nozzle heads are arranged on a single photosensitive drum according to the multiple colors. Color images can be developed by reciprocating the drum in the generatrix direction and allocating one rotation of the photosensitive drum to each nozzle head in time sequence. There is no need to provide Therefore, the present invention has a very significant effect in producing a small, low-cost color printer.

Although the image recording apparatus of the present invention has been described above for use in color development, the present invention is of course not limited to this and can be effectively applied to image recording apparatuses for monochrome development.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an optical system of an embodiment of the image recording device of the present invention, FIG. 2 is a side view showing the configuration of an embodiment of the image recording device of the present invention, and FIG. 3 is a detail of the nozzle head thereof. It is a line diagram showing an example of composition. / -... Semiconductor laser, Co... Collimator...
Lens, 3... Rotating polygon mirror, Da... Imaging lens, j... Photosensitive drum, e, eY, 6M, 6
0... Nozzle head, 7... Nozzle head guide Sr...-
Next charger, 9... Exposure simultaneous charger, 10-Full surface exposure device, tλ...Transfer charger, 13...Cleaner/
Transfer drum, /3 cassette, /1
...transfer paper, 17...roller, /l...rattle,
I... Nozzle... Electrostrictive element,
n...drive circuit. Patent applicant Canon Co., Ltd. Figure 1 Figure 3

Claims (1)

[Scope of Claims] 1) One photosensitive drum for recording an image as an electrostatic latent image, and an ink liquid containing a colored pigment dissolved therein or liquid colored toner is ejected and sprayed onto the electrostatic latent image on the photosensitive drum. 1. An image recording apparatus characterized in that the nozzle head has a nozzle head that becomes visible when the photosensitive drum is exposed, and the nozzle head is disposed near an outer side substantially parallel to a tangent to the photosensitive drum. 2. In the image recording apparatus according to claim 1, an electrostrictive element is attached to the nozzle head containing the ink liquid or liquid colored toner, and a high-frequency electric field is applied to the electrostrictive element. The ink or liquid colored toner is ejected from the nozzle of the nozzle head, and the ejected ink or liquid toner is charged to a polarity opposite to that of the electrostatic latent image by a charging electrode disposed at the outlet of the nozzle, and the electrostatic latent image is charged. An image recording apparatus characterized in that the ink liquid causes liquid colored toner to adhere onto the photosensitive drum due to suction force generated by the latent image. 3) The image recording apparatus according to claim 1, wherein the nozzle head is reciprocated in the generatrix direction of the photosensitive drum. 4) Claims In the image recording apparatus according to item 8, a plurality of the nozzle heads are provided, each nozzle head contains a liquid toner of a different color, and the ink from the plurality of nozzle heads is An image recording apparatus characterized in that liquid or liquid toner is ejected at time intervals corresponding to a predetermined rotational speed of the photosensitive drum.