JP3486540B2 - Image recording method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording system for recording high gradation and high density reproduced images by electrophotography.

[0002]

2. Description of the Related Art Conventionally, in conventional radiation (X-ray) imaging for the purpose of medical diagnosis, an X-ray photography method in which a radiographic image is directly captured on an X-ray film or the like and a storage phosphor sheet are captured. A radiation image information recording / reproducing system that photoelectrically reads an image, processes the image, and reproduces the image on a CRT, a photographic film, or the like has been implemented, and has a great effect. On the other hand, in other systems such as CT and MR for obtaining medical images, hard copy images reproduced on photographic film are used as medical diagnostic images. In addition, hardcopy images such as electron microscope images of electron microscope image recording / reproducing system using stimulable phosphor sheet and radiation inspection system of nondestructive inspection of structures are used as diagnostic images for research or industry. It is used.

Since such diagnostic images, particularly medical diagnostic images, are required to have high image quality, that is, high density, high resolution, and high gradation, silver salt mapping type light-sensitive materials have conventionally been used and these light-sensitive materials have been used. A so-called wet system, which is a wet processing system that obtains a reproduced image by wet development after photographing or recording, has been used. This wet system reproduces high-quality and high-quality images, but since it requires a processing solution such as a developing solution and a fixing solution, it is not easy to handle. Image recording with no dry system is getting more and more attention.

Image recording by an electrophotographic system can be cited as one of the dry systems. In this electrophotographic system, basically, an electrophotographic photosensitive member is imagewise exposed to form a latent image on the photosensitive member. After developing the latent image with a toner to form a toner image, the toner image on the photoreceptor is transferred to a final image support such as paper or film, and the transferred toner image on the support is obtained as a hard copy image. Is.

[0005]

By the way, an electrophotographic monochrome reproduced image is formed by toner transferred onto a support, so that gradation is different between a toner-transferred portion and a non-transferred support portion. Since there is a limit to the gradation that can be expressed in the recording of the reproduced image by one-time exposure, development, and transfer using monochrome toner, even if the support is a reflective support such as paper. Even with a transparent support such as a film, there has been a problem in that it is not possible to produce gradations required for diagnostic images, particularly medical diagnostic images, for example, 10 bits (1024 gradations).

Further, in the above-mentioned one-pass image recording by one-time exposure and development transfer, the maximum density becomes low because the transfer amount at one time is limited, and especially in the case of the transmissive support, the maximum density is insufficient. There was a problem of doing. Generally, in order to obtain a high-quality medical diagnostic image, a maximum density of about 3.0 is required, but it cannot be achieved with one-pass image recording, and a high-quality image cannot be obtained. There was a problem.

The object of the present invention is to solve the above-mentioned problems of the prior art and, in electrophotographic image recording, also for a reflective support such as paper and a transmissive support such as a film,
An object of the present invention is to provide an image recording method that can reproduce a high-gradation high-quality image with a sufficiently high maximum density.

[0008]

To achieve the above object of the Invention The present invention provides one of the same-color toner image formed on the electrophotographic photoreceptor by electronic photographic method multiple times overlap
And transferred to the image recording medium, the toner image to a picture <br/> image recording method that records a single reproduced image, which is photographed plural rotation
Is an image in which the optical density of the toner is different,
The toner image has density throughout the input image data.
Formed by one of the toners with different optical densities
The present invention provides an image recording method characterized by the following.

Here, the toner image transferred a plurality of times
The images are preferably images with different resolutions.
Yes. The toner images transferred a plurality of times are preferably images formed by the same image data. Further, it is preferable that each of the toner images transferred a plurality of times is an image formed according to the density of the reproduced image . Also, the toner image photographed multiple rotation is preferably a different image of each toner size.

Further, the toner image photographed multiple rotation is formed as a latent image by the same laser beam at the same of the electrophotographic photosensitive member, whether an image has been developed by different toners, or the same Which is a latent image formed on the electrophotographic photosensitive member by different laser beams and developed by different toners, or formed as a latent image on each different electrophotographic photosensitive member by different laser beams. It is preferable that the images are developed by different toners.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An image recording system according to the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings. In the image recording method of the present invention, toner images of the same color formed on the electrophotographic photosensitive member are transferred onto the same final image support a plurality of times in duplicate and then fixed to form one reproduced image (hard copy). Image). First, a single hard copy image is obtained by repeating toner development of a latent image formed on a single electrophotographic photosensitive member with a single toner using a single light beam a plurality of times. The embodiment will be described.

FIG. 1 is a schematic diagram showing an embodiment of an electrophotographic image recording apparatus for implementing the image recording system of the present invention. An electrophotographic image recording apparatus (hereinafter, simply referred to as an electrophotographic apparatus) shown in FIG. 1 10, an electrophotographic photosensitive drum comprising a photoconductive member is provided on the outer peripheral surface (hereinafter, simply photoreceptor as drum) 12, an arrow As a toner image forming unit for forming a toner image on the outer peripheral surface of the photoconductor drum 12 rotated in the A direction, a corona charging device arranged on the outer peripheral surface of the photoconductor drum 12 along the rotational direction A thereof. Vessel 14,
The exposure unit 16, the toner developing unit 18, the transfer unit 20, the static eliminator 21, the cleaning unit 22, etc., and the transfer unit 20.
A supply unit 24 for supplying a final image support such as an image receiving paper or a film, fixing means 26 for fixing the toner image transferred to the final image support, and discharging the final image support on which the toner image is fixed. And a discharge unit 28.

Here, the photosensitive drum 12 has a photoconductor on its outer peripheral surface, is uniformly charged by corona discharge by the corona charger 14, and a latent image is formed by imagewise exposure of the exposure beam. This latent image is transferred to a toner image support such as an image-receiving paper or an image-receiving film after being developed with toner. It has the necessary sensitivity at the wavelength of the exposure beam and has excellent printing durability. It is preferably one. The material of the photoconductor forming the outer peripheral surface of the photoconductor drum 12 is ZnS, CdS, Se alloy, OPC (organic photoconductor), and amorphous silicon carbide (S).
iC) and the like. Corona charger 14
Is for applying a super high voltage to generate corona discharge and uniformly charge the photoconductor on the outer peripheral surface of the photoconductor drum 12. For example, a shield plate, a thin tungsten wire electrode, and if necessary, , Tungsten wire and photosensitive drum 12
It is possible to use a colontron composed of a grid which is preferably arranged between and.

The exposing means 16 exposes the outer peripheral surface (photoconductor) of the photosensitive drum 12 uniformly charged by the corona charger 14 imagewise by a light beam modulated according to image data to expose it. This is for forming a latent image on the outer peripheral surface of the drum 12. The exposure means 16 is, for example, as shown in FIG. 2, a laser light source 30 including a semiconductor laser (LD), a gas laser, and the like, and the laser light source 30.
An optical modulator 31 such as an AOM (acousto-optical light modulator) for intensity-modulating the light beam (laser beam) 15 emitted from the optical modulator 15, and a modulation circuit 32 for driving the optical modulator 31.
Optical deflection of a polygon mirror or the like for reflecting and deflecting the modulated light beam 15 and scanning it on the photoconductor drum 12 in a direction (center axis direction of the photoconductor drum 12) substantially perpendicular to the rotation direction (direction of arrow A). Device 33, a scanning lens 34 including an fθ lens that focuses the deflected light beam 15 on the photosensitive drum 12 to a uniform beam diameter, and the focused (imaging) light beam 15 falls on the photosensitive drum 12. And a stand-down mirror 35.

The optical modulator 31 is connected via a D / A converter 38 and a modulation circuit 32 according to the image recording method of the present invention. In the system of the present invention, the digital image signal Sd output from the image signal processing device 36 is used.
The output is corrected by the correction table 37, and the modulation circuit 32 generates the analog modulation signal SM for driving the optical modulator 31 based on the analog image signal S converted by the D / A converter 38. In the illustrated example, the main scanning with the light beam 15 is performed by the optical deflector 33, and the sub-scanning is performed by rotating the photosensitive drum 12 (in the A direction), but the present invention is not limited to this. Without deflecting the light beam 15 by the light deflector 33, the light beam 1
The main scanning by 5 is performed by the rotation of the photosensitive drum 12, and the sub scanning of the photosensitive drum 12 or the light source unit is performed.
It may be performed by parallel movement along the central axis of the photosensitive drum 12. When moving the light source unit, moving means for the light source unit is required, but an expensive optical deflector 3
It is not necessary to use the scanning lens 34, the scanning lens 34, and the long vertical mirror 35, and it is sufficient to use only a small-sized imaging lens and reflection mirror that are inexpensive.

Further, the method of modulating the light beam 15 is not limited to the method of using the optical modulator 31 of the illustrated example, but the laser light source 30 may be directly modulated, and the modulation method is intensity modulation ( Any modulation method such as PAM), pulse width modulation (PWM) or pulse number modulation (PNM) may be used. Further, the light source for exposure is not limited to the one using the laser light source 30 as shown in the drawing, and the photosensitive drum 12 such as a light emitting diode (LED) or an LED array is imagewise exposed to form a latent image. Any light source is possible as long as it is possible. Needless to say, an appropriate exposure optical system is used according to the exposure light source used.

The toner developing device 18 develops the latent image formed on the photosensitive drum 12 by the exposing means 16 with a toner, and a toner container 41 containing the toner 40 therein.
And a developing roller 42 attached to the tip of the toner container 41. The toner developing device 18 includes a roller 42,
It is arranged close to the outer peripheral surface of the photoconductor drum 12 on which the latent image is formed, the developing roller 42 is rotated, and the toner 40 in the toner container 41 is attached to the outer peripheral surface thereof to bring the toner 40 close to the photoconductor drum 12. , The toner 40 on the outer periphery of the developing roller 42
Is moved by electrostatic attraction and adhered to the latent image on the photoconductor drum 12, so that the latent image is developed with toner and a toner image is formed on the photoconductor drum 12. The toner 40 used in the present invention is particles containing a coloring material such as carbon black and a pigment and a resin as a main component, but if the dense printing can be stably performed for a long time, it is easy to handle, and the printing quality is good, it is not particularly limited. Any toner may be used, and a one-component system in which only toner is used, or a two-component system in which insulating toner particles and triboelectric particles (carriers) are mixed may be used. Also, the particle size of the toner particles used in the present invention is not particularly limited, but it is preferable that the toner particles are fine particles whose particle diameters are as uniform as possible.

Further, the developing method of the electrostatic latent image on the photosensitive drum 12 is not limited to the one using the toner developing device shown in the drawing, and any conventionally known developing method may be used. For example, as a developing method, typically, a two-component developing method utilizing triboelectrification such as a cascade developing method, a magnetic brush developing method, a fur brush developing method, a pressure roller developing method and a microtoning method is also used. Inductive charging development with magnetic toner, impression development, jumping development, BMP (Bipolar Magnetic Toner) development, and other insulating toner development methods such as one-component development using triboelectric charging are also available as powder. An aerosol developing method using air or mist as a carrier, such as a cloud developing method and a mist developing method, can also be used.

The transfer means 20 transfers the toner image formed on the photoconductor of the photosensitive drum 12 to the surface (photoconductor) thereof.
Is to be peeled off from the toner and transferred to a toner image support 43 such as an image receiving paper or an image receiving film. A predetermined direct current voltage having a polarity opposite to the charge polarity of the toner 40 is applied to the outer peripheral surface of the photosensitive drum 12. An endless conductive belt 44 that presses the image receiving surface of the support body 43 with a predetermined pressure, and nips and conveys it between the photosensitive drum 12 and the photosensitive drum 12 as the photosensitive drum 12 rotates.
Three rollers 45, 4 around which the conductive belt 44 is stretched
5 and 45. In addition, the image support 43 is replaced with the toner 4
In order to charge the opposite polarity to the charge polarity of 0, the conductive belt 4
The method of applying a predetermined DC voltage having a polarity opposite to the charge polarity of the toner 40 to the toner 4 is not particularly limited, and any conventionally known method and means may be used. For example, three rollers 45, 45, 45 may be an insulating roller, and a means for directly applying a voltage of a required polarity by contacting the conductive belt 44 may be provided, or one of the three rollers 45, 45, 45 for stretching the conductive belt 44 may be provided. A conductive roller may be used, and a voltage having a required polarity may be applied to the conductive roller. Further, the transfer method of the transfer means 20 used in the present invention is not limited to the method using the conductive roller belt in the illustrated example, and any means and method can be used as long as the image support 43 can be charged in a polarity opposite to that of the toner 40. For example, instead of using the conductive belt 44, a conductive roller is directly used, and the conductive roller is sandwiched between the photoconductor drum 12 and the conductive roller while applying a DC voltage and pressure of a required polarity. The conveying bias roller transfer method may be used, or the corona discharge transfer method using a colontron may be used.

Static eliminator 21 and cleaning means 22
Is for removing and cleaning the toner remaining on the photoconductor on the outer peripheral surface of the photosensitive drum 12. Here, the static eliminator 21 weakens the adhesion force (for example, Coulomb force) between the photoconductor drum 12 and the residual toner, so that the charge removal of the photoconductor drum 12 and the residual toner is performed prior to the removal of the residual toner. Therefore, conventionally known means and methods such as a colontron for corona discharge and a lamp for light irradiation can be used. Also, the cleaning means 2
Numeral 2 physically removes the residual toner from the outer peripheral surface of the photosensitive drum 12. What is required is to damage the photoconductor on the outer peripheral surface of the photosensitive drum 12 or to deteriorate the characteristics. However, for example, a contact removing means such as a brush, especially a fur brush, a blade, especially a doctor blade, a web and a roll, a non-contact removing means using an air jet and ultrasonic waves, a magnetic brush or a bias. Well-known cleaning means and methods such as a contact removing means that takes electrostatic force into consideration such as a brush can be used. Which cleaning means and method should be used may be appropriately selected in consideration of the mechanical strength and characteristics of the photoconductor on the outer peripheral surface of the photosensitive drum 12.

The final image supporting member supplying section 24 supplies the final image supporting member 43 such as an image receiving sheet or an image receiving film to the photosensitive drum 12 on which the toner image is formed and the transfer means 20, and a plurality of cut sheets. Image support 43
46 for accommodating paper, a draw-out roller 47 for separating one image support 43 in the magazine 46, and a draw-out roller 4
It has a pair of nip rollers 48 that nip and convey the image support body 43 taken out one by 7 to the photosensitive drum 12 and the transfer means 20. The configuration of the supply unit, supply means, and supply method of the final image support 43 are not particularly limited, and for example, a long image support wound in a roll shape that is not cut may be used directly or directly. It may be configured to be cut into a predetermined size and supplied.

The fixing means 26 melts and solidifies the toner image transferred onto the final image support to fix it. In the illustrated example, the fixing means 26 is arranged in the conveying path on the output side of the transfer means 20.
At least one of the heat rollers is a heat roller pair 49. In general, the fixing unit 26 applies heat, pressure, a solvent, or the like to the toner image transferred to the final image support to melt or melt the toner particles to combine the toner particles, and the melted product is used as an image receiving film or The surface of the image support 43 such as the image receiving paper is wetted, and the melt is adhered to the surface. In particular, if the image support 43 has an uneven surface such as the image receiving paper, it is immersed in the uneven surface. After that, the supply of heat, pressure, solvent or the like to the toner is stopped, and the toner is solidified on the image support 43, whereby the fixing is completed. Therefore, the fixing means 26 used in the present invention is not limited to the heat roller pair 49 in the illustrated example, and may be anything as long as it exhibits the above-described fixing action, for example, other heat roller fixing (method) means, Thermal fixing (method) of infrared lamps and xenon flash lamps
Conventionally known fixing methods and means such as means, pressure fixing (method) means, solvent fixing (method) means and the like can be mentioned. In the case of the image support 43 whose image receiving surface is a smooth surface such as an image receiving film, the smooth surface is roughened in advance or the adhesive action of the melt of the toner particles is strengthened. Is preferred.

The discharging portion 28 is a portion for discharging the final image support having the toner image fixed by the fixing means 26 to the outside of the apparatus, and the toner image fixed and conveyed by the heat roller pair 49 is fixed. A discharge roller pair 50 configured to sandwich and convey the hard copy image formed of the image support 43 and discharge the hard copy image to the outside of the apparatus, and a tray 51 that receives the hard copy image discharged to the outside of the apparatus by the discharge roller pair 50. Needless to say, the discharge unit 28 is not limited to the illustrated example.

The feature of the present invention resides in that one hard copy image is formed by transferring a plurality of toner images with the same toner to the same final image support 43 using the image recording apparatus 10 of the illustrated example. It is to reproduce. Therefore, the features of the image recording apparatus 10 of the illustrated example necessary for carrying out the features of the invention will be described in more detail. First, the image signal processing device 36 of the exposure unit 16
It has a function of generating image data necessary for one toner image formation based on the density of the hard copy image to be reproduced on the final image support 43 and the number of toner images transferred to the same support 43.

Here, the image data necessary for one toner image formation generated in the image signal processing device 36 is
The same image data can be used in any of the toner image formations performed a plurality of times. In this case,
As shown in (a), it is possible to raise the gradation of the reproduced image and increase the maximum density. Further, in the image signal processing device 36, it is divided into the density regions of the image to be reproduced and
The image data of the second time, the second time, ... May be generated. That is, the number of times of transfer may be reduced when the density to be reproduced is low, and the number of times of transfer may be increased when the density is high. In this case, as shown in FIG. 3B, the maximum density can be increased without changing the gradation of the reproduced image so much.

When forming a toner image a plurality of times,
The resolution of the toner image formed once may be changed. The method for changing the resolution of the toner image each time is not particularly limited and may be a conventionally known method. For example, the toner image is changed by changing the scanning pitch, the recording density, the screen ruling, the halftone dot density, or the like. It may be configured to be formed. The expression of the image density in the present invention is not particularly limited and may be any conventionally known one. In this case, the image data corresponding to these,
Main scanning speed by the light deflector 33 and the photosensitive drum 1
It is only necessary to generate a sub-scanning speed by 2 and perform image exposure by the exposing means 16 using these data, and after the latent image is formed, toner development is performed to form a toner image having a different resolution each time. In this case, needless to say, the drive motors of the optical deflector 33 and the photoconductor drum 12 are controlled so that the rotational speeds thereof are appropriate. As described above, in the present invention, since the toner image is formed a plurality of times with the same image data or by dividing the density area of the reproduced image or changing the resolution, it is possible to increase the maximum density of the reproduced image. , A sufficient image gradation, for example, a 10-bit gradation required for a medical diagnostic image can be obtained. Therefore, the reproduced image obtained in the present invention can be a high gradation high quality image having a sufficiently high maximum density.

Further, in the present invention, the photosensitive drum 1
It is necessary to transfer the toner image on the photosensitive drum 12 again onto the image support 43 to which the toner image on 2 has been transferred. Therefore, the toner image transfer support 4 is once discharged to the tray 51 of the discharge unit 28 or before being discharged.
3 is configured such that the transfer means 20 and the transport means of the supply unit 24 can be transported in the reverse direction, or is transported by providing a completely different reverse transport path, and is automatically stored in the magazine 46 of the supply unit 24. You may let me. Alternatively, a standby section for waiting the toner image transfer support 43 fed back to the transport path between the transfer means 20 and the supply section 24, the transport path connected to this transport path, or the completely different reverse transport path described above, or It may be configured to provide an intermediate tray. The toner image transfer support 43 may be fed back after the fixing process by the fixing unit 26 or before the fixing process. However, when the toner image transfer support 43 is fed back before the fixing process, the toner image transfer support 43 is always fixed at the end. It goes without saying that processing is performed. According to the first embodiment of the present invention, toner development of a latent image formed on one electrophotographic photosensitive member by using one light beam is repeated a plurality of times to obtain one hard image. The image recording method for obtaining a copy image and the image recording apparatus 10 for implementing the same are basically configured as described above.

Next, FIG. 4 shows a case where one light beam is used.
According to the second embodiment of the present invention, a plurality of latent images formed on one electrophotographic photosensitive member, in this case, toner development with three kinds of toner of the same color is repeated a plurality of times to obtain one hard copy image. An example of an image recording apparatus that implements an image recording method will be described. The image recording device 60 shown in FIG.
The image recording apparatus 10 shown in FIG. 6 is the same as the image recording apparatus 10 except that the supply unit 24, the fixing unit 26, and the discharge unit 28 are omitted. Is attached and the description thereof is omitted. Needless to say, the image recording device 60 shown in FIG. 4 includes the supply unit 24, the fixing unit 26, and the discharge unit 28, which are not shown.

The image recording apparatus 60 shown in FIG. 4 has three toner developing units 18a, 18b, 18c, and each developing unit 1
8a, 18b and 18c are toners 40a and 40, respectively.
toner container 41a, 41 containing b, 40c therein
b, 41c and developing rollers 42a, 42b, 42c. Therefore, the three toner developing devices 18a, 18
By using the same toner for the toners 40a, 40b, 40c of b, 18c, the image recording method of the first embodiment of the present invention described above can be similarly implemented.
Each toner 4 of one toner developing device 18a, 18b, 18c
By setting 0a, 40b, and 40c to be the same color but different from each other, it is possible to increase the degree of freedom in the gradation expression of the reproduced image and obtain a higher gradation high-quality image.

For example, if the toners 40a, 40b, 40c are toners of the same color having different particle sizes (particle diameters) of the toner particles, and if the toners of a small size alone produce too much gradation, they will have a large size. Toner can be roughened to a certain extent, and small-sized toner can be finely tuned to soften the gradation to a certain extent, and it is possible to prevent graininess deterioration that appears when only large-sized toner is used. It is possible to improve the image quality by achieving both gradation and graininess. Of course, if the toners 40a, 40b, and 40c are toners of the same color, not only the size of the toner particles but also the type of the toner particles may be changed. Further, the toners 40a, 40b, 40c may be toners having different optical densities. By doing so, it is possible to improve the image quality by adjusting the gradation of the toner image. Further, the image recording apparatus 60 of the illustrated example has three toner developing devices 18a, 18b, 18c, but the number of toner developing devices provided is not limited and may be any number.
There may be any number of different sizes and types of toner and optical density contained therein. The image recording system of the second embodiment of the present invention and the image recording apparatus for implementing the same are basically configured as described above.

Next, FIG. 5 shows that a latent image formed on a plurality (three) of electrophotographic photoconductors by using a plurality (three) of light beams is toner-transferred with a plurality of (three) kinds of toner of the same color. An example of an image recording apparatus for carrying out the image recording method of the third embodiment of the present invention in which development is repeated a plurality of times to obtain one hard copy image will be described. The image recording apparatus 70 shown in FIG. 5 is basically the same as the image recording apparatus 10 shown in FIG. 1 except that the transfer unit 20, the supply unit 24, the fixing unit 26, and the discharge unit 28 are removed, although the size is different. The transfer units 20 are arranged in parallel and the transfer unit 20 is commonly used. Since the transfer units 20 are the same except for these points, the same components are denoted by the same reference numerals and the description thereof will be omitted. The image recording device 70 shown in FIG.
Needless to say, 4, the fixing unit 26 and the discharge unit 28 are provided.

The image recording apparatus 70 shown in FIG. 5 has three photoconductor drums 12a, 12b, 12c, and corona chargers 14a, 14b, 14c and light beams 15a, 15b, 15c on the outer peripheral surfaces thereof. Exposure means 16a, 16b, 16c for ejecting respectively, and toner developing devices 18a, 16
b, 16c, static eliminators 21a, 21b, 21c and cleaning means 22a, 22b, 22c. The common transfer means 72 includes a pair of conveying rollers 74, 74 arranged on both sides and the conveying roller 7.
The endless conductive belt 76 stretched around 4, 74 is arranged inside the pair of conveying rollers 74, 74, and the pressing force of the endless conductive belt 76 on the three photosensitive drums 12a, 12b, 12c is adjusted. The tension rollers 73, 73 and the conductive roller 75 for applying a predetermined DC voltage to the conductive belt 76 are provided. The image recording apparatus 70 shown in FIG. 5 uses the same toner or toner of the same color and different sizes or types, so that the image recording methods of the above-described first and second embodiments of the present invention are the same. The image recording apparatus (10 and 60) that implements these can perform the operation quickly or at high speed.

The image recording device 70 for carrying out this embodiment is used.
It is needless to say that the transfer means used in FIG. 5 is not limited to the transfer means 72 shown in FIG. 5, and conventionally known transfer means and methods can be applied similarly to the transfer means 20 shown in FIGS.

Although the image recording method of the present invention has been described in detail above, the present invention is not limited to this, and various changes and improvements may be made without departing from the scope of the present invention. Of course.

[0035]

As described in detail above, according to the present invention,
In electrophotographic image recording, which is a dry system, even when the paper and transparent film are used as the final image support, the maximum density can be sufficiently increased to, for example, about 3.0, and the gradation is also increased. High enough, eg 10
It is possible to output up to about a bit, and it is possible to reproduce a high-density, high-gradation, high-quality image extremely easily and surely as compared with a conventional wet system that performs wet development processing. Further, according to the present invention, by using toners of different types and sizes, a problem of deterioration of graininess such as roughness of reproduced image due to use of large size toner and reproduced image due to use of small size toner It solves all the gradation problems and the deterioration of toner image transfer at once,
Graininess, gradation and transferability can be enhanced. Therefore, the electrophotographic image obtained by the method of the present invention can be suitably applied to a diagnostic image that requires high density, high gradation and high image quality, particularly a medical diagnostic image.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an embodiment of an image recording apparatus that implements an image recording method according to the present invention.

FIG. 2 is a schematic perspective explanatory view of an example of an exposure unit used in the image recording apparatus shown in FIG.

3 (a) and 3 (b) are graphs showing different effects of the present invention.

FIG. 4 is a schematic diagram of another embodiment of the image recording apparatus that implements the image recording method according to the present invention.

FIG. 5 is a schematic diagram of another embodiment of the image recording apparatus that implements the image recording method according to the present invention.

[Explanation of symbols]

10, 60, 70 image recording device 12, 12a, 12b, 12c Electrophotographic photosensitive drum 14,14a, 14b, 14c Corona charger 16,16a, 16b, 16c Exposure means 18, 18a, 18b, 18c Toner developing device 20,72 Transfer means 21, 21a, 21b, 21c Static eliminator 22, 22a, 22b, 22c Cleaning means 24 Supply Department 26 fixing means 28 Discharge part

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-8-171252 (JP, A) JP-A-5-35038 (JP, A) JP-A-7-295326 (JP, A) JP-A-62-1 55670 (JP, A) JP 6-108378 (JP, A) JP 6-161203 (JP, A) JP 62-92967 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 15/00 303 G03G 21/00 370-540 G03G 15/01-15/01 117 H04N 1/23-1/31

Claims (8)

(57) [Claims] 1. A duplicate of one multiple of the same color toner image formed on the electrophotographic photoreceptor by electronic photographic system
And transferred to an image recording medium, a picture image recording method that records a single reproduced image, the toner image photographed multiple rotation, the toner respectively
The toner images are images having different optical densities, and the toner images have densities throughout the input image data.
Formed by one of the toners with different optical densities
An image recording method characterized in that the image is recorded. 2. The image recording system according to claim 1, wherein the toner images transferred a plurality of times have different resolutions. The toner image wherein the photographed plurality rotated, claim 1 or the same image data image formed on the basis of
Or the image recording method described in 2 . The toner image wherein the photographed plurality rotated, an image recording method according to any one of claims 1 to 3 which is an image formed in accordance with the concentration of each of the reproduced image. 5. The image recording system according to claim 1, wherein the toner images transferred a plurality of times have different toner sizes. Wherein said toner image photographed multiple rotation are formed on the same said electrophotographic photosensitive member on a same latent image by a laser beam, according to claim 1 to 5 are images developed by different toners The image recording method according to any one of 1. Wherein said toner image photographed multiple rotation is formed as a latent image in the same said electrophotographic photosensitive member onto a different laser beam, respectively, claims 1 to 5 which is an image that has been developed by different toners The image recording method according to any one of 1. The toner image 8. is photographed plural rotation is formed as a latent image by different laser beam respectively on different said electrophotographic photosensitive member, respectively, claims 1 to 5 which is an image that has been developed by different toners The image recording method according to any one of 1.