JP2001147585A - Image forming method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable image forming method by which the device constitution becomes simple and high image quality is obtained. SOLUTION: As a method for forming a color image by using a contact type non-magnetic one-component developing device, a plate-like blade which is constituted of a metallic elastic member and the tip part of which is chamfered is used by being combined with developer consisting of toner whose glass transition point is 55 to 70 deg.C, whose weight average grain diameter is 6.0 to 10.0 μm and whose grains having grain diameter being <=5 μm are <=20 number % in the developing device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming an image according to an electrophotographic method. More specifically, the present invention relates to a method and an apparatus for forming an image on a developing roller using a toner layer thickness regulating blade having a specific structure. The present invention relates to a color image forming method and apparatus for regulating and visualizing an electrostatic latent image formed on an image carrier using, for example, a non-magnetic one-component developer.

[0002]

2. Description of the Related Art Recently, with the progress of office automation, electrophotographic image forming apparatuses such as laser printers have been widely used as computer output terminals, facsimile machines, copiers and the like. These image forming apparatuses generally include a charger for uniformly charging a photosensitive drum as an image carrier, an exposure apparatus for forming an electrostatic latent image on the photosensitive drum by irradiating light, and an electrostatic device on the photosensitive drum. A developing device that develops the latent image with a developer (toner) and visualizes the latent image;
An image transfer device that transfers the toner image formed on the photosensitive drum by development to a recording medium such as recording paper, and an image fixing device that fuses the transferred toner image on the recording medium and fixes the image thereon are provided. ing. Further, the developing device is usually provided with a developing roll disposed opposite to and in contact with the photosensitive drum, a toner container for storing toner, a toner supply device for supplying toner to the developing roll, and a developing roller. It consists of a toner layer thickness regulating blade that controls the thickness of the supplied toner.By electrically attaching uniform toner to the electrostatic latent image on the photosensitive drum from the toner layer on the developing roll, Development, that is, visualization of the electrostatic latent image can be performed. Further, in order to use the used photosensitive drum after the transfer of the toner image in the next image forming step, around the photosensitive drum, a static eliminator for removing charges from the surface of the photosensitive drum and stripping off the residual toner A cleaning device is also provided.

Conventionally, a developing device used in an image forming apparatus as described above includes a device designed to use a one-component developer consisting of only a toner and a two-component developer consisting of a combination of a toner and a carrier. There are devices designed to use agents. Since the one-component developing device does not use a carrier, it is not necessary to pay particular attention to the deterioration of the carrier, the mixing of the carrier and the toner, and the mixing ratio at that time. Therefore, the size of the device can be reduced and the manufacturing cost can be reduced. , There are advantages. Further, when the developer used is non-magnetic, the transparency of the toner is high, so that there is an advantage that a high-quality color image can be formed.

When a one-component developing device is used, since the one-component developer used has no carrier, a developer in which a carrier and a toner are mixed is used as in a two-component developing device. Unlike the method in which the developer is attached to the magnet roller, a step of forcibly charging the developer and applying a charge to the developing roller to attach the developer is required. For this reason, in the one-component developer, a toner having a relatively high volume solid resistance is used. Also, for example, from 10 ¹⁰ Ωcm to 10 ¹³
When a toner having a volume solid resistance of Ωcm or more is used, it is necessary to forcibly charge the toner to a predetermined polarity. Has been deployed.

[0005] As the frictional charging member, for example, a blade for uniformly regulating the toner adhered on the developing roller to a predetermined thickness, a charging member exclusively used only for frictional charging of the toner, and the like are used. Of these, the simplest configuration is one that regulates the toner layer thickness by regulating the toner layer thickness by a blade that regulates the toner to a predetermined thickness.
And cost reduction is possible. As will be understood from the following description, the toner layer thickness regulating blade used in the developing device in the embodiment of the present invention exclusively has a function of regulating the toner layer thickness or has a function of exclusively triboelectric charging. And those having both functions of regulating the layer thickness and triboelectric charging.

A developing device (part) equipped with a conventional toner layer thickness regulating blade is schematically shown in FIGS. 1 to 5, for example. In the developing device shown in FIG.
mm blade 50 made of resin or metal with relatively high hardness
Are mounted in a blade guide 51 via a coil spring 52 so as to be freely retractable. The blade 50 is in pressure contact with the developing roller 2 rotating in the direction of arrow B at a constant pressure. Further, the developing roller 2 is rotatable in contact with an image carrier (typically, a photosensitive drum) 1 which is provided opposite thereto and rotates in the direction of arrow A.

In the developing device of FIG. 2, the tip of the leaf spring is L
A blade 50 shaped like a letter is used. In this apparatus, one end of a blade 50 is fixed to a blade holder 51 made of a highly rigid material, and an L-shaped edge as the other end of the blade 50 is pressed against the developing roller 2 at a constant pressure by its elasticity. In the developing device shown in FIG. 3, a blade 50 made of an elastic material such as rubber is adhered to one end of a blade holder 51 so as to extend, and the leading end of the blade 50 is pressed against the developing roller 2.

[0010] In the developing device shown in FIG.
A blade 50 shaped like a letter is used. In this apparatus, one end of a blade 50 is fixed to a blade holder 51 made of a highly rigid material, and the U-shaped surface, which is the other end of the blade 50, is pressed against the developing roller 2 at a constant pressure by its elasticity. Further, in the developing device of FIG. 5, one end of a blade 50 made of a leaf spring is fixed to the blade holder 51, and the tip of the blade 50 is subjected to round edge processing so as to be rounded (not shown). An edge portion is pressed against the developing roller 2 with a constant pressure.

However, the toner layer thickness regulating blades used in the developing devices shown in FIGS. 1 to 5 have problems to be solved. For example, the toner layer thickness regulating blade shown in FIG. 1 has a problem of distortion of the developing roller due to the generated creep, generation of horizontal streaks due to the distortion, and generation of “fog” due to unevenness of the toner layer thickness. The blade of FIG. 2 suffers from toner degradation due to fine cracks at the L-shaped edge. Further, the blade shown in FIG. 3 has a problem such as a decrease in frictional charging ability due to the generated creep. Further, the blade shown in FIG. 4 has a problem such as toner sticking due to the limit of flatness. Further, the blade shown in FIG. 5 has a problem that the thickness of the toner varies due to the limit of the flatness and the occurrence of “fogging” due to the variation.

The above problem is a serious problem particularly when a non-magnetic one-component developer is used. This is because, when such a developer is used, the toner layer thickness regulating blade can be uniformly pressed against the developing roller with a constant pressure to uniformly regulate the toner thickness to a predetermined thickness. This is because it must be capable of being uniformly charged without deteriorating the deterioration of the toner.

The resolution required for a one-component developer has been improving year by year in digital copiers and printers in recent years. Therefore, the demand for small particle size toners has been increasing. Recently, the weight average particle size is mainly about 6.
Smaller particle size toners in the range of 0-10.0 μm are increasingly used in these devices. Further, with the energy saving of the apparatus, a toner which can be fixed at a low temperature is desired, and the thermal characteristics of the toner have been reduced in temperature in conjunction with the colorization.

Under these circumstances, the developing apparatus described above with reference to FIGS. 1 to 5 has a "weight average particle diameter of 6.0 to 10.0 .mu.m and a low thermal characteristic as described above. When using toner (that is, a toner that can be fixed at a low temperature), by rotating the developing roller while pressing the blade against the developing roller for a long period of time, the toner receives heat / mechanical stress when passing through the blade, As a result, the toner is fused to the tip of the blade as printing is performed, and the stable formation of the toner layer on the photosensitive drum is hindered.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art as described above. A first object of the present invention is to provide a toner layer thickness regulating blade capable of exhibiting the function of regulating the layer thickness or the function of triboelectric charging or both of them, having a weight average particle diameter of 6.0 to 10.0 μm and low thermal characteristics. An object of the present invention is to provide an image forming method which can be used in combination with a toner, has a simple structure of the apparatus, can obtain high image quality, and has high reliability.

A second object of the present invention is to provide an image forming apparatus suitable for carrying out the image forming method of the present invention. The above and other objects of the present invention can be easily understood from the following detailed description.

[0015]

According to one aspect of the present invention, there is provided an image forming method for forming a color image in accordance with an electrophotographic method using a contact-type non-magnetic one-component developing device. A flat blade made of a metal elastic member and having a chamfered tip is used as the toner layer thickness regulating blade, and the glass transition point (Tg) of the toner is 55 to 70 ° C. as a developer. Having a weight average particle size of 6.0 to 10.0 μm and a
m. The use of a developer having 20% by number or less of particles having a particle size of not more than m provides an image forming method.

Further, according to the present invention, there is provided an image forming apparatus equipped with a contact type non-magnetic one-component developing device for forming a color image in accordance with an electrophotographic method, wherein the developing device comprises a metal layer elastic member as a toner layer thickness regulating blade. The developer contained in the developing device has a glass transition point (Tg) of 55 to 70 ° C., and has a weight average particle size. Provided is an image forming apparatus, wherein the developer has a diameter of 6.0 to 10.0 μm and particles having a particle diameter of 5 μm or less are 20% by number or less.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The image forming method and apparatus according to the present invention form a color image according to an electrophotographic method using a contact type non-magnetic one-component developing apparatus. The mechanism of image formation in the method and apparatus of the present invention is basically the same as the mechanism of contact-type non-magnetic one-component development generally known in the art, as described below.

In the image forming method and apparatus according to the present invention,
The following two requirements: (1) The toner layer thickness regulating blade used in the contact type non-magnetic one-component developing device is made of a metal elastic member and its tip is chamfered; The developer contained in the apparatus and used for image formation has a toner having a glass transition point (Tg) of 55 to 70 ° C., a weight average particle diameter of 6.0 to 10.0 μm, and a particle size of 5 μm or less. It is essential that the developer has 20% by number or less of particles having a particle size.

First, the toner layer thickness regulating blade is formed from an arbitrary metal elastic member. Suitable metal elastic members include, for example, steel, especially stainless steel for springs. This is because this member has excellent elasticity which cannot be obtained with conventional blade materials, and is easy to process. The toner layer thickness regulating blade is usually used after being processed into a flat plate shape. A part of the tip of the flat blade is chamfered by a conventional processing method, and the chamfered portion is further subjected to polishing.
As the polishing treatment, various techniques commonly used in the field of machining can be used, but preferably, buff polishing can be used. Buffing can be performed by applying a buffing abrasive to the surface of a polishing wheel made of cloth or other materials, and depending on the desired degree of polishing, using base polishing, finishing polishing, or gloss polishing properly Can be. As the buffing abrasive, a solid abrasive in which the abrasive is mixed with oil or fat or a liquid abrasive in which the abrasive is dispersed in an emulsion can be used.

FIG. 6 is a cross-sectional view schematically showing a preferred example of the toner layer thickness regulating blade as described above. The toner layer thickness regulating blade 5 is formed by machining (chamfering) one end of a plate-shaped member made of stainless steel for spring as shown in the figure, and the chamfered surface 5a is appropriately buffed. Finished to surface roughness. When the blade 5 is pressed against the developing roller 2 rotating in the direction of the arrow B at a constant pressure, the gap formed between the developing roller 2 and the chamfered surface 5a of the blade 5 is filled with the toner 4, preferably one toner particle. As shown in the figure, the toner layer 4 having a constant thickness can be formed stably as shown.

Chamfer surface 5a of toner layer thickness regulating blade 5
Although the surface roughness Ra can be widely changed according to the size of the blade 5 and the desired effect, it is usually 3 μm when the thickness t of the blade 5 is 1 mm.
The following is preferred. Toner layer thickness regulating blade 5
Can be arranged at various positions with respect to the developing roller 2, but as shown in FIG. 6, the chamfered surface 5 a of the toner layer thickness regulating blade 5 is arranged so as to be located on the normal line of the developing roller 2. Is preferred. In FIG. 6, the surface of the developing roller 2 is linearly (originally, curved) for ease of explanation.

As shown in FIGS. 7 and 8, the toner layer thickness regulating blade 5 is arranged at a position where the edge of the chamfered portion of the toner layer thickness regulating blade 5 comes into contact with the developing roller 2 as necessary. Is also good. For example, in the case of the blade 5 in FIG. 7, the edge P1 is pressed against the surface of the developing roller 2.
In the case of the blade 5 in FIG. 8, the end side P2 is pressed against the surface of the developing roller 2. In each case,
Since an appropriate amount of the toner 4 passes through a gap formed between the developing roller 2 and the chamfered surface 5a of the blade 5, the toner layer 4 having a constant thickness can be stably formed.

Further, the chamfered amount of the chamfered portion of the toner layer thickness regulating blade 5 can be widely changed depending on the desired effect and the like. When the chamfer amount in the width direction of No. 5 is h2 (see FIG. 6), it is preferable that the chamfer amount satisfy the following relationship: 1 ≦ h2 / h1 ≦ 5. If the chamfer amount is too small or too large, the toner layer 4 cannot be formed in a satisfactory state.

Further, the toner layer thickness regulating blade is
Instead of the chamfering as described above, a flat metal elastic member such as stainless steel for a spring may be formed by punching using a press-type punch and die. At this time, it is preferable that the clearance between the punch and the die is set such that an arc-shaped curved surface having a smooth curve formed by punching when the elastic member is punched is formed. After a blade having a desired shape is obtained by punching, a polishing process is performed on a portion in contact with the developing roller. This polishing treatment can also advantageously use the buff polishing described above.

In the practice of the method and apparatus of the present invention, the developer contained in the developing apparatus and used for image formation has a glass transition point (Tg) of 55 to 70 ° C. and a weight average particle diameter of the toner. 6.0-10.0 μm and 5 μm
A developer (toner) having 20% by number or less of particles having the following particle diameters.

When the Tg of the toner used in the present invention is higher than 70 ° C., not only is it difficult to obtain a gloss, but also a high fixing temperature needs to be set, and a large amount of energy is consumed for fixing the toner image. In particular, when a color toner image is to be formed, color transparency is poor and the color reproduction range is narrow. On the other hand, when the Tg is lower than 55 ° C., even if the toner layer thickness regulating blade particularly proposed in the present invention is used, the toner is fused to the tip of the blade and the toner layer is stably formed. , And so-called “white streaks” occur, and image quality is degraded.

The toner has a weight average particle diameter of 6.0 μm.
Particles having a particle size of less than 5 μm or less
Even when the number exceeds%, the toner is fused to the tip of the blade, and the stable formation of the toner layer is hindered, and “white streaks” are generated to lower the image quality. Conversely, when the weight average particle diameter of the toner exceeds 10.0 μm, an image in which characters and thin lines are noticeably thickened is obtained.

As described above, the image forming method and apparatus according to the present invention can be carried out in accordance with the mechanism of contact-type non-magnetic one-component development generally known in the art. The method and apparatus of the present invention are particularly advantageous for forming an electrostatic latent image in accordance with an electrophotographic method, and for visualizing the electrostatic latent image with a developer to form a multicolored toner image. Can be. The formation of the color toner image is not limited to the ones listed below, but is performed in one development step, that is, each of the single color toners of yellow, magenta, cyan, and black on one photosensitive drum. An on-drum color superimposition method in which an image is formed and then transferred, or a single color toner image is formed in an independent development process, and the obtained single color toner images are superimposed to form a multicolor image. A tandem system (four-drum system) for forming a toner image can be employed. For example, the formation of a color toner image by the tandem method can be performed as follows.

A sequence of the following steps is carried out for each of the single-color toner images of yellow, magenta, cyan and black: (1) a charging step for imparting photosensitivity to an image carrier (electrostatic recording medium); And (3) an exposure step (latent image forming step) of exposing the image carrier to an image to form an electrostatic latent image and recording the electrostatic latent image, and (3) a developer ( Toner) is electrically suctioned to form an electrostatic latent image that is physically visualized.
(4) an image transfer step of sequentially transferring and superimposing the visualized toner image on the image carrier onto a recording medium such as recording paper, and (5) an image fixing step of heating and fixing the transferred image on the recording medium. carry out.

The first charging step starts with preparing an image carrier. The image carrier is a basic component of the image forming apparatus, and is typically a photosensitive drum or the like. For example, the photosensitive drum can be formed by using an aluminum drum as its core metal, finishing its surface in a mirror-like manner, and applying a layer of a photosensitive material. As the photosensitive material, for example, selenium, zinc oxide, cadmium sulfide, organic photoconductor (OPC), amorphous silicon, or the like is used. As the photosensitive material applying method, for example, evaporation, coating, or the like is used. can do.

As a charging device used to uniformly charge the image carrier, a corona charger or a conductive brush charger is used. The conductive brush charger is
Unlike the corona charger, there is no problem of generating ozone, so that it can be advantageously used in the practice of the present invention. More specifically, the conductive brush charger can charge the image carrier to a required potential by applying a voltage of 500 to 1.5 kV to the conductive brush. The conductive brush may be used in the form of a conductive roller rotatable by winding conductive fibers (for example, rayon fiber, polyester fiber, etc.) planted on a base cloth around a conductive core rod, Otherwise, the conductive fibers may be bundled and fixed like a brush, and used in the form of a plate (bar) brush. In the latter case, the size and price can be further reduced as compared with the former.

Subsequently, the charged image carrier is exposed to an image to form an electrostatic latent image and is recorded. In this exposure step, various exposure methods can be used depending on the latent image forming step to be used. Generally, a semiconductor laser optical system, an LED optical system, a liquid crystal shutter (LCS) optical system, or the like can be used as an exposure source. After the completion of the exposing step, a developing step of electrically attracting the developer to the electrostatic latent image recorded on the image carrier and physically visualizing the electrostatic latent image is performed. This step can be carried out using various apparatuses, like the other steps of the method of the present invention. The developing device is typically provided with a toner container defined by a casing (toner hopper, in which a non-magnetic one-component developer specifically defined in the present invention is used, although the developing method may vary depending on the developing method or the like). The image carrier that can form and hold an electrostatic latent image and is in contact with the image carrier that can transport the developer to a development area on the image carrier. A developer supply member disposed so as to face the developer carrier, a developer supply member capable of supplying the developer in the toner container to the developer support, and being movably disposed in elastic contact with the developer support; The toner layer thickness regulating blade which regulates the thickness of the developer on the developer carrier supplied from the supply member is also defined in the present invention.

Here, the developer carrier which can transport the developer to a developing area on the image carrier such as a photosensitive drum and which is to be opposed to the image carrier is preferably formed of a conductor. , Typically, a developing roller, a developing sleeve, and the like. For example, the developing roller can be formed by using an aluminum roller as its core metal and applying a resin coating to its surface. If necessary, a fiber brush or the like may be planted on the surface of the roller.

Further, the developer supply member which can supply the developer in the toner container to the developer carrier and which is to be movably arranged in elastic contact with the developer carrier is preferably formed of a conductor. , Typically sponge rollers, fur brushes and the like. For example, a sponge roller uses an aluminum roller as its core metal, and applies a porous resin coating to the surface thereof, or substantially the entire roller is made of an elastic sponge material, for example, urethane foam. , Can be formed.

Further, the toner layer thickness regulating blade used for regulating the thickness of the developer supplied from the developer supply member to the developer carrying member is made of a metal elastic member and has a tip as described above. The blade is a flat blade having a chamfered portion, and the blade described above with reference to FIGS. 6 to 8 is particularly preferably used. The developing device used in the embodiment of the present invention may include, for example, a toner stirring mechanism, a toner concentration control mechanism, a toner replenishment mechanism, a development bias control mechanism, and the like in addition to the above-described typical components. it can. Note that these mechanisms are well known to those skilled in the art, and a description thereof will be omitted.

After the electrostatic latent image on the image carrier is visualized to form a toner image, the toner image is electrostatically transferred to a recording medium such as recording paper and recorded. Examples of the electrostatic transfer method include a corona transfer method, a roller transfer method, and a belt transfer method. In the tandem method described here, the transfer process is performed such that the single-color toner images of yellow, magenta, cyan, and black are sequentially superimposed on the recording medium.

Subsequently, the superimposed toner image transferred onto the recording medium is heated and fixed. This image fixing step can be performed using various heating means. Suitable fixing methods include, for example, a hot roll fixing method, a flash fixing method, and an oven fixing method. In carrying out the present invention, in addition to the above-described various apparatuses, well-known apparatuses required for performing the electrophotographic process, that is, a cleaning apparatus, a static elimination apparatus, and the like can be used. These devices are well known to those skilled in the art and need not be described in detail here.

The image forming method and apparatus according to the present invention will be further described. FIG. 9 is a sectional view of an image forming apparatus using the toner layer thickness regulating blade according to the present invention.
In the figure, reference numeral 1 denotes an OPC photosensitive drum (diameter 30).
mm), and rotates in the direction of arrow A at a peripheral speed of 57 mm / s. The pre-charging is performed using the rotating brush 13, and the surface potential of the photosensitive drum 1 is charged to -650V. The print information is formed in the form of a latent image by irradiating the photosensitive drum 1 with light according to the information by a laser scanning optical system (not shown). Next, the formed latent image is visualized by the non-magnetic one-component developing device 6.

As shown, the non-magnetic one-component developing device 6 includes a developing roller 2, a toner supply / recovery roller 3, a toner (not shown) contained in a developing device frame 6a, and a toner layer having a charging function. Thickness regulating blade 5, agitator 7,
It comprises a paddle 8, a toner bottle 9, and an outer 10. In the developing section, a developing roller 2 in contact with the photosensitive drum 1
Is rotated in the same direction at twice the peripheral speed of the photosensitive drum,
The supplied toner is formed into a thin layer toner by the blade 5 and adhered to the latent image portion of the photosensitive drum 1 to form a visualized image. The toner that has not contributed to the development is scraped off by the roller 3 rotating in the opposite direction below the developing roller 2 and returned to the developing device 6 through the lower part of the roller 3.

On the other hand, new toner is supplied to the developing roller 2 by the rotation of the roller 3 and is carried to the blade 5, and a thin layer toner having a specified layer thickness is formed on the surface of the developing roller 2 by the blade 5. The replenishment of the toner is performed by transporting the toner swept out of the toner bottle 9 by the outer 10 to the developing roller 4 while being stirred by the agitator 7. The paddle 8 can efficiently supply the toner to the roller 3.

The toner adhering to the photosensitive drum 1 is attracted to the paper 21 by the transfer roller 11 at the transfer section, is melted by the fixing device 12, and is fixed on the paper. The paper 21 is supplied from the paper hopper 20. FIG.
9 shows the developing section of the image forming apparatus shown in FIG. 9 taken out, and arrows A, B, and C indicate the rotation directions of the photosensitive drum 1, the developing roller 2, and the roller 3, respectively. As shown in the drawing, a developing roller 2 rotating in the direction of arrow B is disposed close to or in contact with a roller-shaped photosensitive drum 1 rotating in the direction of arrow A. The roller 3 is arranged in contact with the rotating roller 3. Between the photosensitive drum 1 and the roller 3, a toner layer thickness regulating blade 5 according to the present invention is pressed against the surface of the developing roller 2 so that the tip of the blade 5 faces and slides in the rotation direction B of the developing roller 2. It is arranged. The attachment of the blade 5 will be described. The blade 5 is attached to a holder 6b made of an insulating resin by a pressing plate 6c.
And a screw 6d, and the holder 6b is fixed to the developing device frame 6a using a screw 6e.

In the configuration of the developing section as shown in FIG. 10, an applied voltage of -420 V
Is applied with an applied voltage of -320V. The toner 4 carried by the rotation of the roller 3 is charged by charge injection and frictional charging with the developing roller 2 rotating in contact with the roller 3, and adheres to the surface of the developing roller 2. The toner 4 adhering to the developing roller 2 is further frictionally charged by the blade 5 and the developing roller 2 by pressurizing friction and charge injection by the rotation of the developing roller 2, and is uniformly charged to a uniform thickness. Layers are formed and passed through. Then, the developing roller 2 and the photosensitive drum 1 are conveyed to a developing area where the developing roller 2 and the photosensitive drum 1 are close to each other or in contact with each other.

Next, a part of the toner 4 on the developing roller 2 adheres to the electrostatic latent image portion on the photosensitive drum 1 to visualize the electrostatic latent image. The remaining toner that has not contributed to the visualization of the latent image returns to the roller 3 as the developing roller 2 rotates. Further, the residual toner 4 on the developing roller 2
Is scraped off by the roller 3, but most of the toner 4
Pass through the contact portion with the roller 3 only by being disturbed without being scraped off.

The above operation is repeated to complete the developing step of the method and apparatus of the present invention. Here, the toner layer thickness regulating blade 5 which is one of the features of the present invention will be further described with reference to FIG. 11. The size of the blade 5 is, for example, L1 = 16 ± 4 mm and L2 = 1 ± 0.2 mm. , H1 = 2
It is preferable to set the relationship such as 0 ± 10 μm and h2 = 40 ± 10 μm. here,
As described above with reference to FIG. 6, h1 is the amount of chamfer in the thickness direction of the blade, and h2 is the amount of chamfer in the width direction of the blade.

FIG. 12 is a sectional view of a tandem type color image forming apparatus using the toner layer thickness regulating blade according to the present invention. As shown in the figure, image forming units 30, 40, 80, and 90 that form yellow, magenta, cyan, and black monochromatic images, respectively,
It is arranged in one transport direction (see arrow). Each of the image forming units includes a photosensitive drum serving as an image carrier as a center, a charging device for putting a charge on the surface of the photosensitive drum, an exposure device for forming a latent image, and a toner for visualizing the latent image with a developer. A developing device for forming an image; a transfer device for transferring the visualized toner image to a sheet of image recording medium; a static eliminator for removing electric charges remaining on the surface of the photosensitive drum; And a cleaning device for removing transfer residual toner remaining in the image forming apparatus. For example, the yellow image forming unit 30 includes a conductive brush charger 32 around the photosensitive drum 31,
Exposure device 33, developing device 34, image transfer device 35
, A static eliminator 36, and a cleaning device 37. Further, the magenta image forming unit 40, the cyan image forming unit 80, and the black image forming unit 90
Each of them has the same configuration as the yellow image forming unit 30 as shown in the figure. Further, the transfer belt 71 is a semiconductive dielectric belt that can move in the direction of the arrow, and can convey the paper 21 by electrostatically attracting it. The toner image composed of yellow, magenta, cyan, and black is melted and pressed on the paper 21 by the image fixing device 12,
Complete the desired full-color image.

In the practice of the method of the present invention, the developer used for visualizing the electrostatic latent image is a non-magnetic one-component developer. As described above, the present inventors have found that when this developer is used under specific conditions, the action and effect unique to the present invention can be sufficiently exhibited. In addition, since the nonmagnetic one-component developer does not require the use of a carrier, a device such as mixing and stirring of the toner is not required, which is preferable in that the size of the developing device can be reduced. Further, in the case of this developer, it is not necessary to mix a magnetic material into the toner, and since the transparency is high and the toner can be made thinner, the developer can exert its effect in forming a full-color image. This one-component developer can basically have the same composition as a conventionally used one-component developer, and can be prepared according to a similar technique. However, in the present invention, it is needless to say that it is necessary to control the particle size and thermal characteristics of the developer based on the above-mentioned guidelines.

The binder resin serving as a main component of the one-component developer (hereinafter also referred to as “developer” or “toner”) includes various resin materials. Suitable binder resins include, but are not limited to, those listed below, such as polyol resins, polystyrene, poly-p-chlorostyrene, polymers of substituted styrenes such as polyvinyltoluene, and styrene-p-chloroform. Styrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate Copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene -Α-chloromethyl methacrylate copolymer, Styrene - acrylonitrile copolymer, styrene - vinyl ethyl ether copolymer, styrene - vinyl methyl ketone copolymer, styrene - butadiene copolymer, styrene -
Styrene-based copolymers such as isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, Polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin,
Epoxy polyol resin, polyurethane, polyamide,
Polyvinyl butyral, polyacrylic acid resin, rosin,
Modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax and the like can be mentioned. These binder resins may be used alone or
More than one kind may be mixed and used.

Colorants can also be used as a developer component. As the colorant, all known dyes and pigments generally used in developers can be used. Suitable coloring agents include, for example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, loess, graphite, titanium yellow, poly Azo yellow, oil yellow, Hansa yellow (GR, A, RN, R),
Pigment Yellow L, Benzidine Yellow (G, G
R), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Tan, Lead Zhu, Cadmium Red, Cadmium Mercury Red , Antimony Vermilion, Permanent Red 4R, Para Red, Phisaed Red, Para Chloro Ortho Nitroaniline Red,
Risor fast scarlet G, brilliant fast scarlet, brilliant kahnmin BS, permanent red (F2R, F4R, FRL, FRLL, F
4RH), Fast Scarlet VD, Belcan Fast Rubin B, Brilliant Scarlet G, Lisor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5
B, Toluidine Maroon, Permanent Bordeaux F2
K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Museum, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thio Indigo Maroon,
Oil red, quinacridone red, pyrazolone red, polyazo red, chrome vermillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue lake, peacock blue lake, victoria blue lake, metal-free phthalocyanine blue, phthalocyanine blue , Fast Sky Blue, Indanthrene Blue (R
S, BC), indigo, ultramarine, navy blue, anthraquinone blue, fast violet B, methyl violet lake, cobalt violet, manganese violet, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B, naphthol green B, green gold, acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, lithobon, and the like. These colorants may be used alone or in combination of two or more.
Although the amount of the colorant used can be changed in a wide range depending on the type of the developer to which the colorant is added, the desired effect, and the like, it is generally 0.1 to 50 parts by weight based on 100 parts by weight of the binder resin. It is in the range of parts by weight.

In the practice of the method of the present invention, the toner of a plurality of colors used for forming a color image may be of any color, but it is preferable to be able to reproduce full color. Further, it is preferable that the toners of a plurality of colors other than black be three colors of yellow, cyan and magenta, since the number of developments can be reduced and a relatively wide color tone range can be covered.

The developer of the present invention may contain a charge controlling agent, if necessary. As the charge control agent, any of commonly used known developers can be used. Examples of suitable charge control agents include, but are not limited to, those listed below, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy dyes Amine amine, 4
Examples include quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkyl amides, simple substances or compounds of phosphorus, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. More specifically, such a charge controlling agent is, for example, a nigrosine dye “Bontron 0”
3 ", the quaternary ammonium salt" Bontron P-5 "
1 ", metal-containing azo dye" Bontron S-34 ", oxynaphthoic acid-based metal complex" E-82 ", salicylic acid-based metal complex" E-84 ", and phenol-based condensate" E-
89 "(both manufactured by Orient Chemical Industries)," TP-302 "and" T
P-415 "(above, manufactured by Hodogaya Chemical Industry Co., Ltd.) and" copy charge SPY VP203 of quaternary ammonium salt.
8 ”,“ copy blue P ”of a triphenylmethane derivative
R "," copy charge NEG of quaternary ammonium salt "
VP2036 "or" Copy Charge NX VP43 "
4 "(above, manufactured by Hoechst) and the boron complex" LR "
A-901 "and" LR-147 "(all manufactured by Nippon Carlit Co., Ltd.), copper phthalocyanine pigments, perylene pigments, quinacridone pigments, azo pigments, and other functionalities such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts. And high molecular compounds having a group. These charge control agents may be used alone or in combination of two or more.

The amount of the charge control agent used in the developer is
It is determined by the toner manufacturing method including the type of the binder resin, the presence or absence of additives used as necessary, and the dispersion method, and is not limited to a specific one. 0.1 to
The range is 10 parts by weight. The use amount of the charge control agent is more preferably in the range of 2 to 5 parts by weight. If the amount of the charge control agent is less than 0.1 part by weight, the negative charge of the toner is insufficient, which is not practical. On the other hand, when the amount of the charge control agent used is 10
When the amount exceeds the weight part, the chargeability of the obtained toner becomes too large, and the image density is reduced due to spent or filming due to an increase in electrostatic attraction with the developing roller or the like.

In the developer used in the present invention, it is preferable that a wax is contained in the produced developer in order to give the developer a releasability. The wax suitable for imparting releasability has a melting point in the range of 40 to 120 ° C, particularly preferably a melting point in the range of 50 to 110 ° C. If the melting point of the wax is too high, the fixability at low temperatures may be insufficient. On the other hand, if the melting point is too low, the offset resistance and durability may decrease.
The melting point of the wax is determined by a differential scanning calorimetry (DS
C). That is, the melting peak value when a few mg of sample is heated at a constant heating rate, for example (10 ° C./min), is defined as the melting point.

The wax which can be used in the developer of the present invention is not limited to those listed below. For example, solid paraffin wax,
Micro wax, rice wax, fatty acid amide wax, fatty acid wax, aliphatic monoketones, fatty acid metal salt wax, fatty acid ester wax, partially saponified fatty acid ester wax, silicone varnish,
Higher alcohols, carnauba wax and the like can be mentioned. Polyolefins such as low molecular weight polyethylene and polypropylene can also be used as waxes. In particular, the softening point (according to the ring and ball method) is 70 to 15
A polyolefin wax having a softening point in the range of 0 ° C is more preferable, and a polyolefin wax having a softening point in the range of 120 to 150 ° C is more preferable. These waxes may be used alone or as a mixture of two or more.

The developer used in the present invention can be prepared by mixing the above constituent materials according to a conventional technique. For example, in producing black and a plurality of toners, after mixing the above-described constituent materials with a mixer such as a Henschel mixer, and kneading with a kneader such as a continuous kneader or a roll kneader,
After cooling and solidifying the kneaded material, a method of pulverizing and classifying to obtain a desired particle size distribution is preferable. Other preparation methods include spray drying, polymerization, and microcapsule methods. Further, the toner thus obtained can be sufficiently mixed with a suitable external additive by a mixer such as a Henschel mixer, if necessary, to finally obtain a target toner.

In the developer used in the present invention, an external additive may be further added to the toner prepared as described above. The external additive used here may be basically any external additive commonly used in this technical field. Suitable external additives include, for example, inorganic fine particles. The primary particle diameter of the inorganic fine particles used as the external additive is usually preferably from 0.005 to 2 μm, and particularly preferably from 0.005 to 0.5 μm. The specific surface area of such inorganic fine particles is 20 to 500 m ² / g when measured by the BET method.
Is preferably within the range. The usage ratio of the inorganic fine particles is 0.01 to 5.0 based on the total amount of the toner.
It is preferably in the range of 0% by mass (wt%), and more preferably in the range of 0.01 to 2.0% by mass.
Specific examples of suitable inorganic fine particles include, for example, fatty acid metal salts and metal oxides such as silica, alumina (aluminum oxide), titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, Zinc stearate, aluminum stearate, zinc oxide, tin oxide, silica sand, clay, mica,
Examples include wollastonite, diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, and the like.

Suitable external additives include, in addition to the inorganic fine particles described above, polymer fine particles, that is, resin fine particles, for example, polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, or dispersion polymerization, Examples thereof include polymer particles of a methacrylate or acrylate copolymer, a polycondensation system such as silicone, benzoguanamine, or nylon, or a thermosetting resin.

Among the above-mentioned external additives, hydrophobic silica, titania and alumina fine particles are particularly preferable. To explain these fine particles specifically, silica fine particles include “HDK H200
0 ”,“ HDK H 2000/4 ”,“ HDK H
2050EP "," HVK21 ", etc. (trade names, all manufactured by Clariant)," R972 "," R97
4 "," RX200 "," RY200 "," R20 "
2 "," R805 ", and" R812 "(trade names, all manufactured by Nippon Aerosil Co., Ltd.).

As the titania fine particles, “P-2
5 ”(trade name, manufactured by Nippon Aerosil Co., Ltd.) and“ STT
-30 "," STT-65CS "(trade name, manufactured by Titanium Industry Co., Ltd.)," TAF-140 "(trade name, manufactured by Fuji Titanium Co., Ltd.)," MT-150W "," MT-50 "
0B "and" MT-600B "(trade name, manufactured by Teica).

Particularly, as the titanium oxide fine particles subjected to the hydrophobic treatment, anatase-type or rutile-type crystalline or non-crystalline titanium oxide fine particles can be used. Such fine particles are commercially available, for example, under the following trade names: “T-805” (manufactured by Nippon Aerosil Co., Ltd.), “MT-
100S "," MT-100T "," MT150A "and" MT150AFM "(manufactured by Teica)," STT-3 "
0A "and" STT-65S-S "(manufactured by Titanium Industry Co., Ltd.)," TAF-500T "and" TAF-1500 ".
T "(manufactured by Fuji Titanium Co., Ltd.)," MT-100S "and" MT-100T "(manufactured by Teica)," IT-S "(manufactured by Ishihara Sangyo).

In order to obtain hydrophobized silica fine particles, tania fine particles or alumina fine particles, hydrophilic fine particles are treated with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane or octyltrimethoxysilane. Can be obtained. In addition, the above-mentioned external additives include a fluidizing agent (or a surface treatment agent).
Is also useful. Such a surface treating agent increases the hydrophobicity of the toner by performing a surface treatment on the toner, and can prevent the flow characteristics and the charging characteristics from being deteriorated even under high humidity. For example, a silane coupling agent, a silylating agent, a silane coupling agent having a fluorinated alkyl group, an organic titanate-based coupling agent, an aluminum-based coupling agent, and the like are preferable surface treatment agents.

Further, a cleaning improver is also useful as an external additive. The cleaning property improving agent has a property of removing the developer after transfer remaining on the photosensitive drum and the primary transfer medium, that is, a function of improving the cleaning property. Suitable cleanability improvers include, for example, fatty acid metal salts such as zinc stearate, calcium stearate, and sodium stearate; for example, polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles; and the like. Can be mentioned. Here, the polymer fine particles used as the cleaning property improver have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.
Those included in the range of m are preferred.

[0062]

Next, the present invention will be described with reference to examples. It should be understood that the present invention is not limited to the following examples. Measurement of Glass Transition Point (Tg) The Tg (° C.) of the toner was measured by the following procedure using “DSC-200” manufactured by Seiko Denshi.

1. The sample is pulverized, weighing 10 ± 1 mg into an aluminum sample container, and the aluminum lid is crimped from above. 2. Glass transition point (T
g) is measured. Here, the sample is heated from room temperature to a heating rate of 2
After heating to 150 ° C. at 0 ° C./min, it is left at 150 ° C. for 10 minutes. Further, this sample was cooled to 0 ° C. at a temperature lowering rate of 50 ° C./min and left for 10 minutes.
/ Min. After the heating is completed, a DSC measurement is performed. Measurement of Weight Average Particle Size and Particle Size Distribution The weight average particle size and particle size distribution of each toner were measured at an aperture diameter of 100 μm using a Coulter Counter TAII manufactured by Coulter Corporation. Example 1 Preparation of Toners A to G (1) Preparation of Toner A Styrene-butyl acrylate copolymer 85 parts by weight (styrene / n-BA = 82/18, Mn = 7400, Mw / Mn = 39, Tg = 63 ° C.) Carbon black (MA60, manufactured by Mitsubishi Chemical Corporation) 10 parts by weight Chromium-containing azo dye (Bontron S34, manufactured by Orient Chemical Company) 3 parts by weight Carnauba wax (ester wax, melting point = about 82 ° C.) 2 parts by weight After mixing with a mixer, the mixture was melt-kneaded with a twin-screw extruder and the obtained kneaded product was rolled and cooled. Thereafter, the kneaded material was subjected to pulverization classification, and the weight average particle size was 9.1 μm.
Was obtained. Next, hydrophobic silica (HDK2000H, manufactured by Clariant) was added to the obtained toner in an amount of 0.5% by mass (wt%) and mixed with a mixer. The Tg of the toner A thus obtained was 62 ° C.
The amount of fine powder having a weight average particle size of 5 μm or less was 16% by number. (2) Preparation of Toner B Polyester resin 1 700 parts by weight (acid value = 5, Mn = 4500, Mw / Mn = 4.0, Tg = 65 ° C.) Blue pigment 300 parts by weight (LIONOL BLUE FG-7351, Toyo Ink) Mix the above materials well with a Henschel mixer and mix
Three passes were kneaded with this roll. After completion of kneading, the obtained kneaded material was cooled and pulverized with a pulperizer. In the next step, a master batch pigment used for preparing a toner was obtained.

100 parts by weight of polyester resin 2 (acid value = 5, Mn = 45000, Mw / Mn = 4.0, Tg = 60 ° C.) master batch pigment (prepared as described above) 10 parts by weight zinc salicylate derivative ( Bontron E84, 4 parts by weight, manufactured by Orient Chemical Co.) After mixing the above materials with a mixer, a twin screw extruder
And the resulting kneaded product was rolled and cooled. That
Thereafter, the kneaded material was subjected to pulverization classification, and the volume average particle size was 8.4 μm.
Was obtained. Next, the obtained toner is hydrophobic.
Silica (HDK2000H, Clariant)
0.5 wt% was added and mixed with a mixer. This
The thus obtained toner B has a Tg of 59 ° C. and a weight average particle size of
The amount of fine powder having a diameter of 5 μm or less was 12% by number. (3) Preparation of Toner C The preparation of the toner A was repeated.
The average particle size is 11.5 μm and the amount of fine powder of 5 μm or less
The preparation conditions were changed to be 11% by number. Got
The toner is referred to as “toner C”. (4) Preparation of Toner D The preparation of the toner A was repeated.
The average particle size is 7.3 μm, and the amount of fine powder of 5 μm or less is 2
The preparation conditions were changed so as to be 3% by number. Obtained
The toner is “toner D”. (5) Preparation of Toner E The preparation of the toner A was repeated.
The average particle size is 5.7 μm, and the amount of fine powder of 5 μm or less is 1
The preparation conditions were changed to 9% by number. Obtained
The toner is “toner E”. (6) Preparation of Toner F The preparation of Toner B was repeated.
Polyester resin 3 (Mn =
4700, Mw / Mn = 2.4, Tg = 54 ° C.)
Used in. The Tg of the toner F thus obtained is
54 ° C., the weight average particle size is 8.6 μm, and the weight average particle size is 5
The amount of fine powder having a particle size of μm or less was 9% by number. (7) Preparation of Toner G The preparation of toner B was repeated.
Polyester resin 4 (Mn =
6100, Mw / Mn = 7.6, Tg = 71 ° C.)
Used in. The Tg of the toner G thus obtained is
71 ° C., weight average particle size 8.5 μm, weight average particle size 5
The amount of fine powder having a particle size of μm or less was 8% by number. Example 2 Evaluation Test of Toner (1) The toners A to G prepared in Example 1 were described with reference to FIG.
Installed in the image forming apparatus described, print quality, OHP
Regarding permeability and generation of white stripes (generation of blade fusion)
The evaluation test was conducted visually. Note that the non-
The toner layer thickness regulating blade of the magnetic one-component developer is flat
Made of spring stainless steel with a chamfered tip at
And the shape is the same as the blade of FIG.
It is. The results of the obtained evaluation test are shown in Table 1 below.
You.

[0065]

[Table 1]

In the evaluation results shown in Table 1 above,
Indicates that it is acceptable to judge it visually, and x indicates that it is not acceptable to judge it visually. Evaluation Test of Toner (2) Regarding the toner C prepared in Example 1, the relationship between the particle size of the toner and the thickening of characters / thin lines was investigated.
Was obtained. As is apparent from the figure, thickening of the character / thin line occurs when the toner particle size is 10 μm or more. Evaluation Test of Toner (3) For the toners D and E prepared in Example 1, the relationship between the particle size of the toner and the content of the toner fine powder was investigated.
The result plotted in FIG. 14 was obtained. It was found that fusion of the blade occurred at the hatched portions in the figure, and that with these toners, the toner was fused to the blade and "white streaks" were generated. Evaluation Test of Toner (4) With respect to the toners F and G prepared in Example 1, the relationship between the glass transition point and the transmittance of the toner was examined, and the results plotted in FIG. 15 were obtained. At the hatched portions in the figure, the blade is fused, and with these toners, the toner is fused to the blade to generate "white streaks" and O
It was found that HP permeability was poor.

[0067]

As described above, according to the present invention, the thermal characteristics of the toner are regulated, the fine powder content of the toner is reduced, the blade is formed of a flat metal elastic member, and the tip of the blade is formed. By performing chamfering on the toner layer, it is possible to provide a toner layer thickness regulating blade which is extremely simple to manufacture, and which can obtain high quality and high reliability printing, and an image forming apparatus. Further, the image forming apparatus of the present invention can be advantageously used particularly for forming a color toner image.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a developing device including a conventional toner layer thickness regulating blade.

FIG. 2 is a cross-sectional view showing another example of a developing device provided with a conventional toner layer thickness regulating blade.

FIG. 3 is a cross-sectional view showing another example of a developing device provided with a conventional toner layer thickness regulating blade.

FIG. 4 is a sectional view showing still another example of a developing device provided with a conventional toner layer thickness regulating blade.

FIG. 5 is a sectional view showing still another example of a developing device provided with a conventional toner layer thickness regulating blade.

FIG. 6 is a cross-sectional view showing an example in which the toner layer thickness regulating blade of the present invention is used in a developing device.

FIG. 7 is a sectional view showing another example in which the toner layer thickness regulating blade of the present invention is used in a developing device.

FIG. 8 is a sectional view showing still another example in which the toner layer thickness regulating blade of the present invention is used in a developing device.

FIG. 9 is a cross-sectional view illustrating an example of an image forming apparatus using the toner layer thickness regulating blade of the present invention.

FIG. 10 is a sectional view illustrating a developing unit of the image forming apparatus of FIG. 9;

FIG. 11 is a cross-sectional view showing a state in which the toner layer thickness regulating blade of the present invention is pressed against a developing roller.

FIG. 12 is a cross-sectional view illustrating an example of a tandem type color image forming apparatus using the toner layer thickness regulating blade of the present invention.

FIG. 13 is a graph in which the relationship between the particle size of the toner and the thickness of the character / thin line is plotted.

FIG. 14 is a graph in which the relationship between the particle size of the toner and the content of the toner fine powder is plotted together with the blade fusion generation region.

FIG. 15 is a graph in which the relationship between the glass transition point and the transmittance of the toner is plotted together with the blade fusion generation region.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photosensitive drum 2 developing roller 3 toner supply and collection roller 4 toner 5 toner layer thickness regulating blade 6 non-magnetic one-component developing device 7 agitator 8 paddle 9 toner bottle 10 outer 11 transfer roller 12 ... Fusing unit 20 ... Paper hopper 21 ... Paper

Continuation of the front page (72) Inventor Takashi Yamamoto 4-1-1, Uedanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (72) Masae Nakamura 4-1-1, Kamikodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture No. Within Fujitsu Limited (72) Inventor Yoshimichi Katagiri 4-1-1 Kamikadanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Within Fujitsu Limited (72) Shinichi Kuramoto 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Hachiro Tosaka 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Hiroshi Yamashita 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Osamu Uchinokura 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Kazuhiko Hamazoe 35th Saho, Shatocho, Kato-gun, Hyogo Prefecture Reference) 2H005 AA21 CA21 EA03 EA05 FA07 2H030 AD01 BB23 BB24 2H077 AD06 AD13 AD17 AD23 AD31 AE03 AE04 EA14 EA15 FA01 GA13

Claims (4)

[Claims] 1. An image forming method for forming a color image in accordance with an electrophotographic method using a contact-type non-magnetic one-component developing device, wherein the developing device comprises a metal elastic member as a toner layer thickness regulating blade. A flat blade having a chamfered tip is used, and the toner has a glass transition point of 55 to 70 ° C., a weight average particle diameter of 6.0 to 10.0 μm, and
An image forming method, comprising using a developer having 20% by number or less of particles having a particle diameter of not more than μm. 2. An image forming apparatus provided with a contact-type non-magnetic one-component developing device for forming a color image according to an electrophotographic method, wherein the developing device regulates a thickness of a developer layer on a developing roller mounted thereon. As the toner layer thickness regulating blade, a flat blade made of a metal elastic member and having a chamfered tip is provided, and the developer accommodated in the developing device has a toner glass transition point of 55 to 55. 70 ° C., the weight average particle size is 6.0 to 10.0 μm,
An image forming apparatus, wherein the developer has 20% by number or less of particles having a particle size of not more than μm. 3. When the surface roughness of the chamfered portion of the toner layer thickness regulating blade is 1 mm,
The image forming apparatus according to claim 2, wherein the thickness is not more than μm. 4. When the chamfered portion of the toner layer thickness regulating blade has a chamfer amount h1 in a thickness direction of the blade and h2 in a width direction of the blade, the following relationship is satisfied: 1 ≦ h2 / The image forming apparatus according to claim 2, wherein h1 ≦ 5 is satisfied.