JPH0240672A - Developing device - Google Patents

Abstract

PURPOSE:To restrain toner spilling over an image carrier side by providing a guide member with a toner restraining part so as to project from the side edge part of a toner regulating member to inside thereof. CONSTITUTION:The developing device 1 is provided with the toner restraining part 12a projecting from the side edge part of a blade 13a to the inside; the length of the part 12a covers the tip part of the blade 13a which press-contacts the surface of a toner carrying member 10 to the toner carrying side. The toner supplied to both sides of the surface of carrying member 10 is restrained by the restraining part 12a and restrained not to spill over the side of a photosensitive drum 2 through a space S between the blade 13a and the guide member 12.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a developing device used in an electrophotographic device, etc., and particularly to a developing device that prevents toner supplied to the surface of a toner carrier from flowing out to the image carrier side. It is characterized by the fact that it suppresses

[Prior art and its problems] Conventionally, in a developing device using a -component developer,
As disclosed in Japanese Patent Application Laid-Open No. 52-143831, non-magnetic toner is supplied to the surface of an elastic roller that conveys the toner, and this toner is pressed against the surface of the elastic roller by a toner regulating member such as a blade. , which charges the toner and regulates the thickness of the toner layer on the surface of the elastic roller.

Then, the surface of the elastic roller on which the toner layer of the required thickness has been formed is brought into contact with the surface of an image carrier such as a photoreceptor drum, and the toner is applied to the latent image portion formed on the surface of the image carrier. It is supposed to be done.

In such a developing device, a toner regulating member such as a blade is brought into pressure contact with the surface of the elastic roller to charge the toner, so the surface of the elastic roller is required to have relatively high hardness. In order to supply toner by bringing the surface of the roller into contact with the surface of the image carrier, it is necessary to bring the surface of the elastic roller into soft contact with the surface of the image carrier throughout its axial direction.

However, as mentioned above, it is very difficult to bring the surface of the elastic roller, which has relatively high hardness, into soft contact with the surface of the image carrier over the entire axial direction, which may damage the image carrier or cause damage to the image carrier. There were problems such as a decline in image quality.

For this reason, in a previous application, the present applicant installed a toner conveying member (10) with a larger diameter than the drive roller (9) with guides provided on both sides of the toner conveying member (10), as shown in FIGS. 1 and 2. The member (12) is brought into pressure contact with the driving roller (9) except for the facing part that faces the image carrier (2), and in the facing part, the toner conveying member (10) is held by the driving roller (9). The toner conveying member (10) is brought into soft contact with the surface of the photoreceptor drum (2), which is the image carrier (2), to transfer the toner (4) to the photoreceptor drum (2). A developing device (1) has been disclosed which is adapted to apply the image to the surface of a drum (2).

In such a developing device (1), toner (4) is supplied from the toner storage tank 3) to the surface of the toner conveying member (10), and a small diameter presser rod (1) is attached to the tip of the blade (13a). The toner regulating member (13b) provided with the toner regulating member (13b)
3), the supplied toner (4) is brought into pressure contact with the surface of the toner conveying member (10).

Here, when providing the above-mentioned toner regulating member (13), the toner regulating member (13) is prevented from coming into contact with the guide members (12) provided on both sides of the toner conveying member (10). Therefore, as shown in FIG. 7, a gap (S) is provided between the toner regulating member (13) and the guide member (12).

However, when a gap is provided between the toner regulating member (13) and the guide member (12) in this way, the toner (4) supplied to the surface of the toner conveying member (10) is A problem arose in that the liquid spilled through the image carrier (2> side).

For this reason, in the past, an elastic material such as Moltoprene (not shown) was pasted in the gap (S) between the toner regulating member (13) and the guide member (12). Depending on the method of attachment, there is a problem in that the charging of the toner (4) by the toner regulating member (13) and the regulation of the thickness of the toner layer are adversely affected.

[Problems to be Solved by the Invention] The present invention has been made with an object of solving the above-mentioned problems.

That is, in the present invention, a toner conveying member having a diameter larger than that of the driving roller is made to protrude toward the image bearing body from the driving roller at the facing portion facing the image bearing member, and this protruding toner conveying member is connected to the image bearing member. In a developing device that applies toner by making soft contact with the surface of the image carrier, it is possible to prevent toner from spilling onto the image carrier side without adversely affecting toner charging by the toner regulating member or regulating the thickness of the toner layer. The purpose is to do so.

[Means for Solving the Problems] In the developing device according to the present invention, the drive roller is covered with a toner transport member having a diameter larger than that of the drive roller, and guide members are provided on both sides of the toner transport member, With this guide member, the toner conveying member is caused to protrude toward the image bearing body from the driving roller at the facing portion facing the image bearing member, and the toner conveying member is brought into pressure contact with the driving roller at a portion other than the facing portion. There is.

Then, a toner regulating member that regulates the thickness of the toner layer is brought into pressure contact with the surface of the toner conveying member that is pressed against the drive roller as described above, and at a position on the toner feeding side of the toner regulating member, the toner conveying member Each guide member provided on both sides of the toner regulating member is provided with a toner suppressing portion that projects inward from the side end portion of the toner regulating member.

Note that the toner suppressing portion provided on the guide member is desirably formed in a shape that inclines and protrudes inward toward the toner regulating member.

[Function] In the developing device configured as described above, since the toner suppressing portion is provided in the guide member so as to protrude inward from the side end portion of the toner regulating member, the toner supplied to the surface of the toner conveying member is The toner suppressing portion suppresses toner from spilling out to the image carrier side through the gap between the toner regulating member and the guide member.

Further, since the toner suppressing portion is provided at a position on the toner feeding side of the toner regulating member and apart from the toner regulating member, it does not have any adverse effect on toner charging or toner thickness regulation by the toner regulating member.

Furthermore, if the toner suppressing section is formed in a shape that inclines inwardly and protrudes toward the toner regulating member, the toner suppressing section allows the toner supplied to both sides of the toner conveying member to be sent to the center. As a result, toner is less likely to accumulate and remain in the toner suppressing portion.

[Example] Hereinafter, an example of the present invention will be specifically described based on the drawings.

As shown in FIG. 1, the developing device (1) in this embodiment is provided at a position close to the photoreceptor drum (2), which is the image carrier (2), and is connected to the photoreceptor drum (2). A toner storage tank (3) is provided at a remote rear position, and toner (3), which is a one-component developer, is stored in this toner storage tank (3).
4) is accommodated.

Here, as shown in the figure, the toner storage tank (3) has a large first agitating portion located at the rear, away from the photoreceptor drum (2), by a mountain portion (3a) provided at the bottom of the toner storage tank (3). (5) and a small second stirring section (6) located closer to the photoreceptor drum (2) than the first stirring section (5). Part (5), (
6) is provided with first and second stirring members (7) and (8) that stir the toner (4), respectively.

Then, the first stirring member (7) provided in the first stirring part (5) is rotated to stir the toner (4) in the first stirring part (5), and the toner (4) is stirred in the second stirring part (5). Stirring part (6)
It is supposed to be sent to

Further, the toner (4) thus sent to the second stirring section 6) is further rotated by the rotation of the second stirring member (8) provided in the second stirring section (6). It is designed to be stirred.

The photoreceptor drum (2) is then accessed from the toner storage tank (3).
) side is provided with a toner conveying member (10) driven by a drive roller (9), and the toner (4) stirred in the second agitating section (6) is transferred to the toner conveying member (10). It is adapted to be supplied to the surface of the member (10) by contact or electrostatic force.

Here, the drive roller (9) may be one made of a conductive member such as aluminum or stainless steel, or one made of a conductive material such as aluminum or stainless steel, or a base body formed in a cylindrical shape with a conductive layer or a conductive rubber layer provided on the outer peripheral surface. things etc. are used.

This driving roller (9) is connected to the photosensitive drum (2).
The developing device (1) is rotatably mounted to face the photoreceptor drum (2) in the vicinity of the opening (11) facing the developing device (1), and the photoreceptor drum (2) is rotated by a motor (not shown). It is designed to rotate in the opposite direction.

On the other hand, the toner conveying member (lO) is connected to the drive roller (9).
) is formed into a cylindrical shape having a diameter slightly longer than the outer diameter of the drive roller (9), and is provided so as to cover the outer periphery of the drive roller (9).

Further, guide members (12) are disposed on both sides of the toner conveying member (10) in the axial direction around the toner conveying member (10) except for the opening (11) and the vicinity thereof.

The guide member (12) allows the toner conveying member (10) to move around the facing portion facing the photoreceptor drum (2), that is, at a location other than the opening (11) of the developing device (1) and its vicinity. The toner conveying member (10) is pressed against the outer circumferential surface of the drive roller (9), and the toner conveying member (10) is driven by the frictional force thereof as the drive roller (9) rotates.

On the other hand, at the facing portion where the toner conveying member (10) faces the photoreceptor drum (2), the extra length of the toner conveying member (10), which is longer than the drive roller (9), is longer than the drive roller (9). This protruded toner conveying member (10) is protruded toward the photoreceptor drum (2).
) to apply the toner (4) to the surface of the photoreceptor drum (2) by sufficiently and softly contacting the surface of the photoreceptor drum (2).

In addition, in this developing device (1), as mentioned above, the toner conveying member (10) is supplied to the surface of the toner conveying member (10) at a portion that is in close contact with the drive roller (9>). As a toner regulating member (13) that presses the toner (4), a blade (13a) that is wider in the axial direction of the toner transport member (10) is attached above the toner transport member (10). ) is provided with a small diameter round rod (13b).

The small-diameter round rod (13b) provided at the tip of the blade (13a) in this way transfers the toner (4) supplied to the toner conveying member (10) onto the surface of the toner conveying member (10). The toner (4) is applied thinly and uniformly, and the toner (4) is triboelectrically charged.

In the developing device (1) according to this embodiment,
A blade (1) presses the surface of the toner conveying member (10).
At a position on the toner feeding side from the tip of the blade (13a), each guide member (12) provided on both sides of the toner conveying member (10) is provided with toner that protrudes inward from the side end of the blade (13a). A suppressing portion (12a) is provided.

In this way, each blade (1
The toner suppressing portion (12) protrudes inward from the side end of the
a), the toner (4) supplied to both sides of the surface of the toner conveying member (10) is transferred to the toner suppressing portion (1).
2a>, and spilling out to the photosensitive drum (2) side through the gap (S) between the blade (13a) and the guide member (12) is suppressed.

Here, the toner suppressing portion (1) provided on the guide member (12)
2a) may be anything that protrudes inward from the side end of the blade (13a), and its shape is not particularly limited. For example, as shown in FIG.
a) that partially protrudes from the tip of the blade (13) at a position on the toner feeding side, as shown in
The guide member (12) itself may be widened at the position on the toner feeding side from the tip of a), or the guide member (12) may be widened as it approaches the blade (13a), as shown in FIGS. It may also have an inclined and protruding shape.

In addition, as shown in FIGS. 5 and 6, the toner suppressing section (
12a) is formed to have a protruding shape that slopes inward as it approaches the blade (13a), the toner (4) supplied to both sides of the toner conveying member (10) is
The toner is sent to the center of the toner conveying member (10) along the edge of the toner suppressing portion (12a), and the toner (4) is prevented from accumulating and remaining in the toner suppressing portion (12a). Become so.

[Effects of the Invention] As described in detail above, the present invention allows the toner transport member to be moved closer to the image carrier than the drive roller at the facing portion facing the image carrier by the guide members provided on both sides of the toner transport member. In a developing device in which toner is applied by protruding and bringing the protruding toner conveying member into soft contact with the surface of an image bearing member, the toner regulating member that presses the toner into contact with the toner conveying member is located on the toner feeding side. In position,
The guide member is provided with an I/toner suppressing portion that protrudes inward from the side end portion of the toner regulating member, and the toner suppressing portion suppresses toner supplied to both sides of the surface of the toner conveying member. It is.

As a result, in this developing device, the toner supplied to both sides of the surface of the toner conveying member is prevented from spilling out to the image carrier side through the gap between the toner regulating member and the guide member. It became so.

In addition, since the toner suppressing portion is provided at a position on the toner feeding side of the toner regulating member and away from the toner regulating member as described above, the toner suppressing portion is provided separately from the toner regulating member, so that the toner There is no longer any negative effect on toner charging or toner layer thickness regulation by the regulating member.

Furthermore, when the toner suppressing section is formed in a shape that inclines inwardly and protrudes toward the toner regulating member, the toner supplied to both sides of the toner conveying member is removed along the toner suppressing section. is now sent to the center,
Toner no longer accumulates and remains in the toner suppressor.

[Brief explanation of the drawing]

1 is a schematic sectional view of the developing device, FIG. 2 is a partially enlarged sectional view of the developing device shown in FIG. 1, FIG. 3 shows an embodiment of the present invention, and a guide of the developing device shown in FIG. FIGS. 4 to 6 are plan views and perspective views showing other embodiments of the present invention, and FIG. 7 is a plan view showing a guide member provided with a toner suppressing portion. FIG. 3 is a plan view showing a state of a conventional developing device. (1)...Developing device, (2)...Image carrier (photosensitive drum), (4)...Toner, (9)...Drive roller. (10>... Toner conveying member, (12)... Guide member <12a)... Toner suppressing section, (13)...
・Toner regulating member, (13a)...blade, (
13b)...Round bar.

Claims (1)

[Claims] 1. The drive roller is covered with a toner conveyance member having a diameter larger than that of the drive roller, and guide members are provided on both sides of the toner conveyance member, and the guide members allow the toner conveyance member to face the image carrier. In a developing device in which the toner conveying member is made to protrude toward the image carrier side from the driving roller at a portion thereof, and the toner conveying member is brought into pressure contact with the driving roller at a portion other than the facing portion, on the surface of the toner conveying member that is in pressure contact with the driving roller, A toner regulating member that regulates the toner layer thickness is brought into pressure contact with the toner regulating member, and at a position on the toner feeding side of the toner regulating member, a guide member provided on both sides of the toner conveying member is pressed from the side end of the toner regulating member. A developing device characterized by being provided with a toner suppressing portion that protrudes inward.