JP2902332B2 - Printer unit in printing device and method of improving printing quality in printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has at least one printer unit, the printer unit is a printer unit of the printing device comprising at least one toner accommodating portion and the electrode unit for the toner particles, wherein electrode unit includes an electrode, as well as organic and an opening surrounded at least in part by the electrode, before
The toner storage section or the space that communicates with the toner storage section
The counter electrode and the toner key
To an information carrier that can be inserted between the carrier member and the counter electrode.
The transport of the toner particles is controlled by the attractive electric field
The toner carrier member, the electrode unit and / or the counter electrode may be an electrode unit and an information carrier.
A printer unit configured to form a toner particle transport zone between the two remotest electrodes in a relative direction to generate the attractive electric field, the attractive electric field attracting the toner particles to the counter electrode through the opening. About.

[0002]

BACKGROUND OF THE INVENTION U.S. Pat. No. 5,036,541 discloses a method for producing an image on an information carrier such as paper by means of an electrostatic field or by using an electrode unit between a toner carrier member such as a developing device and a counter electrode. And the device is known.

[0003] The electrode unit can be constructed as a woven mesh of mutually intersecting electrodes. The mesh is located between the electrodes, through which the toner particles are drawn from the toner carrier member toward the counter electrode.
By connecting the electrodes surrounding the mesh to different voltage sources, the passage of toner particles through the mesh is opened and closed.

[0004] The electrode unit can also be composed of a thin substrate having a transmissive opening surrounded by an electrode called a so-called annular electrode. Such electrodes are
It is disclosed in U.S. Pat. No. 5,121,144.

[0005] Another type of electrode unit is disclosed in British Patent No.
2 108 432, etc.
Two electrode layers are disposed on each side of the transporter, the electrodes surrounding the holes and conditioning particles from the toner carrier member through the holes to the counter electrode.

FIG. 1 shows SE9000031-6 or SE8704883-1
FIG. 1 is a schematic diagram of a printer unit 10 according to FIG. The toner particles 11 adhere to the toner carrier member 12 with a magnetic force or a similar force, and the toner carrier member 12
Is transported in the direction of the counter electrode 15 by an electrostatic field through the electrode unit. One of the conditions for transferring the toner particles 11 from the toner carrier member 12 to the information carrier to obtain good results is as follows.
First, the distance l _k between the toner carrier member 12 and the electrode unit 14 is very short, and the strength of the electric field for transporting the toner particles 11 is as strong as possible. Toner carrier member 12
The electric field between the carrier and the counter electrode 15 can be obtained by grounding the toner carrier member 12 and connecting the counter electrode to a 1.5 kV voltage source. By connecting the electrode 16 of the electrode unit 14 to a variable control voltage source Vc such as 300V, a passage through the opening 17 is created. By changing the size of such a passage, it is possible to allow the electric field to pass through the opening 17 partly or entirely, or not at all, so that the toner particles 11 are directed toward the counter electrode 15. It can be conveyed to an information carrier such as a paper sheet placed between the image carrier and the toner carrier member 12.

The toner carrier member 12 is rotatably disposed in the toner container (21), and
The toner particles are attracted by a magnet (not shown) or the like provided in the inside 2. The toner particles 11 attracted onto the toner carrier member 12
The toner carrier member 12 can be made of a conductive material or a semiconductive material.

The toner carrier member 12 is generally formed as a roller having an annular cross section,
Is formed substantially flat. Since this roller has an annular cylindrical shape, the distance l _k from the roller surface to the opening 17 varies. This fluctuation value and Δl _k. Regarding the distance of a vertical line (not shown) from the center of the roller to a point between the openings A2 and A3, the distance from the toner carrier member 12 to the openings A2 and A3 is the distance between the openings A1 and A3.
Shorter than the distance to 4.

[0009]

FIG. 2 is a schematic graph showing the relationship between the distance l _k and the electrostatic field E that attracts toner particles in the direction of the counter electrode 15. The variation value l _k changes the electrostatic field E, and also changes the number of toner particles attracted toward the surface of the information carrier 13. This change in the amount of toner particles affects print quality and causes undesirable changes in the resulting image. Further, a problem may occur in the case of printing in which colors are concentrated. This problem is called "White line noise" and is shown in FIGS.
As best shown in FIG. 1, the toner particles 11 of the toner carrier member 12
7, the lines of the image appear bright.

In FIG. 3, the arrow indicates the toner carrier member 12.
Shows the direction of rotation. For example, when the openings A1-A4 are opened in numerical order, a portion of the toner particles 18 is conveyed on the information carrier 13 in numerical order, and then the opening A1 receives the largest number of particles, while the subsequent openings The part receives progressively fewer particles. In the opening A4, the amount of toner is much smaller, and the print quality is degraded.

Another problem is that the toner particles "see" the conductive electrode 16 that attracts the toner particles as an electric field source. The lines indicated by dashed lines are A'1-A'4, B '
1, B ′ 2, which affects the toner particles on the toner carrier member 12. The shaded portions in the figure indicate how the toner particles are applied, ie, how they are conveyed to the information carrier 13. From the above figures, it is considered that B1 also affects the print area of A4.

[0012] Yet another problem is that the so-called "curtain effect" occurs, in which the black color, which was faint when starting to print a large area image,
Soon it will return to its normal density. This problem occurs when a plurality of adjacent electrodes 16 are applied simultaneously to produce a large area image. A plurality of adjacent applied conductors 19
The composite electric field generated by the plurality of adjacent electrodes 16 of
The toner particles are sufficiently strongly attracted from the toner carrier member 12 to the conductor 19. Due to such unevenness of the toner particles, the number of the toner particles fixed on the paper is reduced, and the blackness of the image is reduced. This spot of particles is quickly saturated, so that the rest of the image is given a normal black print. When the printing of the image portion is completed, the toner particles are transferred to the toner carrier member 12.
Pulled back up.

It is an object of the present invention to address the above mentioned obstacles, namely:
"White line noise"
It is to improve the print quality by eliminating the "curtain effect". Such a purpose is, the above-described toner
The chromatography particle conveying belt is divided into at least two narrow bands, in a space which communicates with the toner container or toner accommodating portion, and a plurality of toner carrier member that corresponds to the number of narrow-band, is constituted from the open mouth and the electrode Group of electrode units
It can be solved by the son-in-law.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to divide the above-described toner particle transport zone into at least two narrow bands ,
In the toner container or the space communicating with the toner container,
A plurality of toner carrier member that corresponds to the number of narrow-band, can be solved by including a group of electrode unit constructed from the open mouth and the electrode.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings showing some examples.

[0016] Example of the printer unit 10 shown in FIG. 4, the toner containing portion 21, communicating with the toner over housing section 21
And a casing 20 including a toner conveying section 22 formed as a space for forming the toner. The toner storage unit 21 includes the opening unit 2
4, the toner container 21 communicates with the lower toner transport unit 22 through the opening 24. A stirring blade 25 is disposed in the toner conveying unit 22, and the stirring blade 25 is directly or indirectly operated by a driving unit (not shown). A support member 26 is disposed on the toner conveying section 22. A scraping knife 27 which is a so-called doctor blade and a guide bar 28 are provided.
And At least two leveling rollers 29a and 29b are arranged at least in direct contact with toner containing members 12a and 12b. At the bottom of the casing 20 is a group 1 of at least two electrode units .
4a and 14b are arranged. Toner container 21
Can be arranged separately and attached to the casing 20.

When the printer unit 10 operates,
The toner particles 11 flow through the opening 24 toward the above-described support member 26. The support members 26 have shanks that are angled with respect to each other. This shank directs the flow of toner particles 11 to guide bar 28. Stirring blade 25
Are rotatably arranged to prevent the particles from aggregating with each other and forming clumps that obstruct flow. Guide bar 28
Guides the particle stream towards two leveling rollers 29a and 29b. The leveling rollers 29a and 29b
It may be made of some kind of suitable material, such as foam rubber, or a brush or the like may be arranged. Toner particles 1 sent to toner carrier members 12a and 12b
1 is leveled by a doctor blade 27 into a uniform layer.

The electrodes described below are connected to a known type of drive circuit (not shown) and can be controlled simultaneously or individually. By grounding (0V) the toner carrier members 12a and 12b, connecting the counter electrode 15 to a 1.5 kV voltage source or the like, and controlling the electrodes at 300V, the passage through the opening 17 is at least partially opened and closed,
An attraction field passes through the passage, and attracts the toner particles 11 from the toner conveying portions 12a and 12b toward the counter electrode 15. Counter electrode 15 is for both electrode units 14a and 14b, a group of electrode unit 1
4a or 14b,
Alternatively, one counter electrode 15 is arranged for each opening 17.

An information carrier, such as a paper sheet, is inserted between the toner carrier members 12a, 12b and the (single / plural) counter electrode 15, and by applying an appropriate control voltage, the passage is opened by the opening 17. Open, toner particles 1
1 is conveyed onto a paper sheet and is fixed when the paper sheet passes through a heating means (fixing mechanism [not shown]). The problem described above is that the electrode unit 14 is divided into two or more groups 14.
a and 14b. Depending on the applied area, the length of the toner particle transport band 35 (FIG. 3) is reduced (W ′> W / 2 (FIGS. 3 and 6)). The radius of the carrier member 12 can be reduced, and Δl
_k is significantly reduced and print quality is improved. Toner particles
The length of the transport band 35 can be shortened by moving the electrode 14 interposed on one side to the other narrow bands 35a and 35b and bringing the electrodes 14 closer to each other. The toner from each toner carrier member 12 is shown in FIGS.
According to the embodiment shown up to this point, instead of the four openings 17 according to the embodiment shown in FIGS. 1 and 3, instead of the four openings 17 being distributed through the two openings 17 continuous with the opening 24, the information carrier can be more evenly distributed. To the toner. Further, the conductor area is reduced, and the toner carrier member 1
2 eliminates the need for the conductor to rotate in the same direction as it extends into the ring electrode, resulting in a "curtain effect".
effect) is removed.

FIG. 5 is a partially enlarged view showing another embodiment according to the present invention. Toner carrier members 12a and 12
b is interlocked with the grounded spacer means. Further, the spacer means 32 functions as a doctor blade and also as a shielding means against an electric field which extends from the plurality of electrodes and obstructs the electric field image of another electrode unit 14. The electric field image means the appearance of the electric field.

FIG. 6 shows a part of the electrode units 14a and 14b from above, in which case the reference numerals A "1-A"
4 corresponds to the reference signs A1-A4 in FIG. Most with the adjacent electrode A "1, A" 3, A "2, A" 4 is the group 14a and 14b of each electrode units, respectively electrodes
It is preferable that the unit 14 and the information carrier 13 are arranged at an equal distance in the relative direction .

[0022] In the embodiment shown in FIG. 7, the toner carrier member 12a and 12 b are connected to a control voltage source Vp and Vnp through the switching means 30. The switch means 30 can be composed of a multiplexing circuit, a circuit breaker, and the like. Groups 14a and 1 4b of the electrodes 16 of the electrode Yunitsuto is narrowing 35a, the number of 35b, by coupling the two drive circuits 31, divided into at least two groups. The drive circuit 31 preferably supplies a high control voltage to the electrodes 16, preferably of the conventional type, according to a signal from a main controller not shown.
In operation, the voltage sources Vp and Vnp indicate a printing voltage source and a non-printing voltage source, ie, when the switch means 30 connects one of the toner carrier members 12a or 12b to Vp, the toner carrier member 12a, etc. The transfer of the toner particles 11 from the toner carrier member 12 becomes possible,
At this time, the electrodes A1 or A3 are applied with an appropriate voltage. At the same time, when the toner carrier member 12 is connected to Vnp, the toner particles 11 are separated from the toner carrier member 12 even when the electrodes A2 and A4 are connected to a printing voltage source leading to the drive circuits 31a and 31b. Not transported. Naturally, the opposing electrode 15 can be divided and switched as described above.

Also shown in this embodiment is another type of doctor blade 27a and 27b which scrapes toner particles 11 from toner member 12 and smoothes toner particles 11 on toner carrier member 12. Leveling.

[0024]

FIG. 8 is a view showing a preferred embodiment of the electrode unit 14. As shown in FIG. This electrode unit 14 has a resolution of 600 dpi (do
ts per inch), and the above-mentioned electrode unit 14 was designed for 300 dpi printing, but the solution used in this embodiment applies equally to any electrode unit 14 according to the present invention. You can also. Referring to FIG. 8, the electrode unit 14 includes a section 36 of conductors 33 that are coupled. This compartment 36 is generally connected to the same voltage source as the voltage applied to the electrode 16 and prevents the toner particles 11 from moving from the toner carrier member 12 onto the information carrier. The plurality of conductors 34 extend from the compartment 36 between the electrodes 16 and shield two adjacent annular electrodes 16 to reduce interference between adjacent annular electrodes 16 that may occur during printing.

Further, the narrow bands 35a and 35b can be adjusted. Referring to FIG. 8, since the distance between the toner carrier member 12 and the rows r1 and r4 of the electrodes 16 is longer than the rows r2 and r3, the voltage applied to the former rows r1 and r4 is increased, that is, V _r1 , _r4 > V _r2 ,
can be _r3 . Where V _rx is the electrode 1 in column x
6 shows the applied voltage.

Changing the size of the electrode 16;
That is, if S _rx is the size of the electrode 16 in column x, then S _rx
By setting _r1 , _r4 > _Sr2 , _r3 , the electrode 16 can be further reduced in size to increase the density of the electrostatic field, that is, the distance to the toner carrier member 12 can be further increased.

Further, by dividing or pulsing the total printing time t _tot , the actual printing time tp can be changed, which is shown in the graph of FIG. In this case, the time for columns r1 and r4 is equal to columns r2 and r3
And longer than time against. Also, the voltages for columns r1 and r4 are higher than the voltages for columns r2 and r3. Referring back to FIG. 8, the same voltage application can be applied to the upper row of the drawing at the same timing, so that the upper opening 17 overlaps the lower opening.

Further, the present invention can be used for a printer including another electrode unit other than the above-mentioned type.
This electrode is of the type having a woven electrode net as described in U.S. Pat. No. 5,036,341. This electrode may be of the type described in GB 2,108,432 and surrounds permeable openings located on both sides of the insulator and regulates toner particles through the openings described above. Although the above embodiments generally show a printer unit having a divided toner particle transport zone,
Those skilled in the art will appreciate that multiple solutions are available for printer units having a single toner particle transport zone or for printing devices that use multiple printer units.

Of course, the present invention is not limited to the illustrated embodiment described above, and many modifications and variations are possible within the scope of the claims.

[0030]

According to the present invention, the print quality can be improved by eliminating the white line noise and the curtain effect.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an entire conventional printer device drawn on a supernatural scale.

FIG. 2 is a schematic diagram illustrating a relationship between a distance between a toner carrier member and an opening of an electrode unit.

FIG. 3 is a partially enlarged schematic plan view of an electrode unit.

FIG. 4 is a schematic cross-sectional view showing the entirety of a preferred printer unit according to the present invention.

FIG. 5 is a schematic cross-sectional view of an enlarged portion of a toner particle transport band according to a second embodiment of the present invention.

FIG. 6 is a schematic front view showing an electrode unit according to the present invention.

FIG. 7 is a schematic view showing another embodiment of the present invention in which toner conveyance is controlled using a toner carrier member.

FIG. 8 is a view showing a preferred embodiment of the electrode unit according to the present invention.

FIG. 9 is a diagram showing timing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Printer unit 11 Toner particle 12 Toner carrier member 12a, b Toner carrier member 13 Information carrier 14 Electrode unit 14a, b Electrode unit 15 Counter electrode 16 Electrode 17 Opening 19 Conductor 20 Casing 21 Toner storage part 22 Toner transport part 23 Separation bar 24 Opening part 25 Stirrer blade 26 Support member 27 Doctor blade 28 Guide bar 29a, b Equalizing roller 30 Switch means 31 Drive circuit 32 Spacer means 33 Conductor 34 Conductor 35 Toner particle transport band 35a, 35b Narrow band 36 Conductor section

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 2/385 B41J 2/40

Claims (17)

(57) [Claims] 1. A printer unit for a printing apparatus, comprising at least one printer unit (10), said printer unit (10) including one toner container (21) for toner particles and an electrode unit (14). (1
0), wherein the electrode unit (14) includes an electrode (1 ).
6), as well as organic and an opening (17) to be wrapped <br/> enclosed at least in part by said electrode (16), the toner
Communicating with the storage section (21) or this toner storage section (21)
Carrier member disposed in a closed space (22)
(12) The counter electrode and the toner carrier member
Information carrier insertable between (12) and counter electrode (15)
A) The attraction electric field toward (13) causes the toner particles
And the toner carrier member (12), the electrode unit (14) and / or the counter electrode (15) are connected to the electrode unit (14) and the information carrier (1).
3) The two electrodes (A1, A4;
A "1, A" 4) are arranged to form a toner particle transport zone (35) to generate the attractive electric field, and the attractive electric field directs the toner particles through the opening (17) to the counter electrode ( Printer unit (1) drawn to 15)
0), the toner particle transport zone (35) has at least two narrow
The narrow band includes a toner carrier member (12a, 12b).
And the toner carrier members (12a, 12b)
The toner storage unit (21) or the toner storage unit (2)
1) is provided in the space (22) communicating with
A plurality of strips corresponding to the number of strips, and the narrow strips have openings (17) and electrodes (1).
6) electrode group (14a,
Printer unit, characterized in that it comprises a 14b) and (10). 2. The toner carrier member (12a, 1),
2b), the electrode (16) is connected to the drive circuit (31a,
2. An arrangement according to claim 1, wherein the first and second openings are arranged so as to rotate in a direction opposite to a direction extending from the first opening to the opening.
The printer unit as described. 3. The group of electrode units (14a,
14b) The most adjacent electrode (A "1, A") in each
3; A "2, A" 4) electrode and information carrier (13)
3. The printer unit according to claim 1, wherein the distances in the relative directions are the same. 4. The toner carrier member (12a, 12a)
4) The printer unit according to claim 1, wherein each of the printer units includes a toner leveling roller (29a, 29b). Wherein said toner accommodating portion (21) or with this
5. The printer unit according to claim 1, wherein the communicating space includes at least one rotary mixing blade. 6. 6. guide has a bar (28), a printer unit according to claim 5, wherein the inducing a flow of toner to the smoothing roller (29a, 29 b). 7. The printer unit according to claim 1, wherein a spacing means (32) is arranged with respect to the toner carrier members (12a, 12b). 8. The toner carrier member (12a, 1)
8. The printer unit according to claim 1, wherein 2b) is connected to a control voltage source via switch means (30) and is arranged to be controlled individually or simultaneously. 9. 9. The printer unit according to claim 1, wherein each of the narrow bands is arranged together with a corresponding counter electrode. 10. The device according to claim 9, wherein each of the opposing electrodes is connected to a voltage source via the switch means, and is arranged to be controlled individually or simultaneously.
The printer unit as described. 11. The driving device according to claim 11, wherein said electrode is a driving means.
10. The printer according to claim 8, wherein the printers are classified by being arranged in the lines connected to a, 31b), and each line is controllable by being connected to the same or different voltage source. unit. 12. The electrode unit group (14).
a, 14b) apply a voltage to the electrode (16), and the toner particles are transferred to the toner carrier member (12a, 12b).
b) in the direction of the counter electrode (15) from
2. The printer unit according to claim 1, comprising a section (36) consisting of a conductor connected to a voltage source for shielding between the electrodes (16). 13. The printer unit according to claim 12, wherein the conductor extends from the section to between the electrodes. 14. The method of claim 13, wherein the distance to the toner carrier member (12) (l _k) is long the opening (17), the distance is short opening up the toner carrier member (12) (17)
The printer unit according to claim 1, wherein the printer unit is smaller than the printer unit. 15. The distance to the toner carrier member (12) (l _k) is long the electrode (16) is connected to the toner carrier member (12) distance is a voltage higher than near the electrode (16) to The printer unit according to claim 1, wherein: 16. The distance to the toner carrier member (12) (l _k) is long the electrode (16), the distance to the toner carrier member (12) is applied longer than near the electrode (16) The printer unit according to claim 1, wherein: 17. At least one printer unit (10) is arranged, said printer unit (10)
Includes one toner container (29) and an electrode, so that the toner particles (11) can be separated from the toner carrier member (12) by the toner carrier member (12) in the toner particle transport zone by at least one opposition. A method for improving print quality in a printing device conveyed by one or more attractive electric fields towards an information carrier (13) insertable between said electrodes (15), wherein said printer unit comprises at least two toner carriers. members (12a, 12b) arranged, openings in the electrode unit (14) to (17) and electrode (16) electrode
(16) and less in the relative direction of the information carrier (13) <br/> also more to place in two groups (14a, 14b), the toner which has been divided into at least two narrow bands
A method comprising forming a particle transport zone (35) .