JPH10151789A - Method for controlling powder fly type printing and printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To print with high quality by improving a shift of printing dots in a powder fly-type method of printing. SOLUTION: Toners 62 are let to fly from a surface of a developing roller 61 by controlling an electric field of printing control electrodes 68, whereby printing dots 60 are formed on a paper 64 via through holes 67 in an insulating substrate 66. A conductive roller 65 is placed below the paper 64 to apply a voltage for accelerating the flying toners 62. The printing control electrodes 68 are formed via equal distances d1, d2, d3 in a moving direction of the paper 64 in the insulating substrate 66 of a flexible printed wiring board 69. Distances L1, L2, L3 of the printing dots 60 formed on the paper 64 are not always equal because of a bias of the electric field accelerating the flying toners 62 or a bend of the flexible printed wiring board 69, etc. For solving this, a voltage for controlling of the electric field which is adjusted in timing with the use of a delay circuit 81 is applied to a driving circuit included in an IC chip 74b at the downstream side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a powder flying print control method and a printing apparatus for printing by depositing a powdery developer on a print medium without forming an electrostatic latent image.

[0002]

2. Description of the Related Art Conventionally, a copier, a facsimile, a printer, and the like have been subjected to printing and recording using an electrophotographic system invented in 1938 by PF Carlson. In the electrophotographic method, an electrostatic latent image is formed on a photoconductive photoreceptor, toner, which is a charged powdery developer, is adsorbed, and the toner image is transferred to a printing medium such as paper to perform printing. Do. A powder flying method in which printing with toner is performed directly on a printing medium without forming an electrostatic latent image on a conductive photoreceptor has been proposed in, for example, Japanese Patent Application Laid-Open No. 8-5831.

FIG. 8 shows a schematic configuration of a powder flying type recording apparatus proposed in Japanese Patent Laid-Open No. 8-5831. The developing roller 11, which is a developer carrier, has a cylindrical entire outer peripheral surface of N.
Or a magnet roller magnetized in S,
The toner 12, which is a powdery developer having magnetism, is held while being magnetically attracted. The amount of holding is regulated by a doctor blade 13 so that excessive toner 12 does not adhere. In order to transfer the toner 12 to the surface of the paper 14 as a print medium, the paper 14 is
And the conductive roller 15. Developing roller 11
A plurality of through holes 17 are formed in a flexible insulating substrate 16 made of a heat-resistant insulating film such as polyimide, and a print control electrode 18 is provided in the periphery of each through hole 17. The flexible printed wiring board 19 has a strip shape extending in the axial direction of the cylindrical developing roller 11, and the glass epoxy board 2 is provided on both ends in the width direction perpendicular to the axial direction.
0 and 21 are respectively arranged. Elastic foam layers 22 and 23 such as urethane sheets are interposed between the flexible printed wiring board 19 and the developing roller 11 except for the portion where the through holes 17 are formed. The distance between the print control electrode 18 and the print control electrode 18 is maintained. The paper 14 is transported from the right side to the left side in FIG. The guide 24 is provided for smoothly transporting the paper 14.

[0004] The developing roller 11 is magnetized as described above, and is supplied with a voltage of 0 to +300 V from a bias power supply 25.
Bias voltage is applied. Print control electrode 1
8, a voltage of about +300 V is applied from the control power supply 26. The conductor roller 15 has an acceleration power supply 27
An acceleration voltage of 00V is applied. The conductor roller 15 is
It is provided in an opening provided in a base 28 supporting the paper 14. Toner 12 held on the surface of developing roller 11
Selectively fly by electric field control by the print control electrode 18, accelerated by the conductive roller 15,
To the surface of the paper 14.

FIG. 9 shows a configuration related to the print control electrode 18 shown in FIG. Flexible printed circuit board 19 on which print control electrode 18 is formed and glass epoxy boards 20 and 2
1, a wiring pattern 32 formed on the insulating substrate 16 via the anisotropic conductive films 30 and 31 and a wiring pattern 33 formed on the glass epoxy substrates 20 and 21 are electrically connected. Is done. Flexible printed circuit board 1 as a whole
However, since the flexible printed wiring board 19 is expensive, only a portion where the print control electrode 18 is formed is used, and a glass epoxy substrate 20 is provided on both sides thereof.
21 is used. On the glass epoxy substrates 20 and 21,
A semiconductor integrated circuit (hereinafter abbreviated as “IC”) chip 34 including a drive circuit for driving the print control electrode 18 and a circuit component 35 such as a capacitor are mounted.
The glass epoxy substrates 20 and 21 are also provided with a connector 36 for making an electrical connection to the outside. Note that each I
Although the drive circuit in the C chip 38 drives a larger number of print control electrodes, it is shown in a small number for convenience of explanation.

FIG. 10 is an enlarged view showing the vicinity of the print control electrode 18. The print control electrode 18 is formed so as to surround the periphery of the through hole 17 provided in the insulating substrate 16.
The toner 12 flying through the developing roller 11
4 on. Therefore, if the distance between the print control electrodes 18 is as short as possible, high-resolution printing can be performed. However, since a relatively high voltage of about 300 V is applied to the control electrode 18 during printing as described above, the interval cannot be made too small. For this reason, the print control electrode 18 is
The print control electrodes 18 arranged in a plurality of rows and adjacent to each other
It is preferable to take a staggered arrangement as a whole so that are located on different rows. Such a print control electrode 18
According to this arrangement, printing on one linear print dot perpendicular to the transport direction of the paper 14 is performed four times.

FIG. 11 shows a schematic electrical configuration for performing printing using the print control electrode 18 as shown in FIG. From the signal generation circuit 40, the individual print control electrodes 1
8 is serially derived, a clock signal indicating the timing of deriving each print data, a latch signal indicating that the derivation of one print data has been completed, and a time for performing the electric field control by the print control electrode 18 are determined. Gate output signals for performing the operations are derived. Each signal is supplied to an upstream drive circuit 41, 42, 4 implemented by the IC chip 34.
3, 44 and the downstream drive circuits 45, 46, 47, 4
8 respectively. In each of the drive circuits 41 to 48, a shift register 49 for sequentially shifting print data in accordance with a clock signal and converting serial data into parallel data for each print control electrode 18 is provided. An output gate 50 for driving the print control electrode 18 according to the output is included. Drive circuit 41 on the upstream side
An inverter 51 is provided to invert the polarity of the print data to be provided to the drive circuits 45 to 48 on the downstream side. Although the drive circuits 41 to 48 can normally drive a larger number of print control electrodes 18, for the sake of convenience of description, a case is shown in which four print control electrodes 18 are driven.

FIG. 12 shows the operation timing of each section in FIG. The clock signal is generated at a constant cycle, and the print data to be supplied to the drive circuits 41 to 48 is derived for each time T0. When the derivation of the print data is completed, a latch signal is derived, and the output of the shift register 49 is latched by the output gate 50. Subsequently, an output gate signal is derived for the time T2, and the output gate 50 outputs the latched print data. The period T1 of the latch signal is
4 is a predetermined time calculated from the moving speed and the printing resolution. The relationship between these periods differs depending on the clock speed, but usually T0 <T2 <T1.

[0009]

The distances d1, d2 and d3 between the rows of the print control electrodes 18 as shown in FIG.
It is manufactured to be at equal intervals by laser processing or the like. However, as shown in FIG. 8, the flexible printed wiring board 19 is bent along the cylindrical surface of the developing roller 11, and the middle distance d2 in FIG. On the other hand, d1 and d3 are intervals in an inclined state. For this reason, the flying direction of the toner 12 passing through the through hole 17 and adhering to the surface of the paper 14 changes in the transport direction of the paper 14, and the interval between the printing dots is such that the flexible printed wiring board 19 is developed in a plane. Spacing d1, d2, d3
They are different even if they are equal. Further, the flying direction of the toner 12 is also affected by the electric field for electric field control and the electric field for acceleration formed by the print control electrode 18 and the conductive roller 14 being changed between the upstream side and the downstream side.

FIG. 13 shows a print control electrode 1 as shown in FIG.
8 shows an example of a state in which the printing positions of the upstream side and the downstream side are shifted in the arrangement of No. 8. As shown in (1), printing at the same time
When the print dots 55, 56, 57, and 58 for columns are formed, the actual print positions indicated by oblique lines with respect to the normal print positions indicated by the broken lines are the print dots 57, 58 on the downstream side.
In this case, as shown in (2), the print dots 55 to 58 on the line perpendicular to the transport direction that is finally formed by transporting the paper 14 also shift zigzag.

The displacement shown in FIG.
This occurs even when the through hole 17 formed on the upper side is displaced within the range of working accuracy, or when distortion is generated on the upstream side and the downstream side due to heat applied in the bonding step of the flexible printed wiring board 19 and the like. sell.

An object of the present invention is to provide a powder flying type printing control method and a printing apparatus which can improve the deviation between the printing control electrode 18 and the position where the printing control electrode 18 adheres to the printing medium and can obtain a high quality printing image. It is to be.

[0013]

According to the present invention, there is provided a printing medium which relatively moves from a cylindrical developer carrier holding a powdery developer in a direction intersecting the axis of the developer carrier. A powder flying type print control for printing by attaching a developer which is made to fly by electric field control by a plurality of print control electrodes formed at intervals in the axial direction and shifted in the direction of the movement. In the method, while the relative movement is continuously performed, the application of the electric field control voltage for causing the developer to fly to each print control electrode is periodically performed, and the print control electrodes having different positions with respect to the movement direction are performed. In contrast, the present invention provides a powder flying type printing control method characterized in that control is performed such that an electric field control voltage is applied at different timings.

According to the present invention, the position of the developer flying from the cylindrical developer carrier and adhering to the print medium is adjusted by the timing of the electric field control voltage applied to the print control electrode. Since the voltage is applied at different timings according to the movement position of the print medium, the shift of the print position on the print medium in the movement direction is reduced, and printing can be performed with high quality.

Further, in the present invention, the print control electrodes are arranged in a zigzag pattern on a plurality of rows parallel to the axial direction and having a constant interval, wherein the axial direction and the direction of the movement are perpendicular to each other. With respect to the movement, the timing of the electric field control voltage applied to the print control electrode on the upstream side and the print control electrode on the downstream side is shifted.

According to the present invention, since the print control electrodes are arranged in a staggered manner on a plurality of rows parallel to the axial direction and at a constant interval, printing on the same line parallel to the axial direction is performed a plurality of times. Separation can be performed with high precision. Since the adjacent control electrodes are arranged in a staggered manner, the distance between them can be increased, and the insulating state can be maintained even when a high voltage is applied for printing control.

Further, the present invention relates to a printing medium which moves relatively from a cylindrical developer carrier holding a powdery developer in a direction intersecting the axis of the developer carrier. In a powder flying print control device for printing by attaching a developer to be sprayed by electric field control by a plurality of print control electrodes formed at intervals in the direction and shifted in the direction of the movement, The electrode is formed on a flexible insulating substrate that is disposed at a predetermined distance from the developer carrier, and a moving unit that moves the printing medium relative to the developer carrier and the insulating substrate. Signal generation means for periodically deriving a print signal for performing electric field control at each print control electrode based on data to be printed,
A drive unit for driving each print control electrode according to a print signal derived from the signal generation unit, and a print signal derived from the signal generation unit is provided to the drive unit at a timing shifted while corresponding to the position of the print control electrode. A powder flying type printing apparatus comprising an adjusting means.

According to the present invention, while the printing medium is continuously moved by the moving means, the application of the voltage for controlling the electric field to the plurality of control electrodes is applied to the driving means by shifting the timing in accordance with the position in the moving direction. Since the adjusting means is provided, it is possible to perform high-quality printing with little deviation in the moving direction of the printing medium.

Further, in the present invention, the adjusting means may be arranged such that, with respect to the movement of the printing medium by the moving means, one of the driving means for driving the print control electrodes on the upstream side and the downstream side, respectively, has a printing signal higher than the other. Is delayed. According to the present invention, the adjusting unit provides one of the driving units for driving the print control electrodes on the upstream side and the downstream side with respect to the movement of the print medium by the moving unit, and provides the print signal with a delay from the other. With a simple configuration, it is possible to adjust the displacement of the printing position and perform high-quality printing.

[0020]

FIG. 1 shows a schematic configuration of a powder flying printing apparatus according to an embodiment of the present invention. In the present embodiment, an image is represented by a set of print dots 60.
The developing roller 61 which is a cylindrical magnet roller magnetically attracts a toner 62 which is a magnetic developer. The thickness of the layer of the toner 62 to be sucked is regulated by a doctor blade 63. Below the developing roller 61, paper 64 as a printing medium is supplied at intervals. A conductive roller 65 is provided below the paper 64. Developing roller 6
1, a plurality of through holes 67 are provided in a flexible insulating substrate 66 made of a heat resistant insulating film such as polyimide at a position close to the outer peripheral surface.
A flexible printed wiring board 69 on which 8 is formed is arranged. Glass epoxy substrates 70 and 71 are connected to both ends of the flexible printed wiring board 69. Developing roller 61
Elastic foam layers 72 and 73 such as a urethane foam sheet are interposed around the portion where the through hole 67 is formed between the flexible printed wiring board 69 and the flexible printed circuit board 69.

On the glass epoxy substrates 70 and 71, an IC including a drive circuit for driving the print control electrode 68 and the like are provided.
Chips 74a and 74b (hereinafter collectively referred to by reference numeral "74") are mounted. A gate output signal for driving the print control electrode 68 from the signal generation circuit 80 is supplied to a drive circuit formed in the IC chip 74. This signal corresponds to the upstream I
The drive circuit in the C chip 74a and the IC chip 7 on the downstream side
4b.
To adjust the timing, a delay circuit 81 is inserted between the signal generation circuit 80 and the drive circuit in the IC chip 74b on the downstream side.

According to the present embodiment, the output timing for electric field control given to the drive circuit provided in the IC chip 74b on the downstream side is delayed by the delay circuit 81.
The intervals d1, d2, d3 between the four rows of print control electrodes 68 are
The flexible printed circuit boards 69 can be formed at equal intervals in a state where an electric field is applied on a plane, and the intervals L1, L2, and L3 between the print dots 60 formed on the paper 64 can be adjusted to be equal.

FIG. 2 shows the flexible printed circuit board 6 of FIG.
9 shows the configuration of the third embodiment. Since the flexible printed wiring board 69 is more expensive than the glass epoxy boards 70 and 71,
The IC chip including the IC chip 74 and the delay circuit 81 is provided on the glass epoxy substrates 70 and 71. A part of the flexible printed wiring board 69 is extended to form signal input portions 82 and 83. Although the number of the print control electrodes 68, the number of the IC chips 74, or the number of the print control electrodes 68 connected to each IC chip 74 are shown in a small number for the sake of convenience of explanation, actually, the number is larger. Become.

FIG. 3 shows a schematic electrical configuration in the embodiment of FIG. The print control electrodes 68 on the upstream side are connected to the driving circuits 91, 92, 93, 9 in the plurality of IC chips 74a.
4 driven. The downstream print control electrode 68 is connected to the drive circuits 95, 96, 97,
Driven by 98. The gate signal derived from the signal generation circuit 80 is given to the downstream drive circuits 95 to 98 by adjusting the timing by the delay circuit 81. The print data is supplied as it is from the signal generation circuit 80 to the upstream drive circuits 91 to 94 and the downstream drive circuit 9
5 to 98 are provided via an inverter 90. Each of the drive circuits 91 to 98 includes a shift register 99 that converts serially derived data into parallel data, and an output gate 100 that provides an output of the shift register 99 to each print control electrode 68. The control circuit shown in FIG. 3 is mostly a relatively low voltage for normal semiconductor logic circuit operation,
For example, it operates at about 5V. The print control electrode 68 includes
As described above, since a relatively high voltage of about +300 V needs to be applied, the output gate 100 is manufactured by a process with a high withstand voltage, and also converts the signal voltage level.

FIG. 4 is a timing chart of the electrical configuration of FIG. The clock signal, print data, and latch signal are the same as those in FIG. 12, but the gate output control signal is given, for example, with the downstream side delayed by T3. That is, at times t11, t12, t
13, print data is derived in a fixed period T1 and a period T0 shorter than the period of the T1, latched by the output gate 100 with a latch signal, and printed control electrodes by the upstream drive circuits 91 to 94 according to the gate output signal. The electric field control of 68 is performed, and further, the period of T2 after the passage of T3,
Electric field control is performed by the drive circuits 95 to 98 on the downstream side. The relation between these periods is usually T0 <T2 <T1, and T0 + T2 + T3 <T1.

FIG. 5 is a two-dot chain line (1) with a delay on the downstream side when printing a row of print dots 60 perpendicular to the moving direction of the paper 64 in four times according to this embodiment. This shows a state in which printing is performed at a timing and printing can be performed with a small displacement in the moving direction as shown in (2).

FIG. 6 shows another embodiment of the present invention.
The concept of increasing the printing density in the direction perpendicular to the moving direction by tilting the axis direction of the developing roller and the moving direction of the paper at a constant angle θ instead of perpendicularly will be described. As shown in (1), if the arrangement point of the printing dots 60 is inclined with respect to the moving direction, the printing dots 6 on a line perpendicular to the moving direction are formed.
The distance between zeros can be further increased as shown in (2). In this case, since the position of the print dot 60 is also shifted with respect to the moving direction, the timing is adjusted to reduce the shift in the moving direction, and high-quality printing can be performed.

FIG. 7 shows a schematic configuration of still another embodiment of the present invention. In the present embodiment, FIGS.
In the second embodiment, a toner image is formed directly on a print medium such as paper, whereas a toner image is attached on an intermediate medium and then transferred onto a print medium to perform final printing. Also,
In the print head 101, a developing roller 102 and a hopper 103 for storing toner are provided, a motor 104 for driving the developing roller 102 is incorporated, and a reciprocating movement in a direction perpendicular to the paper surface along a guide shaft 105 is provided. . Below the developing roller 102, plate electrodes 106 are arranged at intervals. Print head 101 and plate electrode 10
6, the intermediate belt 107 is inserted. The intermediate belt 107 is formed endlessly from a heat-resistant polyimide film or the like, and is stretched between support rollers 108. An acceleration voltage is applied to the plate electrode 106 from an acceleration power supply 109.

The intermediate belt 107 inserted between the print head 101 and the plate electrode 106 is cleaned while the cleaning roller 111 of the cleaning unit 110 is rotated by a motor 112 on the upstream side. Below the intermediate belt 107, paper 113 as a printing medium is
4, the paper is taken out of the stocker 115 one by one and supplied. The image of the toner 117 supplied from the print head 101 is transferred as print dots 118 to the paper 113 at the fixing device 116. The paper 113 to which the print dots 118 have been transferred is accumulated on the tray 119 and waits for being taken out. The print head 101 includes a developing roller 1
A print control electrode 120 is provided below 02, and controls the flying state of the toner 117 by electric field control, and controls whether or not the toner 117 adheres as print dots 118 on the intermediate belt 107.

According to this embodiment, even if the developing roller 102 and the printing control electrode 120 are downsized, printing can be performed on the paper 113 which is a relatively large printing medium. Further, a print control electrode 120 and a plate-like electrode 106 serving as an acceleration electrode are provided.
Between the intermediate belt 107 having a constant thickness.
Can be printed under stable conditions. The printing medium can easily print not only on ordinary recording paper but also on a thick target such as an envelope or a transparent sheet for an overhead projector. It should be noted that although the magnetic toner is used as the toner 62, the printing timing control can be similarly performed for the non-magnetic toner.

[0031]

As described above, according to the present invention, with respect to the relative movement of the print medium with respect to the developer carrier and the print control electrodes, the displacement of the print dots due to the difference in the position of the print control electrodes in the moving direction is reduced. Since the timing for performing the electric field control is adjusted and reduced, high-quality printing can be performed.

According to the present invention, a plurality of lines are simultaneously printed in a direction perpendicular to the moving direction, and the paper is moved so that the final printing is performed in the moving direction of the printing points arranged on a line perpendicular to the moving direction. The displacement can be reduced, and high-resolution printing can be performed with high quality.

Further, according to the present invention, while the printing medium is relatively moved with respect to the developer carrier and the printing control electrode by the moving means, a signal is generated according to a difference in the position of the printing control electrode in the moving direction. The print signal for controlling the electric field derived from the means is driven by adjusting the timing so that it corresponds to the position of the print control electrode by the adjusting means, so that the dot position to be printed is optimized and high quality printing is performed. It can be performed.

According to the present invention, with respect to the movement of the printing medium by the moving means, a printing signal given to one of the driving means for driving the printing control electrodes on the upstream side and the downstream side, respectively,
High-quality printing can be easily performed simply by delaying the printing signal given to the other side.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a plan view of the flexible printed wiring board 69 of FIG.

FIG. 3 is a block diagram showing a schematic electrical configuration for control of the embodiment of FIG. 1;

FIG. 4 is a time chart of the electrical configuration of FIG. 3;

FIG. 5 is a diagram showing the effect of improving print dots according to the embodiment of FIG. 1;

FIG. 6 is a diagram showing an arrangement of print control electrodes and an arrangement state of print dots according to another embodiment of the present invention.

FIG. 7 is a sectional view showing a schematic configuration of still another embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a schematic configuration of a powder flying recording apparatus which is the basis of the present invention.

FIG. 9 is a partial plan view of the flexible printed wiring board 19 of FIG.

FIG. 10 is a partial plan view showing an arrangement state of a print control electrode 18 of FIG. 9;

11 is a block diagram showing a schematic electrical configuration for performing the control of FIG. 8;

FIG. 12 is a time chart illustrating an operation state of each unit in FIG. 11;

FIG. 13 is a diagram showing a state of displacement of print dots by the powder flying recording apparatus of FIG. 8;

[Explanation of symbols]

 60, 118 Printing dot 61, 102 Developing roller 62, 117 Toner 64, 113 Paper 65 Conductor roller 66 Insulating substrate 67 Through hole 68, 120 Printing control electrode 69 Flexible printed wiring board 74, 74a, 74b IC chip 80 Signal Generation circuit 81 Delay circuit 91 to 98 Drive circuit 99 Shift register 100 Output gate 101 Print head 116 Fixing device

Claims (4)

[Claims] 1. A printing medium moving relatively in a direction intersecting the axis of a developer carrier from a cylindrical developer carrier holding a powdery developer, the printing medium being spaced in the axial direction. A powder flying type print control method for printing by attaching a developer to be fly by electric field control by a plurality of print control electrodes formed with a gap and shifted in the direction of the movement; Is continuously performed, and an electric field control voltage for causing the developer to fly to each print control electrode is periodically applied, and to the print control electrodes having different positions in the moving direction,
A powder flying type print control method, characterized in that control is performed such that electric field control voltages are applied at different timings. 2. The printing apparatus according to claim 1, wherein the axial direction is perpendicular to the moving direction, and the print control electrodes are arranged in a staggered manner on a plurality of rows parallel to the axial direction and at a constant interval. 2. The method according to claim 1, wherein the timing of the electric field control voltage applied to the upstream print control electrode and the downstream print control electrode is shifted. 3. A printing medium moving relatively in a direction intersecting with the axial direction of the developer carrier from a cylindrical developer carrier holding a powdery developer, is spaced from the cylindrical developer carrier in the axial direction. In a powder flying type print control device for printing by attaching a developer to be fly by electric field control by a plurality of print control electrodes formed with a gap and shifted in the direction of the movement, the print control electrode comprises: Moving means for moving a print medium relative to the developer carrier and the insulating substrate, the moving means being formed on a flexible insulating substrate arranged at a predetermined distance from the developer carrier; Signal generation means for periodically deriving a print signal for performing electric field control in each print control electrode based on power data, and drive means for driving each print control electrode in accordance with a print signal derived from the signal generation means When The print signal derived from the signal generating means, to correspond to the position of the print control electrode, powder particle jumping printing apparatus characterized by comprising adjustment means for applying to the driving means at different timings. 4. The printing apparatus according to claim 1, wherein the adjusting unit delays a printing signal for one of the driving units that respectively drive the upstream and downstream printing control electrodes with respect to the movement of the printing medium by the moving unit. 4. The method according to claim 3, wherein
A powder flying type printing apparatus as described in the above.