JPH09216407A - Recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a homogeneous electrostatic charge image by making ionic beams go straight. SOLUTION: Line electrodes 2-1-2-4 are formed on the downside of an insulator substrate 1, and row electrodes 3-1-3-n are formed on the upside of the insulator substrate 1. The electric fields between the line and row electrodes becomes concurrent to ionic beams only when the line electrodes to which an 'L' level voltage is applied overlaps the row electrodes to which a 'H' level voltage is applied. Ionic beams pass through ionic beam pass holes 4 located at overlapping position. Dummy electrodes 5-1 and 5-2 are given the same electric potential as that of the row electrodes at the time the ionic beams are hindered from passing through. The outside and inside electric fields across the electrodes 2-1-2-4 are kept symmetric, causing the ionic beams passing through the passing holes 4 to go straight in the direction perpendicular to the line electrodes without a deflection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording head used in an electrostatic recording type facsimile or printer.

[0002]

2. Description of the Related Art An electrostatic recording method (ion flow recording method) by controlling an ion flow is promising as a recording method capable of providing a high quality color image at a low running cost.
FIG. 4 is a view showing the principle of controlling the ion flow, 11 is an ion generation source, 12 is an ion flow control plate consisting of two electrodes having an opening 14, and 16 is a conductive material 18 and a dielectric material. A recording medium on which the resin 19 is formed, and 17 are ions emitted from the ion generation source 11 by corona discharge.

The ions 17 are controlled by changing the electric field between the two electrodes of the ion flow control plate 12.
That is, when the inter-electrode electric field is in the forward direction with respect to the ion flow as shown in FIG. 4A, the ion flow passes through the opening 14 and the inter-electrode electric field is reverse as shown in FIG. 4B. In the case of direction, passage is blocked. In this way, the recording medium 16 is selectively irradiated with the ions 17 to form a charge image on the recording medium 16. Normally, toner is attached to the recording image to record as a visible image.

FIG. 5 is a plan view of a conventional recording head utilizing such a basic principle, and FIG. 6 is a sectional view taken along the line I--I of FIG. 1 is an insulator substrate, 2-1 to 2-4 are insulator substrates 1
Row electrodes formed on the lower surface of the insulating substrate 1, 3-1 to 3-n are column electrodes formed on the upper surface of the insulator substrate 1, and 4 is the opening 14 described above.
Is an ion flow passage hole, and 6 is a recording medium. By thus forming the matrix configuration of the row electrodes 2-1 to 2-4 and the column electrodes 3-1 to 3-n, the number of the ion flow passage holes 4 is increased and the resolution of one line (dots of one line). The number is increased to 4 (the number of row electrodes) × n (the number of column electrodes)), and the circuit required for control is simplified. Then, by applying an ion flow passage hole selection pulse voltage to the row electrodes 2-1 to 2-4 and the column electrodes 3-1 to 3-n, the ion flow is selectively irradiated from a specific ion flow passage hole 4. , Electrostatic recording.

At this time, the central row electrodes 2-2, 2-3
While the ion flow 17 passing through the ion flow passage hole 4 at the position of (4) goes straight toward the recording medium 6, the row electrode 2-
The ion flow 17 passing through the passage holes 4 at the positions 1 and 2-4 is deflected in the direction perpendicular to the row electrodes as shown in FIG. 6 and does not proceed perpendicularly to the ion flow control plate. This is because, in such a recording head, only when the row electrode to which the “L” level voltage is applied and the column electrode to which the “H” level voltage is applied overlap each other with the insulator substrate 1 in between. The electric field between the column electrode and the row electrode is in the forward direction with respect to the ion flow 17, and the ion flow 17 passes through the ion flow passage hole 4 at the overlapping position.

By applying a voltage of "L" level to a certain row electrode, when the ion stream 17 passes through the passage hole 4 of this row electrode, the remaining row electrodes block the passage of the ion stream "H". The electric potential is set to a level "" so that the ion flow 17 cannot pass through the passage holes 4 of these row electrodes. Thereby, for example, the row electrode 2-2
When the ion flow 17 passes through the passage hole 4 at the position, the potential of the row electrode 2-2 is, as can be seen from the description of FIGS. 4A and 4B, the row electrode 2-1 sandwiching this electrode. Since the potential is lower than that of the electrodes 2-3, the electrodes 2-1 to 2-2 and the electrode 2-3 are
An electric field from the electrode 2-2 to the electrode 2-2 is formed around the electrode 2-2. Therefore, the electric field around the row electrode 2-2 becomes uniform, and the ion flow 17 goes straight. This is row electrode 2
The same applies to the case of -3.

On the other hand, since only the row electrode 2-2 is adjacent to the row electrode 2-1 at the end, when the ion flow 17 passes through the passage hole 4 at the position of the electrode 2-1, the electrode 2- There is only an electric field around 1 around the electrode 2-2 to 2-1. Therefore, the electric field around the row electrode 2-1 cannot be in the same condition as the central part, which causes the ion current 17 to be deflected. This also applies to the row electrodes 2-4 at the ends.

[0008]

As described above, in the conventional recording head, the ion flow passing through the ion flow passage holes is deflected to reach a position deviating from the desired position on the recording medium, and Since a non-uniform electrostatic charge image is formed on the top,
There is a problem that recording unevenness easily occurs in the image.
The present invention has been made to solve the above problems,
An object is to provide a recording head capable of forming a uniform electrostatic charge image.

[0009]

According to the present invention, there is provided a recording head comprising:
The ion flow control plate includes an ion generation source and an ion flow control plate, and the ion flow control plate defines a recording position formed on the first surface of the insulating substrate so as to face the recording medium. A plurality of row electrodes that receive a voltage for selection and a voltage according to the recorded information that is formed on the second surface of the insulating substrate so as to intersect the row electrodes with the insulating substrate interposed therebetween are input. A plurality of column electrodes, an ion flow passage hole for passing an ion flow formed through the row electrode, the column electrode and the insulator substrate, and two row electrodes located at both ends of the plurality of row electrodes. A dummy electrode formed in parallel to the row electrode is provided outside the row electrode, and the same potential as that of the row electrode when blocking passage of an ion current is applied to the dummy electrode. . By applying the same potential as the row electrodes when blocking the passage of the ion current to the dummy electrodes, the symmetry of the electric field around the row electrodes located at both ends is maintained, and the dummy electrodes pass through the ion current passage holes. The ion stream goes straight without being deflected in the direction perpendicular to the row electrodes.

Further, a dummy electrode formed in parallel with the two column electrodes located at both ends of the plurality of column electrodes is provided outside the column electrodes, and the dummy electrodes are applied to the column electrodes. The electric potential is applied within the voltage range. By applying to the dummy electrodes a potential within the voltage range applied to the column electrodes, the symmetry of the electric field around the column electrodes located at both ends is improved, and the ion flow through the ion flow passage holes is reduced. It goes straight without being deflected in the direction perpendicular to the column electrodes.

[0011]

1 is a plan view of a recording head according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line I--I of FIG. 1, and FIG. 3 shows each electrode of this recording head. It is a timing chart figure which shows the voltage waveform to apply. In FIGS. 1 and 2, 1 is an insulator substrate, 2-1 to 2-4 are row electrodes, 3-1.
˜3-n is a column electrode, 4 is an ion flow passage hole, 5-1 and 5-
Reference numeral 2 is a dummy electrode formed outside the row electrodes 2-1, 2-4, 6 is a recording medium in which a dielectric resin is formed on a conductive material, and 7 is an ion flow.

The ion flow control plate for controlling the ion flow 7 is
Insulator substrate 1, row electrodes 2-1 to 2-4, column electrodes 3-1 to
3-n, ion flow passage hole 4 and dummy electrodes 5-1, 5
-2. Then, the recording medium 6 is vertically moved by an unillustrated feeding mechanism with respect to the ion flow control plate fixed at a predetermined position, that is, the recording head, as shown by an arrow in FIG.

In order to carry out electrostatic recording using such a recording head, the row electrodes 2-1 to 2-4 are shown in FIGS.
The voltages A1 to A4 as shown in FIG.
1 and 3-2 correspond to the dot information of the image data shown in FIG.
The voltages B1 and B2 as shown in (g) and (h) are applied, respectively. It should be noted that although the description is given here that the voltage is applied only to the column electrodes 3-1, 3-2, the other column electrodes 3-
It goes without saying that a voltage corresponding to dot information is similarly applied to 3 to 3-n.

Only when the row electrode to which the "L" level voltage is applied and the column electrode to which the "H" level voltage is applied overlap with each other with the insulator substrate 1 sandwiched therebetween, between the column electrode and the row electrode. The electric field of is in the forward direction with respect to the ion flow 7, and the ion flow 7 passes through the ion flow passage hole 4 at the overlapping position.

Recording of one line is performed as follows by controlling the ion flow as described above. In the actual control, since the pitch of the row electrodes is larger than the resolution of the recording head, the cycle of the voltage pulses A1 to A4 is repeated several times while the medium 6 moves between the row electrodes. In order to simplify the explanation, the medium 6 is the row electrode 2-1.
It is assumed that the above cycle is performed once while moving from the position to the position of 2-4.

First, at time t1 in FIG. 3, the voltage A1 is set to the "L" level to select the row electrode 2-1 and the column electrode 3-.
A voltage pulse corresponding to dot information is applied to 1 to 3-n. As a result, the position of the row electrode 2-1 (the horizontal direction is 3-1
To 3-n), the ion flow 7 is selectively applied to the recording medium 6 from the ion flow passage hole 4 according to the dot information.
Then, at time t2, the voltage A2 is set to "L" level to select the row electrode 2-2, and the voltage pulse according to the dot information is applied to the column electrodes 3-1 to 3-n. As a result, the ion flow 7 is selectively applied to the recording medium 6 from the ion flow passage hole 4 at the position of the row electrode 2-2.

At this time, assuming that the recording medium 6 is moving from the upper side to the lower side in FIG. 1, the ion flow 7 is generated by the row electrode 2-1.
The irradiation is performed during the electric charge formed on the recording medium 6 by the selection. Then, at the time t3, the voltage A3
By selecting the row electrode 2-3 by the row electrode 2-3, the ion flow 7 passes through the passage hole 4 at the position of the row electrode 2-3, and the charge and the row formed on the medium 6 by the selection of the row electrode 2-1. It is irradiated during the charge formed by the selection of electrode 2-2.

Finally, at time t4, by selecting the row electrode 2-4 by the voltage A4, the ion flow 7 passes through the passage hole 4 at the position of the row electrode 2-4, and then the ion flow 7 of the row electrode 2-1. Irradiation is performed between the charge formed by selection and the charge formed by selection of the row electrode 2-3. In this way, one line of the electrostatic charge image is formed on the recording medium 6 by sequentially selecting the row electrodes 2-1 to 2-4 while moving the recording medium 6.

In such electrostatic recording, when the central row electrode 2-2 or 2-3 is selected and a voltage pulse of "L" level is applied to this electrode, the two row electrodes sandwiching this electrode are sandwiched. (For example, if the selected row electrode is 2-2, the potentials of the row electrodes 2-1 and 2-3) become the “H” level.
However, when the row electrode 2-1 or 2-4 is selected,
Since this electrode is not sandwiched between the two row electrodes, the surrounding electric field becomes nonuniform as described above.

Therefore, dummy electrodes 5-1 and 5-2 are provided outside the row electrodes 2-1 and 2-4, and the electrodes 5-1 and 5- are provided.
Voltages C1 and C2 having the same potential as the potential of the row electrode (“H” level of the voltage pulses A1 to A4) when the passage of the ion flow 7 is blocked are applied to 2. Thereby, the row electrode 2-
When 1 is selected, this electrode is sandwiched between the "H" level row electrode 2-2 and the dummy electrode 5-1, and the symmetry of the surrounding electric field is maintained. Similarly, when the row electrode 2-4 is selected, this electrode is the "H" level row electrode 2-3.
Since it is sandwiched between the dummy electrodes 5-2, the symmetry of the surrounding electric field is maintained.

Accordingly, in any of the row electrodes 2-1 to 2-4, the symmetry of the electric fields on both sides of the electrodes is maintained, so that the ion flow 7 passing through the ion flow passage hole 4 is It travels straight toward the recording medium 6 perpendicularly to the ion flow control plate without being deflected in the direction of the right angle. In this way, the pixels of the charge image formed on the recording medium 6 are formed at accurate positions without shifting from the predetermined positions, and an image without recording unevenness is obtained.

As an example of the structure of the ion flow control plate, assuming a recording head having a four-row structure with a resolution of 300 DPI, polyimide or the like having a thickness of about 50 to 200 μm is used as the insulating substrate 1, and the electrode 2-1. ~ 2-4, 3-1 ~
As the 3-n, 5-1, 5-2, a copper pattern having a thickness of about 5 to 30 μm may be used. The width of the row electrodes 2-1 to 2-4 is about 200 to 400 μm, and the pitch between the row electrodes is 3
The width of the column electrodes 3-1 to 3-n is about 2 to 200 μm.
The pitch between the column electrodes is about 340.
μm, the size of the ion flow passage hole 4 is 100 to 200 in diameter.
μm. Of course, any other value may be used.

The distance between the row electrodes and the dummy electrodes is the same as the pitch between the row electrodes. Then, the width of the dummy electrode is preferably set to be equal to or more than the interval (for example, 1 mm) between the ion flow control plate and the recording medium 6 with the width of the row electrode being substantially the minimum value. It is desirable that the dummy electrodes 5-1 and 5-2 have a large width because a plurality of row electrodes are present inside the electrodes 2-1 and 2-4. -2
This is because it is better to match the conditions with.

In the present embodiment, the case where there are four row electrodes has been described, but the same effect can be obtained if there are two or more row electrodes. Further, in the present embodiment, the row electrodes are arranged closer to the recording medium 6, but this arrangement may be reversed to arrange the column electrodes closer to the medium 6. In this case, the voltage applied to the row electrode and the column electrode needs to be changed from that of the present embodiment, but the voltage applied to the dummy electrode is the same as that of the row electrode when blocking the passage of the ion current as in the present embodiment. The same potential should be set.

In the present embodiment, the dummy electrode 5-
Voltages C1 and C2 having the same potential (“H” level) as the row electrode when blocking the passage of the ion current 7 are always applied to 1 and 5-2, but at least the row electrode 2-1 or 2-4. While the ion flow 7 is passing through the passage hole 4 at the position (that is, the voltage A
1 or A4 may be applied with the voltage (“H” level) of the above potential only during the “L” level. As a specific method of applying such a voltage, for example, the row electrode 2
Any of the voltages applied to −2 to 2-4 is applied to the dummy electrode 5-1 as the voltage C1, and any of the voltages applied to the row electrodes 2-1 to 2-3 is applied to the dummy electrode 5-2. May be given to.

Further, in this embodiment, the row electrodes 2-1 and 2-2 are provided.
Although only -4 is targeted, the deflection of the ion current similarly occurs in the column electrodes 3-1 and 3-n at both ends. To make this ion flow go straight, the column electrode 3-
A dummy electrode parallel to the column electrode is provided outside 1, 3-n, and the voltage range applied to the column electrode on the dummy electrode (range from "H" level to "L" level of voltage pulses B1 and B2) The internal potential should be given. By applying such a voltage, the same effect can be obtained even for the column electrode whose potential constantly changes according to the recorded information.

[0027]

According to the present invention, by providing the dummy electrodes with the same potential as the row electrodes when blocking the passage of the ion current, the symmetry of the electric field around the row electrodes located at both ends is maintained. This means that the ion flow passing through the ion flow passage holes goes straight without being deflected in the direction perpendicular to the row electrodes, so that the pixel of the electrostatic charge image can be formed at the correct position without shifting from the desired position. It is possible to obtain an image without recording unevenness.

Further, by applying a potential within the voltage range applied to the column electrodes to the dummy electrodes, the symmetry of the electric field around the column electrodes located at both ends is improved, so that the ion current passage holes are Since the passing ion flow goes straight without being deflected in the direction perpendicular to the column electrodes, the pixels of the electrostatic charge image can be formed at the correct position without shifting from the desired position, and an image without recording unevenness can be obtained. You can

[Brief description of drawings]

FIG. 1 is a plan view of a recording head according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II of FIG. 1;

3 is a timing chart showing a voltage waveform applied to each electrode of the recording head of FIG.

FIG. 4 is a diagram showing a principle of controlling an ion flow.

FIG. 5 is a plan view of a conventional recording head.

6 is a cross-sectional view taken along line I-I of FIG.

[Explanation of symbols]

1 ... Insulator substrate, 2-1 to 2-4 ... Row electrodes, 3-1 to 3
-N ... column electrode, 4 ... ion flow passage hole, 5-1, 5-2 ...
Dummy electrode, 6 ... Recording medium, 7 ... Ion flow.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masataka Ota 1-3-3 Gotenyama, Musashino-shi, Tokyo Christal Park Building NTT Advanced Technology Co., Ltd. (72) Inventor Masaru Ozawa Shinjuku-ku, Tokyo Nishi-Shinjuku 3-19-2 Nippon Telegraph and Telephone Corporation (72) Inventor Masashi Fujita 3--19-3 Nishi-Shinjuku, Shinjuku-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation

Claims (2)

[Claims] 1. An ion generation source and an ion flow control plate for controlling the flow of ions, wherein the recording medium is irradiated with the ion flow emitted from the ion generation source through the ion flow control plate to charge the recording medium. In the recording head for forming an image, the ion flow control plate is provided with an insulating substrate arranged to face the recording medium, and for selecting a recording position formed on the first surface of the insulating substrate. A plurality of row electrodes for receiving the voltage of the input voltage, and a plurality of row electrodes for inputting the voltage according to the recorded information formed on the second surface of the insulating substrate so as to intersect the row electrodes with the insulating substrate interposed therebetween. Column electrodes, and row electrodes, column electrodes and insulator substrate formed through
An ion flow passage hole for passing an ion flow, and a dummy electrode formed in parallel to the two row electrodes located at both ends of the plurality of row electrodes, the dummy electrodes being formed in parallel with the electrode. A recording head characterized in that a dummy electrode is applied with the same potential as a row electrode when blocking passage of an ion stream. 2. An ion generation source and an ion flow control plate for controlling the flow of ions, wherein the recording medium is irradiated with the ion flow emitted from the ion generation source through the ion flow control plate to charge the recording medium. In the recording head for forming an image, the ion flow control plate is provided with an insulating substrate arranged to face the recording medium, and for selecting a recording position formed on the first surface of the insulating substrate. A plurality of row electrodes for receiving the voltage of the input voltage, and a plurality of row electrodes for inputting the voltage according to the recorded information formed on the second surface of the insulating substrate so as to intersect the row electrodes with the insulating substrate interposed therebetween. Column electrodes, and row electrodes, column electrodes and insulator substrate formed through
An ion flow passage hole for passing an ion flow, and a dummy electrode formed in parallel to the two column electrodes positioned at both ends of the plurality of column electrodes, the dummy electrodes being formed in parallel with the electrode. A recording head characterized in that a potential within a voltage range applied to a column electrode is applied to a dummy electrode.