JPH02102070A - Ion flow electrostatic recorder - Google Patents

Abstract

PURPOSE:To control fine latent image potential and to express a sufficient halftone by dividing a control electrode into a predetermined number of control unit electrode groups, and controlling to apply a voltage with the group as one dot. CONSTITUTION:Two adjacent control electrodes 17(k), 17(k+1) (k = 1, 3, 5,...) are used as a set to form a control unit electrode group. An average circuit 33 {(k+1)/2} for calculating the average value of gradation data to be supplied from a host system (office computer, etc.) for the electrodes 17(k), 17(k+1) is provided, and the circuit 33 {(k+1)/2} is composed, for example, of a calculating ROM. A converter 31(k), 31(k+1) for outputting a voltage responsive to input data is connected to the electrodes 17(k), 17(k+1), average data from the circuit 33 {(k+1)/2} are inputted in parallel to the converters 31(k), 31(k+1), and the group is gradation-controlled corresponding to one dot.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an ion flow electrostatic recording device that forms an electrostatic latent image on a recording medium using ions, and more specifically, it relates to an ion flow electrostatic recording device that forms an electrostatic latent image on a recording medium using ions. It has an ion generator that forms an ion flow, and a plurality of control electrodes arranged corresponding to the printed dots in the ion flow path from the ion generator to the recording medium. The present invention relates to an ion flow electrostatic recording device which forms an electrostatic latent image on a recording medium by controlling the flow of ions dot by dot to a recording medium using an electrostatic field.

[Prior Art] Conventionally, the structure of a head portion in this type of ion current electrostatic recording device is as shown in FIG. 5, for example.

In the figure, an ion generator 310 is configured by a discharge wire 11 and a shield 12 surrounding it. The shield 12 is made of stainless steel or the like, and has longitudinally parallel slits 13 and 14 formed on its lower and upper surfaces. A substrate 16 is fixed to the lower part of the shield 12 via a spacer 15 made of an insulating material, and on this substrate 16 there are slits corresponding to printed dots facing the slits 13 formed in the shield 12. Control electrode 1
7 are sequentially arranged at a predetermined density (for example, 8 pieces/m). An image control voltage is applied from the drive circuit 20 to each control electrode 17. Furthermore,
FIG. 6 is a Vl-VT sectional view of the head portion shown in FIG. 5, and as shown in FIG.
A head portion having the above-described structure is placed near a recording body 22 formed of a dielectric material or the like in which a shield 12 is grounded and a power source 21 is connected to the discharge wire 11. Further, a power source 26 having an output voltage characteristic of opposite polarity to the voltage applied to the discharge wire 11 is connected to the counter electrode 24 .

In such a structure, the slit 1 is inserted as shown by the arrow 27.
Air introduced into the shield 12 from the slit 12
The liquid then flows out through the gap between the shield 12 and the substrate 16 on which the control electrodes 17 are arranged, and reaches the recording medium 22 as indicated by an arrow 28. Then, positive ions 25 generated by applying a voltage to the discharge wire 11 move along with the air flow and reach the recording medium 22 . As a result, a uniform ion flow is formed on the recording medium 22. When a voltage is applied to the control electrode 17 with this ion flow formed, an electrostatic field is formed between the control electrode 17 and the shield 12, and this electrostatic field blocks the ion flow at that part. Ru.

Therefore, in this type of recording device, the ion flow reaching the recording body 22 is controlled dot by dot by controlling the voltage application to each control electrode 17 based on the image information, and the ion flow corresponding to the image information is placed on the recording body 22. A static N latent image is formed. Note that after this latent image is formed, an image corresponding to the electrostatic latent image is reproduced on, for example, a recording sheet by going through steps such as development and transfer.

Furthermore, the applicant has proposed a system in which the potential of the latent image of each dot formed on the recording medium 22 is controlled by controlling the voltage value applied to the control electrode 17, thereby controlling the gradation of the image obtained. (Japanese Unexamined Patent Publication No. 60-284236
(see publication).

That is, as shown in FIG. 7, each control till electrode 17 (1
) to 17(■), a conversion circuit 31 (1) that outputs a voltage according to the gradation data (2 pit data in the case of 4 gradations)
~31 (m) is connected, each control m + electrode 17 (1) ~
17 (111), an image control voltage corresponding to the gradation data is applied. In this case, an electrostatic field with an intensity corresponding to the applied voltage is formed in each control tl electrode 17(1) to 171n), and the flow of ions reaching the recording medium 22 is controlled for each dot according to the electric field strength. . As a result, an electrostatic latent image is formed on the surface of the recording medium 22 for each dot, with a potential corresponding to the gradation data.

[Problems to be Solved by the Invention] By the way, in the conventional ion flow electrostatic recording device that performs gradation control by controlling the voltage applied to each control electrode as described above, sufficient gradation expression cannot be achieved. Can not.

This is because the latent image potential of each dot, which is determined by the flow rate of ions reaching the recording medium, becomes unstable due to the influence of the adjacent latent image potential (between the arriving ion flows). Specifically, in dots adjacent to dots with a high latent image potential, the ion flow is repelled by the high temperature image potential, and the latent image potential tends to be lower than the control target potential.

For example, taking 4-gradation expression (0, 1, 2, 3) as an example,
As shown in FIG.
The latent image potential of the dot (2) corresponding to the gradation level "1" is influenced by the latent image potential (2) of the dot (2) corresponding to the gradation level "2" and becomes lower than the control target potential V1. Furthermore, as shown in FIG.
When reproducing 1 "3", the latent image potentials of both dots 1 and 2 are influenced by the high latent image potentials of the adjacent dots, and are lower than the control target potentials V2 and Vl. Even if an attempt is made to reproduce the same 1'' tone like the dots 2 and 2 shown in FIGS. 8 and 9, the latent m potential will vary depending on the potential state of the adjacent dots.

Therefore, an object of the present invention is to ensure that the latent image potential of each dot does not deviate significantly from the control target potential, no matter what the latent image potential state of adjacent dots is.

[Means for Solving the Problems] The present invention includes an ion generator 2 that forms a uniform ion flow with respect to the recording medium 1, and a printed dot in the ion flow path from the ion generator 2 to the recording medium 1. A plurality of control electrodes 3 (11) to 3 (In) are arranged corresponding to The ion current electrostatic recording device is based on an ion current electrostatic recording device in which the flow rate is controlled dot by dot to form an electrostatic latent image on the recording medium 1. The technical means is to divide control electrodes every predetermined number n into control unit electrode groups (
3(i1),, 3(i2),..., 3(in))
(+-1, 2, ..., -), and control unit electrode groups (3 (if), 3 (i2).

-, 3 (in)) (i-1, 2, . . . , ts), voltage application control means 4 applies a common image control voltage to each l+ control electrode (i) (i=1.2...・、
m).

Especially each! 11 m %Image independently for i pole! The voltage application control means 4(i) is of the type that provides gradation data that is the basis of the control voltage, and the voltage application control means 4(i) has the control electrodes (3(i1), 3(i2),..., 3() in))
The configuration includes an applied voltage determining means that determines a common image control voltage based on gradation data provided to the two images.

With such a configuration, the algorithm for determining gradation data in the host device that controls the printing apparatus does not require any change from the conventional algorithm, and the printing apparatus becomes a versatile printing apparatus. In this case, the applied voltage determining means determines, for example, a common image control voltage corresponding to the average value of gradation data provided to each control electrode.

Further, in addition to the above-mentioned aspect, the voltage application control means 4(i) is controlled by a control unit electrode group (3(i1),) from a host device.

3 (i2),..., 3(in)), and a part of that function is transferred to the host device so that the same gradation data is sent to each control electrode according to the gradation data. It may also be configured.

"Action J Each unit control electrode group (3 (i1), 3 (i2), ・
. . 3 (in)), a common image control voltage is applied by the voltage application control means 4(i). As a result, each unit control electrode group (3(i1),, 3(i2),...,3
(in)) on the recording medium 1 of the dot group corresponding to the latency tI
The i potential is controlled by the same IIA potential. Therefore,
Tone reproduction is performed in dot group units.

Particularly, in the case of the type in which the basic gradation data of the machine control voltage is provided independently to each control electrode, the applied voltage determination means is based on the gradation data for each control electrode of the unit control electrode group. determines a common image control 111 voltage, and the determined common control voltage is applied to each control electrode 3 of the unit control electrode group handled by the voltage application IIJ control means 1).
(i1), 3 (i2), . . . 3 (in).

[Example] Embodiments of the present invention will be described below based on the drawings.

The overall structure is similar to the conventional recording device shown in FIGS. 5 and 6. In such a recording apparatus, the configuration of a voltage application system to each control electrode is shown in FIG. 2, for example.

In the figure, adjacent control electrodes 17 (k).

17 (k+1) (k·1, 3, 5, . . . ) are arranged in pairs to form a unit electrode group υ71M1.

One 1IJI 11 unit electrode group (17(k), 17
(k+1) ), each control electrode 17 (k)
, 17 (k+1) is provided with an averaging circuit 33 ((b+t)/25) that calculates the average value of gradation data provided from a host device (office computer, etc.). (k@)/2X is configured by a calculation ROM, for example. Each control tll electrode 17 (k) 17
(k+1) is connected to a conversion circuit 31 (k), 3Hk÷1) that outputs a voltage according to the input data, and the averaged data from the averaging circuit 33 (αf%) is applied to each conversion circuit 31 (k ), 31 (k+1) are input in parallel.

With the above configuration, each control unit electrode group can be
Gradation control will be performed accordingly.

For example, if we take a 4-gradation expression (0, 1, 2, 3) as an example, as shown in Figure 8, the gradation data provided by the host device for consecutive dots is 0. ″″゛2″
When "11+117011", the dots corresponding to one control unit electrode group are provided with gradation data "2" and "1".
Two controls 11 are performed to obtain a gradation with an average value of
A voltage is applied to the electrodes, and the potential of the latent image of the dots (2) and (2) formed on the recording medium 22 is controlled to target v1. These potentials V+ and r have an intermediate value between the potential V1 corresponding to the gradation "1'°" and the potential V2 corresponding to the gradation "2".As a result of such control, the dots The latent image potential is controlled to approximately the target potential v1s because the adjacent dots are not at a high potential.Also, as shown in FIG. When becomes "3""2""1""3", in this case as well, the dot ■■ has a gradation of 111.
511, voltage is applied to the two corresponding control I electrodes, and the latent m potential is controlled with vt'i as the target. In this case, the dots adjacent to the dots ■■ have a high potential, but since the target potential is V+ and the latent image area becomes larger (twice as much as before), the shadow νblue of the adjacent dots is reflected in the periphery. Even if it is used to some extent, its influence is small overall, and the potential of the latent image actually formed for the dots 2 and 2 is controlled to approximately the target potential V 1.5.

In this way, if tone control is performed by associating the control middle N-pole group composed of two control electrodes with one dot, the latent image potential formed on the recording medium 22 of the dot will change. This makes it difficult to be influenced by the latent image potential of adjacent dots, making it easier to control the latent image potential to the target potential. Therefore, more accurate gradation υ control is possible, and the gradation of the reproduced image can be improved.

In the above embodiment, a control unit electrode group is composed of two adjacent control electrodes, but the present invention is not limited to this.
[More Controls] The main electrodes may constitute a control unit electrode group.

In addition, the common image control voltage applied to each control electrode is
It is not limited to the voltage value corresponding to the average value of the gradation data provided to the electrodes constituting the control unit electrode group, but may be determined as appropriate according to the gradation pattern provided to the control unit electrode group. It will be done.

Furthermore, when the number of electrodes constituting the control unit electrode group is increased, the resolution of the reproduced image inevitably decreases, but the number of electrodes constituting the control unit electrode group depends on the characteristics of the reproduced image, for example, the resolution It is determined as appropriate depending on the type of image (such as a character image) or the type of image that requires gradation (such as a half-tone image).

For example, when reproducing a character image, each control electrode is controlled as one dot, and when reproducing an intermediate representation image, a control unit electrode group consisting of two control electrodes is used as in the above embodiment. The control lB may be switched depending on the image to be reproduced so that the control is performed as one dot.

In the above embodiment, the common image control voltage is determined based on the gradation data provided from the host device using the same algorithm as before, but the gradation data is determined for each control unit electrode group in the host device. , voltage application to each control 11 electrode may be controlled based on the gradation data.

[Effects of the Invention] As explained above, according to the present invention, the control electrodes are divided into a predetermined number of control unit electrode groups, and voltage application is controlled using each control unit electrode group as one dot. The latent image potential of each dot will not deviate significantly from the control target potential, no matter what the state of the latent image potential of the adjacent dots. Therefore, it becomes possible to more finely control the latent image potential and achieve sufficient gradation expression.

In addition, when determining the common image control voltage for the constituent N poles based on the tone data provided to the constituent electrodes of each control intermediate electrode group, the tone data is determined according to the conventional algorithm. It becomes possible to connect directly to the determined host device, making it possible to realize a recording device with higher versatility.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of the present invention, FIG. 12 is a diagram showing a configuration example of a voltage application system to each control m+ electrode in the ion flow electrostatic recording apparatus according to the present invention, and FIGS. 3 and 4 are Figure 2 is a diagram showing the relationship between gradation data and latent image potential formed in the apparatus shown in the apparatus, and Figures 5 and 6 are examples of the overall configuration mainly related to the head section of the ion current electrostatic recording apparatus. 7 is a diagram showing an example of the configuration of a voltage application system to each control electrode in a conventional ion flow electrostatic recording device, and FIGS. FIG. 3 is a diagram showing the relationship between tone data and potential of a latent image formed. [Explanation of symbols] 1.22... Recording body 2.10... Ion generator 3 (11) ~3 (n1),, 17 (1) ~
17 (1)...Control electrode

Claims (2)

[Claims] (1) An ion generator (2) that forms a uniform ion flow to the recording medium (1), and an ion flow path from the ion generator (2) to the recording medium (1) that corresponds to the printed dots. A plurality of control electrodes arranged as {3
(11) to 3(1n)...}, and the ion flow rate reaching the recording medium (1) is controlled for each dot by an electrostatic field formed by applying an image control voltage to the control electrode. In an ion flow electrostatic recording device that forms an electrostatic latent image, control electrodes for each predetermined number n are grouped into control unit electrode groups {3(i1),
3(i2),...,3(in)}(i=1,2,...,m)
The control unit electrode group {3(i1), 3(i2),..., 3(i
n)}(i=1,2,...,m), voltage application control means {4(
i)} (i=1, 2,..., m). (2) In the ion flow electrostatic recording device according to claim 1, wherein gradation data serving as the basis of the image control voltage is independently supplied to each control electrode, the voltage application control means {4(i)} It has an applied voltage determining means that determines a common image control voltage based on gradation data provided to each control electrode {3(i1), 3(i2), ..., 3(in)} in charge. An ion current electrostatic recording device characterized by: