JPH0567430B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for performing gradation recording by controlling the ion beam diameter in a recording method by controlling the ion flow.

[Prior art]

Conventionally, methods for recording gradation by controlling ion flow include a pulse width control method with a pulse width corresponding to the recording signal, and a voltage control method in which a voltage of a magnitude corresponding to the recording signal is applied to the aperture electrode. There is.

The former method has the advantage of being easy to implement with a digital circuit to control the pulse width;
When considering the point of developing the formed electrostatic latent image, there is a drawback that gradation reproducibility is not good. In addition, the latter method has the advantage of good gradation reproducibility because the ion beam diameter is controlled by controlling the voltage, but it requires a voltage control circuit for each aperture electrode. The drawback was that the system was complicated and expensive.

A method that eliminates both of these drawbacks is to apply a voltage to the aperture electrode that changes at the same period as the recording period, and turn this voltage on and off with a pulse width that corresponds to the recording signal. One possible method is to record by modulating the beam diameter, but in this case, the changing voltage is turned on and off.
The drawback is that it is difficult to turn it off due to the circuit configuration.

[Summary of the invention]

In order to eliminate these drawbacks, this invention turns on and off a changing voltage that fluctuates at the same period as the recording period.
It is added to the control electrode on the side that does not have OFF control. The present invention will be explained in detail below with reference to the drawings.

[Embodiments of the invention]

FIG. 1 is a diagram showing one embodiment of the present invention, and FIGS. 2a and 2b are diagrams showing examples of waveforms used in the embodiment of FIG. 1. In Figure 1, 1 is a shield case, 2 is a corona wire, 3 is an upper control electrode, 4 is a lower control electrode, 5 is a dielectric recording medium, 6 is a conductive substrate, and Vc
is a corona voltage, Vs is a shield voltage, V ₁ is a variable voltage applied to the corona wire side, that is, the upper control electrode 3, and V ₂ is a pulse voltage applied to the recording medium side, that is, the lower control electrode 4.

To operate this, a variable voltage V ₁ as shown in FIG. A pulse voltage V ₂ as shown in FIG. 2b having a width corresponding to the density is applied, and the ion flow is passed only when there is an ON pulse of the pulse voltage V ₂ to form an electrostatic latent image on the recording medium 5. Form.

In this way, since the method is to control both the voltages V ₁ and V ₂ of the upper and lower control electrodes 3 and 4,
Timing of ON/OFF signals applied as pulse voltage V ₂ , pulse width of ON signal, and changing voltage
Depending on the waveform of the voltage applied as V ₁ , it is possible to set the potential difference between the upper and lower control electrodes 3 and 4 during ion flow passage, and therefore the temporal change in electric field strength, to various types.

If we apply voltages V ₁ and V ₂ with waveforms as shown in Figure 2 a and b, when the ON pulse of pulse voltage V ₂ is short, the potential difference between both control electrodes 3 and 4 will be relatively small. Since the ion current is passed through the ion flow, the ion flow is narrowed and a small and sharp electrostatic image is formed.
At the end of the pulse, the ion flux is passed while the potential difference between both control electrodes 3 and 4 is relatively large, so the ion flux diameter becomes large, and an electrostatic image of a large area can be obtained in a short time. be able to.

In the above case, a constant potential is applied to the control electrode to which ON pulses are not applied, so that the desired narrowest ion flux diameter can be obtained when ON pulses are applied to the other control electrode. Even with only this,
The diameter of the ion flux gradually expands due to the Crohn repulsion caused by the electrostatic charge on the recording medium 5, so the recording dot diameter can be changed by changing the ON pulse width, but in this case, it is necessary to record dots with a large area. Since an ion flow with a small flux diameter is used when recording, the ON pulse width must be made considerably large in order to obtain a sufficient recording density, which is undesirable as it slows down the recording speed.

In addition, we decided to apply a constant potential to the control electrode to which ON pulses are not applied so that the desired thickest ion flux diameter can be obtained when ON pulses are applied to the other control electrode. For example, it is possible to perform gradation recording by changing the image density of recording dots by changing the charge density of the electrostatic image obtained by changing the ON pulse width. An analog developing section capable of reproducing an image density proportional to is required, which is undesirable in terms of stability and the like.

In contrast, according to the present invention, a small electrostatic image dot is formed by a narrow ion flux diameter, and a large electrostatic image dot is formed by a large ion flux diameter, so even when trying to obtain a large dot, the recording pulse is The width may be relatively small, and the resulting electrostatic image dots have a nearly constant charge density and differ only in size, so analog development is not necessary and digital binary development is sufficient, and is stable. Excellent in sex.

Note that in the above embodiment, a case was explained in which a periodically fluctuating variable voltage V ₁ was applied to the upper control electrode 3 and a pulse voltage V ₂ was applied to the lower control electrode 4, but these combinations could be reversed and applied to the upper control electrode 3. The same effect can be obtained by applying the pulse voltage V ₂ to the variable voltage V ₁ to the lower control electrode 4.

Next, it will be explained with reference to FIGS. 3a to 3c that the ion beam diameter can be controlled by the magnitude of the voltage applied to the upper and lower control electrodes 3 and 4. This is a computer simulation result of the ion trajectory.

Figures 3a, b, and c show changes in the ion beam diameter due to voltage changes applied to the upper and lower control electrodes 3 and 4 shown in Figure 1, and only half from the center of the ion flow control hole is shown. There is. The ion beam diameter can be controlled by voltages applied to both control electrodes 3 and 4, as shown in FIGS. 3a to 3c.

That is, in Figure 3 a, b, c, E ₁ , E ₂ , E ₃
respectively indicate an electric field in the vicinity of the upper control electrode 3, an electric field between the upper control electrode 3 and the lower control electrode 4, and an electric field in the vicinity of the lower control electrode 4.

FIG. 3a shows the case where E ₂ /E ₁ =−0.5 and E ₃ /E ₁ =4, and the ion flow 10A cannot pass through the ion flow control hole, so no recording is performed.

FIG. 3b shows the case where E ₂ /E ₁ =0 and E ₃ /E ₁ =4, and recording is performed by a narrow ion stream 10B.

FIG. 3c shows the case where E ₂ /E ₁ =2 and E ₃ /E ₁ =4, and recording is performed with a thick ion flow 10C.

Furthermore, the waveform of the changing voltage V ₁ changes not only linearly as shown in Figure 2 a, but also in a curved line that is convex or concave upward as shown in Figures 4 a and b. Other voltage waveforms can also be used.

In the embodiment shown in FIG. 1, a variable voltage V ₁ is applied to the upper control electrode 3. In this case, since the potential difference between the corona wire 2 and the upper control electrode 3 changes periodically, the ion flow also changes accordingly. That is, when the value of the changing voltage V ₁ is small, the potential difference with the corona wire 2 is large, so the ion flow density is also large, and therefore the pulse voltage
Even if the V ₂ ON pulse width is small, recording above the threshold value is possible.

〔Effect of the invention〕

As explained above, the present invention applies a pulse voltage to one of the upper and lower control electrodes to apply the ion flux diameter during the time when the ion flow is passing through the other control electrode. Since the voltage can be changed arbitrarily over time using a changing voltage that fluctuates with the recording cycle, it has excellent gradation reproducibility with a simple circuit.
This has the advantage that recording can be performed at a high recording speed.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention;
Figures 2a and b are diagrams showing examples of voltage waveforms used in the embodiment of Figure 1, Figures 3a to c are diagrams showing examples of controlling the ion flux diameter, and Figures 4a and b are diagrams showing examples of the control of the ion flux diameter. FIG. 7 is a waveform chart showing other examples of varying voltages. In the figure, 1 is a shield case, 2 is a corona wire, 3 is an upper control electrode, 4 is a lower control electrode, 5 is a recording medium, 6 is a conductor substrate, 10A to 10C are ion currents, Vc is a corona voltage, and Vs is a shield Voltage, V ₁
is the changing voltage and _V2 is the pulse voltage.

Claims (1)

[Claims] 1. In a recording method in which ion flow is controlled by an upper control electrode and a lower control electrode, a variable voltage that fluctuates at the same period as the recording period is applied to one of the control electrodes, and a pulse width corresponding to the recording signal is applied to the other control electrode. A gradation recording method characterized in that recording is performed by modulating the ion flux diameter of the ion flow by applying a pulse voltage of.