JPS6016352B2 - 2D recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-dimensional recording method using an electrostatic recording method or a cathode ray tube method. The present invention relates to a two-dimensional recording method in which a bias is applied to the continuous pixel bits to increase the recording strength when there is a risk of occurrence of recording omissions or omissions.

An example of image formation in the electrostatic recording method using multi-needle electrodes is shown in FIG.

Normally, main scanning in the direction of arrow A is performed by an electric signal applied to a multi-needle electrode, and sub-scanning in the direction of arrow B is performed by paper feeding. In this case, main scanning methods include sequential scanning for each bit and block scanning for scanning several bits at a time, but the following drawbacks are common to both methods. Image formation using an electrostatic recording method using multi-needle recording electrodes involves applying a voltage to the electrode needles and charging the recording paper or recording medium by discharge to obtain an electrostatic latent image. When the pixels in the main scanning direction (blind direction) form a continuous line with two or more bits as in the seventh row, the electric field applied to the recording needle electrode is Because of the overlap, the state of charge on the recording medium such as paper also has a distant pattern corresponding to the length of the tangent line, as shown in Figure B, and a clear horizontal line with no omissions is printed. When forming a minimum pixel of 1 bit in the main scanning direction (horizontal direction) (1st, 1st, 4th to 6th digits in Figure 1), the electric field applied to the recording needle electrode is A single pulse is generated as shown in Figure A, and the amount of charge charged on the recording medium and the charged area are small and small as shown in Figure B. Therefore, depending on the main scanning speed or the value of the voltage applied to the recording needle electrode, due to the electric field distribution, the discharge under the recording needle electrode may be insufficient, or in extreme cases, recording may not be complete. Sometimes I miss something. In other words, when printing a single line in the vertical direction (sub-scanning direction), that line becomes difficult to print.
Part or all of the information tends to be missing, which causes the overall image quality to deteriorate or to be misread. For example, when printing "earth" as shown in Figure 1,
It can be seen that if the top of the vertical line is missing, it becomes ``ko'', and if all the vertical lines are missing, it becomes ``two''. In order to improve the drawbacks of the prior art described above, the present invention provides that when vertical lines are printed, that is, when the number of consecutive pixel bits in the main scanning direction (horizontal direction) is less than 1 or some other predetermined number, The purpose is to apply a bias to the pixel pit signal to strengthen it, ensure the start of discharge there, and secure the minimum required amount of charge to ensure printing of vertical lines.

FIG. 4 is a block diagram of main parts of a two-dimensional recording apparatus suitable for carrying out the method of the present invention, and FIG. 5 is a timing chart illustrating its operation.

1 is a first shift register to which the image signal Vd is input via the terminal 11; 2 is a second shift register to which the output SI is input; 3 is the image signal Vd and each output SI of the first and second shift registers; 4 is triggered by the output SI of the first shift register, and outputs the high voltage EH as its output E to the recording needle electrode ( 5 is a bias application circuit for superimposing and outputting the bias voltage EB on the high voltage E law under the control of the output SG of the decoder 3; C is the input from the terminal 12; A clock is used to shift the first and second shift registers.

It is assumed that the image signals and clocks supplied to the terminals 11 and 12 are as shown in Vd and C of FIG. 5, respectively. In other words, clock 3 of the image signal currently being sent
, 4 and 7 to 9 have a certain degree of spread in the main scanning direction (horizontal direction);
The one corresponding to the above has a minimum pixel spread of one bit in the main scanning direction, and as described above, there is a risk of incomplete recording or recording omission. Since the contents of the first and second shift registers 2 are shifted by one digit by the clock C, their outputs are as shown in FIG. 5 SI and S2, respectively. As can be seen from these waveform diagrams, the fact that the image signal has a minimum spread of 1 pixel bit in the main scanning direction means that there is no image signal before or after it (immediately or immediately before the beginning or end). . Therefore, the output SI of the first shift register at the moment when each input [Vd-SI-S2] to the decoder 3 becomes [0-1-0] is the minimum value that exists independently and not consecutively. It can be determined that each pixel is 1 bit. Therefore, shift register 1
The output SI of the decoder 3 is adopted as the image signal to be recorded, which triggers the high voltage drive circuit 4 to apply a high voltage to the recording needle electrode, and further energizes the bias application circuit when the output SG of the decoder 3 is present. Bias E on the high voltage
If B is superimposed, the voltage waveform actually applied to the recording needle electrode will become as shown in FIG. 5E. In other words, when the image signal has a spread of at least one pixel bit in the main scanning direction, the voltage applied to the recording needle electrode is increased, which causes a discharge of sufficient intensity to charge a predetermined amount of charge. Therefore, there is no fear of incomplete recording or missing records, and complete and high-quality recording is always performed.
In the above, when the number of continuous pixel bits in the main scanning direction (horizontal direction) is 2 or more, the normal high voltage EH is applied to the recording needle, and only when the number of consecutive pixel bits is 1, the bias voltage EB is superimposed. The number threshold is not limited to 1, but may be 2 or more.

Furthermore, in addition to multi-needle electrode type electrostatic recording, in the case of cathode ray tube (so-called recording tube, optical fiber tube, etc.) type where main scanning is performed by electron beam deflection, it is possible to superimpose a bias component on the brightness. A similar effect can be obtained, and it can generally be applied when two-dimensional recording is performed by a combination of main scanning and sub-scanning. Therefore, it is of course applicable to the cylindrical scanning type of facsimile.

[Brief explanation of drawings]

Figure 1 is a diagram showing an example of character format by electrostatic recording, Figure 2
3 and 3 are diagrams showing an example of the electric field applied to the recording needle and the charging state on the recording medium when the pixel signal in the main scanning direction is continuous and single, respectively, and FIG. FIG. 5 is a block diagram of one embodiment of the present invention, and FIG. 5 is a time chart thereof. 1, 2...shift register, 3...7 coder, 4...
...High voltage drive circuit, 5.../bias application circuit, EB...bias voltage. Figure *2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. In a two-dimensional recording method in which two-dimensional recording is performed by main scanning and sub-scanning, and recording is performed pixel by pixel at least in the main scanning direction, the number of consecutive pixel signals in the main scanning direction is less than a predetermined value. A two-dimensional recording method characterized by adding a bias signal that strengthens the pixel signal to the pixel signal and performing recording.