JPS628063B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic recording device suitable for facsimile and the like.

In an electrostatic recording device such as a facsimile, it is necessary to record an image signal by appropriately switching the recording scanning line density.

Therefore, in conventional electrostatic recording devices, while performing main scanning using a recording head in which multiple recording electrodes are arranged in the sub-scanning direction according to the finest scanning line density, the recording scanning line density is switched. in case of,
The scanning line density in the sub-scanning direction was also controlled by changing the paper feed.

On the other hand, the electrostatic recording device proposed by the applicant (patent application
151731), main scanning is performed using a recording head in which multiple recording electrodes are arranged in the sub-scanning direction according to the finest scanning line density, and when switching the recording scanning line density, A possible method is to select and drive electrodes arranged in a signal corresponding to the scanning line density to switch the scanning line density and record an image signal.

However, this method has the drawback that the number of electrode drive circuits increases, making the recording device expensive.The applicant has first developed a method suitable for recording by switching the scanning line density to eliminate these drawbacks. A recording head was proposed. (Refer to Japanese Patent Application No. 57268 of 1973) Regarding this recording head, please refer to Fig. 1.
I'll explain it in a little more detail now.

Figure 1 shows a recording scanning line density of 8 line/mm.
This is a schematic configuration diagram of the recording head when recording image signals by switching to 2 steps of 4 lines/mm.
1 to S32 are recording electrodes for recording at a scanning line density of 4 lines/mm. Each electrode S1 to S32
are the odd-numbered electrodes S1, S3...
...S31 and even numbered electrodes S2, S4...S32
The electrodes are arranged in two rows of 16 electrodes each. Each column is spaced apart by l in the main scanning direction, and
In the sub-scanning direction, the electrodes are arranged in a staggered manner at intervals of 4 electrodes/mm.

S01 to S032 are electrodes for recording at a scanning line density of 8 lines/mm. Each electrode S01
~S032 is also the odd numbered electrode S01, S03...S0, similar to the recording electrode with a scanning line density of 4 line/mm.
31 and even numbered electrodes S02, S04...S03
Two rows of electrodes in the sub-scanning direction of 2 are spaced apart from each other in the main-scanning direction, and each electrode is arranged in a staggered manner at an interval of 4 lines/mm in the sub-scanning direction, adjacent to the recording electrodes at a scanning line density of 4 lines/mm. Arranged. Of course, the scanning line density
2 electrodes: 4line/mm recording electrode and 8line/mm recording electrode
Instead of arranging the electrode groups in parallel in the main scanning direction as shown, they may be arranged in series in the sub-scanning direction.

By configuring the recording head as described above, the electrode drive circuit for applying image signals can be used in common whether recording at 4 lines/mm or 8 lines/mm, compared to conventional ones. Since the number of electrode drive circuits can be reduced by half compared to conventional recording heads, it has excellent functions and effects.However, if the number of electrode drive circuits could be further reduced, recording It is clear that the device will be more compact and cheaper.

The present invention has been made in view of these points, and improves the recording head electrode drive method previously proposed by the applicant, further reduces the number of electrode drive circuits, and makes it compact and inexpensive. An object of the present invention is to provide an electrostatic recording device configured as follows.

In an electrostatic recording device for a facsimile receiver that performs recording by reciprocating a recording head in the main scanning direction, in which multiple recording electrodes are arranged in the sub-scanning direction, sizes are different for each of the multiple linear density modes. , has multiple recording electrode groups in which the number of electrodes in each electrode group is approximately the same, and is arranged in multiple rows in the sub-scanning direction and in multiple rows in the main scanning direction, and according to the linear density mode specified by the transmitting side. a recording head that switches and uses each recording electrode group; a plurality of electrode drive circuits that are commonly provided to each electrode in the order in which the electrodes are arranged in the electrode array; means for selecting each of the electrode rows in the selected electrode group in accordance with main scanning of each of the recording heads, and applying image signals corresponding to each of the electrode rows to the electrode drive circuit in a time-division manner; It is characterized by consisting of.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 2 to 4.

FIG. 2 is a block diagram of the recording head for explaining the connection state to each driving circuit for driving each electrode of the recording head of FIG. 1, and the same reference numerals as in FIG. 1 indicate the same parts. The one-dot chain line and the two-dot chain line in the figure each represent that the electrodes are connected to a common drive circuit. That is, in the order of electrode arrangement in the sub-scanning direction in each electrode column arranged in the main-scanning direction, electrodes S1, S2, S01, and S02 are connected to a common row direction electrode drive circuit X1 shown in FIG. 3, and electrodes S3, S4, S03, and S04 are connected to the row direction electrode drive circuit X2. Also, electrodes S1 and S of each electrode row
3...S31, electrodes S2, S4...S32, electrodes S01, S02...S031, electrodes S02, S0
4...S032 also depends on the scanning line density.
As will be described later, common column direction electrode drive circuits Y1 and Y are used to adjust the application timing of image signals.
Connect to 2, Y3, and Y4.

FIG. 3 shows a schematic configuration diagram of an electrode drive device constructed by connecting each electrode S1 to S32, S01 to S032 on the recording head and each drive circuit X1 to X16, Y1 to Y4 in this manner. The output conductors of the row direction electrode drive circuits X1 to X16 and the column direction electrode drive circuits Y1 to Y4 constitute a matrix, and diodes D, D, and D are connected to the intersections of the matrix.
A resistor R is connected, and a recording electrode is connected to the connection point between the diode D and the resistor R.

The row direction electrode drive circuits X1 to X16 and the column direction electrode drive circuits Y1 to Y4 are each composed of the same circuit, and specifically, for example, are constructed as shown in FIG. 4.

That is, FIG. 4 shows a specific circuit configuration diagram of the row direction electrode drive circuit X1 and the column direction electrode drive circuit _Y1 . Accordingly, the output conductor x1 is brought to ground potential or left open. Further, as described later, the row electrode drive circuit Y1 receives a scanning line density switching signal a and a column selection signal c generated at a predetermined timing in consideration of the recording time.
When the electrode drive signal _e1 is output from the AND gate A1, the transistor Q3 is turned on and the output conductor Y1 is brought to a negative high potential. Then, when the output conductor Y1 is at a negative high potential and the output conductor x1 is in an open state, a negative high voltage is applied to the recording electrode S1,
Make prescribed records.

In addition, A1 to A4 in FIG. 3 are AND gates, Q1 to Q3 in FIG. 4 are transistors,
R1 and R2 are resistors, and D1 is a diode.

Next, the operation of the electrode driving device of FIG. 3 constructed as above will be explained with reference to the time chart of FIG. 5.

Now, a recording scanning line density of 4 lines/mm on the receiving side is specified according to the scanning line density when scanning is performed on the transmitting side, and a scanning line density converted signal a is sent to the electrode driving device shown in Fig. 3.
Assume that the input is

A pixel signal g of 32 pixels in the sub-scanning direction sent from the transmission side is divided into an odd-numbered pixel signal g _pdd and an even-numbered pixel signal g _eveo in the order of arrangement in the sub-scanning direction, and the odd-numbered pixel signal g _pdd is The image signals are input as image signals _g1 to _g16 to the row direction drive circuits X1 to X16 in FIG. 3 through a serial/parallel conversion circuit or a circuit such as a shift register. On the other hand, the even-numbered image signal g _eveo is temporarily
Store in memory circuit.

Image signals g ₁ - input to drive circuits X1 - X16
_g16 brings the output conductors x1 to x16 to ground potential or to an open state depending on the signal state, ie, "white level" or "black level".

At this time, the AND gate A1 selects the scanning line switching signal a and the odd-numbered picture signal g _pdd .
It is opened by the input odd column selection signal c, and applies the electrode drive signal _e1 to the column direction drive circuit Y1.

The column direction drive circuit Y1 receives an electrode drive signal e ₁ therein.
When input, the transistor Q3 becomes conductive and the output conductor y1 becomes a negative high potential. When the output conductor y1 becomes a negative high potential, a high voltage is applied to the electrode of the output conductors x1 to x16 connected to the intersection with the open output conductor according to the image signal, and a predetermined recording is performed. be exposed.

In this way, the odd row electrodes S of the recording head
1, S3...S31 completes recording corresponding to the odd-numbered picture signal g _pdd , this time the even-numbered picture signal g _eveo previously stored in the storage circuit is taken out and applied to the drive circuits X1 to X16.

In response, the even column selection signal d is applied to the AND gate A2, and the electrode drive signal _e2 is then applied to the column direction drive circuit Y2.

This even-numbered image signal g _eveo is generated by the drive signal e ₂ generated when the recording head moves by l in the main scanning direction and reaches the position where the odd-numbered image signal was previously recorded.
Even-numbered column electrodes S2, S4...S32 are even-numbered image signals g
Record compatible with _eveo .

When recording of this even-numbered image signal g _eveo is completed, image signals for the next 32 pixels are input again, and the same recording operation as described above is repeated.

Figure 5 shows this timing state.
As shown in the figure, the input image signals for 32 pixels are divided into an odd-numbered pixel signal g _pdd and an even-numbered pixel signal g _eveo , and are sequentially applied to the row direction drive circuits X1 to X16. Correspondingly, the drive signal e ₁ is applied to the column direction drive circuit Y1 at the timing shown in the figure to make the output conductor y1 a negative high potential _. Make a record. Next, after a time τc during which the recording head moves by l in the main scanning direction, the column direction drive circuit Y2 is driven by the drive signal _e2 at the timing shown in the figure, and the even numbered column electrodes S2, S4...
In S32, the even-numbered image signal g _eveo is recorded. In this way, when the recording of image signals for 32 pixels is completed by time division, the recording head moves a predetermined distance in the main scanning direction to record the image signals for the next 32 pixels. When the position is reached, i.e.
After time τd, the previous recording operation is repeated again.

The recording voltage application time widths τa and τb at this time do not necessarily need to be set equal.

The above describes the recording operation when a scanning line density of 4 lines/mm is selected, but the column direction drive circuits Y3 and Y4 are also selected for the recording operation when a scanning line density of 8 lines/mm is selected. Just 4 lines/
Since the operation is almost the same as in the case of mm, the explanation thereof will be omitted.

Since the input image signal is divided into odd-numbered image signals and even-numbered image signals and applied to predetermined odd-numbered column electrodes or even-numbered column electrodes by time division, the electrode drive circuit can handle half the number of electrodes. The number can be reduced to 16, simplifying the configuration and making it possible to configure the recording device at low cost. Furthermore, when the electrode drive device is mounted on a carriage together with the recording head, the weight of the carriage can be reduced, and the number of harnesses from the control section (not shown) to the electrode drive device can be reduced, making it reliable. can improve sexual performance.

In the above embodiment, the electrodes of the recording head are
Although an example in which two rows of electrodes are arranged corresponding to 4 lines/mm and 8 lines/mm has been described, it goes without saying that the electrode groups provided and the number of electrodes arranged can be arbitrarily designed depending on the scanning line density.

Furthermore, in the above embodiment, the odd-numbered column electrodes S1, S3
...After recording the odd-numbered picture signal g _pdd in S31, the recording head moves by l in the main scanning direction τ
Although it was explained that the even-numbered image signal g _eveo can be read by the even-numbered column electrodes S2, S4...S32 after c hours, the even-numbered image signal g eveo is recorded. , it is also possible to record image signals at intervals in the main scanning direction that are much finer than the intervals l.

For example, a fixed interval d in the main scanning direction (for example, 0.125 mm when the linear density is 8 line/mm, and 0.125 mm when the linear density is 4 line/mm).
0.25 mm), the odd-numbered column electrodes and even-numbered column electrodes are arranged in a staggered manner with a spacing l of l = nd (number of pixels recorded between l, n>1). When recording an image signal using the recording head, the odd-numbered image signal D _pdd of the input 32-bit image signal is immediately converted into parallel and applied to the row direction electrode drive circuits X1 to X16. On the other hand, the even-numbered pixel signal D _eveo may be configured such that it is once input to the delay circuit, delayed by n+1 pixels in the main scanning direction, and then converted into parallel signals and applied to the row direction electrode drive circuits X1 to X16.

In this way, as the recording head moves, the odd-numbered image signal and the delayed even-numbered image signal are alternately applied to the electrode drive circuit, and the odd-numbered column electrodes and even-numbered column electrodes are alternately driven accordingly. As a result, image signals of a predetermined 32 bits can be recorded at constant intervals d in the main scanning direction.

In an electrostatic electrode recording device for a facsimile receiver, which performs recording by reciprocating a recording head in the main scanning direction, in which multiple recording electrodes are arranged in the sub-scanning direction, the size of each recording head is different depending on the multiple linear density modes. , has multiple recording electrode groups in which the number of electrodes in each electrode group is approximately the same, and is arranged in multiple rows in the sub-scanning direction and in multiple rows in the main scanning direction, and according to the linear density mode specified by the transmitting side. a recording head that switches between each recording electrode group and uses the recording electrode group; a plurality of electrode drive circuits that are commonly provided to each electrode in the order in which the electrodes are arranged in the electrode row; means for selecting each of the electrode rows in the selected electrode group in response to main scanning of the recording head, and applying image signals corresponding to each of the electrode rows to the electrode drive circuit in a time-division manner; It is characterized by consisting of. Therefore, the number of electrode drive circuits can be reduced, and the recording apparatus can be configured compactly and at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of the recording head previously proposed by the applicant, and FIG. 2 is a schematic configuration diagram of the recording head showing the state of connection to each drive circuit when the recording head is applied to the present invention. , FIG. 3 is a schematic configuration diagram of a one-electrode driving device applied to the present invention, and FIG.
FIG. 5, a detailed partial configuration diagram thereof, is a time chart for explaining its operation. S1-S32, S01-S032... Electrode, X
1 to X16...Row direction electrode drive circuit, Y1 to Y4
... Column direction electrode drive circuit, A1 to A4 ... AND gate, R ... Resistor, D ... Diode.

Claims (1)

[Claims] 1. In an electrostatic recording device for a facsimile receiver that performs recording by reciprocating a recording head in the main scanning direction, in which a plurality of recording electrodes are arranged in the sub-scanning direction, each size is adjusted to correspond to a plurality of linear density modes. Differently, each electrode group has approximately the same number of electrodes, and has multiple recording electrode groups arranged in multiple rows in the sub-scanning direction and in multiple rows in the main scanning direction, and can be used in the linear density mode specified by the transmitter. A recording head that switches and uses each recording electrode group according to the above-mentioned linear density mode, a plurality of electrode drive circuits that are commonly provided to each electrode in the order of electrode arrangement of the electrode row, and an electrode group that corresponds to the above-mentioned linear density mode. means for selecting each of the electrode rows in the selected electrode group corresponding to the main scanning of the recording head, and applying image signals corresponding to each of the electrode rows to the electrode drive circuit in a time-division manner; An electrostatic recording device comprising: