JPS6019707B2 - Image signal recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image signal recording method for driving a large number of recording elements in blocks.

A recording method in which a large number of recording elements arranged in a line are divided into multiple blocks, and these multiple blocks are sequentially selected in a predetermined order, so that only the recording elements in the selected blocks are driven in accordance with the image signal. There is.

When this recording method is applied to electrostatic recording, for example, as shown in FIG.
2 are both turned on. In order for the transistor TR to turn on, the corresponding image signal is "black", but the transistors TR2 common to a plurality of recording electrodes in the block are applied in a predetermined order. The block signal turns on regardless of the image signal. When both transistors TR, TR2 are turned on, a necessary electric field is generated between the recording electrode and a counter electrode (not shown) due to the voltage division ratio of the resistors R, R2, and R3, and a recording operation is performed. The above-mentioned recording operation is performed by simultaneously driving all the recording electrodes in the block, and all the image signals corresponding to all the recording electrodes are "white". In this case, there is no need to perform any recording operation. However, in this type of conventional recording method, the transistors TR2 are turned on in a predetermined order, so during this period, the transistors TR. Power is consumed even if both are off. For this reason, for example, 1 line 2
In a facsimile machine that divides a 048-bit image signal into private blocks, there is a high probability that all blocks are "white", and the reality is that the power wasted during this time and the heat generated by it cannot be ignored. Ta. The present invention has been made in view of the above points, and when none of the image signals in a block should be recorded, the supply of the selection signal to the recording element blocks in the selection order is prohibited, thereby reducing the power consumption. Another object of the present invention is to provide an image signal recording method that reduces the amount of heat generated.

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

In this embodiment, in order to simplify the explanation, one line is assumed to be 20 bits, and the line is divided into four blocks of 5 bits each. However, the present invention is not limited to this.
In FIG. 2, 1 and 2 are serial-in/parallel-out shift registers that alternately take in image signals every 5 bits; 3 is a counter that counts a clock CP synchronized with the image signal and outputs an output every 5 bits; 4 is a shift register switching flip-flop which is driven by the output of counter 3 and inverts the output; 5 and 6 receive the Q and Q outputs of flip-flop 4, respectively, and are switched on and off with a 5-bit shift based on the clock CP. Gates 7, - 75 (72, 73, 74 are omitted in the drawing) and 8, - 85 (82, 83, 84 are omitted in the drawing) supply shift clocks CP3 and CP2 to shift registers 1 and 2. These are gates that send out 5-bit image signals in parallel from shift registers 1 and 2, respectively, and open and close alternately in response to the Q and Q outputs of flip-flop 4 and in the opposite relationship to gates 5 and 6. . Due to the operation of these parts, gates 9, to 95 (92, 93,
94 is omitted in the drawing), the serial 5 of the image signal is
Each time it takes to transfer a bit, 5-bit image signals are sent out in parallel, and each is applied to the base of a transistor TR as shown in FIG. In this embodiment, the "black" of the image signal is binary-valued and the "H" (or "
1”), and “white” corresponds to the binary level “L” (or “0”). 10 is a mono-multi for printing time width control driven by the output of the counter 3; 11...
114 is the output (print pulse) A of Monomatil 10 by 4
12 is a 4-bit counter that cyclically counts the output of counter 3, and 13 decodes the output of counter 12 and outputs it. B~
This is a decoder that opens the gates 11, to 114 in a fixed order with & for only the time required to transfer 5 serial bits of the image signal.

According to each of these parts, the transistor TR2 in FIG.
, TR2, . . . become conductive for a period of the pulse width of the printing pulse A in a fixed order. By the way, the gate 14 for inhibiting the transmission of selection signals, which is interposed between the monomulti 10 and the gates 11, to 114, is used to prevent even one bit of the image signal "H" from being recorded in the image signal of the block whose selection order has arrived. If not, transfer of print pulse A is prohibited and gate 11.
A block selection signal is not sent from any of the blocks 114 to 114.

That is, flip-flops 15 and 16 monitor whether or not there is a black signal "H" in the 5-bit image signals transferred to shift registers 1 and 2, respectively. The flip-flops 15 and 16 operate when there is no black signal "H" for even 1 bit in the image signal every 5 bits.
During the selection period of the block in which the 5 bits are to be recorded, a signal is sent via gates 17 and 18 or gates 19 and 18 to close gate 14. To enable the above-mentioned operation, flip-flop 4 is connected to flip-flop 15.
The image signal is guided 5 bits at a time through a gate 20 which is gate-controlled by the Q output of the flip-flop 4, and the image signal is transmitted 5 bits at a time through a gate 21 which is gate-controlled by the Q output of the flip-flop 4. guiding and being The output of the clearing monomulti 22 driven by the output of the monomulti 10 is sent to the flip-flop 15 via the gate 23 gate-controlled by the Q output of the flip-flop 4 on the one hand, and the Q output of the flip-flop 4 on the other hand. It leads to the flip-flop 16 through a gate 24 which is gated at . Further, gate 17 is gated by the Q output of flip-flop 4, and gate 18 is gated by the Q output of flip-flop 4. With the above basic structure, the gate 14 is always open while the flip-flops 15 and 16 are detecting at least 1-bit black signal "H" in each 5-bit image signal that is alternately led. Therefore, block selection signals are cyclically sent out from the gates 1 1 to 1 14 in a fixed order, and the recording means operates normally.

However, the 5 led by the flip-flop 15 (16)
If there is no black signal “H” for even one bit in the bit image signal, the output side gates 7, to 75 (8, 8,
Since the gate 14 closes during the period when ~85) is open,
One of the outputs B, ~B4 of the decoder 13 during the same period, and the gates 11, ~11 corresponding to the block whose selection order has arrived.
Even if one of the four gates is selected, no block selection signal is sent out from the selected gate.

As a result, in the recording method shown in FIG. 1, the transistor TR2 common to the block is connected to each recording electrode, day, day, . . .
During the period when the black signal "H" is not supplied to any of the transistors TR, , TR, . . . corresponding to the transistors TR, TR, . It is reduced in proportion to the white signal content. Note that the recording method of the present invention is not limited to electrostatic recording, but can also be applied to other recording methods (for example, thermal recording) in which recording is performed in units of blocks.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a main part showing an example of a recording means in electrostatic recording, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a signal waveform diagram of each part of FIG. 2. 1, 2...Shift register, 3, 12...Power counter, 4
, 15, 16... flip-flop, 10, 22... monomathyl, 13... decoder. 1 figure, 2 figures, 3 boxes

Claims (1)

[Claims] 1 Divide into a large number of blocks of recording elements, select these multiple blocks in a predetermined order by supplying a selection signal to the selection drive circuit of each block to drive them, and select the recording elements in these selected blocks. In an image signal recording method that performs image recording by simultaneously driving in accordance with an image signal, it is determined whether there is an image signal that should drive a recording element among the image signals corresponding to all recording elements in a block whose selection order has arrived. and a gate circuit that prohibits the supply of selection signals to the selection drive circuit of the corresponding block and puts the selection drive circuit into a non-drive state when the discrimination circuit determines that there is no image signal. An image signal recording method characterized by comprising: