JPH0470160A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To execute optimum printing respectively of received pictures having various sub scanning line density by generating a transfer end signal when a printing data for the prescribed number of lines is outputted, and controlling the printing density of a printing head based on the sub scanning line density of the received picture according to the transfer end signal. CONSTITUTION:When the printing data for the prescribed number of lines is outputted from a picture data transfer control means 40, a transfer end signal generating means 40a-1 outputs the transfer end signal. A printing density control means 40b receives the transfer end signal and outputs an output signal in an active state based on the sub scanning line density of the received picture. A printing head 40d can control the printing density according to the length of time for electrification by electrifying bits corresponding to the black picture elements of the printing data in a storing means 40c only for time when the output signal of the printing density control means 40b is activated. Thus, optimum printing can be executed even of the received pictures of various sub scanning line density.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a facsimile apparatus that is capable of optimally printing even received images having different sub-scanning line densities.

(Prior Art) Conventionally, as a technology in this kind of field, there has been a technology as shown in FIG. 2, for example. The configuration will be explained below using figures.

FIG. 2 is an overall configuration block diagram showing an example of the configuration of a conventional facsimile machine.

This facsimile apparatus includes a modem 1 that modulates transmission image data S1 to send out a transmission signal D1, and demodulates transmission signal D2 to extract reception image data S2.

An image processing section 2 is connected to the modem 1, and further connected to the image processing section 2 are a reading section 3 for reading an input document and a recording section 4 for recording the received image on recording paper. Here, the image processing unit 2 performs one-dimensional or two-dimensional data compression encoding to reduce the amount of output data from the transmission reading unit 1, and also performs decoding to expand the received image data S2. This is the circuit that does this.

On the other hand, a control section 5 commonly connected to the modem 1, image processing section 2, reading section 3, and recording section 4 is connected to an operation panel 6 such as a keyboard for performing input operations. Here, the control unit 5 is a circuit that is composed of a microprocessor or the like and controls the entire device such as the modem 1, the image processing unit 2, the reading unit 3, the recording unit 4, and the operation panel 6.
It is made up of etc.

This facsimile machine operates as follows.

For example, when the transmission signal D2 containing the received image data S2 is received by the modem 1, the transmission signal D2 is received by the modem 1.
2 and extracts received image data S2. Thereafter, the received image data S2 is decoded by the image processing section 2 and sent to the recording section 4, where it is printed on recording paper as a received image.

(Problem to be Solved by the Invention) However, in the facsimile machine having the above configuration, the print density remains set at the optimum value when the line density in the sub-scanning direction is 7.7 lines/mm (hereinafter referred to as fine mode). The pixel density in the main scanning direction is 8 dots/W, and the line density in the sub-scanning direction is 15.4 lines/! Ql! When printing a received image set in + (hereinafter referred to as super fine mode), the linear density is doubled in the sub-scanning direction, so compared to normal printing in fine mode shown in Figure 3 (a>), the printed dots are The overlapping area becomes larger and the print is blurred (Fig. 3 (b)).On the other hand, if the received image in fine mode is printed while the print density is set to the optimum value in super fine mode, As shown in Figure (a), the print becomes lighter and blurred compared to normal printing in super fine mode (Figure 4 (b)). Therefore, the print density is between fine mode and super fine mode. Therefore, the printing quality was not fully satisfactory in both fine mode and super fine mode.

The present invention provides a facsimile machine that solves the problem of the prior art, which is that the print quality is not sufficient.

Means for Solving the Problems> In order to solve the above problems, the present invention provides a decoding means for decoding received image data of a predetermined sub-scanning line density, and an output of the decoding means as print data. An image data transfer control means for outputting at a predetermined timing, a storage means for storing at least one line of the print data, and a print head for printing the print data in the storage means at a predetermined print density. The following measures are taken in the facsimile machine.

transfer end signal generation means for outputting a transfer end signal when a predetermined number of lines of print data are output from the image data transfer control means; A print density control means for controlling density is provided.

(Function) Since the facsimile apparatus of the present invention is configured as described above, the transfer end signal generating means outputs the transfer end signal when a predetermined number of lines of print data is output from the image data transfer control means. . The print density control means receives the transfer end signal and outputs an activated output signal based on the sub-scanning line density of the received image. The print head energizes the bit corresponding to the black pixel of the print data in the storage means only while the output signal of the print density control means is activated.

The print density can be controlled by changing the length of the current application time.

Therefore, the above problem can be solved.

(Embodiment) FIG. 1 is a block diagram of the main part of a facsimile machine showing an embodiment of the present invention, and elements common to the conventional elements shown in FIG. 2 are given the same reference numerals.

This facsimile device differs from the conventional one shown in FIG.
, the reading section 3, the control section 5, and the operation panel 6 have the same configuration.

This facsimile machine records received images using an electrophotographic method using a light emitting diode (hereinafter referred to as LED) in the print head, and has an image processing section 2 which encodes transmitted image data S1 (not shown). In addition to the encoding means, it has a decoding means 2a. The decoding means 2a is a circuit that decodes received image data S2, which is coded data of a received image, and outputs decoded data S3 of the number of bits corresponding to the number of pixels to the recording section 40 in accordance with the read clock C1.

The recording unit 40 includes an image data transfer control means 40a, a print density control means 401), and a shift register 40 which is a storage means.
c, and an LED print head 40d.

The image data transfer control means 40a is a circuit that takes in the decoded data S3 in synchronization with the read clock C1, transfers the decoded data S3 as print data S4, and outputs it to the shift register 40c in synchronization with the lock C2.

Furthermore, the image data transfer control means 40a includes a transfer end signal generating means 40a-1 that outputs a transfer end signal S5 to the print density control means 40b at the timing when one line of print data S4 has been transferred. .

The print density control means 40b controls the control clock output from the CPU based on the print density switching signal S6 corresponding to the sub-scanning line density (super fine mode or fine mode) of the received image when the transfer end signal S5 is input. This circuit outputs a strobe signal S7 to the print head 40d in accordance with C2. The register 40c is a circuit that transfers one line of print data S4 and stores it in synchronization with the lock C2. The print head 40d has a register 40c.
The output S8 has a function of energizing the bit corresponding to the black pixel only while the strobe signal S7 is on.

FIG. 5 is a block diagram of the internal configuration of the print density control means 40b in FIG. 1.

The count table 40b-1 is a ROM (read
This is a table that stores the count number in fine mode, and similarly,
A count number table 40b-2 configured with a ROM or the like is a table in which counts in the super fine mode are stored. These tables 40b-1, 40
b-2 is connected to the input side of selector 40b-3.

Further, a print density switching signal S6 for switching is connected to the selector 40b-3, and the input side of an up counter 40b-4 is connected to the output side of the selector 40b-3. Furthermore, on the input side of the up counter 40b-4,
A transfer end signal S5 and a control clock C5 for counting are connected, and a strobe signal S7 is connected to the output side.

FIG. 6 is an operation timing chart of FIG. 1, and with reference to this diagram, the operation in fine mode (A>) and the operation in super fine mode (B) will be explained.

(A>Operation in fine mode When fine mode received image data S2 is extracted from transmission signal D2 by the modem 1 shown in FIG. 2, the received image data S2 is input to the decoding means 2a.Decoding In the means 2a, the received image data S2 is decoded,
As decoded data s3 with the number of bits corresponding to the number of pixels,
Image data transfer control means 40 according to readout clock C1
output to a. The image data transfer control means 40a takes in the decoded data s3 in synchronization with the read clock C1, transfers the decoded data S3 as print data S4, and outputs it to the shift register 40c in synchronization with the lock C2 (see FIG. time Tl) Furthermore, when the print density switching signal s6 at InL" level is input to the selector 4°b-3 of the print density control means 40b (fine mode),
Table 40b-1 is selected, and the fine mode count stored in table 40b-1 is output from selector 40b-3 to up counter 40t)-4.

On the other hand, at the timing when one line of print data S4 is transferred to the register 40c, the transfer end signal generating means 40a
-1, the transfer end signal S5 is output to the counter 40b-4 of the print density control means 40b (time T2 in FIG. 6).
. When the transfer end signal S5 is input to the counter 40b-4, the counter 40b-4 starts counting the control clock C5 and turns on the strobe signal S7 (time T3 in FIG. 6). Thereafter, after counting the specified number of counts for fine mode, the strobe signal S7 is turned off (time T4 in FIG. 6).

This strobe signal S7 is input to the print head 40d. The print head 40d outputs the output S8 of the register 40c.
The bit corresponding to the black pixel is sent to the strobe signal S7.
Power is applied only when is on.

(B) Operation in super fine mode When received image data S2 in super fine mode is decoded by the decoding means 2a and outputted as decoded data S3 to the image data transfer control means 40a, the image data transfer control means 40a is The data transfer control means 4○a transfers the print data S4 and locks C.
2, the signal is output to the shift register 40c (time T11 in FIG. 6).

On the other hand, when the "H" level print density switching signal S6 is input to the selector 40b-3 of the print density control means 40b (super fine mode), the table 40b-2 is selected and the data is stored in the table 40b-2. The count number for the super fine mode that has been set is output from the selector 40b-3 to the counter 40b-4. Further, at the timing when one line of print data S4 is transferred to the register 40c, a transfer end signal S5 is outputted from the transfer end signal generating means 40a-1 to the counter 40b-4 (time T12 in FIG. 6). The transfer end signal S5 is sent to the counter 40b-4.
When the counter 40b-4 receives the control clock C
5 and turns on the strobe signal S7 (time T13 in FIG. 6). After that, after counting the specified number of counts for the super fine mode, the strobe signal S7 is turned off (time T14 in FIG.
).

When this strobe signal S7 is input to the print head 40dG, the print head 40d energizes the bit whose output S8 corresponds to a black pixel only while the strobe signal S7 is on. The longer this energization time is, the darker the printing becomes.

As described above, in this embodiment, since the printed dot area shown in FIGS. 3 and 4 becomes larger, the energization time is increased in the fine mode, and the energization time is increased in the super fine mode.
The ON time of the strobe signal S7 is controlled so that the current application time is shortened and the respective optimum printing densities (Fig. 3 (a) and Fig. 4 (a)) are achieved.This allows for good printed products. You can get a parable.

Note that the present invention is not limited to the illustrated embodiment, and various modifications are possible. For example, there are the following variations.

(I> In the above embodiment, LE is used as the recording method of the received image.
Although an electrophotographic method using a D head is used, the method is not limited thereto, and, for example, a thermal method in which color is developed by the heat of a heated bed, a thermal transfer method, or the like may be used.

(II> Although the image data transfer control means 40a and the print density control means 40b of the above embodiment were configured within the recording section 40,
For example, it may be configured within the control section 5 shown in FIG.

(III> Transfer end signal generation means 40a1 of the above embodiment
is provided within the image data transfer control means 40a, but is not limited thereto, and may be provided outside the image data transfer control means 40a.

(IV) In the above embodiment, the count number table 40
b-1 and 40b-2 were configured individually with ROM etc.
For example, it may be configured in one ROM. This allows the amount of hardware to be reduced.

(V) Although the register 40C is used as the storage means in the above embodiment, it is not limited thereto as long as it meets the spirit of the present invention.

(VI) Counter 40b- in print density control means 40b
4, an up counter is used, but even if it is replaced with a down counter, for example, the same effect as in the above embodiment can be expected.

(VI> The transfer end signal generating means 40a-1 is configured to output the transfer end signal S5 at the timing when the print data for the go line is transferred, but it is not limited to the print data for one line; The configuration may be such that the transfer end signal S5 is output when more than one line of print data has been transferred.Similarly, the register 40c is configured to store one line of print data S4; It may be capacity.

(Effects of the Invention) As described above in detail, according to the present invention, when a predetermined number of lines of print data is output, a transfer end signal is generated, and the transfer end signal causes the sub-scanning line of the received image to be Since the print density of the print head is controlled based on the density, optimal printing can be performed for received images having different sub-scanning line densities, and the quality of the print images is improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the main part of a facsimile machine showing an embodiment of the present invention, Fig. 2 is a block diagram of the entire structure of a conventional facsimile machine, and Figs. 1 (a > (b) is a diagram showing another conventional print image, FIG. 5 is an internal configuration block diagram of the print density control means in FIG. 1, and FIG. 6 is a diagram similar to that in FIG. 1. 2a...decoding means, 40a...image data transfer control means, 40a-, =...transfer path r signal generation means, 40b... ...Print density control means, 4
0C...Music shift ν register, 40d...Print head, s2...Received image data, S4...
Print data, s5...Song transfer end signal. Fine mode printing (a no suit (0 - fine mode ゛ 0 character (b) Seira's printing stroke Figure 3 suit (° - fine mode 10 characters (a no fine mode printing (b) Restoration printing stroke 4th style sword

Claims (1)

[Scope of Claims] A decoding means for decoding received image data having a predetermined sub-scanning line density; an image data transfer control means for outputting the output of the decoding means as print data at a predetermined timing;
A facsimile apparatus comprising a storage means for storing the print data for lines, and a print head for printing the print data in the storage means at a predetermined print density, wherein a predetermined number of lines is set by the image data transfer control means. a transfer end signal generation means for outputting a transfer end signal when the print data of is output; and a print density control means for controlling the print density based on the sub-scanning line density when the transfer end signal is input. A facsimile machine characterized by: