JP3080334B2 - Facsimile machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile apparatus having a function of adjusting a reading density read by a document reading means.

[0002]

2. Description of the Related Art Conventionally, this type of facsimile apparatus has a charge coupled device (CCD) for converting an image of a document into image data.
Device) a document reading means such as a unit or a contact image sensor, an analog circuit for converting this image data, an image processing LSI, and the like. The image processing LSI can set a slice level for white / black determination in an internal register, and the setting of the slice level can be easily changed by software. In a circuit configuration that does not use an image processing LSI, the setting of the slice level for white / black determination is changed by an analog circuit.

By changing the setting of the slice level for the white / black determination, it is possible to adjust the density of the read density in, for example, binary reading.

Further, a facsimile apparatus having a function of reading a halftone image has a dither matrix circuit formed inside an image processing LSI or a dedicated circuit, so that image data read by an image sensor is read. Are converted by the dither matrix circuit in comparison with the dither pattern. The read density of such a halftone image can be adjusted by adjusting a dither pattern and performing analog correction.

[0005] In both the binary reading and the halftone reading as described above, the change of the slice level setting of the white / black determination for adjusting the reading density of the document is performed in accordance with the density of the transmission document. Other than being set automatically, the setting is fixed or manually adjusted by the keyboard.If it is set when copying or facsimile communication of a document is started, it is fixed until reading of this document is completed. It has become so.

[0006]

At present, with the spread of plain paper facsimile machines, facsimile machines having a so-called laser printer as recording means are increasing.

However, in this laser printer, since the dots constituting an image are basically large, the recording density tends to be higher as a whole as compared with, for example, a printer using a thermal head. Therefore, when the facsimile machine of the other party performing transmission from the above-mentioned conventional facsimile apparatus uses a laser printer, even if the adjustment of the reading density on the transmission side is set to be thin, black is generated by the laser printer of the other party. Although it is easy to obtain a good appearance, it is easy to obtain good recording, but if the reading density adjustment on the sending side is set to be high,
On the other hand, there is a problem that the recording on the other side tends to be blackish overall, and particularly, the halftone tends to be rendered dark overall.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a facsimile apparatus which can obtain good recording in appearance in accordance with recording means provided in a facsimile apparatus on the other side. .

[0009]

Facsimile apparatus of the present invention, in order to solve the problems] includes a document reading means for reading the transmission original, recording means provided in the mating receiver in a communication procedure to determine the time of transmission, the determination was counterpart received The recording means of the machine is an electrophotographic
If it is a linter, the slice level of the white / black judgment
Change the settings to adjust the scanning density of the
Set the adjustment to be thin and use the halftone reading dither pattern.
Read density adjusting means for automatically adjusting the read density of the transmitted document by setting the scan matrix to a lighter pattern .

[0010]

[Action] In the facsimile apparatus of the present invention utilizes a communication procedure (protocol) when transmission, to determine a recording unit provided in the counterpart receiver in this, recording means for this determination was the mating receiver is provided is If you are an electrophotographic printer
Change the slice level setting for white / black judgment.
Adjustment of the reading density of the transmitted document lighter than normal.
Set the dither pattern matrix for halftone reading.
By setting the mix to a lighter pattern,
The record becomes black overall, especially the halftone is dark overall
Issues that tend to be automatically resolved,
It is possible to suppress toner consumption. In addition, white / black judgment
Slice level setting and halftone reading dither
All turn matrix settings are processed by software
Configuration is simple because it is possible only by adding
Is reduced.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a facsimile apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an embodiment of a document reading means and a reading density adjusting means which are image reading systems of the facsimile apparatus of the present invention. The output terminal of the differential amplifier 12 is connected to the input terminal of an AGC (automatic gain adjustment) amplifier 13, and further connected to the input terminal of the differential amplifier 12.
An output terminal of the AGC amplifier 13 is connected to an input terminal of an image processing LSI 14 as reading density adjusting means. The image processing LSI 14 is connected to the CPU bus 15, and the output terminal of the image processing LSI 14 is connected to a serial (S) / parallel (P) conversion circuit 16. Reference numeral 16 is connected to an image bus 18 via a latch circuit 17.

The CPU bus 15 is connected to a CP (not shown).
U, and the image bus 18 is connected to a telephone line through a not-shown compression / decompression process and a modem.

When the transmission original is read by the original reading means 11, image data is output from the original reading means 11, and the image data is output to the differential amplifier 12 and the AGC amplifier.
The data is input to the image processing LSI 14 via the input terminal 13. The image processing LSI 14 is controlled by the CPU and can set a slice level for white / black judgment in an internal register. The setting of the slice level can be easily changed by software. ing.

The image data input to the image processing LSI 14 is converted from an analog signal to a digital signal in accordance with the slice level of white / black judgment of an internal register and output as a binary digital signal. The signal is input to the serial / parallel conversion circuit 16. Then, the image data converted into the binary digital signal is output to the image bus 18 via the latch circuit 17, and is further output to the telephone line at a communication speed set through a compression / expansion process and a modem. I have.

When reading a half tone, the image data is converted by comparing it with a dither pattern using a dither pattern matrix for half tone reading provided in the image processing LSI 14.

Next, the operation of the facsimile apparatus of the above embodiment when transmitting a document will be described with reference to the flowchart of FIG. 1 and the explanatory diagram of the communication procedure of FIG.

[0018] First, the facsimile apparatus on the transmitting side, that sends the call sound (CALL) through a telephone line (step 1).

When the receiving facsimile apparatus as the other party's receiver in the reception standby state receives this ringing tone, the receiving facsimile apparatus follows the protocol (communication protocol), and the non-standard function (NSF, in-house mode) function),
Called terminal identification (CSI), digital identification signal (DIS)
Respond the reference format of At this time, if the recording means of the facsimile apparatus on the receiving side is a so-called laser printer which performs transfer based on, for example, a latent image in electrophotography using laser light, the non-standard function (NS
By utilizing the function bit of F), it is indicated that the self-recording means is a laser printer.

When the facsimile machine on the transmitting side receives the non-standard function (NSF) reference format (step 2), it determines whether or not the non-standard function is set (step 3), and the non-standard function is set. If so, it is determined whether or not the recording means of the receiving facsimile machine is, for example, a laser printer using plain paper (step 4).

If the recording means of the facsimile apparatus on the receiving side is, for example, a laser printer, the setting of the slice level for white / black determination such as a register inside the image processing LSI 14 is changed by software to change the transmission original. The read density adjustment is set to be light, and the dither pattern matrix for halftone reading is rewritten to a light (bright) pattern (step 5).

Then, in a state where the transmitting facsimile apparatus transmits a training check (TCF) and the receiving facsimile apparatus responds with the reception preparation confirmation (CFR), the transmitting facsimile apparatus starts reading the transmission original. Then, the image data (PIX) is transmitted.

If the non-standard function is not set (step 3), or if the non-standard function is set, the recording means of the facsimile apparatus on the receiving side is not a laser printer but a thermal head for coloring thermal paper, for example. If it is determined that the printer is a so-called thermal printer (step 4), the reading density of the transmission original is set to normal, that is, the current level, and the transmission original is read and transmitted.

According to the facsimile apparatus of the present embodiment, at the time of transmission, it is determined in the communication procedure whether the recording means of the other facsimile apparatus is a laser printer or a thermal printer. By automatically adjusting the reading density of the transmission original according to the recording means of the other party's facsimile apparatus, and reading and transmitting the transmission original at the optimum reading density, the type of recording means of the other party's facsimile apparatus can be adjusted. Regardless, the quality of the recorded image can be improved by uniformly expressing the recording density of the other party. In particular, even when the facsimile apparatus of the other party uses a laser printer, it is possible to improve the problem that the recording density becomes high and the iris becomes black.

Since the setting of the reading density is automatically performed during the communication procedure, no manual operation is required and the operation of the facsimile apparatus is not complicated.

Further, the slice level for white / black determination is set.
Constant and halftone reading dither pattern matrix
By combining settings, you can easily improve the recording quality.
As well as the slice level for these white / black judgments
Setting and halftone reading dither pattern matrix
Since the reading density can be set only by adding software processing, the configuration can be simplified and the cost does not increase.

Then, the facsimile machine on the other end receives the thinly set image data.
The consumption of toner of the laser printer can also be suppressed.

FIG. 4 is a block diagram showing a configuration of a reading system of a facsimile apparatus according to another embodiment of the present invention, in which a circuit is formed without using the image processing LSI 14.

In this configuration, the output terminal of the original reading means 19 comprising an image sensor is connected to the input terminal of the differential amplifier 20, and the output terminal of the differential amplifier 20 is connected to the AGC amplifier 21.
Further, the output terminal of the AGC amplifier 21 is connected to an image processing analog circuit constituting reading density adjusting means. In this image processing analog circuit, the output terminal of the AGC amplifier 21 is connected to one input terminal of the comparator 22 and the input terminal of the analog / digital converter 23. A voltage setting resistor 24 and an analog switch 25 are connected to the other input terminal of the comparator 22, and an output terminal of the comparator 22 is connected to one input terminal of the multiplexer 26. Then, the output terminal of the analog / digital converter 23 is connected to the input terminal of the dither matrix comparison circuit 27, and the dither matrix comparison circuit 27
The output terminal of the dither matrix comparison circuit 27 is connected to the other input terminal of the multiplexer 26. And the multiplexer 26
Is connected to an input terminal of a serial / parallel conversion circuit 31, and this serial / parallel conversion circuit 31 is connected to a CPU bus line 33 via a latch circuit 32. This bus line 33 may be an image bus, and is connected to the analog switch 25.

When the transmission original is read by the original reading means 19, the image data is output from the original reading means 19, and this image data is sent to the image processing analog circuit via the differential amplifier 20 and the AGC amplifier 21. Is entered.

In this image processing analog circuit, the analog switch 25 is controlled by a CPU or the like to set a slice level for white / black determination, and the image data output from the AGC amplifier 21 and the analog switch 25 are controlled. The output is compared with a comparator 22 to convert the image data from an analog signal to a digital signal to obtain a binary signal.

The halftone image data is analog / digital.
The digital signal is converted from an analog signal to a digital signal by the digital converter 23, and further, a dither matrix comparison circuit
The signal 27 is compared with the dither pattern stored in the ROM 28 with a built-in dither pattern and converted into a binary signal.

Then, the binary signal from the comparator 22 and the binary signal from the dither matrix comparison circuit 27 are selectively input to the serial / parallel conversion circuit 31 by the multiplexer 26. The binary image data is output to a bus line 33 via a latch circuit 32, and is output to a telephone line through a compression / decompression process and a modem.

In this configuration, if it is determined in the communication procedure that the recording means of the facsimile apparatus on the receiving side is a laser printer, the analog switch 25 is set to C.
The slice level of the white / black determination (binary reading) is set to a low level by controlling with a PU or the like, and a thin (brighter) pattern is read out from the ROM 28 with a built-in dither pattern and compared in the reading of the halftone. Set as follows .

[0035]

According to the facsimile apparatus of the present invention, at the time of transmission, the recording means of the other receiver is determined in the communication procedure, and the determined recording means of the other receiver is used as the electronic means.
If the printer is a photographic printer, the white / black
Change the setting of the chair level and send the original from the normal state.
Adjust the reading density of the image lightly, and read the halftone
Dither pattern matrix set to a thinner pattern
By doing so, the other party's record becomes black overall, especially
Automatically solves the problem that halftones tend to appear dark overall
To be improved, it is possible to improve the quality of the recording by the recording means of the counterpart receiver, suppress the consumption of the toner
Can be controlled. In addition, setting the slice level for white / black judgment
And dither pattern matrix settings for halftone reading
Recording quality can be easily improved by combining
As well as the slice level
Setting and halftone reading dither pattern matrix
Can be set only by adding software processing
Therefore, the configuration can be simplified, and an increase in cost can be reduced.
Further, since the reading density is automatically set by software processing by the CPU, the operation of the facsimile apparatus does not become complicated.

[Brief description of the drawings]

FIG. 1 is a flowchart of software processing showing an embodiment of a facsimile apparatus of the present invention.

FIG. 2 is a block diagram showing a reading system of the facsimile apparatus.

FIG. 3 is an explanatory diagram of a communication procedure according to the embodiment.

FIG. 4 is a block diagram of a reading system showing another embodiment of the present invention.

[Explanation of symbols]

 11 Document reading means 14 Image processing LSI as reading density adjusting means

Claims (1)

(57) [Claims] And 1. A document reading means for reading the transmission original, recording means provided in the mating receiver in a communication procedure to determine the time of transmission, the recording means of this determination was counterpart receiver electronic
If the printer is a photographic printer, the white / black
Change the setting of the chair level and send the original from the normal state.
Adjust the reading density of the image lightly, and read the halftone
Dither pattern matrix set to a thinner pattern
And, a facsimile apparatus, characterized by comprising a reading density adjusting means for automatically adjusting the reading density of the transmission document.