JPS5843944B2 - two color facsimile machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a two-color facsimile device, and provides a two-color facsimile device capable of recording on both existing monochrome facsimile receivers and two-color facsimile receivers.

Two-color facsimile machines are extremely useful in cases such as modifying drawings and correcting minutes of meetings.

By the way, this two-color facsimile device also has one problem.

This means that two-color facsimile machines and existing monochrome facsimile machines cannot communicate with each other.

Particularly, when the sending side is a two-color facsimile machine and the receiving side is a monochrome facsimile machine, one color signal portion may not be recorded in the recorded image on the receiving side.

Therefore, when communicating between a two-color facsimile machine and a monochrome facsimile machine, a modulation circuit that is compatible with the demodulation circuit of the existing monochrome facsimile machine is required.

The present invention has been made to solve the above problems, and enables existing monochrome facsimile machines that use a synchronous detection circuit and an absolute value amplifier in the demodulation circuit to communicate without installing a new modulation/demodulation circuit. A two-color facsimile machine is provided.

An embodiment of the present invention will be described below with reference to the drawings.

Note that for convenience of explanation, two colors are determined in advance.

-The color shall be black and the others shall be red. FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a waveform diagram showing its operation.

In FIG. 1, 1 is a transmission document, 2 is a light source, 3 is a lens, and 4 is a half mirror having a filter function to reflect red light and transmit light of colors other than red.

5A and 5B are photoelectric converters, 6 is an addition circuit, and 7 is a subtraction circuit.

8A and 8B are amplifiers, 9 is an inverting circuit,
10 is an amplifier with a double amplification factor, 11 is an analog switch, and 12 is a resistor.

Reference numeral 13 denotes a ring modulator, which has a characteristic of modulating the carrier wave so that its phase differs by 1800 degrees when the input image signal is positive and when it is negative.

14 is a pulse generator that outputs a signal of a predetermined frequency to create a carrier wave.

The operation of this circuit will be explained below.

First, a transmission document 1 is scanned by a scanning light source of a light source 2,
The reflected light passes through the lens 3 and reaches the half mirror 4.

Of the reflected light that reaches the half mirror 4, the red light is reflected by the half mirror 4 and guided to the photoelectric converter 5B, where it is photoelectrically converted and an image signal showing red is obtained.

Further, of the reflected light that has reached the half mirror 4, the light excluding the red color passes through the half mirror 4 and is connected to the photoelectric converter 5A.
There, the image signal a is photoelectrically converted and an image signal a without the red signal is obtained.

The signals a and signal S are input to an addition circuit 6 and a subtraction circuit γ, respectively, and the output of the addition circuit 6 is an image signal C covering the entire visual sensitivity range, and the output of the subtraction circuit 7 is an image signal C for a red image. A signal d is obtained.

Next, the image signal C is amplified by the amplifier 8A and then divided into two parts, one of which is sent to the inverting circuit 9 and the other to the double amplifier 10.
The output signal is outputted to one selected terminal 15 of the analog switch 11 through , and the other signal is output as is to the other selected terminal 16 of the analog switch 11 .

Here, the image signal d is amplified by the amplifier 8B and then controls the analog switch 11.

That is, when the image signal d is I+ +19, the selection terminal 17 of the analog switch 11 selects the selected terminal 15,
The selected terminal 16 is selected when the image signal d is '0''.

Therefore, the selection terminal 17 has a signal with the red signal removed on the +1 +jj side, and a signal amplified twice after inverting the red signal on the eljj side, centering on the reference voltage level ``'O''. An irregular ternary analog image signal e is obtained.

This signal e is biased with a predetermined voltage to produce a signal f
and is input to the ring modulator 13.

Then, the ring modulator 13 uses this signal f to modulate a signal with a predetermined frequency output from the pulse generator 14. When the signal f is positive, the carrier wave is, for example, "0", and the signal f is When the carrier wave is negative, the phase is, for example, "π", which is 180° 1', and a transmission signal g is obtained and outputted from the terminal 18.

Next, FIG. 3 will be explained.

FIG. 3 is a block diagram of a receiving section of a facsimile machine in one embodiment of the present invention.

In FIG. 3, 20 is an AGC circuit, 21 is a ring demosimulator, 22 is a carrier recovery circuit, and 23 is a phase recovery circuit.

24 is a facsimile machine control circuit, 25 is a full-wave rectifier circuit, 26 is a slice circuit, 27 is an analog switch, 2
8 is a half-wave rectifier circuit, and 29 is an inverting circuit.

30 is a black recording device, 31 is a soil display device, and 32 is a red recording device.

The operation of FIG. 3 will be explained below using the waveform diagram of FIG. 4.

The signal input from the input terminal 19 is amplified to a constant level by the AGC circuit 20 and becomes a signal.

This signal is divided into three parts, one of which is sent to the ring demodulator 21, the other to the carrier regeneration circuit 22, and the last one to the phase regeneration circuit 23.

The ring demodulator 21 demodulates the signal 1 using the reproduced carrier signal outputted from the carrier regeneration circuit 22, and obtains the signal 1.

This signal i is again distributed to three directions, one is through the full wave rectifier 25 and the slice circuit 26, and the other is the analog switch 2.
7, the other one passes through the half-wave rectifier 28 and the inversion circuit 29, and the signal j that becomes the control signal for the analog switch 27 is obtained, and the last one passes through the control circuit 24.
is input.

The control circuit 24 stores the arrival timing of the phase signal obtained from the phase recovery circuit 23 during phase matching at the beginning of facsimile communication, and determines whether the carrier wave of the phase signal portion transmitted from the transmitting side is sent in phase b. Since we know in advance that the phase signal will arrive at the stored phase signal, we check whether the phase signal part of the signal i is positive or negative at the arrival timing of the memorized phase signal, and control the phase of the regenerated carrier signal output from the carrier regeneration circuit. ing.

Therefore, in the output signal i of the ring demosimulator 21, the black signal (same as the signals other than red) always appears on the positive side, and the twice amplified red signal appears on the negative side.

The selection terminal 33 of the analog switch 2γ selects the selected terminal 35 when the control signal J of the analog switch 27 is positive, and conversely selects the selected terminal 35 when it is "0".
Select.

Therefore, the red reproduction signal m which is amplified twice is obtained at the selected terminal 35 of the analog switch 24, and the black reproduction signal l is obtained at the selected terminal 34 as well.

Then, the black reproduction signal l is input as is to the black recording device, and the red reproduction signal m, which has been amplified twice, is transmitted to the attenuator 3.
After being attenuated to a normal red reproduction signal n at step 1, it is input to the red recording device.

In this way, two-color facsimile communication becomes possible.

Next, FIGS. 5 and 6 will be explained regarding facsimile communication when the transmitting side is a two-color facsimile machine and the receiving side is an existing monochrome facsimile machine equipped with a synchronous detection circuit and an absolute value amplifier as a demodulation circuit. I will explain using

FIG. 5 shows a receiving section of an existing monochrome facsimile machine, and FIG. 6 is a waveform diagram for explaining FIG.

In FIG. 5, 41 is an AGC circuit, 42 is a synchronous detection circuit, 43 is an absolute value amplifier, 44 is a slice circuit, and 45 is a single color recording device.

The image signal input from the input terminal 40 is sent to the AGC circuit 41.
The signal is amplified to a certain level and becomes the signal p.

This signal p is input to the synchronous detection circuit 42 and becomes a signal q when it is synchronously detected.
3, the signal r is obtained.

If this signal r is inputted to the slice circuit 44, a monochrome reproduced signal S is obtained, and if this signal is inputted to the recording device 45, a monochrome reproduced recorded image is obtained.

That is, since the signal corresponding to red is amplified twice on the transmitting side, the portion of the output r of the absolute amplifier 43 corresponding to red can obtain a sufficiently high level.
Monochrome reproduced and recorded images can be obtained by passing through only one slice circuit.

In this example, the signal corresponding to red is amplified twice, but the magnification can be selected as appropriate by considering the relationship with the bias applied to the signal l in FIGS. 1 and 2. .

As described above, according to the present invention, by simply transmitting one two-color facsimile signal, it is possible to apply not only a two-color facsimile device but also an existing monochrome facsimile device equipped with a synchronous detection device and an absolute value amplifier in a demodulation circuit. Also, reproduced recorded images can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a transmitter of a two-color facsimile machine according to an embodiment of the present invention, FIG. 2 is a waveform diagram for explaining the operation in FIG. 1, and FIG. 3 is a two-color facsimile machine according to an embodiment of the present invention. A block diagram of the receiving section of the device, FIG.
FIG. 5 is a block diagram of a receiving section of an existing monochrome facsimile machine, and FIG. 6 is a waveform diagram for explaining the operation of FIG. 1... Original to be sent, 2... Light source, 3...
...Lens, 4...Half mirror-5A, 5
B...Photoelectric converter, 6...Addition circuit,
7... Subtraction circuit, 8A, 8B... Amplifier, 9... Inverting circuit, 10... Double amplifier, 11.27...・Analog switch, 13
...Ring modulator, 14...Pulse generator, 20...AGC circuit, 21
・・・・・・Ring demosulator, 22・・・・・・
Carrier regeneration circuit, 23... Phase regeneration circuit, 2
4... Control circuit, 25... Full wave rectifier circuit, 26... Slice circuit, 28...
Half-wave rectifier circuit, 29... Inversion circuit, 30...
...Black recording device, 31...Upper area display device, 32
... Red recording device, 41 ... AGC circuit, 42 ... Synchronous detection circuit, 43 ...
Absolute value amplifier, 44... Slice circuit, 45.
...Recording device.

Claims (1)

[Claims] 1 The signal obtained by scanning the transmission document is transmitted to the first
means for decomposing the color signal into a color signal and a second color signal having color components other than the first color signal, and means for synthesizing a signal obtained by inverting and amplifying the fourth color signal and the second color signal. , a means for converting the combined signal to a predetermined level according to the amplification factor of the first color signal, and a means for modulating the positive and negative parts of the signal after the level conversion with carrier waves shifted by 180 degrees from each other. A two-color facsimile machine comprising means for