JPS6151824B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image recording device that records an image according to a received image signal.

A facsimile machine optically reads and transmits the original to be transmitted (hereinafter referred to as the transmitted original) on the sending side for each scan, and when one scan is completed, the transmitted original is moved by one scanning line and transferred onto the next scanning line. The image signal is read and transmitted. This procedure is then repeated to complete sending one sheet of the original.

On the other hand, the receiving side receives the image signal sent from the transmitting side as described above, reproduces it, records it, and prints it out. Generally, facsimile uses band compression technology, so the feed speed of each scanning line varies depending on the compression ratio. Therefore, the feeding speed of the image signal becomes non-uniform, and the feeding speed of the transmitted original and recording paper also becomes non-uniform. Conventionally, stepping motors have been used to feed these recording sheets. The stepping motor is suitable as a power source for a mechanism such as a facsimile machine that prints out paper by feeding it at a non-uniform speed for each scanning line. Therefore, it is often used in machines that require control to maintain paper feeding accuracy and ensure paper feeding for one scan. However, since the stepping motor rapidly and intermittently performs paper feeding, etc. for each scan, it generates noise and consumes a large amount of power. Figure 1a shows the relationship between the print command pulse and paper feed speed when a stepping motor is used for paper feeding, and Figure 1b shows the relationship between the input pulse of the stepping motor and the amount of movement. be. In FIG. 1b, when an input pulse is applied to the stepper motor drive circuit, the stepper motor rapidly rotates through one step angle.
At this time, overshoot or vibration occurs because the pulse motor, drive device, roll paper (wrapped recording paper), etc. have inertia. This vibration is transmitted to the recording paper, the main body of the facsimile machine, etc., and generates large noise.

Generally, this noise is a serious drawback for fax machines used in offices. For this reason,
The conventional stepping motor drive circuit is equipped with a braking resistor, but its effectiveness is extremely poor.
Furthermore, as a result of providing the braking resistor, it is necessary to use a larger shape than when no braking is performed in order to obtain a constant torque. Therefore, it has not been possible to reduce the size of the receiver body.

On the other hand, if paper could be fed continuously and smoothly, it would be possible to reduce noise, etc.
In facsimile machines that use bandwidth compression technology, the transmission speed is non-uniform. Therefore, in order to send the recording paper continuously, it is sufficient to memorize all the information for one screen and then send the recording paper at a constant speed, but since there is a large amount of recorded information for one screen, a large capacity memory is required. It becomes necessary.

The present invention provides an image recorder that is provided with a memory (storage means) having a relatively small capacity, that allows the storage amount of received image signals in the storage means to be accurately grasped, and that can be written and read line by line. The purpose is to provide equipment.

Embodiments of the present invention will be described below with reference to the drawings. The various signals shown in FIG. 2 constitute a signal transmitted by a transmitter (not shown), and include a start signal 3a, an image signal 3b, and a synchronization signal 3c.

This transmission signal is input to the modem 2 via the telephone line 1 shown in FIG. The signal demodulated by modem 2 is input to decoder 3, and start signal 3
a, image signal 3b, synchronization signal 3c, clock 3d
Classify and extract. Each image signal (3
b, 3b'...etc.) are each composed of image information for one line, and each line's image signal (3b, 3b'..., etc.) is composed of image information for one line.
b'...etc.) between synchronization signals (3c, 3c'...etc.)
is inserted. The image signal represents the black and white of each pixel obtained by scanning as a binary signal of 1 and 0. The clock 3d is extracted by the modem 2 itself from the transmitted signal. The start signal is inserted by the transmitter at the beginning of the transmission signal to instruct the start of transmission.

In FIG. 3, first, the start signal 3a is N
Advance ring counters 4, 5, read counter 6,
The write counter 7 is set to 0 to prepare for reception.
Next, when the image signal 3b is input to the multiplexer 9, since the first output of the N-ary ring counter 4 is 0, the address "0" of the multiplexers 9 and 10 is specified. Since the multiplexers 9 and 10 are assigned the "0" address, the input data signal is input to the buffer register 8-φ in synchronization with the write clock. 1024 to 2048
Consists of pixels. ) consists of a shift register that can store memory. Then, an arbitrary number of N lines of buffer registers are provided]. Image signal 3b
is thus stored in the buffer register 8-φ. When one line of image signals is input to the buffer register, a synchronizing signal 3c (line end signal) is input, and the N-ary ring counter 4 and write counter 7 are incremented by one. Therefore, multiplexers 9 and 10 point to address 1,
The next image signal 3b' is input to the buffer register 8-1 in the same manner as described above. When the image signal 3b' has been transmitted, a synchronizing signal 3c' is input and the N-ary ring counter 4 and write counter 7 are incremented. In this way, the image signal for each line is sequentially recorded from buffer register 8-φ to buffer register 8-N-1.

Further, the write counter 7 is input to one side of the subtracter 11 and the read counter 6 is input to the other side, and the value Y obtained by subtracting the number R of the read counters 6 from the number W of the write counter 7 is sent to the D/A converter 12. Output. The value Y is buffer register group 8
Indicates the number of unrecorded memory lines in the file.

The D/A converter 12 generates a voltage proportional to the value Y, and rotates the servo motor (moving means) 13. The rotation of the servo motor 13 causes the roller 1 to
4, 14' rotate, and a tachometer 15 connected to the roller 14' generates a print pulse (line recording reference signal) proportional to the rotational speed of the roller 14'. The print pulse increments the read N-ary ring counter 5 and the read counter 6 and triggers the read clock generator 16. When the readout clock generator 16 is triggered, it generates a readout clock and outputs, for example, an image signal (for example, 1024 bits or 2048 bits) of the buffer register 8-φ (one line).

On the other hand, the output of the N-ary ring counter 5 is input to the multiplexer 21 and the data selector 22. The multiplexer 21 distributes the read clock to the buffer register to be read out of the buffer register group 8 (storage means). That is,
The N-ary ring counter 5 is incremented by the print pulse, and the buffer register 8 is incremented in order from address 0 to address N every time a print pulse is generated.
- Outputs image signals from φ to 8-N-1.

In this way, the image signal stored in the buffer register group 8 is written to the serial-parallel conversion register 18 via the data selector 22. Further, the print command pulse output from the delay circuit 17 causes the image signal written in the serial-parallel conversion register 18 to be printed out from the recording head 19 (recording means) onto the recording paper 20.

The image signal and synchronization signal are 3b and 3b, as shown in Figure 2.
3c3b', 3c'... are input alternately, so the count value of the write counter 7 depends on the synchronization signals 3c, 3c'...
It increases as 1, 2, 3, etc. according to the input of c'... This output is subtracted by subtracter 11, and the D/A
The rotation speed of the servo motor 13, that is, the feeding speed of the recording paper 20 is increased through the converter 12. This situation is shown by line segment 23 in FIG. 4a. When the tachometer 15 rotates due to the rotation of the servo motor 13, the print pulse is input to the reading counter 6, so the output Y (=WR) of the subtracter 11 becomes approximately constant. Therefore, the rotational speed of the servo motor 13, that is, the feeding speed of the recording paper 20 is also constant. This situation is shown by line segment 24 in FIG. 4a.

When the reception is completed, the transmission of the image signal 3b and the synchronization signal 3c is stopped, only the read counter 6 counts up, and the calculated value of the write counter 7 remains unchanged. Therefore, the output value Y of the subtracter 11 is...
3, 2, 1, 0, and accordingly, the rotational speed of the servo motor 13, that is, the feeding speed of the recording paper 20 also decreases. This situation is shown by line segment 25 in FIG. 4a. On the other hand, recording is performed at a speed proportional to the rotational speed of the servo motor 13 in accordance with print pulses generated from the output of the tachometer 15. This situation is shown in FIG. 4b. In the initial state, as described above, the speed of the servo motor 13 is low and the feeding speed of the recording paper 20 is low. Therefore, the print command pulse is generated less frequently, and the image signal 3b is sent to the buffer register group 8, and the synchronization signal 3b is sent to the buffer register group 8.
c are respectively accumulated in the write counter 7.
As a result, as the output of the write counter 7 increases, the feeding speed of the recording paper 20 increases, and accordingly, the frequency of print command generation pulses also increases. In this way, recording on the recording paper 20 is performed at a speed proportional to the difference between the write counter 7 and the read counter 6. That is, recording is performed at a speed proportional to the amount of image signals stored in the buffer register group 8. After receiving the image signal, it is recorded until the output of the subtracter 11 becomes 0, and the fourth
As shown by line segment 25 in Figure A, the paper feeding speed gradually slows down, and when it finally reaches 0, electronic transmission of one sheet of original is completed.

As described above, the present invention grasps the amount of unrecorded image signals in the storage means (buffer register group 8) on a line-by-line basis from the line end signal (synchronization signal 3C) and the recording reference signal (print pulse), and Depending on the number of recording lines, the moving means (servo motor 1
3), it is possible to record line by line without requiring a large-capacity storage means and without overflowing the storage means. Furthermore, each line can be recorded at the same speed, and the configuration and control of the recording means can be greatly simplified.

[Brief explanation of the drawing]

Figure 1a is a diagram showing the relationship between print command pulses and paper feed speed, Figure 1b is a diagram showing the relationship between input pulses and the amount of movement of the pulse motor,
Fig. 2 is a diagram showing the configuration of the electronic transmission signal, Fig. 3 is a diagram of the main mechanism and electrical circuit of the image recording apparatus of this embodiment, Fig. 4a is a diagram showing the feeding speed of the recording paper, and Fig. 4b is a diagram showing the feeding speed of the recording paper. FIG. 4 is a diagram of print command pulses corresponding to FIG. 4a; In the figure, 2... modem, 3... decoder, 4, 5... N-ary ring counter, 6... read counter, 7...
...Write counter, 8...Buffer register group (storage means), 9, 10, 21...Multiplexer, 11...Subtractor, 12...D/A converter, 13...Servo motor (transfer means), 15 …
...Tachometer, 16...Readout clock generator, 1
7...delay circuit, 18...serial-parallel conversion register, 19...recording head (recording means), 22...data selector.

Claims (1)

[Claims] 1. A decoding means for decoding the received coded image signal, an accumulating means for temporarily accumulating the decoded image signal, and a line for generating a line end signal indicating that the accumulating means has finished accumulating one line's worth of image signals. a signal generating means; a reading means for reading out the image signal stored in the storage means line by line; a recording means for recording the image signal read from the reading means on a recording medium line by line; A moving means for relatively moving the medium in a direction substantially perpendicular to the line direction; generating a line recording reference signal serving as a reference for a reading operation for one line by the reading means; and a recording operation for one line for the recording means. controlling the movement of the moving means in accordance with the number of lines of unrecorded image signals stored in the storage means obtained by the recording reference signal generating means, the line end signal and the recording reference signal; An image recording apparatus for recording an image according to a received image signal, characterized in that the apparatus comprises a control means for stopping the movement when there is no unrecorded image signal for one line in the storage means.