JPH01126066A - Scanner - Google Patents

Abstract

PURPOSE:To obtain a picture with high quality by reading deviation information between forward and return scanning from a storage means and generating a moving timing signal from the deviation information so as to prevent the deviation of scanning with an inexpensive device. CONSTITUTION:The deviation between the forward and return scanning by the scanning means is stored in advance in a correction table 102 corresponding to a scale arranged along the moving path of the scanning means. The deviation information is read out of the correction table 102 according to the count obtained by a mark counter 101 corresponding to the scale. A step pulse generating circuit 103 generates a moving timing signal based on the deviation information and uses it as a prescribed timing signal to supply it to a moving means.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a scanning device applied to facsimile machines and the like.

BACKGROUND OF THE INVENTION FIG. 4 is a schematic perspective view showing a recording apparatus to which an example of a conventional scanning apparatus is applied.

This recording device has a pair of feed rollers 1 driven by a step motor capable of intermittent feed, which are arranged at a predetermined interval. transport.

Between the pair of feed rollers 1 is a guide shaft 3. Steady stop shaft 4
and the recording timing index that formed the scale (hereinafter referred to as
(referred to as indexes) 5 are arranged parallel to the direction indicated by the arrow, which is the main scanning direction. A first slit 6 indicating the start and end of recording and a second slit 7 indicating the recording timing for each bit are provided in the index 5 at positions corresponding to the recording position of the recording paper 2 by etching or the like. A carrier 8 is attached to the guide shaft 3 so as to be movable forward and backward.

The carrier 8 is driven by a step motor (not shown) and moves in the main scanning direction while being guided by the guide shaft 3 and the steadying shaft 4. Further, the carrier 8 has a recording head 9 which is a scanning element, and a first head which reads the scale of the index 5. Second detector 10
．． 11.

The first detector 10 detects the recording start and end timings, and the second detector 11 detects information corresponding to the recording timing for each bit.

In the recording apparatus configured as described above, recording of a predetermined width is performed by scanning the carrier 8 forward in the direction of the arrow with the recording paper 2 stationary, and when this recording is completed, recording is performed in the direction of the arrow a. Move the paper 2 by a predetermined width. Then, with the recording paper 2 stationary, the carrier 8 is scanned backward in the opposite direction to record a predetermined width, and when this recording is completed, the recording paper 2 is moved by a predetermined width in the direction of arrow a. Thereafter, the same operations as described above are repeated to obtain a predetermined image on the recording paper 2.

In addition, in the above-described image recording, for example, when recording m bit strings in the main scanning direction and n pit rows in the sub-scanning direction by one movement of the carrier 8 as shown in FIG.
1st. The position of the carrier 8 is confirmed based on the read value of the index 5 by the second detectors 10 and 11, and forward scanning is performed with reference to this confirmation result.

It controls the recording timing shift in backward scanning.

Problems to be Solved by the Invention By the way, when such a recording device is used in a facsimile machine, the recording pinch is, for example, 0.125 mm, and 1
The recording timing for each bit requires high density and high precision, but manufacturing the index 5 that can meet this requirement requires a lot of cost, resulting in an expensive device as a whole. was there.

Furthermore, if recording is performed on the recording paper 2 at fixed time intervals as the carrier 8 moves without providing slits corresponding to the recording pitch, deviations will occur in the main scanning direction during forward scanning and backward scanning as shown in FIG. As a result, image quality may deteriorate significantly. FIG. 7 shows the relationship between the recording deviation in forward scanning and backward scanning and the scanning position of the carrier 8 when no slit is provided.

In addition, in order to prevent the above-mentioned misalignment of the recording position between the forward scan and the backward scan without providing an expensive index, recording is performed only in the forward scan (or backward scan only), and in the backward (or forward) scan movement, It is conceivable to prevent recording. FIG. 8 shows the relationship between the printing deviation for each scan and the scanning position of the carrier when such printing is performed. Although the recording deviation can be reduced by performing such recording, there is a limit to how much time can be reduced for backward (or forward) scanning of the carrier, and there is a drawback that recording takes time.

The present invention has been made in view of the above-mentioned problems, and can be applied to a recording device or a reading device to prevent deviations in forward scanning and backward scanning without using expensive indicators, and to produce high-quality images. The object is to provide a scanning device that can be obtained without requiring much time.

Means for Solving the Problems In order to achieve the above object, the present invention includes means for moving the scanning means in the main scanning direction according to a predetermined timing signal, a scale disposed along the movement path of the scanning means, a mark counting means for detecting the position of the scanning means with respect to the scale; a storage means for storing in advance the deviation between forward scanning and backward scanning by the scanning means in correspondence with the scale;
Generating a scanning palmar movement signal by reading out deviation information from the storage means according to the count value obtained by the mark counting means, generating a movement timing signal based on this deviation information, and supplying this as a predetermined timing signal to the movement means. It is characterized by being equipped with a circuit.

Effect of the Invention With the above configuration, the present invention generates a movement timing signal based on the forward scanning/backward scanning deviation information that is stored in advance, and supplies this movement timing signal to the moving means. will not occur.

Embodiment FIG. 1 is a schematic perspective view showing a thermal recording apparatus to which a scanning device according to an embodiment of the present invention is applied.

In FIG. 1, the nodule is a feed roller consisting of two rollers arranged adjacent to each other. The feed roller is driven by a step motor (not shown), and conveys the recording paper 21 as a scanned medium inserted between two rollers in the direction of arrow a, which is the sub-scanning direction. Reference numerals n and 23 denote a guide shaft and a steadying shaft, respectively, which are arranged parallel to the direction of arrow C in the main scanning direction.

Note that a timing indicator (hereinafter referred to as an indicator) 50 is arranged in line with the steadying shaft. A roughly formed scale is provided between the indicators, and this forms a position mark 51. Additionally, the scale is roughly formed to reduce cost increases.

Further, I denotes a carrier, and the carrier is guided by a guide shaft n so that it can move forward and backward in the direction of arrow C, and is prevented from wobbling by a steadying shaft.

The carrier (9) is equipped with a scanner 31 as a scanning means for capturing an image signal and recording on the recording paper 21 based on the image signal, and a mark reader for reading the position mark 51. Further, the carrier is moved by a moving means 40.

The moving means 40 includes pulleys 41 and 42 arranged side by side in the direction of arrow C, a belt 43 wrapped around the pulleys 41 and 42 and connected to a carrier I at a predetermined portion, and a pulley 4
A motor 44 that drives the motor 1 and rotates it in forward and reverse directions;
4. A rotation control section 45 is provided for controlling the rotation of 4. Carrier left position detectors 3 are installed at both ends of the guide shaft ρ.
2. A carrier right position detector 33 is provided to detect when the carrier (9) reaches the end of the guide shaft n.

Further, this recording apparatus is equipped with a circuit as shown in FIG.

In FIG. 2, reference numeral 101 is a mark counter that receives a mark reading signal a from a mark reader via a terminal 107 and calculates the position of the scanning element 31.

Further, 102 is a correction value table. This correction value table 102 uses the mark reading signal a as an address, while
Corresponding to this address, mutual deviations in forward scanning and backward scanning by the scanning element 31 are stored in advance, and upon receiving address designation, deviation information corresponding to this address is output.

Further, 103 is a step pulse generation circuit, and this step pulse generation circuit 103 is composed of a timer 104 and a reference scanning timing pulse generation circuit 105. The reference scan timing pulse generation circuit 105 generates a reference scan timing pulse signal and sends it to the timer 10.
4 and to a driving section (not shown) of the scanning element 31 via a terminal 112. The timer 104 uses the correction value table 10
2 and the reference scanning timing pulse generation circuit 105, the deviation information and the reference scanning timing pulse signal are taken in from each, and the counting is started by the reference scanning timing pulse signal to perform counting according to the deviation information. When this is completed, the movement timing signal e is turned on. This movement timing signal e is outputted via the terminal 111 and inputted to the rotation control section 45 to control the motor 44 to move the carrier force.

Further, 106 is a control unit, 108 is an input terminal for a scanning start signal, and 109 is a detection signal C of the carrier left position detector 32.
110 is an input terminal for the detection signal d of the carrier right position detector, 113. 114 are terminals connected to the rotation control section 45, respectively. The control unit 106 is connected to the terminal 10
8. 109. 110. 113. 114. It is connected to a mark counter 101 and a correction value table 102, respectively. When the control unit 106 receives the ON signal of the detection signal C or the detection signal d, it outputs a clear i to the position counter 101 to clear the count of the position counter 101. Further, when the control unit 106 receives the ON signal of the detection signal C, it outputs the forward rotation signal g through the terminal 114 and the movement timing signal e through the terminal 111 to the rotation control unit 45, thereby controlling the motor power. While the carrier is rotated in the normal direction and moved to the right in the drawing by an amount corresponding to the movement timing signal e, when the ON signal of the detection signal d is input, the terminal 1
13 and a movement timing signal e through the terminal 111, respectively, to the rotation control unit 45, and the motor 44 is reversely rotated to move the carrier I toward the left in the drawing according to the timing signal e. move as much as possible. Note that the control unit 106 outputs the forward rotation signal g and the reverse rotation signal f to the correction value table 102 to control the correction value table 102.

Next, a method for correcting the deviation will be described. As shown in Figure 7,
When limited to a certain scanning section, the dot shift in that section, that is, the amount of shift and the amount of change in shift, can be considered to be practically constant. Therefore, by knowing the position of the scanning element 31, it is possible to know the deviation at that position. Therefore, the dot shift is corrected by shifting the carrier addition movement timing, that is, the timing of the drive pulse supplied to the rotation control section 45 of the motor 44, by an amount corresponding to the shift.

The operation of the recording apparatus configured as above will be explained below.

First, when the scanning start signal f is input to the control section 106 from the terminal 108, the control section 106 turns on the reverse rotation signal f.

The reversal signal f is input to the rotation control section 45 from the terminal 112. Then, the rotation control unit 45 reversely rotates the motor 44 to move the carrier force in the opposite direction (to the left in the drawing). When the carrier I reaches the left end of the guide shaft n, the carrier left position detector 32 detects the carrier addition, turns on the detection signal C, and sends it to the control section 106 via the terminal 109.

When the control unit 106 detects that the detection signal C is on, it turns off the reverse rotation signal f and turns on the forward rotation signal g. The normal rotation signal g is input to the rotation control section 45 from the terminal 114.

Then, the motor 44 rotates in the forward direction, applying carrier force in the forward direction (
(rightward in the drawing). At the same time, the control unit 106 turns on the signal i and clears the position counter 101. Preparation for scanning is completed at this stage, and then the first scanning is started.

Scanning is performed as follows.

As the carrier moves, a mark reading signal a is output to the mark counter 101, while a reference scan timing pulse signal a is output from the reference scan timing pulse generation circuit 105 to the timer 104, which starts the timer 104. be done. On the other hand, the mark counter 101 generates an address according to the mark reading signal a and outputs it to the correction value table 102. Then, deviation information corresponding to the address signal is read from the correction value table 102 and input to the timer 104. Timer 1 running
04 outputs the scanning timing signal e to the rotation control section 45 to set the position of the carrier when the time corresponding to the captured deviation information has elapsed. At the same time, the scanning element 31 is activated by a reference scanning timing pulse signal sent from the reference scanning timing pulse generation circuit 105 to the driving section of the scanning element 31.
generates heat and records. In this way, since the position is set in consideration of K and the time corresponding to the deviation before printing is performed, an appropriate image can be obtained without causing deviation in printing scan unlike in the conventional case.

Subsequently, the next mark reading signal a is input, and while the timer 104 is activated by the reference scanning timing pulse signal, the mark counter 101 performs addition processing of the mark reading signal a, and the address corresponding to the processing result is A signal is generated and output to the correction value table 102.

Then, in the same manner as described above, deviation information corresponding to the address signal is read from the correction value table 102 and this deviation information is output to the timer 104. When the timer 104 elapses according to the time, the movement timing signal e is sent to the rotation control unit 4.
5 to set the position of the carrier 30. At the same time, the scanning element 31 is heated by the reference scanning timing pulse signal and recording is performed. As a result, a proper image without deviation can be obtained.

Thereafter, recording scanning is performed in the same manner, and when the carrier force reaches the right end of the guide shaft portion, the carrier right position detector 33 detects the carrier force and turns on the detection signal d.

This detection signal d is input to the control section 106 from the terminal 110. Then, the control unit 106 turns off the normal rotation signal g,
Stop Carrier I. At the same time, the control unit 106 outputs the signal i.
is turned on and the mark counter 101 is cleared. At the same time, the recording paper 21 is moved by a predetermined amount in the sub-scanning direction by the feed roller I. When the movement is completed, the control unit 106 turns on the reverse rotation signal f and starts moving the carrier I in the opposite direction. The second scan is now started. This scan is performed in the same manner as the first scan described above.

Thereafter, from the third time onwards, scanning is performed in the same manner as described above, and the predetermined recording is completed.

In this way, since highly accurate indicators are not used, there is no increase in costs, and without the need for much time, it is possible to prevent misalignment between forward and backward scans and obtain high-quality recorded images. ing.

In this embodiment, the case where the deviation is corrected in both the forward scan and the backward scan is taken as an example, but it is also possible to use one of the scans as a reference and correct the deviation during the other scan. . In this case, it is assumed that the correction value table 102 stores shift information based on one scan.

In this embodiment, the step pulse generation circuit 103 is replaced by the timer 104 and the reference scan timing pulse generation circuit 1.
05 is taken as an example, but the configuration is not necessarily limited to this. For example, the configuration may be as shown in FIG. 3. The recording apparatus shown in FIG. 3 will be explained below. Note that the same parts as those shown in FIG. 2 are designated by the same reference numerals.

The mark counter 101 is connected to the motor 4 as in the case of FIG.
The position of the scanning element 31 is calculated by counting the input pulses to the scanning element 4, but as in the above example, the reference scanning timing pulse signal, which will be described later, may be counted for position calculation. 20 again
2 is a step pulse generation circuit and a timer 204. Reference scan timing pulse generation circuit 205 and comparison circuit 206
It consists of

The deviation information of the correction value table 102 becomes one comparison input of the comparison circuit 206. The output signal of the timer 204 is used as the other comparison input of the comparison circuit 206. Note that the timer 204 is connected to the reference scanning timing pulse generation circuit 2.
05 is activated by inputting the reference scanning timing pulse signal.

Next, the scanning operation by the recording apparatus shown in FIGS. 1 and 3 will be explained. 2 and 3 are similar except that the scanning methods are different, so only the scanning method will be described.

Scanning is performed as follows. A reference scanning timing pulse signal is outputted from the reference scanning timing pulse generation circuit 205 and inputted to the timer 204, whereby the timer 204 is started after being reset.

The output signal of the timer 204 is compared with the output value of the correction value table 102 in a comparison circuit 206. Correction value table 10
The output signal of time 204 has a value corresponding to the deviation information addressed and read out by mark counter 101, and when the output value of time 204 reaches a value corresponding to this deviation information, it is output from comparator circuit 206. The movement timing signal e is turned on, thereby setting the position of the scanning element 31, and at the same time, the scanning element 31 is energized to perform recording processing.

Then, each time the reference scanning timing pulse signal e is turned on, the timer 204 is reset and activated, and when the movement timing signal e is turned on, the position of the scanning element 31 is set in the same manner as described above, and the recording process is performed in this state. It will be done.

Incidentally, in the above-described embodiment, a recording device was used as an example, but it goes without saying that the scanning device of the present invention can be applied to a reading device.

Effects of the Invention As is clear from the above description, the present invention calculates the position of the scanning means using an index roughly set to a scale, reads the shift information of forward scanning and backward scanning from the storage means according to this calculated value, and A movement timing signal is generated from the shift information, and the movement means of the scanning means is controlled in accordance with this movement timing signal to set the position of the scanning means, and recording or reading is performed in that state. It is possible to prevent misalignment and obtain high-quality images without requiring much time.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing a thermal recording device to which a scanning device according to an embodiment of the present invention is applied, FIG. 2 is a block diagram showing a control circuit of the recording device, and FIG. 3 is a diagram showing another embodiment of the present invention. A block diagram showing a control circuit of a recording device to which the example scanning device is applied;
Fig. 4 is a schematic perspective view showing a recording device to which an example of a conventional scanning device is applied, Fig. 5 is a schematic diagram showing an example of scanning by the printing device shown in Fig. 4, and Fig. 6 shows deviation caused by the same printing device. A schematic diagram showing the state, Fig. 7 is a characteristic diagram showing the relationship between the deviation and scanning position by the same recording device, and Fig. 8 is a characteristic diagram showing the deviation when scanning is performed only in either forward scanning or backward scanning. It is. Seki...Carrier, 31...Scanner, 32...Carrier left position detector, O...Carrier right position detector, 4
0...-Moving means, 43... Belt, 44... Motor, 45... Rotation control section, 101... Mark counter, 102... Correction value table, 103, 202...
...Step pulse generation circuit, 104, 204...
Timer, 105. 205... Reference scanning timing pulse generation circuit, 106... Control section, 206... Comparison circuit. Figure 1 a Riya (90゛-u＼ :!! No.2 i?7 Preliminary j I5 Figure 6

Claims (3)

[Claims] (1) means for scanning a scanned medium according to image information;
a moving means for reciprocating the scanning means in the main scanning direction in accordance with a predetermined signal; a scale disposed along the movement path of the scanning means; and detecting the position of the scanning means in the main scanning direction according to the scale. mark counting means; storage means for storing in advance mutual deviations in forward and backward scanning by the scanning means in correspondence with the scale; and deviation information from the storage means in accordance with the position information obtained by the mark counting means. 1. A scanning device comprising: a scanning means movement signal generation circuit that reads out and generates a scanning means movement signal based on the deviation information, and supplies the signal to the movement means as the predetermined signal. (2) Scanning according to claim 1, characterized in that the scanning means movement signal generation circuit includes a counting means for performing counting according to the deviation information read from the storage means and generating the scanning means movement signal. Device. (3) A scanning means movement signal generating circuit compares the deviation information read from the storage means with a count value of a predetermined counting means, and generates a scanning means movement signal when the count value matches the deviation information. 2. A scanning device according to claim 1, further comprising a comparison means for comparing.