JP3267346B2 - Image forming method and image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention scans an original reading section using image input means such as a CCD on an original and records the image on a recording medium based on the image signal read during the scanning. The present invention relates to an image forming method and an image forming apparatus such as a copying machine and a facsimile.

[0002]

2. Description of the Related Art As a conventional image recording apparatus using a CCD or the like, there is, for example, a digital copying machine. As an image reading method in this copier, as shown in FIG. 10, a CCD which is a line reading sensor in the main scanning direction is used.
The main method is to sequentially move the original reading carriage 30 having the scanning unit 120 in the sub-scanning direction and scan it to read the entire area of the original. Then, a recording device (not shown) records on the recording medium based on the read image signal.

[0003] As shown in FIG. 11, a similar concept is adopted. However, when a document is a large-size document or a recording apparatus is for an ink jet printer, a small serial type document reading carriage 300 having a CCD 1200 is used. scanned is moved in the direction of the arrow, reads the original based on the image signal read said, some recording device (not shown) performs recording on a recording medium.

[0004]

However, in the above conventional example, the reading area and the recording area of the original are determined by the size (size) of the recording paper (recording medium) to be fed. Even where there was no, the copying would take a long time due to reading. That is, if the trimming process (for example, input with an editor) is not performed, the entire area of the recording paper size (for example, A3) is scanned , and even if the original is smaller than the recording paper, the copy time is considerably long. There is a problem that it becomes something.

Further, since the light from the pressure plate is read as a signal, there is a problem that unnecessary recording is slightly performed on the recording paper, image quality is reduced, and there is a complaint from a user.

The present invention has been made in view of the above problems, and has as its object to provide an image forming method and apparatus capable of shortening the copying time and improving the image quality.

[0007]

According to the present invention, there is provided an image forming method comprising the steps of: pressing a document placed on a platen glass with a pressure plate; and detecting a reflected light amount of light emitted from an illumination lamp. The main scanning of the carriage is performed by reciprocating the carriage provided with a document reading unit for reading the document a plurality of times in a predetermined direction on the document so that the position on the document is different. In the image forming method of performing recording by a recording head on a recording medium based on an image signal corresponding to the amount of reflected light read by the original reading unit, the amount of reflected light when the pressure plate is read by the original reading unit is set. Setting the value as a value, and at the time of the first main scanning of the carriage, the amount of reflected light read by the document reading unit is equal to the set value. Stopping the first main scan when the first scan is stopped, and determining the amount of movement of the carriage from the start of the first main scan to the stop of the scan as the amount of movement of the carriage in the main scan direction. And a step of sub-scanning the carriage in a direction orthogonal to the main scanning direction after the first main scanning in order to perform a second main scanning and a subsequent main scanning of the carriage; and A step of moving the carriage in the main scanning direction by the determined moving amount during the main scanning; and moving the recording head in the same direction as the direction in which the carriage performs the main scanning, so that the first and second carriage movements are performed. A step of performing recording by the recording head on a recording medium based on an image signal corresponding to the amount of reflected light read by the document reading unit at the time of main scanning after the first scanning; If the amount of reflected light read by the reading unit immediately after the start of the second and subsequent main scanning of the carriage is equal to the set value,
Terminating the scanning of the carriage and terminating the recording by the recording head.

Further, the image forming apparatus of the present invention includes a document reading section for pressing a document placed on a document table glass with a pressure plate and reading the document based on the amount of reflected light emitted from an illumination lamp. The carriage
The main scanning of the carriage is performed by reciprocating the document a plurality of times in a predetermined direction so that the position on the document is different, and an image corresponding to the amount of reflected light read by the document reading unit during the main scanning In an image forming apparatus that performs recording on a recording medium by a recording head based on a signal, the amount of reflected light when the pressure plate is read by the document reading unit is set as a set value, and the first main scan of the carriage is performed. Outputting a stop signal to the drive unit of the carriage to stop the first main scanning when the amount of reflected light read by the original reading unit becomes equal to the set value; The amount of movement of the carriage from the start of scanning to the stop of scanning is determined as the amount of movement of the carriage in the main scanning direction. To perform main scanning of the second and subsequent, after the first main scan, be perpendicular to the main scanning direction
A sub-scanning of the carriage in the main scanning direction, and outputting a command to a driving unit of the carriage in order to move the carriage in the main scanning direction by the determined moving amount in the second and subsequent main scannings of the carriage. Moving the recording head in the same direction as the main scanning direction of the carriage to generate an image signal corresponding to the amount of reflected light read by the document reading unit during the first and second main scanning of the carriage. If the amount of reflected light read by the reading unit is equal to the set value immediately after the second main scanning of the carriage is started, the scanning of the carriage is terminated. Control to output a stop signal to the drive unit of the carriage and to terminate the recording by the recording head. It is characterized in that it comprises a stage.

[0009]

According to the first aspect of the present invention, the difference between the reflectivity of light on the original and the reflectivity on the platen is used in advance. of light emitted et al is Ru from the illumination lamp of the carriage, to set the amount of light reflected from the pressure plate, run the original reading carriage
At the time of inspection , if the input signal value to the reading unit of the document reading carriage becomes equal to the reflected light amount, the scanning is terminated. That is, it is determined whether the input value to the reading portion of the original reading carriage is whether the image signals from the original, or the signal i.e. the amount of light reflected from the pressure plate, for the portion of the signal from the pressure plate, without scanning Does not read image signals. Accordingly, unnecessary recording is not performed on the recording medium, the recording range is set to be the same as the size of the document, the recording medium is not stained, and the recording time of one recording medium can be shortened.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a view showing a configuration of a reading apparatus according to a first embodiment of the image forming apparatus of the present invention, FIG. 2 is a top view of FIG. 1, and FIG. FIG. 2 is a control block diagram of the image forming apparatus of the present invention.

As shown in FIGS. 1 and 2, the pressing plate 1 presses the original 2 placed on an original table (original table glass) 7. The pressing plate 1 has a mirror-finished surface. It is a silver press plate. A document reading carriage 3 is provided below the document table 7. The document reading carriage 3 includes a CCD 12 and an illumination lamp 4. The original reading carriage 3 is scanned in the main scanning direction (the direction of arrow A) via the drive belt 6 by the power of a main scanning drive stepping motor (pulse motor) 5. The main scanning drive stepping motor 5, drive belt 6, and original reading carriage 3 are moved in the sub-scanning direction (arrow B direction) by a known driving mechanism (not shown) including a sub-scanning driving stepping motor 13 (see FIG. 3). Scanned. The original reading carriage 3 is moved on the original 2 by a plurality of operations in the main scanning direction and the sub-scanning direction.
Scanning, the document reading carriage 3 during the scanning
The recording device 11 (see FIG. 3), which is an ink jet printer, performs recording on a recording paper (not shown) as a recording medium based on the image signal read by the CCD 12 of FIG.

As shown in FIG. 3, the CPU 9
Of <br/> et al is Ru light emitted from the illumination lamp 4 of the document reading carriage 3, the amount of light reflected from the pressure plate 1 (see FIGS. 1 and 2) is previously set to the set value. The PC 8 applies a drive pulse to the main scan drive stepping motor 5 and includes a motor drive board capable of counting the number of drive pulses, and applies a drive pulse to the sub-scan drive stepping motor 13. Also provided is a motor drive board capable of counting the number of drive pulses. The CPU 9 judges the count number sent from the PC 8 and, if there is any condition, drives the main scanning drive stepping motor 5 and the sub-scanning drive stepping motor 13 with a drive pulse having an optimum count number. Controls PC8. During the main scanning direction and the sub-scanning direction of the scanning of the original reading carriage 3, also, CP
U9 compares the input signal values to CCD12 original reading carriage 3 and the said amount of reflected light, if they are equal, in order to terminate the scanning of the originals read carriage 3, the original reading carriage 3 A stop signal is output to the main-scanning driving stepping motor 5 and the sub-scanning driving stepping motor 13 which are the driving units, and the reading operation of the CCD 12 of the document reading carriage 3 and the recording operation of the recording device 11 are stopped. Said C
Control means 1 0 is composed of the PU9 the PC 8.

Next, the operation of this embodiment will be described.

As shown in FIG. 1, FIG. 2 and FIG. 3, when the operator places the original 2 on the original placing table 7 and makes a copy, the original reading carriage 3 The image signal of the original 2 is input to the CCD 12 (see the position), and the density of the light emitted from the illumination lamp 4 reflected by the pressure plate 1 in the portion where the original 2 is not present, ie, the non-original portion Y, (See position). Here, when the pressing plate 1 is a silver pressing plate processed into a mirror surface, the level of reflection of light from the pressing plate 1 is almost nil. That is, the light amount level is set to 256
In the case of gradation, all the input signals of R (red), G (green) and B (blue) have a level of 30 or less. A document with a high density having the same level of reflectance is not so large except for a black portion of a photograph, so that a signal from the pressure plate 1 and an image signal of the document 2 can be distinguished.
The reflection level of the white document is 248.

Therefore, in the present embodiment, when the original reading carriage 3 moves in the same direction as the recording head of the ink jet printer as the recording device 11, the original end detection in the main scanning direction (the direction of arrow A) is performed by 1 In the second scan ,
The number of drive pulses supplied to the main scanning drive stepping motor 5 up to the point when the document reading carriage 3 starts moving from the HP (home position) and receiving a signal from the pressure plate 1 is counted by the PC 8, The number of pulses is stored in the CPU 9, and the length of the document 2 in the main scanning direction is detected. CPU9 is the first scanning in the main scanning direction, in order to stop the scanning at that point,
Controls the main scan driving stepping motor 5 via the PC8, Te is <br/> relates scanning the second and subsequent main scanning direction, in order to perform the same number of pulses as the first, the main scanning through PC8 The driving stepping motor 5 is controlled. That is, the PC 8 applies drive pulses to the main scanning drive stepping motor 5 by the number of pulses stored in the CPU 9.

Next, For <br/> the scanning in the sub-scanning direction (direction of arrow B), in order to detect the original termination (see position) start point of the scanning of the carriage 3 in the main scanning direction
Immediately after starting , the input signal to the CCD 12
Equal to the set the amount of reflected light, CPU 9 is regarded where the original termination detecting the length in the sub-scanning direction of the document 2, in order to terminate the scanning of the original reading carriage 3, through PC8 subscanning While controlling the driving stepping motor 13, the recording by the recording head (not shown) of the recording device 11 is terminated, and the recording paper is discharged quickly.

(Second Embodiment) In the first embodiment, the silver plate is used as the plate.
Of course, the same processing can be performed when a pressure plate having a chromatic color such as red, green, and blue is used as in this embodiment. That is, when a red pressure plate is used, R
(Red), G (green), and B (blue) reflection signal levels of input signals are 120 or more, 20 or less, and 2
0 or less, and when a green pressure plate is used, R (red), G
The input signal levels of (green) and B (blue) are respectively 20 or less, 120 or more, and 20 or less. When a blue pressure plate is used, the input of R (red), G (green) and B (blue) By setting the signal level to 20 or less, 20 or less, or 120 or more, it is possible to distinguish between the input signal to the CCD and the signal from the pressure plate or the image signal of the original. Other configurations are the same as those of the first embodiment.

(Third Embodiment) When the pressing plate is a white plate, the following processing can be considered. FIG. 4 is a diagram for explaining the operation of the reading apparatus according to the third embodiment of the image forming apparatus of the present invention.

As shown in FIGS. 3 and 4, first, the white level 255 of the pressure plate is input to the CPU 9, and the first run is performed.
査 sometimes keep CPU9 on to store the point at which the input signal becomes the white level from the other colors of the signal starting a movement pulse number of driving stepping motor 5 (see position).
Similarly, the same sequence is repeated about the third time (position, refer to), and the CPU 9 regards the point (here, position) of the drive pulse which is the largest in the three scans as the document edge, and determines the length of the document 2 in the main scanning direction. And the second and subsequent runs
The inspection ends at that point. The same white level detection is performed during the document reading by the CCD 12 for the fourth and subsequent times, and when the point of the white level detection is the movement start point of the document reading carriage 3 twice (position,
), The CPU 9 regards the point (the position here) as the end of the original in the sub-scanning direction, detects the length of the original 2, and
Thereafter, the CPU 9 outputs a stop signal to the main-scanning driving stepping motor 5 and the sub-scanning driving stepping motor 13 to stop the movement of the original reading carriage 3, and to promptly perform recording on the recording device 11. The paper (not shown) is discharged. Thus, the copy is completed. Other operations are the same as in the first embodiment.

[0021] (First Example) FIG. 5 is a diagram for explaining the operation of the reading device of the first reference example of the image forming apparatus, FIG. 6, the first ginseng
Is a flow chart for explaining the operation of the reader considered example.

In the first reference example , as in the first, second, and third embodiments, the size of the original is detected by utilizing the difference between the reflectance of the original and the reflectance of the pressure plate. However, in the first reference example, the detection is performed not at the time of regular scanning but at the time of preliminary scanning prior to regular scanning.

[0023]

[Table 1] In the first to third embodiments and the first reference example , the ratio of the input signal value (light amount of light) to the CCD with respect to the reflectance of light between the original and the silver pressing plate and the amount of light reflected from the silver pressing plate. The detection rate is approximately as shown in Table 1. According to Table 1, when the detection rate is 50% or more, the document area and the detection rate are 50%.
%, It can be regarded as a non-document area.

As shown in FIG. 5, the CPU 9 stores the detection rate of the non-document area in advance, and the CPU 9 determines the detection rate of the CCD 12 during the pre-scanning in the main scanning direction. Is less than 50%, the point is regarded as the end of the document, and the length of the document is detected.

As shown in FIGS. 3, 5, and 6, when a copy start key (not shown) is pressed, the main scanning drive stepping motor 5 is used to detect the size of the original, as indicated by the arrow in the main scanning direction. Is performed (step 14). If the detection rate of the CCD 12 is less than 50% based on the difference in reflectance between the silver press plate 1 and the original 2 (step 15), the PC 8 continues the main scanning until then. The CPU 9 counts the number of drive pulses supplied to the drive stepping motor 5, stores the number of pulses, regards the point as the document edge, and detects the length of the document 2 in the main scanning direction . After the actual copying, at the time of normal scanning, the PC 8 supplies the same number of driving pulses as the driving pulses to the main scanning driving stepping motor 5 by a command from the CPU 9 so that the original reading carriage 3 (Document area X)
The reading of the original by the recording device 12 and the recording on the recording paper by the recording device 11 are performed (step 17), and the reading operation and the recording operation are completed from the place where the original is gone (non-original area), and the paper is discharged. On the other hand, the detection rate by the CCD 12 is 5
If not less than 0% (step 15), the entire surface of the document 2 is read by the CCD 12 during normal scanning (step 16).

( Second Reference Example) FIG. 7 is a diagram for explaining the operation of a reading apparatus according to a second reference example of the image forming apparatus. In the first reference example, the preliminary scanning is performed in the main scanning direction .
In Reference Example 2, the preliminary scanning 19 and 20 of the original reading carriage 3 in the main scanning direction and the sub-scanning direction are sequentially performed once each, and the length of the original 2 in the main and sub-scanning directions is detected. It performs scanning. Other operations are the same as those of the first reference example.

( Third Reference Example) FIG. 8 is a view for explaining the operation of a reading device according to a third reference example of the image forming apparatus. FIG. 9 is a diagram illustrating the reading device of the third reference example. It is a schematic diagram for demonstrating operation | movement.
For example, if the maximum size document is A4, the angle θ is determined based on the diagonal line of A4. The CPU 9 controls the main scanning driving stepping motor 5 and the sub-scanning driving stepping motor (not shown) via the PC 8 so that the preliminary scanning 21 of the document reading carriage 3 is read obliquely at an angle θ. Of the original size is detected. Other operations are the same as those of the first embodiment.

[0028]

[Table 2] Table 2 is a table showing a method of determining a document size. In the case of a standard document, since the length of the diagonal line is determined, the length determined as the document at the time of the preliminary scanning exceeds, for example, 260 mm and 315 mm.
mm or less, the reading range of the original 2 during scanning is set to B
5 is assumed.

[0029]

Since the present invention is configured as described above, the following effects can be obtained.

According to the first aspect of the present invention, it is determined whether an input signal to the original reading unit is a signal from a pressure plate or a signal from an original to prevent unnecessary scanning in a non-original area. By
It is possible to increase the copying speed, to improve the efficiency of copying by the operator, and to eliminate unnecessary stains on the recording medium without making unnecessary recording .

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a reading device according to a first embodiment of an image forming apparatus (copier) of the present invention.

FIG. 2 is a top view of FIG.

FIG. 3 is a control block diagram of the image forming apparatus of the present invention.

FIG. 4 is a diagram for explaining the operation of a reading device according to a third embodiment of the image forming apparatus of the present invention.

FIG. 5 is a diagram for explaining the operation of the reading device according to the first reference example of the image forming apparatus.

FIG. 6 is a flowchart for explaining the operation of the reading device according to the first reference example of the image forming apparatus.

FIG. 7 is a diagram illustrating an operation of a reading device according to a second reference example of the image forming apparatus.

FIG. 8 is a diagram illustrating an operation of a reading device according to a third reference example of the image forming apparatus.

FIG. 9 is a schematic diagram for explaining an operation of the reading device of the third reference example .

FIG. 10 is a schematic perspective view of a reading device of a conventional image forming apparatus.

FIG. 11 is a schematic perspective view of a reading device of another conventional image forming apparatus.

[Explanation of symbols]

 Reference Signs List 1 pressure plate 2 original 3 original reading carriage 4 illumination lamp 5 main scanning drive stepping motor 6 drive belt 7 original placing table (original table glass) 8 PC 9 CPU 10 control means 11 recording device (inkjet printer) 12 CCD (reading) 13) Stepping motor for sub-scanning drive 14, 15, 16, 17 Step 19, 20, 21 Pre-scanning HP Home position X Original area Y Non-original area A Main scanning direction B Sub-scanning direction

Continuation of the front page (56) References JP-A-63-5659 (JP, A) JP-A-4-25279 (JP, A) JP-A-61-32183 (JP, A) JP-A-61-78276 (JP) JP-A-3-165660 (JP, A) JP-A-59-225669 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 1/04-1/207

Claims (2)

(57) [Claims] An original placed on a platen glass is pressed by a pressure plate, and a carriage provided with an original reading unit for reading the original based on the amount of reflected light emitted from an illumination lamp is provided on the original. The main scanning of the carriage is performed by reciprocating on the document a plurality of times in a predetermined direction so that the positions are different, and based on an image signal corresponding to the amount of reflected light read by the document reading unit during the main scanning. In an image forming method for performing recording by a recording head on a recording medium, a step of setting a reflected light amount when the pressure plate is read by the document reading unit as a set value; When the amount of reflected light read by the document reading unit becomes equal to the set value, the first main scanning is stopped, and the first main scanning is performed. Determining the amount of movement of the carriage from the start of scanning to the stop of scanning in the main scanning direction as the amount of movement of the carriage; and performing the second main scanning of the carriage in the first main scanning direction. After the scanning, a step of sub-scanning the carriage in a direction orthogonal to the main scanning direction; and in the second and subsequent main scanning of the carriage, moving the carriage in the main scanning direction by the determined moving amount. Moving the recording head in the same direction as the main scanning direction of the carriage, and performing the first and second movements of the carriage.
A step of performing recording by the recording head on a recording medium based on an image signal corresponding to the amount of reflected light read by the document reading unit at the time of the main scanning of the second and subsequent times; and starting the second and subsequent main scanning of the carriage. Immediately after the reflected light amount read by the reading unit is equal to the set value, ending the scanning of the carriage and ending the recording by the recording head. A carriage provided with a document reading unit for reading the document based on the amount of reflection of light emitted from an illumination lamp by pressing a document placed on a platen glass with a pressure plate; The main scanning of the carriage is performed by reciprocating on the document a plurality of times in a predetermined direction so that the positions are different, and based on an image signal corresponding to the amount of reflected light read by the document reading unit during the main scanning. In an image forming apparatus for performing recording on a recording medium by a recording head, the amount of reflected light when the pressure plate is read by the document reading unit is set as a set value, and the document is read during the first main scanning of the carriage. When the amount of reflected light read by the unit becomes equal to the set value, the carriage is driven to stop the first main scanning. Outputs a stop signal to the part, the amount of movement of the carriage to stop scanning from a scanning start in the first main scan,
In order to determine the amount of movement of the carriage in the main scanning direction and perform main scanning for the second and subsequent times,
After the first main scan, the carriage is sub-scanned in a direction orthogonal to the main scan direction, and the carriage is moved in the main scan direction by the determined movement amount during the second and subsequent main scans of the carriage. The carriage outputs a command to the drive unit of the carriage, moves the recording head in the same direction as the main scanning direction of the carriage, and performs the original document at the time of the first and second main scanning of the carriage. The recording head performs recording on the recording medium based on the image signal corresponding to the reflected light amount read by the reading unit, and the reflected light amount read by the reading unit immediately after the start of the main scanning of the carriage for the second time or later is the If it is equal to the set value, a stop signal is output to the drive unit of the carriage to end the scanning of the carriage, and An image forming apparatus characterized by comprising control means for terminating the recording by the serial recording head.