JP2004237573A - Image forming device - Google Patents

Abstract

Provided is an image forming apparatus that can suppress printing outside a recording medium range in consideration of erroneous detection of a recording medium size.
A sheet is transported to a predetermined position (S11), and it is determined whether the transport of the sheet is completed (S12). If the paper feeding has been completed (S12; Y), a carriage reference position (P = 0) is detected (S13). Next, driving of the carriage is started (S14), and it is determined whether or not the output of the paper sensor has changed to ON (S15). If it has changed to ON (S15; Y), the right end position Pr is stored (S16). Subsequently, it is determined whether or not the output of the paper sensor has changed to OFF (S17). When the output of the paper sensor changes to OFF (S17; Y), the left end position Pl is stored (S18). Then, the carriage is returned to the cap position (S19), and when the movement of the carriage is completed (Y in S20), the process ends.
[Selection] Fig. 10

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus such as an ink jet printer which is a non-impact printer of a type that prints by printing a special ink on a recording medium.
[0002]
[Prior art]
2. Description of the Related Art In recent years, color printers such as ink jet printers, which are non-impact printers of the type that prints by printing a dedicated ink from a nozzle of a print head onto printer paper, have become widespread.
In particular, since the size of the print head of an ink jet printer can be reduced, various types of small and low-cost color printers have been developed and have been widely used by individual users.
[0003]
By the way, when an image is formed on a recording medium using such an ink jet printer, ink may be sprayed out of the range of the recording medium due to distortion or displacement of the recording medium.
Printing outside such a recording medium range wastes recording materials such as ink.
Further, depending on the components of the image forming apparatus, printing outside the range of the recording medium may damage the machine.
[0004]
In particular, an image forming apparatus or the like that conveys a recording medium by a belt has a belt conveyance performance (e.g., an electrostatic adsorption method) by printing outside the recording medium range and by adhering and sticking a recording material such as ink to the belt. Of the recording medium) and may affect the recording medium conveyance performance.
Various techniques for solving such a problem in the image forming apparatus are disclosed, including the following patent document.
[Patent Document 1]
JP-A-2001-347653
Japanese Patent Application Laid-Open No. H11-163873 discloses a technique for detecting a width of a recording medium to be conveyed and restricting printing outside a recording medium range, thereby executing an appropriate image forming process.
[0005]
[Problems to be solved by the invention]
However, in order to detect the width of the recording medium, it is necessary to move the print head larger than the actual width of the recording medium, so that the processing performance (speed) of image formation may be reduced.
Further, if the detection of the width of the recording medium is not performed during the main scanning with emphasis on the image forming processing performance, the recording medium may be displaced due to external factors and the shape of the recording medium may not be predicted. There is a possibility that printing outside the range cannot be suppressed.
[0006]
Further, when erroneous detection of the width of the recording medium is considered, the method of detecting the width of the recording medium disclosed in Patent Document 1 is not sufficient. If the printing is continued ignoring the erroneous detection of the recording medium, the printing result is not intended by the user, and there is a possibility that the recording material may be wasted.
Therefore, the present invention compares the information such as the recording medium size specified by the user with the size of the recording medium actually detected, thereby allowing the recording medium to be out of the range of the recording medium in consideration of the erroneous detection of the recording medium size. An object of the present invention is to provide an image forming apparatus capable of performing print suppression processing.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, in an image forming apparatus that forms an image on a recording medium by spraying a recording material from nozzles provided on a head, an input of a designated size of the recording medium set in the image forming apparatus is received. Receiving means, detecting means for measuring the size of the recording medium set in the image forming apparatus and detecting the actual size, the designated size received by the receiving means, and the actual measurement detected by the detecting means And a comparison unit that compares the size and the comparison unit. If the difference between the designated size and the measured size is smaller than a predetermined value, a printing process is performed on the recording medium based on the measured size. Mask processing means for performing a mask processing for setting an area where no printing is to be performed and an area for performing the printing processing, and the printing which is set by the mask processing means. And printing means for performing only printing in a region subjected to physical, by providing to achieve the object.
According to a second aspect of the present invention, when the difference between the designated size and the actually measured size is larger than a predetermined value as a result of the comparison by the comparing means, the image forming apparatus is set to the image forming apparatus. Re-detecting means for measuring the size of the recording medium again and detecting the re-measured size,
The comparing means achieves the object by comparing the designated size received by the receiving means with the re-measured size detected by the re-detecting means.
According to a third aspect of the present invention, in the first aspect of the present invention, when a difference between the designated size and the actually measured size is larger than a predetermined value as a result of the comparison by the comparing means, the image forming apparatus may The above purpose is achieved by stopping the processing.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS.
FIG. 1 is a perspective view of a mechanism section of the ink jet recording apparatus according to the present embodiment.
FIG. 2 is a side view of a mechanism section of the ink jet recording apparatus according to the present embodiment.
As shown in FIGS. 1 and 2, the ink jet recording apparatus includes a main body 1, a carriage 13 movable in the main scanning direction, a head 14 including an ink jet head mounted on the carriage 13, and an ink for supplying ink to the head 14. The printing mechanism unit 2 including the cartridge 15 and the like is housed therein.
At the lower part of the main body 1, a paper feed cassette 4 capable of loading a large number of papers 3 can be detachably inserted from the front side, and a manual feed tray 5 for manually feeding the papers 3 is opened. After taking in the paper 3 fed from the paper feed cassette 4 or the manual feed tray 5 and forming a required image by the printing mechanism 2, the paper is discharged to the paper discharge tray 6 mounted on the rear side. It is supposed to be.
[0009]
The printing mechanism 2 holds a carriage 13 slidably in a main scanning direction (a direction perpendicular to the paper of FIG. 2) by a main guide rod 11 which is a guide member which is laterally mounted on left and right side plates (not shown). Mounts an ink jet head 14 for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (Bk) with the ink droplet ejection direction facing downward, A sub-tank 12 for supplying ink of each color to the head 14 is mounted on the upper side.
The sub-tanks 12 of each color are connected to an ink cartridge 15 that is mounted so as to be exchangeable via an ink supply tube 16 so that ink is supplied from the ink cartridge 15.
[0010]
The carriage 13 is slidably fitted on the main guide rod 11 on the rear side (downstream side in the sheet conveying direction). In order to move and scan the carriage 13 in the main scanning direction, a timing belt 20 is stretched between a driving pulley 18 and a driven pulley 19 that are driven to rotate by a main scanning motor 17. It is fixed to.
Although the heads 14 of the respective colors are used here as the recording heads, a single head having nozzles for ejecting ink droplets of the respective colors may be used.
Further, the ink jet head used as the head 14 is a piezo type in which ink is pressurized through a vibration plate forming a liquid chamber (ink flow path) wall surface by an electromechanical transducer such as a piezoelectric element, and film boiling by a heating resistor. Bubble type, which pressurizes ink by generating bubbles, or electrostatic, which presses ink by displacing the vibrating plate with electrostatic force between a vibrating plate forming the ink flow path wall surface and an electrode facing the vibrating plate. Type, etc. can be used. In this embodiment, an explanation will be given using an electrostatic inkjet head.
[0011]
The ink jet recording apparatus includes a paper feed roller 21 and a friction pad 22 that separate and feed the paper 3 from the paper feed cassette 4, a guide member 23 that guides the paper 3, and a transport roller that reverses and transports the fed paper 3. The paper 3 set in the paper feed cassette 4 is transferred to the head 14 by using a transport roller 25 pressed against the peripheral surface of the transport roller 24 and a tip roller 26 that defines an angle at which the paper 3 is sent out from the transport roller 24. To the lower side of
The transport roller 24 is driven to rotate by a sub-scanning motor 27 via a gear train.
[0012]
The ink jet recording apparatus is provided with an electrostatic transport belt 29 that guides the paper 3 sent out from the transport rollers 24 to the lower side of the head 14 in accordance with the movement range of the carriage 13 in the main scanning direction.
The electrostatic transport belt 29 charges the transported paper 3 by being charged using the charger 30, and can keep the paper surface and the head surface parallel. On the downstream side of the electrostatic transport belt 29 in the paper transport direction, a paper discharge roller 33 for delivering the paper 3 to the paper discharge tray 6 is provided.
Further, a maintenance and recovery mechanism 37 for maintaining and recovering the reliability of the head 14 is disposed on the right end side in the moving direction of the carriage 13. During printing standby, the carriage 13 is moved toward the maintenance and recovery mechanism 37 so that the head 14 is capped by capping means or the like.
[0013]
Next, a process of detecting an end position of a sheet as a recording medium and applying an image mask in the ink jet recording apparatus will be described.
FIG. 3 is a front view of the ink jet printer.
Two heads 14a, 14b are mounted on the carriage 13, and two nozzle rows 103, 104 and 105, 106 are arranged on the heads 14a, 14b, respectively. The ink is ejected from.
[0014]
As shown in FIG. 3, when the carriage 13 is located at the end of the ink jet recording apparatus, the head 14a is covered by the cap 107, and the head 14b is covered by the suction / cap 108. The ink is protected from clogging.
The paper detection sensor 109 is installed on the left side when viewed from the front of the carriage. The sheet detection sensor 109 has a light emitting element and a light receiving element, and functions to detect the presence or absence of a sheet from reflection of light.
The electrostatic transport belt 29 functions to adsorb the paper 3 by static electricity, thereby transporting the paper while maintaining the flatness of the paper.
[0015]
FIGS. 4 and 5 are diagrams showing the configuration of the sheet detection sensor 109. FIG.
As shown in FIG. 4, in the sheet detection sensor 109, the light emitted from the light emitting unit 301 is reflected on the sheet 3 on the electrostatic transport belt 29, and the reflected light is received by the light receiving unit 302. .
Further, as shown in FIG. 5, when the paper detection sensor 109 is not positioned on the paper, the light emitted from the light emitting unit 301 is applied to the electrostatic transport belt 29 coated with a dark color. The light receiving unit 302 cannot obtain reflected light. In this manner, the presence or absence of the paper 3 can be detected based on the presence or absence of the sensitivity in the light receiving unit 302.
[0016]
FIG. 6 is a side view of the mechanism of the inkjet recording apparatus when the carriage 13 moves in the main scanning positive direction from the position of the capping 107.
FIG. 7 is a side view of the mechanism of the ink jet recording apparatus when the carriage 13 has moved to the right end detection position of the sheet 3.
FIG. 8 is a side view of the mechanism of the inkjet recording apparatus when the carriage 13 has moved to the position where the left end of the sheet 3 is detected.
As shown in FIG. 6, the sheet detection sensor 109 does not detect the sheet 3 at the position of the carriage 13.
Then, when the carriage 13 further moves in the main scanning positive direction (the left direction in the figure), the sheet detection sensor 109 detects the right end of the sheet 3 as shown in FIG.
When the sheet further advances in the main scanning positive direction (the left direction in the figure), the sheet detection sensor 109 detects the left end of the sheet 3 as shown in FIG.
[0017]
FIG. 9 is a block diagram illustrating a configuration of a control system of the inkjet recording apparatus according to the present embodiment.
As shown in FIG. 9, the control system of the inkjet recording apparatus includes a paper detection sensor 109, a CPU (central processing unit) 500, a non-volatile memory 501, an image memory 502, an operation unit 503, a head 504, a main scanning motor operation command. Circuit 506, main scanning motor driver 507, main scanning motor 508, sub-scanning motor operation command circuit 509, sub-scanning motor driver 510, sub-scanning motor 511, paper feed clutch driver 512, paper feed clutch 513, main scan encoder 514, extension The circuit 520 includes an image mask circuit 521 and an I / F (interface) circuit 522.
[0018]
The CPU 500 drives the sub-scanning motor 512 via the sub-scanning motor driver 510 and the paper feed clutch 513 via the paper feed clutch driver 512 by giving instructions to the sub-scanning motor operation command circuit 509 and the paper feed clutch driver 511. Then, the paper is fed from the paper feed cassette 4 (FIG. 2) and transported.
Further, the CPU 500 drives the main scanning motor 508 via the main scanning motor driver 507 by giving a command to the main scanning motor operation command circuit 506 to move the carriage 13 in the main scanning direction.
At this time, the CPU 500 can recognize the position of the carriage 13 by reading out the output signal of the main scanning encoder 514 via the main scanning motor command circuit.
[0019]
The operation unit 503 includes an LCD (Liquid Crystal Display), an LED (Light Emitting Diode), and the like, and has a function of notifying an operator of the state of the inkjet recording apparatus according to a command from the CPU 500.
The nonvolatile memory 501 can hold written data even when the power is turned off, and is configured by, for example, an SRAM (static random access memory) or an E2PROM (electrically erasable memory) with a built-in battery. ing.
An image memory 502 is a memory in which image data to be printed is stored, and is configured by, for example, an SDRAM.
[0020]
The image data read from the image memory 502 is decompressed by the decompression circuit 520 from the compressed state, and then subjected to a process of whether or not to be masked by the image mask circuit 521. Then, the data subjected to the mask processing is transmitted to the head 504 via the I / F circuit 522.
Here, the decompression circuits 520, the image mask circuits 521, and the I / F circuits 522 are prepared for the number of nozzle rows, respectively, and can process data of each nozzle row in parallel.
An output signal of the main scanning encoder 514 is input to the I / F circuit, and image data is sent to the head in synchronization with the main scanning position of the carriage.
Further, the CPU 500 can mask an output image at an arbitrary timing by giving a command to the image mask circuit 521.
[0021]
Next, a method for detecting the edge of the sheet 3 as a recording medium in the ink jet recording apparatus according to the present embodiment will be described.
FIG. 10 is a flowchart illustrating a procedure of a process of detecting an end of the sheet 3 as a recording medium.
First, the CPU 500 feeds and transports the paper 3 to a predetermined position on the transport belt (step 11).
Next, the CPU 500 determines whether or not the paper 3 has been fed (step 12).
If the feeding of the paper 3 has not been completed (step 12; N), the paper 3 is continuously fed.
On the other hand, when the paper 3 has been fed (step 12; Y), the CPU 500 detects the position of the carriage 13 and recognizes the detected position as a reference point (P = 0) (step 13). .
[0022]
The CPU 500 starts driving the carriage 13 and moves the carriage 13 in the main scanning positive direction (step 14).
Then, CPU 500 determines whether or not the output of paper sensor 109 has changed to ON (step 15).
If the output of the paper sensor 109 has not changed to ON (step 15; N), the CPU 500 continues to move the carriage 13.
On the other hand, when the output of the paper sensor 109 changes to ON (step 15; Y), the CPU 500 reads the position of the carriage 13 at the timing when the output of the paper sensor 109 is turned ON, and stores that position as the right end position Pr of the paper. (Step 16).
[0023]
Next, CPU 500 determines whether or not the output of paper sensor 109 has changed to OFF (step 17).
If the output of the paper sensor 109 has not changed to OFF (step 17; N), the CPU 500 continues to move the carriage 13.
On the other hand, if the output of the paper sensor 109 changes to OFF (Step 17; Y), the CPU 500 reads the position of the carriage 13 at the timing when the output of the paper sensor 109 is turned OFF, and stores the position as the left end position Pl of the paper. (Step 18).
[0024]
After detecting the left and right end positions of the sheet 3 in this way, the carriage 13 is driven in the negative direction of the main scanning to return to the capping position (step 19).
Then, the CPU 500 determines whether or not the movement of the carriage 13 has been completed (step 20).
If the movement of the carriage 13 is not completed (Step 20; N), the carriage 13 is moved continuously.
On the other hand, when the movement of the carriage 13 has been completed (Step 20; Y), the head 14 of the carriage 13 is capped and the process ends.
The process of detecting the edge of the sheet 3 as such a recording medium may be performed simultaneously with the printing operation.
[0025]
FIG. 11 is a diagram showing a positional relationship between the sheet detection sensor 109 and each of the nozzle arrays 103 to 106.
S1 is the distance between the paper detection sensor 109 and the nozzle row 106, S2 is the distance between the paper detection sensor 109 and the nozzle row 105, S3 is the distance between the paper detection sensor 109 and the nozzle row 104, S4 is the paper detection sensor 109 and the nozzle The distance between the columns 103 is shown.
[0026]
12 and 13 are flowcharts showing the procedure of the image masking process.
Here, the coordinates Pms at which image unmasking is started are set at the right end Pr of the sheet 3, the coordinates Pme at which image unmasking is ended are set at the left end Pl of the sheet 3, the distance between the sheet detection sensor 109 and the nozzle array 106 is S 1, The distance between the detection sensor 109 and the nozzle row 105 is defined as S2, the distance between the paper detection sensor 109 and the nozzle row 104 is defined as S3, and the distance between the paper detection sensor 109 and the nozzle row 103 is defined as S4.
Based on the position information defined in this way, the arithmetic expressions of the mask release start coordinates and the mask release end coordinates in each nozzle row are shown below.
The mask release start coordinates of the nozzle array 106 are Ps1 = Pr + S1,
The mask release start coordinates of the nozzle row 105 are Ps2 = Pr + S2,
The mask release start coordinates of the nozzle row 104 are Ps3 = Pr + S3,
The mask release start coordinates of the nozzle array 103 are Ps4 = Pr + S4,
The mask release end coordinates of the nozzle array 106 are Pe1 = Pl + S1,
The mask release end coordinates of the nozzle row 105 are Pe2 = Pl + S2,
The mask release end coordinates of the nozzle array 104 are Pe3 = Pl + S3,
The mask release end coordinates of the nozzle row 103 are Pe4 = Pl + S4.
[0027]
First, the CPU 500 feeds and transports the paper 3 to a predetermined position on the transport belt (step 21).
Next, the CPU 500 determines whether or not the paper 3 has been fed (step 22).
If the feeding of the paper 3 has not been completed (Step 22; N), the paper 3 is continuously fed.
On the other hand, when the feeding of the paper 3 is completed (Step 22; Y), the CPU 500 enables the image masks of all the nozzle rows (Step 23), and thereafter, detects the position of the carriage 13 and detects the position. The position is recognized as a reference point (P = 0) (step 24).
The CPU 500 starts driving the carriage 13 and moves the carriage 13 in the main scanning positive direction (step 25).
[0028]
Next, the CPU 500 compares the value of P indicating the current position of the carriage 13 with the value of Ps4 indicating the mask release start coordinates of the nozzle row 103, and determines whether P is greater than Ps4 (P> Ps4). A judgment is made (step 26).
When P is smaller than Ps4 (P <Ps4) (Step 26; N), the carriage 13 is moved continuously.
On the other hand, if P is greater than Ps4 (P> Ps4) (Step 26; Y), the CPU 500 releases the image mask of the nozzle array 103 (Step 27). That is, at the position where the carriage position P has reached Ps4, the image mask of the nozzle row 103 is released.
[0029]
Next, the CPU 500 compares the value of P indicating the current position of the carriage 13 with the value of Ps3 indicating the mask release start coordinates of the nozzle row 104, and determines whether P is greater than Ps3 (P> Ps3). A judgment is made (step 28).
When P is smaller than Ps3 (P <Ps3) (Step 28; N), the carriage 13 is moved continuously.
On the other hand, if P is larger than Ps3 (P> Ps3) (Step 28; Y), the CPU 500 releases the image mask of the nozzle array 104 (Step 29). That is, at the position where the carriage position P has reached Ps3, the image mask of the nozzle array 104 is released.
[0030]
Next, the CPU 500 compares the value of P indicating the current position of the carriage 13 with the value of Ps2 indicating the mask release start coordinates of the nozzle row 105, and determines whether P is greater than Ps2 (P> Ps2). A decision is made (step 30).
When P is smaller than Ps2 (P <Ps2) (Step 30; N), the carriage 13 is moved continuously.
On the other hand, when P is larger than Ps2 (P> Ps2) (Step 30; Y), the CPU 500 releases the image mask of the nozzle array 105 (Step 31). That is, at the position where the carriage position P has reached Ps2, the image mask of the nozzle row 105 is released.
[0031]
Next, the CPU 500 compares the value of P indicating the current position of the carriage 13 with the value of Ps1 indicating the mask release start coordinates of the nozzle row 106, and determines whether P is greater than Ps1 (P> Ps1). A decision is made (step 32).
When P is smaller than Ps1 (P <Ps1) (Step 32; N), the carriage 13 is moved continuously.
On the other hand, if P is greater than Ps1 (P> Ps1) (step 32; Y), the CPU 500 releases the image mask of the nozzle array 106 (step 33). That is, at the position where the carriage position P has reached Ps1, the image mask of the nozzle row 106 is released.
[0032]
Next, the CPU 500 compares the value of P indicating the current position of the carriage 13 with the value of Pe4 indicating the unmasking end coordinates of the nozzle row 103, and determines whether P is greater than Pe4 (P> Pe4). A decision is made (step 34).
When P is smaller than Pe4 (P <Pe4) (Step 34; N), the carriage 13 is moved continuously.
On the other hand, if P is larger than Pe4 (P> Pe4) (Step 34; Y), the CPU 500 enables the image mask of the nozzle array 103 (Step 35). That is, at the position where the carriage position P has reached Pe4, the image mask of the nozzle row 103 is enabled.
[0033]
Next, the CPU 500 compares the value of P indicating the current position of the carriage 13 with the value of Pe3 indicating the unmasking end coordinates of the nozzle row 104, and determines whether P is larger than Pe3 (P> Pe3). A decision is made (step 36).
When P is smaller than Pe3 (P <Pe3) (Step 36; N), the carriage 13 is moved continuously.
On the other hand, if P is greater than Pe3 (P> Pe3) (Step 36; Y), the CPU 500 enables the image mask of the nozzle array 104 (Step 37). That is, at the position where the carriage position P has reached Pe3, the image mask of the nozzle row 104 is enabled.
[0034]
Next, the CPU 500 compares the value of P indicating the current position of the carriage 13 with the value of Pe2 indicating the unmasking end coordinates of the nozzle row 105, and determines whether P is larger than Pe2 (P> Pe2). A judgment is made (step 38).
When P is smaller than Pe2 (P <Pe2) (Step 38; N), the carriage 13 is moved continuously.
On the other hand, when P is larger than Pe2 (P> Pe2) (Step 38; Y), the CPU 500 enables the image mask of the nozzle array 105 (Step 39). That is, at the position where the carriage position P has reached Pe2, the image mask of the nozzle row 105 is made effective.
[0035]
Next, the CPU 500 compares the value of P indicating the current position of the carriage 13 with the value of Pe1 indicating the unmasking end coordinates of the nozzle row 106, and determines whether P is greater than Pe1 (P> Pe1). A decision is made (step 40).
When P is smaller than Pe1 (P <Pe1) (step 40; N), the carriage 13 is moved continuously.
On the other hand, when P is larger than Pe1 (P> Pe1) (step 40; Y), the CPU 500 enables the image mask of the nozzle row 106 (step 41). That is, at the position where the carriage position P has reached Pe2, the image mask of the nozzle row 106 is enabled.
[0036]
After the image mask of the nozzle row 106 is made valid, the carriage 13 is driven in the negative direction of the main scanning to return to the capping position (step 42).
Then, the CPU 500 determines whether or not the movement of the carriage 13 has been completed (step 43).
If the movement of the carriage 13 has not been completed (Step 43; N), the carriage 13 continues to be moved.
On the other hand, when the movement of the carriage 13 has been completed (Step 43; Y), the head 14 of the carriage 13 is capped and the process ends.
[0037]
In the section from the start to the end of the image mask release of each nozzle row, the image masking circuit 521 does not perform the process of masking the image, and the data supplied to the head 14 during that time is ejected from the nozzle rows 103 to 106 as an effective image. Is done.
Conversely, in a section where the mask of each nozzle row is not released, a process of masking the image is performed by the image mask circuit 521, during which white data is given to the head and ink is not ejected from the nozzle row. It has become.
[0038]
In the above-described image masking process, the CPU 500 controls the image mask circuit 521 in real time while monitoring the position of the carriage 13, but a circuit using a main scanning encoder signal as shown in FIG. By using this, the processing load on the CPU 500 can be reduced.
Specifically, the CPU 500 writes the mask release start position in the register 552 in advance.
When the carriage 13 starts moving, the main scanning encoder signal is input to the main scanning counter 551, and the position of the carriage 13 is measured by the main scanning counter 551.
Here, when the position of the carriage 13 measured by the main scanning counter 551 matches the position written in the register 552, the comparator 553 outputs a mask release start signal.
This mask release start signal is input to the image mask circuit 521, and the image mask release is started.
[0039]
The termination of the image mask release can also be realized by using a circuit having exactly the same configuration.
Specifically, when the carriage reaches the image mask release end position, a mask release end signal is output.
This mask release end signal is input to the image mask circuit 521, and the image mask release ends.
[0040]
(First embodiment)
FIG. 15 is a flowchart illustrating a procedure of the image forming process in the first embodiment.
FIG. 16 is a diagram showing the moving direction of the carriage 13 in the first embodiment. In practice, the paper is conveyed and printing is performed. Here, the movement of the carriage 13 is shown relative to the paper in order to make the main scanning operation on the paper easy to understand.
First, in the ink jet recording apparatus, a user specifies a predetermined size of paper as a recording medium (step 51). Then, the user inputs the specified paper size information from the operation unit 503.
Then, the ink jet recording apparatus moves the carriage 13 to detect the width of the sheet 3 set in the ink jet recording apparatus (Step 52). The detection of the width of the sheet 3 is performed by the above-described method using the sheet detection sensor 109.
[0041]
Next, the inkjet recording apparatus compares the detected size of the width of the paper 3 detected by the paper detection sensor 109 with the specified size specified by the user, and calculates the difference between these sizes. Is larger than a predetermined value (for example, 5 mm) that is set in advance (step 53).
If the difference is larger than the predetermined value (step 53; Y), the ink jet recording apparatus moves the carriage 13 again to detect the width of the sheet 3 set in the ink jet recording apparatus (step 54). Proceed to step 55.
On the other hand, when the difference is smaller than the predetermined value (Step 53; N), the main scanning printing is performed while performing the mask processing based on the detected width of the sheet 3 (Step 55).
Then, it is confirmed that all the printing processes in the page have been completed (step 56), and the process is terminated.
[0042]
(Second embodiment)
FIG. 17 is a flowchart illustrating the procedure of the image forming process in the second embodiment.
FIG. 18 is a diagram showing the moving direction of the carriage 13 in the second embodiment. Actually, printing is performed while a sheet is conveyed. However, here, the movement of the carriage 13 is shown relative to the sheet in order to make the main scanning operation on the sheet easier to understand.
First, in the inkjet recording apparatus, a user specifies a predetermined size of a sheet as a recording medium (step 61). Then, the user inputs the specified paper size information from the operation unit 503.
Then, the inkjet recording apparatus moves the carriage 13 to detect the width of the sheet 3 set in the inkjet recording apparatus (Step 62). The detection of the width of the sheet 3 is performed by the above-described method using the sheet detection sensor 109.
[0043]
Next, the inkjet recording apparatus compares the detected size of the width of the paper 3 detected by the paper detection sensor 109 with the specified size specified by the user, and calculates the difference between these sizes. Is larger than a predetermined value (for example, 5 mm) that is set in advance (step 63).
If this difference is larger than the predetermined value (Step 63; Y), the printing process in the ink jet recording apparatus is stopped and the process ends.
On the other hand, when the difference is smaller than the predetermined value (Step 63; N), the main scanning printing is executed while performing the mask processing based on the detected width of the sheet 3 (Step 64).
Then, it is confirmed that all the printing processes in the page have been completed (step 65), and the process is terminated.
[0044]
【The invention's effect】
According to the first aspect of the present invention, the size of the recording medium can be accurately and appropriately recognized by comparing the designated size with the actually measured size.
According to the second aspect of the present invention, when the difference between the designated size and the actually measured size is larger than a predetermined value, the size of the recording medium is detected again, Erroneous detection of the size of the recording medium can be suppressed.
According to the third aspect of the present invention, when the difference between the designated size and the actually measured size is larger than a predetermined value, the printing process is stopped, and the useless recording material is stopped. Consumption can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view of a mechanism of an ink jet recording apparatus according to an embodiment.
FIG. 2 is a side view of a mechanism of the ink jet recording apparatus according to the embodiment.
FIG. 3 is a front view of the ink jet printer.
FIG. 4 is a diagram illustrating a configuration of a sheet detection sensor.
FIG. 5 is a diagram illustrating a configuration of a sheet detection sensor.
FIG. 6 is a side view of the mechanism of the inkjet recording apparatus when the carriage moves in the main scanning positive direction from the capping position.
FIG. 7 is a side view of a mechanism of the ink jet recording apparatus when the carriage has moved to a right end detection position of a sheet.
FIG. 8 is a side view of the mechanism of the ink jet recording apparatus when the carriage has moved to the left end detection position of the sheet.
FIG. 9 is a block diagram illustrating a configuration of a control system of the inkjet recording apparatus according to the present embodiment.
FIG. 10 is a flowchart illustrating a procedure of a process of detecting an edge of a sheet.
FIG. 11 is a diagram illustrating a positional relationship between a sheet detection sensor and each nozzle row.
FIG. 12 is a flowchart illustrating a procedure of an image masking process.
FIG. 13 is a flowchart showing a procedure of an image masking process.
FIG. 14 is a diagram showing a circuit using a main scanning encoder signal.
FIG. 15 is a flowchart illustrating a procedure of an image forming process in the first embodiment.
FIG. 16 is a diagram illustrating a moving direction of a carriage in the first embodiment.
FIG. 17 is a flowchart illustrating a procedure of an image forming process in the second embodiment.
FIG. 18 is a diagram illustrating a moving direction of a carriage in the second embodiment.
[Explanation of symbols]
1 body
2 Printing mechanism
3 paper
4 Paper cassette
5 Bypass tray
6 Output tray
11 Main guide rod
12 Sub tank
13 Carriage
14 head
15 Ink cartridge
16 Ink supply tube
17 Main scanning motor
18 Drive pulley
19 driven pulley
20 Timing belt
21 Paper feed roller
22 friction pads
23 Guide member
24 transport rollers
25 Transport rollers
26 Tip roller
27 Sub-scanning motor
29 Electrostatic transport belt
30 Charger
33 Paper ejection roller
37 Maintenance and recovery mechanism
47 cover

Claims (3)

In an image forming apparatus that sprays a recording material from a nozzle provided on a head to form an image on a recording medium,
Receiving means for receiving an input of a designated size of a recording medium set in the image forming apparatus;
Detecting means for measuring the size of the recording medium set in the image forming apparatus and detecting the actually measured size,
Comparing means for comparing the designated size received by the receiving means with the actually measured size detected by the detecting means;
When the difference between the designated size and the measured size is smaller than a predetermined value as a result of the comparison by the comparing unit, an area where the print processing is not performed on the recording medium based on the measured size, and an area where the print processing is performed. Mask processing means for performing mask processing for setting
A print processing unit that performs a print process only on an area where the print process is performed, which is set by the mask processing unit,
An image forming apparatus comprising: When the difference between the designated size and the measured size is larger than a predetermined value as a result of the comparison by the comparing unit, the size of the recording medium set in the image forming apparatus is measured again to detect the measured size again. Re-detection means,
2. The image forming apparatus according to claim 1, wherein the comparing unit compares the designated size received by the receiving unit with the re-measured size detected by the re-detecting unit. 2. The image forming apparatus according to claim 1, wherein when the difference between the designated size and the measured size is larger than a predetermined value as a result of the comparison, the image forming process in the image forming apparatus is stopped. apparatus.

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