JP2006321593A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device such as an ink jet printer capable of eliminating the delay in the processing time to a printing job by reducing the number of execution of a control sequence as much as possible by using the stored print data of the previously used size. <P>SOLUTION: A cassette detection sensor detects whether or not a paper feed cassette is attached/detached to/from a printer body, and its detection signal is transmitted to a control unit. The control unit to receive the present print command transmitted from an upper rank device determines whether or not the paper feed cassette is attached/detached according to presence/absence of the detection signal from the cassette detection sensor between the time when information on the size of the previously used sheets is stored, and the time when the present print command is received. If the control unit determines that the paper feed cassette has ever been attached/detached, the unchanged use of information on the size of the previously used sheets stored in a memory unit is determined, and a series of control sequences starting from the detection of the size detection sensor are omitted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, and a printer that records an image on a sheet-like recording medium (hereinafter referred to as a sheet) such as plain paper.

  In recent years, an ink jet recording apparatus has been required to have the same beauty and quality as those of a silver halide photograph, and the printing of photographs has been actively performed. For this reason, not only the sheet quality but also the sheet size ranges from a standard size to a special size.

  Usually, for example, when a user selects a sheet size in a printer, the user performs an input operation based on software (an application or a printer driver) of a host device such as a host computer or a personal computer connected to the printer. . Recently, versatile applications such as taking an image from a digital camera and printing it, or inserting a memory card or combining it with a scanner for printing are rapidly progressing. Even in such a case, an input for selecting the sheet size is performed, and the user needs to replenish or load a sheet of the selected size, which is the same as when connected to a host device.

  By the way, the operation of inputting the sheet size is troublesome especially for an unaccustomed user and easily causes an input error due to a mistake. To prevent this, it is effective to automatically detect the size of the sheet loaded by the user with a sensor, and many such automatic sheet size detection devices and methods have been proposed and put to practical use in the fields of printers and copiers. (See, for example, Patent Documents 1, 2, and 3). These patent documents disclose that a sheet size is detected by a sheet feeding tray or the like on which sheets are stacked and stored, and the detected result is displayed on a display unit or the like to notify the user.

  However, if the judgment and control are performed by detecting sheets of a very wide variety of sizes as in the current trend, the cost of the components constituting the detection system and the control system is increased, and particularly low for general consumers. It is not realistic to install it in the price model. Further, even if the model is capable of stacking and storing several types of sheets together, it is a real problem to install a detection unit for each size, which is very expensive.

  Therefore, the following way of thinking is effective in order to achieve both the user's convenience and at the same time satisfy both of the problems of suppressing the cost increase.

  A sheet fed from a sheet feeding unit such as a sheet feeding tray is moved along with a reflective optical sensor to a recording head of an image forming unit that moves in a sub-scanning direction in a direction orthogonal to the sheet conveying direction. Detect the width (horizontal dimension). That is, for a standard size sheet, the sheet length (vertical dimension) is determined by detecting the sheet width, and the sheet size is determined. In this case, since the sheet size can be automatically identified simply by providing an optical sensor for detecting the sheet width, the cost can be reduced, and mounting on a low-priced model can be expected. However, while these advantages can be obtained, there is a new problem that a control sequence for detecting the sheet width and identifying the size must be executed each time.

JP-A-62-027251 Japanese Patent Laid-Open No. 01-133732 Japanese Patent Laid-Open No. 11-157700

  Since the control sequence is executed every time the sheet width is detected in this way, the processing speed for one print job is reduced by the estimated sequence execution time, that is, it takes a long time to complete printing. If the problem such as the delay of the printing time can be eliminated, it is effective because it is possible to achieve both user convenience and cost.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to make it easy for a user to identify various sizes of sheets that are recording media at low cost, and to make it convenient for the user. It is an object of the present invention to provide an image forming apparatus that can eliminate a delay in processing time for a print job by reducing the number of executions of a control sequence as much as possible.

  The image forming apparatus according to the present invention includes a sheet size detecting unit that detects a size of a sheet as a recording medium, a storage unit that stores and stores size information of a previously used sheet, and a storage unit that stores the sheet includes an image. A storage unit detection unit that detects attachment / detachment that is attached to or removed from the forming apparatus main body, and the storage unit detection unit from the time point when the size information of the previously used sheet is stored in the storage unit to the present. Control means for omitting a series of control sequences starting from the detection of the sheet size detection means by using the size information of the last used sheet when it is determined that the storage unit is not mounted based on the detection result. It is characterized by becoming.

  According to the image forming apparatus of the present invention, various sizes of sheets as recording media can be automatically and easily identified at a low cost, and the burden can be reduced without forcing an inexperienced user to perform a sheet size selection operation. In addition, when the size information of the previous sheet is available, the control sequence every time starting from the detection of the sheet size is omitted, so that the processing time of the print job is not delayed, so that it is expected to improve the printing capability. . Moreover, there is an advantage that mounting on a low-priced model can be realized by suppressing the cost increase.

  Hereinafter, an ink jet recording apparatus as an embodiment of an image forming apparatus according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIGS. 1A to 1C show the entirety of an ink jet recording apparatus main body 1 according to the present embodiment. A sheet 3 which is a recording medium stacked and stored in a sheet feeding cassette 2 is one sheet by a feeding apparatus. The paper is separated and sent to the recording unit. After printing is completed by image formation, the paper is discharged onto the paper discharge tray 4.

  As shown in FIGS. 2A and 2B, the sheet 3 is conveyed in the direction of the arrow (in the order of numbers 5, 6 and 7) in the apparatus main body. That is, the sheets 3 stacked and stored in the paper feed cassette 2 are separated one by one by the feeding device 8 and fed in the direction of the arrow (number 5), and U-turns in the direction of the arrow 6 to the recording unit 9. It is sent. A paper sensor (not shown) for detecting the quality type of the sheet 3 is disposed in the middle of the paper passing path (conveyance path) to optically detect the surface state of the sheet recording surface, and the sheet is detected based on the detection signal. 3 types such as paper quality can be identified. The sheet 3 is recorded by the recording unit 9 under the ink discharge conditions adapted to the identified sheet type, and is discharged in the direction of the arrow 7 after recording. The recording unit 9 includes a carrier 10 that is a moving body for performing scanning while reciprocating in a direction perpendicular to the surface of the sheet 3, and is a recording head that is carried by the carrier 10 and moves integrally in the scanning direction. Reference numeral 11 denotes an image formed by ejecting ink onto a sheet 3 from a nozzle (not shown) to perform recording. Further, a size detection sensor 12 as a reflection type optical detection means is mounted on the carrier 10, and light is projected onto the sheet 3 from the opposite direction, and the end face of the sheet 3 is detected based on the level of the reflected light. FIG. 3 is an enlarged view showing a portion where the size detection sensor 12 is provided.

  That is, the size detection sensor 12 scans the carrier 10 while monitoring the reflected light level at the leading edge of the sheet 3 picked up by the feeding device 8, and from the difference in the reflected light level between the platen 14 and the sheet 3. The position of the edge 13 of the sheet 3 is detected (see FIG. 3). By detecting the opposite sheet edge position in the same manner, the width dimension of the sheet 3 is measured. However, in a normal printer, in many cases, the opposite side of the sheet edge is a sheet 3 of any size, and one side abuts against a fixed wall to be a reference position. In this case, since the position on the reference side is constant, detection is not necessary, and it is sufficient to recognize the sheet width dimension only by detecting the position of the edge 13 that is one side facing the reference side. The fixed-size sheet 3 that is frequently used has a combination of a width dimension (horizontal) and a length dimension (vertical). Therefore, if one of the vertical and horizontal dimensions can be identified, the sheet size can be specified. . In the present embodiment, the case where the sheet size is specified from the sheet width dimension is described.

  Note that after the sheet 3 is picked up and fed out, the length dimension of the sheet 3 can be measured by relating it to the sheet feed amount by a sensor provided in the conveyance path, and the sheet length (vertical dimension). From the above, the sheet size can be specified. Of course, it is possible to configure the sheet size more accurately by measuring both the width and the length.

  Next, as shown in FIGS. 4A to 4C, a large plate size sheet 15 and a small plate size sheet 16 can be stored together in the sheet feeding cassette 2. For example, A4 size plain paper is stored in the cassette main body 17 and L size photographic paper is stored in the small cassette 18, and A4 size plain paper is used when a web print instruction is issued according to the contents to be printed. Alternatively, when a snap photo print instruction is issued, L-size photographic paper can be automatically switched and fed. As shown in FIG. 4 (c), the advancing / retreating drive gear 19 meshes with a rack gear 20 formed integrally with the small cassette 18, and is transmitted from a drive gear train (not shown). The driving force is received by the advancing / retreating drive gear 19 and converted into a reciprocating linear motion in the direction of the arrow 21. The position of the small cassette 18 is controlled by this reciprocating mechanism. When the small cassette 18 is in the state shown in FIG. 4A, the sheet 15 is fed out one by one by the feeding device 8, and in the state shown in FIG. 4B. The sheet 16 is fed out one by one by the feeding device 8.

  The types of sheets that can be stored are examples of the above combinations and are not limited to this. There are noun sizes, L sizes, postcards, 4 inch x 6 inch sizes in small cassettes, and 2 L in large cassettes. A sheet having a size of ~ A4 can also be stored.

  FIG. 5 shows a structure of a portion provided with detection means for detecting whether or not the paper feed cassette 2 is mounted. A convex portion 23 (see FIG. 1) is formed in front of the cassette, and a cassette detection sensor (storage portion attachment / detachment detecting means) 22 is attached to a portion corresponding to the convex portion 23 when the cassette is attached to the printer body 1. When the paper feed cassette 2 is inserted into the printer body 1 and set, the cassette detection sensor 22 detects the convex portion 23 of the paper feed cassette 2 to determine whether the cassette is attached. Cassette removal can also be detected and recognized by the detection signal from the cassette detection sensor 22.

  FIG. 6 is a functional block diagram showing a control system of the printer body 1. In this case, the host computer 400 is connected to the host computer 400, receives a command signal from the host computer 400, data based on character information or image information to be recorded (hereinafter referred to as image data), and an image based on the image data. Record. Further, the printer main body 1 returns data for confirming whether or not the data is correctly transferred, current data for notifying the operation state of the printer main body 1 and the like to the host computer 400. The image data is not limited to transmission from the host computer 400, and can be captured from another digital camera 412 or memory card 413 directly connected thereto. In addition, it is possible to transmit / receive to / from all of these external devices at the same time, or to / from any one of them, and connection by wireless means is also possible.

  Image data received from the host computer 400, digital camera 412, memory card 413, and the like is input to the reception buffer 401 of the printer main body 1. The printer main body 1 includes a control unit 402 mainly composed of a CPU (Central Processing Unit) 402 a that controls the recording operation in an integrated manner based on data input to the reception buffer 401. The control unit 402 performs processing on the image data input to the reception buffer 401, decompresses the compressed image data, detects boundaries and blanks between the colors, and generates data for recording. 402b. The control unit 402 is connected to a memory unit 403 including a RAM that temporarily stores received image data and the like, and a control unit of each unit.

  A mechanical control unit 404 controls driving of a mechanical unit 405 such as a carrier motor, an LF motor, a paper feed motor, and a small cassette drive motor. The sensor / SW control unit 406 processes signals from the various sensors including the size detection sensor 12 and the paper type sensor and the SW (switch) unit 407. The display element control unit 408 controls the display element unit 409 including LEDs and liquid crystal display elements of the display panel group. The recording head control unit 410 controls the recording head 411. Each of these control units operates based on a command from the control unit 402, and sends a feedback signal or the like to the control unit 402 as necessary. For example, the recording head control unit 410 sends temperature information indicating the state of the recording head 411 to the control unit 402.

  Sheet information based on detection signals from the size detection sensor 12 and the paper type sensor is processed in the printer main body 1 to determine the size and surface state of the sheet 3, and based on the result, an optimum recording method is selected and executed. However, it is also possible to transmit the size information such as the size and surface state of the sheet 3 to the host computer 400, and determine the processing inside the driver software in the host computer 400 to transmit optimum image data. .

  Next, the operation of the apparatus having the above configuration will be described with reference to the flowchart of FIG.

  In step S1, paper feeding is started. When the sheet size information is a large plate size (2L size or more such as A4 size), the state shown in FIG. 4A is shown. In the case of a small plate size (business card size such as L size size to 4 inches × 6 inches size) The operation is automatically switched to the state shown in FIG. In this automatic switching operation, it is also possible for the user to store in the storage means in the printer body 1 in advance the setting that A4 is loaded into the large plate sheet cassette and L size is loaded into the small plate sheet cassette. . If the setting and the sheet command to be printed this time do not match, it is possible to cancel printing, but it is possible that the user has forgotten to make a setting or has made a mistake, so the configuration proceeds to the next flow. Is desirable.

  The cassette detection sensor 22 detects that the paper feed cassette 2 has been attached to and detached from the printer main body 1. That is, the cassette detection sensor 22 detects whether the paper feed cassette 2 is attached or removed from the attached state. The detection signal is transmitted to the control unit 402.

  In step S <b> 2, when the current print command transmitted from the host apparatus such as the host computer 400 is received by the reception buffer 401, the control unit 402 starts from the time when the size information of the last used sheet is stored in the memory unit 403. Judgment is made based on the data indicating that the paper feed cassette 2 has been attached / detached, that is, whether or not there is a detection signal from the cassette detection sensor 22 until the present time when the print command is received.

  When it is determined that there is a fact that the paper cassette 2 has been attached / detached up to now (Yes), the control unit 402 proceeds to step S3 to reset the size information of the last used sheet, and is stored in the paper cassette 2. The current storage sheet size is identified based on the detection signal from the size detection sensor 12 that detects the sheet width of the sheet 3, and the measured value is acquired. That is, the control sequence based on the detection signal from the size detection sensor 12 is executed only when there is a fact that the paper feed cassette 2 is attached or detached.

  On the other hand, if the control unit 402 determines that the sheet cassette 2 has not been attached / removed so far in step S2 and there is no such fact (No), the sheet of the last used sheet stored in the memory unit 403 is determined. It is determined that the size information is used as it is, and a series of control sequences starting from detection by the size detection sensor 12 is omitted (step: S4).

  Next, in step S5, the control unit 402 determines the size information of the last used sheet decided to be used this time, that is, the size of the currently stored sheet stored in the sheet feeding cassette 2, and the host computer 400 or the like. It is determined whether or not the received print command matches the sheet size based on the print data. If it is determined that they do not match (No), the process proceeds to step S6, and an alert (notification) is sent to inform the user that the sheet size of the print instruction is different from the size of the currently stored sheet in the paper feed cassette 2. ) Is displayed on a monitor screen such as a liquid crystal display (LCD), and printing is not executed. If it is determined in step S5 that the sizes of both the print data and the current storage sheet match (Yes), the control unit 402 proceeds to step S7 and executes printing, assuming that there is no problem, and a series of processes. Finish.

(Second Embodiment)
For the second embodiment, referring to the operation flowchart of FIG. 8, only the differences between the two will be described in correspondence with the operation flowchart of FIG. 7 shown in the first embodiment.

  In step S11, when the power switch for starting up and starting up the printer body 1 is turned on, the size data value stored in the memory unit 403 as the size information of the previously used sheet is cleared (step: S12). This is because the monitoring based on the detection by the cassette detection switch 12 cannot be performed during the period when the power switch is turned off, so that the user may have inserted and removed the sheet cassette 2 and replaced the sheet 3. Yes, this is a flow that is executed only when the power switch is turned on by performing the process of deleting the stored value of the size information of the last used sheet.

  Accordingly, when paper feeding is started (step: S13), it is determined whether or not a stored value of the size information of the last used sheet exists (step: S14), and it is determined that there is no size information stored value. (No), since it is the first time after the power switch is turned on, the process proceeds to step S20, and a new sheet size is measured by identifying the size based on the detection signal from the size detection sensor 12. When it is confirmed that the size storage value exists and is stored in the memory unit 403 (Yes), the process proceeds to step S15, and whether or not there is a fact that the sheet cassette 2 has been attached / detached up to now is attached / detached. Judgment is made. When the fact of cassette attachment / detachment is recognized (Yes), the process proceeds to step S20, where the size is identified by the detection signal from the size detection sensor 12, and the size is measured. If it is determined that the cassette is not attached or detached (No), the process proceeds to step S16, and the size value based on the size information of the previously used sheet is used as it is. In step S17, it is determined whether or not the print data sent as a print command this time from the host apparatus matches the size of the current stored sheet in the paper feed cassette 2. If they do not match (No), the process proceeds to step S18, where an alert is generated to notify the user that the sheet size is different, and printing is not performed. If they match (Yes), there is no problem, so the process proceeds to step S19, the required printing is executed, and the series of processes is completed.

(Third embodiment)
As shown in FIGS. 9A and 9B, in the third embodiment, a feeding device 28 is disposed on the upper portion of the printer main body 1, and an opening / closing lid 24 is provided on the upper portion thereof so as to be freely opened and closed. FIG. The sheets 3 are stacked and stored below the opening / closing lid 24, and after loading, the opening / closing lid 24 is closed to perform printing. When the sheet 3 is handled, the opening / closing lid 24 is opened, replenished or replaced, and then closed again to complete the operation. An open / close detection sensor (not shown) is attached to the open / close lid 24 so that the open / close state of the open / close lid 24 can be recognized. In this embodiment, the detection signal of the open / close detection sensor is replaced with the detection signal of the cassette detection sensor 12 in the first embodiment, and the rest is configured in the same manner as in the first embodiment. can do. As a result, the size detection operation can be executed only when the sheet 3 is replaced as in the first embodiment.

(Fourth embodiment)
FIG. 10 shows a fourth embodiment. In this case, it is a configuration example in which several stages of cassettes are stacked below the printer main body 29, and a two-stage structure including an upper cassette 26 and a lower cassette 27 is shown. The cassette detection sensor 12 shown in the first embodiment is attached to the upper and lower cassettes 26 and 27 to detect whether the cassette is attached or detached. Other configurations are the same as those in the first embodiment, and a system that uses the detection result can be configured. Thus, the same effects as those in the first embodiment can be obtained.

  As understood from the above, in the inkjet printer of each embodiment, when it is determined that the size information of the sheet used last time can be used, by omitting the control sequence starting with the size measurement by the current sheet size detection, As in the prior art, it is possible to solve the problem that the printing time is delayed by repeating the control sequence every time the sheet size is measured. That is, by reducing the control sequence as much as possible, the processing time in one print job, that is, the time until the end of printing can be shortened. As a result, it is possible to provide a printer system capable of realizing a practical automatic recording sheet size detection function at a low cost and at the same time preventing a decrease in printing speed.

  Although several examples of the embodiments have been described, the present invention is not limited to these embodiments, and other embodiments, application examples, and modifications are within the scope not departing from the gist of the present invention. Combinations of these are also possible.

FIGS. 4A to 4C are diagrams illustrating how a sheet feeding cassette is attached and detached in an inkjet printer which is an example of an image forming apparatus equipped with a sheet feeding apparatus according to an embodiment of the present invention. FIGS. 4A and 4B are sectional views showing the internal mechanism of the printer main body. FIG. 3 is an enlarged perspective view of a main part of the printer body internal mechanism according to the embodiment. (A)-(c) is a cassette figure which shows the state which accommodated the sheet | seat of the large and small size size simultaneously in the paper feeding cassette, and its internal mechanism figure. The figure which shows a cassette mounting | wearing detection means. FIG. 3 is a functional block diagram illustrating a control system structure of the ink jet printer according to the embodiment. The flowchart which shows operation | movement of 1st Embodiment. The flowchart which shows operation | movement of 2nd Embodiment. The perspective view which shows the structure of 3rd Embodiment. The figure which shows the structure of 4th Embodiment.

Explanation of symbols

1 Printer body 2 Paper feed cassette 3 Sheet (recording medium)
8 Feeding device 9 Recording unit 11 Recording head 12 Size detection sensor (sheet size detection means)
13 Sheet edge 15 Large plate sheet 16 Small plate sheet 17 Cassette body portion 18 Small cassette 19 Advance / retreat drive gear 20 Rack gear 22 Cassette detection sensor (storage portion detection means)
23 Convex 24 Open / close lid 25 Open / close detection sensor 26 Upper cassette 27 Lower cassette

Claims (7)

Sheet size detecting means for detecting the size of a sheet as a recording medium;
Storage means for storing and storing size information of the last used sheet;
A storage unit detecting means for detecting whether the storage unit storing the sheet is attached to or detached from the main body of the image forming apparatus;
If it is determined that the storage unit is not mounted based on the detection result from the storage unit detection unit between the time when the size information of the previous use sheet is stored in the storage unit and the present time, Control means for omitting a series of control sequences starting with detection of the sheet size detection means by utilizing the size information of
An image forming apparatus comprising: Sheet size detecting means for detecting the size of a sheet as a recording medium;
Storage means for storing and storing size information of the last used sheet;
An open / close lid detecting means for detecting whether the open / close lid provided in the storage portion for storing the seat is opened or closed;
If it is determined that the opening / closing lid has not been opened / closed based on the detection result from the opening / closing lid detecting means between the time point and the present time after storing the size information of the previously used sheet in the storage means, Control means for omitting a series of control sequences starting with detection of the sheet size detection means by utilizing sheet size information;
An image forming apparatus comprising: 3. The image forming apparatus according to claim 1, wherein the sheet size detection unit optically detects any one of vertical and horizontal sides of the sheet in a conveyance path on a downstream side of the storage unit. The sheet size detecting means optically detects one edge of the sheet width direction as the carrier carrying the recording head of the image forming apparatus main body moves in the sub-scanning direction. The image forming apparatus described. 5. The image forming apparatus according to claim 1, wherein the image forming apparatus includes a plurality of storage units, and each includes a unit that stores a size of a sheet stacked in each storage unit. The size information of the last used sheet is cleared when a period during which a detection result by the storage unit detection unit or the opening / closing lid detection unit is invalid is provided. The image forming apparatus described in the item. The image forming apparatus according to claim 6, wherein the detection result invalid period is a power-off period of the image forming apparatus main body.

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