Image forming apparatus

Abstract

To perform image formation related to image formation processing in which interruption occurs again, even if capacity of a storage section is insufficient.SOLUTION: Image data from an external device 120 is transferred to a host region 21a. The image data stored in the host region 21a is transferred to a raster processing region 21c and is transferred from the raster processing region 21c to an image formation operation region 21d. An image formation operation is performed on the basis of raster data R3 stored in the image formation operation region 21d. When the image data is transferred to the raster processing region 21c, the same data is also transferred to an external storage device 110. The data stored in the external storage device 110 is used in recovery processing after processing interruption.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an image forming apparatus.

Background Art

[0002] Conventionally, in an image forming apparatus having an image forming unit that forms an image on a print medium, the image forming process may be interrupted due to a jam or the like. In such a case, in the image forming apparatus of Patent Document 1, as a jam recovery function, the image forming unit is caused to perform the image forming related to the interrupted image forming process again.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The jam recovery function of Patent Document 1 is invalidated when the capacity of the storage unit (memory) used for image formation is insufficient. From the viewpoint of improving user-friendliness, it is required to be able to perform the image formation related to the interrupted image forming process again even when the capacity of the storage unit is insufficient.

[0005] An object of the present invention is to provide an image forming apparatus capable of performing the image formation related to the interrupted image forming process again even when the capacity of the storage unit is insufficient.

Means for Solving the Problems

[0006] The image forming apparatus of the present invention includes an image forming unit that forms an image on a print medium, a connection unit that can be connected to an external storage medium, a storage unit, and a control unit. The control unit performs a first storage process of storing the image data received from an external device or the data after its analysis in each of the storage unit and the external storage medium connected to the connection unit, an image forming process of causing the image forming unit to perform the image forming based on the data stored in the storage unit, and when an interruption of the image forming process occurs, based at least on the external data at the time of interruption, which is the data stored in the external storage medium at the time of the interruption, the image forming unit is caused to perform again the image forming related to the image forming process in which the interruption has occurred on a print medium different from the print medium on which the image forming was being performed at the time of the interruption (re-image forming process).

Effect of the Invention

[0007] By the first storage process, the image data or the data after its analysis is stored not only in the storage unit but also in the external storage medium. Therefore, when an interruption of the image forming process occurs, even if the capacity of the storage unit is insufficient for executing the re-image forming process, the re-image forming process can be performed based on the data stored in the external storage medium.

Brief Description of the Drawings

[0008]

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Embodiment for Carrying Out the Invention

[0009] A printer 1 (corresponding to the "image forming apparatus" of the present invention) according to a preferred embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the printer 1 has an image forming unit 10, a storage device connection unit 15, a touch panel display 16, and a control unit 20. The image forming unit 10 accommodates a plurality of types of paper. Examples of the types of paper include glossy paper, inkjet paper, plain paper, and the like. The image forming unit 10 executes an image forming operation of forming an image on the paper by attaching ink to any type of paper.

[0010] The storage device connection unit 15 is an interface unit capable of connecting an external storage device 110 (corresponding to the "external storage medium" of the present invention). The storage device connection unit 15 may support either a wired or wireless connection method. As an example, an interface unit using the USB (Universal Serial Bus) method may be used. In this case, the external storage device 110 may be a USB memory.

[0011] The touch panel display 16 (corresponding to the "notification unit" of the present invention) displays characters, images, and the like on the screen. Further, when a finger or the like touches the screen, the touch panel display 16 detects the contact position and outputs the detection result to the control unit 20. Thereby, the touch panel display 16 can receive various user inputs.

[0012] As shown in FIG. 1, the control unit 20 includes hardware such as a CPU (Central Processing Unit) 20a, a ROM (Read Only Memory) 20b, a RAM (Random Access Memory) 20c, and an ASIC (Application Specific Integrated Circuit).

[0013] The ROM 20b is composed of a non-volatile memory and is used as a storage unit for long-term data storage. The ROM 20b stores mainly program data and the like executed by the CPU 20a and the ASIC.

[0014] The RAM 20c is composed of a volatile memory and functions as a temporary working storage unit 21 shown in FIG. 2. In the storage unit 21, storage areas for storing the above program data, storage areas for storing image data indicating images to be formed on sheets, and storage areas for storing other temporary data for work are secured. Program data is transferred from the ROM 20b to the storage area for programs. As shown in FIG. 2, the storage area for image data is divided into a host area 21a, an intermediate buffer area 21b, a raster processing area 21c, and an image forming operation area 21d. Details of these storage areas will be described later. The size counter 21X and the notification mode flag 21Y, which will be described later, are stored in the other working storage areas.

[0015] The hardware including the CPU 20a that constitutes the control unit 20 executes various processes based on the program data in the storage unit 21. As a result, various functional units that execute various processes are constructed within the control unit 20 as shown in FIG. 2. For example, as functional units based on the program for image forming processing transferred to the storage unit 21, a host control unit 22, a raster processing unit 23, and an image forming operation control unit 24 are constructed. The host control unit 22, the raster processing unit 23, and the image forming operation control unit 24 cooperate with each other to execute image forming processing. The image forming processing is a process of controlling the image forming unit 10 to perform an image forming operation on a sheet based on image data acquired from an external device 120 such as a PC.

[0016] The image data has, in addition to data related to image formation for one page or a plurality of pages, data representing the image quality used for image formation and the type of sheet. The data representing the image quality indicates whether it is high image quality or low image quality. The data representing the type of sheet indicates whether it is glossy paper, inkjet paper, or plain paper.

[0017] The image data of this embodiment includes raster image data and vector image data. The raster image data is data including pixel values of each pixel constituting the image. The vector image data is data described in PDL (page description language). The vector image data includes data representing a plurality of commands for instructing the content of image formation.

[0018] Each functional unit of the control unit 20 processes the image data as shown in FIGS. 3 and 4.

[0019] The processing of the raster image data is performed as shown in FIG. 3. The host control unit 22 acquires the raster image data IM1 from the external device 120 and transfers it to the free area of the host area 21a of the storage unit 21. The raster processing unit 23 transfers the raster data R1 included in the raster image data IM1 from the host area 21a to the free area of the raster processing area 21c (corresponding to the "first storage process" of the present invention). The image formation operation control unit 24 transfers a part of the raster data R1 stored in the raster processing area 21c to the free area of the image formation operation area 21d. The image formation operation control unit 24 controls the image forming unit 10 to perform an image forming operation based on the raster data R3 stored in the image formation operation area 21d.

[0020] The above-mentioned free area used as the data transfer destination is secured by sequentially releasing the areas related to the processed data. For example, the free area of the host area 21a is secured by quickly releasing the storage area related to the data that has been transferred to the raster processing area by the raster processing unit 23 after the transfer. Also, the free area of the raster processing area 21c is secured by quickly releasing the storage area related to the data that has been transferred to the image formation operation area by the image formation operation control unit 24 after the transfer. Further, the free area of the image formation operation area 21d is secured by quickly releasing the storage area related to the data that has been used for the image formation operation by the image formation operation control unit 24 after the transfer.

[0021] The processing of the vector image data IM2 is performed as shown in FIG. 4. The host control unit 22 acquires the vector image data IM2 from the external device 120 and transfers it to the free area of the host area 21a of the storage unit 21. The raster processing unit 23 sequentially performs analysis processing on the vector image data IM2 in the host area 21a from the head data, and accumulates the analyzed data M thus obtained in the intermediate buffer area 21b. The analysis processing is performed by decoding the image formation content indicated by each command included in the vector image data IM2 and sequentially generating raster data according to the content. When a predetermined amount (for example, one page) of analyzed data M is accumulated in the intermediate buffer area 21b, the raster processing unit 23 transfers the predetermined amount of analyzed data M to the free area of the raster processing area 21c (corresponding to the "first storage process" of the present invention). The image formation operation control unit 24 transfers a part of the raster data R1 stored in the raster processing area 21c to the free area of the image formation operation area 21d. The image formation operation control unit 24 controls the image forming unit 10 to perform an image forming operation based on the raster data R3 stored in the image forming operation area 21d.

[0022] In the transfer process of the vector image data, the method for securing free areas in each of the host area 21a, the raster processing area 21c, and the image formation operation area 21d is the same as the above-described method related to the transfer process of the raster image data. Regarding the intermediate buffer area 21b, the entire area is released when a predetermined amount of analyzed data M is transferred to the raster processing area 21c.

[0023] By the way, for example, when the image formation process is interrupted for various reasons such as a jam (paper jam) occurring in the image forming unit 10, a recovery process (corresponding to the "re-image formation process" of the present invention) for performing the image formation process again may be performed.

[0024] On the other hand, in the image forming process, as described above, in order to secure free space in each storage area, the areas related to the processed data are sequentially released. Such securing of free space is necessary when the size of the entire image data is larger than the storage capacity of the storage unit 21 (that is, the RAM 20c), that is, when the storage capacity of the storage unit 21 is insufficient for the image data. Since the necessary raster data is sequentially stored in the sequentially released storage areas, the raster data for all pages is not stored in each storage area, but only the raster data for some pages is stored, or only a part of the data for one page is stored.

[0025] Even if a recovery process is attempted in such a situation, there is a possibility that the data necessary for the process remains in the storage unit 21. Therefore, there is a possibility that the image forming process cannot be re-executed only by using the data in the storage unit 21. In particular, when the storage capacity of the storage unit 21 is originally small, the possibility that the necessary data remains is low, and the possibility that the image forming process cannot be re-executed is high.

[0026] Therefore, in the present embodiment, as shown in FIGS. 3 and 4, while the raster processing unit 23 transfers the raster image data IM1 in the host area or the analyzed data M in the intermediate buffer area 21b to the raster processing area 21c, data having the same content is also transferred to the external storage device 110 connected to the storage device connection unit 15 (corresponding to the "first storage process" of the present invention). As a result, the raster data R2 stored in the external storage device 110 is sequentially accumulated from the data corresponding to the head of the first page. The raster processing unit 23 performs this transfer process while counting the data sizes transferred to the raster processing area 21c and the external storage device 110. The value indicating the result of the count is stored in the storage unit 21 as a size counter 21X (see FIG. 2).

[0027] In the external storage device 110, the areas related to the processed data are not released in order to secure free space. Therefore, when the image forming process is interrupted, the data from the data corresponding to the head of the first page to the most recently transferred data remains.

[0028] In the recovery process, from the data at the head of the first page stored in the external storage device 110 to the data most recently transferred, the interrupted image forming process is restarted from the beginning using this data.

[0029] Hereinafter, an example of the flow of data transfer by the image forming process will be described with reference to FIGS. 5 to 13. First, the case where the size of the raster data per page is relatively small will be described.

[0030] At the time of image formation, as shown in FIG. 5, the raster data R1 transferred from the host area 21a or the intermediate buffer area 21b to the raster processing area 21c includes data for a plurality of pages. The raster data R2 transferred from the host area 21a or the intermediate buffer area 21b to the external storage device 110 includes data from the head to the most recent of the first page. The raster data R3 stored in the image forming operation area 21d is a part of the raster data R1 transferred from the raster processing area 21c. In FIG. 5, as an example, a state is shown in which both the raster data R1 and R2 are composed of the data of the first and second pages, and the raster data R3 is composed of the data of the first page.

[0031] At the time of interruption, as shown in FIG. 6, in the raster processing area 21c, there is raster data R1 (corresponding to the "internal data at the time of interruption" of the present invention) consisting of the data on the second and third pages, and in the external storage device 110, there is raster data R2 (corresponding to the "external data at the time of interruption" of the present invention) consisting of the data on the first to third pages. Also, in the image forming operation area, there is raster data R3 consisting of the data on the first page. This indicates that the image formation of the first page was being performed at the time of interruption. When the original data acquired from the external device 120 is raster image data, there is raster image data IM1 including the data on the fourth page in the host area 21a. When the original data acquired from the external device 120 is vector image data, there is analyzed data M consisting of the data on the fourth page in the intermediate buffer area 21b. The data on the fourth page is the data of the page consecutive to the third page, which is the last page remaining in the external storage device 110.

[0032] Thus, the situation of the raster processing area 21c at the time of interruption is as follows. (A) The data on the first page, which is the page on which image formation was being performed at the time of interruption (hereinafter referred to as the "interrupted page"), does not remain in the raster processing area 21c. (B) The data on the second to third pages consecutive to the interrupted page remains in the raster processing area 21c.

[0033] At the time of recovery processing, the following processing is performed according to the situations (A) and (B) above. First, as shown in FIG. 7, the data on the first page is transferred from the external storage device 110 to the raster processing area 21c. At this time, the data on the first page is overwritten in the area where the data on the third page was stored in the raster processing area 21c. This is to avoid overwriting the area of the second page, which is the page next to the interrupted page, the first page, in order to ensure the image forming operation based on the data on the second page. Then, the data on the first page is transferred from the raster processing area 21c to the image forming operation area 21d, and the image forming operation based on this is performed (corresponding to the "first image formation" of the present invention).

[0034] Next, as shown in FIG. 8, the data of the second page is transferred from the raster processing area 21c to the image forming operation area 21d, and an image forming operation based on this is performed.

[0035] Next, as shown in FIG. 9, the data of the third page is transferred from the external storage device 110 to the raster processing area 21c. Then, the data of the third page is transferred from the raster processing area 21c to the image forming operation area 21d, and an image forming operation based on this is performed.

[0036] For the fourth page and subsequent pages, the process shown in FIG. 10, which is the same as the normal process shown in FIG. 3 or FIG. 4, is performed. The data of the fourth page is transferred from the host area 21a or the intermediate buffer area 21b to the raster processing area 21c and the external storage device 110. Then, the data of the fourth page is transferred from the raster processing area 21c to the image forming operation area 21d, and an image forming operation based on this is performed. The same applies when there are subsequent pages from the fifth page onwards.

[0037] Next, an example of the data transfer flow in the image forming process will be described for the case where the size of the raster data per page is relatively large.

[0038] At the time of image formation, as shown in FIG. 11, the raster data R1 transferred from the host area 21a or the intermediate buffer area 21b to the raster processing area 21c includes the data up to the middle of the first page. The raster data R2 transferred from the host area 21a or the intermediate buffer area 21b to the external storage device 110 includes the data from the beginning to the most recent of the first page. The raster data R3 stored in the image forming operation area 21d is a part of the raster data R1 transferred from the raster processing area 21c. In FIG. 11, as an example, a state is shown in which both the raster data R1 and R2 consist of the data from the beginning to the middle of the first page, and the raster data R3 consists of the data in the middle of the first page.

[0039] At the time of interruption, as shown in FIG. 12, in the raster processing area 21c, there is raster data R1 (corresponding to the "internal data at the time of interruption" of the present invention) consisting of data from a certain position in the middle of the first page to a certain position, and in the external storage device 110, there is raster data R2 (corresponding to the "external data at the time of interruption" of the present invention) consisting of data from the beginning of the first page to a certain position. Also, in the image formation operation area, there is raster data R3 consisting of data in the middle of the first page. This indicates that the image formation of the first page was being performed at the time of interruption. When the original data acquired from the external device 120 is raster image data, there is raster image data IM1 including the data of the first page in the host area 21a. When the original data acquired from the external device 120 is vector image data, there is analyzed data M consisting of the data of the first page in the intermediate buffer area 21b.

[0040] Thus, the situation of the raster processing area 21c at the time of interruption is as follows. (C) What remains in the raster processing area 21c is data corresponding to after the middle of the first page, which is the interrupted page.

[0041] At the time of recovery processing, according to the situation in (C) above, the following processing is performed. First, as shown in FIG. 13, the data from the beginning of the first page to the position at the time of interruption is sequentially transferred from the external storage device 110 to the raster processing area 21c. Here, the raster processing unit 23 grasps, based on the size counter 21X (see FIG. 2) stored in the storage unit 21, which data was the last data stored in the external storage device 110 in the raster data R2, that is, which data corresponds to the position at the time of interruption. Based on this grasping, the data from the beginning of the first page to the position at the time of interruption is appropriately transferred from the external storage device 110 to the raster processing area 21c. Then, the data of the first page is sequentially transferred from the raster processing area 21c to the image formation operation area 21d, and the image formation operation based on this is performed.

[0042] For the part after the position at the time of interruption on the first page, the process of FIG. 14, which is the same as the normal process shown in FIG. 3 or FIG. 4, is performed. Data after the position at the time of interruption on the first page is transferred from the host area 21a or the intermediate buffer area 21b to the raster processing area 21c and the external storage device 110. Then, the data of the first page is sequentially transferred from the raster processing area 21c to the image forming operation area 21d, and the image forming operation based on this is performed. The same applies when there are subsequent pages.

[0043] Hereinafter, the notification process for prompting the user to connect the external storage device 110 will be described with reference to FIG. 15. Since it is a prerequisite for the above recovery process that the external storage device 110 is connected, this is a process for notifying the user to prompt this as necessary. The notification process is executed prior to the image forming process each time a request for the image forming process occurs.

[0044] First, the control unit 20 determines whether the notification mode is on or off (S1). Whether the notification mode is on or off indicates whether to perform the above notification. The user can set in advance whether the notification mode is on / off through user input on the touch panel display 16. The content is stored in the storage unit 21 as a notification mode flag 21Y (see FIG. 2). Therefore, the control unit 20 determines whether the notification mode is on / off by referring to the notification mode flag 21Y of the storage unit 21.

[0045] When it is determined that the notification mode is off (S1, No), the control unit 20 does not perform the notification in S5 and executes the image forming process (S6). When it is determined that the notification mode is on (S1, Yes), the control unit 20 determines whether or not the external storage device 110 is connected to the storage device connection unit 15 (S2). When it is determined that it is connected (S2, Yes), the control unit 20 does not perform the notification in S5 and executes the image forming process (S6). When it is determined that it is not connected (S2, No), the control unit 20 determines whether the image quality used for image formation is high quality or low quality by referring to the image data (S3). When it is determined that the image quality is high (S3, High), the control unit 20 causes the touch panel display 16 to perform a notification prompting the connection of the external storage device 110 to the storage device connection unit 15 (S5). As a specific example, a message shown in FIG. 16, "The external storage device is not connected. Since recovery printing is performed when a jam occurs, connection of the external storage device is recommended." is displayed on the touch panel display 16. Then, the control unit 20 executes the image forming process (S6).

[0046] In S3, when it is determined that the image quality is low (S3, Low), the control unit 20 determines whether the type of paper used for image formation is plain paper or other types by referring to the image data (S4). When it is determined that the paper is plain paper (S4, Plain), the control unit 20 does not perform the notification in S5 and executes the image forming process (S6). When it is determined that the paper is other than plain paper, that is, glossy paper or inkjet paper (S4, Other than Plain), the control unit 20 causes the touch panel display 16 to perform the above notification (S5). Then, the control unit 20 executes the image forming process (S6).

[0047] According to the present embodiment described above, the raster processing unit 23 transfers raster data not only from the host area 21a or the intermediate buffer area 21b to the raster processing area 21c, but also to the external storage device 110. Therefore, when an interruption of the image forming process occurs, even if the storage capacity for the recovery process is insufficient only by using the storage unit 21, a recovery process based on the data stored in the external storage device 110 is possible.

[0048] Also, according to the present embodiment, during the recovery process, not only the external storage device 110 but also the data stored in the storage unit 21 at the time of interruption is appropriately used. Therefore, the data remaining in the storage unit 21 at the time of interruption can be effectively utilized.

[0049] Also, according to the present embodiment, as shown in FIG. 6, due to the insufficient capacity of the storage unit 21, the data related to the first page, which is the interrupted page, may not remain in the raster processing area. In this case, in the subsequent recovery process, for the first page, the image forming operation is performed based on the data stored in the external storage device 110 (see FIG. 7), and for the second page where data remains in the raster processing area, the image forming operation related to the second page is performed based on it (see FIG. 8). Thus, even if the capacity of the storage unit 21 is insufficient, the recovery process can be appropriately executed. Note that even when the data of the interrupted page remains incompletely in the storage unit 21 at the time of interruption, similarly, for the first page, the image forming operation is performed based on the data stored in the external storage device 110, and for the second page, the image forming operation is performed based on the data remaining in the raster processing area. Also, when the data after the third page remains in the raster processing area, the image forming operation related to the pages after the third page may be performed based on it.

[0050] Also, in the recovery process according to the present embodiment, in order to perform the image forming operation for the first page, when data is transferred from the external storage device 110 to the raster processing area 21c, the transfer is performed so as not to overwrite the data corresponding to the second page, which is the next page of the interrupted page, in the raster processing area 21c (see FIG. 7). Therefore, the image forming operation based on the data of the second page in the raster processing area 21c is ensured.

[0051] Also, in the recovery process according to the present embodiment, when the image forming operation based on the data left in the raster processing area 21c (the data on the second page in FIGS. 8 and 9) is completed, if the data of the entire page (the third page in FIGS. 8 and 9) consecutive to the last page (the second page in FIGS. 8 and 9) related to the image forming operation is in the external storage device 110, the image forming operation based on it is performed (see FIG. 9).

[0052] Also, in the recovery process according to the present embodiment, when the image forming operation based on the data left in the external storage device 110 (the data on the third page in FIGS. 8 and 9) is completed, for the page (the fourth page in FIGS. 8 and 9) consecutive to the last page (the third page in FIGS. 8 and 9) related to the image forming operation, an image forming operation based on the same process as the normal process shown in FIG. 3 or FIG. 4 is performed (see FIG. 10). That is, image formation is appropriately performed based on the raster data newly transferred from the host area 21a or the intermediate buffer area 21b to the raster processing area 21c.

[0053] Also, in the present embodiment, as shown in FIG. 11, due to the insufficient capacity of the storage unit 21, there may be a case where only the data from the middle of the first page, which is the interrupted page, remains in the raster processing area 21c. In this case, in the recovery process, by using the data stored in the external storage device 110, an image forming operation is performed from the beginning of the interrupted page to the portion corresponding to the data stored last in the external storage device 110 (see FIGS. 12 and 13). Also, for the subsequent portion, image formation is appropriately performed based on the raster data transferred from the host area 21a or the intermediate buffer area 21b to the raster processing area 21c.

[0054] Also, in this embodiment, when the notification mode is on, if the image quality indicated by the image data and the type of paper satisfy predetermined conditions and the external storage device 110 is not connected to the storage device connection unit 15, a notification prompting the connection of the external storage device 110 is made. The predetermined conditions are that the image quality is high or the type of paper is other than plain paper. When such conditions are satisfied, the total amount of image data acquired from the external device 120 is large, and there is a high possibility that the storage capacity of the storage unit 21 will be insufficient. Since the above-mentioned notification is made in such a case, it is less likely that a situation where recovery processing cannot be performed due to insufficient capacity of the storage unit 21 will occur.

[0055] Note that, as a modified example of this embodiment, the control unit 20 may execute the process shown in FIG. 17 instead of the process shown in FIG. 15. First, the control unit 20 determines whether the image quality used for image formation is high image quality or low image quality by referring to the image data (S11). If it is determined that the image quality is high (S11, High), the control unit 20 determines whether the external storage device 110 is connected to the storage device connection unit 15 (S12). If it is determined that it is not connected (S12, No), the control unit 20 executes the image formation process 2 (S15). The image formation process 2 will be described later. If it is determined that it is connected (S12, Yes), the control unit 20 executes the image formation process 1 (S13). The image formation process 1 is the above-described image formation process that involves transferring raster data to the external storage device 110 as well as the raster processing area 21c in order to perform the recovery process shown in FIGS. 3 to 14 when the process is interrupted.

[0056] In S11, if it is determined that the image quality is low (S11, Low), the control unit 20 determines whether the type of paper used for image formation is plain paper or other types by referring to the image data (S14). If it is determined that it is other than plain paper (S14, Other than plain), the control unit 20 executes the process of S12. On the other hand, if it is determined that it is plain paper (S14, Plain), the control unit 20 executes the image formation process 2 (S15).

[0057] The image formation process 2 is a process that causes the image forming unit 10 to perform the image forming operation without transferring the raster data to the external storage device 110. Specifically, as shown in FIG. 18, the raster data is transferred from the host area 21a or the intermediate buffer area 21b to the raster processing area 21c, and further the raster data R1 is transferred to the image forming operation area. Then, an image forming operation based on the raster data R3 stored in the image forming operation area is performed.

[0058] When the image formation process 2 in S15 is interrupted due to a jam or the like, the control unit 20 executes the processes after S16. The control unit 20 determines whether it can execute the recovery process only with the data in the storage unit 21 (S16). This determination is made based on whether the data related to the entire interrupted page remains in the storage unit 21. If the data related to the entire interrupted page remains in the storage unit 21, the control unit 20 determines that the execution of the recovery process is possible (S16, Yes). In this case, the control unit 20 executes an image forming operation based on the data stored in the storage unit 21 in the recovery process (S17).

[0059] On the other hand, if the data related to the entire interrupted page does not remain in the storage unit 21, the control unit 20 determines that the execution of the recovery process is not possible (S16, No). In this case, the control unit 20 causes the touch panel display 16 to perform a notification to prompt connecting the external storage device 110 to the storage device connection unit 15 so that the recovery process can be ensured at the next interruption (S8). As a specific example, a message shown in FIG. 18, "Recovery printing could not be performed because the external storage device was not connected. Connecting the external storage device is recommended in case of a jam occurring next time." is displayed on the touch panel display 16. Then, the control unit 20 does not perform the recovery process and ends the series of processes.

[0060] According to the processing of FIG. 17 as described above, when the image quality is high (S11, high) or the paper is other than plain paper (S14, other than plain), the image forming process 1 is executed (S13). When the image quality is high or the paper is other than plain paper, the total amount of image data or the raster data after analysis is large, and there is a high possibility that the storage capacity of the storage unit 21 will be insufficient. In such a case, the control unit 20 predicts that the total amount of image data or the raster data after analysis will exceed the free capacity of the storage unit 21, and executes the image forming process 1. That is, as described above, the raster data is stored in the external storage device 110 and the data is used during the recovery process. Therefore, the recovery process is appropriately ensured. On the other hand, when the image quality is low (S11, low) and the paper is plain paper (S14, plain), the control unit 20 predicts that the total amount of image data or the raster data after analysis will not exceed the free capacity of the storage unit 21, and executes the image forming process 2 (S15). That is, the raster data is not stored in the external storage device 110. In this way, according to the prediction of whether or not the capacity of the storage unit 21 is insufficient for the image data, it is appropriately determined whether or not to store the data in the external storage device 110.

[0061] Also, when the external storage device 110 is not connected to the storage device connection unit 15 (S12, No), the image forming process 2 is executed and the data is stored only in the storage unit 21. Therefore, when an interruption of the image forming process 2 occurs, if the data of the entire interrupted page remains due to insufficient capacity of the storage unit 21, that is, if none remains at all or even if some remains, it is incomplete, the recovery process cannot be executed (S16, No). In this case, a notification prompting the connection of the external storage device 110 is made (S18). Therefore, the user is alerted to connect the external storage device 110 in preparation for the next interruption.

[0062] <Other Modification Examples> As described above, the embodiments of the present invention have been described with reference to the drawings. However, the specific configuration should be considered not to be limited to these embodiments. The scope of the present invention is defined by the claims, rather than the description of the above embodiments, and further includes all modifications within the meaning and scope equivalent to the claims.

[0063] For example, in the above-described embodiment, the USB method is adopted for the interface unit of the storage device connection unit 15. Instead of this, a wired LAN (Local Area Network) method, a wireless LAN, or other various wireless communication methods may be adopted for the interface unit of the storage device connection unit 15. Further, as the external storage device 110, in addition to the USB memory, a storage device connected by USB, wired LAN, or various wireless communication methods may be adopted.

[0064] Also, the recovery process according to the above-described embodiment is premised on using the data remaining in each of the external storage device 110 and the storage unit 21 at the time of interruption of the image formation process. Instead of this, it may be premised on using only the data remaining in the external storage device 110 at the time of interruption of the image formation process.

[0065] In addition, in the above-described embodiment, the case where the present invention is applied to the printer 1 has been described, but it is not limited thereto. The present invention may be applied to other inkjet type image forming apparatuses that eject ink from a head, such as a multifunction device, a copying machine, etc., or a system having these image forming apparatuses. Further, instead of attaching ink to the printing paper by the inkjet method, the present invention may be applied to a laser type image forming apparatus that executes an image recording process by attaching toner to the printing paper. In this case, a toner cartridge for storing toner is detachably attached to the image forming apparatus.

Description of Reference Numerals

[0066] 1 Printer 10 Image Forming Unit 15 Storage Device Connection Unit 16 Touch panel display 20 Control unit 21 Memory unit 23 Raster processing unit 110 External storage device

Claims

1. an image forming unit that forms an image on a print medium; a connection unit that can be connected to an external storage medium; a storage unit; and a control unit, wherein the control unit performs a first storage process of storing the image data received from an external device or the data after its analysis in each of the storage unit and the external storage medium connected to the connection unit; an image forming process of causing the image forming unit to perform the image forming based on the data stored in the storage unit; and when an interruption of the image forming process occurs, based at least on the external data at the time of interruption, which is the data stored in the external storage medium at the time of interruption, the image forming unit is caused to perform again the image forming related to the image forming process in which the interruption has occurred on a print medium different from the print medium on which the image forming was being performed at the time of interruption, which is a re-image forming process, and an image forming apparatus characterized by this.

2. The image forming apparatus according to claim 1, wherein the re-image forming process is performed based on both or the latter of the internal data at the time of interruption, which is the data stored in the storage unit at the time of interruption, and the external data at the time of interruption.

3. wherein the control unit when the internal data at the time of interruption does not include data corresponding to at least a part of the interrupted page, which is the page on which the image forming was being performed at the time of interruption, and includes data corresponding to the whole of one or more pages consecutive to the interrupted page, as the re-image forming process, causes the image forming unit to perform a first image forming, which is the image forming based on the external data at the time of interruption, on the interrupted page, and causes the image forming unit to perform a second image forming, which is the image forming based on the internal data at the time of interruption, on one or more pages consecutive to the interrupted page, and an image forming apparatus characterized by this according to claim 2.

4. The first image forming is performed based on the data transferred after the data corresponding to the interrupted page is transferred from the external storage medium to an area other than the area where the data corresponding to the page next to the interrupted page is stored in the storage unit, and the second image forming is performed based on the data corresponding to the pages after the next page stored in the storage unit when the transfer of the data corresponding to the interrupted page is completed, and an image forming apparatus characterized by this according to claim 3.

5. wherein the control unit When the external data at the time of interruption includes data corresponding to the entire one or more pages consecutive to the last page related to the second image formation, The image forming apparatus according to claim 3, wherein, as the re-image forming process, after the second image formation, the image forming unit is caused to perform a third image formation which is the image formation based on the data corresponding to one or more pages consecutive to the last page.

6. The control unit, As the re-image forming process, For one or more pages consecutive to the last page related to the external data at the time of interruption, the first storage process is performed, and thereby the image forming unit is caused to perform the image formation based on the data stored in the storage unit. The image forming apparatus according to any one of claims 3 to 5.

7. The control unit, When the internal data at the time of interruption is data corresponding to after the middle of the interrupted page which is the page on which the image formation was being performed at the time of interruption, As the re-image forming process, In the external data at the time of interruption, the image forming unit is caused to perform the image formation based on the data from the data corresponding to the head of the interrupted page to the data last stored by the first storage process, and for the subsequent image formation, the first storage process is performed and thereby the image forming unit is caused to perform the image formation based on the data stored in the storage unit. The image forming apparatus according to claim 1.

8. The image data is either raster image data including first raster data or vector image data including vector data including a plurality of commands for instructing the content of the image formation, The first storage process is a process of storing the first raster data for the raster image data and second raster data obtained by analyzing the plurality of commands included in the vector data for the vector image data in the storage unit and the external storage medium respectively, The control unit, Executes the first storage process while sequentially counting the data sizes stored in the storage unit and the external storage medium for both the raster image data and the vector image data, The image forming apparatus according to claim 7, wherein, among the external data at the time of interruption, which data was last stored by the first storage process is acquired according to the data size.

9. further comprising a notification unit, wherein the control unit, when the external storage medium is not connected to the connection unit, executes a second storage process for storing the image data or the data after analysis thereof only in the storage unit, when the interruption occurs, if the internal data at the time of interruption does not include data corresponding to at least a part of the interrupted page which is the page on which the image formation was being performed at the time of the interruption, causes the notification unit to give a notification prompting connection of the external storage medium, the image forming apparatus according to claim 1.

10. further comprising a notification unit, wherein the image data indicates at least one of the image quality used in the image formation and the type of the printing medium, wherein the control unit, when at least one of the image quality and the type of the printing medium satisfies a predetermined condition based on the image data and the external storage medium is not connected to the connection unit, before starting the first storage process, causes the notification unit to give a notification prompting connection of the external storage medium, the image forming apparatus according to claim 1.

11. whether to give the notification can be set in advance by the user, wherein the control unit, when it is set to give the notification, causes the notification unit to give the notification, the image forming apparatus according to claim 9 or 10.

12. wherein the control unit, predicts whether the total amount of the image data or the data after analysis thereof exceeds the free capacity of the storage unit based on the content of the image data, and when it is predicted that the total amount exceeds, executes the first storage process, and when it is predicted that the total amount does not exceed, executes a second storage process for storing the image data or the data after analysis thereof only in the storage unit, the image forming apparatus according to claim 1.

Images