In the following, embodiments of the present invention will be described with reference to the accompanying drawings.
The CPU 1 processes a program so as to instruct or control each block and realize functions of the image formation apparatus 100 according to the present embodiment. The ROM 2 stores the program processed by the CPU 1 and various types of data and the like used in the program. The RAM 3 is used via the RAM control unit 4 as a storage area for temporarily storing data and the like processed by the CPU 1 and the like. The scanner engine 5 is an image input unit reading a document image in the copying function and the scanner function. The NCU 9 is a device connecting to a public communication network and transmitting a dial signal so as to call a communication target. The FAX control unit 10 controls the FAX function. For example, the FAX control unit 10 decodes data received via the NCU 9 upon FAX reception and generates print data for causing the printer engine 19 to perform printing. A transmission image upon FAX transmission may be input from an external host device 11 other than the scanner engine 5.
The host I/F control unit 12 receives the print data from the external host device 11 as an image input unit in the printing function. An interface controlled by the host I/F control unit 12 is not limited to a specific element. Examples of connection include local connection such as IEEE 1284, USB, and network connection such as wired or wireless Ethernet (registered trademark). The operation unit 16 is an operation panel functioning as a man-machine interface to a user, including buttons for allowing operation of the image formation apparatus 100, indicators for displaying a status (indicators such as an LED, LCD, and speaker), and the like. The operation unit I/F control unit 17 inputs and outputs information to the operation unit 16. The printer engine 19 is a printout unit. An imaging method is not limited to a specific method and may be any one of a laser method, LED method, ink-jet method, and the like. The NVRAM 21 is a non-volatile memory and is used to store device-specific information (such as a counter value of a number of copies).
The display unit 302 displays a character string, bitmap image, and the like. Further, the display unit 302 includes a touch panel and is used so as to operate setting such as reading conditions. The numeric keypad 303 is used for operation such as input of the number of copies. The reset key 304 is used upon resetting a copy mode. The start key 305 is used for operation instructing a start of copying or document reading. The application switching key 306 is used for operation switching among the copier function, printer function, scanner function, and the like. The clear/stop key 307 is used upon suspending copying and resetting the number of copies. The initial setting key 308 is used upon setting an initial value of various parameters used for the copier function, printer function, scanner function, and the like.
The total control unit 201 controls an entire portion of process performed by the CPU 1. For example, the total control unit 201 controls the operation unit 16, host I/F control unit 12, FAX control unit 10, and the like. Control conditions are set via the operation unit 16.
The data accumulation control unit 202 manages an area for storing image data (hereafter referred to as an image storage area) input from an input unit such as the scanner engine 5, host I/F control unit 12, and the like, the image storage area being disposed on a portion of the RAM 3. The scanner reading control unit 203 controls the scanner engine 5. The plotter printing control unit 204 controls the printer engine 19. The data storage control unit 205 predicts, when image data is read using the scanner engine 5, a data amount required for accumulating the image data in the image storage area. The data amount predicted by the data storage control unit 205 is hereafter referred to as a “predicted data amount”. The predicted data amount is judged based on reading conditions (including resolution, paper size, black and white/color, and the like), a correspondence table (hereafter referred to as a predicted data amount table) in which the reading conditions correspond to accumulated data amount, and the like. The predicted data amount table is stored in the NVRAM 21 or the ROM 2.
In the following, the image storage area in the RAM 3 is described in detail.
In program data area P, various types of application programs are loaded. The data area D stores various types of conditions set in the image formation apparatus 100 and calculated values upon executing the program. The image storage area G stores image data input from the input unit such as the scanner engine 5, host I/F control unit 12, and the like as mentioned above. As shown in
The accumulation capacity Sa indicates a maximum capacity available for accumulating image data. The total amount Σs of accumulated image data indicates a total of data amount of all image data accumulated in the image storage area G. The accumulated amount Sf for switching predicted data amounts is a threshold for switching predicted data amounts of image data to be newly accumulated. The data accumulation control unit 202 detects the available capacity Se of the image storage area G based on the accumulation capacity Sa and the total amount Σs of accumulated image data. Specifically, the available capacity Se of the image storage area G is detected by subtracting the total amount Σs of accumulated image data from the accumulation capacity Sa.
In
The following describes a process of the image formation apparatus 100 in
First, the data storage control unit 205 judges predicted data amount Sy of image data to be newly read (hereafter referred to as “reading image”) based on the reading conditions and the like (S201). Details of this process are described later.
Then, the total control unit 201 obtains the available capacity Se of the image storage area G from the data accumulation control unit 202 and judges whether to accumulate the reading image in the image storage area G (S202). In other words, if Se≧Sy, the total control unit 201 judges that reading is possible and starts image reading (S203). On the other hand, if Se<Sy, the total control unit 201 judges that reading is impossible and stops the image reading (S204).
In general, when the reading conditions (including resolution, paper size, black and white/color, and the like) are determined, it is possible to calculate data amount of a reading image. However, the predicted data amount Sy is used in the present embodiment because image data is compressed and accumulated so as to reduce consumption of the memory area as much as possible. The data amount after the compression of the image data is different depending on a compression method the image data, so that the data amount is not determined in accordance with the reading conditions. It is obvious that when the image data is compressed, it is possible to determine the data amount after the compression. However, in such a case, it is impossible to judge whether to accumulate unless image data is read. In view of this, the image formation apparatus 100 judges the predicted data amount Sy for the data amount of the reading image and judges whether to accumulate based on the predicted data amount Sy. In accordance with this, it is possible to judge whether to accumulate image data before the image data is read.
The predicted data amount Sy is intended to be prediction, so that the data amount is not necessarily accurate. Thus, when the predicted data amount Sy is smaller than an actual data amount, namely, when the data amount is undervalued, memory full may be generated. In view of this, at least two values may be held as predicted data amounts. For example, one predicted data amount is an average value of the data amount determined in accordance with contents of a document, the reading conditions, and the compression method. The other predicted data amount is a maximum data amount (maximum value) predicted in accordance with the contents of the document, reading conditions, and compression method. The average value and the maximum value may be obtained by collecting data using a test and the like or may be calculated theoretically. In the following, the average value is referred to as “predicted data amount Sy1” and the maximum value is referred to as “predicted data amount Sy2”. When the two predicted data amounts are used, two predicted data amounts are registered in the predicted data amount table.
However, it is not efficient to judge whether to accumulate always based on the two predicted data amounts Sy. In view of this, the image formation apparatus 100 switches the two predicted data amounts in accordance with a certain condition.
The data storage control unit 205 compares the accumulated amount Sf for switching predicted data amounts with the total amount Σs of accumulated image data obtained from the data accumulation control unit 202 (S211). In addition, the accumulated amount Sf for switching predicted data amounts may be registered in an area of the ROM 2 or the NVRAM 21 to which the data storage control unit 205 is capable of referring or may be automatically calculated upon performing copying and the like.
If the total amount Σs of accumulated image data is not more than the accumulated amount Sf for switching predicted data amounts (No, in S211), the data storage control unit 205 employs the predicted data amount Sy1 (average value) as the predicted data amount Sy (S212). On the other hand, if the total amount Σs of accumulated image data exceeds the accumulated amount Sf for switching predicted data amounts (Yes, in S211), the data storage control unit 205 employs the predicted data amount Sy2 (maximum value) as the predicted data amount Sy (S213).
A value of the accumulated amount Sf for switching predicted data amounts may be determined based on the maximum value of the data amount after the compression determined in accordance with the specification of the image formation apparatus 100, for example. In other words, the accumulated amount Sf for switching predicted data amounts is obtained by subtracting the maximum value from the accumulation capacity Sa. In addition, the maximum value of the data amount after the compression determined in accordance with the specification of the image formation apparatus 100 refers to image data amount after the compression with least efficient compression when a maximum size document that the image formation apparatus 100 is capable of reading is read in a maximum resolution. Further, when the image formation apparatus 100 is capable of reading a color image, color reading is also considered.
By determining the accumulated amount Sf for switching predicted data amounts in this manner and switching the predicted data amounts Sy as shown in
In addition, the process shown in
In the following, obtaining of the predicted data amount Sy is described. First, an example where the predicted data amount Sy is judged based on resolution is described. When the predicted data amount Sy is judged based on the resolution, the predicted data amount table is constructed as shown in
After the reading conditions set in the operation unit 16 are determined using the start key 305, when the resolution in the determined reading conditions is 600 dpi×600 dpi, for example, data amount of a reading image is predicted to be two times a case where the resolution is 300 dpi×300 dpi in a main scanning direction and a sub-scanning direction. Thus, the data storage control unit 205 judges the predicted data amount Sy to be 4X based on the predicted data amount table 250a. On the other hand, when the resolution in the determined reading conditions is 300 dpi×300 dpi, the data storage control unit 205 judges the predicted data amount Sy to be X. In other words, when there is no item corresponding to the set resolution in the predicted data amount table 250a, the data storage control unit 205 judges the predicted data amount Sy based on the registered information. However, if the ROM 2 or the NVRAM 21 is sufficiently available, predicted data amount may be registered for each of all the resolutions which can be set in the image formation apparatus 100.
The prediction based on the resolution as mentioned above is effective and appropriate prediction is possible when the image formation apparatus 100 is a monochrome device and an image area (image size) that can be specified upon reading is small. In the predicted data amount table 250a of
Next, an example where the predicted data amount Sy is judged based on color information is described. When the predicted data amount Sy is judged based on the color information, the predicted data amount table is constructed as shown in
After the reading conditions set in the operation unit 16 are determined using the start key 305, when the color information in the determined reading conditions is full color, data on four colors of C (cyan), M (magenta), Y (yellow), and K (black) is required, so that the data amount of a reading image is predicted to be four times the case of a monochrome image. Thus, the data storage control unit 205 judges the predicted data amount Sy to be 4X based on the predicted data amount table 250b. On the other hand, when the color information in the determined reading conditions is monochrome, the data storage control unit 205 judges the predicted data amount Sy to be X. In other words, when there is no item corresponding to the set color information in the predicted data amount table 250b, the data storage control unit 205 judges the predicted data amount Sy based on the registered information. However, if the ROM 2 or the NVRAM 21 is sufficiently available, predicted data amount may be registered for each of all the color information which can be set in the image formation apparatus 100.
The prediction based on the color information as mentioned above is effective and appropriate prediction is possible when the image formation apparatus 100 is a color device and the image area that can be specified upon reading is small. In the predicted data amount table 250b of
Next, an example where the predicted data amount Sy is judged based on the image area upon storing in a storage unit is described. When the predicted data amount Sy is judged based on the image area, the predicted data amount table is constructed as shown in
After the reading conditions set in the operation unit 16 are determined using the start key 305, when the image area in the determined reading conditions is A5, the data storage control unit 205 judges the predicted data amount Sy to be ½X based on the predicted data amount table 250c since the image area of A5 is a half (½) of that of A4. On the other hand, when the image area in the determined reading conditions is A4, the data storage control unit 205 judges the predicted data amount Sy to be X. In other words, when there is no item corresponding to the set image area in the predicted data amount table 250c, the data storage control unit 205 judges the predicted data amount Sy based on the registered information. However, if the ROM 2 or the NVRAM 21 is sufficiently available, predicted data amount may be registered for each of all the image areas which can be set in the image formation apparatus 100.
The prediction based on the image area as mentioned above is effective when the image formation apparatus 100 is a device with a wide range of supported sizes such as an A3-capable device, for example. In the predicted data amount table 250c of
Next, an example where the predicted data amount Sy is judged based on the compression method is described. When the predicted data amount Sy is judged based on the compression method, the predicted data amount table is constructed as shown in
After the reading conditions set in the operation unit 16 are determined using the start key 305, when the determined reading conditions are specified such that read image data is stored in the non-compression mode (YES, in S1101), the data storage control unit 205 judges the predicted data amount Sy to be X based on the predicted data amount table 250d (S1103).
On the other hand, when the reading conditions are specified such that the read image data is stored in the binary compression mode (YES, in S1102), the data storage control unit 205 judges the predicted data amount Sy to be Y based on the predicted data amount table 250d (S1104).
The prediction based on the compression methods as mentioned above is effective when various types of compression methods such as non-compression, binary compression, JPEG compression, and the like are prepared upon accumulating data and data amount after the compression is greatly changed depending on the compression methods. Examples of such a change include a case where the image formation apparatus 100 provided with an electronic sorting function and the like performs compression and accumulation when a large amount of data needs to be accumulated for the electronic sorting while normally performing accumulation in the non-compression mode. In the predicted data amount table 250d of
In the following, a specific example in which the examples mentioned above are combined is described.
In a predicted data amount table 250e shown in
After the reading conditions set in the operation unit 16 are determined using the start key 305, it is assumed that the compression method is compression B, the color information is full color, the image area is A4, and the resolution is 600 dpi×600 dpi in the determined reading conditions. The reading conditions (hereafter referred to as “reading condition A”) correspond to the bottom item in the predicted data amount table 250e. In the following, a relevant item is referred to a “corresponding item”.
First, the data storage control unit 205 calculates the accumulated amount Sf for switching predicted data amounts (S2201). In the corresponding item of the predicted data amount table 250e, the maximum value of the predicted data amount is 5Z. In other words, in the reading condition A, image data not less than 5Z is not accumulated. Thus, the data storage control unit 205 sets “accumulation capacity Sa-5Z” as the accumulated amount Sf for switching predicted data amounts.
In this case, in order to prevent generation of memory full, a value capable of holding 5Z (predicted data amount Sy2) as the available capacity Se in the image storage area G is determined as the accumulated amount Sf for switching predicted data amounts. However, the accumulated amount Sf for switching predicted data amounts may be determined in accordance with other standard. For example, upon performing copying operation, when images may be accumulated by reading ahead documents to such an extent that a printing speed is not affected therefrom, if a number of documents to be read ahead is 2, 2×5Z (total amount Σs of accumulated image data when reading is performed in the maximum size upon compression) may be determined as the accumulated amount Sf for switching predicted data amounts.
Then, the data storage control unit 205 compares the calculated accumulated amount Sf for switching predicted data amounts with the total amount Σs of accumulated image data (S2202). If the total amount Σs of accumulated image data is not more than the accumulated amount Sf for switching predicted data amounts (NO, in S2202), the data storage control unit 205 employs 3Z, which is the average value of the predicted data amount, as the predicted data amount Sy (S2203). Subsequently, the total control unit 201 obtains the available capacity Se of the image storage area G from the data accumulation control unit 202 and judges whether to accumulate the reading image in the image storage area G (S2205). In other words, if the available capacity Se is not less than 3Z (YES, in S2205), the reading is judged to be possible and image reading is started (S2206). After the reading operation is ended, an actual data amount of the reading image is determined and the data accumulation control unit 202 renews the total amount Σs of accumulated image data using the determined data amount (S2208).
In addition, when the next document to be read is present (YES, in S2209), the process from the step S2202 is repeated. As a result of the repetition of the steps S2202 to S2209, when the total amount Σs of accumulated image data becomes larger than the accumulated amount Sf for switching predicted data amounts (YES, in 2202), the data storage control unit 205 employs 5Z, which is the maximum value of the predicted data amount, as the predicted data amount Sy (S2204).
If the available capacity Se is smaller than the predicted data amount Sy (NO, in S2205), the total control unit 201 judges that reading is impossible and stops the image reading (S2207). However, instead of immediately stopping the reading operation, it is possible to wait for the total amount Σs of accumulated image data to be reduced by being deleted from the image storage area G in accordance with output (printing, for example) of the accumulated data and to perform the process from S2202 again.
As mentioned above, in the image formation apparatus 100 according to the present invention, whether to perform accumulation is judged not only from the available capacity of the memory but also from the reading conditions. Thus, it is possible to efficiently perform accumulation of image data in the memory and to prevent generation of memory full. Further, even when the image data is compressed and accumulated, data amount after the compression is predicted so as to perform accumulation, so that it is possible to judge whether to perform accumulation before reading the image data.
The present embodiment is described mainly on the basis of the case where the image data is compressed and accumulated. However, even when the image data is not compressed, it is possible to apply the technique of judging whether to perform accumulation from the reading conditions. In this case, the data amount of the reading image is readily calculated from the reading conditions, so that whether to perform accumulation may be judged based on the calculated data amount instead of the predicted data amount Sy.
The present invention is not limited to the specifically disclosed embodiment, and variations and modifications may be made without departing from the scope of the present invention.
The present application is based on Japanese priority application No. 2006-230789 filed Aug. 28, 2006, the entire contents of which are hereby incorporated herein by reference.
Number | Date | Country | Kind |
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2006-230789 | Aug 2006 | JP | national |