JP4269508B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus that converts print data expressed in a page description language (PDL) or the like into image data expressed in a bitmap or the like and uses it for image formation.
[0002]
[Prior art]
2. Description of the Related Art In recent years, image forming systems in which image forming apparatuses such as digital copying machines and printers are connected via a network such as a LAN and the image forming apparatuses are shared by a plurality of terminal devices such as personal computers (PCs) have been widely put into practical use. .
When the image forming apparatus is connected to the network in this way, when transferring data representing an image from the terminal device to the image forming apparatus, the amount of data to be transferred when the image data is transferred in the already developed image data format such as a bitmap format. Will become enormous, leading to a decrease in network utilization efficiency. Therefore, for example, the image data is transferred in the form of data representing an image to be formed (hereinafter referred to as “print data”) expressed in a language such as a page description language (PDL), and converted into image data on the image forming apparatus side. It is common to deploy.
[0003]
On the other hand, many recent image forming apparatuses have a so-called electronic sort function. Here, the electronic sort function refers to a function for forming a plurality of images for each part, instead of forming a plurality of images for each image when a plurality of images are formed. Therefore, for example, when a plurality of copies are instructed from the terminal device and the electronic sort function is used, even if image formation for the first part is completed, image formation for the second and subsequent copies is performed. For this purpose, print data or image data (hereinafter collectively referred to as “image data”) is usually stored on the image forming apparatus side.
[0004]
[Problems to be solved by the invention]
By the way, when image data is stored on the image forming apparatus side for image formation for the second and subsequent copies, the image data once developed is discarded and stored in the form of print data or stored in the form of image data. It will be a problem. In other words, it is easy to imagine that it is ideal to hold the image data in the form of image data from the viewpoint of productivity of performing image formation more quickly. This is because it is not necessary to develop the image data again when forming the second and subsequent images, and it is possible to perform image formation without interruption.
[0005]
However, since the amount of image data is usually much larger than that of print data, the capacity of storage means such as an image memory is increased in order to retain all image data in the form of image data. This is not desirable from the viewpoint of cost reduction of the image forming apparatus.
The present invention has been made in view of the above problems, and provides an image forming apparatus capable of preventing image formation productivity deterioration while suppressing an increase in the capacity of a storage unit. It is aimed.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an image forming apparatus according to the present invention is an image forming apparatus that converts data in a first format representing an image to be formed into data in a second format and uses it for image formation. Conversion means for converting data in the first format into data in the second format, storage means for storing data in the first format or data in the second format, and the data amount of the data in the first format First acquisition means for acquiring, second acquisition means for acquiring the data amount of data in the second format, and a value corresponding to the data amount of data in the first format as a reference value, the second format When the data amount of the data is smaller than the reference value, the data in the second format is stored in the storage means. In other cases, the data in the first format is stored in the storage means. and control means for controlling for each image, the control Stage is characterized in that the said first type of data amount to zero value by adding a greater than a predetermined value of the data or 1 the reference value multiplied by a value of greater than a predetermined value.
[0007]
In this configuration, when the data amount of data in the second format (for example, bitmap format) is smaller than the reference value determined according to the data amount of data in the first format (for example, PDL), the second Control to store format data. By performing this control, it is possible to prevent deterioration in productivity while suppressing an increase in the capacity of the storage area.
[0008]
When storing in the storage means, as will be described later in the embodiment, data in both formats may be temporarily stored in the storage means, and either one of them may be deleted, or other temporary A memory for storage may be provided to temporarily store both types of data, and only one of them may be stored in the storage means.
As the reference value, a value obtained by adding a predetermined value to the data amount of the data in the first format can be used, or a value obtained by multiplying the data amount of the data in the first format by the predetermined value is used. Can do. However, it is not limited to these, and the method for determining the reference value is arbitrary.
[0009]
The image forming apparatus further includes a compression unit that compresses the data in the second format, and the second acquisition unit determines the amount of data compressed by the compression unit as data of the second format. When the acquired data amount is smaller than the reference value, the control unit can control to store the compressed data in the storage unit.
[0010]
The image forming apparatus further includes confidentiality determination means for determining whether the image to be formed has confidentiality from the data in the first format or the converted data, and the control means For the image determined to be confidential by the confidentiality determination means, it is preferable to control the storage means to store data of the first format. The determination of confidentiality can be performed with reference to information included in the data of the first format, for example.
Further, the control means executes control for each image for the image determined not to have confidentiality by the confidentiality determination means, and the image determined to have confidentiality by the confidentiality determination means. For the above, instead of the control for each image, the first format data is stored regardless of the data amount of the first format data and the data amount of the second format data. Control may be performed so as to delete the data in the second format.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an image forming apparatus according to the present invention will be described below with reference to the drawings.
(First embodiment)
(1) Overall Configuration of Image Forming System First, an image forming system including the image forming apparatus of the present embodiment will be described. FIG. 1 is a block diagram showing the overall configuration of the image forming system. As shown in the figure, the image forming system is a digital copier (hereinafter simply referred to as “copier”) that forms an image based on image data generated by reading a document or data transferred from the outside. 100) PC or the like on which software (hereinafter referred to as “printer driver”) for converting image data corresponding to a document created and edited using an application such as a word processor or drawing software into the print data is installed. Terminal device 200 and print server 300 that once spools the print data transferred from terminal device 200 via network 500 such as a LAN, and sequentially transfers the data to copying machine 100. For example, PostScript (registered trademark of Adobe Systems Incorporated) can be used as the print data expression format.
[0012]
In FIG. 1, only one copier 100 as an image forming apparatus and one terminal device 200 are shown, but a plurality of these can be connected. Further, it can be connected to an external device via a telephone line or the like.
Document image data such as a document created and edited by an application installed in the terminal device 200 is converted into print data of a predetermined format such as the PDL by the printer driver and transferred to the print server 300. The print data transferred to the print server 300 is once spooled in a storage device such as an HDD (hard disk drive) or a RAM provided in the print server 300, and sequentially sent to the copying machine 100 for image formation. The
[0013]
(2) Configuration of Copying Machine 100 Next, the configuration of the copying machine 100 according to the present embodiment will be described. FIG. 2 is a schematic cross-sectional view showing the overall configuration of the copying machine 100. As shown in the figure, the copying machine 100 includes an automatic document feeder (hereinafter referred to as “ADF”) 10, a document reading unit 30, a network management unit 40, an image forming unit 50, and a paper feeding unit 70. Yes.
[0014]
The ADF 10 is a device that automatically conveys a document to the document reading unit 30. That is, the original placed on the original tray 11 is conveyed to the original reading position on the platen glass 31. The document transported to the document reading position is scanned by the scanner 32 provided in the document reading unit 30 and is then fed again by the transport belt 12 in the right direction in the figure, and finally onto the document discharge tray 13. Discharged.
[0015]
The original reading unit 30 optically reads an image of the original conveyed to the original reading position on the platen glass 31, and includes the scanner 32, the CCD sensor 38, the scanner motor M2, and the like.
The scanner 32 is provided with an exposure lamp 33 and a mirror 34 for changing the optical path of light reflected from the original by irradiation of the exposure lamp 33 in a direction parallel to the platen glass 31, and the arrow a in the figure is driven by the scanner motor M2. The original on the platen glass 31 is scanned by moving in the direction. The reflected light from the original is reflected by the mirror 34 and then guided to the CCD sensor 38 via the mirrors 35 and 36 and the condenser lens 37, where it is converted into an electrical signal to generate an image signal.
[0016]
The generated image signal is A / D converted by the image processing unit 39 to become a digital signal, further subjected to known image processing such as shading correction and density conversion processing, and then stored in the memory unit 45. . The digital data stored in the memory unit 45 generates a drive signal of a laser diode (hereinafter referred to as “LD”) 51 described later via the print processing unit 46, and forms an image based on the drive signal. An image is formed by the unit 50.
[0017]
The network management unit 40 includes a print data receiving unit 41 that receives the print data transferred from the print server 300 via the network 500, and an image data control unit that develops the print data into image data such as a bitmap. 42 is included. The image data developed by the image data control unit 42 is sent to the print processing unit 46 and used for image formation.
[0018]
The image forming unit 50 forms an image on a recording sheet by a known electrophotographic method. As described above, the print processing unit 46 generates a drive signal for the LD 51 based on the digital data stored in the memory unit 45 and the image data sent from the image data control unit 42, and based on the drive signal. Then, the LD 51 is driven to emit laser light. The laser light is reflected by the mirror surface on the side of the polygon mirror 52 that rotates at a predetermined angular velocity, and exposes the surface of the photosensitive drum 56 that is driven to rotate in the direction of arrow b via the fθ lens 53 and the mirrors 54 and 55. Scan.
[0019]
A cleaning unit 57, an eraser lamp (not shown), a charging charger 58, and a developing device 59 are provided around the photosensitive drum 56, and detailed description of these operations is omitted. The paper feed unit 70 is provided with two cassettes 71 and 72, and a recording sheet having a required size is stored in either one of the cassettes 71 and 72 in synchronization with the exposure and development operations of the photosensitive drum 56. Paper is fed from. The fed recording sheet is conveyed below the photosensitive drum 56, and the toner image formed on the surface of the photosensitive drum 56 is transferred to the surface of the recording sheet.
[0020]
Thereafter, the recording sheet is separated from the surface of the photosensitive drum 56 and conveyed to the fixing unit 63 by the conveying belt 62. In the fixing unit 63, the toner image transferred on the surface of the recording sheet is fixed, and the recording sheet after fixing is discharged onto the paper discharge tray 66. Note that the paper conveyance and the driving of the photosensitive drum 56 as described above are controlled by the main motor M1.
[0021]
The copying machine 100 according to the present embodiment applies to a plurality of images based on a series of a plurality of documents read by the document reading unit 30 and a plurality of pages of documents transmitted via the network 500. A so-called electronic sort function is provided that can form a plurality of corresponding images for each part.
When this electronic sort function is used, since image formation is performed again for an image that has once been formed, image data is usually stored in the image forming apparatus. The gist of the present invention is to determine whether print data such as PDL transmitted via the PDL is stored in a format such as PDL or in a format of image data after development by a novel method. That is, by determining the format of data stored by the method of the present invention, an increase in the capacity of storage means such as a memory is suppressed, and deterioration in image formation productivity is prevented.
[0022]
(3) Configuration of Image Data Control Unit 42 Next, the detailed configuration of the image data control unit 42 that forms the gist of the present invention will be described. FIG. 3 is a functional block diagram showing a configuration of the image data control unit 42 of the present embodiment. The image data control unit 42 includes a print data memory 421, a data development control unit 422, and a buffer memory 423.
[0023]
In the print data memory 421, the print data received by the print data receiving unit 41 and once developed by the data development control unit 422 are stored in the form of image data, for example, in order to form a plurality of images thereafter. Data is stored. Specifically, various RAMs and HDDs can be used. In the figure, for convenience of explanation, the print data area 421a and the image data area 421b are shown separated by a dotted line, but physically, both types of data may be mixed. Hereinafter, the print data of the mth image may be represented by Pm, and the image data of the mth image may be represented by Mm. The same applies to FIG.
[0024]
The data development control unit 422 controls the development from the print data Pm to the image data Mm and the storage of the image data in the buffer memory 423 provided in the middle of the print processing unit 46. FIG. 4 is a diagram showing details of the configuration of the data development control unit 422. The data development control unit 422 includes a data development unit 501, a data amount acquisition unit 502, a storage format determination unit 503, and an image data deletion unit 504.
[0025]
The data expansion unit 501 expands print data into image data for each page and stores the image data in the buffer memory 423, and also temporarily stores the image data in the print data memory 421. The data amount acquisition unit 502 measures the data amount of the print data and the data amount of the image data for each image, and sends it to the storage format determination unit 503.
[0026]
The storage format determination unit 503 stores the print data in the print data memory 421 in the print data format based on the print data amount and the image data amount acquired by the data amount acquisition unit 502 or in the image data format. Determine whether to save. This determination method will be described in detail later. The data stored in the print data memory 421 is a second copy when an image that has already been formed is to be formed again. Specifically, for example, when a plurality of copies are formed using the electronic sort function, for example. This is used for subsequent image formation. In this case, the image stored in the print data format is expanded and used again by the data expansion unit 501 when the image is formed again, but the image stored in the image data format is used as it is. It can be used for image formation again, so that development time is not required. In the figure, the path for directly transferring the image data to the print processing unit 46 without passing through the buffer memory 423 is not shown.
[0027]
The image data deletion unit 504 receives the image data for the image determined to be stored in the print data format by the storage format determination unit 503 and the print data for the image determined to be stored in the image data format. Delete from 421. Thereby, for example, as shown in FIG. 3, there is no duplication of images stored in the print data memory 421.
[0028]
(4) Processing Contents in Image Data Control Unit 42 Next, details of specific processing contents performed in the image data control unit 42 will be described. What is important as a specific process of the image data control unit 42 is that the print data amount and the image data amount are acquired for each image, and based on the data amount, the subsequent processing (in this embodiment, two) is performed. This is a process for controlling whether image data is stored in the print data format or image data format in preparation for image formation for the second and subsequent copies). The focus is on.
[0029]
FIG. 5 is a flowchart showing the contents of the storage format determination process in the present embodiment. This processing can be performed, for example, after the development from the print data to the image data is completed for each image. This is because the data amount of the print data and the data amount of the image data can be acquired at this time.
That is, in the storage format determination process, first, the data amount acquisition unit 502 acquires the data amount of print data for the image (S101). The acquired data amount is hereinafter referred to as “print data amount”, and the print data amount for the m-th image is referred to as “PAm”. Next, the data amount acquisition unit 502 acquires the data amount of the image data expanded by the data expansion unit 501 (S102). The acquired data amount is hereinafter referred to as “image data amount”, and the image data amount for the m-th image is referred to as “MAm”.
[0030]
The data amount acquisition unit 502 sends each acquired data amount to the storage format determination unit 503. In the present embodiment, the storage format determination unit 503 compares the image data amount with a value obtained by adding a predetermined value (α) to the print data amount (S103). If the image data amount is smaller than a value obtained by adding a predetermined value of the print data amount (S103: Yes), the print data is deleted to store the image data for the image (S104). This is because, when the amount of image data is not so large in relation to the amount of print data, the image data is stored, thereby suppressing the increase in the capacity of the print data memory 421 and image formation productivity. It is intended to prevent a decrease. Accordingly, if the determination of No is made in step S103, the image data is deleted to save the print data for the image (S105).
[0031]
As described above, in the storage format determination control according to the present embodiment, the format of the image data is determined when saving the image data in the image data format does not lead to an increase in the capacity of the print data memory 421. Therefore, it is possible to prevent the deterioration of productivity while suppressing an increase in the capacity of the print data memory 421.
[0032]
In the above embodiment, the value obtained by adding the predetermined value (α) to the print data amount is compared with the image data amount as a reference value. However, the value obtained by multiplying the print data amount by the predetermined value (α) is used as a reference value. It may be a value. However, in any case, the specific value (α) is preferably optimized according to the capacity of the print data memory 421 or the like.
[0033]
In the above embodiment, the case where the image data is transferred directly from the image data control unit 42 to the print processing unit 46 for image formation has been described. However, the image data generated by expanding the print data is compressed. It is also possible to compress the image data and store it in the memory. In such a case, for example, the storage format may be determined by comparing the reference value determined based on the print data with the data amount of the compressed image data.
[0034]
Also, depending on the number of images to be stored, for example, when the amount of images to be stored in the image data format increases, it may be possible that the data of all images cannot be stored in the print data memory 421. Therefore, in such a case, control is performed so that the image data does not occupy a certain amount of capacity. For example, even when the image data is originally controlled to be stored in the image data format, the image data is stored in the print data format. You may make it perform processing, such as doing.
[0035]
(Embodiment 2)
In the present embodiment, a process in a case where print data of a confidential image is transmitted from the terminal device 200 will be described. That is, it is considered that it is not preferable to store the image-developed data in the image forming apparatus for confidential images, and therefore processing different from that in the first embodiment is performed. is there.
[0036]
FIG. 6 is a flowchart showing the contents of the storage format determination process in the present embodiment. As shown in the figure, in the present embodiment, first, it is determined whether or not the image represented by the print data is a confidential image (S201).
In this embodiment, when it is determined that the image data has confidentiality (S201: Yes), it is determined that the print data is stored unconditionally, that is, without considering the print data amount or the image data amount, and the image Data is deleted (S206). This is to maintain the confidentiality of the image by performing control such that the image data of the confidential image exists only temporarily in the image forming apparatus.
[0037]
Whether the image has confidentiality may be set using a function such as a document property provided in application software such as a word processor, or may be set by starting a printer driver. You may do it. In any case, the confidentiality information can be included in the PDL and transferred to the printer server 300, and the confidentiality of the image can be determined by referring to a predetermined portion of the PDL on the image forming apparatus side. Can do. In addition, since it is the same as that of 1st Embodiment in the case where it determines with having no confidentiality (S201: No), description is abbreviate | omitted.
[0038]
As described above, by performing the control of the present embodiment, for example, even when a paper jam or the like occurs in the image forming apparatus, confidential image data is held on the image forming apparatus side for a long period of time. Therefore, it is possible to contribute to prevention of leakage of confidential images.
<Modification>
Although the embodiments of the present invention have been described above, the content of the present invention is not limited to the specific examples shown in the above embodiments, and for example, consider the following modifications. Can do.
[0039]
(1) In the above embodiment, the print data memory 421 is provided separately from the memory unit 45, but these may be physically the same memory. In this case, the image compression means provided in the memory unit 45 may be used for compressing the image data generated by expanding the print data. (2) In the above embodiment, the case where the copying machine 100 is used as an example of the image forming apparatus has been described. However, the present invention can be applied to various image forming apparatuses such as a printer and a facsimile machine other than the copying machine. In addition, the image forming method is not limited to the electrophotographic method, and can be applied to various image forming methods.
[0040]
【The invention's effect】
As described above, according to the image forming apparatus of the present invention, there is an effect that it is possible to prevent deterioration in productivity while suppressing an increase in capacity of a storage unit that stores image data.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an overall configuration of an image forming system.
FIG. 2 is a schematic cross-sectional view showing the overall configuration of the copying machine 100. FIG.
3 is a functional block diagram showing a configuration of an image data control unit 42. FIG.
FIG. 4 is a diagram showing details of the configuration of a data development control unit 422;
FIG. 5 is a flowchart showing the contents of a storage format determination process in the first embodiment.
FIG. 6 is a flowchart showing the contents of a storage format determination process in the second embodiment.
[Explanation of symbols]
10 Automatic document feeder (ADF)
30 Document reading unit 39 Image processing unit 40 Network management unit 41 Print data receiving unit 42 Image data control unit 45 Memory unit 46 Print processing unit 50 Image forming unit 70 Paper feed unit 100 Copier 200 Terminal device 300 Print server 421 Print data storage Unit 422 data development control unit 423 buffer memory 500 network 501 data development unit 502 data amount acquisition unit 503 storage format determination unit 504 image data deletion unit

Claims (6)

In an image forming apparatus that converts data in a first format representing an image to be formed into data in a second format and uses it for image formation.
Conversion means for converting data in the first format into data in the second format;
Storage means for storing data in the first format or data in the second format;
First acquisition means for acquiring a data amount of data in a first format;
Second acquisition means for acquiring the amount of data in the second format;
A value corresponding to the data amount of the first format data is used as a reference value. When the data amount of the second format data is smaller than the reference value, the second format data is stored in the storage means. And control means for controlling each image so as to store data of the first format in the storage means in other cases ,
The control means includes
An image forming apparatus comprising: a value obtained by adding a predetermined value greater than 0 to a data amount of the first format data; or a value obtained by multiplying a predetermined value greater than 1 as the reference value . The image forming apparatus further includes:
Compression means for compressing data in the second format;
The second acquisition means includes
Obtaining the amount of data after compression by the compression means as the amount of data in the second format;
The control means includes
If the acquired data amount is smaller than the reference value, the image forming apparatus according to claim 1, wherein the controller controls to store the data after the compression in the storage means. The image forming apparatus further includes:
A confidentiality determining means for determining whether the image to be formed has confidentiality from the data in the first format or the converted data;
The control means includes
3. The image formation according to claim 1, wherein an image determined to have confidentiality by the confidentiality determination unit is controlled to store data in a first format in the storage unit. apparatus. The confidentiality determining means includes
The image forming apparatus according to claim 3 , wherein the image forming apparatus determines whether the information has confidentiality with reference to information included in the data in the first format.   The control means includes
  For the image determined to have no confidentiality by the confidentiality determining means, execute the control for each image,
  For images determined to be confidential by the confidentiality determination means, instead of the control for each image, the amount of data in the first format and the amount of data in the second format are related. 5. The image forming apparatus according to claim 3, wherein the control unit is configured to store the first format data and delete the second format data. 6. The data in the first format is
Data expressed in page description language
The data in the second format is
The image forming apparatus according to any one of claims 1-5, wherein said a first format data which the data have been processed image deployment.

Images