JP2007124074A - Image reading device - Google Patents

Abstract

An object of the present invention is to stop power supply and driving to an analog processor IC that is not used, and a rearrangement circuit rearranges only the output of the analog processor IC to be used, thereby reducing the processing time.
A contact image sensor composed of a plurality of CCD chips, a plurality of analog processor ICs for A / D converting image data read by the contact image sensors, and the plurality of analog processor ICs for output. In an image reading apparatus having a rearrangement circuit for rearranging image data as one line of image data, power supply to an analog processor IC that processes image data outside the document area and driving are stopped according to the document size detection result, and The rearrangement circuit reduces the processing time by rearranging only the analog processor IC output to be driven.
[Selection] Figure 2

Description

  The present invention relates to an image reading technique such as a digital copying machine, a scanner, and a facsimile, and more particularly to an image reading apparatus that reads an image using a contact image sensor including a plurality of CCD chips.

  Conventionally, in this type of image reading apparatus, the method of changing the processing in the apparatus in relation to the original size detection operation is to irradiate only the original area with the light source according to the original size detection result, thereby achieving high resolution and the minimum necessary A technique that enables reading of a document with limited power is known (see Patent Document 1).

In addition, a technique for arbitrarily controlling the optical characteristics of the contact glass according to the size of the document to be read is also known (see Patent Document 2).
JP 2002-247296 A (Page 5, FIGS. 4 and 5) Japanese Patent Laid-Open No. 11-155048 (page 9, FIG. 1)

  In recent years, an image reading apparatus using a contact image sensor is also used in a copying machine for a market that requires high productivity.

  However, in a conventional image reading apparatus using a contact image sensor, an analog processor IC that digitizes each analog output data of a plurality of CCD chips constituting the contact image sensor corresponds to multiple channels, but is unique to the analog processor. There is a problem that the digital data of each CCD chip is output serially at the output timing (order).

  Further, even after the document size is determined, there is a problem that the analog processor IC that processes the corresponding CCD chip output is driven outside the document area.

  The present invention has been made to solve such a problem, and power saving is achieved by stopping power supply and driving to an analog processor IC that processes image data outside the document area based on the document size detection result. It is another object of the present invention to provide an image reading apparatus capable of reducing processing time by rearranging only the output of an analog processor IC to be driven.

  To achieve the above object, the present invention provides a contact image sensor composed of a plurality of CCD chips, a plurality of analog processor ICs for A / D converting image data read by the contact image sensor, and the plurality of the plurality of analog processor ICs. In an image reading apparatus having a rearrangement circuit that rearranges image data output from an analog processor IC as one line of image data, power supply to the analog processor IC that processes image data outside the original area based on the original size detection result, and While the driving is stopped, the rearrangement circuit rearranges only the output of the analog processor IC to be driven, thereby reducing the processing time.

  According to the present invention, it is possible to stop power supply and driving to an analog processor IC that is not used, and the rearrangement circuit rearranges only the output of the analog processor IC to be used. Can be shortened.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a longitudinal sectional view showing a basic configuration of an image reading apparatus according to the present invention.

  The image reading apparatus according to the present invention includes the document feeding device 1 and the document reading device 19, and relatively moves the contact image sensor 13 in the document reading device and the document as a first reading unit. The information on the document is read while relatively moving the contact image sensor unit 20 and the document as a second reading unit. The contact-type image sensor units 13 and 20 are configured by an LED array, a rod lens array, and a contact image sensor which are light sources (not shown).

  The document 3 is set on the document tray 2. The document feed roller 4 is paired with a separation pad 5 and feeds the document 3 one by one. The fed document 3 is further fed into the apparatus by the intermediate roller pair 6, passed to the conveyance by the large roller 8 and the first driven roller 9, and conveyed by the second driven roller 10 in the form of turning around the large roller 8. Is called. The document conveyed by the large roller 8 and the second driven roller 10 passes between the flow reading document glass 12 and the document guide plate 17, and is conveyed again by the large roller 8 and the third driven roller 11 through the jump table 18. . The original 3 is conveyed between the flow-read original glass 12 and the original guide plate 17 in contact with the flow-read original glass 12 by a member of the original guide plate 17.

  Before the document 3 is conveyed, shading is performed by the first and second reading units. The first reading unit reads the reference white plate 22 and the second reading unit reads the white sheet in the update unit 21 of the reference white member, thereby obtaining appropriate white levels.

  When the document 3 passes over the flow-reading original glass 12, the contact image sensor unit 13 exposes the surface in contact with the flow-reading original glass 12 to reflect the original image information reflected from the original 3 (not shown). It is converted as an electrical signal by the image sensor. Through the above process, the first surface (front surface) of the document 3 is read.

  Next, in the process in which the original conveyed by the large roller 8 and the third driven roller 11 is conveyed in the direction of the original discharge roller pair 7, the contact-type image sensor unit 20 moves the second surface (back surface) of the original 3. After reading, it is discharged out of the apparatus.

  FIG. 2 is a diagram for explaining the circuit block configuration of the present invention.

  FIG. 2 illustrates image reading in the document reading device 19. The contact image sensor 306 includes 310 to 320 CCD chips, and outputs analog image data output from each CCD chip to the analog processor ICs 305 and 308. The image data of the CCD chips 310 to 315 is output to the 305 analog processor IC, and the image data of 316 to 320 is output to the 308 analog processor IC.

  The contact image sensor 306 is driven by a drive signal given by the ASIC 304. The analog processor ICs 305 and 308 digitize analog image data output from the contact image sensor, and output the digital image data to the rearrangement circuit 309 in the ASIC 304. The analog processor ICs 305 and 308 are also driven by the drive signal given by the ASIC 304.

  In the rearrangement circuit 309, the image data output at the timing (order) according to the settings of the analog processor ICs 305 and 308 is converted into an image of one line in order from the output of the first CCD chip 310 to the output of the eleventh CCD chip 320. Rearrange to be data. The rearranged image data is subjected to shading correction or the like in the ASIC 304 and is output to the outside of the document reading apparatus.

  The ASIC 304 is connected to the CPU 302 via a bus line or the like, and the CPU 302 is connected to a sub-scanning size detection sensor 307 that detects the document size in the sub-scanning direction, a RAM 303, and the like. The document size in the main scanning direction is detected by the contact image sensor 306.

  FIG. 3 is a diagram for explaining the flow of image data in a normal state.

  The contact image sensor 306 is composed of 11 CCD chips arranged in a line. The output image data from the first CCD chip corresponding to the document abutting side on the document table glass to the eleventh CCD chip corresponding to the front side of the document reading device is set to 1 to 11, respectively. The analog processor IC 305 processes the first to sixth CCD chips, and outputs them in the order of 1 → 3 → 5 → 2 → 4 → 6. Similarly, the analog processor IC 308 processes the seventh to eleventh CCD chips and outputs them in the order of 7 → 9 → 11 → 8 → 10 → X.

  In the rearrangement circuit 309 in the ASIC 304, these analog processor IC outputs are rearranged in order from the first to the eleventh output, and are connected so as to become one line of image data, and then to the next circuit in the ASIC. Send it out.

  FIG. 4 is a diagram for explaining the flow of image data according to the present invention.

  When the document size is within the sensor range from the first CCD chip to the sixth CCD chip corresponding to the document abutting side based on the document size detection result on the document table, only the analog processor IC 305 is used, and 1 → Only the output image data output in the order of 3 → 5 → 2 → 4 → 6 is rearranged in order from the first output to the sixth output in the rearrangement circuit 309. Are connected to each other and sent to the next circuit in the ASIC. At this time, power supply to the analog processor IC 308 that is not used is stopped, and the rearrangement processing in the rearrangement circuit 309 can be performed only for the image data of the six CCD chips output from the analog processor IC 305. , Processing time can be shortened.

  FIG. 5 is a flowchart for explaining the setting process of the present invention.

  First, the document size on the document table is detected (S501). It is determined whether the document area determined based on the document size detection result covers the “sensor range of the first to sixth CCD chips” or the “sensor range of the seventh and subsequent CCD chips” of the contact image sensor 306. (S502).

  If the document area is “the sensor range of the first to sixth CCD chips”, the power supply to the analog processor IC 308 not used is stopped (S503). Subsequently, the rearrangement process in the rearrangement circuit 309 in the ASIC 304 is set to be a process corresponding to only the output of the analog processor IC 305 (S504). Then, the original is read (S505).

  Whether or not the document reading is completed is monitored (S506). When the document reading is completed, the rearrangement circuit setting is returned to the setting corresponding to both the analog processor ICs 305 and 308 (S507). Finally, power supply to the analog processor IC 308 is started and terminated.

  When the document area covers the “sensor range of the seventh and subsequent CCD chips”, normal document reading is performed without performing anything, and the process ends.

  In this embodiment, power supply to the analog processor IC 308 is started in step S508, but power supply to the analog processor IC is stopped except when reading a document or detecting a document size, and when reading a document or detecting a document size. If the document reader is set to supply power, this step is deleted.

  In this embodiment, a contact image sensor composed of 11 CCD chips is used as a document reading means. However, even if the number of CCD chips is any number, a plurality of analog processor ICs can provide CCD chips. It goes without saying that there is no problem as long as the output is processed in parallel.

1 is a schematic sectional view of an image reading apparatus embodying the present invention. It is a figure explaining the circuit block structure of this invention. It is a figure explaining the flow of the image data at the normal time. It is a figure explaining the flow of the image data of this invention. It is a flowchart explaining the setting process of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Document feeder 2 Document tray 3 Document 4 Document feed roller 5 Separation pad 6 Intermediate roller pair 7 Document discharge roller pair 8 Large roller 9 First driven roller 10 Second driven roller 11 Third driven roller 12 Flow-read original Glass 13 Contact-type image sensor unit 17 Document guide plate 18 Jump table 19 Document reader 20 Contact-type image sensor unit 21 Reference white member update unit 302 CPU
303 RAM
304 ASIC
305 Analog processor IC
306 Contact image sensor 307 Sub-scanning size detection sensor 308 Analog processor IC
309 Rearrangement circuit 310-320 CCD chip

Claims (3)

A contact image sensor composed of a plurality of CCD chips, a plurality of analog processor ICs for A / D converting image data read by the contact image sensors, and image data output from the plurality of analog processor ICs as 1 In an image reading apparatus having a rearrangement circuit for rearranging as line image data,
The power supply and driving to the analog processor IC that processes the image data outside the document area are stopped according to the document size detection result, and the rearrangement circuit rearranges only the output of the driven analog processor IC to reduce the processing time. An image reading apparatus characterized by shortening.   The contact image sensor is composed of m lines of CCD chips, and image data output from the first to nth (1 <n <m) CCD chips on the document abutting side is the first analog. The n + 1 th to m th CCD chip outputs are input to the second analog processor IC, and the first analog processor IC performs A / D converted image of the first to n th CCD chips. The data is output at the timing (order) according to the setting of the first analog processor IC, and the second analog processor IC outputs the A / D converted image data of the (n + 1) th to mth CCD chips to the second analog processor IC. Output at the timing (order) according to the setting of the analog processor IC, and the first and second analog processor ICs The output image data is input to the rearrangement circuit, and the rearrangement circuit converts the first to mth image data output at the timing (order) set by the first and second analog processor ICs. 2. The image reading apparatus according to claim 1, wherein the m-th image data is sequentially output from the first image data to the next image processing circuit.   When the document area on the document table is in the range of the first to n-th CCD chips of the contact image sensor, the power supply and driving to the second analog processor IC are stopped, and the first analog processor IC is stopped. In the rearrangement circuit, the image data output from the second analog processor IC is not used, and the image data output from the first analog processor IC is rearranged. 3. The image reading apparatus according to claim 1, wherein only the portion is used and the n-th image data is sequentially output from the first image data to the next-stage image processing circuit.

Images