CN100396082C - Image reading device and image reading method - Google Patents

Abstract

In the image reading device and image reading method of the present invention, a document is placed on the document placement surface of a transparent plate, and the reading performed by the light source on the document is read by a reading device installed on the opposite side of the document placement surface through the transparent plate. Reflected light reflected from the original when illuminated; providing an apparatus capable of preventing disturbing light from affecting the white reference portion provided on the transparent plate side of the positioning member, thereby improving the reading quality. The image reading device includes: a platen glass having an original document placement surface on which an original document is placed; an image sensor disposed on the opposite side of the original document placement surface relative to the platen glass, illuminated by a light source and reads the reflected light; a positioning member and the platen The glass is arranged adjacently to position the original; the white reference part is arranged on the positioning member opposite to the image sensor through the platen glass; and the black reference part is used to absorb disturbing light moving in the platen glass.

Description

Image reading device and image reading method

technical field

The present invention relates to an image reading device and an image reading method, in which an original is placed on an original placement surface of a transparent plate, and an original document irradiated by a light source is read by a reading device provided on the opposite side of the original placement surface through the transparent plate. Instead, reflected light is reflected from the original.

Conventionally, in a known image reading device, a platen made of transparent glass is mounted on the upper surface of a box-shaped frame with an open upper surface, and a contact image sensor (hereinafter Reader such as CIS). In this image reading device, a document is placed on a platen with its reading surface facing down, the image of the document is optically read by the CIS, and the optical signal is converted into an electrical signal to form image data.

In such an image reading device equipped with a CIS, variations in the optical characteristics between light receiving elements and uneven illuminance of each light source lead to large variations in read values, which is not conducive to generation of image information. Therefore, before reading images with CIS, it is necessary to correct the variation between light receiving elements and the unevenness of illuminance of each light source.

Usually, before reading an image by CIS, a white board or a white roller is read with the light source turned off, and the read optical signal is converted into an electrical signal and stored in a buffer memory as black image data. Then, by correcting the image data of the document based on the black image data, it is possible to correct the variation in the optical characteristics between the light receiving elements.

As shown in Patent Document 1, the light source of the CIS is turned on, and the reflected light obtained from a white board or a white roller as a white reference is imaged on a light receiving element and read, and the read optical signal is converted into an electrical signal as White image data is stored in the buffer memory. Then, the image data of the document is corrected based on the white image data. Thereby, it is possible to correct the illuminance unevenness of each light source (see Patent Document 1).

In addition, in the image reading device, in order to cover the pressure plate when reading a document, a document pressure plate can be freely opened and closed in the vertical (up and down) direction. However, when reading a thick original such as a book original, in order to eliminate the shadow of the binding margin, press the back side of the book original from above, and open the original pressure plate relative to the pressure plate, and use the CIS to image. read.

In U.S. Patent No. US2002/0110389, according to the preamble of its technical solution 1, an image forming apparatus is described, which has a transparent document table for placing fixed documents to be scanned and a mobile A separate transparent file reading window through which files are scanned. An indicator for stopping the document is provided above the document table. Below it, a black reference plate and a white reference plate can be seen through the documentation table.

Patent Document 1: JP-A-2000-115473

Patent document 2: US2002/0110389 publication

When image reading is performed with the original platen opened, there is a problem that disturbing light enters the device through the platen. Incidentally, the term "disturbing light" refers to indoor light and outdoor light entering the device from a transparent member such as a platen or an opening of the device. Specifically, the disturbing light entering the device from the pressure plate is reflected and moved inside the pressure plate, and after passing through the pressure plate, it is reflected on the inner surface of the housing or the like. This disturbing light sometimes enters the white board or white roll used as the white reference. When the above-mentioned correction is performed in a state where disturbance light is incident, the output black reference is larger than the original black reference due to the influence of the disturbance light. That is, the black image data is only a part where the disturbance light is incident, and the obtained output is larger than the original black image data. Moreover, due to the influence of interfering light, the output white reference is larger than the original white reference. That is, the white image data is only a part where the disturbance light is incident, and the obtained output is larger than the original white image data.

When the image data obtained by reading the image of the document is corrected using the black image data and white image data affected by the disturbance light, the white of the document becomes significantly darker and is corrected into a dark image. That is, since the output of white in the document not affected by disturbing light is smaller than that of white image data affected by disturbing light, it is corrected to light gray as a brightness lower than the original white, and as a result, no disturbing light is incident The read image in the area of the original becomes dark. In particular, black images with light black levels are destroyed. That is, since the output curve of the CIS slopes gently on the side of the blackness level, and the output difference is small, when the output of the black image data is affected by the disturbance light and becomes larger, the blackness level of the original that is not affected by the disturbance light Output to a dark gray level is less than black image data. As a result, when the image is read after correction, the output from the black level to the dark gray level becomes black.

The influence of such disturbing light, especially in an image reading device including, in addition to the platen, a slit glass for reading a document conveyed by the document conveying device, the upper space of the slit glass is exposed and Easy to get into the problem of interfering light. In detail, the platen has an FBS area as a flatbed scanner (hereinafter referred to as FBS) and an ADF area for reading originals conveyed by an original conveying device such as an automatic document feeder (hereinafter referred to as ADF). When the white reference is set on the original placement surface side of the positioning member in the above area, even if the FBS area is almost covered by the original, the ADF area is still exposed. Therefore, the disturbance light enters the apparatus from the ADF area, and enters the document placement surface side of the positioning member. On the other hand, in the FBS area, since the disturbance light is basically blocked by the document, most of the document is not affected by the disturbance light. Therefore, the above-mentioned problems are liable to arise.

Contents of the invention

Therefore, the present invention relates to an image reading device and an image reading method in which a document is placed on a document placement surface of a transparent plate, and a document read by a light source is read by a reading device provided on the opposite side of the document placement surface through the transparent plate. The purpose of the reflected light irradiated on and reflected from the document is to provide a device that prevents the white reference portion provided on the transparent plate side of the positioning member from being affected by disturbing light, thereby improving the reading quality.

(1) The image reading device of the present invention includes: a transparent plate having an original document placement surface on which an original document is placed; and read the reflected light; drive the reading device to reciprocate along the transparent plate; a positioning element for positioning the original placed on the original placement surface of the transparent plate; the light absorbing part , absorbing the disturbing light incident on the transparent plate side of the positioning element through the transparent plate; and a white reference part, arranged on the transparent plate side of the positioning element; it is characterized in that the transparent plate is a separate transparent plate; The positioning element is arranged at a position where the transparent plate is divided into a plurality of areas, and the plurality of areas divided by the positioning element include a moving original scanning area and a stationary original scanning area, and in the moving original scanning area wherein the reading device reads the original document conveyed by the conveying device for conveying the original document on the upper side of the transparent plate, in this stationary document scanning area, while the reading device moves, the reading device A pickup device reads an original placed on the transparent plate; and the light absorbing portion and the white reference portion are arranged adjacent to the transparent plate side of the positioning member.

A document for image reading is placed on the document placement surface of the transparent plate along the positioning member. While the reading device is being moved by the drive device, the original is illuminated by the light source, and reflected light from the original is read. Image reading of the document is thereby performed. Before performing this image reading, the reading device is moved to positions corresponding to the light absorbing portion and the white reference portion by the driving device. After that, black reference data is acquired on the light-absorbing portion, and white reference data is acquired on the white reference portion, using a reading device. At this time, when a region of the document placement surface on which no document is placed is exposed to the outside, disturbance light enters the device from this region. The disturbing light entering the transparent plate from the outside is reflected inside the transparent plate and enters the transparent plate side of the positioning element, or is reflected on the inner surface of the device main body (casing) by the transparent plate and then enters the transparent plate again. Position the transparent plate side of the component. On the transparent plate side of the positioning element, the light absorbing portion absorbs incident disturbance light. Therefore, when the black reference data is acquired on the light absorbing portion, it is possible to prevent disturbance light from affecting the black reference data. As a result, accurate reference data corresponding to the black color of the document can be acquired, so that when image reading is performed in a state where disturbance light is incident, it is possible to prevent deterioration of the read image.

In addition, according to the present invention, in order to constitute a compact device, the positioning member is provided at the position where the transparent plate is divided into a plurality of regions, and the black reference data is acquired on the light absorbing part for absorbing the disturbing light, so that the disturbing light can be prevented Affects the black reference data.

According to the present invention, when the reading device is moved from the position corresponding to the white reference part to the position corresponding to the light absorbing part, or vice versa, the reading device only needs to move a small distance. Thereby, the interval time between acquisition of white reference data and acquisition of black reference data can be shortened.

According to the present invention, one transparent plate is divided into a plurality of areas, and the above areas are used as scanning areas for moving originals and scanning for stationary originals. A white reference portion and a light absorbing device are provided on the transparent plate side of the positioning device for dividing the regions. In the state where the transparent plate is exposed, disturbance light is incident on the transparent plate side of the positioning device from the moving original scanning area and the stationary original scanning area. In the present invention, since the disturbing light is absorbed by the light absorbing device, the black reference data can be prevented from being affected by the disturbing light by acquiring the black reference data on the light absorbing device for absorbing the disturbing light.

(2) In the image reading device of the present invention, the light absorbing portion is located on the transparent plate side of the positioning member and is provided near the center of the positioning member.

(3) In the above-mentioned image reading device of the present invention, it is characterized in that the reading device reads the original in the moving original scanning area, and the original is moved by the conveying device along the upper part of the transparent plate from the position closer to the positioning element. One side is conveyed to the side farther from the positioning element.

(4) In the above-mentioned image reading device of the present invention, the light absorbing portion is arranged such that the image reading device protrudes from the position where the black reference data is acquired at least toward the side of the moving document conveying area. .

The light absorbing part protrudes from the position where the image reading device acquires the black reference data at least as far as the side of the moving original conveying area, thereby effectively preventing the influence of disturbing light incident from the moving original conveying area.

(5) In the image reading device of the present invention, the length of the light absorbing portion in the main scanning direction is equal to or exceeds the transparent plate; It reciprocates in the sub-scanning direction perpendicular to the main scanning direction.

In the present invention, since the length of the light absorbing portion in the main scanning direction is equal to or exceeds that of the transparent plate, it is possible to sufficiently absorb disturbing light moving inside the transparent plate.

(6) In the above-mentioned image reading device of the present invention, the white reference part is arranged on the moving original scanning area side with respect to the light absorbing part, and is arranged on the moving original scanning area side with respect to the white reference part. A second light absorbing portion is arranged.

Disturbing light incident from the side of the moving document conveyance area can be absorbed by the second light absorbing portion.

(7) In the image reading apparatus of the present invention, a part of the white reference part is covered with the light absorbing part so as to provide a gap between the white reference part and the light absorbing part in the vicinity of the scanning area of the moving document. a boundary extending along the main scanning direction of the reading device, and two borders extending along the sub scanning direction of the reading device between the white reference part and the light absorbing part are provided near the fixed scanning area boundaries.

(8) In the above-mentioned image reading device of the present invention, the length of the white reference part in the main scanning direction is equal to or exceeds the length of the transparent plate; A belt is attached to the transparent plate at the edge adjoining the scanning area of the moving original.

(9) In the image reading device of the present invention, the third light-absorbing portion is provided on an inner surface of the device main body.

Due to the third light absorbing portion, it is possible to absorb disturbing light that has passed through the transparent plate and reaches the inside of the device main body.

(10) In the image reading device of the present invention, the light-absorbing portion, the second light-absorbing portion, and the third light-absorbing portion are substantially black.

In the present invention, since the light absorbing part, the second light absorbing part and the third light absorbing part are substantially black, disturbance light can be sufficiently absorbed.

(11) In the above-mentioned image reading device of the present invention, it is characterized in that it further includes a control device for controlling the reading device and the driving device; the control device enables the reading device to read Acquiring white reference data in the white reference area of the white reference part; and enabling the reading device to acquire black reference data in the light absorbing part area where the light absorbing part can be read with the light source turned off.

According to the present invention, since the white reference data is obtained at a plurality of positions of the white reference part by moving the reading device, for example, even if dust is attached to a part of the white reference part, the influence of this part is small, so that the brightness can be accurately determined. output correction. Also, since the black reference data is acquired by aligning the position of the reading device with the light absorbing portion that absorbs the disturbance light, accurate black reference data can be acquired.

(12) In the image reading device of the present invention, the control device moves the reading device along the sub-scanning direction within the white reference area, and moves the reading device at a plurality of positions within the white reference area. Acquiring white reference data; the plurality of positions are mutually different positions in a sub-scanning direction, and each position is a position extending in a main scanning direction perpendicular to the sub-scanning direction of the reading device.

(13) In the image reading device of the present invention, the control device causes the reading device to reciprocate within the white reference area, and reads the white reference area by the reading device. data.

According to the present invention, when acquiring white reference data, since the reading device is reciprocated to acquire white reference data at a plurality of positions on the white reference portion, for example, even if dust adheres to a part of the white reference portion, The influence of this part can be reduced, so that brightness output correction can be accurately performed.

(14) In the image reading device of the present invention, when acquiring the black reference data, the control device stops the reading device, and acquires a plurality of black reference data at regular intervals.

According to the present invention, since the reading device acquires a plurality of black reference data, dark output correction can be accurately performed without being affected by variations in the black reference data.

(15) In the above-mentioned image reading device of the present invention, the control device moves the reading device from a predetermined standby position to the light-absorbing portion region to acquire black reference data, and then makes the The reading device moves to the white reference area to acquire white reference data.

According to the present invention, since the black reference data is acquired first and then the white reference data is acquired, the reading device can easily perform the correction process.

(16) In the image reading device of the present invention, the control device moves the reading device from a standby position closer to the white reference area than the light absorbing portion area to the white reference area to acquire White reference data, then, further moving the reading device to the light absorbing portion area to acquire black reference data.

According to the present invention, when the reading device performs calibration, since the reading device moves in the same direction from the standby position through the white reference area to the light absorbing portion area, the movement of the reading device only needs to be short. Therefore, the time required for correction can be shortened.

(17) In the image reading device of the present invention, the control device moves the reading device from the standby position to the white reference area, and adjusts the light quantity of the light source. Adjust to obtain white reference data.

According to the present invention, the brightness output correction can be accurately performed by turning on the light source with the adjusted light quantity and acquiring white reference data.

(18) In the image reading device of the present invention, the control device holds already acquired black reference data, and adjusts the light intensity of the light source based on the black reference data when performing the light intensity adjustment.

The amount of light is adjusted in the white reference area so that the output of the white reference data relative to the black reference data becomes a desired value. On the other hand, the control device moves the reading device from a standby position closer to the white reference region than the light-absorbing portion region to the white reference region to obtain white reference data, and moves over the light-absorbing portion region to obtain black reference data. Therefore, when the light amount adjustment of the reading device is performed on the white reference area,

(19) In the above-mentioned image reading device of the present invention, the control device controls the The light source turns off.

According to the present invention, the light source is turned off while the reading device is moved from the white reference region to the light absorbing portion region. Therefore, dark output correction can be performed immediately when the reading device reaches the light absorbing portion region.

(20) The image reading method of the present invention, using the image reading device described above, includes: a step of acquiring white reference data in which the reading device is positioned within the white reference area where the white reference portion can be read. moving, and causing the reading device to acquire white reference data at a plurality of positions of the white reference part in a state where the white reference part is irradiated with the light source; and a black reference data acquisition process, causing the The reading device stops within the white reference area or below the light absorbing portion, and acquires black reference data at regular intervals while the light source is turned off.

According to the present invention, since the light absorbing portion absorbs the disturbing light, the disturbing light does not enter the reading device from the light absorbing portion. Therefore, by causing the reading device to read the light-absorbing portion with the light source turned off, black reference data rich in gradation can be acquired, and dark output correction can be accurately performed.

(21) The image reading method of the present invention, which uses the image reading device described above, includes: a step of acquiring black reference data, in which the reading device is moved from a predetermined standby position to a position where the light absorption can be read. the light-absorbing portion region of the light-absorbing portion for which black reference data is acquired with the light source turned off; The white reference area of the above-mentioned white reference part is used, and the white reference data is acquired for the white reference area.

In the black reference data acquisition step, the reader is moved from a predetermined standby position to the light absorbing portion region where the light absorbing portion can be read, and black reference data is acquired with the light source turned off in the light absorbing portion region. Since the disturbing light incident on the light absorbing portion can be absorbed, the disturbing light does not enter the reading device. Furthermore, since the light source is turned off, light other than disturbance light does not enter the light absorbing portion. Therefore, the reading device can obtain black reference data without absorbing reflected light at all. Thereby, accurate dark output correction can be realized. In this way, since accurate output correction corresponding to the black color of the document can be realized, when image reading is performed in a state where disturbance light is incident, it is possible to prevent deterioration of the image quality of the read image.

(22) The image reading method of the present invention, using the image reading device described above, includes: a standby step of placing the reading device at a standby position closer to the white reference portion than the light absorbing portion. Standby; a white reference data acquisition process in which the reading device moves from the standby position to a white reference area where the white reference portion can be read, and acquires white reference data for the white reference area; and a black reference data acquisition process, The reading device is moved from the white reference area to a light absorbing portion area where the light absorbing portion can be read, and black reference data is acquired with the light source turned off for the light absorbing portion area.

In the standby step, the reading device is kept on standby at a standby position closer to the white reference portion than the light absorbing portion. The light absorbing portion is located on the transparent plate side of the positioning member, and is disposed near the center in the moving direction of the reading device. Also, a white reference portion is provided on the transparent plate side of the positioning member. That is, the white reference part is arranged on either side of the moving direction of the reading device with respect to the light absorbing part. If the standby position is on the side where the white reference part is disposed with respect to the light absorbing part, it may be an area on the side where the original document is placed, or an area on the other side where no original document is placed.

In the white reference data acquisition step, the reading device is moved from the standby position to the white reference area where the white reference portion can be read, and the white reference data is acquired on the white reference area. When the reading device moves from the standby position to the position corresponding to the positioning element, it reaches the white reference area before reaching the light absorbing portion area. Therefore, the white reference data for the white reference area can be obtained before the black reference data is obtained, which is effective.

In the black reference data acquisition step, the reading device is moved from the white reference area to the light absorbing portion area where the light absorbing portion can be read, and black reference data is acquired with the light source turned off for the light absorbing portion area. The path of the reading device moving from the standby position through the white reference area to the light absorber area is unidirectional. Therefore, the reading device can be moved quickly and smoothly. Furthermore, since the disturbing light incident on the light absorbing part can be absorbed, it will not be reflected on the reading device. Furthermore, since the light source is turned off, light other than disturbance light does not enter the light absorbing portion. Therefore, the reading device can obtain black reference data in a state where no reflected light is absorbed at all. Thus, accurate and rapid dark output correction can be realized. In this way, accurate and rapid output correction corresponding to the white and black of the document can be realized, so that when image reading is performed with incident light incident, it is possible to prevent deterioration of the image quality of the read image.

(23) In the above-mentioned image reading method of the present invention, in the step of acquiring white reference data, before acquiring white reference data for the white reference area, the white reference area is scanned by the reading device. Adjustment of the light intensity of the light source.

In the white reference acquiring step, when the reading device moves from the standby position onto the white reference area, the light intensity of the light source of the reading device may be adjusted. The amount of light is adjusted so that the white reference data of the white reference obtained for the white reference area becomes a desired output. Thereby, the light source of the reading device can be adjusted to a desired amount of light. Thereafter, by turning on the light source at the adjusted light intensity to obtain white reference data, accurate brightness output correction can be performed.

(24) In the image reading method of the present invention, in the white reference data acquisition step, the light intensity of the light source is adjusted based on already acquired black reference data.

In order to make the output of the white reference data with respect to the black reference data a desired value, the light intensity of the white reference area is adjusted. On the other hand, first, the reading device is moved from the standby position to the white reference area. Therefore, when the light intensity adjustment of the reading device is performed in the white reference area, although the black reference data has not yet been acquired, the acquired black reference data is kept, and the light intensity adjustment of the light source is performed based on the black reference data. Accurate light volume adjustments were possible before.

(25) In the image reading method of the present invention, in the black reference data acquisition step, while the reading device is moved from the white reference area to the light absorbing part area, Turn off the light source.

While moving the reading device from the white reference region to the light absorbing portion region, the light source is turned off. As a result, the black reference data can be acquired immediately after the reader reaches the light-absorbing portion region.

Description of drawings

Fig. 1 (a) is a perspective view showing the structure of the image reading device 1 in a state where the main body cover 5 is closed, and Fig. 1 (b) is a perspective view showing the structure of the image reading device 1 in a state where the main body cover 5 is opened;

2 is a plan view showing the upper structure of the device main body 3 on the image reading device 1;

3 is a schematic cross-sectional view showing a cross-sectional structure along the longitudinal direction of the image reading device 1;

FIG. 4 is a block diagram showing the electrical configuration of the image reading device 1;

Fig. 5 (a) is the plan view that represents the structure of the lower surface of positioning member 17, and Fig. 5 (b) is the sectional view that represents along A-A section;

FIG. 6 is a flowchart showing image reading processing performed by the image reading device 1;

FIG. 7 is an explanatory diagram showing light amount adjustment and shadow data calculation processing performed by the image reading device 1;

FIG. 8 is an explanatory diagram showing light amount adjustment and shadow data calculation processing performed by the image reading device 1;

FIG. 9 is an explanatory view showing the peripheral structure of the platen glass 13 of the image reading device 1.

FIG. 10 is an explanatory diagram showing the operation of the image sensor 21 when performing light amount adjustment and shadow data calculation processing;

FIG. 11 is an explanatory diagram showing the operation of the image sensor 21 when performing light amount adjustment and shadow data calculation processing;

12 is an explanatory view showing the peripheral structure of the platen glass 13 of the image reading device 1;

FIG. 13 is an explanatory diagram showing light amount adjustment and shadow data calculation processing performed by the image reading device 1 .

specific embodiment

Next, an example (embodiment) of the image reading device and image reading method of the present invention will be described.

Example 1

(a) First, the overall configuration of the image reading device 1 according to the first embodiment will be described with reference to FIGS. 1 to 3 .

The image reading device 1 of the first embodiment constitutes a flatbed scanning device, and a main body cover 5 is provided above the device main body 3 so as to be openable. The device main body 3 is formed in a box shape with an open upper surface, and an image sensor (reading device, CIS) 21 is disposed therein so as to be reciprocable in a sub-scanning direction (left-right direction in FIG. 3 ). And the platen glass (transparent plate) 13 is fixed to the opening part of the upper cover of the apparatus main body 3 with the double-sided tape. The platen glass 13 is made of transparent glass or resin, and its upper surface constitutes a document placement surface on which a document is placed.

In addition, although the image reading apparatus 1 can be used, for example, as a part of a multifunctional machine including a scanner function, a printer function, and a facsimile function, in the present invention, functions other than the scanner function are optional, and of course Can be used as a single scanner.

On the upper surface of the device main body 3, a platen glass 13 made of a single piece of glass is installed, and the upper surface of the platen glass 13 can be covered by a main body cover 5, wherein the main body cover 5 can be covered with the back side of the device (in FIG. 2 ). The upper side) is the fulcrum to open and close in the up and down direction. A document conveyance device (conveyor) 40 is attached to one end of the main body cover 5 and can cover the platen glass 13 together with the main body cover 5 . Further, on the lower surface of the main body cover 5 , a pressing member made of a sponge, a white board, or the like is provided at a position facing the platen glass 13 . The document placed on the platen glass 13 is pressed by this pressing member. In addition, Fig.1 (a) has shown the state which closed the main body cover 5 and covered the platen glass 13. FIG. 1( b ) shows a state in which the main body cover 5 is opened and the entire platen glass 13 is exposed.

An operation unit 15 including various switches such as numeric keys and an LCD panel is provided on the front side (lower side in FIG. 2 ) of the device main body 3 . Commands input by operating the keys of the operation unit 15 are executed by the CPU 101 described below. Also, the image reading device 1 may be connected to an external information device such as a computer, and the CPU 101 executes commands issued by software such as a scanner driver installed on the computer or the like.

An opening is formed on the upper surface of the upper cover of the apparatus main body 3, and the platen glass 13 is attached to the opening. Further, an image sensor 21 reciprocally movable in a sub-scanning direction (left-right direction in FIG. 3 ) is provided in the internal space of the apparatus main body 3 . The position of the image sensor 21 is below the platen glass 13 . On the other hand, the document placement surface is the upper surface of the platen glass 13 . In other words, the position of the image sensor 21 is located on the opposite side of the original document placement surface with respect to the platen glass 13 .

The image sensor 21 is a contact-type reading sensor, and includes a point light source such as an LED (hereinafter referred to as a light source), and is composed of three colors of R, G, and B for illuminating the original on the platen glass 13; A lens for collecting reflected light from the document P; and a plurality of light receiving elements arranged upwardly in a row at predetermined intervals. The array length of the light receiving elements of the image sensor 21 is substantially the same as the length of the platen glass 13 .

There is a driving device inside the device main body 3, and the driving device includes: a DC motor 23, which is arranged at one end in the longitudinal direction (sub-scanning direction) of the device main body 3, so that the motor shaft is positioned below; a pulley 25a mounted on the motor shaft ; and the endless belt 25b stretched between the pulleys 25a. With this drive device, the image sensor 21 can be moved in the sub-scanning direction (device length direction). Thus, as will be described later, the image sensor 21 is configured to reciprocate between the stationary document scanning area (first reading unit) 11 and the moving document scanning area (second reading unit) 12 of the platen glass 13 .

On the document placement surface side of the platen glass 13, a positioning member 17 (positioning member) is provided. The positioning member 17 is used to divide the document placement surface of the platen glass 13 into a plurality of areas, specifically, a stationary document scanning area 11 and a moving document scanning area 12 . When the image reading apparatus 1 is used as the FBS, the stationary original scanning area 11 is a surface for placing the original P, and when the original conveying device 40 is used, the moving original scanning area 12 is a surface for reading the conveyed original P. surface. As shown in FIG. 2 , the platen glass 13 is divided into two regions by the positioning member 17 so that a narrow predetermined region is formed on the left side in the sub-scanning direction of the device (left-right direction in FIG. A predetermined area with a wide width of the document P of the largest size that can be read is placed. The narrow area on the left is the stationary document scanning area 11 , and the wide area on the right is the moving document scanning area 12 .

When the image reading apparatus 1 is used as the FBS, the read original P is placed on the platen glass 13 facing down in the state of FIG. 1( b ). More specifically, the original P is placed on the stationary original scanning area 11 of the platen glass 13 with the reading side facing down, using the positioning member 17 as an end reference of the original P. Then, as shown in FIG. 1( a ), the main body cover 5 is rotated downward about the fulcrum again, and the original P is pressed from above to perform image reading on the original P. When reading the original P, as shown in FIG. 3(b), the image sensor 21 installed on the endless belt 25b is moved to the right in FIG. The reflected light is imaged on the light-receiving element through the lens, and the optical signal is converted into an electrical signal.

As shown in FIG. 3 , a document feeder 40 (ADF) is mounted on the main body cover 5 . The document conveying device 40 includes: a paper feed tray 41, on which the originals P are placed with the reading surface facing down; and a paper output tray 42, which is arranged above the paper feeding tray 41, and stacks the read documents P with the reading surface facing up. The document P; and the transport path 55 form a U-turn shape from below between the paper feed tray 41 and the paper output tray 42 . The paper feed tray 41 and the paper output tray 42 are arranged to be offset in the horizontal direction so that the upper space of the paper feed tray 41 is open. Therefore, there is an advantage that it is easier to set the document P on the paper feed tray 41 than when the paper output tray 42 is disposed directly above the paper feed tray 41 . In addition, with the paper feed tray 41 and the paper output tray 42 , the originals P before and after reading can be held separately on the paper feed tray 41 or the paper output tray 42 .

The originals P stacked on the paper feed tray 41 are sent out by paper feed rollers 44 and 45 disposed below the paper feed tray 41 , separated one by one, and conveyed to the downstream side of the transport path 55 . On the downstream side of the feed rollers 44 , 45 , transport rollers 47 , 48 constituted by roller pairs are arranged, whereby the document P can be transported to the moving document scanning area 12 at the lowermost position. On the moving document scanning area 12 of the platen glass 13, an upper plate 49 is arranged facing each other at a predetermined interval. The conveyed document P is sequentially read by the image sensor 21 standing by in the moving document scanning area 12 (ADF reading position). At one end of the platen glass 13 (left end in FIG. 3 ), a scoop member for deflecting the front end of the document P moving on the platen glass 13 is provided. Then, it is sent out by being reversed upward by a pair of transport rollers 51 and 52 , and is discharged to the paper output tray 42 with the reading surface facing upward by the discharge rollers 53 and 54 .

The structure of the conveying device 40 described above is only an example. For example, it is obvious that the positional relationship between the paper feed tray 41 and the paper output tray 42 can be changed, or the rollers such as the paper feed rollers 44, 45, the conveying rollers 47, 48, and the discharge rollers 53, 54 can be changed. The structure and configuration of the transmission device 40, or changing the transmission path 55, etc., changes the structure of the transmission device 40 to the structure of other known transmission devices.

(b) Next, the configuration of the positioning member 17 will be described with reference to FIG. 5 . In addition, FIG. 5( a ) is a diagram showing the lower surface (glass abutting surface) of the positioning member 17 , and the up-down direction in FIG. 5( a ) is the main scanning direction, which corresponds to the up-down direction in FIG. 2 . And the left direction in FIG. 5( a ) is the left direction in FIG. 2 . Therefore, in FIG. 5( a ), the left side of the positioning member 17 is the moving document reading area 12 , and the right side of the positioning member 17 is the stationary document reading area 11 . In addition, Fig. 5(b) is a sectional view along the A-A section in Fig. 5(a).

The positioning member 17 is a substantially rectangular plate member whose length in the main scanning direction (ie, the up-down direction in FIG. 5( a )) is the same as that of the platen glass 13 in the main scanning direction. Therefore, when the positioning member 17 is arranged on the upper surface of the platen glass 13 along the main scanning direction as shown in FIG.

The entire lower surface of the positioning member 17 is covered with the white reference part 17a which is a white sheet member. Further, a black reference portion (light absorbing portion) 17b that is a black thin plate member is attached to the lower surface of the white reference portion 17a. The black reference portion 17b is arranged such that about 1/3 of the area from the left end of the white reference portion 17a is uncovered and exposed. In other words, approximately 1/3 of the moving document scanning area 12 side and approximately 2/3 of the right side (stationary document scanning area 11 ) of the white reference portion 17a are covered by the black reference portion 17b.

The exposed part of the white reference part 17a which is not covered by the black reference part 17b is used for acquiring white reference data and adjusting the light intensity described later. Furthermore, the center of about 1/3 of the area of the black reference part 17b is cut away, and the white reference part 17a is exposed. The line at the left end 17 f of the black reference portion 17 b , that is, the boundary between the white reference portion 17 a and the black reference portion 17 b serves as a reference position for sub-scanning by the image sensor 21 . That is, the HP (standby position) at the time of power-on initialization and after reading is determined from the left end 17f.

On the right side of the black reference portion 17b, two boundaries in the main scanning direction between the white reference portion 17a and the black reference portion 17b formed by cutting out the central portion serve as the main scanning reference position 17d of the image sensor 21 . In addition, in the image reading device 1 of the first embodiment, the center of the two reference positions 17d is determined as the center of the document P. As shown in FIG. At such reference positions 17d and 17f, the color (brightness) changes significantly due to the white of the white reference portion 17a and the black of the black reference portion 17b, so it can be clearly determined from the output of the image sensor 21 .

The part of the black reference part 17b connected to the main scanning direction of the image sensor 21, in other words, the part corresponding to the center of the image sensor 21 of the positioning member 17 in the sub scanning direction, is used to acquire black reference data described later. Acquisition of the black reference data is not performed over the entire area of the black reference portion 17b in the sub-scanning direction, but is performed at the position 17h corresponding to the main scanning line where the light receiving elements of the image sensor 21 are arranged. . The width of the black reference part 17b near the center is very wide relative to the position 17h where the black reference data is acquired, and the black reference part 17b protrudes from at least the position 17h to the left, that is, the moving document scanning area 12 side. Of course, the black reference portion 17b may protrude from the position 17h to the right side (stationary document scanning area 11).

On the right end area in the lower surface of the positioning member 17, a transparent double-sided tape 17c is attached. This double-sided tape 17c comprises: a thicker double-sided tape 17c1, attached near the center of the up-down direction in Fig. 5 (a); and a thinner double-sided tape 17c2, attached to the upper end and near the lower end. The thickness difference of the said double-sided tape 17c1, 17c2 corresponds to the thickness difference of the white reference part 17a and the black reference part 17b. At the position where the double-sided tape 17c1 is attached, the white reference part 17a is cut out according to the shape of the double-sided tape 17c1, and the double-sided tape 17c1 is directly attached to the positioning member 17. On the other hand, the double-sided tape 17c2 is laminated on the white reference part 17a and the black reference part 17b.

The left end of the white reference part 17a protrudes to the left side of the positioning member 17, and a transparent tape 17e is attached to the upper surface of the protruding part. The right end of the transparent tape 17e is fixed to the positioning member 17, and the left end protrudes to the left side of the white reference portion 17a.

As described above, the white reference portion 17a and the black reference portion 17b are arranged on the lower surface of the positioning member 17, and the positioning member 17 is closely attached to the upper surface of the platen glass 13 through the double-sided tapes 17c1, 17c2 and the tape 17e. Above, that is, the white reference portion 17 a and the black reference portion 17 b are disposed on the transparent plate side of the positioning member 17 . Thus, the white reference portion 17a is arranged on the side of the moving original scanning area 12 on the transparent plate side of the positioning member 17, and the black reference portion 17b is arranged on the side of the sub-scanning direction of the image sensor 21 on the transparent plate side of the positioning member 17. central.

(c) Next, the electrical configuration of the image reading device 1 will be described using the block diagram of FIG. 4 .

The CPU 101 controls each part of the image reading device 1 according to the control program stored in the ROM 102, for example, controls the forward and reverse rotation of the motor 23, performs speed control, and controls the light source included in the image sensor 21 to turn on/off the light. wait.

ROM 102 stores programs for controlling image reading device 1 . RAM 103 is used to temporarily store image data read by image sensor 21 and image data from a PC connected to image reading device 1 . The RAM 103 has at least a black reference buffer area 103a for storing black reference data for correcting gradation characteristics between light receiving elements, and a white reference buffer area 103b for storing white reference data for correcting light intensity variations of point light sources.

The correction circuit 104 performs processing such as black correction, white correction, and γ correction on the colors R, G, and B row by row, respectively. That is, various corrections such as shading correction are performed on the image of the document P read by the image sensor 21 .

The image processing section 106 performs processing such as smoothing and emphasizing the corrected image data, converting RGB data into CMYK (cyan-magenta-yellow-black) data that can print RGB data, and the like.

(d) Next, the processing performed by the CPU 101 of the image reading device 1 will be described with reference to FIGS. 6 to 10 .

First, an overview of processing executed by the CPU 101 will be described using the flowchart of FIG. 6 .

In step 100, the CPU performs light quantity adjustment and shadow data calculation. This processing will be described in detail below.

Next, in step 110 , CPU 101 reads document P and generates an image signal. Among them, the original P placed on the stationary original scanning area 11 of the platen glass 13 is read as described below. The CPU 101 controls the motor 23 and at the same time reads the document P placed on the stationary document scanning area 11 on the image sensor 21 . That is, the CPU 101 moves the image sensor 21 in the sub-scanning direction by means of the drive device, and reads the document P placed on the stationary document scanning area 11 on the image sensor 21 .

The document P conveyed by the document conveying device 40 is read as follows. CPU 101 fixes image sensor 21 below moving document scanning area 12 . Then, the CPU 101 controls the original conveying device 40 to convey the originals P placed on the paper feed tray 41 one by one to the moving original scanning area 12 . When the document P passes through the moving document scanning area 12 , the document P is read by the image sensor 21 .

The image signal output from the image sensor 21 that reads the document P is digitized by an internal circuit, and the digital image signal is generated by the correction circuit 104 as described later, or known shading correction is performed based on the updated shading data. The shading-corrected image signal is stored in RAM 103 , and is supplied to an image forming apparatus integrally equipped with an external information device, ie, a computer, as a multifunction peripheral via interface 105 by the operation of CPU 101 .

Next, processing of light amount adjustment and shadow data calculation performed by the CPU 101 will be described with reference to FIGS. 7 , 9 and 10 . In addition, FIG. 7 is a flowchart showing light amount adjustment and shadow data calculation processing, and FIGS. 9 and 10 are explanatory diagrams showing the position of the image sensor 21 in the above processing.

One of light adjustment and shadow data calculation processing

Before starting the process, the image sensor 21 is at the home position (HP, standby position). This HP is a standby position closer to the white reference portion 17a than the black reference portion 17b (see FIG. 10 ). This standby position is determined based on the reference position 17f in the sub-scanning direction shown in FIG. 5 . That is, when the power is turned on, the CPU 101 moves the image sensor 21 below the positioning member 17 with the light source turned off to read the reference position 17f. The reference position 17f is the boundary between white and black. Since the output of the light receiving element changes with the change of the reflected light, the CPU 101 determines the reference position 17f based on the change in the output of the image sensor 21 . The side where the white reference portion 17a is exposed from the reference position 17f, that is, the position where the image sensor 21 is moved by a certain distance on the moving document scanning area 12 is defined as a standby position (standby process). In addition, it is preferable to make the standby position near the positioning member 17 from the viewpoint of speeding up the adjustment of the light intensity and the acquisition of correction data.

In step 200 of FIG. 7 , when the start button of the operation unit 15 is pressed, the motor 23 is rotated by a command from the CPU 101 , and the image sensor 21 starts moving in order to acquire black reference data and white reference data. The image sensor 21 stops below the black reference portion 17 b after leaving the initial position HP by a certain distance (movement from (1) HP to (2) black reference portion in FIG. 10 ). As shown in FIG. 9( b ), the moved image sensor 21 is located below the black reference portion 17 b (light absorbing portion region).

In step 210 (black reference data acquisition step), black reference data is acquired. Specifically, the black reference portion 17b is read a plurality of times while the light source of the image sensor 21 is turned off. Then, in order to average the obtained data, it is divided by the number of readings for each light-receiving element, and stored as black reference data in the black reference buffer area 103 a of the RAM 103 .

In step 220, after setting the black reference data, the CPU 101 drives the motor 23 again, so that the image sensor 21 is moved from the black reference portion 17b to below the white reference portion 17a (the white reference area) (from (2) in FIG. Movement of the black reference part to (3) the white reference part).

In step 230, light quantity adjustment is performed on the white reference part 17a. Specifically, first, the light source of the image sensor 21 illuminates the white reference portion 17a with a sufficiently small amount of light, and the reflected light is read by the light receiving element. If the light quantity of the light source is small, the output of the light receiving element is small. Then, the light quantity of the light source is increased stepwise or continuously until the output of the light receiving element reaches a desired value, and the light quantity of the light source when the output of the light receiving element reaches the desired value is stored in RAM 103 as a light quantity adjustment value. In addition, the desired output of the light receiving element is set so that the output of the white reference data relative to the black reference data becomes a desired value.

In step 240 (in a white reference data acquisition step), the image sensor 21 is caused to read the white reference portion 17a. Specifically, the light source of the image sensor 21 emits light at the light amount adjustment value, and the light reflected by the white reference portion 17a is read by the light receiving element. The white reference data is thereby obtained. When acquiring the white reference data, the CPU 101 rotates the motor 23 forward and reverse to reciprocate the image sensor 21 under the white reference portion 17a. The range of reciprocating movement is between point A and point B, wherein point A corresponds to a position 1 mm from the left end of the white reference portion 17a, and point B corresponds to a position 1 mm from the right end of the white reference portion 17a (see (3 in FIG. 10 ). ) part of the white reference part). During this reciprocating movement, the light receiving element is made to acquire a plurality of data at different positions on the white reference portion 17a. And, in order to average the obtained data, it is divided by the number of times of reading for each light receiving element, and is stored in the white reference buffer area 103 b of the RAM 103 as white reference data.

In step 250 , CPU 101 generates black shading data using the black reference data acquired in step 210 described above, and generates white shading data using the white reference data acquired in step 240 described above. The generated shading data for each color is stored in RAM 103 .

In addition, the generated shading data for each color is used for shading correction of the image signal. The generated shadow data for each color is updated on every regeneration.

In step 260, CPU 101 moves image sensor 21 to the reading start position. When reading a document conveyed by the document conveying device 40 , the reading start position is the ADF reading position shown in FIG. 3( a ). When reading a document placed on the stationary document reading area 11, it is located below the left end of the stationary document reading area 11 as shown in FIG. . Then, as described above, the original P is illuminated with light from the light source of the image sensor 21, and the reflected light is read by the light receiving element, whereby the image of the original P is read.

(e) Next, the effects achieved by the image reading device 1 and the reading method of the first embodiment will be described.

i) The image reading device 1 of the first embodiment acquires black reference data in a state where the image sensor 21 is located under the black reference portion 17b. The black reference portion 17 b is located on the document placement surface (lower surface) side of the positioning member 17 . Therefore, when image reading is instructed with the main body cover 5 opened, and both sides, that is, the stationary document scanning area 11 and the moving document scanning area 12 are exposed, disturbance light may enter. In particular, when the image reading device 1 is used as the FBS to read a thick original, it is difficult for the main body cover 5 to be completely closed, and since the original P is not placed on the moving original scanning area 12, disturbance light is likely to enter. The disturbance light incident on the transparent plate side of the positioning member 17 in this way is absorbed by the black reference portion 17b. As a result, disturbance light incident on the black reference portion 17 b is not reflected on the image sensor 21 . Furthermore, by turning off the light source of the image sensor 21 and acquiring black reference data for the black reference portion 17b, accurate black reference data can be obtained without being affected by disturbance light. Therefore, in the image reading device 1 of the first embodiment, black reference data rich in gradation can be acquired, and shading correction can be accurately performed.

ii) In Embodiment 1, the white reference portion 17a and the black reference portion 17b are disposed on the document placement surface (lower surface) side of the positioning member 17, and the positioning member 17 is disposed on the document placement surface (upper surface) of the platen glass 13. on the surface). Therefore, the white reference portion 17 a and the black reference portion 17 b are arranged on the document placement surface (upper surface) of the platen glass 13 .

Accordingly, the distance from the image sensor 21 to the white reference portion 17 a and the distance from the image sensor 21 to the black reference portion 17 b are equal to the distance from the image sensor 21 to the document P placed on the platen glass 13 . In other words, the white reference data obtained for the white reference portion 17 and the black reference data obtained for the black reference portion 17 b are the same as the conditions for obtaining the image data of the document P. FIG. Thus, the reading device 1 of the first embodiment can accurately acquire white reference data by using the white reference unit 17 and accurately acquire black reference data by using the black reference unit 17b.

iii) In Embodiment 1, as shown in FIG. 5, since the white reference portion 17a and the black reference portion 17b are arranged adjacent to each other along the sub-scanning direction of the image sensor 21, when the image sensor 21 is positioned from below the white reference portion 17a, When moving to the lower side of the black reference portion 17b or in the opposite direction, the moving distance of the image sensor 21 may be relatively small. Thereby, the interval time between acquisition of white reference data and acquisition of black reference data can be shortened. Therefore, shadow data can be generated in a short time.

iv) In the first embodiment, as shown in FIG. 5 , the black reference portion 17b is arranged to protrude from the center of the image sensor 21 of the positioning member 17 in the sub-scanning direction to the side of the moving document scanning area 12 . Thereby, from the position 17h where the black reference data is acquired, a sufficient area of the black reference portion 17b can be secured with respect to the moving document scanning area 12 side where disturbance light is likely to enter. Therefore, the incident light enters from the moving scanning area 12, is reflected in the platen glass 13, or is reflected into the frame through the platen glass 13, enters the transparent plate side of the positioning member 17, and can be reliably absorbed by the black reference portion 17b.

v) In Embodiment 1, the length of the black reference portion 17b in the main scanning direction is greater than the length of the platen glass 13 in the main scanning direction, and the black reference portion 17b extends from one end of the platen glass 13 to the other end. Therefore, the black reference part 17b can fully absorb the disturbance light which moves in the platen glass 13. As shown in FIG.

vi) In Embodiment 1, since the image sensor 21 is reciprocated and the white reference data is acquired at a plurality of positions of the white reference part 17a, even if dust adheres to a part of the white reference part 17a, the part can be subtracted. Small influence, so white reference data can be acquired accurately.

vii) In Embodiment 1, since the image sensor 21 acquires a plurality of black reference data, it is possible to accurately acquire the black reference data without being affected by variations in the black reference data.

viii) In Embodiment 1, when one of the processing methods of light quantity adjustment and shadow data calculation processing (refer to FIG. 7 ) is used, since the black reference data is obtained first, and then the white reference data is obtained, the light quantity adjustment is easy.

Light adjustment and shadow data calculation processing part two

In the first embodiment, the processing of light quantity adjustment and shadow data calculation can be performed as follows. This processing will be described using FIGS. 8 , 9 and 11 . In addition, FIG. 8 is a flowchart showing light amount adjustment and shading data calculation processing, and FIGS. 9 and 11 are explanatory diagrams showing positions of image sensors in the above processing.

Before starting the process, the image sensor 21 is at the home position (HP). The method of putting the image sensor 21 on standby at the standby position (standby step) is the same as above. In step 300 of FIG. 8 , when the start button of the operation unit 15 is pressed, the motor 23 is rotated by a command from the CPU 101 , and the image sensor 21 starts to move from HP to acquire black reference data and white reference data. The image sensor 21 moves a certain distance from the HP, and stops below the white reference portion 17a (white reference area). (Movement from (1) HP to (2) white reference portion in FIG. 11 ). As shown in FIG. 9( a ), the moved image sensor 21 is located below the white reference portion 17 .

In step 310 , CPU 101 adjusts the light intensity of the light source of image sensor 21 to a light intensity suitable for reading white reference data. Although this light quantity adjustment is the same as the light quantity adjustment shown in step 230, black reference data is not acquired. On the other hand, prior to the acquisition of the black reference data, the black reference data acquired at the previous image reading is stored in the black reference buffer area 103 a of the RAM 103 . Therefore, the CPU 101 adjusts the amount of light based on the acquired black reference data so that the white reference data becomes a desired output.

In step 320 (white reference data acquisition step), the image sensor 21 is caused to read the white reference portion 17a. At this time, the motor 23 is rotated forward and backward to reciprocate the image sensor 21 below the white reference portion 17a. The range of reciprocating movement is between point A and point B, wherein point A corresponds to a position 1 mm away from the left end of the white reference part 17a, and point B corresponds to a position 1 mm away from the right end of the white reference part 17a (see (2 in FIG. 11 ). ) part of the white reference part). And, during this reciprocating movement, the light receiving element of the image sensor 21 is made to acquire a plurality of data at different positions of the white reference portion 17a. Then, in order to average the acquired data, it is divided by the number of readings performed for each light-receiving element, and is stored in the white reference buffer area 103 b of the RAM 103 as white reference data.

In step 330, CPU 101 moves image sensor 21 from below white reference portion 17a to below black reference portion 17b (light absorbing portion area) (from (2) white reference portion to (3) black reference portion in FIG. 11 the movement). The moved image sensor 21 is located below the black reference portion 17b as shown in FIG. 9( b ). Then, the CPU 101 turns off the light source of the image sensor 21 until the image sensor 21 reaches below the black reference portion 17b.

In step 340 (black reference data acquisition step), in order to read the black reference data, reading is performed a plurality of times while the light source of the image sensor 21 is turned off. Since the light source of the image sensor 21 is turned off, the black reference data can be acquired immediately when the image sensor 21 is located under the black reference portion 17b. And, in order to average the obtained data, it is divided by the number of times of reading for each light receiving element, and is stored as black reference data in the black reference buffer area 103 a of the RAM 103 .

In step 350 , CPU 101 generates black shading data using the black reference data acquired in step S340 described above, and generates white shading data using the white reference data acquired in step S320 described above. The generated shading data of each color is recorded in RAM 103 .

In step 360, CPU 101 moves image sensor 21 to the reading start position. This reading start position is the ADF reading position shown in FIG. 3( a ) when reading a document conveyed by the document conveying device 40 . Moreover, when reading the document placed on the stationary document reading area 11, as shown in FIG. 3(b) and (4) the reading start position in FIG. below. Further, as described above, the document P is read by illuminating the document P with light from the image sensor 21 and reading the reflected light by the light receiving element.

In this way, in this embodiment, when the second processing method (refer to FIG. 8 ) of light quantity adjustment and shadow data calculation processing is adopted, since the image sensor 21 reaches the black reference part 17b from the initial position via the bottom of the white reference part 17a The image sensor 21 only needs to move in a short distance. The time required to generate shading data can thereby be shortened.

Example 2

The structure and function of the image reading device 1 in the second embodiment are basically the same as those in the first embodiment described above.

However, in the second embodiment, as shown in FIG. 12 , the positioning member 17 has a second light absorbing portion 17 g (second light absorbing portion) on the side of the moving document scanning area 12 . The second light absorbing portion 17g has a horizontal lower surface and an inclined plate-like member whose upper surface gradually becomes lower toward the outside (moving document scanning area 12 side). And the lower surface of the 2nd light absorption part 17g exists in the same plane as the white reference part 17a and the black reference part 17b, and is black like the black reference part 17b.

The image reading device 1 of the second embodiment has a second light absorbing portion 17g, as shown in FIG. of interfering light. Therefore, it is possible to further reduce the disturbance light incident on the white reference portion 17a, and it is possible to more accurately generate shading data.

In the second embodiment, the inner surface 3 a of the housing of the device main body 2 is black, and serves as the third light absorbing portion. Therefore, the disturbing light passing through the platen glass 13 and reaching the housing inner surface 3 a can be absorbed by the inner surface 3 a without reaching the white reference portion 17 a. Therefore, in the second embodiment, the disturbance light incident on the white reference portion 17a can be further reduced, and the shading data can be generated more accurately.

Example 3

The structure and function of the image reading device 1 in the third embodiment are basically the same as those in the first embodiment described above. However, in Embodiment 3, light amount adjustment and shadow data calculation processing are performed as shown in FIG. 13 .

In step 400, when the start button of the operation unit 15 is pressed, the CPU 101 issues a command to rotate the motor 23 to start moving the image sensor 21 to obtain black reference data and white reference data. The image sensor 21 moves a certain distance from the home position HP, and stops below the white reference portion 17a. As shown in FIG. 9( a ), the moved image sensor 21 is located below the white reference portion 17 a. In addition, the standby position of the image sensor 21, that is, the HP and the method (standby process) of the image sensor 21 at the standby position are the same as those in the first embodiment described above.

In step 410 (black reference data acquisition step), in order to read and scan the black reference data for the white reference portion 17a, reading is performed a plurality of times with the light source of the image sensor 21 turned off. And, in order to average the obtained data, it is divided by the number of times of reading for each light receiving element, and is stored in the black reference buffer area 103 a of the RAM 103 as black reference data.

In step 420 , CPU 101 adjusts the light intensity of the light source of image sensor 21 to a light intensity suitable for reading the white reference data. The method of adjusting the amount of light is the same as in the first embodiment described above.

In step 430 (white reference data step), the image sensor 21 is caused to read the white reference portion 17a. At this time, the motor 23 is rotated forward and backward to reciprocate the image sensor 21 below the white reference portion 17a. The reciprocating range is between point A and point B, where point A corresponds to a position 1 mm from the left end of the white reference part 17a, and point B corresponds to a position 1 mm from the right end of the white reference part 17a. During the reciprocating movement, the light receiving element of the image sensor 21 acquires a plurality of data at different positions of the white reference part 17a. In addition, in order to average the obtained data, it is divided by the number of readings for each light-receiving element, and is stored in the white reference buffer area 103 b of the RAM 103 as white reference data.

In step 440 , CPU 101 generates shadow data using the black reference data acquired in step 410 described above and the white reference data acquired in step 430 described above. The generated shadow data is stored in RAM103.

In step 450, CPU 101 moves image sensor 21 to the reading start position. Then, similarly to the embodiment, the original P is illuminated by the light source of the image sensor 21, and the reflected light is read by the light receiving element, whereby the image of the original P is read. In this manner, in the third embodiment, the black reference data is obtained by reading the white reference portion 17 a while the light source of the image sensor 21 is turned off.

In Embodiment 3, since the black reference data and the white reference data are acquired with the image sensor 21 under the white reference portion 17a, the image sensor 21 only needs to move a small number of times, and the image sensor 21 moves a short distance. That's it. Therefore, it is easy to control the image sensor 21, and the time required to generate shadow data is shortened.

The present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the gist of the present invention.

For example, in the first to third embodiments described above, the arrangement of the white reference portion 17a and the black reference portion 17b may be reversed. That is, on the lower surface of the positioning member 17 , the black reference portion 17 b may be arranged on the side of the moving document scanning area 12 , and the white reference portion 17 a may be arranged at the center of the lower surface of the positioning member 17 .

In Embodiments 1 to 3 above, although the white reference part 17a and the black reference part 17b are used as different components, and the black reference part 17b is provided so as to cover the white reference part 17a, it is also possible to distinguish them by painting white and black, etc. On the other hand, the white reference portion 17a and the black reference portion 17b are constituted by one member.

In addition, in the above-mentioned Embodiments 1 to 3, although the CIS is used as the image sensor 21 which is the reading device, in addition to the contact-type image sensor such as the reading device CIS of the present invention, for example, a compact optical system can also be used. CCD image sensor.

Claims (25)

1. image read-out comprises:

Transparent panel has the original copy placed side of placing original copy;

Fetch equipment is configured in a side opposite with described original copy placed side by described transparent panel, utilizes light source to carry out illumination and reads this reverberation;

Driving arrangement makes described fetch equipment move back and forth along described transparent panel;

Setting element is used for the original copy on the original copy placed side that is placed on described transparent panel is positioned;

Light absorption department absorbs the stray light that incides the transparent panel side of setting element by described transparent panel; And

White reference portion is located at the transparent panel side of described setting element; It is characterized in that,

Described transparent panel is independent transparent panel;

Described setting element is arranged on described transparent panel is divided on the position in a plurality of zones, the described a plurality of zones that are divided into by described setting element comprise mobile Manuscript scanner zone and static Manuscript scanner zone, move in the Manuscript scanner zone at this, the original copy that the upside that described fetch equipment reads in described transparent panel is transmitted by the transfer equipment that is used to transmit original copy, in this static Manuscript scanner zone, when described fetch equipment moved, described fetch equipment read the original copy that is placed on the described transparent panel;

With described light absorption department and described white reference portion in abutting connection with the transparent panel side that is configured in described setting element.

2. image read-out as claimed in claim 1, wherein, described light absorption department is in the transparent panel side of described setting element, is arranged near the central authorities of described setting element.

3. image read-out as claimed in claim 1, wherein, described fetch equipment reads original copy in mobile Manuscript scanner zone, and this original copy is to be sent to apart from a setting element side far away from the nearer side of distance setting element by the top of transfer equipment along transparent panel.

4. image read-out as claimed in claim 1 wherein, disposes described light absorption department, makes described image-reading device stretch out to described mobile original copy transit area side at least from the position that obtains the black reference data.

5. image read-out as claimed in claim 1, wherein, the length of described light absorption department on main scanning direction equals or exceeds transparent panel; And described fetch equipment moves back and forth on the sub scanning direction vertical with main scanning direction along described transparent panel.

6. image read-out as claimed in claim 1 wherein, is configured in mobile Manuscript scanner area side with described white reference portion with respect to described light absorption department, and disposes second light absorption department with respect to this white reference portion in mobile Manuscript scanner area side.

7. image read-out as claimed in claim 1, wherein, the part of described white reference portion is covered by described light absorption department, so that the border of extending along the main scanning direction of described fetch equipment is being provided near the mobile Manuscript scanner zone, and providing two borders of between described white reference portion and light absorption department, extending near the scanning constant zone along the sub scanning direction of described fetch equipment between described white reference portion and light absorption department.

8. image read-out as claimed in claim 1, wherein, the length of described white reference portion on main scanning direction equals or exceeds the length of transparent panel; And utilize roughly the oolemma that extends along described white reference portion to be connected on the described transparent panel at the edge that joins with mobile Manuscript scanner zone.

9. image read-out as claimed in claim 6 wherein, also comprises the 3rd light absorption department on the inner surface that is arranged on apparatus main body.

10. image read-out as claimed in claim 9, wherein, described light absorption department, second light absorption department and the 3rd light absorption department are roughly black.

11. image read-out as claimed in claim 1, wherein,

Also comprise the control appliance that is used to control described fetch equipment and described driving arrangement;

Described control appliance makes described fetch equipment obtain the white reference data in the white reference zone that can read described white reference portion; And

Make described fetch equipment in can read the light absorption department zone of described light absorption department, under the state that light source is turned off the light, obtain the black reference data.

12. image read-out as claimed in claim 11, wherein, described control appliance moves described fetch equipment along sub scanning direction in the white reference zone, and obtain the white reference data on a plurality of positions in the white reference zone; Described a plurality of position is mutually different position on sub scanning direction, and each position is the position of extending on the main scanning direction vertical with sub scanning direction of fetch equipment.

13. image read-out as claimed in claim 12, wherein, described control appliance moves back and forth described fetch equipment in the white reference zone, and utilizes described fetch equipment to obtain described white reference data.

14. image read-out as claimed in claim 12, wherein, when obtaining described black reference data, described control appliance stops described fetch equipment, obtains a plurality of black reference datas at regular intervals.

15. image read-out as claimed in claim 11, wherein, described control appliance makes described fetch equipment move to described light absorption department zone and obtain the black reference data from the position of readiness of regulation, then, make described fetch equipment move to described white reference zone and obtain the white reference data.

16. image read-out as claimed in claim 11, wherein, described control appliance makes described fetch equipment from moving to described white reference zone and obtain the white reference data than the position of readiness of described light absorption department zone near described white reference zone, then, make described fetch equipment further move to described light absorption department zone and obtain the black reference data.

17. image read-out as claimed in claim 16, wherein, described control appliance makes described fetch equipment move to described white reference zone from described position of readiness, carries out the light quantity adjustment adjusting the light quantity of described light source, and obtains the white reference data.

18. image read-out as claimed in claim 16, wherein, described control appliance keeps the black reference data obtained, and adjusts the light quantity of light source when adjusting according to this black reference data carrying out described light quantity.

19. image read-out as claimed in claim 16, wherein, make described fetch equipment move to from described white reference zone described light absorption department zone during in, described control appliance is turned off the light described light source.

20. an image reading method uses image read-out as claimed in claim 1, it is characterized in that, comprising:

The white reference data are obtained operation, described fetch equipment is moved in the white reference zone that can read described white reference portion, and under the state that utilizes the described white reference of described light source irradiation portion, make described fetch equipment on a plurality of positions of described white reference portion, obtain the white reference data; With

The black reference data is obtained operation, makes described fetch equipment in described white reference zone or stop below described light absorption department, obtains the black reference data at regular intervals under the state that described light source is turned off the light.

21. an image reading method uses image read-out as claimed in claim 1, it is characterized in that, comprising:

The black reference data is obtained operation, makes described fetch equipment move to the light absorption department zone that can read described light absorption department from the position of readiness of regulation, obtains the black reference data for this light absorption department zone under the state that light source is turned off the light; With

The white reference data are obtained operation, and described fetch equipment moves to the white reference zone that can read described white reference portion from described light absorption department zone, obtain the white reference data for this white reference zone.

22. an image reading method uses image read-out as claimed in claim 1, it is characterized in that, comprising:

The standby operation, make described fetch equipment than described light absorption department near the position of readiness of described white reference portion on standby;

The white reference data are obtained operation, make described fetch equipment move to the white reference zone that can read described white reference portion from described position of readiness, obtain the white reference data for this white reference zone; With

The black reference data is obtained operation, makes described fetch equipment move to the light absorption department zone that can read described light absorption department from described white reference zone, obtains the black reference data for this light absorption department zone under the state that light source is turned off the light.

23. image reading method as claimed in claim 22, wherein, described white reference data are obtained operation, before obtaining the white reference data for described white reference zone, carry out the adjustment of the light source light quantity of described fetch equipment for this white reference zone.

24. image reading method as claimed in claim 23, wherein, described white reference data are obtained operation, adjust the light quantity of described light source according to the black reference data of having obtained.

25. image reading method as claimed in claim 22, wherein, described black reference data is obtained operation, make described fetch equipment move to from described white reference zone described light absorption department zone during in, described light source is turned off the light.

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