Patent Application
20240397008
The disclosure relates to an image scanning device including an image scanning sensor including a substrate provided with a plurality of scanning elements and electronic components, and an image forming device such as a copying machine or a multifunction peripheral.
As an image scanning device, for example, there is an image scanning device that includes an image scanning sensor including a substrate provided with a plurality of scanning elements and electronic components provided, conveys a document to be scanned by the image scanning sensor toward an image scanning position, and scans the document conveyed to the image scanning position by the image scanning sensor.
In such an image scanning device, when continuously scanning a large number of documents, the temperature of the image scanning sensor increases due to continuous use of the image scanning sensor, and there is inconvenience of occurrence of density unevenness in a formed image.
This will be described below by taking, as an example, a case where for example, a contact image sensor is used as the image scanning sensor and a semiconductor IC chip is used as the electronic component.
As shown in
As illustrated in
In such an image scanning sensor 210, as shown in
On the other hand, even after the shading correction, when the plurality of documents G to G (for example, a large number of documents exceeding 100 sheets) are continuously scanned, the temperature of the semiconductor IC chip 213 in the substrate 211 increases. As a result, on the opposite surface 211b opposite to the substrate 211 in the image scanning sensor 210, the temperature of the electronic component placement location βa in the scanning element corresponding region β is higher than that of the other region βb, and the temperature of the scanning elements 212a to 212a near the electronic component placement location βa is higher than that of the scanning elements 212a to 212a and 212a to 212a in the other regions βb and βb, respectively. Then, the output values of the scanning elements 212a to 212a (see
In this regard, there is a configuration in which dimming control for reducing a light amount of a light source unit is performed in a gap portion between recording media which are continuously conveyed.
However, in the above-described configuration, although the dimming control for reducing the light amount of the light source unit is performed between the recording media, the problem caused by the temperature rise of the electronic component on the substrate is not dealt with at all.
Thus, it is an object of the disclosure to provide an image scanning device and an image forming device capable of suppressing occurrence of density unevenness in a formed image between the image near the electronic component placement location and the image in the location away from the electronic component placement location.
In order to solve the problem, an image scanning device according to the disclosure includes an image scanning sensor including a substrate provided with a plurality of scanning elements and electronic components, and conveys a document toward an image scanning position scanned by the image scanning sensor, and scans the document conveyed to the image scanning position by the image scanning sensor, and the image scanning device includes a power supply controller that controls supply of power to the electronic component in the image scanning sensor, when scanning the document, conveys the document toward the image scanning position in a power supply stop state in which power supply to the electronic component is stopped by the power supply controller, sets a power supply state in which power is supplied to the electronic component by the power supply controller before scanning the document at the image scanning position, scans the document at the image scanning position in the power supply state, and sets the power supply stop state after scanning the document at the image scanning position.
An image forming device according to the disclosure is an image forming device including the image scanning device according to the disclosure.
According to the disclosure, occurrence of density unevenness in a formed image between an image near an electronic component placement location and an image in a location away from the electronic component placement location can be suppressed.
In
An embodiment according to the disclosure will be described below with reference to the drawings. In the following description, the same components are denoted by the same reference signs. The names and functions of the components are also the same. Accordingly, detailed descriptions are not repeated.
The image forming device 100 includes the image scanning device 400 and an image forming device body 110.
The image scanning device 400 is provided at an upper portion of the image forming device body 110, and includes the image scanner 200 and a document conveyor 300 (automatic document feeding device). The image scanner 200 includes a document scanning member 200a (to be specific, a document scanning glass) that defines a first image scanning position R1 (an example of the image scanning position) (see
The document table 200b is provided above the image scanner 200. The document conveyor 300 automatically conveys the document G toward the first image scanning position R1 and the second image scanning position R2. In addition, the document conveyor 300 is provided so as to be openable and closable around an axis along a sub-scanning direction Y on a rear surface side that is the first side in the main scanning direction X with respect to the image scanner 200. Here, the main scanning direction X is a direction orthogonal to the conveying direction D of the document G, and the sub-scanning direction Y is a direction parallel to the convey direction of the document G. The rear surface side (second side Y2 in the sub-scanning direction Y) is an opposite side to an operation side (first side Y1 in the sub-scanning direction Y). Reference sign Z indicates an up-down direction.
The document conveyor 300 is rotatably supported by a hinge with respect to the image scanner 200. The document conveyor 300 opens the document table 200b and also serves as an example of a document presser pressing the document G placed on the document table 200b from above.
The image forming device 100 includes an image former 111 (see
The image former 111 includes an optical scanning device 11, a development device 12, a photoreceptor drum 13, a drum cleaning device 14, a charger 15, an intermediate transfer belt device 20, a fixing device 17, and a secondary transfer device 26. The image data used in the image forming device 100 corresponds to a color image using a plurality of (four in this example) colors such as black (K), cyan (C), magenta (M), and yellow (Y). Accordingly, in this example, four development devices 12, four photoreceptor drums 13, four drum cleaning device 14, and four chargers 15, are provided and set to black, cyan, magenta, and yellow to form four latent images, respectively, corresponding to each color. Four image stations Pa, Pb, Pc, and Pd are configured. The image forming device 100 further includes a feed tray 18 and a discharge tray 39.
In the image forming device 100, the sheet P supplied by the feed tray 18 is conveyed to sheet registration rollers 34 by conveying rollers 35 along a sheet conveyance path Ra. Next, the sheet P is conveyed to a transfer roller 26a by the sheet registration rollers 34 at a timing at which the sheet P and a toner image on an intermediate transfer belt 21 circulating in a circumferential direction C are aligned with each other. The toner on the intermediate transfer belt 21 is transferred onto the sheet P by the transfer roller 26a. Thereafter, the sheet P passes through a fixing roller 31 and a pressure roller 32 in the fixing device 17, and is discharged onto the discharge tray 39 via sheet discharge rollers 36. When image formation is performed not only on the front surface but also on the back surface of the sheet P, the sheet P is conveyed in the reverse direction from the sheet discharge rollers 36 to a reverse sheet conveyance path Rb. The sheet P is reversed via reverse conveying rollers 35a and is guided again to the sheet registration rollers 34. After the toner image is formed and fixed on the back surface of the sheet P in the same manner as the front surface, the sheet P is discharged toward the discharge tray 39.
The image scanning device 400 includes the image scanning units 220 (220a and 220b).
The image scanner 200 includes a document scanning member 200a having a transparent plate shape, the document table 200b having a transparent plate shape, a housing 200c, a scanning unit 230 (scanning body), and a driver 240 (scanner motor) (see
The scanning unit 230 is provided with the first image scanning unit 220 (220a). The first image scanning unit 220 (220a) includes the first image scanning sensor 210 (210a) (in this example, a contact image sensor) that scans the document G. The scanning unit 230 is provided below the document scanning member 200a and the document table 200b to be capable of reciprocating along the sub-scanning direction Y with respect to the housing 200c, and is driven by the driver 240.
Specifically, the housing 200c is provided with a guide shaft 200d (see
The image scanning device 400 is configured to perform a document moving scanning operation and a document fixed scanning operation under an instruction from a controller 70.
In the document moving scanning operation, the image scanning device 400 stops the scanning unit 230 at the first image scanning position R1 below the document scanning member 200a by the driver 240, and scans the front surface of the document G conveyed by the document conveyor 300 and passing over the document scanning member 200a. by the first image scanning sensor 210 (210a) in the first image scanning unit 220 (220a). When scanning the back surface of the document G in the document moving scanning operation, the image scanning device 400 scans the back surface of the document G conveyed by the document conveyor 300 and passing through the second image scanning unit 220 (220b) by the second image scanning sensor 210 (210b) in the second image scanning unit 220 (220b).
In addition, in the fixed document scanning operation, the image scanning device 400 scans the document G placed on the document table 200b by the first image scanning sensor 210 (210a) in the first image scanning unit 220 (220a) while moving the scanning unit 230 to the first side Y1 in the sub-scanning direction Y along the document table 200b.
In the image scanning device 400, the document G is conveyed toward the image scanning positions (R1 and R2) scanned by the image scanning sensors 210 (210a and 210b), and the document G conveyed to the image scanning positions (R1 and R2) is conveyed to the downstream side from the image scanning positions (R1 and R2) in the conveying direction D of the document G while being scanned by the image scanning sensors 210 (210a and 210b).
The document conveyor 300 includes a document placement tray 310, a supply roller 320, a document conveyance path S, a first conveying roller 330, a document registration roller 340, a second conveying roller 350, third conveying rollers 360, document discharge rollers 370, and a document discharge tray 380.
The document placement tray 310 is for placing one or a plurality of the documents G, and is disposed above the document conveyor 300. The supply roller 320 pulls out the documents G placed on the document placement tray 310 one by one. The supply roller 320 includes a take-in roller 321 (pickup roller), a supply roller 322, and a separation member 323 (in this example, a separation roller) such as a separation roller or a separation pad. The take-in roller 321 feeds the document G placed on the document placement tray 310 from the document placement tray 310 into the document conveyance path S along the conveying direction D of the document G. The feed roller 322 further conveys the document G fed by the take-in roller 321 to the downstream side in the conveying direction D while nipping the document G along with the separation member 323. The separation member 323 is in a state of facing the feed roller 322 and separates the documents G so that the document G conveyed between the separation member 323 and the feed roller 322 becomes one sheet.
The document conveyance path S guides the document G pulled out by the supply roller 320 to the discharge side (below the document placement tray 310) via the document scanning member 200a. The first conveying roller 330, the document registration roller 340, the second conveying roller 350, the third conveying rollers 360, and the document discharge rollers 370 are provided on the document conveyance path S. The first conveying roller 330 conveys the document G pulled out by the supply roller 320 to the document registration roller 340. The document registration roller 340 conveys the document G conveyed by the first conveying roller 330 onto the document scanning member 200a. The second conveying roller 350 conveys the document G conveyed from the document scanning member 200a toward the third conveying rollers 360. The third conveying rollers 360 cause the document G conveyed by the second conveying roller 350 to pass through the second image scanning sensor 210 (210b) and convey the document G toward the document discharge rollers 370. The document discharge rollers 370 discharge the document G conveyed from the third conveying rollers 360 toward the document discharge tray 380. The document discharge tray 380 is disposed below the document placement tray 310, and places the document G discharged by the document discharge roller 370.
As illustrated in
The first document detector 301 (301a) (in this example, an actuator type photosensor) is provided on the upstream side from the first image scanning position R1 in the conveying direction D in the document conveyance path S (in this example, near the upstream side of the document registration roller 340). The second document detector 301 (301b) (in this example, an actuator type photosensor) is provided on the upstream side from the second image scanning position R2 in the conveying direction D in the document conveyance path S (in this example, near the upstream side of the third conveying rollers 360).
As illustrated in
The light sources 221 and 221 irradiate the document G with the emission light La and La, respectively. The condenser lens array 222 condenses the reflected light Lb (image light) reflected from the document G on the scanning element unit 212 in the image scanning sensor 210. The image scanning sensors 210 (210a and 210b) each photoelectrically converts the reflected light Lb received by the scanning element unit 212 through the condenser lens array 222 and outputs image data. The scanning element unit 212 includes a plurality of (to be specific, 5184) scanning elements 212a to 212a arranged side by side on the substrate 211 along the main scanning direction X, and is a line image sensor in this example. The substrate 211 of the image scanning sensors 210 (210a and 210b) is provided with the plurality of scanning elements 212a to 212a and the electronic components (in this example, the semiconductor IC chips 213). Examples of the semiconductor IC chip 213 include a chip that converts an analog signal into a digital signal and a chip that amplifies an analog signal, and typically an analog front-end IC chip (AFE) (in this example, 10 mm×10 mm chip) that adjusts (for example, converts an analog signal into a digital signal) an analog signal output from the plurality of scanning elements 212a to 212a.
The image scanning units 220 (220a and 220b) each has the same configuration as a known configuration illustrated in
That is, as illustrated in
The image scanning sensors 210 (210a and 210b) each converts the reflected light Lb from the document G into an electric signal as image data.
In this example, the image scanning sensors 210 (210a and 210b) each is referred to as a contact image sensor (CIS), and has a shape elongated in the main scanning direction X. More specifically, the light sources 221 and 221 irradiate the front surface of the document G at the first image scanning sensor 210 (210a) and irradiate the back surface of the document G at the second image scanning sensor 210 (210b), respectively, with the emission light La and La. The light sources 221 and 221 are light emitting diode elements (LED). The condenser lens array 222 forms an image of the reflected light Lb reflected from the document G at the same magnification. The condenser lens array 222 is an erecting equal-magnification lens. The plurality of scanning elements 212a to 212a receive the reflected light Lb that has passed through the condenser lens array 222.
As illustrated in
The controller 70 is connected to the storage 72 via an internal bus 75. The image scanning device 400 and the image former 111 are connected to the controller 70 via the internal bus 75.
The controller 70 controls the entire image forming device 100. The nonvolatile memory 72a stores a start-up program of the image forming device 100 and default values for various kinds of information. The volatile memory 72b is used as a working area and a buffer area of the controller 70.
The semiconductor IC chips 213 (213a and 213b) (AFE) are electrically connected to an output system of the controller 70. As a result, the controller 70 can supply power to the semiconductor IC chips 213 (213a and 213b).
The image scanning sensors 210 (210a and 210b) are electrically connected to an input system of the controller 70. As a result, the controller 70 can receive the image signal from the image scanning sensors 210 (210a and 210b).
The document detectors 301 (301a and 301b) are electrically connected to the input system of the controller 70. As a result, the controller 70 can supply power to the semiconductor IC chips 213 (213a and 213b) before reaching the image scanning positions (R1 and R2) by detecting a leading edge of the document G by the document detectors 301 (301a and 301b), that is, at a timing when scanning can be performed by the scanning element unit 212 when the semiconductor IC chips 213 (213a and 213b) (AFE) is activated by power supply to the semiconductor IC chips 213 (213a and 213b).
In
Here, the first document G is a document that is placed on the document placement tray 310 and is first conveyed from the document placement tray 310 toward the scanning position by an execution key provided on an operation panel (not illustrated). The second and subsequent documents G are documents to be conveyed next after the first document is conveyed.
The controller 70 includes a power supply controller P1 and a first scanning controller P2. The power supply controller P1 controls power supply to the electronic components (semiconductor IC chips 213 (213a and 213b)) in the image scanning sensors 210 (210a and 210b), respectively. When scanning the document G, the first scanning controller P2 conveys the document G toward the image scanning positions (R1 and R2) in a power supply stop state in which power supply to the electronic components (213 (213a and 213b)) is stopped by the power supply controller P1. The first scanning controller P2 sets a power supply state in which power is supplied to the electronic components (213 (213a and 213b)) by the power supply controller P1 before scanning the document G at the image scanning positions (R1 and R2), scans the document G at the image scanning positions (R1 and R2) in the power supply state, and sets the power supply stop state after scanning the document G at the image scanning positions (R1 and R2). In the following description, the power supply state may be referred to as a power-up state, and the power supply stop state may be referred to as a power-down state.
In this example, when continuously scanning a plurality of the documents G to G and scanning the second and subsequent documents G to G, after the scanning of a preceding document G at the image scanning positions (R1 and R2) is ended (ST6: see the lower drawing in
Next, the first scanning controller P2 sets the power-up state (power supply state) in which the reference power is supplied to the electronic components (213 (213a and 213b)) by the power supply controller P1 before scanning the subsequent document G at the image scanning positions (R1 and R2), (ST9: see the lower drawing in
Specifically, as illustrated in
Next, the first scanning controller P2 and the second scanning controller P3 convey the document G while scanning the document G at the image scanning positions (R1 and R2), respectively, in the power-up state (ST11: see the lower drawing in
Next, as illustrated in
Occurrence of the density unevenness in a formed image between the image near the electronic component placement location βa and the image in the location away from the electronic component placement location βa can be suppressed by executing the shading correction for each scanning of the document G. However, the shading correction cannot be performed within the limited period of time between the preceding document G and the succeeding document G. This is particularly remarkable when the shading correction accompanying movement (which requires time for movement) of the first image scanning sensor 210 (210a) between the shading position R4 (see
In this regard, according to the present embodiment, when scanning the second and subsequent documents G, the document G is conveyed toward the image scanning positions (R1 and R2) in the power-down state (power supply stop state) without executing the shading correction for each scanning of the document G, the power-up state (power supply state) is set before scanning the document G at the image scanning positions (R1 and R2), the document G is scanned at the image scanning positions (R1 and R2) in the power-up state (power supply state), and the power-down state (power supply stop state) is set after scanning the document G at the image scanning positions (R1 and R2).
As described above, the power-down state (power supply stop state) can be set on the electronic components (213 (213a and 213b)) between the preceding document G and the succeeding document G which are continuously scanned without executing the shading correction for each scanning of the document G. Thus, even when the plurality of documents G to G are continuously scanned, an increase in the temperature of the electronic components (213 (213a and 213b)) on the substrate 211 can be suppressed. As a result, the temperature of the scanning elements 212a to 212a near the electronic component placement location βa can be suppressed to be higher than that of the scanning elements 212a to 212a and 212a to 212a in the other regions βb and βb, respectively. Consequently, occurrence of density unevenness in a formed image between the image near the electronic component placement location βa and the image in the location away from the electronic component placement location βa can be suppressed.
This is particularly effective when the image scanning sensors 210 (210a and 210b) are contact image sensors and the electronic components are the semiconductor IC chips 213 (213a and 213b) (analog front-end IC chips in this example) provided on the scanning element corresponding region β on the opposite surface 211b of the substrate 211 in the image scanning sensors 210 (210a and 210b) or at the predetermined electronic component placement location βa near the scanning element corresponding region β.
In some cases, it is preferable to execute the shading correction when a job is requested. For example, in a case where the plurality of documents G to G are continuously scanned in a previous job, a next job may be executed while the temperature of the electronic components (213 (213a and 213b)) increases and the temperature of the electronic components (213 (213a and 213b)) does not completely decrease.
In this regard, in the present embodiment, the controller 70 further includes the second scanning controller P3.
When scanning the first document G (i.e., for each job request), the second scanning controller P3 sets the power-up state (power supply state) by the power supply controller P1 (ST1: see the upper drawing in
The controller 70 scans the first document G at the image scanning positions (R1 and R2) remaining the power-up state (power supply state) (ST3: see the upper drawing in
In this way, the shading correction can be executed for each job request, and thus, occurrence of density unevenness can be suppressed for each job request. For example, when a plurality of documents G to G are continuously scanned in the previous job, even when the next job is executed while the temperature of the electronic components (213 (213a and 213b)) increases, and the temperature of the electronic components (213 (213a and 213b)) does not completely decrease, the shading correction is performed on the first document G. Thus occurrence of density unevenness in a formed image between the image near the electronic component placement location βa and the image in the location away from the electronic component placement location βa can be suppressed.
Here, the shading correction is correction for correcting unevenness in the amount of light to the plurality of scanning elements 210a to 210a in the image scanning sensors 210 (210a and 210b), and can perform correction by, for example, the following equation.
A gradation value Pout(i) after the shading correction of output values of the image scanning sensors 210 (210a and 210b) when the light sources 221 and 221 are turned on and the reflected light Lb reflected from the document G is received can be calculated by the following equation:
Pout(i)={[P(i)−K(i)]/[W(i)−K(i)]}×γ
where K(i) (i is an integer of 1 to n, n is the number of the scanning elements 212a to 212a, n=5184 in this example) is the output value of the image scanning sensors 210 (210a and 210b) when the light sources 221 and 221 are turned off, W(i) is the output value of the image scanning sensors 210 (210a and 210b) when the light sources 221 and 221 are turned on and the reflected light Lb reflected from a reference white plates 224 (224a and 224b) (shading plates) (see
In the present embodiment, the controller 70 performs a conveying process of conveying the first document G to the image scanning positions (R1 and R2) and a correction process of executing the shading correction in parallel.
In this way, while the first document G is conveyed to the image scanning positions (R1 and R2), the shading correction, in particular, the shading correction accompanying movement of the first image scanning sensor 210 (210a) can be performed, and accordingly, shortening of image scanning time of the first document G can be realized.
In the present embodiment, the controller 70 sets the power-up state (power supply state) when starting up the image scanning device 400 (image forming device 100), executes the shading correction in the power-up state (power supply state), and sets the power-down state (power supply stop state) after executing the shading correction.
In this way, the shading correction can be executed for each start-up of the image scanning device 400 (image forming device 100), and thus, the occurrence of the density unevenness can be suppressed for each start-up time.
In the present embodiment, the controller 70 sets the power-up state (power supply state) or the power-down state (power supply stop state) based on timing detection before scanning the document G at the image scanning positions (R1 and R2) and timing detection after scanning the document G at the image scanning positions (R1 and R2), which are detected using the document detectors 301 (301a and 301b) provided in the document conveyance path S.
In this way, the power-up state (power supply state) or the power-down state (power supply stop state) can be easily set using the existing document detectors 301 (301a and 301b) provided in the document conveyance path S of the document G.
As shown in
As shown in
As shown in
As shown in
As shown in
Here, in the case of the image scanning mode by the second image scanning sensor 210 (210b), it is difficult to clean the reference white plate 224 (224b), and thus the shading correction may be omitted. This is particularly effective in the color image scanning mode. In this case, when the shading correction is performed in the production process, there is no particular problem even when the shading correction is omitted.
The disclosure is not limited to the embodiments described above and can be implemented in various other forms. Thus, the above embodiments are merely examples in all respects and should not be interpreted as limiting. The scope of the disclosure is indicated by the claims and is not limited to the description. Furthermore, all modifications and changes equivalent in scope with the claims are included in the scope of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-086942 | May 2023 | JP | national |
