Image reading apparatus, image forming apparatus

An image reading apparatus includes a document sheet cover, a pressing portion, and a light irradiating portion. The document sheet cover is openable and closable with respect to a document sheet mounting surface. The pressing portion is provided in a recess formed in a counter surface of the document sheet cover that faces the document sheet mounting surface. The pressing portion is biased in a direction to project from the counter surface. When the document sheet cover is closed, the pressing portion contacts a document sheet placed on the document sheet mounting surface and is housed in the recess. The light irradiating portion is configured to irradiate light, toward the document sheet mounting surface, from a gap formed between a side wall of the recess and the pressing portion.

INCORPORATION BY REFERENCE

This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2013-241377 filed on Nov. 21, 2013, the entire contents of which are incorporated herein by reference.

BACKGROUND

The present disclosure relates to an image forming apparatus and an image reading apparatus provided with a document sheet cover.

In general, an image reading apparatus, such as a scanner, which can read an image from a document sheet placed on a document sheet mounting surface, is provided with a document sheet cover that is openable and closable with respect to the document sheet mounting surface. To cause such an image reading apparatus to read an image from a document sheet, the user places the document sheet on the document sheet mounting surface and closes the document sheet cover. After causing the image reading apparatus to execute the process of reading the image from the document sheet, the user opens the document sheet cover and takes out the document sheet from the document sheet mounting surface. Here, with the opening of the document sheet cover, it may happen that the document sheet is blown off from the document sheet mounting surface. In this regard, there is known a technique addressing this problem. According to this technique, a number of projections are provided on a counter surface of the document sheet cover that faces the document sheet mounting surface, to prevent the document sheet from being blown off when the document sheet cover is opened

SUMMARY

An image reading apparatus according to an aspect of the present disclosure includes a document sheet cover, a pressing portion, and a light irradiating portion. The document sheet cover is openable and closable with respect to a document sheet mounting surface. The pressing portion is provided in a recess formed in a counter surface of the document sheet cover that faces the document sheet mounting surface. The pressing portion is biased in a direction to project from the counter surface. When the document sheet cover is closed, the pressing portion contacts a document sheet placed on the document sheet mounting surface and is housed in the recess. The light irradiating portion is configured to irradiate light, toward the document sheet mounting surface, from a gap formed between a side wall of the recess and the pressing portion.

An image forming apparatus according to another aspect of the present disclosure includes an image reading apparatus and an image forming portion. The image reading apparatus includes a document sheet cover, a pressing portion, and a light irradiating portion. The document sheet cover is openable and closable with respect to a document sheet mounting surface. The pressing portion is provided in a recess formed in a counter surface of the document sheet cover that faces the document sheet mounting surface. The pressing portion is biased in a direction to project from the counter surface. When the document sheet cover is closed, the pressing portion contacts a document sheet placed on the document sheet mounting surface and is housed in the recess. The light irradiating portion is configured to irradiate light, toward the document sheet mounting surface, from a gap formed between a side wall of the recess and the pressing portion. The image forming portion is configured to form an image based on image data read by the image reading apparatus.

DETAILED DESCRIPTION

The following describes an embodiment of the present disclosure with reference to the accompanying drawings for the understanding of the disclosure. It should be noted that the following description is an example of a specific embodiment of the present disclosure and should not limit the technical scope of the present disclosure.

[Outlined Configuration of Image Forming Apparatus10]

First, an outlined configuration of an image forming apparatus10in an embodiment of the present disclosure is described. Here,FIG. 1Ais a schematic cross-sectional view of the image forming apparatus10.FIG. 1Bis a figure taken along the1B-1B line ofFIG. 1Aand viewed from a direction indicated by the arrows.

As shown inFIGS. 1A and 1B, the image forming apparatus10includes an ADF1, an image reading portion2, an image forming portion3, a sheet feed portion4, a control portion5, and an operation display portion6. The image forming apparatus10is a multifunction peripheral having a plurality of functions such as a printer function, a facsimile function, a copy function and the like, as well as a scan function to read image data from the document sheet. It is noted that, in the image forming apparatus10, a configuration including the ADF1and the image reading portion2is an example of the image reading apparatus of the present disclosure. In addition, the present disclosure is applicable to an image forming apparatus or an image reading apparatus such as a scanner, a facsimile apparatus, a copier or the like.

The image forming portion3is an image forming portion adopting the electrophotography and executes an image forming process (print process) based on the image data which is read by the image reading portion2or input from an external information processing apparatus such as a personal computer. Specifically, as shown inFIG. 1A, the image forming portion3includes a photoconductor drum31, a charging device32, an exposure device (LSU)33, a developing device34, a transfer roller35, a cleaning device36, a fixing roller37, a pressure roller38, and a discharge tray39. In the image forming portion3, an image is formed in the following procedure on a paper sheet supplied from a sheet feed cassette41that is attachable and detachable to/from the sheet feed portion4, and the paper sheet with the image formed thereon is discharged onto the discharge tray39.

First, the charging portion32charges the surface of the photoconductor drum31uniformly into a certain potential. Next, the exposure device33irradiates the surface of the photoconductor drum31with light based on the image data. With this operation, an electrostatic latent image corresponding to the image data is formed on the surface of the photoconductor drum31. Then the electrostatic latent image on the photoconductor drum31is developed (made visible) into a toner image by the developing device34. It is noted that the toner (developer) is supplied to the developing device34from a toner container34A that is attachable and detachable to/from the image forming portion3. Subsequently, the toner image formed on the photoconductor drum31is transferred to a paper sheet by the transfer roller35. The print sheet is then conveyed to pass through between the fixing roller37and the pressure roller38, where the toner image having been transferred to the print sheet is heated by the fixing roller37so as to be fused and fixed to the print sheet. It is noted that the toner remaining on the surface of the photoconductor drum31is removed by the cleaning device36.

The control portion5includes control equipment such as CPU, ROM, RAM, EEPROM, and the like that are not shown. The CPU is a processor for executing various types of arithmetic processes. The ROM is a nonvolatile storage portion in which various types of information such as control programs for causing the CPU to execute various types of processes are stored in advance. The RAM is a volatile storage portion, and the EEPROM is a nonvolatile storage portion. The RAM and the EEPROM are used as temporary storage memories (working areas) for the various types of processes executed by the CPU. The control portion5comprehensively controls the image processing apparatus10by causing the CPU to execute the various types of control programs that have been stored in advance in the ROM. It is noted that the control portion5may be formed as an electronic circuit such as an integrated circuit (ASIC). Alternatively, the control portion5may be a control portion provided independently of a main control portion that comprehensively controls the image processing apparatus10.

The operation display portion6includes a display portion and an operation portion. The display portion is, for example, a liquid crystal display and displays various types of information based on control instructions from the control portion5. The operation portion is composed of, for example, hard keys or a touch panel through which various types of information are input to the control portion5based on user's operations.

The image reading portion2is an image reading portion that can read image data from the document sheet. Specifically, as shown inFIGS. 1A and 1B, the image reading portion2includes a document sheet table21, a reading unit22, mirrors23,24, an optical lens25, and a CCD (Charge Coupled Device)26.

The document sheet table21is provided on the upper surface of the image reading portion2. As shown inFIG. 1B, the document sheet table21includes a document sheet mounting surface211and a conveying-and-reading surface212. The document sheet mounting surface211is translucent contact glass on which a document sheet, from which image data is to be read, is placed. Document sheets of various sizes can be placed on the document sheet mounting surface211to be positioned at a predetermined mounting reference position213. Specifically, document sheets of B5 vertical, A4 vertical, B5 horizontal, A4 horizontal, B4 horizontal, and A3 horizontal sizes can be placed on the document sheet mounting surface211. That is, the maximum readable size in the image forming apparatus10is A3 horizontal. It is noted that the mounting reference position213may be the center of the document sheet mounting surface211in a main scanning direction214. It is also noted that the conveying-and-reading surface212is made of glass and allows the light, which was irradiated from the reading unit22toward the document sheet conveyed by the ADF1, to transmit therethrough.

The reading unit22includes a light source221and a mirror222, and is configured to be driven and moved in a sub scanning direction215by a moving mechanism (not shown) that uses a driving source such as a stepping motor or the like. When the reading unit22is moved in the sub scanning direction215by the driving source, the light irradiated from the light source221toward the document sheet table21is scanned in the sub scanning direction215.

The light source221includes a number of white LEDs arranged along the main scanning direction214. The light source221irradiates the document sheet with a line of white light arrayed in the main scanning direction214from below the document sheet mounting surface211or the conveying-and-reading surface212of the document sheet table21, by causing the white light to pass through the document sheet mounting surface211or the conveying-and-reading surface212. It is noted that the white light irradiated by the light source221has a width along the main scanning direction214that corresponds to the document sheet mounting surface211. A light irradiation position where the light is irradiated by the light source221is an image data reading position where the image data is read by the image reading portion2. The reading position moves in the sub scanning direction215as the reading unit22moves in the sub scanning direction215. Specifically, when reading image data from a document sheet placed on the document sheet mounting surface211, the reading unit22is moved to a position where the light irradiated by the light source221passes through the document sheet mounting surface211. Here, the light source221is an example of the first light source. In addition, when reading image data from a document sheet conveyed by the ADF1, the reading unit22is moved to a position where the light irradiated by the light source221passes through the conveying-and-reading surface212.

The mirror222reflects, toward the mirror23, light which was irradiated from the light source221and reflected on the surface of the document sheet at the reading position on the document sheet table21. The light reflected on the mirror222is guided into the optical lens25by the mirrors23,24. The optical lens25condenses the light incident from the mirror24and makes the condensed light incident on the CCD26.

The CCD26is an image sensor including a photoelectric converting element that converts the received light into an electric signal (voltage), which corresponds to an amount of the received light, and outputs the electric signal as the image data. Upon receiving light incident from the light source221, the CCD26inputs an electric signal, which is based on the incident light that was reflected on the document sheet, to the control portion5as image data of the document sheet.

As shown inFIGS. 1A and 2, the ADF1is an automatic document sheet feeding device and includes a document sheet setting portion11, a plurality of conveying rollers12, a document sheet pressing13, a sheet discharge portion14, and a document sheet pressing15. The ADF1is supported so as to be openable and closable with respect to the document sheet table21, and also serves as a document sheet cover for covering the document sheet placed on the document sheet mounting surface211. Of course, a configuration where the image forming apparatus10includes, instead of the ADF1, a document sheet cover that is openable and closable with respect to the document sheet table21, may be considered as another embodiment of the present disclosure.

In the ADF1, the plurality of conveying rollers12are driven by motors (not shown) such that a document sheet placed on the document sheet setting portion11is conveyed to pass through an image data reading position where the image data is read by the image reading portion2, and then conveyed to the sheet discharge portion14. With this configuration, the image reading portion2can read image data from the document sheet conveyed by the ADF1. The document sheet pressing15is a counter surface of the ADF1that faces the document sheet mounting surface211, and is a white plate-shaped member or a white sheet member having a plane surface that is wide enough to cover the document sheet mounting surface211.

Meanwhile, when the ADF1is opened, it may happen that a document sheet placed on the document sheet mounting surface211is blown off therefrom. In this regard, there is known a technique where a number of projections are provided on the counter surface of the ADF1that faces the document sheet mounting surface211, to prevent the document sheet from being blown off when the ADF1is opened. However, according to this configuration using a plurality of projections, when the document sheet is irradiated with light during the image reading process, shadows are generated by the height difference of the projections and the shadows may affect the image data read from the document sheet. On the other hand, as described below, the image forming apparatus10restricts the document sheet from being blown off when the ADF1is opened, and reduces the influence of a member(s), which is required to restrict the movement of the document sheet, on the image data read from the document sheet.

First, a description is given of the configuration of the image forming apparatus10for restricting the document sheet from being blown off when the ADF1is opened, with reference toFIGS. 2 through 6.

In the image forming apparatus10, as shown inFIGS. 2 and 3, a pressing portion16and a recess17are provided in the ADF1. It is noted that the dotted chain lines inFIGS. 2 and 3indicate a predetermined maximum reading range X1 within the document sheet mounting surface211in the main scanning direction214. The maximum reading range X1 is a range corresponding to a document sheet of A3 horizontal size that is placed on the document sheet mounting surface211, positioned at the mounting reference position213.

The recess17is provided in the document sheet pressing15at a position corresponding to the mounting reference position213. It is noted that in the case where the mounting reference position213is the center of the document sheet mounting surface211in the main scanning direction214, the pressing portion16may be provided at a position corresponding to the mounting reference position213, and the recess17may be provided at a position outside the maximum reading range X1 in the main scanning direction214.

The recess17is a recess having a rectangular parallelepiped shape with a bottom, formed in the document sheet pressing15that is a counter surface of the ADF1that faces the document sheet mounting surface211, and is projecting toward the rear surface side of the document sheet pressing15. It is noted that the rear surface side of the document sheet pressing15is a space between the housing of the ADF1and the document sheet pressing15, or an internal space of the ADF1, and is not exposed to outside of the apparatus. In addition, as shown inFIGS. 5A and 5B, the recess17includes rail portions171that guide the sliding of the pressing portion16. Specifically, the rail portions171are openings formed to extend in a direction vertical to the document sheet pressing15.

The pressing portion16is slidably provided in the recess17. More specifically, as shown inFIGS. 5A and 5B, the pressing portion16includes a plurality of locking portions162that limit the sliding range of the pressing portion16with respect to the recess17. The locking portions162respectively have claws that project outside the opening formed in the document sheet pressing15. With the configuration where the claws of the locking portions162contact the edges of the recess17formed in the document sheet pressing15, the locking portions162restrict the movement of the pressing portion16in a direction to project from the document sheet pressing15.

Among the locking portions162, three locking portions162, except for one provided on the side of a first reflecting portion19(which is described below), can be moved in a direction vertical to the document sheet pressing15along the rail portions171of the recess17. It is noted that the locking portions162are formed in an elongated shape extending in parallel with the rail portions171such that the locking portions162close the rail portions171of the recess17in the state where the pressing portion16is housed in the recess17.

As shown inFIG. 4, a biasing member161is provided between the pressing portion16and the recess17, wherein the biasing member161biases the pressing portion16in a direction to project from the document sheet pressing15. Specifically, the biasing member161is an elastic member, such as a coil spring, wherein an end of the biasing member161is fixed to a bottom173of the recess17and the other end is fixed to the pressing portion16. As a result, when the ADF1is opened, the pressing portion16is biased by the biasing member161and projects from the document sheet pressing15. On the other hand, when the ADF1is closed, the pressing portion16contacts the document sheet placed on the document sheet mounting surface211, and is compressed and housed in the recess17.

When the ADF1is in the process of being opened and the document sheet pressing15is in the process of being separated from the document sheet, the pressing portion16projects from the document sheet pressing15and presses the document sheet. Subsequently, when the ADF1is further opened, the pressing portion16is separated from the document sheet, as well. With this configuration of the image forming apparatus10, the document sheet is restricted from being blown off when the ADF1is opened.

In addition, in the image forming apparatus10, in the state where the ADF1is closed, the pressing portion16is housed in the recess17. As a result, no height difference is generated between the document sheet pressing15and the pressing portion16. Accordingly, this reduces the influence of the presence of the pressing portion16and the recess17on the image data read from the document sheet.

Meanwhile, since the pressing portion16is slidable with respect to the recess17, a gap C1 (seeFIG. 4) is formed between the recess17and the pressing portion16. As a result, there is a possibility that the presence of the gap C1 may affect the image data. In view of this, the image forming apparatus10has a configuration for restricting the influence of the gap C1 on the image data.

The following describes the configuration that is provided in the image forming apparatus10to restrict the influence of the presence of the pressing portion16and the recess17on the image data read by the image reading portion2from the document sheet placed on the document sheet mounting surface211, with reference toFIGS. 2 through 6.

As shown inFIGS. 2 and 3, in the image forming apparatus10, the ADF1is provided with a translucent portion18and a first reflecting portion19. The translucent portion18is formed at a position that is outside the maximum reading range X1 in the main scanning direction214, and is included in the same range as the recess17in the sub scanning direction215. For example, the translucent portion18includes a through hole and a translucent plate-like member. The through hole is formed in the document sheet pressing15and penetrates through the front and rear surfaces of the document sheet pressing15. The plate-like member is inserted in the through hole. With this configuration, as shown inFIG. 6, when the reading unit22of the image forming apparatus10reads the image data, the translucent portion18causes light L1 irradiated from the light source221to be transmitted therethrough to the rear surface side of the document sheet pressing15. It is noted that the translucent portion18may be just an opening, without the plate-like member.

As shown inFIG. 3, the first reflecting portion19is a mirror disposed slanted on the rear surface of the document sheet pressing15, at a position above the translucent portion18. With this configuration, as shown inFIG. 6, the first reflecting portion19reflects the light L1, which has come from the light source221through the translucent portion18, toward the pressing portion16and the recess17.

On the other hand, as shown inFIGS. 5A and 5B, an opening172is formed in a counter surface of the recess17facing the first reflecting portion19, to make the light from the first reflecting portion19incident in the recess17. Similarly, as shown inFIGS. 5A and 5B, an opening163is formed in a counter surface of the pressing portion16facing the first reflecting portion19, to make the light from the first reflecting portion19incident in the recess17. As a result, in the state where the ADF1is closed, that is, in the state where the pressing portion16is housed in the recess17, the reflection light from the first reflecting portion19passes through the opening172of the recess17and the opening163of the pressing portion16and enters the inside of the recess17.

In addition, the biasing member161disposed in the recess17is a coil spring that is shaped to diffuse the light incident from the first reflecting portion19. Here, the biasing member161is an example of the light diffusion portion of the present disclosure. With this configuration, the light incident in the recess17is irradiated by the biasing member161toward the document sheet mounting surface211from the gap C1. It is noted that, in the state where the pressing portion16is housed in the recess17, the rail portions171are closed by the locking portions162, thereby restricting the diffusion light generated by the biasing member161from leaking outside the recess17. Meanwhile, the rail portions171may be grooves formed on the inner side of the side walls of the recess17, without openings in the side walls of the recess17. Furthermore, the biasing member161is not limited to a coil spring as far as it can diffuse the light incident from the first reflecting portion19.

The bottom173of the recess17functions as a reflection surface that reflects the diffusion light generated by the biasing member161toward the document sheet mounting surface211from the gap C1. Here, the biasing member161and the bottom173are an example of the second reflecting portion. In particular, a high-reflection sheet or the like having a high reflectance may be adhered to the bottom173. With this configuration, the bottom173irradiates the light, which is incident in the recess17, toward the document sheet mounting surface211from the gap C1. Here, the first reflecting portion19, the biasing member161, and the bottom173are an example of the light irradiating portion of the present disclosure.

As described above, in the image forming apparatus10, when the reading unit22reads image data from a document sheet placed on the document sheet mounting surface211, light is irradiated toward the document sheet mounting surface211from the gap C1. More specifically, when image data is read from a document sheet that corresponds to an area in the sub scanning direction215in which the pressing portion16and the recess17are formed, light is irradiated toward the document sheet mounting surface211from the gap C1. This reduces the influence of the pressing portion16and the recess17provided in the ADF1, on the image data read from the document sheet. For example, the configuration restricts a black shadow of the gap C1 from being read at a position corresponding to the gap C1. In addition, in the image forming apparatus10, the light irradiated from the light source221of the reading unit22is irradiated by the first reflecting portion19and the reflection surface173toward the document sheet mounting surface211from the gap C1. As a result, there is no need to independently provide a light source for irradiating light toward the document sheet mounting surface211from the gap C1.

Other Embodiments

Meanwhile, a configuration where the image forming apparatus10includes, independently of the light source221, a second light source for irradiating light toward the document sheet mounting surface211from the gap C1, may be considered as another embodiment of the present disclosure. For example, an LED light source (an example of the second light source) for irradiating white light may be provided inside the recess17. With this configuration, for example, when a document sheet of a size to cover the whole area of the document sheet mounting surface211is placed on the document sheet mounting surface211, the control portion5can cause the light to be irradiated from the gap C1 by lighting the light source provided inside the recess17.

In addition, a configuration where the image forming apparatus10includes a plurality of sets of the pressing portion16, recess17, translucent portion18, and first reflecting portion19in the document sheet pressing15at different positions in the sub scanning direction215, may be considered as a still another embodiment of the present disclosure. Furthermore, a configuration where the image forming apparatus10includes a plurality of sets of the pressing portion16, recess17, translucent portion18, and first reflecting portion19in the document sheet pressing15at positions different in both the sub scanning direction215and the main scanning direction214, may be considered as a further embodiment of the present disclosure. With such a configuration, locations pressing the document sheet placed on the document sheet mounting surface211are increased in number, and the document sheet is more effectively restricted from being blown off when the ADF1is opened.

Furthermore, the pressing portion16and the recess17are not limited to the shapes shown inFIGS. 4,5A, and5B. For example, as shown inFIGS. 7A and 7B, the image forming apparatus10may include, instead of the pressing portion16, a pressing portion160whose surface that contacts the document sheet is circular. In this case, as shown inFIGS. 7A and 7B, the image forming apparatus10includes, instead of the recess17, a recess170having a cylindrical shape with a bottom in correspondence with the shape of the pressing portion160. In the pressing portion160shown inFIGS. 7A and 7B, three locking portions162are provided at equal intervals along the circumferential direction of the pressing portion160. In this configuration of the pressing portion160and the recess170, as shown inFIGS. 7A and 7B, openings163of the pressing portion160are wider than their counterparts ofFIGS. 5A and 5B, and thus a more amount of light is irradiated from the first reflecting portion19into the recess170. It is noted that when the surface of the pressing portion160that contacts the document sheet is circular and the recess170has a cylindrical shape with a bottom, the pressing portion160can be slid stably with respect to the recess170even when the locking portions162are provided at three positions along the circumferential direction of the pressing portion160.