Image reading apparatus

An image reading apparatus includes: a contact glass provided at an upper surface of a main body of the apparatus to set a manuscript thereon, an image sensor being positioned below the contact glass and having a reading surface on contact glass side for reading an image from the manuscript on the contact glass, a carriage supporting the image sensor accommodated in a sensor container formed to have a recess open to the contact glass side, a rail member slidably supporting the carriage, and a biasing member biasing the image sensor to the contact glass side via a biased portion adjacent to the reading surface of the image sensor. An upper end of the biasing member is positioned below the contact glass and above the lower surface of the image sensor.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent Application No. 2011-219220, filed on Oct. 3, 2011, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image reading apparatus which is configured to read an image from a manuscript on a contact glass by an image sensor contained in a carriage.

2. Description of the Related Art

Conventionally, as image reading apparatuses, so-called flatbed type image reading apparatuses have been known. Such an image reading apparatus has a contact glass at the upper surface of its main body for setting a manuscript. The image reading apparatus is configured to read an image of the manuscript set on the contact glass by an image sensor provided inside the main body. Then, the image sensor is installed on a carriage which is set to be slidable on a rail provided inside the main body. The image sensor is configured to slide along the rail together with the carriage when reading the image of the manuscript.

The invention disclosed in Japanese Patent Application Laid-Open No. 08-163291 is known as an invention with respect to such image reading apparatuses described above. In the image reading apparatus disclosed in Japanese Patent Application Laid-Open No. 08-163291, the image sensor is placed on the carriage which is slidable along the rail. The image sensor is biased upward toward the contact glass by springs provided between the lower surface of the image sensor and the upper surface of the carriage.

Here, in the image reading apparatus disclosed in Japanese Patent Application Laid-Open No. 08-163291, the springs are provided between the lower surface of the image sensor and the upper surface of the carriage. Therefore, even if the springs are compressed to the limit, the springs still occupy a certain height. Therefore, the springs which occupy the certain height become an obstacle to the apparatus miniaturization which has been desired in recent years.

SUMMARY OF THE INVENTION

Accordingly, the present invention relates to image reading apparatuses which is configured to read an image from a manuscript on a contact glass by an image sensor contained in a carriage, and an object of the present invention is to provide an image reading apparatus capable of biasing the image sensor toward the contact glass by biasing means while facilitating miniaturization of the apparatus.

An image reading apparatus according to an aspect of the present invention includes a contact glass, an image sensor, a carriage, a rail member, and a biasing member, and is capable of reading an image from a manuscript set on the contact glass by sliding the image sensor, which is accommodated in a sensor container of the carriage, together with the carriage along the rail member. In the image reading apparatus according to the aspect of the present invention, because the biasing member biases the image sensor toward the contact glass via a biased portion adjacent to a reading surface of the image sensor which is accommodated in the sensor container, the biasing member is not positioned between a lower surface of the image sensor and a bottom surface of the sensor container. By virtue of this, it is possible for the image reading apparatus to facilitate miniaturization of the apparatus in its vertical direction. Further, because an upper end of the biasing member is positioned below the contact glass and above the lower surface of the image sensor, the image reading apparatus can reliably bias the image sensor toward the contact glass by the biasing force of the biasing member.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinbelow, referring to the accompanying drawings, explanations will be made in detail with respect to several embodiments in which an image reading apparatus according to the present invention is embodied as a multifunction apparatus1having a scanner unit10.

First Embodiment

First, referring toFIGS. 1 and 2, a schematic configuration of the multifunction apparatus1according to first embodiment will be explained. In the following explanations, with the multifunction apparatus1placed in a usable state as a reference, the up-down directions are defined as shown inFIG. 1. The lower right side inFIG. 1is defined as the front side of the multifunction apparatus1, and the upper left side inFIG. 1is defined as the rear side of the multifunction apparatus1. Further, with the multifunction apparatus1viewed from the front side as a reference in left-right direction, the lower left side inFIG. 1is defined as the left side of the multifunction apparatus1, and the upper right side is defined as the right side of the multifunction apparatus1.

As shown inFIG. 1, the multifunction apparatus1has a main body2and a top cover3. The main body2has a manuscript table11on an upper surface thereof. The manuscript table11has a contact glass16. The contact glass16is a so-called “platen glass”. The contact glass16is formed to have a rectangular shape slightly larger than maximum size of the manuscript which the multifunction apparatus1can read. A long side of the contact glass16is positioned along the left-right direction of the main body2. The contact glass16is used when the manuscript is set on the contact glass16and an image is read by moving an aftermentioned image sensor20which constitutes a scanner unit10.

Further, the main body2has the scanner unit10below the contact glass16, namely, in an upper part of inner space of the main body2. The scanner unit10has the image sensor20, a first carriage30, a slide shaft25, a reading transport motor, a flat cable, and the like. The scanner unit10reads an image of the manuscript set on the contact glass16. The configuration of the scanner unit10will be explained in detail hereinafter in reference to the relevant figures.

Then, the main body2contains a control section, a facsimile section, an image formation section and the like below the scanner unit10. The control section has a CPU, ROM, RAM, and the like. The control section plays a central role of the control for the multifunction apparatus1to realize a scanner function, a photocopy function, a printer function, and a facsimile function.

The facsimile section transmits the manuscript image read by the scanner unit10to the destination desired by a user via a network based on the control by the control section. Further, the facsimile section can receive facsimile data via the network. The control section controls the image formation section to print the received facsimile data on a sheet of printing paper or the like in a paper feed cassette7. That is, the multifunction apparatus1realizes the facsimile function by controlling the scanner unit10, the facsimile section, and the image formation section.

The image formation section prints the inputted image data onto the printing paper transported from the paper feed cassette7based on the control by the control section. The multifunction apparatus1controls the image formation section to process the image data corresponding to the image read by the scanner unit10, thereby realizing the photocopy function. Further, the multifunction apparatus1controls the image formation section to process the print data inputted via the network, thereby realizing the printer function.

Further, an operation panel5and a liquid crystal display6are provided on the upper surface on the front side of the main body2. The operation panel5is manipulated to input various instructions to the multifunction apparatus1. The liquid crystal display6displays various kinds of information about the multifunction apparatus1to inform the user of the contents of the information.

Further, the paper feed cassette7is installed to be insertable and removable through the front surface of the main body2. The paper feed cassette7accommodates sheets of the printing paper as a recording medium in a stacked state. The printing paper is used to print the image formed by the image formation section.

Then, the top cover3is provided to be openable and closeable with the rear-end edge of the upper surface of the main body2as the axis. When the top cover3is closed, the top cover3covers the upper surface of the main body2, i.e. the manuscript table11and the contact glass16. Therefore, the top cover3can fix the manuscript, which is set on the contact glass16, at that position.

Further, the top cover3has an auto document feeder4(ADF). The auto document feeder4is provided on the left side of the top cover3. The auto document feeder4feeds the manuscripts in a manuscript tray (not shown) one by one consecutively and, after transporting the manuscripts along a predetermined transport path, discharges the manuscripts to a paper discharge tray (not shown). The multifunction apparatus1can read the image of the manuscript in a manner in which the scanner unit10reads the image in the course of transporting the manuscript by the auto document feeder4.

Next, referring toFIG. 2, explanations will be made in detail with respect to a configuration of the scanner unit10of the multifunction apparatus1. As described above, the scanner unit10has the image sensor20, the first carriage30, the slide shaft25, the reading transport motor, the flat cable, and the like. The scanner unit10is provided below the contact glass16in the upper part of the main body2. Further, in the first embodiment, the portion, in the main body2, at which the scanner unit10is provided is parted by a seamier bottom surface17from a portion in which the facsimile section, the image formation section and the like are accommodated.

The image sensor20is configured by a so-called contact image sensor (CIS). The image sensor20reads the image of the manuscript positioned on the contact glass16. The image sensor20has a reading surface21including an imaging element and the like at its upper surface positioned on the side of the contact glass16. The image sensor20has a reading range with a length equivalent to the short side of the maximum manuscript size in the main scanning direction, i.e. the front-rear direction with respect to the main body2. Further, the image sensor20is formed to have an approximately cuboid shape and to extend in the main scanning direction. The image sensor20is contained in an aftermentioned sensor container31of the first carriage30.

As shown inFIG. 2, the slide shaft25is a shaft member having a circular rod form. The slide shaft25is provided over or above the scanner bottom surface17to extend toward the left and right directions of the main body2. The slide shaft25supports the image sensor20to be slidable in the left-right direction via the first carriage30. Then, based on the driving control by the control section, the reading transport motor can slide the image sensor20which is installed on the first carriage30along the slide shaft25via a driving force transmission mechanism such as a pulley belt mechanism and the like.

Then, in the multifunction apparatus1, the image sensor20is usually located in a so-called home position, i.e. a standby position S under the left end portion of the contact glass16. As shown inFIGS. 2 and 5, the image sensor20can slide along the lower surface of the contact glass16from the standby position S up to a position at a distance equivalent to the long side of the maximum manuscript size (to be referred to as “terminal position T” hereinbelow).

The image sensor20reads an image from the manuscript set on the contact glass16when the image sensor20is moved between the standby position S and the terminal position T along a secondary scanning direction parallel to the left-right direction of the multifunction apparatus1. Therefore, as shown inFIG. 1, the scanner unit10has the maximum reading range R corresponding to the maximum-sized manuscript and can read an image of any manuscript which is not larger than the maximum manuscript size.

Next, referring toFIGS. 3 to 5, explanations will be made in detail with respect to a configuration of the first carriage30supporting the image sensor20in the scanner unit10according to the first embodiment. As described above, the first carriage30supports the image sensor20from below and supports the image sensor20to be slidable along the slide shaft25in the secondary scanning direction.

As shown inFIGS. 3 and 4, the first carriage30includes the sensor container31, and spring attachment portions32. The first carriage30extends in the front-rear direction of the multifunction apparatus1. The sensor container31is formed to have a recess which is open to the contact glass16, and configured as a groove extending along the front-rear direction of the multifunction apparatus1. The sensor container31contains the image sensor20so that the reading surface21of the image sensor20faces upward, i.e. toward the contact glass16. The sensor container31supports the image sensor20from below.

The spring attachment portions32are formed on the end portions in the longitudinal direction of the first carriage30positioned on the front side of the multifunction apparatus1. The spring attachment portions32are configured to be capable of attachment of a holder member35and springs36. As shown inFIGS. 3 to 5, the spring attachment portions32are adjacent to the sensor container31and face each other in the secondary scanning direction of the multifunction apparatus1so that the sensor container31is sandwiched therebetween.

As shown inFIG. 4, the sensor container31has an opening31A on a side of an end portion of the first carriage30. The opening31A is formed to penetrate the bottom of the sensor container31which is positioned on the side of the end portion provided with the spring attachment portions32within a certain range, i.e. an area from the central portion up to the end portion side in the longitudinal direction. Therefore, the end portion of the image sensor20contained in the sensor container31is movable downward below the first carriage30via the opening31A.

As shown inFIGS. 4 and 5, the holder member35supports the image sensor20contained in the sensor container31from below. The holder member35holds the springs36between the holder member35and the spring attachment portions32. The holder member35has a sensor support portion35A, biased portions35B, and locking hooks35C.

As shown inFIG. 5, similar to the sensor container31, the sensor support portion35A is formed to have a recess which is open upward. The sensor support portion35A supports the lower surface of the image sensor20contained in the sensor container31. Further, under a condition that the holder member35is attached to the sensor container31, the sensor support portion35A traverses the opening31A in the secondary scanning direction at the position of forming the spring attachment portions32.

The biased portions35B are formed to extend horizontally in outward directions with respect to the sensor support portion35A from the two upper ends of the sensor support portion35A formed to have a recess which is open upward. The biased portions35B retain the end portions of the springs36attached to the spring attachment portions32, respectively. As shown inFIG. 5, under a condition that the holder member35is attached to the first carriage30, the biased portions35B are positioned above the spring attachment portions32, respectively. The biased portions35B are biased upward by the springs36attached to the spring attachment portions32, respectively.

Further, the locking hooks35C are hooks extending downward from the end edges of the respective biased portions35B positioned outside of the sensor support portion35A. The locking hooks35C have claw portions at the lower end portions to project toward outside, respectively. Then, by engagement with engagement holes31B formed in the first carriage30, the locking hooks35C fulfill the function of retaining the holder member35to prevent the holder member35from coming off the first carriage30.

As shown inFIG. 5, the engagement holes31B are formed by cutting away the lower portions of the side walls of the first carriage30on the left and right at the spring attachment portions32, respectively. Under a condition that the holder member35is attached to the first carriage30, the claw portions of the locking hooks35C enter into the engagement holes31B. Therefore, if the holder member35moves upward by the biasing force of the springs36, then the claw portions of the locking hooks35C come into contact with the upper ends of the engagement holes31B. By these contacts, the holder member35is retained in place without coming off the first carriage30, and thereby it is possible to prevent loss of the holder member35.

The springs36are provided between the biased portions35B of the holder member35and the spring attachment portions32, respectively. The upper ends of the springs36make contact with the lower surfaces of the biased portions35B. The lower ends of the springs36are retained on the spring attachment portions32. As shown inFIG. 5, the upper ends of the springs36are positioned below the contact glass16and above the lower surface of the image sensor20contained in the sensor container31. Further, the spring attachment portions32retaining the lower ends of the springs36are positioned above the lower surface of the image sensor20in the sensor container31. Therefore, between the biased portions35B of the holder member35and the spring attachment portions32, the springs36can bias the image sensor20along with the holder member35upward to the contact glass16.

As explained above, in the multifunction apparatus1of the first embodiment, on the side of the end portion of the first carriage30, the two biased portions35B constituting the holder member35are adjacent to the reading surface21of the image sensor20in the sensor container31in the left-right direction. Then, between the respective biased portions35B and spring attachment portions32, the springs36bias the biased portions35B of the holder member35upward. Here, the image sensor20is supported from below by the sensor support portion35A of the holder member35. Therefore, the image sensor20is biased toward the contact glass16by the biasing force of the springs36exerted on the biased portions35B of the holder member35.

Further, as shown inFIG. 3, when viewed from upside of the reading surface21of the image sensor20in the sensor container31, the biased portions of the present invention are adjacent to the reading surface21. That is, as long as this condition is satisfied, the biased portions may be positioned at any position in the up-down direction with respect to the reading surface21of the image sensor20. For example, as long as the above condition is satisfied, the biased portions may be positioned either above the reading surface21or below the reading surface21. Further, the biased portions may also be at the same height with the reading surface21.

As shown inFIGS. 3 to 5, in the first embodiment, the springs36are not ever positioned between the lower surface of the image sensor20and the sensor container31. Therefore, it is possible for the multifunction apparatus1to reduce the vertical dimension of the image sensor20and first carriage30. Further, the springs36bias the image sensor20to the contact glass16via the biased portions35B adjacent to the reading surface21of the image sensor20in the secondary scanning direction. Therefore, the multifunction apparatus1can utilize the space in the first carriage30adjacent to the sensor container31in the secondary scanning direction to bias the image sensor20toward the contact glass16. That is, it is possible for the multifunction apparatus1to facilitate miniaturization of the apparatus in the vertical direction and to bias the image sensor20toward the contact glass16.

Further, as shown inFIG. 5, the two biased portions35B of the holder member35are adjacent to the reading surface21of the image sensor20in the sensor container31in the left-right direction. The two biased portions35B are biased upward by the springs36. That is, according to the multifunction apparatus1, it is possible to balance the biasing force of the springs36for the image sensor20in the left-right direction. Therefore, it is possible to bias the reading surface21of the image sensor20toward the contact glass16in an appropriate state, i.e., being kept in a horizontal state.

Second Embodiment

Next, referring to the relevant figures, explanations will be made in detail with respect to a second embodiment. Further, a multifunction apparatus1according to the second embodiment basically has the same configuration with the multifunction apparatus1according to the first embodiment, but differs in the configurations of the carriage and the holder member of the scanner unit10. Hence, explanations will be omitted for the same configuration as in the first embodiment.

Referring toFIGS. 6 and 7, explanations will be made in detail with respect to configurations of a carriage (to be referred to as a “second carriage40” below) and a holder member45according to the second embodiment. Similar to the aforementioned first carriage30, the second carriage40supports the image sensor20from below and supports the image sensor20to be slidable along the slide shaft25in the secondary scanning direction.

As shown inFIGS. 6 and 7, the second carriage40includes a sensor container41, and a spring fitting portion42. The second carriage40extends in the front-rear direction of the multifunction apparatus1. The sensor container41has an opening41A. The sensor container41has the same configuration with the sensor container31of the first carriage30in the first embodiment. Accordingly, explanations will be omitted for the configurations of the sensor container41and the opening41A.

Further, the spring fitting portion42is formed in the end portion in the longitudinal direction of the second carriage40positioned on the front side of the multifunction apparatus1. The spring fitting portion42is configured to be capable of attachment of the holder member45and a spring46. As shown inFIG. 7, the spring fitting portion42is adjacent to the left side of the sensor container41in the secondary scanning direction of the multifunction apparatus1.

Similar to the first embodiment, the holder member45in the second embodiment supports the image sensor20contained in the sensor container41from below. The holder member45holds the spring46between the holder member45and the spring fitting portion42. Here, as shown inFIGS. 6 and 7, the holder member45has a sensor support portion45A, a biased portion45B, a locking hook45C, and a revolving retainment portion45D. Since the sensor support portion45A has the same configuration with the aforementioned sensor support portion35A of the first carriage30, the explanation of which will be omitted.

In the holder member45according to the second embodiment, the biased portion45B is formed to extend horizontally in an outward direction with respect to the sensor support portion45A from the left upper end of the sensor support portion45A formed to have a recess which is open upward. The biased portion45B retains the end portion of the spring46attached to the spring fitting portion42. As shown inFIG. 7, under a condition that the holder member45is attached to the second carriage40, the biased portion45B is positioned above the spring fitting portion42. The biased portion45B is biased upward by the spring46attached to the spring fitting portion42.

Further, the locking hook45C is a hook extending downward from the left end edge of the biased portion45B. The locking hook45C has a claw portion at the lower end portion to project toward outside. Then, by engagement with an engagement hole41B formed in the second carriage40, the locking hook45C fulfills the function of retaining the holder member45to prevent the holder member45from coming off the second carriage40.

As shown inFIG. 7, the revolving retainment portion45D is formed to extend in an outward direction with respect to the sensor support portion45A from the right upper end of the sensor support portion45A. The revolving retainment portion45D retains the holder member45so that the holder member45can revolve upward with respect to the second carriage40about the revolving retainment portion45D.

The spring46is provided between the biased portion45B of the holder member45and the spring fitting portion42. The upper end of the spring46makes contact with the lower surface of the biased portion45B. The lower end of the spring46is retained on the spring fitting portion42. As shown inFIG. 7, the upper end of the spring46is positioned below the contact glass16and above the lower surface of the image sensor20contained in the sensor container41. Further, the spring fitting portion42retaining the lower end of the spring46is positioned above the lower surface of the image sensor20in the sensor container41. Accordingly, between the biased portion45B of the holder member45and the spring fitting portion42, the spring46can bias the image sensor20upward along with the holder member45.

As explained above, in the multifunction apparatus1of the second embodiment, on the end portion side of the second carriage40, the biased portion45B of the holder member45is adjacent to left side of the reading surface21of the image sensor20in the sensor container41. Then, between the biased portion45B and spring fitting portion42, the spring46biases the biased portion45B of the holder member45upward. Further, the holder member45is retained so that the holder member45can revolve about the revolving retainment portion45D by the revolving retainment portion45D formed in the right-side portion of the sensor support portion45A. Here, the image sensor20is supported from below by the sensor support portion45A of the holder member45. Therefore, the image sensor20is biased toward the contact glass16by the biasing force of the spring46exerted on the biased portion45B of the holder member45.

As shown inFIG. 7, also in the second embodiment, the spring46is not positioned between the lower surface of the image sensor20and the sensor container41. Accordingly, it is possible for the multifunction apparatus1to reduce the vertical dimension of the image sensor20and second carriage40. Further, the spring46biases the image sensor20to the contact glass16via the biased portion45B adjacent to the reading surface21of the image sensor20in the secondary scanning direction. Accordingly, the multifunction apparatus1can utilize the space in the second carriage40adjacent to the sensor container41in the secondary scanning direction to bias the image sensor20toward the contact glass16. That is, it is possible for the multifunction apparatus1to facilitate miniaturization of the apparatus in the vertical direction and to bias the image sensor20toward the contact glass16.

Third Embodiment

Next, referring to the relevant figures, explanations will be made in detail with respect to a third embodiment. Further, a multifunction apparatus1according to the third embodiment basically has the same configuration with the multifunction apparatus1according to the first embodiment or the second embodiment, but differs in the configurations of the carriage and the holder member of the scanner unit10. Hence, explanations will be made only for those differences in reference to the relevant figures, but omitted for the same configuration as in the first embodiment or the second embodiment.

Referring toFIG. 8and the like, explanations will be made in detail with respect to configurations of a carriage (to be referred to as a “third carriage50” below), a first holder member55and a second holder member56according to the third embodiment. Similar to the aforementioned first carriage30and second carriage40, the third carriage50supports the image sensor20from below and supports the image sensor20to be slidable along the slide shaft25in the secondary scanning direction.

As shown inFIG. 8, the third carriage50includes a sensor container51, first spring attachment portions52, and second spring attachment portions53. The third carriage50extends in the front-rear direction of the multifunction apparatus1. Further, the sensor container51has the same configuration with the sensor container31of the first carriage30in the first embodiment. Accordingly, explanations will be omitted for the configuration of the sensor container51.

Further, the first spring attachment portions52are formed on one end portion in the longitudinal direction of the third carriage50positioned on the front side of the multifunction apparatus1. The first spring attachment portions52are configured to be capable of attachment of the first holder member55and springs57. As shown inFIG. 8, the first spring attachment portions52are adjacent to the sensor container51and face each other in the secondary scanning direction of the multifunction apparatus1so that the sensor container51is sandwiched therebetween.

Further, the second spring attachment portions53are formed on the other end portion in the longitudinal direction of the third carriage50positioned on the rear side of the multifunction apparatus I. The second spring attachment portions53are configured to be capable of attachment of the second holder member56and other springs57. As shown inFIG. 8, the second spring attachment portions53are adjacent to the sensor container51and face each other in the secondary scanning direction of the multifunction apparatus1so that the sensor container51is sandwiched therebetween.

In the third embodiment, the first holder member55and the second holder member56support the image sensor20contained in the sensor container51from below on both end portions in the longitudinal direction of the image sensor20, respectively. The first holder member55holds the springs57between the first spring attachment portions52and the first holder member55and the second holder member56holds the springs57between the second spring attachment portions53and the second holder member56.

Similar to the holder member35according to the first embodiment, the first holder member55has a sensor support portion, biased portions55A, and locking hooks. Further, also similar to the holder member35according to the first embodiment, the second holder member56has a sensor support portion, biased portions56A, and locking hooks.

Since the first holder member55and the second holder member56have the same configuration with the aforementioned holder member35according to the first embodiment, their explanations will be omitted. Further, the aspect of attachment of the first holder member55to the first spring attachment portions52, as well as the aspect of attachment of the second holder member56to the second spring attachment portions53, is the same as that of the attachment of the holder member35to the spring attachment portions32as explained in the first embodiment in reference toFIG. 5. Therefore, the explanations for those aspects will also be omitted.

As explained above, in the multifunction apparatus1of the third embodiment, on both end portion sides in the main scanning direction of the third carriage50, the biased portions55A of the first holder member55and the biased portions56A of the second holder member56are adjacent to the reading surface21of the image sensor20in the sensor container51in the left-right direction. Then, between the respective biased portions55A and first spring attachment portions52, the springs57bias the biased portions55A of the first holder member55upward. Further, between the respective biased portions56A and second spring attachment portions53, the other springs57bias the biased portions56A of the second holder member56upward.

Here, the image sensor20is supported from below by the sensor support portions of the first holder member55and the second holder member56. Accordingly, the image sensor20is biased toward the contact glass16by the biasing force of the springs57exerted on the first holder member55and the second holder member56. That is, in the third embodiment, in both end portions of the image sensor20in the main scanning direction, the biasing force of the springs57is exerted on the image sensor20via the first holder member55and the second holder member56. Therefore, it is possible for the multifunction apparatus1to bias the image sensor20toward the contact glass16in the optimum state, i.e., being kept in a horizontal state with respect to the main scanning direction of the image sensor20.

In the third embodiment, the springs57are not positioned between the lower surface of the image sensor20and the sensor container51. Accordingly, it is possible for the multifunction apparatus1to reduce the vertical dimension of the image sensor20and third carriage50. Further, the springs57bias the image sensor20to the contact glass16via the biased portions55A and biased portions56A adjacent to the reading surface21of the image sensor20in the secondary scanning direction. Accordingly, the multifunction apparatus1can utilize the space in the third carriage50adjacent to the sensor container51in the secondary scanning direction to bias the image sensor20toward the contact glass16. That is, it is possible for the multifunction apparatus1to facilitate miniaturization of the apparatus in the vertical direction while biasing the image sensor20toward the contact glass16.

Further, as shown inFIG. 8, the two biased portions55A of the first holder member55and the two biased portions56A of the second holder member56are adjacent to the reading surface21of the image sensor20in the sensor container51in the left-right direction, respectively. The two biased portions55A and the two biased portions56A are biased upward by the springs57, respectively. That is, according to the multifunction apparatus1, it is possible to balance the biasing force of the springs57for the image sensor20in the left-right direction. Accordingly, it is possible to bias the reading surface21of the image sensor20toward the contact glass16in an appropriate state, i.e., being kept in a horizontal state also with respect to the secondary scanning direction.

Fourth Embodiment

Next, referring to the relevant figures, explanations will be made in detail with respect to a fourth embodiment. A multifunction apparatus1according to the fourth embodiment basically has the same configuration with the multifunction apparatus1according to any of the first embodiment to the third embodiment, but differs in the configurations of the carriage and the holder member of the scanner unit10. Hence, explanations will be made only for those differences in reference to the relevant figures, but omitted for the same configuration as in any of the first embodiment to the third embodiment.

Referring toFIG. 9and the like, explanations will be made in detail with respect to configurations of a carriage (to be referred to as a “fourth carriage60” below) and a holder member65according to the fourth embodiment. Similar to the aforementioned first carriage30, second carriage40and third carriage50, the fourth carriage60supports the image sensor20from below. The fourth carriage60supports the image sensor20to be slidable along the slide shaft25in the secondary scanning direction.

As shown inFIG. 9, the fourth carriage60includes a sensor container61and spring attachment portions62. The fourth carriage60extends in the front-rear direction of the multifunction apparatus1. Further, the sensor container61has the same configuration with the sensor container31of the first carriage30in the first embodiment. Accordingly, explanations will be omitted for the configuration of the sensor container61.

Further, the spring attachment portions62are formed in the central portion in the longitudinal direction of the fourth carriage60. The spring attachment portions62are configured to be capable of attachment of the holder member65and springs66. As shown inFIG. 9, the spring attachment portions62are adjacent to the sensor container61and face each other in the secondary scanning direction of the multifunction apparatus1so that the sensor container61is sandwiched therebetween.

In the fourth embodiment, the holder member65supports the image sensor20contained in the sensor container61from below on the central portion in the longitudinal direction of the image sensor20. The holder member65holds the springs66between the holder member65and the spring attachment portions62. Similar to the holder member35according to the first embodiment, the holder member65has a sensor support portion, biased portions65A, and locking hooks.

Since the holder member65has the same configuration with the aforementioned holder member35according to the first embodiment, the explanation of which will be omitted. Further, the aspect of attachment of the holder member65to the spring attachment portions62is the same as that of attachment of the holder member35in the first embodiment. Therefore, the explanation for that aspect will also be omitted.

As explained above, in the multifunction apparatus1of the fourth embodiment, in the central portion in the main scanning direction of the fourth carriage60, the biased portions65A of the holder member65are adjacent to the reading surface21of the image sensor20in the sensor container61in the left-right direction. Then, between the respective biased portions65A and spring attachment portions62, the springs66bias the biased portions65A of the holder member65upward. The image sensor20is supported from below by the sensor support portion of the holder member65. Accordingly, the image sensor20is biased toward the contact glass16by the biasing force of the springs66exerted on the holder member65. That is, in the fourth embodiment, in the central portion in the main scanning direction of the image sensor20, the biasing force of the springs66is exerted on the image sensor20via the holder member65. Therefore, it is possible for the multifunction apparatus1with a small number of components to bias the image sensor20toward the contact glass16while keeping the same in a comparatively horizontal state.

Also in the fourth embodiment, the springs66are not positioned between the lower surface of the image sensor20and the sensor container61. Accordingly, it is possible for the multifunction apparatus I to reduce the vertical dimension of the image sensor20and fourth carriage60. Further, the springs66bias the image sensor20to the contact glass16via the biased portions65A adjacent to the reading surface21of the image sensor20in the secondary scanning direction. Accordingly, the multifunction apparatus1can utilize the space in the fourth carriage60adjacent to the sensor container61in the secondary scanning direction to bias the image sensor20toward the contact glass16. That is, it is possible for the multifunction apparatus1to facilitate miniaturization of the apparatus in the vertical direction and to bias the image sensor20toward the contact glass16.

Further, as shown inFIG. 9, the two biased portions65A of the holder member65are adjacent to the reading surface21of the image sensor20in the sensor container61in the left-right direction. The two biased portions65A are biased upward by the springs66. That is, according to the multifunction apparatus1, it is possible to balance the biasing force of the springs66for the image sensor20in the left-right direction. Accordingly, it is possible to bias the reading surface21of the image sensor20toward the contact glass16in an appropriate state, i.e., being kept in a horizontal state with respect to the secondary scanning direction.

Fifth Embodiment

Next, referring to the relevant figures, explanations will be made in detail with respect to a fifth embodiment. A multifunction apparatus1according to the fifth embodiment basically has the same configuration with the multifunction apparatus1according to any of the first embodiment to the fourth embodiment, but differs in the configurations of the carriage and the holder member of the scanner unit10. Hence, explanations will be made only for those differences in reference to the relevant figures, but omitted for the same configuration as in any of the first embodiment to the fourth embodiment.

Referring toFIGS. 10 and 11, explanations will be made in detail with respect to configurations of a carriage (to be referred to as a “fifth carriage70” below) and a holder member75according to the fifth embodiment. Similar to the aforementioned first carriage30; the fifth carriage70supports the image sensor20from below. The fifth carriage70supports the image sensor20to be slidable along the slide shaft25in the secondary scanning direction.

As shown inFIGS. 10 and 11, the fifth carriage70includes a sensor container71and spring attachment portions72. The fifth carriage70extends in the front-rear direction of the multifunction apparatus1. The sensor container71has an opening71A and engagement holes71B. The sensor container71has the same configuration with the sensor container31of the first carriage30in the first embodiment. Accordingly, explanations will be omitted for the configuration of the sensor container71.

Further, the spring attachment portions72are formed in an end portion in the longitudinal direction of the fifth carriage70positioned on the front side of the multifunction apparatus1. The spring attachment portions72are configured to be capable of attachment of the holder member75and springs76. As shown inFIGS. 10 and 11, the spring attachment portions72are adjacent to the sensor container71and face each other in the secondary scanning direction of the multifunction apparatus1so that the sensor container71is sandwiched therebetween.

In the fifth embodiment, the holder member75supports the image sensor20contained in the sensor container71from below in the front end portion in the longitudinal direction of the image sensor20. The holder member75holds the springs76between the holder member75and the spring attachment portions72. As shown inFIG. 11, the holder member75has a sensor support portion75A, biased portions75B, locking hooks75C, and spacer ribs75D.

Since the sensor support portion75A, the biased portions75B and the locking hooks75C of the holder member75have the same configurations with the sensor support portion35A, the biased portions35B and the locking hooks35C of the aforementioned holder member35according to the first embodiment, respectively, their explanations will be omitted. Further, the aspect of attachment of the holder member75to the spring attachment portions72is the same as that of attachment of the holder member35in the first embodiment. Accordingly, the explanation for that aspect will also be omitted.

As shown inFIGS. 10 and 11, the spacer ribs75D are ribs which projects upward to the contact glass16on the upper surfaces of the biased portions75B. If the holder member75moves upward due to the biasing force of the springs76, then the upper ends of the spacer ribs75D come into contact with the lower surface of the contact glass16. That is, according to the multifunction apparatus1of the fifth embodiment, by virtue of the spacer ribs75D, it is possible to keep a distance between the reading surface21of the image sensor20retained by the holder member75and the lower surface of the contact glass16constantly, based on the projection amount of the spacer ribs75D. As a result, the multifunction apparatus1can properly maintain the distance between the reading surface21of the image sensor20and a manuscript on the contact glass16, and thereby it is possible to maintain the reading quality of the scanner unit10.

The springs76are provided between the biased portions75B of the holder member75and the spring attachment portions72, respectively. The upper ends of the springs76make contact with the lower surfaces of the biased portions75B. The lower ends of the springs76are retained on the spring attachment portions72. As shown inFIG. 11, the upper ends of the springs76are positioned below the contact glass16and above the lower surface of the image sensor20contained in the sensor container71. Further, the spring attachment portions72retaining the lower ends of the springs76are positioned above the lower surface of the image sensor20in the sensor container71. Accordingly, between the biased portions75B of the holder member75and the spring attachment portions72, the springs76can bias the image sensor20upward along with the holder member75.

As explained above, in the multifunction apparatus1of the fifth embodiment, on the end portion side of the fifth carriage70, the two biased portions75B constituting the holder member75are adjacent to the reading surface21of the image sensor20in the sensor container71in the left-right direction. Then, between the respective biased portions75B and spring attachment portions72, the springs76bias the biased portions75B of the holder member75upward. Here, the image sensor20is supported from below by the sensor support portion75A of the holder member75. Accordingly, the image sensor20is biased toward the contact glass16by the biasing force of the springs76exerted on the biased portions75B of the holder member75.

As shown inFIG. 11, in the fifth embodiment, the springs76are not positioned between the lower surface of the image sensor20and the sensor container71. Therefore, it is possible for the multifunction apparatus1to reduce the vertical dimension of the image sensor20and fifth carriage70. Further, the springs76bias the image sensor20to the contact glass16via the biased portions75B adjacent to the reading surface21of the image sensor20in the secondary scanning direction. Therefore, the multifunction apparatus1can utilize the space in the fifth carriage70adjacent to the sensor container71in the secondary scanning direction to bias the image sensor20toward the contact glass16. That is, it is possible for the multifunction apparatus1to facilitate miniaturization of the apparatus in the vertical direction and to bias the image sensor20toward the contact glass16.

Further, as shown inFIGS. 10 and 11, the two biased portions75B of the holder member75are adjacent to the reading surface21of the image sensor20in the sensor container71in the left-right direction. The two biased portions75B are biased upward by the springs76. Further, the biased portions75B have the spacer ribs75D on their upper surfaces, respectively. Therefore, according to the multifunction apparatus1, it is possible to balance the biasing force of the springs76for the image sensor20in the left-right direction. Further, by virtue of the spacer ribs75D, it is possible for the multifunction apparatus1to keep a distance between the reading surface21of the image sensor20and the lower surface of the contact glass16constantly. Accordingly, it is possible to bias the reading surface21of the image sensor20toward the contact glass16in an appropriate state, i.e., being kept in a horizontal state.

In the fifth embodiment, the holder member75is attached to the front end portion of the fifth carriage70and the spacer ribs75D are provided on the upper surfaces of the biased portions75B of the holder member75. However, a spacer rib may also be provided on the upper surface of the biased portion45B of the holder member45in the second embodiment. Further, spacer ribs may also be provided on the upper surfaces of the biased portions55A of the first holder member55and the biased portions56A of the second holder member56in the third embodiment, respectively. Furthermore, spacer ribs may also be provided on the upper surfaces of the biased portions65A of the holder member65in the fourth embodiment. In any of these cases, by virtue of the spacer ribs, it is possible to maintain a distance between the reading surface21of the image sensor20and the lower surface of the contact glass16constantly.

Based on the embodiments, the present invention was described hereinabove. However, the present invention is not limited to the embodiments described above, but can undergo various modifications and changes without departing from the gist and scope of the present invention. For example, in the above embodiments, an example is shown by the multifunction apparatus1having a scanner function, a photocopy function, a printer function, and a facsimile function. However, the present invention is not limited to this aspect. It is possible to apply the present invention to any scanner apparatuses or photocopy machines which at least have a scanner unit of the flatbed type.

Further, in the above embodiments, the biased portions are positioned to be adjacent to the reading surface of the image sensor in the secondary scanning direction. However, the present invention is not limited to this aspect. That is, the biased portions may alternatively be positioned to be adjacent to the reading surface of the image sensor in the main scanning direction.

Further, in the above embodiments, the biased portions of the holder member are biased upward by the springs so as to bias the image sensor supported by the holder member toward the contact glass. However, the present invention is not limited to this aspect. For example, in the upper portions of side surfaces of the image sensor, biased portions may be formed to extend horizontally in outward directions from the image sensor. In this case, by exerting the biasing force of the springs on the biased portions formed integrally with the image sensor, the image sensor may also be biased toward the contact glass.

That is, the biased portions of the present invention may be members which receive the biasing force of a biasing member at a position adjacent to the reading surface of the image sensor, and which exert the biasing force to bias the image sensor toward the contact glass. Accordingly, as described above, the biased portions of the present invention include those formed integrally with the image sensor. Further, as in each of the embodiments described above, it is a matter of course that the biased portions also include those formed in another members separate from the image sensor.

In the above embodiments, the spring attachment portions are formed in the end portion(s) or the central portion in the longitudinal direction of the carriage so as to attach the holder member and the springs. By virtue of this configuration, the image sensor20is biased toward the contact glass16. However, the present invention is not limited to this aspect. For example, it may alternatively be configured that the image sensor20is biased toward the contact glass16by forming the spring attachment portions in both end portions and the central portion in the longitudinal direction of the carriage to attach the holder members and the springs in those three portions.