Patent Application
20140153936
The present invention relates to an image forming apparatus, such as a copying machine, a printer or a facsimile machine, having a function of forming an image on a recording material such as a sheet, and relates to a cartridge detachably mountable to the image forming apparatus.
An electrophotographic image forming apparatus forms the image on the recording material by an electrophotographic image forming process using a photosensitive drum and a transfer roller. In a constitution of an image forming portion for forming the image on the recording material, a process cartridge type in which a photosensitive member and process means actable on the photosensitive member are integrally assembled into a cartridge which is detachably mountable to an image forming apparatus main assembly is employed. According to the process cartridge type, maintenance of the image forming apparatus can be performed by a user himself (herself) irrespective of a service person, and therefore it is possible to remarkably improve operativity (operability). For this reason, the process cartridge type has been widely used in the image forming apparatus.
In the process cartridge type, when the process cartridge is demounted from and mounted into the image forming apparatus main assembly, it is desired that operativity of the cartridge is facilitated. In a conventional constitution, as one of means for facilitating the operativity, when the process cartridge is mounted into the image forming apparatus main assembly, complete mounting of the process cartridge into the apparatus main assembly is detected. That is, a constitution in which the process cartridge is electrically connected with an electrical contact when the process cartridge reaches a mounting position thereof is employed, and the electrical contact is connected with a mounting detecting means, provided in the image forming apparatus main assembly, for detecting presence or absence of the process cartridge (Japanese Laid-Open Patent Application (JP-A) 2000-194246).
However, in the above-described conventional constitution, there was the following problem.
There is a possibility that when the cartridge is mounted into the apparatus main assembly, friction generated between the apparatus main assembly and the cartridge and a spring provided in an apparatus main assembly side in order to determine a position of the cartridge constitute a resistance during insertion of the cartridge.
Further, in the case where a mounting locus of the cartridge is not a rectilinear line due to constrains such as a space and position of the cartridge in the apparatus main assembly, an inserting direction of the cartridge is changed in partway. In these constitutions, when an operator mounted the cartridge into the apparatus main assembly, there was a possibility that the cartridge was placed in an incompletely mounted state in which the cartridge is not completely mounted in a positioning portion in the apparatus main assembly.
The present invention is accomplished for solving the above-described problem. A principal object of the present invention is to provide an image forming apparatus having improved usability during demounting and mounting and during exchanging of the cartridge by detecting an incompletely mounted state of the cartridge.
According to an aspect of the present invention, there is provided an image forming apparatus to which a cartridge including a first cartridge contact and a second cartridge contact is detachably mountable, comprising: a guiding member for guiding the cartridge to a positioning portion provided in a main assembly of the image forming apparatus; a first main assembly contact contactable to the first cartridge contact when the cartridge is positioned partway toward the positioning portion and is positioned in the positioning portion; a second main assembly contact contactable to the second cartridge contact when the cartridge is positioned partway toward the positioning portion; a third main assembly contact contactable to the second cartridge contact only when the cartridge is positioned in the positioning portion; and detecting means for detecting presence or absence of the cartridge in the main assembly and a mounted state of the cartridge by being electrically connected with the first, second and third main assembly contacts.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
Parts (a) to (c) of
Parts (a) to (c) of
Parts (a) and (b) of
Parts (a) to (d) of
Parts (a) to (d) of
With reference to the drawings, preferred embodiments of the present invention will be specifically described below. However, dimensions, materials, shapes and relative arrangement of constituent elements described in the following embodiments should be appropriately changed depending on structure and various conditions of devices (apparatuses) to which the present invention is to be applied, and therefore the scope of the present invention is not intended to be limited to the following embodiments.
An image forming apparatus according to First Embodiment of the present invention will be described. Incidentally, in this embodiment, as the image forming apparatus, a laser beam printer to which a process cartridge is detachably mountable is exemplified.
The image forming portion 20 includes a cartridge 1 which is detachably mountable to an apparatus main assembly 100A of the image forming apparatus 100 and which performs a part of an image forming process, a transfer roller 21 for transferring an image onto a recording material P, a laser exposure device 22 for irradiating a photosensitive member with laser light, a fixing device 23 for heat-fixing the recording material P, and the like.
The cartridge 1 includes a photosensitive drum 2 (photosensitive member) on which an electrostatic latent image is to be formed by being irradiated with laser light L from the laser exposure device 22. Further, the cartridge 1 includes a developing means for developing the electrostatic latent image on the photosensitive drum 2, a cleaning member 4 for removing a developer from the photosensitive drum 2, and a charging means 5 for electrically charging the photosensitive drum 2. Further, the photosensitive drum 2 carries a toner image developed from the electrostatic latent image by the developing means 3.
The feeding portion 10 includes a feeding roller 12 and a separating pad 11 which are used for separating and feeding sheets of the recording material P, one by one, accommodated in a feeding tray 13. The recording material P fed by the feeding portion 10 is sent to the image forming portion 20 by conveying rollers 25 and 26 held by a conveying frame 24, and in the image forming portion 20, the toner image formed on the photosensitive drum 2 is transferred by the transfer roller 21.
The recording material P having finished the transfer of the toner image is conveyed to a fixing device 23 constituted by a heating unit 27 and a pressing roller 28, and in the fixing device 23, the transferred toner image is heated and fixed. Thereafter, the recording material P is discharged to the discharge portion 30, constituted by a discharge tray 33 and an extended discharge tray 34, by discharging rollers 31 and 32.
Further, on the surface of the cartridge 1 in the L end side, an electrical contact 7a located close to the boss 1a and an electrical contact 6b (cartridge-side electrical contact) located close to the boss 1b are provided. Further, the electrical contacts 6a and 6b are electrically contacted to associated electrical contacts (described later) in an apparatus main assembly 100A side depending on a mounted state of the cartridge 1 to establish (electrical) continuity.
Further, at an end portion of the photosensitive drum 2 provided in the cartridge 1, a drum gear 7 for rotationally driving the photosensitive drum 2 is fixed. Further, the cartridge is provided with a grip portion for facilitating demounting and mounting of the cartridge 1 is provided, and is gripped to perform the demounting and mounting of the cartridge 1.
Parts (a) to (c) of
Part (a) of
Left and right side plates of the apparatus main assembly 100A is provided with a cartridge guide 103a (guide passage) for guiding the boss 1a of the cartridge 1 into the completely mounted state and a cartridge guide 103b (guide passage) for guiding the boss 1b of the cartridge 1 into the completely mounted state are provided, respectively. Further, at a deepest portion of the cartridge guide 103a, a positioning portion 103a1 to be engaged with the boss 1a when the cartridge 1 is completely mounted into the apparatus main assembly 100A is provided. Further, at a deepest portion of the cartridge guide 103b, a main assembly rotation-limiting portion 103b1 to be contacted to the boss 1b when the cartridge 1 is completely mounted into the apparatus main assembly 100A is provided.
When the cartridge 1 is inserted toward an inside of the apparatus main assembly 100A through an opening 110, the bosses 1a and 1b are moved along the cartridge guides 103a and 103b to contact the positioning portion 103a1 and the main assembly rotation-limiting portion 103b1, respectively. Accordingly, movement locus and attitude of the cartridge 1 in the apparatus main assembly 100A are determined by shapes of the cartridge guides 103a and 103b.
Further, as shown in (c) of
In an intermediate position of the cartridge guide 103b when the cartridge 1 is mounted into the apparatus main assembly 100A, a wire spring 104 as an urging means for bringing the boss 1b into contact with the main assembly rotation-limiting portion 103b1 is provided. The wire spring 104 urges the boss 1b so as not to be demounted from a mounting position in the completely mounted state of the cartridge 1. However, when the cartridge 1 is inserted into the apparatus main assembly 100A, the wire spring 104 constitutes an obstacle to the insertion of the boss 1b, and therefore the boss 1b is liable to stop in an incompletely mounted position where the boss 1b contacts the wire spring 104 toward the opening 110.
Further, a shape of the cartridge guide 103a is not a straight shape but is bent in partway of the mounting of the cartridge 1. For that reason, also an insertion direction of the cartridge 1 is changed in partway, so that the boss 1a is liable to stop in an incompletely mounted position 103a2. Accordingly, the boss 1a stops in the incompletely mounted position 103a2 and the boss 1b stops in the incompletely mounted position 103b2, so that the cartridge 1 is placed in the incompletely mounted state in some cases as shown in (b) of
In the end side of the side plate of the apparatus main assembly 100A, electrical contacts 102a and 102b (apparatus main assembly-side electrical contact) disposed so as to electrically contact the cartridge 1-side electrical contacts 6a and 6b, respectively, and an electrical contact 102c (apparatus main assembly-side electrical contact) are provided.
Next, connection of the cartridge 1-side electrical contacts with the apparatus main assembly 100A-side electrical contacts in the mounted state of the cartridge 1 will be described.
In the completely mounted state shown in (c) of
In the incompletely mounted state shown in (b) of
Further, when the cartridge 1-side electrical contact 6b is located between the apparatus main assembly 100A-side electrical contacts 102b and 102c, the wire spring 104 is disposed so as to urge the boss 1b toward the apparatus main assembly rotation-limiting portion 103b1. For that reason, the cartridge 1 is prevented from stopping in a position the incompletely mounted state (position) and the completely mounted state (position).
Parts (a) to (c) of
Part (a) of
In this embodiment, as a cartridge mounting detecting system (mounted state-detecting means) for detecting the mounted state of the cartridge 1, a circuit for detecting the mounted state of the cartridge 1 is provided in the apparatus main assembly 100A.
The detecting circuit is, as shown in
The current detecting portion 105 detects a current passing through the circuit and sends a detection result to a controller (not shown) of the apparatus main assembly 100A. Specifically, e.g., the resistor is provided in series in the circuit and then the current is measured by reading voltage drop of the resistor by an AD converter or a comparator, so that a measured current value is set to the controller.
In the cartridge 1 side, the electrical contacts 6a and 6b are provided and are electrically connected with each other inside the cartridge 1.
In the case where the cartridge 1 is in the unmounted state, as shown in (a) of
In the case where the cartridge 1 is in the incompletely mounted state, as shown in (b) of
On the other hand, in the case where the cartridge 1 is in the completely mounted state, as shown in (c) of
As described above, the detection of the mounted state of the cartridge 1 is made by detecting the value of the current passing through the current detecting portion 105, so that it becomes possible to discriminate whether the mounted state of the cartridge 1 is the unmounted state, the incompletely mounted state or the completely mounted state.
Incidentally, in this embodiment, the reason why a difference in voltage value is not detected but a difference in current value is detected is as follows. That is, in the image forming apparatus 100, the photosensitive drum 2 is electrically charged to a high voltage by the charging means 5, so that there is a high possibility that static electricity is generated also in many places in the image forming apparatus 100. If a constitution in which the voltage value is measured is employed, there is a possibility that the detecting circuit causes malfunction by the static electricity. The static electricity is high in voltage but is slight in current. Therefore, in this embodiment, a constitution in which the current is measured and thus the detecting circuit is not readily influenced by the static electricity is employed.
When the cartridge 1 is in the unmounted state or the incompletely mounted state, the controller (process executing means) of the image forming apparatus 100 displays warning to the user.
When the cartridge 1 is in the unmounted state or the incompletely mounted state, warning is displayed on a displaying portion provided on an operating panel 200 (
For example, in the case where the unmounting of the cartridge 1 is detected, a message to the effect that there is no cartridge and that the mounting of the cartridge 1 is urged is displayed. Further, in the case where the incompletely mounted state of the cartridge 1 is detected, a message to the effect that the cartridge 1 is not completely mounted and that strong pushing-in of the cartridge is urged is displayed.
In this way, the mounted state of the cartridge is displayed on the operating panel 200, and therefore it is possible to avoid a status in which the user does not aware of the incompletely mounted state of the cartridge 1 and discriminates that the image forming apparatus 100 causes malfunction.
Incidentally, without displaying the warning on the operating panel 200 by using the message, a light-emitting diode for the warning may also be turned on.
Further, a signal may also be sent to an external computer to display a message, on the basis of the signal, on a monitor of the computer.
Other constitutions in this embodiment will be described. In this embodiment, the electrical contact 102a and the current detecting portion 105 which are connectable in both of the incompletely mounted state and the completely mounted state are provided in the apparatus main assembly 100A side but may also be provided in the cartridge 1 side.
Further, in this embodiment, the electrical contacts 6a and 6b disposed in the cartridge 1 side are provided as two parts (components) on the cartridge 1 and are connected by the circuit, but an elongated electrical contact can also be provided as a single part in order to reduce the number of parts. Further, this electrical contact may also be disposed so as to connect between the apparatus main assembly-side electrical contacts 102a and 102b and between the apparatus main assembly-side electrical contacts 102 and 102c.
Further, in this embodiment, the electrical contacts 6a and 6b are provided at the longitudinal end of the cartridge 1, and the apparatus main assembly-side electrical contacts 102a, 102b and 102c are provided in the side of the side plate of the apparatus main assembly 100A. However, the electrical contacts are provided at the longitudinal ends (both ends) of the cartridge 1 and in the sides of the (both) side plates of the apparatus main assembly 100A, so that it becomes possible to detect the mounted state of the cartridge 1 at the longitudinal ends (both ends) of the cartridge 1.
Further, in this embodiment, an example of the case where a single cartridge 1 is provided is described, but even in the case where a plurality of cartridges are provided, by applying the present invention in a similar manner, it is possible to obtain a similar effect with respect to each of the cartridges.
Second Embodiment of the image forming apparatus according to the present invention will be described. In this embodiment, an operation after the detection of the incompletely mounted state is different from the operation in First Embodiment. Incidentally, constituent portions (elements) identical or similar to those in First Embodiment are represented by the same reference numerals or symbols and will be omitted from redundant description.
Parts (a) and (b) of
In each of these figures, a cross section is a plane which is perpendicular to the longitudinal direction of the cartridge 1 and which passes through a central portion of the apparatus main assembly 100A.
Part (a) of
A lever 106 (moving means), shown in
Therefore, when the cartridge 1 is placed in the incompletely mounted state, it becomes possible to move the cartridge 1 to the completely mounted state (position) without troubling the user. Further, when the incompletely mounted state of the cartridge 1 is detected, the lever 106 is moved to an initial position shown in (a) of
As a result, the lever 106 is operated only when the cartridge 1 is in the incompletely mounted state, so that an unnecessary operation of the lever 106 in the unmounted state and the incompletely mounted state of the cartridge 1 is avoided.
Incidentally, it is also possible to combine the lever 106 with First Embodiment. That is, on the operation panel 200 in First Embodiment, a message that the cartridge is in the incompletely mounted state and is moved to the completely mounted state (position) may also be displayed.
Third Embodiment of the image forming apparatus according to the present invention will be described. In this embodiment, constitutions of the cartridge guide, the electrical contacts and the detecting system are different from those in First Embodiment. Incidentally, constituent portions (elements) identical or similar to those in First Embodiment are represented by the same reference numerals or symbols and will be omitted from redundant description.
Parts (a) to (d) of
Part (a) of
In this embodiment, as shown in
The cartridge 1 is inserted into the apparatus main assembly 100A through an opening 110. Then, the cartridge guides 103a and 103b are formed so that the cartridge 1 is lowered by the self weight thereof to naturally move the bosses 1a and 1b to incompletely mounted positions 103a3 and 103b3, respectively.
For this reason, as shown in (b) of
Further, as shown in (c) of
In this embodiment, the electrical contact 6a close to the boss 1a and the cartridge 1 and the electrical contact 6b close to the boss 1b of the cartridge 1 are different from those in First Embodiment, and an electrical contact 6c is further provided. As shown in
In this embodiment, on one side plate of the apparatus main assembly 100A, electrical contacts 102d, 102e, 102f (apparatus main assembly-side electrical contact), 102g (apparatus main assembly-side electrical contact) and 102h are provided. Further, on the cartridge 1, the electrical contact 6a, 6b and 6c are disposed.
Next, connection of the cartridge 1-side electrical contacts with the apparatus main assembly-side electrical contacts in the mounted state of the cartridge 1 will be described.
In the completely mounted state shown in (d) of
In the first incompletely mounted state shown in (c) of
In the second incompletely mounted state shown in (b) of
Further, the cartridge 1 is inserted into the apparatus main assembly 100A and passes through the bent portions of the cartridge guides 103a and 103b. Thereafter, the cartridge 1-side electrical contact 6a and the apparatus main assembly 100A-side electrical contact 102d, and the cartridge 1-side electrical contact 6c and the apparatus main assembly 100A-side electrical contact 102h are disposed so as to be continuously electrically contacted to each other.
For this reason, after the cartridge 1 passes through the bent portions, the cartridge 1-side electrical contact 6b is contacted to the apparatus main assembly 100A-side electrical contacts 102g, 102f and 102e. As a result, it is possible to detect whether the cartridge 1 is placed in which state of the first incompletely mounted state, the second incompletely mounted state and the completely mounted state.
Parts (a) to (d) of
Part (a) of
In this embodiment, as a detecting system as a mounted state-detecting means for the cartridge 1, a circuit for detecting the mounted state of the cartridge 1 is provided in the apparatus main assembly 100A.
The detecting circuit is, as shown in
For this reason, a detected current value is different between the case where the respective electrical contacts are connected in the completely mounted state of the cartridge 1, the case where the respective electrical contacts are connected in the second incompletely mounted state of the cartridge 1, and the case where the respective electrical contacts are connected in the first incompletely mounted state of the cartridge 1.
In the cartridge 1 side, the electrical contacts 6a, 6b and 6c are provided and are electrically connected with each other inside the cartridge 1. Further, the electrical contact 6a is connected with the photosensitive drum 2. That is, in this embodiment, as one of the electrical contacts in the cartridge 1 side, an electrode for grounding the photosensitive drum 2 is used.
In the case where the cartridge 1 is in the unmounted state, as shown in (a) of
In the case where the cartridge 1 is in the second incompletely mounted state, as shown in (b) of
Further, in the case where the cartridge 1 is in the first incompletely mounted state, as shown in (c) of
On the other hand, in the case where the cartridge 1 is in the completely mounted state, as shown in (d) of
A notifying means for notifying the state of the cartridge 1 to the user is provided. When the cartridge 1 is in the unmounted state or the incompletely mounted state, the notifying means notifies the state of the cartridge 1 by displaying warning on a displaying portion provided on an operating panel 200, so that the state of the cartridge 1 is notified to the user.
For example, in the case where the unmounting of the cartridge 1 is detected, a message to the effect that there is no cartridge and that the mounting of the cartridge 1 is urged is displayed. Further, in the case where the second incompletely mounted state of the cartridge 1 is detected, a message to the effect that the cartridge 1 is stopped in an intermediate position and that pushing-in of the cartridge 1 in the horizontal direction is urged is displayed. Further, in the case where the first incompletely mounted state of the cartridge 1 is detected, a message to the effect that the cartridge 1 is not completely mounted and that strong pushing-in of the cartridge is urged is displayed.
In this way, the mounted state of the cartridge is displayed on the operating panel 200, whereby it is possible to avoid a status in which the user does not aware of the incompletely mounted state of the cartridge 1 and discriminates that the image forming apparatus 100 causes malfunction.
Incidentally, without displaying the warning on the operating panel 200 by using the message, a light-emitting diode for the warning may also be turned on.
Further, a signal may also be sent to an external computer to display a message, on the basis of the signal, on a monitor of the computer.
Thus, in this embodiment, even in the constitution in which the cartridge guides 103a and 103b are bent, the mounted state of the cartridge 1 and the position of the cartridge 1 in the apparatus main assembly 100A are detected stepwisely, and then it is possible to give the warning to the user. For that reason, it becomes possible to improve usability during the demounting and mounting of the cartridge 1.
Further, in this embodiment, when the cartridge 1 is inserted into the apparatus main assembly 1, even in the case where the cartridge 1 is stopped in a position between the electrical contacts for detecting the mounted state of the cartridge 1, a state in which three or more electrical contacts are always connected is created. For that reason, the presence state of the cartridge 1 in the apparatus main assembly 1 can be detected with reliability, so that it becomes possible to give clear warning to the user.
Further, in this embodiment, the grounding contact originally provided on the cartridge 1 is used as the electrical contact performing not only the function as the grounding contact for the photosensitive drum 2 but also the function of detecting the mounted state of the cartridge 1, and therefore it becomes possible to reduce the number of parts (components) as the electrical contacts only used for detecting the mounted state of the cartridge 1.
Another constitution example of this embodiment will be described. The electrical contacts used in this embodiment perform not only the function of detecting the mounted state of the cartridge but also the function of grounding the photosensitive drum by being connected with the photosensitive drum. However, as another example, the mounted state of the cartridge may also be detected by using, a developing contact, to be connected with the developing means, originally provided on the cartridge or by using a charging contact, to be connected with the charging means, originally provided on the cartridge.
The present invention is applicable to the image forming apparatus including the cartridge detachably mountable to the image forming apparatus.
According to the present invention, it becomes possible to detect the incompletely mounted state of the cartridge. For this reason, when the cartridge is detected as being in the incompletely mounted state, the user can receive clear instruction of an operating method and the cartridge can be moved to the incompletely mounted state without troubling the user, so that it becomes possible to improve usability.
While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purpose of the improvements or the scope of the following claims.
This application claims priority from Japanese Patent Application No. 262016/2012 filed Nov. 30, 2012, which is hereby incorporated by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-262016 | Nov 2012 | JP | national |
