In a frame transfer method and device by which an address space of a shared buffer can be effectively utilized without a reduction of the space even if an abnormal operation occurs in a management of the shared buffer, after frame data is written in the shared buffer during one monitor cycle when the frame data is to be read without fail from the shared buffer, an address space where the frame data has not been read from the shared buffer is detected during a next monitor cycle, and an address space where not a read but a write of the frame data has been performed at least during the monitor cycle is detected. In the next monitor cycle, the address space is released as a free address of the shared buffer.

1. Field of the Invention
The present invention relates to a frame transfer method and device, and in particular to a frame transfer method and device in an L2 switch using a shared buffer.
2. Description of the Related Art
Recently, devices have been micromachined, and an operation speed within a device and an interface speed between devices have been enhanced, so that a malfunction within the device, a noise of the interface between the devices, and the like have become considerable. Therefore, an abnormal operation may sometimes occur in an L2 switch or the like upon managing a shared buffer.
While such a problem has been approached by correction of data with an error correction code (ECC) or the like, the correction can be performed only to data with a single bit error or the like, but could not be performed to data with plural bit errors.
Therefore, when a parity error, an ECC error (uncorrectable error upon detecting plural bit errors), and the like are detected in a circuit managing the shared buffer, the prior art has prevented a malfunction by invalidating an area of the shared buffer. The prior art will now be described referring to the attached figures.
FIG. 7 schematically shows an example of the L2 switch using the shared buffer which has been conventionally known. As for L2 frame data (hereinafter, occasionally referred to as simply frame) inputted from each of ports P0-P3 of line interface unit (LIU) cards C#0-C#3, L2 frame terminating/generating portions TG#0-TG#3 respectively retrieve forwarding database (FDB) by using a destination address (DA) within the frame to acquire card information and port information of a frame transfer destination from the database FDB, and transfer the frame to a switch card SWC side. Upon the transferring, the card information and the port information are added to the frame.
When the destination address within the frame is not registered in the database FDB, the L2 frame terminating/generating portions TG#0-TG#3 add the card information and the port information to the frame to be transferred (flooded) to all of the LIU cards C#0-C#3, since the card information and the port information are not added to the L2 frame inputted from the switch card SWC. Namely, in the interface between the LIU cards C#0-C#3 and the switch card SWC, the card information and the port information are added for the purpose of transferring within the device.
The switch card SWC multiplexes the frames (including card information and port information) received through the ports P0-P3 from each of the LIU cards C#0-C#3 to be once stored in the shared buffer SB. Also, the address of the shared buffer SB upon storing the frame in the shared buffer SB is stored in a queue which will be described later, provided and managed per LIU card as a destination and per priority degree (hereinafter, referred to simply as priority) within the LIU card. Upon reading from the shared buffer SB, a switch portion SP performs a priority control per LIU card to acquire the address from the queue. The data (frame) is read from the shared buffer SB by using the acquired address to be transferred to the object LIU card.
The LIU cards C#0-C#3 specify a transfer destination port (any one or more ports of P0-P3 of LIU card) based on the L2 frame (including card information and port information) having received from the switch card SWC, and transfers the frame to the associated port. At this time, the information added to the frame in the L2 switch SW is deleted.
The specific arrangement and operation of the prior art switch card SWC in the L2 switch SW will now be described referring to FIGS. 8-11.
FIG. 8 shows a prior art example of the switch portion SP composing the switch card SWC together with the shared buffer SB. Firstly, upon writing a frame to the shared buffer SB, a frame inputted from each of the ports P0-P3 of the switch portion SP shown in FIG. 7 is multiplexed by a frame multiplexer 1 and transferred to a WAF read controller 2, a parity generator 3, a destination information/priority control information extractor 4, and the shared buffer SB.
The destination information/priority control information extractor 4 extracts destination information and priority control information added to the frame in the L2 frame terminating/generating portions TG#0-TG#3 in the LIU cards C#0-C#3, and transfers the extracted information to a write controller 6. Concurrently, the WAF read controller 2 acquires a free area (address) of the shared buffer SB from a Fifo (WAF: Write Address Fifo) 5 by designating a circular (iteration) address. Also, the WAF read controller 2 transfers the acquired free address to the shared buffer SB and the write controller 6 as a "write address". The parity generator 3 outputs a result (parity bit) after performing a parity calculation for the detection of failure to the frame inputted and outputs the frame, so that the shared buffer SB stores the parity result and the frame in the free area (write address) acquired from the write address Fifo 5 through the WAF read controller 2.
At this time, the write controller 6 sequentially selects the LIU card as a destination and a concerned queue among read queues 8_1-8_4 (hereinafter, occasionally represented by a reference numeral 8) provided per priority of the LIU card, based on the destination information and the priority control information transferred from the destination information/priority control information extractor 4, and transfers the write address acquired from the write address Fifo 5 to the selected queue. Also, a write flag WFLG for the selected queue is transferred to the read controller 10.
It is to be noted that four units of read queues 8 are shown in the example of FIG. 8, which indicates that e.g. the read queue 8-4 of destination α—high priority and the read queue 8-2 of destination α—low priority correspond to the LIU card C#1, and the read queue 8-3 of destination β—high priority and the read queue 8-1 of destination β—low priority correspond to the LIU card C#2. Accordingly, in the presence of four units of LIU cards C#0-C#3 as shown in the example of FIG. 7, 8 units of read queues are required, where only four units of the read queues are shown for convenience sake.
The parity generator among parity generators 7_1-7_4 (hereinafter, occasionally represented by a reference numeral 7) corresponding to the selected queue 8 outputs a result (parity bit) after performing the parity calculation for the detection of failure to the write address transferred from the write controller 6 and the write address, and the concerned queue 8 stores the write address as a "read address". When receiving the write flag WFLG transferred from the write controller 6, the read controller 10 monitors a queue capacity (read address) per queue 8, and counts up a capacity counter (not shown) installed in the read controller 10.
Upon reading the frame from the shared buffer SB, the read controller 10 can determine whether or not the frame data to be outputted is accumulated within the shared buffer SB, as mentioned above, with the capacity counter indicating the capacity of the read address stored in each queue 8.
When the capacity counter for monitoring per queue 8 is not "0", the read controller 10 performs the priority control and a fairness control (e.g. round robin) of each queue 8, and reads the read address from the queue 8 selected as a result of the control. Parity checkers 9_1-9_4 (hereinafter, occasionally represented by a reference numeral 9) perform the parity calculation to the read address read to be compared with the parity bit assigned by the parity generator 7.
In the presence of error found as a result of the comparison, the read controller 10 receives an error signal, and discards the read address read from the queue 8, so that the transfer to the shared buffer SB is not performed. Namely, the frame corresponding to the concerned read address is not read from the shared buffer. In the absence of error, the read controller 10 transfers the read address read from the queue 8 to the shared buffer SB and a WAF write controller 11. Also, the read controller 10 transfers to a frame demultiplexer 14 the information of the selected queue as output port information. When the destination α corresponds to the LIU card C#1 as with the above-mentioned example, information P1 indicating the port P1 of the switch portion SP corresponding to the output to the LIU card C#1 is transferred to the frame demultiplexer 14 as output port information.
The shared buffer SB takes out the data (frame) based on the read address received from the read controller 10, and the parity checker 12 at the subsequent stage performs the parity calculation to the data to be compared with the parity bit assigned by the parity generator 3.
In the presence of error found as a result of the comparison, the read frame is discarded by a data discard determining portion 13. In the absence of error, the read frame is transferred to the frame demultiplexer 14. The frame demultiplexer 14 demultiplexes the frame received from the data discard determining portion 13 to be transferred to a port designated by the output port information received from the read controller 10.
Also, the WAF write controller 11 stores the read address received from the read controller 10 in the write address Fifo 5 as data. The then address of the write address Fifo 5 assumes a circular address managed by the WAF write controller 11. By this operation, the shared buffer address where the frame is read from the shared buffer SB is to be stored in the write address Fifo 5 as a free address. In the following description, this operation is occasionally described as "returning a free address or return of a free address".
The above-mentioned write/read operation will now be described referring to the attached figures as an operation up to transferring the frame data inputted from each of the ports P0-P3 in the switch card SWC shown in FIG. 8 to the ports P0-P3 which form the destination.
Firstly, in the frame write side operation (writing operation) in the shared buffer SB having areas of addresses "0-1023" shown in FIG. 9, destinations and priorities are stored in header information head1-head4 of input frame data A, B, C, and D. As shown in FIG. 8, it is supposed that destination β—low priority, destination α—low priority, destination β—high priority, and destination β—high priority are respectively added to the frame data. It is to be noted that FIG. 9 shows an example where frame data with the same destination and different priorities are inputted at different times.
The frame data inputted from the ports P0-P3 respectively corresponding to the LIU cards C#0-C#3 are multiplexed by the frame multiplexer 1.
Thereafter, the WAF read controller 2 requests the write address Fifo 5 to acquire an address for storing the frame data in the shared buffer SB per frame data (in this example, the write addresses "0, 1, 2, and 3" for the shared buffer SB are acquired as a result).
Specifically, when receiving the frame data A, the WAF read controller 2 transmits the address "0" to the write address Fifo 5 (WAF) 5 as e.g. an initial value. The write address Fifo 5 transmits a free address "0" of the shared buffer SB to the WAF read controller 2 as data (subsequent address for the shared buffer SB). Similarly, when receiving the frame data B, C, and D, the WAF read controller 2 transmits circular addresses "1", "2", and "3" respectively to the write address Fifo 5, which sequentially transmits data "1", "2", and "3" of the circular addresses to the WAF read controller 2.
Thus, the WAF read controller 2, every time the frame data is received, increments an address to be transmitted to the write address Fifo 5, thereby requesting an acquisition of the shared buffer storing address (at steps S1 and S2). The WAF read controller 2 sequentially acquires the free addresses (addresses "0, 1, 2, and 3" in this example) of the shared buffer SB from the write address Fifo 5 (at step S3).
The parity generator 3 adds parity bits for the detection of failure to the acquired free address spaces "0, 1, 2, and 3" (at step S5), and writes the frame data A-D respectively in the addresses "0, 1, 2, and 3" of the shared buffer SB (at step S4).
Also, the destination information/priority control information extractor 4 extracts the header information of the frame data (in this example, destination β—low priority, destination α—low priority, destination β—high priority, and destination α—high priority corresponding to the frame data A, B, C, D respectively). The write controller 6, based on the extracted header information, writes in any one of the read queues 8_1-8_4 which are the transferring destination, the write address acquired from the WAF read controller 2 as data of the read address with the parity bit for the detection of failure generated by the parity generators 7_1-7_4 added (at step S5). In this example, the addresses "0, 1, 2, and 3" are respectively written as read addresses in the queues 8_1-8_4 corresponding to the write addresses "0, 1, 2, and 3".
In the read side operation (reading operation) at normal time shown in FIG. 10, the read controller 10 performs read scheduling (arbitration) to the read queues 8_1-8_4 in which the write addresses are stored in FIG. 9 (at step S6), and acquires the read addresses from the read queues 8_1-8_4. Upon the acquiring, checking the parity bit for the detection of failure is performed by the parity checkers 9_1-9_4 (at step S7). The addresses (no error is detected in failure detection) acquired at this time are used as addresses for reading the frame data from the shared buffer SB. It is to be noted that since the scheduling is performed in order of destination α with high priority, destination β with high priority, destination α with low priority, and destination β with low priority in this example, the addresses (read addresses) of the shared buffer SB are sequentially read in order of read queues 8-4, 8-3, 8-2, and 8-1, and accordingly from the shared buffer SB, the frame data D, C, B, and A respectively corresponding to order of addresses "3, 2, 1, and 0" are read.
The read controller 10 returns the acquired addresses (no error is detected in the failure detection) to the write address Fifo 5 as free addresses after reading the frame from the shared buffer SB (at steps S8 and S9), thereby releasing an available area. In this example, the next address data "3, 2, 1, and 0" are stored in the addresses "0, 1, 2, and 3" of the write address Fifo 5 through the WAF write controller 11 in order of reading the frame data D, C, B, and A from the shared buffer SB.
Accordingly, when the addresses "0, 1, 2, and 3" of the write address Fifo 5 are designated from the WAF read controller 2, writing the frame is performed respectively to the free addresses "3, 2, 1, and 0" of the shared buffer SB. However, since the WAF read controller 2 designates the circular address up to "1023" for the write address Fifo 5, when the WAF address "3" is designated corresponding to the frame data D as mentioned above, the address "4" of the write address Fifo 5 is to be designated for the frame which arrives next.
In the reading operation example (abnormal time) shown in FIG. 11, as with FIG. 10, read scheduling (arbitration) is performed by the read controller 10 to the read queues 8_1-8_4 in which the write addresses are stored as shown in FIG. 9 (at step S6) to acquire the read address from the read queue 8. Upon the acquiring, checking the parity bit for the detection of failure is performed (at step S7). The example of FIG. 11 shows a case where an error Err occurs in the parity check for the detection of failure in a part (addresses "1 and 2") of the addresses acquired. As for the addresses without error, the operation is the same as that described in FIG. 10.
As to data (addresses of the shared buffer SB) where the error Err has occurred, it is considered that a bit error has occurred. Therefore, the data (addresses) read from the queue 8 are invalidated (at step S10), and the addresses are not used for reading the frame data from the shared buffer SB (at step S11).
At this time, the read controller 10 does not return the addresses (errors are detected upon the failure detection) acquired to the write address Fifo 5 as areas read from the shared buffer SB. Specifically, the read controller 10 does not notify the data (addresses) having the errors Err occurred to the WAF write controller 11. Accordingly, in this example, only the frame data D and A of the addresses "3 and 0", free from error, of the shared buffer SB are read, and concurrently only the addresses "3 and 0" of the shared buffer SB are sequentially written as data of the addresses "0 and 1" of the write address Fifo 5. However, the data of addresses "2 and 3" of the write address Fifo 5 remain the same as FIG. 9.
Thus, in the prior art example, when an abnormal operation has occurred in the management of the shared buffer, a shared buffer area portion corresponding thereto is invalidated (not read), so that a malfunction has been prevented.
It is to be noted that there has been proposed a memory monitoring method which is provided with a used map monitoring portion, an unused map monitoring portion, and a search monitoring portion in addition to a data storing memory, an address storing memory, a parity inserting portion of a free address storing memory, and a parity abnormality detector, and which detects an address composition, an address disappearance, and an abnormal chain occurrence per chain (see e.g. patent document 1).
Also, there has been proposed a device in which an address management circuit portion of a shared buffer has a CAM managing a free address of the shared buffer and a read address per output port No., and an address retrieving portion retrieving the free address and the read address from the CAM, a management method of the address has a step of accumulating the free address of the shared buffer and the read address in a single CAM, and a step of retrieving the free address or the read address of the shared buffer by an address pointer of the CAM, and the address of the shared buffer of an ATM cell is managed (see e.g. patent document 2).
[Patent document 1] Japanese patent application laid-open No. 11-102325
[Patent document 2] Japanese patent application laid-open No. 11-261569
The operation description of the prior art examples shown in FIGS. 8-11 mentions the examples of no bit error occurrence (FIG. 10) and the bit error occurrence (FIG. 11) in the addresses read from the read queues 8_1-8_4, in which the read controller 10 has read all of the addresses written in the read queue 8 after the schedule management, where there is a difference in the state of the write address Fifo 5 after reading all of the addresses between the case where an error has occurred and the case where no error has occurred.
When no error has occurred, the frame data is read from the shared buffer SB by using the data (address) read from the read queue 8, thereby returning the data (address of the shared buffer SB) to the write address Fifo 5 as a free address space within the shared buffer SB. In this example, the writing in the read queue 8 and the read from the read queue 8 are respectively performed four times, and the return of free address to the write address Fifo 5 is performed four times (writing is performed four times), so that the number of free address spaces of the shared buffer SB stored in the write address Fifo 5 assumes 1024.
On the other hand, when an error has occurred, there is a high possibility that the data (address) read upon error occurrence includes a bit error. Therefore, the read data is invalidated, and the return of free address to the write address Fifo 5 is not performed. For this reason, in this example, the writing in the read queue 8 and the reading from the read queue 8 are respectively performed four times, and the return to the write address Fifo 5 is performed two times (write is performed two times), so that the number of free address spaces stored in the write address Fifo 5 assumes 1022 (−2 compared with the case of no error occurrence). Namely, when the read address is not returned as a free address to the write address Fifo 5, the addresses "1 and 2" of the shared buffer SB remain unused.
This results from the fact that the free area management of the write address Fifo 5 is performed based on a memory capacity. Namely, in the state of FIG. 11, the free addresses "0 and 3" of the shared buffer SB are stored in the addresses "1 and 0" of the write address Fifo 5, and the invalid (unused) addresses "2 and 3" of the shared buffer SB are stored in the addresses "2 and 3". The then free address areas (free address areas of the shared buffer SB) of the write address Fifo 5 are "1024−2=1022". In this state, the next frame data is written in the shared buffer SB with the data "4" indicated in the address "4" of the write address Fifo 5 being made a write address. The writing in the shared buffer SB is performed up to the address "1023" by the circular address, and then is performed to the addresses "0 and 1".
At this time, the capacity of the write address Fifo 5 becomes full (free address area of the shared buffer SB is 0), so that the writing in the shared buffer SB is stopped by the WAF read controller 2 managing the write address Fifo 5. Thereafter, when any of frame data is read from the shared buffer SB, the address of the shared buffer SB from which the frame data is read is returned as a free address to the address "2" of the write address Fifo 5.
As a result, the frame data B and C remain left in the shared buffer SB without being read.
Thus, the address space of the shared buffer SB in which an error was once detected and which could not be returned to the write address Fifo 5 can not be returned in the subsequent operation. Therefore, physically existing 1024 address spaces are reduced to 1022 (−2) address spaces by the error, so that there has been a problem that the capacity of the shared buffer SB becomes smaller every time an error occurs.


A Ziegler-Natta type catalyst having an improved hydrogen response provides for narrowing of the MWD of resulting polyolefins polymerized using such catalyst, with such catalyst generally made by a) contacting a soluble magnesium dialkoxide compound of the general formula Mg(ORxe2x80x3)2 with a halogenating agent capable of exchanging one halogen for one alkoxide to form a reaction product A, where Rxe2x80x3 is a hydrocarbyl or substituted hydrocarbyl having from 1 to 20 carbon atoms; b) contacting reaction product A with a first halogenating/titanating agent to form reaction product B; and c) contacting reaction product B with a second halogenating/titanating agent to form a catalyst component; wherein in at least one of steps b) and c), the halogenating/titanating agent is a blend of Ti(OPr)4 and TiCl4. Catalyst components, catalysts, catalyst systems, polyolefin polymers, and methods of forming each are disclosed.

1. Field of the Invention
The present invention relates to catalysts, to methods of making catalysts, to methods of using catalysts, to methods of polymerizing, and to polymers made with such catalysts. In another aspect, the present invention relates to polyolefin catalysts, to methods of making such catalysts, to methods of using such catalysts, to polyolefin polymerization, and to polyolefins. In even another aspect, the present invention relates to Ziegler-Natta catalysts, to methods of making such catalysts, to methods of using such catalysts, to polyolefin polymerization, and to polyolefins.
2. Description of the Related Art
Having been around since the early 1950""s, Ziegler-type polyolefin catalysts, their general methods of making, and subsequent use, are well known in the polymerization art.
However, while much is known about Ziegler-type catalysts, there is a constant search for improvements in their polymer yield, catalyst life, catalyst activity, and in their ability to produce polyolefins having certain properties.
U.S. Pat. No. 4,255,544, issued Mar. 10, 1981 to Kimura et al., discloses a process for polymerization of ethylene utilizing a catalyst comprising (A) the reaction product of a magnesium compound and titanium halide, and (B) an organic aluminum compound, wherein Component A is prepared by reacting magnesium dialkoxide with a hologen-containing silicon compound and an alcohol to provide a solid material and then reacting the solid material with titanium halide in the presence of an alkoxy-containing silicon compound.
U.S. Pat. No. 4,914,069, issued Apr. 3, 1990 to Job et al., discloses the preparation of an olefin polymerization catalyst component having improved activity and selectivity, which are prepared by (a) halogenating a magnesium compound containing at least one aryloxy, alkyl or carbonate or alkloxy group with a first halide of tetravalent titanium and a first electron donor; (b) contacting the resulting product with a second halide of tetravalent titanium; and (c) washing a resulting treated halogenated product with an inert hydrocarbon liquid. In the process, a second electron donor is used in step (a) or (b), and that the product of step (b) is contacted in a step (b2) with a third halide of tetravalent titanium at a temperature of 40xc2x0 C. to 140xc2x0 C. and thereafter the treated product is washed in step (c).
U.S. Pat. No. 5,155,187, issued Oct. 13, 1992 to Shelly, discloses a polymerization method utilizing a catalyst which is the reaction product generally of a silicon-containing compound, a magnesiumdialkyl, an alcohol, a halide-containing metal compound, an aluminum alkoxide, and a second halide-containing metal compound.
U.S. Pat. No. 5,610,246, issued Mar. 11, 1997 to Buehler et al., discloses a process for polymerizing propylene using a silica-supported catalyst. The catalyst comprises the product obtained by contacting silica, in random order, with (1) at least one hydrocarbon soluble magnesium-containing compound; and (2) a first modifying compound selected from the group consisting of silicon halides, boron halides, aluminum halides and mixtures thereof followed by a second specified modifying compound.
U.S. Pat. No. 5,631,334, issued May 20, 1997 to Zandona, disclose a process for the manufacture of a catalytic solid for the (co)polymerization of at least one olefin, comprising the coprecipitate magnesium and of at least one transition metal.
However, in spite of these advancements in the prior art, none of these prior art references disclose or suggest that the nature of R in a mixture of TiCl4/Ti(OiR)4 will provide a catalyst having improved hydrogen response which can provide polyolefins having narrower molecular weight distribution (xe2x80x9cMWDxe2x80x9d).
Thus, there is a need in the art for a polyolefin catalyst.
There is another need in the art for a method of making a polyolefin catalyst.
There is even another need in the art for a method of polymerizing olefins.
There is still another need in the art for polyolefins of narrower MWD.
There is yet another need in the art for a catalyst having improved hydrogen response.
There is even still another need in the art for a method of making a polyolefin catalyst that provides polymers having a narrow molecular weight distribution wherein the method comprises using a mixture of TiCl4/Ti(OiPr)4.
There is even yet another need in the art for a method of making polyolefins of narrower MWD.
These and other needs in the art will become apparent to those of skill in the art upon review of this specification, including its claims.
It is one object of the present invention to provide for a polyolefin catalyst.
It is another object of the present invention to provide for a method of making a polyolefin catalyst.
It is even another object of the present invention to provide for a method of polymerizing olefins.
It is still another object of the present invention to provide for polyolefins of narrower MWD.
It is yet another object of the present invention to provide a catalyst having improved hydrogen response.
It is even still another object of the present invention to provide for a method of making a polyolefin catalyst that provides polymers having a narrow molecular weight distribution wherein the method comprises using a mixture of TiCl4/Ti(OiPr)4.
It is even yet another object of the present invention to provide a method of making polyolefins of narrower MWD.
One embodiment of the present invention provides a catalyst component produced by a process generally comprising: a) contacting a soluble magnesium dialkoxide compound of the general formula Mg(ORxe2x80x3)2 with a halogenating agent capable of exchanging one halogen for one alkoxide to form a reaction product A, where Rxe2x80x3 is a hydrocarbyl or substituted hydrocarbyl having from 1 to 20 carbon atoms; b) contacting reaction product A with a first halogenating/titanating agent to form reaction product B; and c) contacting reaction product B with a second halogenating/titanating agent to form a catalyst component. Preferably, the first halogenating/titanating is a blend of Ti(OPr)4/TiCl4. The soluble magnesium dialkoxide compound is a reaction product of a reaction comprising an alkyl magnesium compound of the general formula MgRRxe2x80x2, wherein R and Rxe2x80x2 are alkyl groups of 1-10 carbon atoms and may be the same or different, and an alcohol of the general formula Rxe2x80x3OH wherein the alcohol is linear or branched and wherein Rxe2x80x3 is an alkyl group of 4-20 carbon atoms.
Another embodiment of the present invention provides a catalyst. Generally, the catalyst is produced by a process comprising contacting a catalyst component of the invention together with an organoaluminum preactivating agent. The catalyst component is generally produced by a process comprising, i) contacting a magnesium dialkoxide compound of the general formula Mg(ORxe2x80x3)2 with a halogenating agent capable of exchanging one halogen for one alkoxide to form a reaction product A, where Rxe2x80x3 is a hydrocarbyl or substituted hydrocarbyl having from 1 to 20 carbon atoms; ii) contacting reaction product A with a first halogenating/titanating agent to form reaction product B; and iii) contacting reaction product B with a second halogenating/titanating agent. Preferably the first halogenating/titanating agent is a blend of Ti(OPr)4/TiCl4. The catalyst of the present invention has an improved hydrogen response and is useful in producing a polymer of a desired molecular weight distribution.
Even another embodiment of the present invention provides a polymer produced by a process comprising a) contacting one or more xcex1-olefin monomers together in the presence of a catalyst of the invention under polymerization conditions. Preferably the catalyst is used to polymerize polyethylene monomers to produce polyethylene polymers. The catalyst is generally produced by a process comprising: i) contacting a soluble magnesium dialkoxide compound of the general formula Mg(OR)2 with a halogenating agent capable of exchanging one halogen for one alkoxide to form a reaction product A, where R is a hydrocarbyl or substituted hydrocarbyl having from 1 to 20 carbon atoms; ii) contacting reaction product A with a first halogenating/titanating agent to form reaction product B; and iii) contacting reaction product B with a second halogenating/titanating agent to form a catalyst component. Preferably, the halogenating/titanating agent in at least one of steps b) and c) is Ti(OPr)4/TiCl4. The catalyst producing process may further comprise contacting the catalyst component with an organoaluminum agent.
Still another embodiment of the present invention provides a catalyst system comprising a catalyst of the invention and an inert support. Preferably the inert support is a magnesium compound.
Yet another embodiment of the present invention provides a process for forming a catalyst component. Generally the process comprises:a) contacting a soluble magnesium dialkoxide compound of the general formula Mg(ORxe2x80x3)2 with a halogenating agent capable of exchanging one halogen for one alkoxide to form a reaction product A, where Rxe2x80x3 is a hydrocarbyl or substituted hydrocarbyl having from 1 to 20 carbon atoms. The process further comprises: b) contacting reaction product A with a first halogenating/titanating agent to form reaction product B; and c) contacting reaction product B with a second halogenating/titanating agent to form a catalyst component, or reaction product, C. Preferably the halogenating/titanating agent in at least one of steps b) and c) is Ti(OPr)4/TiCl4.
Even still another embodiment of the present invention provides a process for forming a catalyst, the process comprising contacting a catalyst component of the invention together with an organoaluminum preactivating agent.
Even yet another embodiment of the present invention provides a process for xcex1-olefin polymerization. Generally the polymerization process comprises: a) contacting one or more xcex1-olefin monomers together in the presence of a catalyst of the invention, under polymerization conditions; and b) extracting polyolefin polymer. The polymerization process is useful in producing polymers, preferably polyethylene polymer, having a molecular weight distribution of less than about 7.0.
These and other objects in the art will become apparent to those of skill in the art upon review of this specification, including its claims.
The method of the present invention for making a catalyst component generally includes the steps of forming a metal dialkoxide from a metal dialkyl and an alcohol, halogenating the metal dialkoxide, halogenating/titanating in one or more steps to form the catalyst with at least one of the steps utilizing mixture of TiCl4/Ti(OiPr)4, and then treating the catalyst with a preactivation agent such as an organoaluminum to form a preactivated catalyst.
A proposed mechanism for the method of the present invention is generally as follows:
MRRxe2x80x2+2Rxe2x80x3OHxe2x86x92M(ORxe2x80x3)2;xe2x80x83xe2x80x831.
M(ORxe2x80x3)2+ClARxe2x80x2xe2x80x3xxe2x86x92xe2x80x9cAxe2x80x9d;xe2x80x83xe2x80x832.
xe2x80x9cAxe2x80x9d+TiCl4/Ti(OPr)4xe2x86x92xe2x80x9cBxe2x80x9d;xe2x80x83xe2x80x833.
xe2x80x9cBxe2x80x9d+TiCl4xe2x86x92xe2x80x9cCxe2x80x9d; andxe2x80x83xe2x80x834.
xe2x80x9cCxe2x80x9d+TEAlxe2x86x92catalyst.xe2x80x83xe2x80x835.
In the above formulas, M may be any suitable metal, preferably a Group IIA metal, most preferably Mg. In the above formulas, R, Rxe2x80x2, Rxe2x80x3 and Rxe2x80x2xe2x80x3 are each independently hydrocarbyl or substituted hydrocarbyl moieties, with R and Rxe2x80x2 having from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms, more preferably from 2 to 6 carbon atoms, and even more preferably, from 2 to 4 carbon atoms. Rxe2x80x3 generally comprises from 3 to 20 carbon atoms, Rxe2x80x2xe2x80x3 generally comprises from 2-6 carbon atoms. Any combination of two or more of R, Rxe2x80x2, Rxe2x80x3 and Rxe2x80x2xe2x80x3 may be the same, or the R groups may be different from one another.
In the above formula ClARxe2x80x2xe2x80x3x, A is a nonreducing oxyphilic compound which is capable of exchanging one chloride for an alkoxide, Rxe2x80x2xe2x80x3 is a hydrocarbyl or substituted hydrocarbyl, and x is the valence of A minus 1. Examples of A include titanium, silicon, aluminum, carbon, tin and germanium, most preferred of which is titanium and silicon wherein x is 3. Examples of Rxe2x80x2xe2x80x3 include methyl, ethyl, propyl, isopropyl and the like having 2-6 carbon atoms. Rxe2x80x2xe2x80x3 is generally propyl.
While the exact composition of product xe2x80x9cAxe2x80x9d is unknown, it is believed that it contains a partially chlorinated metal compound, one example of which may be ClMg(ORxe2x80x3). The first chlorination/titanation produces product xe2x80x9cBxe2x80x9d which is probably a complex of chlorinated and partially chlorinated metal and titanium compounds and for example, may possibly be represented by (MCl2)yxe2x80x2. (TiClx(OPr)4xe2x88x92x)zxe2x80x2. The second chlorination/titanation produces a catalyst component xe2x80x9cCxe2x80x9d which is also probably a complex of chlorinated and partially chlorinated metal and titanium compounds but different from xe2x80x9cBxe2x80x9d and may possibly be represented by (MCl2)y. (TiClxxe2x80x2(OPr)4xe2x88x92xxe2x80x2)zxe2x80x2. It is expected that the level of chlorination of xe2x80x9cCxe2x80x9d would be greater than that of xe2x80x9cBxe2x80x9d. This greater level of chlorination would produce a different complex of different compounds. While this description of the reaction products offers the most probable explanation of the chemistry at this time, the invention as described in the claims is not limited by this theoretical mechanism.
Metal dialkyls and resultant metal alkoxides suitable for use in the present invention include any that which when utilized in the present invention will yield a suitable polyolefin catalyst. Preferred metal dialkoxides and dialkyls include Group IIA metal dialkoxides and dialkyls. More preferably the metal dialkoxide or dialkyl is a magnesium dialkoxide or dialkyl.
In the practice of the present invention, the magnesium dialkyl (MgRRxe2x80x2) may be any magnesium dialkyl where R and Rxe2x80x2 are as described above. R and Rxe2x80x2 may be the same or different. Non-limiting examples of suitable magnesium dialkyls include diethyl magnesium, dipropyl magnesium, dibutyl magnesium, butylethylmagnesium, etc. Butylethylmagnesium (BEM) is the preferred magnesium dialkyl.
In the practice of the present invention, the metal dialkoxide is preferably a magnesium compound of the general formula Mg(ORxe2x80x3)2 where Rxe2x80x3 is a hydrocarbyl or substituted hydrocarbyl of 1 to 20 carbon atoms.
The metal dialkoxide is most preferably soluble and most preferably non-reducing. A non-reducing compound has the advantage of forming MgCl2 instead of insoluble Ti+3 species formed by reduction of compounds such as MgRRxe2x80x2 which tend to form catalysts having a broad particle size distribution. In addition, Mg(ORxe2x80x3)2 is less reactive than MgRRxe2x80x2 and the chlorination with a mild chlorinating agent, followed by a simultaneous chlorination/titanation with a mild reagent and a second chlorination/titanation with a stronger reagent are gradual and successively stronger reactions which may result in more uniform product, i.e., better catalyst particle size control and distribution.
Non-limiting examples of preferred species of metal dialkoxides which are useful include magnesium butoxide, magnesium pentoxide, magnesium hexoxodie, magnesium di(2-ethylhexoxide), and any alkoxide suitable for making the system soluble. The most preferred metal alkoxide species is magnesium di(2-ethylhexoxide).
As a non-limiting example, a magnesium dialkoxide, such as magnesium di(2-ethylhexoxide), may be produced by reacting an alkyl magnesium compound (MgRRxe2x80x2), such as butyl ethyl magnesium (BEM), with an alcohol (ROH), such as 2-ethylhexanol.
MgRRxe2x80x2+2Rxe2x80x3OHxe2x86x92Mg(ORxe2x80x3)2+RH+Rxe2x80x2H
In the case of BEM, RH and Rxe2x80x2H are butane and ethane, respectively. The reaction takes place at room temperature and the reactants form a solution.
In the practice of the present invention, any alcohol yielding the desired metal dialkoxide may be utilized. As a non-limiting example, the alcohol may be any alcohol of the general formula Rxe2x80x3OH where Rxe2x80x3 is an alkyl group of 2-20 carbon atoms. The alcohol may be linear of branched. Non-limiting examples of the alcohol include ethanol, propanol, isopropanol, butanol, isbutanol, 2-ethyl-1-hexanol, etc. Generally, the alocohol utilized will have at least 3, preferably at least 4, more preferably at least 5, and most preferably at least 6 carbon atoms. While it is believed that almost any alcohol may be utilized, it is preferred that a higher order branched alcohol be utilized. The preferred alcohol is 2-ethylhexanol.
The amount of alcohol added to the slurry is generally in the range of about 0.5 equivalents to about 4 equivalents (equivalents are relative to the magnesium or metal compound throughout), preferably in the range of about 1 to about 3 equivalents.
Alkyl metal compounds are highly associative due to electron-deficient bonding which results in a high molecular weight species which is very viscous in solution. This high viscosity may be reduced by the addition of an aluminum alkyl, such as triethylaluminum, which disrupts the association between the individual alkyl metal molecules. The preferred ratio of alkyl aluminum to metal is 0.001:1 to 1:1, more preferably 0.01 to 0.1:1 and most preferably 0.03:1 to 0.05:1. In addition, an electron donor such as an ether, e.g. diisoamyl ether (DIAE) may be used to further reduce the viscosity of the alkyl metal. The preferred ratio of electron donor to metal is 0:1 to 10:1 and more preferably is 0.1:1 to 1:1.
Agents useful in the halogenating step for halogenating the metal alkoxide include any halogenating agent which when utilized in the present invention will yield a suitable polyolefin catalyst. Preferably the halogenating step is a chlorinating step and the preferred halogenating agent is a chloride.
Preferably, the chloride halogenating agent (xe2x80x9cchlorinating agentxe2x80x9d) is a monochloride compound which only partially chlorinates the magnesium alkoxide. The preferred chlorinating agent is of the general formula ClARxe2x80x2xe2x80x3x or ClAORxe2x80x2xe2x80x3x, where A is a nonreducing oxyphilic compound which is capable of exchanging one chloride for an alkoxide, Rxe2x80x2xe2x80x3 is alkyl and x is the valence of A minus 1. Examples of A are titanium, silicon, aluminum, carbon, tin and germanium, most preferred of which is titanium and silicon wherein x is 3. Examples of Rxe2x80x2xe2x80x3 are methyl, ethyl, propyl, isopropyl and the like having 2-6 carbon atoms. Examples of a chlorinating agent effective in the present invention are ClTi(OiPr)3 and ClSi(Me)3.
Halogenating the metal alkoxide compound is generally conducted in a hydrocarbon solvent under an inert atmosphere. Non-limiting examples of suitable solvents include toluene, heptane, hexane, octane and the like. The preferred solvent is hexane.
The halogenating step is generally carried out at a temperature in the range of about 0xc2x0 C. to about 100xc2x0 C. and for a reaction time in the range of about 0.5 to about 24 hours. Preferably, the halogenating step is carried out at a temperature in the range of about 20xc2x0 C. to about 90xc2x0 C. and for a reaction time in the range of about 1 hour to about 4 hours.
Once the halogenating step is carried out and the metal alkoxide halogenated, the soluble product xe2x80x9cAxe2x80x9d is subjected to one or more halogenation/titanation treatments, at least one of which must utilize a mixture of TiCl4/Ti(OiPr)3. Preferably, the first halogenation/titanation step utilizes a mixture of TiCl4/Ti(OiPr)3.
In general, the halogenating/titanating agent is a tetrasubstituted titanium compound with all four substituents being the same and the substituents being a halide or an alkoxide or phenoxide with 2 to 10 carbon atoms, such as TiCl4 or Ti(ORxe2x80x3xe2x80x3)x. The halogenating/titanation agent is preferably a chlorination/titanation agent.
The preferred chlorinating/titanating agent may be a single compound or a combination of compounds. The method of the present invention provides an active catalyst after the first chlorination/titanation step; however, chlorination/titanation is preferably performed twice, using a different compound or combination of compounds at each addition, and uses a stronger chlorination/titanation agent with each successive chlorination/titanation treatment.
The first chlorination/titanation agent is preferably a mild titanation agent, preferably a blend of a titanium halide and a organic titanate. It is believed that the blend of titanium halide and organic titanate react to form a titanium alkoxyhalide, Ti(OR)aXb, where OR and X are an alkoxide and halide, respectively, a+b is the valence of titanium which is typically 4 and both a and b may be fractional, e.g. a=2.5 and b=1.5.
More preferably, the first chlorinating/titanating agent is a blend of TiCl4 and Ti(OiPr)3 or a blend of TiCl4 and Ti(OiPr)4. At least one of the chlorination/titanation steps must utilize a blend of TiCl4 and Ti(OiPr)4 and it is preferred that the first chlorinating/titanating agent is a blend of TiCl4 and Ti(OiPr)4.
For either TiCl4/Ti(OBu)4 or TiCl4/Ti(OiPr)4, the ratio of TiCl4 to either Ti(OBu)4 or Ti(OiPr)4 (whichever is utilized) is in a range from 0.5:1 to 6:1, more preferably from 1:1 to 4:1, and most preferably from 2:1 to 3:1. (OC12H5)Cl3.
The first halogenation/titanation step is generally carried out in a hydrocarbon solvent. Nonlimiting examples of suitable hydrocarbon solvents include heptane, hexane, toluene, octane and the like. The product xe2x80x9cAxe2x80x9d is soluble in the hydrocarbon solvent.
A solid product xe2x80x9cBxe2x80x9d is precipitated at room temperature following the addition of the first halogenation/titanation agent to the soluble product xe2x80x9cAxe2x80x9d.
The amount of halogenation/titanation agent utilized must be sufficient to precipitate a solid product from the solution. In general, the amount of halogenation/titanation agent utilized, based on the ratio of titanium to metal will generally be in the range of about 0.5 to about 5, preferably in the range of about 1 to about 4, and most preferably in the range about 1.5 to about 2.5.
The solid product xe2x80x9cBxe2x80x9d precipitated in the first titanation step is then recovered by any suitable recovery technique, and washed with a hydrocarbon solvent.
Compounds suitable for use as the second halogenation/titanation agent include those suitable for use as the first halogenation/titanation agent, except that preferably, the second agent is a stronger agent. The second halogenation/titanation agent is stronger, and is preferably a titanium halide, more preferably titanium tetrachloride [TiCl4].
The second halogenation/titanation step is generally carried out by slurrying the solid product xe2x80x9cBxe2x80x9d in a hydrocarbon solvent to produce reaction product, or catalyst component, xe2x80x9cCxe2x80x9d. Hydrocarbon solvents listed as suitable for the first halogenation/titanation step may be utilized. In general, the amount of titanium tetrachloride utilized will generally be in the range of about 0.1 to about 5 equivalents, preferably in the range of about 0.15 to about 4 equivalents, most preferably in the range of about 0.175 to about 2.5.
The catalyst component xe2x80x9cCxe2x80x9d may be combined with an organometallic cocatalyst component (a xe2x80x9cpreactivating agentxe2x80x9d) to form a preactivated catalyst suitable for the polymerization of olefins. Typically, the cocatalysts which are used together with the transition metal containing catalyst component xe2x80x9cCxe2x80x9d are organometallic compounds of Group Ia, IIa, and IIIa metals such as aluminum alkyls, aluminum alkyl hydrides, lithium aluminum alkyls, zinc alkyls, magnesium alkyls and the like.
The preactivating agent is preferably an organoaluminum compound, more preferably an aluminum alkyl of the formula AlR{circumflex over ( )}3 where R{circumflex over ( )} is an alkyl having 1-8 carbon atoms or a halide. Preferred organoaluminum preactivating agents include trialkyl aluminums, such as, for example, trimethyl aluminum (TMA), triethyl aluminum (TEAl) and triisobutyl aluminum (TiBAl). The preferred preactivating agent is TEAl. The ratio of Al to titanium is in the range from 0.01:1 to 2:1 and preferably is 0.25:1 to 1.2:1. Subsequently, the catalyst is recovered and washed with a hydrocarbon solvent.
Optionally, an electron donor may be added with the halogenation agent, the first mild halogenation/titanation agent, or the second stronger halogenation/titanation agent. Most preferably, an electron donor is utilized in the second halogenation/titanation step. Electron donors for use in the preparation of polyolefin catalysts are well known, and any suitable electron donor may be utilized in the present invention which will provide a suitable catalyst.
Electron donors, also known as Lewis bases, are organic compounds of oxygen, nitrogen, phosphorous, or sulfur which can donate an electron pair to the catalyst.
The electron donor may be a monofunctional or polyfunctional compound, advantangeously selected from among the aliphatic or aromatic carboxylic acids and their alkyl esters, the aliphatic or cyclic ethers, ketones, vinyl esters, acryl derivatives, particularly alkyl acrylates or methacrylates and silanes. A preferred example of a suitable electron donor is di-n-butyl phthalate. A more preferred example of a suitable electron donor is an alkylsilylalkoxide of the general formula RSi(ORxe2x80x2)3, e.g., methylsilyltriethoxide [MeSi(OEt3)], where R and Rxe2x80x2 are alkyls with 1-5 carbon atoms and may be the same or different.
The support of the catalyst system of the present invention should be an inert solid which is chemically unreactive with any of the components of the conventional Ziegler-Natta catalyst. The support is preferably a magnesium compound. Examples of the magnesium compounds which are to be used to provide a support for the catalyst component are magnesium halides, dialkoxymagnesiums, alkoxymagnesium halides and carboxylates of magnesium. The preferred magnesium compound is a magnesium chloride (MgCl2).
Optionally, the Ziegler-Natta catalyst may be pre-polymerized. Generally, a prepolymerization process is effected by contacting a small amount of monomer with the catalyst after the catalyst has been contacted with the co-catalyst. A pre-polymerization process is described in U.S. Pat. Nos. 5,106,804; 5,153,158; and 5,594,071, hereby incorporated by reference.
The catalyst may be used in any known process for the homopolymerization or copolymerization of any type of xcex1-olefins. For example, the present catalyst may be useful for catalyzing ethylene, propylene, butylene, pentene, hexene, 4-methylpentene and other xcex1-alkenes having at least 2 carbon atoms, and also for mixtures thereof. Preferably, the catalysts of the present invention are utilized for the polymerization of ethylene to produce polyethylene.
The activity of the catalyst of the present invention at least partially depend upon the polymerization process and conditions. Generally, the catalyst has an activity of at least 6,000 gPE/g catalyst, but the activity may also be greater than 100,000 gPE/g catalyst.
Additionally, the resulting catalyst of the present invention provides a polymer with excellent fluff morphology. Thus, the catalyst of the present invention provides for large polymer particles with a uniform distribution of sizes, wherein small, extremely fine particles (less than about 125 microns) are only present in low concentrations. The catalysts of the present invention, which include large, readily transferred powders with high powder bulk densities, are amenable to polymerization production processes.
The polymerization process may be bulk, slurry or gas phase. It is preferred to use a catalyst synthesized above in a slurry phase polymerization. The polymerization conditions (e.g., temperature and pressure) are dependent upon the type of equipment utilized, as well as the type of polymerization process performed, and are known in the art. Generally the temperature may be in a range of about 50-200xc2x0 C. and the pressure in a range of about 10-800 psi.
The olefin monomer may be introduced into the polymerization reaction zone in a diluent which is a nonreactive heat transfer agent which is liquid at the reaction conditions. Examples of such a diluent are hexane and isobutane. For the copolymerization of ethylene with another alpha-olefin, such as, for example, butene or hexene, the second alpha-olefin may be present at 0.01-20 mole percent, preferably 0.02-10 mole percent.
For the polymerization process, it may be preferred to include an internal electron donor in the synthesis of the catalyst and an external electron donor or stereoselectivity control agent (SCA) to activate the catalyst at polymerization. An internal electron donor may be used in the formation reaction of the catalyst during the chlorination or chlorination/titanation steps. Compounds suitable as internal electron-donors for preparing conventional supported Ziegler-Natta catalyst components include ethers, diethers, ketones, lactones, electron donors compounds with N, P and/or S atoms and specific classes of esters. Particularly suitable are the esters of phthalic acid, such as diisobutyl, dioctyl, diphenyl and benzylbutylphthalate; esters of malonic acid, such as diisobutyl and diethylmalonate; alkyl and arylpivalates; alkyl, cycloalkyl and arylmaleates; alkyl and aryl carbonates such as diisobutyl, ethyl-phenyl and diphenylcarbonate; succinic acid esters, such as mono and diethyl succinate.
External donors which may be utilized in the preparation of a catalyst according to the present invention include organosilane compounds such as alkoxysilanes of general formula SiRm(ORxe2x80x2)4xe2x88x92m where R is selected from the group consisting of an alkyl group, a cycloalkyl group, an aryl group and a vinyl group; Rxe2x80x2 is an alkyl group; and m is 0-3, wherein R may be identical with Rxe2x80x2; when m is 0, 1 or 2, the Rxe2x80x2 groups may be identical or different; and when m is 2 or 3, the R groups may be identical or different.
Preferably, the external donor of the present invention is selected from a silane compound of the following formula:
wherein R1 and R4 are both an alkyl or cycloalkyl group containing a primary, secondary or tertiary carbon atom attached to the silicon, R1 and R4 being the same or different; R2 and R3 are alkyl or aryl groups. R1 may be methyl, isopropyl, cyclopentyl, cyclohexyl or t-butyl; R2 and R3 may be methyl, ethyl, propyl, or butyl groups and not necessarily the same; and R4 may also methyl, isopropyl, cyclopentyl, cyclohexyl or t-butyl. Specific external donors are cyclohexylmethydimethoxy silane (CMDS), diisopropyldimethoxysilane (DIDS) cyclohexylisopropyl dimethoxysilane (CIDS), dicyclopentyldimethoxysilane (CPDS) or di-t-butyl dimethoxysilane (DTDS).
Polyethylene produced using the above described catalyst will have an MWD less than about 7.0, preferably less than about 6.0, more preferably less than about 5.5, and even more preferably less than about 5.0.
The invention having been generally described, the following examples are given as particular embodiments of the invention and to demonstrate the practice and advantages thereof. It is understood that the examples are given by way of illustration and are not intended to limit the specification or the claims to follow in any manner.

Hydrogen response Ziegler-Natta catalyst for narrowing MWD of polyolefin, method of making, method of using, and polyolefins made therewith


A folding and glueing device (30) for folding and applying glue to the closure flaps (5) of blanks in continuously moving "wrap-around" sleeve packaging machines comprises a pair of coaxial and interconnected rotary members (14, 18), at least one driven rotary bar (26) borne in a rotary manner by and between the pair of rotary members (14, 18), transmission means (15, 28, 27) adapted to rotate the rotary bar (26) in phase relationship with the rotation of the pair of rotary members (14, 18), a closure blade disposed and secured along the rotary bar (26) and spray glueing means (22) positioned between the pair of rotary members (14, 18) in a central zone that does not interfere with the path described by the rotary bar (26) which is caused to move along a circular path by the rotary members (14, 18).

Field of the Invention
The present invention relates to a folding and glueing device for folding and applying glue to the closure flaps of blanks in continuously moving "wrap-around" sleeve packaging devices, as disclosed, for instance, in British Patent Specification 2 233 954 in the name of the applicants.
The invention relates more particularly to a folding and glueing device of the above-mentioned type that is particularly adapted to cardboard wrap-around packagings in which the closure flap is articulated on the free end of the rear panel and has to be disposed within the finished package.
In this particular technological sector, the wrap-around blanks used by these packaging machines substantially comprise a first set of panels, normally four, extending longitudinally and consecutively in order to form the rear wall, the base wall, the front wall and the upper wall of the package when it is wound in the form of a sleeve about the product, eight lateral flaps articulated on the opposite longitudinal sides of the four panels mentioned above and adapted to form the heads of the package and a closure flap articulated on the longitudinal free end of the rear panel and adapted to be glued underneath the longitudinal free end of the upper panel.
Continuous packaging machines of the wrap-around sleeve type comprise a production line that substantially carries out the following operations: the association of the individual products with respective individual blanks by disposing these products on the base panel of these blanks; the partial winding of the individual blanks in the form of a sleeve about the respective products by erecting the rear panel against the rear portion of the product, the front panel against the front portion of the product and the upper panel over the upper portion of the product in a partly raised manner; the folding back over the heads of this product of the four flaps articulated on the sides of the rear panel and on the sides of the front panel; the folding towards the interior of the package of the closure flap and the application of glue to the upper surface thereof; the lowering of the upper panel in order to cause this closure flap to adhere to the inner longitudinal end portion of the upper panel; the application of glue to the outer surfaces of the four flaps previously folded back over the heads of the product; and, lastly, the folding of the flaps articulated on the upper panel and on the base panel against the flaps previously folded against the heads in order to obtain the fastening of these flaps.
At present, operations to fold the closure flap towards the interior of the package and to apply the glue thereto are carried out by folding and glueing devices provided with an alternating and/or intermittent movement which do not enable faultless folding of the closure flap, do not enable the use of high operating speeds and do not enable the correct application of the glue since during the spraying of this glue the plane of the closure flap is not perpendicularly opposite to the direction of spray from the nozzles.

Folding and glueing device for folding and applying glue to the closure flaps of blanks in continuously moving "wrap around" sleeve packaging machines


A device (20) for an automotive vehicle (10) is provided to indicate the buckled and unbuckled status of a seatbelt (24). The device (20) has a self-powered wireless switch assembly (22) that is coupled to the seatbelt (24). It provides power to power a wireless transmitter (44) to transmit a wireless signal (45) corresponding to the buckled and unbuckled state of the seatbelt (24). The self-powered wireless switch assembly (22) harvests energy from the mechanical action of the seatbelt (24). The device (20) transmits a wireless signal (45) indicating the seatbelt (24) status. The receiver (18) located in the automotive vehicle (10) receives the wireless signal (45). The wireless signal (45) is processed by a safety information system (12) and then visually and audibly displayed by an indicator (16) to alert the driver of the seatbelt (24) status.

The present invention generally relates to seatbelt systems for automotive vehicles and, more particularly, to seatbelt usage indication systems for automotive vehicles.
The automotive industry has experienced significant growth with onboard safety information systems, also referred to as cabin communication systems. These systems help the vehicle operator better assess the status of the various vehicle conditions. Some of the vehicle conditions include inside temperature, door ajar, and seatbelt buckling. When a condition changes, the system alerts the operator with an audible, and or, a visual alarm transmitted from the onboard safety information systems. The onboard safety information system includes smaller systems that monitor specific conditions; such as identifying, among other things, the location of buckled and unbuckled seatbelts when the vehicle is in operation. The seatbelt indication system is one such system.
The seatbelt indication system can relay the information to the onboard safety information system or send the information directly on to the indication system to alert the operator. With the seatbelt indication system, the operator receives an alert identifying that seatbelts are, or are not, in use. The seatbelt indication system includes a sensor that gathers the seatbelt status from a sensor wired into the vehicle's cable harness and mounted on each seatbelt buckle assembly.
The cable harness is used to connect the seatbelt sensor to the seatbelt indication system. The cable harness provides power for the sensor. The cable harness also provides a continuous communication connection to send the seatbelt status to any other subsystem that might need the information.
For each seatbelt sensor connection, the associated cost to supply power and a communication link is proportional to the number of connections made. Furthermore, the routing of wires to transfer power or data is very difficult in a customer friendly way when the connection is to a foldable or removable seat. Also, each seatbelt sensor added increases the input ports needed to connect to the systems input circuitry in the seatbelt indication system.
A cable harness may prove to be unreliable where the seat is foldable or removable due to user error in the disengagement and engagement of a cable connection. The cable harness is more prone to wear or damage when routed to foldable and or removable seats. Also, the system may prove to be inoperable where the user might simply forget to reconnect a cable after disengaging it. Other means of making electrical contact connection with the sensor for a removable seat could be employed at or near the place where the seat connects to the floor, but these means would also be prone to contamination and abuse. It would be advantageous to provide seatbelt sensor that is not wired into a cable harness, but could still communicate seatbelt status to the seatbelt indication system.
In another configuration for removable seats, as disclosed in U.S. Pat. No. 6,362,734, the onboard safety information system gathers the seatbelt status from a non-contact data link. The non-contact data link consists of a closely adjacent non-powered transceiver/transponder connection. This non-powered wireless connection is comprised of a transponder and transceiver. The transponder is coupled to the removable seat and is electrically connected with the seatbelt sensors. The transceiver is attached to the automotive vehicle and electrically connected with the seatbelt indication system or other similar systems, as mentioned above. The transceiver is located in the vehicle so that it will be closely adjacent to the transponder when the removable seat is placed back into the automotive vehicle after removal. The closely coupled position between the transceiver and transducer must be maintained in order for the transducer to receive the radiated energy from the transceiver sufficient to power it. If the transceiver and transponder are not properly located adjacent to each other, then the non-powered transponder will not receive enough radiated energy necessary to send a signal back to the transceiver.
Also, each non-contact data link requires a transceiver/transponder set. And each transceiver requires a connection to the seatbelt indication system that increases the cost and system complexity if a transceiver/transponder is used at every seating location in the automotive vehicle.
In view of the above, it would be advantageous to have a self-powered wireless switch assembly that transmits the unbuckled or buckled status of the seatbelt not being dependent upon a closely coupled wireless or hardwired connection. It would also be beneficial to have the identity of the self-powered wireless switch assembly identifiable at the source. The final advantage would be to have a system that requires only one receiver to receive the status of one or more self-powered wireless switch assemblies onboard an automotive vehicle.

Wireless seatbelt buckle switch harvesting energy and method therefor


An image processing sensor system functions as a standalone unit to capture images and process the resulting signals to detect objects or events of interest. The processing significantly improves selectivity and specificity of detection objects and events in a series of motions that may precede a patient who is at elevated risk of falling.

1. Field
The present disclosure pertains to methods and apparatus for processing images. More specifically, it employs systems and software to detect and identify specific human movements or postures, which are predictors of certain activities so that interested third parties may be notified, with a preferred embodiment operating as an observation/supervision device for patients in bed who have been identified as fall risk.
2. Statement of the Problem
A variety of commercially available sensor types may be used to monitor space and report on a wide range of parameters. The sensor types are associated with different technologies, each exhibiting its own set of advantages and disadvantages. There is a need to improve sensor performance, accuracy and the ability to assess parameters of interest within the monitored space.
The most widely used sensors are of a low cost design. These sensors are crude by modern information processing standards. The currently available sensors for motion, for example, are unable to provide any information regarding detected motion and therefore, trigger for any motion that occurs in the field of view, regardless of the source of motion. By way of illustration, when a sensor is installed to turn on lights in a driveway when a car pulls up, the motion detector problematically activates for passing dogs that walk by, trees moving in a breeze, and even for an optical heat gradient created by the rising sun. These latter occurrences are all categorized as false-positive events, since the objective is selective activation for an approaching car. These sensors correctly detect an intrusion so the system is operating with sufficient selectivity to detect an intrusion event; however, specificity is poor because the system cannot discriminate to ascertain the nature of the intrusion. One solution to avoid such problems is to limit the monitored space. For example, one manufacturer of a driveway monitor device states in the product specification that the "signal should be installed at a height of 4 feet to avoid feedback interference errors from the ground." This solution is less than satisfactory because it fails to accurately detect intrusion events occurring below a certain height because of ground interference.
Current low cost sensors have poor specificity because there is insufficient resolution to discriminate between different objects or events that fall within their field of view. This inability to detect and respond appropriately for a detected object or event is directly responsible for increased cost of support and may even endangers lives. In one example, a small rodent running across the floor can set off a motion detector, triggering an intruder alarm and causing a police response. Some manufacturers offer 'pet immune' detectors, so an alarm is claimed to not trigger by the homeowner's dog for home security systems. These systems do not recognize pets. They are quantifying the heat mass of the object using an infrared sensor and, based on some threshold value, signal an alarm accordingly. Obviously, if the dog runs around the house excitedly because it hears the garbage truck outside, the heat mass will elevate possibly triggering an alarm. Furthermore, there is no ability to discriminate between a dog and a small child.
Nor is it the case that higher-end systems solve these problems in a satisfactory manner. The prior art contains a variety of programming techniques related to the processing of digital video images. Considerable prior art surrounds the processing of video images in an effort to recognize objects or events in the monitored or recorded footage. Applications are primarily intended for surveillance or security purposes. These systems use video cameras to capture video footage in the field of view and transmit the video signal, either through a cable interconnect or wirelessly, to a remote processing station where the video footage is processed. These video systems require high data bandwidth and considerable infrastructure to support the transmission of video signals to remote processing stations. These needs greatly increase the cost of deployment and operation. Also, the image analysis is performed post-event at a central processing station, which typically supports multiple video cameras. The system requirement for central processing greatly increases the required processing power of the central station, the complexity of its operation and the process is analyzing history, rather than real-time. The complexity of video systems is further increased to satisfy one of the primary purposes, which is preservation of records for future reference. Furthermore, video cameras are expensive and complex devices, which lower their reliability.
Digital imaging systems have become very inexpensive to produce. As a result, image creation is a standard feature on most modern handheld communication devices, e.g., cell phones and PDAs. Image creation technology has been commoditized to greatly reduce the cost to create a digital image. These commodity components provide a low cost, stand-alone, reliable image capture hardware platform.
Recently, systems and methods have been disclosed that have taken advantage of the commoditization of image creation technology and incorporated imaging capability into monitoring applications. U.S. Pat. No. 7,231,654, entitled "Remote Monitoring Method and Monitor Control Server" ("the '654 patent") describes method where an image capture device is added to a remote monitoring device that is connected to monitor control server. The '654 patent essentially adds an image capture capability to a conventional motion detector used for security monitoring, where an image is captured only when the motion detector triggers and the image is transmitted to the control server without any image processing being performed by the remote monitor. The control server then formats the image for transmission to a mobile terminal, such as a PDA or cell phone, where the image may be viewed by a user.
The '654 patent repeats the problems of the prior sensor art. The disclosure does not provide any imaging processing at the remote monitor and, in fact, does not provide any image processing throughout the entire system. The image capture capability is only used to capture an image and pass it through the system using various communication methods to enable the image to be reviewed remotely. The '654 patent does not provide any improvement to the sensor art and only offers improvement to the notification methods for existing security systems.
In another example of prior art that falls short of providing any improvement to the general sensor art is disclosed in U.S. Pat. No. 6,697,104 ("the '104 patent"), entitled "Video Based System and Method for Detecting and Counting Persons Traversing an Area Being Monitored." The '104 patent discloses a dedicated remote video device having a single function, namely, to count the number of people that enter or exit a monitored area. The data collected by the remote monitoring device must be uploaded to a remote processing station where additional processing activity is required to provide any useful value. Several prerequisites exist regarding the deployment environment that severely limits the functional value of the disclosure. The '104 patent provides some limited ability to 'configure' the remote monitoring device once it is installed at its deployment location to account for the environment of use however, the configuration capability is limited to the 'area of interest,' subdividing the field of view. Accordingly, the 'counting' function is limited to only a part of the captured video signal.
Using video signals, the remote monitoring device of the '104 patent processes frames of video but never actually recognizes the presence of a person. There is merely recognition of artifacts of "what might be a person." For example, if a dog were to pass through the field of view, the system may or may not count the dog as person. This happens because the '104 patent relies upon on a static background image. There is subtraction of this background to identify a patterned characteristic change in the background that is assumed to represent a person; however, this is not a process that recognizes the object itself. Only an artifact of the image is observed as a change in the background. Furthermore, the '104 patent registers person counts in some internal counters that must be uploaded to another computer system where the counts must be processed and formulated into a useable format for a subscription based customer model. The remote monitoring device does not produce output that contains any actionable information. The single, dedicated function of the remote monitoring device cannot be reprogrammed, and its inability to receive 'count' objects other than people is limiting.
U.S. Pat. No. 7,190,259 ("the '259 patent") discloses a lens arrangement to create a 360 degree view for a video imaging component. The system displays the captured image on a screen. The lens is deployed in the exterior rearview mirrors of an automobile. The image is displayed for driver viewing. The omni-directional vision sensor merely delivers output for presentation of the image and does not process the image.
U.S. Pat. No. 7,414,647 ("the '647 patent") describes another lens arrangement to create a 360 degree view for a video imaging component. Again the system displays the image on a remote terminal screen. The image capture and processing device has limited processing to format the image data into either panoramic or perspective views for display purposes. A mobile body detecting section is disclosed for detecting a moving body in the field of view. The primary application disclosed is for deployment in an ATM to capture images of ATM users. A 'communication section' telecommunicates with an external terminal device. The data can be transmitted either wirelessly or via cable interconnect but again, its limited strictly to image data. There is no discussion anywhere in the disclosure of the image capture and processing device receiving any information or of the communication section being used to receive data.
U.S. Pat. No. 7,200,246 ("the '246 patent") discloses an imaging system and method directed toward industrial equipment safety by monitoring an 'area of interest' and detecting an object entering the area. The image capture and processing device contains image processing algorithms for object detection, an output signal and the ability to connect a PC to the image capture and processing device for configuration. However, the disclosed capability all relates to an 'area of interest' in the manner of a motion detector and do not address the selective identification of 'objects of interest', nor are any image processing functions or algorithms transferred to image capture and processing device through the PC connection.
The 'area of interest' is monitored by the image capture and processing device employing a defined border area. The image processing relies on the use of a reference image, where sampled images are subtracted from the reference image and changes in pixel pigmentation are used to determine if an object has 'breached' the border of the monitored area of interest. While the disclosure includes discussion of establishing a 'threshold' for the number of pixels required to trigger an output signal, even referencing a "hand", there is no attempt by the '246 patent disclosure to recognize the object breaching the border.
Human falls are the leading cause of injury for persons over the age of 65 and can occur in any environment, including hospitals, long term care, retirement housing or single family dwellings. Falls are especially prevalent in health care environments where patients under care generally have reduced physical or mental capacity. The occurrence of falls in health care environment is so pronounced that the reduction of the number of injuries resulting from patient falls is one of the Joint Commission's patient safety goals. The growth in the number of older adults has led to more aggressive efforts to promote independent living and expansion in monitoring the well being of older individuals, for all possible living environments. Given the occurrence of falls, the need to monitor and report has become a critical element of society. While falls can occur during any activity, the great percentage of incidences occurs when an individual transitions from lying down or sitting.
Monitoring human activity is not limited to fall risk individuals. General monitoring of elderly who live alone is a prime activity monitoring application. Many other applications exist, for example, with prison and jail overcrowding, the image capture and processing system can be trained to look for particular movements or postures, which are characteristic of activities that may be harmful to prison personnel or inmates, specifically inmates who are placed on suicide watch. Other example applications include schools, which have become increasingly hazardous and the present instrumentality can be used to monitor children leaving designated areas or other individuals entering certain school areas and identifying suspicious articles being carried. Other applications will become apparent to those skilled in the art and this disclosure will focus on a generalized description of a bed monitor application.
There are a number of different patient bed monitoring systems and methods disclosed in the prior art. Most of the bed monitoring systems disclosed involves some contact with the patient. Patient contact requires the sensor component of the patient bed monitor system to be properly positioned or attached to the patient, which makes it subject to mis-alignment or removal by the patient that generally results in a false alarm. Another considerable drawback of system and methods described in prior art is that they are limited to reporting on the presence or absence of patient, as described in U.S. Pat. No. 6,917,293 to Beggs (Beggs '293). Reporting the absence of a patient from bed is too late as the patient is already out of bed unassisted with a 30% chance he or she has already fallen.
One disclosed bed monitoring system utilizes image analysis and purports to provide utility for fall prevention and detection. The system described in U.S. Pat. No. 5,541,934 to Fredriksson (the '934 patent), as with other devices, is primarily used for reporting that a fall has occurred. Further, the disclosed invention relies on an optical sensor given in a separate patent, where a central station is claimed for receiving images to be reviewed by an operator. Another drawback of the '934 patent is that it requires images to be saved for later analysis if some future event occurs. This specifically teaches away from a real-time image analysis system. Saving images and transmitting to a remote location raises privacy concerns for patient monitoring and makes the '934 patent unsuitable for use by health care facilities.
The '934 patent includes language whereby the invention purports to provide fall prevention by identifying a person leaving the bed to end up standing beside the bed. The need for the invention to have a person go from laying down to standing beside it in order to recognize the motion before issuing an alarm renders the invention commercially unsuitable for fall prevention. Once the person is standing, the invention provides nothing to prevent the individual from falling and any alarm is too late. This also holds true for an alarm if a person sitting on the edge of the bed as it results in reduced reaction time for a care giver to arrive before the person is standing. The fundamental drawback of the '934 patent is that the methods described with the various algorithms are only able to detect that a change has occurred between the current image and previous images. The '934 patent classifies all changes between images as motion and then attempts to measure the change at defined states (standing, lying on the floor, etc.). The limitations imposed by the '934 patent are due to the fact that the system uses "blobs", which is a term of art in the computer science field and can be generally regarded as a collection of binary data. Blobs do not provide any internal information and can only be characterized by their size and, if an edge detection algorithm is properly applied, information regarding their shape. In the case of the '934 patent, the disclosed invention makes use of the orientation, or aspect ratio of blobs to trigger alarm conditions without any knowledge of what the blob represents. Again, the '934 patent teaches away from real-time image processing and issuing an alarm by incorporating a delay period needed to confirm the orientation of the blob. The '934 patent does not contemplate any attempts to classify the 'type' of motion. It is necessary to detect and identify specific type of motion or postures in order to provide a reliable predictor, or notification, that a person is about to get out of bed.
All disclosed patient monitoring prior art incorporates the requirement to delay issuing an alarm to reduce the incidence of false alarm.
The need exists for an improved system and method that provides care takers with a reliable, advanced warning or notification that a patient is about to get out of bed without assistance and that does so without delay and a very low incidence of false alarms.

This patent is subject to a terminal disclaimer.


A method for driving a field-effect transistor having a source section, a drain section and a gate section, includes applying a gate voltage to the gate section and causing the formation and/or maintenance of an electrically conductive channel between the source section and the drain section. After the channel has been formed, the gate section is disconnected from a gate voltage supply source which applies the gate voltage to the gate section.

Field of the Invention
The present invention relates to a method for driving a field-effect transistor having a source section, a drain section and a gate section, which includes applying a gate voltage to the gate section and causing the formation and/or maintenance of an electrically conductive channel between the source section and the drain section.
Such field-effect transistors (FETS) and methods for driving them have been known for a long time. FIG. 4 shows a practical embodiment of such a transistor which is described below.
In the case of conventional field-effect transistors in steady-state operation, it is not possible to pass a voltage applied to the source or drain section through a gate voltage which is of equal magnitude or is lower. In fact, for that purpose the gate voltage must be changed to a level which is above the voltage to be passed through by an amount at least equal to a material-dependent threshold voltage for channel formation.
Particularly in digital technology, where field-effect transistors of the enhancement type are predominantly used, that is linked with not inconsiderable difficulties when it is intended to switch voltage levels which are above the supply voltage. The production of an additional voltage level for use as the gate voltage has until now been carried out through the use of so-called pumps, which raise a voltage at a low level (in steps if necessary) to a voltage at a higher level. The circuitry implementation of such pumps necessitates a multiplicity of additional electronic components (in particular transistors and capacitors), which is disadvantageous, above all in the case of integrated circuits (it is area-intensive and high and low voltage surfaces are difficult to isolate).

Method for driving a field-effect transistor


There is disclosed a door operation mechanism which can open/close a door to either right or left side. When a handle portion 116 is manually pivoted and displaced, it rotates cams 98 and 98a and, thus, a thrust-up rod 94 is pushed up and a push-down rod 94a is pushed down. The thrust-up rod 94 pushes and displaces a swing plate 66 in a hinge mechanism 16a. The push-down rod 94a pushes and displaces a swing place 66 in a hinge mechanism 16b. Then, the swing plates 66 in the hinge mechanisms 16a and 16b fail to bind hinge pins 22 and 26, respectively, and the right side of a door 14 is released. By pulling the right side of the door 14, the door 14 can be opened on the axis of hinge mechanisms 16c and 16d which are provided on the left side of the door. On the other hand, when a left unlocking mechanism 20b is operated, the door 14 can be opened on the axis of the hinge mechanisms 16a and 16b on the right side of the door. Therefore, the door 14 can be opened to either right or left side.

The present invention relates to a door operation mechanism for opening/closing a door.
In a conventional constitution, a furniture door or another door is interconnected on the left or right side with a body by a hinge or the like on which the door swings to open or close.
In this constitution, an object which interferes with a door cannot be placed in a range in which the door opens/closes. Also, in the case of a furniture door, the left or right side of the door needs to be positioned spaced from a wall in such a manner that the door is prevented from contacting the wall.
Additionally, in the case where doors are arranged in, for example, a locker room, when the locker doors open to the left side, one hesitates to or cannot easily open the door if the left-side locker is being used by another person. In this case, one waits for the neighboring person to leave before opening the door or carefully opens the door in such a manner that the door does not hit the neighboring person.
When the opening direction of the door is fixed in this manner, the aforementioned disadvantages are caused.


There is provided with a method performed in an image transmission apparatus capable of executing first communication and second communication whose communication speed is lower than that of the first communication with a display apparatus, including: generating an image to be displayed on the display apparatus; detecting whether the first communication is executable or not; transmitting the generated image to the display apparatus via the first communication when the first communication is executable; transmitting a compressed image obtained by compressing the generated image to the display apparatus via the second communication when the first communication is not executable; and transmitting compression utilization information required to display the compressed image on the display apparatus to the display apparatus via at least one of the first communication and the second communication when the first communication is executable.

1. Field of the Invention
The present invention relates to an image transmission apparatus which generates and transmits an image, a display apparatus which receives the image from the image transmission apparatus and displays the received image, and a method to be performed in these apparatuses.
2. Related Art
In JP-A 2002-304283 (KOKAI), there is described an example of a system in which an information processing apparatus (image transmission apparatus) and a display apparatus can be connected via multiple communication paths. When the information processing apparatus and the display apparatus are wiredly connected, the system according to JP-A 2002-304283 (KOKAI) transmits an image to be displayed on the display apparatus via the wired connection. When detecting that the wired connection has been cut, the system transmits the image to be displayed on the display apparatus via wireless connection.
Thereby, when using the display apparatus near the information processing apparatus, a user can work with a high graphic performance via wired connection. Furthermore, it is also possible to perform work using the display apparatus away from the information processing apparatus, and in this case, the display apparatus receives an image to be displayed from the information processing apparatus via wireless connection.
As a scheme for compressing and transmitting information to be displayed on the display apparatus, there is widely used a scheme in which a whole image as an image of one frame to be displayed on the display apparatus is transmitted first, and then an image of an area where change has been made is transmitted at predetermined time intervals (see JP-A 2004-86550 (KOKAI)).
When this scheme is applied to the system of JP-A 2002-304283 (KOKAI), the whole image to be displayed must be transmitted first immediately after switching to transmission via wireless communication, and a lot of time is required for the transmission when the usable band is narrow. Furthermore, since update of the displayed image starts after the whole image has been transmitted, a lot of time is required until the screen display is started.

Image transmission apparatus, display apparatus and method


Disclosed are a digital-analog converter and a camera module having the same. The digital-analog converter includes a plurality of decoders for receiving bits of a digital input signal by dividing the bits in a predetermined bit unit except for lower bits of the digital input signal, and decoding the bits into thermometer code signals, a delay unit for delaying output of the lower bits of the digital input signal, a latch unit for synchronizing output signals of the decoders with an output signal of the delay unit, and a current source for converting a digital signal output from the latch unit into an analog signal.

A digital-analog converter (DAC) is a device to change a digital signal into an analog signal. The DAC has been used in a wireless communication system, a voice and image signal processing device, and measurement equipment.
In addition, the DAC can control a motor by converting a digital signal into an analog signal. For example, the DAC may be used for a driver to drive a voice coil motor (VCM) constituting a camera module of a portable terminal.
The VCM of the camera module reciprocates within a relatively short distance. The reciprocation of the VCM changes the position of a lens, thereby providing an automatic focusing (AF) function for an object.
In order to drive the VCM used for the implementation of such an AF function, three factors of linearity, hysteresis, and sensitivity are important. Among this, the linearity is the most important factor.
The linearity is determined by the digital-analog converter. If the linearity of the DAC is degraded, the precise operation of the VCM is difficult, and the accuracy of the AF function of the camera module cannot be ensured.

Digital-analog converter and camera module having the same


Disclosed is an image forming apparatus which forms an image including an image forming unit to form the image on a paper, a plurality of paper ejection trays to mount the paper on which the image is formed, a display unit to display a setting screen for selecting at least one paper ejection tray for a reserved job among the paper ejection trays, detecting units to detect a present mounting amount of the paper in each paper ejection tray and a control unit to control the display of the setting screen, and the control unit simultaneously displays the detected mounting amount of each paper ejection tray on one setting screen.

1. Field of the Invention
The present invention relates to an image forming apparatus which forms an image on a paper.
2. Description of Related Art
In an image forming apparatus, papers which are ejected after an image is formed are mounted on a paper ejection tray. When the mounting amount reaches the maximum mounting amount of the paper ejection tray, the image forming itself is once stopped in the image forming apparatus or the paper ejection is switched to a different paper ejection tray.
In the case where the image forming itself is stopped once, the operation rate of the image forming apparatus declines while the image forming is stopped. Because the image forming does not restart unless a user takes out the mounted papers from the paper ejection tray, a user has to always check the mounting amount when the image forming is carried out continuously. Further, in case where the paper ejection is switched to a different paper ejection tray, it is cumbersome because a user has to collect the mounted papers from each of the different paper ejection trays.
For the above problems, a method for calculating and displaying the time needed to reach the maximum mounting amount of the paper election tray from the present mounting amount of the paper ejection tray so that a user can easily check the mounting amount of the paper ejection tray is disclosed (for example, see JP2004-175513A). Further, there is an image forming apparatus in which the ejection amount for one job is calculated in the image forming apparatus and the paper ejection tray which can house all the calculated amount of ejected paper is determined and output so that the papers of one job are to be ejected to the same paper ejection tray (for example, see JP5-155511A).
However, in the method of above described JP2004-175513A, the mounting amount of only one of the paper ejection trays is displayed and only the time needed for the paper ejection tray to reach the maximum mounting amount after the execution of the actual image forming is started can be known. In such way, the over all mounting status cannot be known when there are a plurality of paper ejection trays, and a user cannot select the appropriate paper ejection tray when a user herself/himself is selecting the paper ejection tray.
Moreover, in the method according to JP5-155511A, a user cannot confirm to which paper ejection tray the papers are to be ejected before the image forming because the image forming apparatus automatically assigns where the papers are to be ejected.
Further, a user herself/himself cannot select the paper ejection tray to which she/he desires the papers to be ejected.

Konica Minolta Business Technologies, Inc.